diff mbox

[v6] media: platform: Renesas IMR driver

Message ID 20170623203456.503714406@cogentembedded.com (mailing list archive)
State Superseded
Delegated to: Geert Uytterhoeven
Headers show

Commit Message

Sergei Shtylyov June 23, 2017, 8:34 p.m. UTC
From: Konstantin Kozhevnikov <Konstantin.Kozhevnikov@cogentembedded.com>

The image renderer, or the distortion correction engine, is a drawing
processor with a simple instruction system capable of referencing video
capture data or data in an external memory as the 2D texture data and
performing texture mapping and drawing with respect to any shape that is
split into triangular objects.

This V4L2 memory-to-memory device driver only supports image renderer light
extended 4 (IMR-LX4) found in the R-Car gen3 SoCs; the R-Car gen2 support
can be added later...

[Sergei: merged 2 original patches, added  the patch description, removed
unrelated parts,  added the binding document and the UAPI documentation,
ported the driver to the modern kernel, renamed the UAPI header file and
the guard macros to match the driver name, extended the copyrights, fixed
up Kconfig prompt/depends/help, made use of the BIT/GENMASK() macros,
sorted  #include's, replaced 'imr_ctx::crop' array with the 'imr_ctx::rect'
structure, replaced imr_{g|s}_crop() with imr_{g|s}_selection(), completely
rewrote imr_queue_setup(), removed 'imr_format_info::name', moved the
applicable code from imr_buf_queue() to imr_buf_prepare() and moved the
rest of imr_buf_queue() after imr_buf_finish(), assigned 'src_vq->dev' and
'dst_vq->dev' in imr_queue_init(), removed imr_start_streaming(), assigned
'src_vq->dev' and 'dst_vq->dev' in imr_queue_init(), clarified the math in
imt_tri_type_{a|b|c}_length(), clarified the pointer math and avoided casts
to 'void *' in imr_tri_set_type_{a|b|c}(), replaced imr_{reqbufs|querybuf|
dqbuf|expbuf|streamon|streamoff}() with the generic helpers, implemented
vidioc_{create_bufs|prepare_buf}() methods, used ALIGN() macro and merged
the matrix size checks and replaced kmalloc()/copy_from_user() calls with
memdup_user() call in imr_ioctl_map(), moved setting device capabilities
from imr_querycap() to imr_probe(), set the valid default queue format in
imr_probe(), removed leading dots and fixed grammar in the comments, fixed
up  the indentation  to use  tabs where possible, renamed DLSR, CMRCR.
DY1{0|2}, and ICR bits to match the manual, changed the prefixes of the
CMRCR[2]/TRI{M|C}R bits/fields to match the manual, removed non-existent
TRIMR.D{Y|U}D{X|V}M bits, added/used the IMR/{UV|CP}DPOR/SUSR bits/fields/
shifts, separated the register offset/bit #define's, sorted instruction
macros by opcode, removed unsupported LINE instruction, masked the register
address in WTL[2]/WTS instruction macros, moved the display list #define's
after the register #define's, removing the redundant comment, avoided
setting reserved bits when writing CMRCCR[2]/TRIMCR, used the SR bits
instead of a bare number, removed *inline* from .c file, fixed lines over
80 columns, removed useless spaces, comments, parens, operators, casts,
braces, variables, #include's, statements, and even 1 function, added
useful local variable, uppercased and spelled out the abbreviations,
made comment wording more consistent/correct, fixed the comment typos,
reformatted some multiline comments, inserted empty line after declaration,
removed extra empty lines,  reordered some local variable desclarations,
removed calls to 4l2_err() on kmalloc() failure, replaced '*' with 'x'
in some format strings for v4l2_dbg(), fixed the error returned by
imr_default(), avoided code duplication in the IRQ handler, used '__packed'
for the UAPI structures, declared 'imr_map_desc::data' as '__u64' instead
of 'void *', switched to '__u{16|32}' in the UAPI header, enclosed the
macro parameters in parens, exchanged the values of IMR_MAP_AUTO{S|D}G
macros.]

Signed-off-by: Konstantin Kozhevnikov <Konstantin.Kozhevnikov@cogentembedded.com>
Signed-off-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>

---
Changes in version 6:
- fixed the bug where if imr_cfg_create() fails, 'ctx->cfg' wasn't set to NULL
  and so wouldn't fail the validity checks;
- fixed the height minimum/alignment passed to v4l_bound_align_image();
- removed the buggy !V4L2_TYPE_IS_OUTPUT() check from imr_qbuf();
- added the driver UAPI documentation;
- replaced 'imr_ctx::crop' array with the 'imr_ctx::rect' structure;
- replaced imr_{g|s}_crop() with imr_{g|s}_selection();
- removed 'imr_format_info::name' and the related code;
- completely rewrote imr_queue_setup();
- moved the applicable code from imr_buf_queue() to imr_buf_prepare(), moved
  the  rest of imr_buf_queue() after imr_buf_finish();
- removed imr_start_streaming();
- assigned 'src_vq->dev' and 'dst_vq->dev' in imr_queue_init();
- clarified the math in imt_tri_type_{a|b|c}_length();
- removed useless local variables, added useful variables, avoided casts to
  'void *', and clarified the pointer math in imr_tri_set_type_{a|b|c}();
- replaced kmalloc()/copy_from_user() calls with memdup_user() call;
- moved the 'type' variable assignment in imr_ioctl_map() after the following
  comment;
- merged the matrix size checks for the cases of the automatic generation
  pattern and the absolute coordinates in imr_ioctl_map();
- swapped the operands in the VBO size check in imr_ioctl_map();
- moved setting device capabilities from imr_querycap() to imr_probe();
- replaced imr_{reqbufs|querybuf|dqbuf|expbuf|streamon|streamoff}() with the
  generic helpers, implemented vidioc_{create_bufs|prepare_buf}() methods;
- set the valid default queue pixel format in imr_probe();
- used tabs for indentation where possible in imr_probe();
- removed the rest of the *inline* keywords;
- declared 'imr_map_desc::data' as '__u64' instead of 'void *';
- switched to '__u{16|32}' instead of 'u{16|32}' in the UAPI header;
- spelled out the VBO abbreviation and removed redundancy in the UAPI header
  comments.

Changes in version 5:
- used ALIGN() macro in imr_ioctl_map();
- moved the display list #define's after the register #define's, removing the
  redundant comment;
- uppercased the "tbd" abbreviation in the comments;
- made the TRI instruction types A/B/C named consistently;
- avoided quotes around the coordinate's names;
- avoided some  hyphens in the comments;
- removed spaces around / and before ? in the comments;
- reworded some comments;
- reformatted some multiline comments;
- fixed typos in the comments.

Changes in version 4:
- added/used the SUSR fields/shifts.

Changes in version 3:
- added/used the {UV|CP}DPOR fields/shifts;
- removed unsupported LINE instruction;
- replaced '*' with 'x' in the string passed to v4l2_dbg() in
  imr_dl_program_setup();
- switched to prepending the SoC model to "imr-lx4" in the "compatible" prop
  strings.

Changes in version 2:
- renamed the ICR bits to match the manual;
- added/used  the IMR bits;
- changed the prefixes of the CMRCR[2]/TRI{M|C}R bits/fields to match the
  manual;
- renamed the CMRCR.DY1{0|2} bits to match the manual;
- removed non-existent TRIMR.D{Y|U}D{X|V}M bits;
- used the SR bits instead of a bare number;
- sorted the instruction macros by opcode, removing redundant parens;
- masked the register address in WTL[2]/WTS instruction macros;
- avoided setting reserved bits when writing to CMRCCR[2]/TRIMCR;
- mentioned the video capture data as a texture source in the binding and the
  patch description;
- documented the SoC specific "compatible" values;
- clarified the "interrupts" and "clocks" property text;
- updated the patch description.

 Documentation/devicetree/bindings/media/rcar_imr.txt |   27 
 Documentation/media/v4l-drivers/index.rst            |    1 
 Documentation/media/v4l-drivers/rcar_imr.rst         |   86 
 drivers/media/platform/Kconfig                       |   13 
 drivers/media/platform/Makefile                      |    1 
 drivers/media/platform/rcar_imr.c                    | 1877 +++++++++++++++++++
 include/uapi/linux/rcar_imr.h                        |   94 
 7 files changed, 2099 insertions(+)

Comments

Rob Herring (Arm) June 26, 2017, 7:49 p.m. UTC | #1
On Fri, Jun 23, 2017 at 11:34:44PM +0300, Sergei Shtylyov wrote:
> From: Konstantin Kozhevnikov <Konstantin.Kozhevnikov@cogentembedded.com>
> 
> The image renderer, or the distortion correction engine, is a drawing
> processor with a simple instruction system capable of referencing video
> capture data or data in an external memory as the 2D texture data and
> performing texture mapping and drawing with respect to any shape that is
> split into triangular objects.
> 
> This V4L2 memory-to-memory device driver only supports image renderer light
> extended 4 (IMR-LX4) found in the R-Car gen3 SoCs; the R-Car gen2 support
> can be added later...
> 
> [Sergei: merged 2 original patches, added  the patch description, removed
> unrelated parts,  added the binding document and the UAPI documentation,
> ported the driver to the modern kernel, renamed the UAPI header file and
> the guard macros to match the driver name, extended the copyrights, fixed
> up Kconfig prompt/depends/help, made use of the BIT/GENMASK() macros,
> sorted  #include's, replaced 'imr_ctx::crop' array with the 'imr_ctx::rect'
> structure, replaced imr_{g|s}_crop() with imr_{g|s}_selection(), completely
> rewrote imr_queue_setup(), removed 'imr_format_info::name', moved the
> applicable code from imr_buf_queue() to imr_buf_prepare() and moved the
> rest of imr_buf_queue() after imr_buf_finish(), assigned 'src_vq->dev' and
> 'dst_vq->dev' in imr_queue_init(), removed imr_start_streaming(), assigned
> 'src_vq->dev' and 'dst_vq->dev' in imr_queue_init(), clarified the math in
> imt_tri_type_{a|b|c}_length(), clarified the pointer math and avoided casts
> to 'void *' in imr_tri_set_type_{a|b|c}(), replaced imr_{reqbufs|querybuf|
> dqbuf|expbuf|streamon|streamoff}() with the generic helpers, implemented
> vidioc_{create_bufs|prepare_buf}() methods, used ALIGN() macro and merged
> the matrix size checks and replaced kmalloc()/copy_from_user() calls with
> memdup_user() call in imr_ioctl_map(), moved setting device capabilities
> from imr_querycap() to imr_probe(), set the valid default queue format in
> imr_probe(), removed leading dots and fixed grammar in the comments, fixed
> up  the indentation  to use  tabs where possible, renamed DLSR, CMRCR.
> DY1{0|2}, and ICR bits to match the manual, changed the prefixes of the
> CMRCR[2]/TRI{M|C}R bits/fields to match the manual, removed non-existent
> TRIMR.D{Y|U}D{X|V}M bits, added/used the IMR/{UV|CP}DPOR/SUSR bits/fields/
> shifts, separated the register offset/bit #define's, sorted instruction
> macros by opcode, removed unsupported LINE instruction, masked the register
> address in WTL[2]/WTS instruction macros, moved the display list #define's
> after the register #define's, removing the redundant comment, avoided
> setting reserved bits when writing CMRCCR[2]/TRIMCR, used the SR bits
> instead of a bare number, removed *inline* from .c file, fixed lines over
> 80 columns, removed useless spaces, comments, parens, operators, casts,
> braces, variables, #include's, statements, and even 1 function, added
> useful local variable, uppercased and spelled out the abbreviations,
> made comment wording more consistent/correct, fixed the comment typos,
> reformatted some multiline comments, inserted empty line after declaration,
> removed extra empty lines,  reordered some local variable desclarations,
> removed calls to 4l2_err() on kmalloc() failure, replaced '*' with 'x'
> in some format strings for v4l2_dbg(), fixed the error returned by
> imr_default(), avoided code duplication in the IRQ handler, used '__packed'
> for the UAPI structures, declared 'imr_map_desc::data' as '__u64' instead
> of 'void *', switched to '__u{16|32}' in the UAPI header, enclosed the
> macro parameters in parens, exchanged the values of IMR_MAP_AUTO{S|D}G
> macros.]

TL;DR needed here IMO. Not sure anyone really cares every detail you 
changed in re-writing this. If they did, it should all be separate 
commits.

> Signed-off-by: Konstantin Kozhevnikov <Konstantin.Kozhevnikov@cogentembedded.com>
> Signed-off-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>

I acked v5 and it doesn't seem the binding changed.

Rob
Sergei Shtylyov June 26, 2017, 7:56 p.m. UTC | #2
Hello!

On 06/26/2017 10:49 PM, Rob Herring wrote:

>> From: Konstantin Kozhevnikov <Konstantin.Kozhevnikov@cogentembedded.com>
>>
>> The image renderer, or the distortion correction engine, is a drawing
>> processor with a simple instruction system capable of referencing video
>> capture data or data in an external memory as the 2D texture data and
>> performing texture mapping and drawing with respect to any shape that is
>> split into triangular objects.
>>
>> This V4L2 memory-to-memory device driver only supports image renderer light
>> extended 4 (IMR-LX4) found in the R-Car gen3 SoCs; the R-Car gen2 support
>> can be added later...
>>
>> [Sergei: merged 2 original patches, added  the patch description, removed
>> unrelated parts,  added the binding document and the UAPI documentation,
>> ported the driver to the modern kernel, renamed the UAPI header file and
>> the guard macros to match the driver name, extended the copyrights, fixed
>> up Kconfig prompt/depends/help, made use of the BIT/GENMASK() macros,
>> sorted  #include's, replaced 'imr_ctx::crop' array with the 'imr_ctx::rect'
>> structure, replaced imr_{g|s}_crop() with imr_{g|s}_selection(), completely
>> rewrote imr_queue_setup(), removed 'imr_format_info::name', moved the
>> applicable code from imr_buf_queue() to imr_buf_prepare() and moved the
>> rest of imr_buf_queue() after imr_buf_finish(), assigned 'src_vq->dev' and
>> 'dst_vq->dev' in imr_queue_init(), removed imr_start_streaming(), assigned
>> 'src_vq->dev' and 'dst_vq->dev' in imr_queue_init(), clarified the math in
>> imt_tri_type_{a|b|c}_length(), clarified the pointer math and avoided casts
>> to 'void *' in imr_tri_set_type_{a|b|c}(), replaced imr_{reqbufs|querybuf|
>> dqbuf|expbuf|streamon|streamoff}() with the generic helpers, implemented
>> vidioc_{create_bufs|prepare_buf}() methods, used ALIGN() macro and merged
>> the matrix size checks and replaced kmalloc()/copy_from_user() calls with
>> memdup_user() call in imr_ioctl_map(), moved setting device capabilities
>> from imr_querycap() to imr_probe(), set the valid default queue format in
>> imr_probe(), removed leading dots and fixed grammar in the comments, fixed
>> up  the indentation  to use  tabs where possible, renamed DLSR, CMRCR.
>> DY1{0|2}, and ICR bits to match the manual, changed the prefixes of the
>> CMRCR[2]/TRI{M|C}R bits/fields to match the manual, removed non-existent
>> TRIMR.D{Y|U}D{X|V}M bits, added/used the IMR/{UV|CP}DPOR/SUSR bits/fields/
>> shifts, separated the register offset/bit #define's, sorted instruction
>> macros by opcode, removed unsupported LINE instruction, masked the register
>> address in WTL[2]/WTS instruction macros, moved the display list #define's
>> after the register #define's, removing the redundant comment, avoided
>> setting reserved bits when writing CMRCCR[2]/TRIMCR, used the SR bits
>> instead of a bare number, removed *inline* from .c file, fixed lines over
>> 80 columns, removed useless spaces, comments, parens, operators, casts,
>> braces, variables, #include's, statements, and even 1 function, added
>> useful local variable, uppercased and spelled out the abbreviations,
>> made comment wording more consistent/correct, fixed the comment typos,
>> reformatted some multiline comments, inserted empty line after declaration,
>> removed extra empty lines,  reordered some local variable desclarations,
>> removed calls to 4l2_err() on kmalloc() failure, replaced '*' with 'x'
>> in some format strings for v4l2_dbg(), fixed the error returned by
>> imr_default(), avoided code duplication in the IRQ handler, used '__packed'
>> for the UAPI structures, declared 'imr_map_desc::data' as '__u64' instead
>> of 'void *', switched to '__u{16|32}' in the UAPI header, enclosed the
>> macro parameters in parens, exchanged the values of IMR_MAP_AUTO{S|D}G
>> macros.]
>
> TL;DR needed here IMO.

    Not sure I understand... stands for "too long; didn't read", right?

> Not sure anyone really cares every detail you
> changed in re-writing this. If they did, it should all be separate
> commits.

    AFAIK this is a way that's things are dealt with when you submit somebody 
else's work with your changes. Sorry if the list is too long...

>> Signed-off-by: Konstantin Kozhevnikov <Konstantin.Kozhevnikov@cogentembedded.com>
>> Signed-off-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
>
> I acked v5 and it doesn't seem the binding changed.

    Sorry, I realized that I'd missed to collect you ACK just after sending 
v6... I believe there'll be v7 yet, so I'll finally collect it.

> Rob

MBR, Sergei
Geert Uytterhoeven June 26, 2017, 8:02 p.m. UTC | #3
Hi Sergei,

On Mon, Jun 26, 2017 at 9:56 PM, Sergei Shtylyov
<sergei.shtylyov@cogentembedded.com> wrote:
> On 06/26/2017 10:49 PM, Rob Herring wrote:
>>> From: Konstantin Kozhevnikov <Konstantin.Kozhevnikov@cogentembedded.com>
>>>
>>> The image renderer, or the distortion correction engine, is a drawing
>>> processor with a simple instruction system capable of referencing video
>>> capture data or data in an external memory as the 2D texture data and
>>> performing texture mapping and drawing with respect to any shape that is
>>> split into triangular objects.
>>>
>>> This V4L2 memory-to-memory device driver only supports image renderer
>>> light
>>> extended 4 (IMR-LX4) found in the R-Car gen3 SoCs; the R-Car gen2 support
>>> can be added later...
>>>
>>> [Sergei: merged 2 original patches, added  the patch description, removed

[...]

>>> macros.]
>>
>>
>> TL;DR needed here IMO.
>
>    Not sure I understand... stands for "too long; didn't read", right?
>
>> Not sure anyone really cares every detail you
>> changed in re-writing this. If they did, it should all be separate
>> commits.
>
>    AFAIK this is a way that's things are dealt with when you submit somebody
> else's work with your changes. Sorry if the list is too long...

Based on a patch by Konstantin Kozhevnikov
<Konstantin.Kozhevnikov@cogentembedded.com>?

Of course, that's bad for your coworker's patch statistics...

Gr{oetje,eeting}s,

                        Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds
Hans Verkuil July 3, 2017, 12:25 p.m. UTC | #4
Hi Sergei,

Some comments below:

On 06/23/2017 10:34 PM, Sergei Shtylyov wrote:
> From: Konstantin Kozhevnikov <Konstantin.Kozhevnikov@cogentembedded.com>
> 
> The image renderer, or the distortion correction engine, is a drawing
> processor with a simple instruction system capable of referencing video
> capture data or data in an external memory as the 2D texture data and
> performing texture mapping and drawing with respect to any shape that is
> split into triangular objects.
> 
> This V4L2 memory-to-memory device driver only supports image renderer light
> extended 4 (IMR-LX4) found in the R-Car gen3 SoCs; the R-Car gen2 support
> can be added later...
> 
> [Sergei: merged 2 original patches, added  the patch description, removed
> unrelated parts,  added the binding document and the UAPI documentation,
> ported the driver to the modern kernel, renamed the UAPI header file and
> the guard macros to match the driver name, extended the copyrights, fixed
> up Kconfig prompt/depends/help, made use of the BIT/GENMASK() macros,
> sorted  #include's, replaced 'imr_ctx::crop' array with the 'imr_ctx::rect'
> structure, replaced imr_{g|s}_crop() with imr_{g|s}_selection(), completely
> rewrote imr_queue_setup(), removed 'imr_format_info::name', moved the
> applicable code from imr_buf_queue() to imr_buf_prepare() and moved the
> rest of imr_buf_queue() after imr_buf_finish(), assigned 'src_vq->dev' and
> 'dst_vq->dev' in imr_queue_init(), removed imr_start_streaming(), assigned
> 'src_vq->dev' and 'dst_vq->dev' in imr_queue_init(), clarified the math in
> imt_tri_type_{a|b|c}_length(), clarified the pointer math and avoided casts
> to 'void *' in imr_tri_set_type_{a|b|c}(), replaced imr_{reqbufs|querybuf|
> dqbuf|expbuf|streamon|streamoff}() with the generic helpers, implemented
> vidioc_{create_bufs|prepare_buf}() methods, used ALIGN() macro and merged
> the matrix size checks and replaced kmalloc()/copy_from_user() calls with
> memdup_user() call in imr_ioctl_map(), moved setting device capabilities
> from imr_querycap() to imr_probe(), set the valid default queue format in
> imr_probe(), removed leading dots and fixed grammar in the comments, fixed
> up  the indentation  to use  tabs where possible, renamed DLSR, CMRCR.
> DY1{0|2}, and ICR bits to match the manual, changed the prefixes of the
> CMRCR[2]/TRI{M|C}R bits/fields to match the manual, removed non-existent
> TRIMR.D{Y|U}D{X|V}M bits, added/used the IMR/{UV|CP}DPOR/SUSR bits/fields/
> shifts, separated the register offset/bit #define's, sorted instruction
> macros by opcode, removed unsupported LINE instruction, masked the register
> address in WTL[2]/WTS instruction macros, moved the display list #define's
> after the register #define's, removing the redundant comment, avoided
> setting reserved bits when writing CMRCCR[2]/TRIMCR, used the SR bits
> instead of a bare number, removed *inline* from .c file, fixed lines over
> 80 columns, removed useless spaces, comments, parens, operators, casts,
> braces, variables, #include's, statements, and even 1 function, added
> useful local variable, uppercased and spelled out the abbreviations,
> made comment wording more consistent/correct, fixed the comment typos,
> reformatted some multiline comments, inserted empty line after declaration,
> removed extra empty lines,  reordered some local variable desclarations,
> removed calls to 4l2_err() on kmalloc() failure, replaced '*' with 'x'
> in some format strings for v4l2_dbg(), fixed the error returned by
> imr_default(), avoided code duplication in the IRQ handler, used '__packed'
> for the UAPI structures, declared 'imr_map_desc::data' as '__u64' instead
> of 'void *', switched to '__u{16|32}' in the UAPI header, enclosed the
> macro parameters in parens, exchanged the values of IMR_MAP_AUTO{S|D}G
> macros.]

As Geert suggested, just replace this with a 'Based-on' line.

<snip>

> Index: media_tree/drivers/media/platform/rcar_imr.c
> ===================================================================
> --- /dev/null
> +++ media_tree/drivers/media/platform/rcar_imr.c
> @@ -0,0 +1,1877 @@

<snip>

> +/* add reference to the current configuration */
> +static struct imr_cfg *imr_cfg_ref(struct imr_ctx *ctx)

imr_cfg_ref -> imr_cfg_ref_get

> +{
> +	struct imr_cfg *cfg = ctx->cfg;
> +
> +	BUG_ON(!cfg);

Perhaps this can be replaced by:

	if (WARN_ON(!cfg))
		return NULL;

> +	cfg->refcount++;
> +	return cfg;
> +}
> +
> +/* mesh configuration destructor */
> +static void imr_cfg_unref(struct imr_ctx *ctx, struct imr_cfg *cfg)

imr_cfg_unref -> imr_cfg_ref_put

That follows the standard naming conventions for refcounting.

> +{
> +	struct imr_device *imr = ctx->imr;
> +
> +	/* no atomicity is required as operation is locked with device mutex */
> +	if (!cfg || --cfg->refcount)
> +		return;
> +
> +	/* release memory allocated for a display list */
> +	if (cfg->dl_vaddr)
> +		dma_free_writecombine(imr->dev, cfg->dl_size, cfg->dl_vaddr,
> +				      cfg->dl_dma_addr);
> +
> +	/* destroy the configuration structure */
> +	kfree(cfg);

Add:
	ctx->cfg = NULL;

> +
> +	/* decrement number of active configurations (debugging) */
> +	WARN_ON(!ctx->cfg_num--);
> +}
> +
> +/*******************************************************************************
> + * Context processing queue
> + ******************************************************************************/
> +
> +static int imr_queue_setup(struct vb2_queue *vq,
> +			   unsigned int *nbuffers, unsigned int *nplanes,
> +			   unsigned int sizes[], struct device *alloc_devs[])
> +{
> +	struct imr_ctx		*ctx = vb2_get_drv_priv(vq);
> +	struct imr_q_data	*q_data = &ctx->queue
> +					[V4L2_TYPE_IS_OUTPUT(vq->type) ? 0 : 1];
> +
> +	if (*nplanes)
> +		return sizes[0] < q_data->fmt.sizeimage ? -EINVAL : 0;
> +
> +	/* we use only single-plane formats */
> +	*nplanes = 1;
> +	sizes[0] = q_data->fmt.sizeimage;
> +
> +	return 0;
> +}
> +
> +static int imr_buf_prepare(struct vb2_buffer *vb)
> +{
> +	struct vb2_v4l2_buffer	*vbuf = to_vb2_v4l2_buffer(vb);
> +	struct vb2_queue	*q = vb->vb2_queue;
> +	struct imr_ctx		*ctx = vb2_get_drv_priv(q);
> +
> +	WARN_ON_ONCE(!mutex_is_locked(&ctx->imr->mutex));
> +
> +	v4l2_dbg(3, debug, &ctx->imr->v4l2_dev,
> +		 "%sput buffer <0x%08llx> prepared\n",
> +		 q->is_output ? "in" : "out",
> +		 (u64)vb2_dma_contig_plane_dma_addr(vb, 0));
> +
> +	/*
> +	 * for input buffer, put current configuration pointer
> +	 * (add reference)
> +	 */
> +	if (q->is_output)
> +		to_imr_buffer(vbuf)->cfg = imr_cfg_ref(ctx);
> +
> +	return 0;
> +}
> +
> +static void imr_buf_finish(struct vb2_buffer *vb)
> +{
> +	struct vb2_v4l2_buffer	*vbuf = to_vb2_v4l2_buffer(vb);
> +	struct vb2_queue	*q = vb->vb2_queue;
> +	struct imr_ctx		*ctx = vb2_get_drv_priv(q);
> +
> +	WARN_ON(!mutex_is_locked(&ctx->imr->mutex));
> +
> +	/* any special processing of completed buffer? - TBD */
> +	v4l2_dbg(3, debug, &ctx->imr->v4l2_dev,
> +		 "%sput buffer <0x%08llx> done\n", q->is_output ? "in" : "out",
> +		 (u64)vb2_dma_contig_plane_dma_addr(vb, 0));
> +
> +	/* unref configuration pointer as needed */
> +	if (q->is_output)
> +		imr_cfg_unref(ctx, to_imr_buffer(vbuf)->cfg);
> +}
> +
> +static void imr_buf_queue(struct vb2_buffer *vb)
> +{
> +	struct vb2_v4l2_buffer	*vbuf = to_vb2_v4l2_buffer(vb);
> +	struct vb2_queue	*q = vb->vb2_queue;
> +	struct imr_ctx		*ctx = vb2_get_drv_priv(q);
> +
> +	v4l2_dbg(3, debug, &ctx->imr->v4l2_dev,
> +		 "%sput buffer <0x%08llx> queued\n",
> +		 q->is_output ? "in" : "out",
> +		 (u64)vb2_dma_contig_plane_dma_addr(vb, 0));
> +
> +	v4l2_m2m_buf_queue(ctx->m2m_ctx, vbuf);
> +}
> +
> +static void imr_stop_streaming(struct vb2_queue *vq)
> +{
> +	struct imr_ctx		*ctx = vb2_get_drv_priv(vq);
> +	unsigned long		flags;
> +	struct vb2_v4l2_buffer	*vb;
> +
> +	spin_lock_irqsave(&ctx->imr->lock, flags);
> +
> +	/* purge all buffers from a queue */
> +	if (V4L2_TYPE_IS_OUTPUT(vq->type)) {
> +		while ((vb = v4l2_m2m_src_buf_remove(ctx->m2m_ctx)) != NULL)
> +			v4l2_m2m_buf_done(vb, VB2_BUF_STATE_ERROR);
> +	} else {
> +		while ((vb = v4l2_m2m_dst_buf_remove(ctx->m2m_ctx)) != NULL)
> +			v4l2_m2m_buf_done(vb, VB2_BUF_STATE_ERROR);
> +	}
> +
> +	spin_unlock_irqrestore(&ctx->imr->lock, flags);
> +
> +	v4l2_dbg(1, debug, &ctx->imr->v4l2_dev, "%s streaming stopped\n",
> +		 V4L2_TYPE_IS_OUTPUT(vq->type) ? "output" : "capture");
> +}
> +
> +/* buffer queue operations */
> +static struct vb2_ops imr_qops = {
> +	.queue_setup	= imr_queue_setup,
> +	.buf_prepare	= imr_buf_prepare,
> +	.buf_finish	= imr_buf_finish,
> +	.buf_queue	= imr_buf_queue,
> +	.stop_streaming	= imr_stop_streaming,
> +	.wait_prepare	= vb2_ops_wait_prepare,
> +	.wait_finish	= vb2_ops_wait_finish,
> +};
> +
> +/* M2M device processing queue initialization */
> +static int imr_queue_init(void *priv, struct vb2_queue *src_vq,
> +			  struct vb2_queue *dst_vq)
> +{
> +	struct imr_ctx	*ctx = priv;
> +	int		ret;
> +
> +	memset(src_vq, 0, sizeof(*src_vq));
> +	src_vq->type = V4L2_BUF_TYPE_VIDEO_OUTPUT;
> +	src_vq->io_modes = VB2_MMAP | VB2_USERPTR | VB2_DMABUF;

Why do you need VB2_USERPTR? Unless you have a compelling reason for this
you should drop it here and in dst_vq->io_modes.

It should not be used in combination with contiguous DMA.

> +	src_vq->drv_priv = ctx;
> +	src_vq->buf_struct_size = sizeof(struct imr_buffer);
> +	src_vq->ops = &imr_qops;
> +	src_vq->mem_ops = &vb2_dma_contig_memops;
> +	src_vq->timestamp_flags = V4L2_BUF_FLAG_TIMESTAMP_MONOTONIC;
> +	src_vq->lock = &ctx->imr->mutex;
> +	src_vq->dev = ctx->imr->v4l2_dev.dev;
> +	ret = vb2_queue_init(src_vq);
> +	if (ret)
> +		return ret;
> +
> +	memset(dst_vq, 0, sizeof(*dst_vq));
> +	dst_vq->type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
> +	dst_vq->io_modes = VB2_MMAP | VB2_USERPTR | VB2_DMABUF;
> +	dst_vq->drv_priv = ctx;
> +	dst_vq->buf_struct_size = sizeof(struct v4l2_m2m_buffer);
> +	dst_vq->ops = &imr_qops;
> +	dst_vq->mem_ops = &vb2_dma_contig_memops;
> +	dst_vq->timestamp_flags = V4L2_BUF_FLAG_TIMESTAMP_MONOTONIC;
> +	dst_vq->lock = &ctx->imr->mutex;
> +	dst_vq->dev = ctx->imr->v4l2_dev.dev;
> +	return vb2_queue_init(dst_vq);
> +}
> +
> +/*******************************************************************************
> + * Operation type decoding helpers
> + ******************************************************************************/
> +
> +static u16 __imr_auto_sg_dg_tcm(u32 type)
> +{
> +	return	(type & IMR_MAP_AUTOSG ? IMR_TRIMR_AUTOSG :
> +		(type & IMR_MAP_AUTODG ? IMR_TRIMR_AUTODG : 0)) |
> +		(type & IMR_MAP_TCM ? IMR_TRIMR_TCM : 0);
> +}
> +
> +static u16 __imr_uvdp(u32 type)
> +{
> +	return (__IMR_MAP_UVDPOR(type) << IMR_UVDPOR_UVDPO_SHIFT) |
> +	       (type & IMR_MAP_DDP ? IMR_UVDPOR_DDP : 0);
> +}
> +
> +static u16 __imr_cpdp(u32 type)
> +{
> +	return (__IMR_MAP_YLDPO(type) << IMR_CPDPOR_YLDPO_SHIFT) |
> +	       (__IMR_MAP_UBDPO(type) << IMR_CPDPOR_UBDPO_SHIFT) |
> +	       (__IMR_MAP_VRDPO(type) << IMR_CPDPOR_VRDPO_SHIFT);
> +}
> +
> +static u16 __imr_luce(u32 type)
> +{
> +	return type & IMR_MAP_LUCE ? IMR_CMRCR_LUCE : 0;
> +}
> +
> +static u16 __imr_clce(u32 type)
> +{
> +	return type & IMR_MAP_CLCE ? IMR_CMRCR_CLCE : 0;
> +}
> +
> +/*******************************************************************************
> + * Type A (absolute coordinates of source/destination) mapping
> + ******************************************************************************/
> +
> +/* return size of the subroutine for type A mapping */
> +static u32 imr_tri_type_a_get_length(struct imr_mesh *mesh, int item_size)
> +{
> +	return ((1 + mesh->columns * (2 * item_size / sizeof(u32))) *
> +		(mesh->rows - 1) + 1) * sizeof(u32);
> +}
> +
> +/* set a mesh rows * columns using absolute coordinates */
> +static u32 *imr_tri_set_type_a(u32 *dl, void *map, struct imr_mesh *mesh,
> +			       int item_size)
> +{
> +	int columns = mesh->columns;
> +	int i, j;
> +
> +	/* convert lattice into set of stripes */
> +	for (i = 0; i < mesh->rows - 1; i++) {
> +		*dl++ = IMR_OP_TRI(2 * columns);
> +		for (j = 0; j < columns; j++) {
> +			memcpy(dl, map, item_size);
> +			dl  += item_size / sizeof(u32);
> +			memcpy(dl, map + columns * item_size, item_size);
> +			dl  += item_size / sizeof(u32);
> +			map += item_size;
> +		}
> +	}
> +
> +	*dl++ = IMR_OP_RET;
> +	return dl;
> +}
> +
> +/*******************************************************************************
> + * Type B mapping (automatically generated source or destination coordinates)
> + ******************************************************************************/
> +
> +/* calculate length of a type B mapping */
> +static u32 imr_tri_type_b_get_length(struct imr_mesh *mesh, int item_size)
> +{
> +	return (3 + (2 + (mesh->columns * (2 * item_size / sizeof(u32))) *
> +		     (mesh->rows - 1)) + 1) * sizeof(u32);
> +}
> +
> +/* set an auto-generated mesh n * m for a source/destination */
> +static u32 *imr_tri_set_type_b(u32 *dl, void *map, struct imr_mesh *mesh,
> +			       int item_size)
> +{
> +	int columns = mesh->columns;
> +	int i, j, y;
> +
> +	/* set mesh configuration */
> +	*dl++ = IMR_OP_WTS(IMR_AMXSR, mesh->dx);
> +	*dl++ = IMR_OP_WTS(IMR_AMYSR, mesh->dy);
> +
> +	/* origin by X coordinate is the same across all rows */
> +	*dl++ = IMR_OP_WTS(IMR_AMXOR, mesh->x0);
> +
> +	/* convert lattice into set of stripes */
> +	for (i = 0, y = mesh->y0; i < mesh->rows - 1; i++, y += mesh->dy) {
> +		/* set origin by Y coordinate for a current row */
> +		*dl++ = IMR_OP_WTS(IMR_AMYOR, y);
> +		*dl++ = IMR_OP_TRI(2 * columns);
> +		/* fill single row */
> +		for (j = 0; j < columns; j++) {
> +			memcpy(dl, map, item_size);
> +			dl  += item_size / sizeof(u32);
> +			memcpy(dl, map + columns * item_size, item_size);
> +			dl  += item_size / sizeof(u32);
> +			map += item_size;
> +		}
> +	}
> +
> +	*dl++ = IMR_OP_RET;
> +	return dl;
> +}
> +
> +/*******************************************************************************
> + * Type C mapping (vertex-buffer-object)
> + ******************************************************************************/
> +
> +/* calculate length of a type C mapping */
> +static u32 imr_tri_type_c_get_length(struct imr_vbo *vbo, int item_size)
> +{
> +	return ((1 + 3 * item_size / sizeof(u32)) * vbo->num + 1) * sizeof(u32);
> +}
> +
> +/* set a VBO mapping using absolute coordinates */
> +static u32 *imr_tri_set_type_c(u32 *dl, void *map, struct imr_vbo *vbo,
> +			       int item_size)
> +{
> +	int length = 3 * item_size;
> +	int i;
> +
> +	/* prepare list of triangles to draw */
> +	for (i = 0; i < vbo->num; i++) {
> +		*dl++ = IMR_OP_TRI(3);
> +		memcpy(dl, map, length);
> +		dl  += length / sizeof(u32);
> +		map += length;
> +	}
> +
> +	*dl++ = IMR_OP_RET;
> +	return dl;
> +}
> +
> +/*******************************************************************************
> + * DL program creation
> + ******************************************************************************/
> +
> +/* return length of a DL main program */
> +static u32 imr_dl_program_length(struct imr_ctx *ctx)
> +{
> +	u32 iflags = ctx->queue[0].flags;
> +	u32 oflags = ctx->queue[1].flags;
> +	u32 cflags = __imr_flags_common(iflags, oflags);
> +
> +	/* check if formats are compatible */
> +	if (((iflags & IMR_F_PLANAR) && !(oflags & IMR_F_PLANAR)) || !cflags) {
> +		v4l2_err(&ctx->imr->v4l2_dev,
> +			 "formats are incompatible: if=%x, of=%x, cf=%x\n",
> +			 iflags, oflags, cflags);
> +		return 0;
> +	}
> +
> +	/*
> +	 * maximal possible length of the program is 27 32-bits words;
> +	 * round up to 32
> +	 */
> +	return 32 << 2;
> +}
> +
> +/* setup DL for Y/YUV planar/interleaved processing */
> +static void imr_dl_program_setup(struct imr_ctx *ctx, struct imr_cfg *cfg,
> +				 u32 type, u32 *dl, u32 subaddr)
> +{
> +	u32 iflags = ctx->queue[0].flags;
> +	u32 oflags = ctx->queue[1].flags;
> +	u32 cflags = __imr_flags_common(iflags, oflags);
> +	u16 src_y_fmt = (iflags & IMR_F_Y12 ? IMR_CMRCR_SY12 :
> +			 (iflags & IMR_F_Y10 ? IMR_CMRCR_SY10 : 0));
> +	u16 src_uv_fmt = (iflags & IMR_F_UV12 ? 2 :
> +			  (iflags & IMR_F_UV10 ? 1 : 0)) << IMR_CMRCR_SUV_SHIFT;
> +	u16 dst_y_fmt = (cflags & IMR_F_Y12 ? IMR_CMRCR_Y12 :
> +			 (cflags & IMR_F_Y10 ? IMR_CMRCR_Y10 : 0));
> +	u16 dst_uv_fmt = (cflags & IMR_F_UV12 ? 2 :
> +			  (cflags & IMR_F_UV10 ? 1 : 0)) << IMR_CMRCR_DUV_SHIFT;
> +	int w = ctx->queue[0].fmt.width;
> +	int h = ctx->queue[0].fmt.height;
> +	int W = ctx->queue[1].fmt.width;
> +	int H = ctx->queue[1].fmt.height;
> +
> +	v4l2_dbg(2, debug, &ctx->imr->v4l2_dev,
> +		 "setup %ux%u -> %ux%u mapping (type=%x)\n", w, h, W, H, type);
> +
> +	/* set triangle mode register from user-supplied descriptor */
> +	*dl++ = IMR_OP_WTS(IMR_TRIMCR, 0x004F);
> +
> +	/* set automatic source/destination coordinates generation flags */
> +	*dl++ = IMR_OP_WTS(IMR_TRIMSR, __imr_auto_sg_dg_tcm(type) |
> +			   IMR_TRIMR_BFE | IMR_TRIMR_TME);
> +
> +	/* set source/destination coordinate precision */
> +	*dl++ = IMR_OP_WTS(IMR_UVDPOR, __imr_uvdp(type));
> +
> +	/* set luminance/chromacity correction parameters precision */
> +	*dl++ = IMR_OP_WTS(IMR_CPDPOR, __imr_cpdp(type));
> +
> +	/* reset rendering mode registers */
> +	*dl++ = IMR_OP_WTS(IMR_CMRCCR,  0xDBFE);
> +	*dl++ = IMR_OP_WTS(IMR_CMRCCR2, 0x9065);
> +
> +	/* set source/destination addresses of Y/UV plane */
> +	*dl++ = IMR_OP_WTL(IMR_DSAR, 2);
> +	cfg->dst_pa_ptr[0] = dl++;
> +	cfg->src_pa_ptr[0] = dl++;
> +
> +	/* select planar/interleaved mode basing on input format */
> +	if (iflags & IMR_F_PLANAR) {
> +		/* planar input means planar output; set Y plane precision */
> +		if (cflags & IMR_F_Y8) {
> +			/*
> +			 * setup Y plane processing: YCM=0, SY/DY=xx,
> +			 * SUV/DUV=0
> +			 */
> +			*dl++ = IMR_OP_WTS(IMR_CMRCSR, src_y_fmt | src_uv_fmt |
> +					   dst_y_fmt | dst_uv_fmt |
> +					   __imr_luce(type));
> +
> +			/*
> +			 * set source/destination strides basing on Y plane
> +			 * precision
> +			 */
> +			*dl++ = IMR_OP_WTS(IMR_DSTR,
> +					   W << (cflags & IMR_F_Y10 ? 1 : 0));
> +			*dl++ = IMR_OP_WTS(IMR_SSTR,
> +					   w << (iflags & IMR_F_Y10 ? 1 : 0));
> +		} else {
> +			/* setup UV plane processing only */
> +			*dl++ = IMR_OP_WTS(IMR_CMRCSR, IMR_CMRCR_YCM |
> +					   src_uv_fmt | dst_uv_fmt |
> +					   __imr_clce(type));
> +
> +			/*
> +			 * set source/destination strides basing on UV plane
> +			 * precision
> +			 */
> +			*dl++ = IMR_OP_WTS(IMR_DSTR,
> +					   W << (cflags & IMR_F_UV10 ? 1 : 0));
> +			*dl++ = IMR_OP_WTS(IMR_SSTR,
> +					   w << (iflags & IMR_F_UV10 ? 1 : 0));
> +		}
> +	} else {
> +		u16 src_fmt = (iflags & IMR_F_UV_SWAP ? IMR_CMRCR2_UVFORM : 0) |
> +			      (iflags & IMR_F_YUV_SWAP ?
> +			       IMR_CMRCR2_YUV422FORM : 0);
> +		u32 dst_fmt = (oflags & IMR_F_YUV_SWAP ? IMR_TRICR_YCFORM : 0);
> +
> +		/* interleaved input; output is either interleaved or planar */
> +		*dl++ = IMR_OP_WTS(IMR_CMRCSR2, IMR_CMRCR2_YUV422E | src_fmt);
> +
> +		/* destination is always YUYV or UYVY */
> +		*dl++ = IMR_OP_WTL(IMR_TRICR, 1);
> +		*dl++ = dst_fmt;
> +
> +		/* set precision of Y/UV planes and required correction */
> +		*dl++ = IMR_OP_WTS(IMR_CMRCSR, src_y_fmt | src_uv_fmt |
> +				   dst_y_fmt | dst_uv_fmt | __imr_clce(type) |
> +				   __imr_luce(type));
> +
> +		/* set source stride basing on precision (2 or 4 bytes/pixel) */
> +		*dl++ = IMR_OP_WTS(IMR_SSTR, w << (iflags & IMR_F_Y10 ? 2 : 1));
> +
> +		/* if output is planar, put the offset value */
> +		if (oflags & IMR_F_PLANAR) {
> +			/* specify offset of a destination UV plane */
> +			*dl++ = IMR_OP_WTL(IMR_DSOR, 1);
> +			*dl++ = W * H;
> +
> +			/*
> +			 * destination stride is 1 or 2 bytes/pixel
> +			 * (same for both Y and UV planes)
> +			 */
> +			*dl++ = IMR_OP_WTS(IMR_DSTR,
> +					   W << (cflags & IMR_F_Y10 ? 1 : 0));
> +		} else {
> +			/*
> +			 * destination stride if 2 or 4 bytes/pixel
> +			 * (Y and UV planes interleaved)
> +			 */
> +			*dl++ = IMR_OP_WTS(IMR_DSTR,
> +					   W << (cflags & IMR_F_Y10 ? 2 : 1));
> +		}
> +	}
> +
> +	/*
> +	 * set source width/height of Y/UV plane
> +	 * (for Y plane upper part of SUSR is ignored)
> +	 */
> +	*dl++ = IMR_OP_WTL(IMR_SUSR, 2);
> +	*dl++ = ((w - 2) << IMR_SUSR_SUW_SHIFT) |
> +		((w - 1) << IMR_SUSR_SVW_SHIFT);
> +	*dl++ = h - 1;
> +
> +	/* invoke subroutine for drawing triangles */
> +	*dl++ = IMR_OP_GOSUB;
> +	*dl++ = subaddr;
> +
> +	/* if we have a planar output with both Y and UV planes available */
> +	if ((cflags & (IMR_F_PLANAR | IMR_F_Y8 | IMR_F_UV8)) ==
> +	    (IMR_F_PLANAR | IMR_F_Y8 | IMR_F_UV8)) {
> +		/* select UV plane processing mode; put sync before switching */
> +		*dl++ = IMR_OP_SYNCM;
> +
> +		/* setup UV-plane source/destination addresses */
> +		*dl++ = IMR_OP_WTL(IMR_DSAR, 2);
> +		cfg->dst_pa_ptr[1] = dl++;
> +		cfg->src_pa_ptr[1] = dl++;
> +
> +		/* select correction mode */
> +		*dl++ = IMR_OP_WTS(IMR_CMRCSR, IMR_CMRCR_YCM |
> +				   __imr_clce(type));
> +
> +		/* luminance correction bit must be cleared (if it was set) */
> +		*dl++ = IMR_OP_WTS(IMR_CMRCCR, IMR_CMRCR_LUCE);
> +
> +		/* draw triangles */
> +		*dl++ = IMR_OP_GOSUB;
> +		*dl++ = subaddr;
> +	} else {
> +		/*
> +		 * clear pointers to the source/destination UV-planes addresses
> +		 */
> +		cfg->src_pa_ptr[1] = cfg->dst_pa_ptr[1] = NULL;
> +	}
> +
> +	/* signal completion of the operation */
> +	*dl++ = IMR_OP_SYNCM;
> +	*dl++ = IMR_OP_TRAP;
> +}
> +
> +/*******************************************************************************
> + * Mapping specification processing
> + ******************************************************************************/
> +
> +/* set mapping data (function called with video device lock held) */
> +static int imr_ioctl_map(struct imr_ctx *ctx, struct imr_map_desc *desc)
> +{
> +	struct imr_device	*imr = ctx->imr;
> +	struct imr_mesh		*mesh;
> +	struct imr_vbo		*vbo;
> +	struct imr_cfg		*cfg;
> +	void			*buf, *map;
> +	u32                     type;
> +	u32			length, item_size;
> +	u32			tri_length;
> +	void			*dl_vaddr;
> +	u32			dl_size;
> +	u32			dl_start_offset;
> +	dma_addr_t		dl_dma_addr;
> +	int			ret = 0;
> +
> +	/* read remainder of data into temporary buffer */
> +	length = desc->size;
> +	buf  = memdup_user((void __user *)(unsigned long)desc->data, length);
> +	if (IS_ERR(buf)) {
> +		v4l2_err(&imr->v4l2_dev,
> +			 "failed to copy %u bytes of mapping specification\n",
> +			 length);
> +		return PTR_ERR(buf);
> +	}
> +
> +	/* mesh item size calculation */
> +	type = desc->type;
> +	item_size = (type & IMR_MAP_LUCE ? 4 : 0) +
> +		    (type & IMR_MAP_CLCE ? 4 : 0);
> +
> +	/* calculate the length of a display list */
> +	if (type & IMR_MAP_MESH) {
> +		/* assure we have proper mesh descriptor */
> +		if (length < sizeof(struct imr_mesh)) {
> +			v4l2_err(&imr->v4l2_dev,
> +				 "invalid mesh specification size: %u\n",
> +				 length);
> +			ret = -EINVAL;
> +			goto out;
> +		}
> +
> +		mesh = (struct imr_mesh *)buf;
> +		length -= sizeof(struct imr_mesh);
> +		map = buf + sizeof(struct imr_mesh);
> +
> +		if (type & (IMR_MAP_AUTODG | IMR_MAP_AUTOSG)) {
> +			/*
> +			 * mapping is given using automatic generation pattern;
> +			 * source/destination vertex size is 4 bytes
> +			 */
> +			item_size += 4;
> +
> +			/* calculate size of triangles drawing subroutine */
> +			tri_length = imr_tri_type_b_get_length(mesh, item_size);
> +		} else {
> +			/*
> +			 * mapping is done with absolute coordinates;
> +			 * source/destination vertex size is 8 bytes
> +			 */
> +			item_size += 8;
> +
> +			/* calculate size of triangles drawing subroutine */
> +			tri_length = imr_tri_type_a_get_length(mesh, item_size);
> +		}
> +
> +		/* check size */
> +		if (mesh->rows * mesh->columns * item_size != length) {
> +			v4l2_err(&imr->v4l2_dev,
> +				 "invalid mesh size: %u*%u*%u != %u\n",
> +				 mesh->rows, mesh->columns, item_size,
> +				 length);
> +			ret = -EINVAL;
> +			goto out;
> +		}
> +	} else {
> +		/* assure we have proper VBO descriptor */
> +		if (length < sizeof(struct imr_vbo)) {
> +			v4l2_err(&imr->v4l2_dev,
> +				 "invalid vbo specification size: %u\n",
> +				 length);
> +			ret = -EINVAL;
> +			goto out;
> +		}
> +
> +		/* make sure there is no automatically generation flags */
> +		if (type & (IMR_MAP_AUTODG | IMR_MAP_AUTOSG)) {
> +			v4l2_err(&imr->v4l2_dev,
> +				 "invalid auto-dg/sg flags: 0x%x\n", type);
> +			ret = -EINVAL;
> +			goto out;
> +		}
> +
> +		vbo = (struct imr_vbo *)buf;
> +		length -= sizeof(struct imr_vbo);
> +		map = buf + sizeof(struct imr_vbo);
> +
> +		/* vertex is given with absolute coordinates */
> +		item_size += 8;
> +
> +		/* check that the length is sane */
> +		if (vbo->num * 3 * item_size != length) {
> +			v4l2_err(&imr->v4l2_dev,
> +				 "invalid vbo size: %u*%u*3 != %u\n", vbo->num,
> +				 item_size, length);
> +			ret = -EINVAL;
> +			goto out;
> +		}
> +
> +		/* calculate size of triangles drawing subroutine */
> +		tri_length = imr_tri_type_c_get_length(vbo, item_size);
> +	}
> +
> +	/* DL main program shall start on 8-byte aligned address */
> +	dl_start_offset = ALIGN(tri_length, 8);
> +
> +	/* calculate main routine length */
> +	dl_size = imr_dl_program_length(ctx);
> +	if (!dl_size) {
> +		v4l2_err(&imr->v4l2_dev, "format configuration error\n");
> +		ret = -EINVAL;
> +		goto out;
> +	}
> +
> +	/* we use a single display list, with TRI subroutine prepending MAIN */
> +	dl_size += dl_start_offset;
> +
> +	/* unref current configuration (will not be used by subsequent jobs) */
> +	imr_cfg_unref(ctx, ctx->cfg);
> +
> +	/* create new configuration */
> +	cfg = imr_cfg_create(ctx, dl_size, dl_start_offset);
> +	if (IS_ERR(cfg)) {
> +		ret = PTR_ERR(cfg);
> +		ctx->cfg = NULL;
> +		v4l2_err(&imr->v4l2_dev,
> +			 "failed to create configuration: %d\n", ret);
> +		goto out;
> +	}
> +	ctx->cfg = cfg;
> +
> +	/* get pointer to the new display list */
> +	dl_vaddr = cfg->dl_vaddr;
> +	dl_dma_addr = cfg->dl_dma_addr;
> +
> +	/* prepare a triangles drawing subroutine */
> +	if (type & IMR_MAP_MESH) {
> +		if (type & (IMR_MAP_AUTOSG | IMR_MAP_AUTODG))
> +			imr_tri_set_type_b(dl_vaddr, map, mesh, item_size);
> +		else
> +			imr_tri_set_type_a(dl_vaddr, map, mesh, item_size);
> +	} else {
> +		imr_tri_set_type_c(dl_vaddr, map, vbo, item_size);
> +	}
> +
> +	/* prepare main DL program */
> +	imr_dl_program_setup(ctx, cfg, type, dl_vaddr + dl_start_offset,
> +			     (u32)dl_dma_addr);
> +
> +	/* update cropping parameters */
> +	cfg->dst_subpixel = (type & IMR_MAP_DDP ? 2 : 0);
> +
> +	/* display list updated successfully */
> +	v4l2_dbg(2, debug, &ctx->imr->v4l2_dev,
> +		 "display-list created: #%u[%08X]:%u[%u]\n",
> +		 cfg->id, (u32)dl_dma_addr, dl_size, dl_start_offset);
> +
> +	if (debug >= 4)
> +		print_hex_dump_bytes("DL-", DUMP_PREFIX_OFFSET,
> +				     dl_vaddr + dl_start_offset,
> +				     dl_size  - dl_start_offset);
> +
> +out:
> +	/* release interim buffer */
> +	kfree(buf);
> +
> +	return ret;
> +}
> +
> +/*******************************************************************************
> + * V4L2 I/O controls
> + ******************************************************************************/
> +
> +/* test if a format is supported */
> +static int __imr_try_fmt(struct imr_ctx *ctx, struct v4l2_format *f)
> +{
> +	struct v4l2_pix_format	*pix = &f->fmt.pix;
> +	u32			fourcc = pix->pixelformat;
> +	int			i;
> +
> +	/*
> +	 * both output and capture interface have the same set of
> +	 * supported formats
> +	 */
> +	for (i = 0; i < ARRAY_SIZE(imr_lx4_formats); i++) {
> +		if (fourcc == imr_lx4_formats[i].fourcc) {
> +			/* fix up format specification as needed */
> +			pix->field = V4L2_FIELD_NONE;
> +
> +			v4l2_dbg(1, debug, &ctx->imr->v4l2_dev,
> +				 "format request: '%c%c%c%c', %dx%d\n",
> +				 (fourcc >> 0)	& 0xff,	(fourcc >> 8)  & 0xff,
> +				 (fourcc >> 16) & 0xff, (fourcc >> 24) & 0xff,
> +				 pix->width, pix->height);
> +
> +			/* verify source/destination image dimensions */
> +			if (V4L2_TYPE_IS_OUTPUT(f->type))
> +				v4l_bound_align_image(&pix->width, 128, 2048, 7,
> +						      &pix->height,  1, 2048, 0,
> +						      0);
> +			else
> +				v4l_bound_align_image(&pix->width,  64, 2048, 6,
> +						      &pix->height,  1, 2048, 0,
> +						      0);
> +
> +			return i;
> +		}
> +	}
> +
> +	v4l2_err(&ctx->imr->v4l2_dev,
> +		 "unsupported format request: '%c%c%c%c'\n",
> +		 (fourcc >> 0)  & 0xff, (fourcc >> 8)  & 0xff,
> +		 (fourcc >> 16) & 0xff, (fourcc >> 24) & 0xff);
> +
> +	return -EINVAL;
> +}
> +
> +/* capabilities query */
> +static int imr_querycap(struct file *file, void *priv,
> +			struct v4l2_capability *cap)
> +{
> +	strlcpy(cap->driver, DRV_NAME, sizeof(cap->driver));
> +	strlcpy(cap->card, DRV_NAME, sizeof(cap->card));
> +	strlcpy(cap->bus_info, DRV_NAME, sizeof(cap->bus_info));
> +
> +	return 0;
> +}
> +
> +/* enumerate supported formats */
> +static int imr_enum_fmt(struct file *file, void *priv, struct v4l2_fmtdesc *f)
> +{
> +	/* no distinction between output/capture formats */
> +	if (f->index < ARRAY_SIZE(imr_lx4_formats)) {
> +		f->pixelformat = imr_lx4_formats[f->index].fourcc;
> +		return 0;
> +	}
> +
> +	return -EINVAL;
> +}
> +
> +/* retrieve current queue format; operation is locked? */
> +static int imr_g_fmt(struct file *file, void *priv, struct v4l2_format *f)
> +{
> +	struct imr_ctx		*ctx = fh_to_ctx(priv);
> +	struct imr_q_data	*q_data;
> +	struct vb2_queue	*vq;
> +
> +	vq = v4l2_m2m_get_vq(ctx->m2m_ctx, f->type);
> +	if (!vq)
> +		return -EINVAL;
> +
> +	q_data = &ctx->queue[V4L2_TYPE_IS_OUTPUT(f->type) ? 0 : 1];
> +
> +	/* processing is locked? TBD */
> +	f->fmt.pix = q_data->fmt;
> +
> +	return 0;
> +}
> +
> +/* test particular format; operation is not locked */
> +static int imr_try_fmt(struct file *file, void *priv, struct v4l2_format *f)
> +{
> +	struct imr_ctx		*ctx = fh_to_ctx(priv);
> +	struct vb2_queue	*vq;
> +
> +	/* make sure we have a queue of particular type */
> +	vq = v4l2_m2m_get_vq(ctx->m2m_ctx, f->type);
> +	if (!vq)
> +		return -EINVAL;
> +
> +	/* test if format is supported (adjust as appropriate) */
> +	return __imr_try_fmt(ctx, f) >= 0 ? 0 : -EINVAL;
> +}
> +
> +/* apply queue format; operation is locked? */
> +static int imr_s_fmt(struct file *file, void *priv, struct v4l2_format *f)
> +{
> +	struct imr_ctx		*ctx = fh_to_ctx(priv);
> +	struct imr_q_data	*q_data;
> +	struct vb2_queue	*vq;
> +	int			i;
> +
> +	vq = v4l2_m2m_get_vq(ctx->m2m_ctx, f->type);
> +	if (!vq)
> +		return -EINVAL;
> +
> +	/* check if queue is busy */
> +	if (vb2_is_busy(vq))
> +		return -EBUSY;
> +
> +	/* test if format is supported (adjust as appropriate) */
> +	i = __imr_try_fmt(ctx, f);
> +	if (i < 0)
> +		return -EINVAL;
> +
> +	/* format is supported; save current format in a queue-specific data */
> +	q_data = &ctx->queue[V4L2_TYPE_IS_OUTPUT(f->type) ? 0 : 1];
> +
> +	/* processing is locked? TBD */
> +	q_data->fmt = f->fmt.pix;
> +	q_data->flags = imr_lx4_formats[i].flags;
> +
> +	/* set default compose factors */
> +	if (!V4L2_TYPE_IS_OUTPUT(f->type)) {
> +		ctx->rect.min.x = 0;
> +		ctx->rect.min.y = f->fmt.pix.width - 1;
> +		ctx->rect.max.x = 0;
> +		ctx->rect.max.y = f->fmt.pix.height - 1;
> +	}
> +
> +	return 0;
> +}
> +
> +static int imr_qbuf(struct file *file, void *priv, struct v4l2_buffer *buf)
> +{
> +	struct imr_ctx *ctx = fh_to_ctx(priv);
> +
> +	/* operation is protected with a queue lock */
> +	WARN_ON(!mutex_is_locked(&ctx->imr->mutex));

It's guaranteed by the V4L2 core, so this can be dropped safely.

> +
> +	/* verify the configuration is complete */
> +	if (!ctx->cfg) {
> +		v4l2_err(&ctx->imr->v4l2_dev,
> +			 "stream configuration is not complete\n");
> +		return -EINVAL;
> +	}

Shouldn't this test be done in the buf_prepare callback above? It's
what buf_prepare is for.

Then you can drop this function and use the helper function instead.

> +
> +	return v4l2_m2m_qbuf(file, ctx->m2m_ctx, buf);
> +}
> +
> +static int imr_g_selection(struct file *file, void *priv,
> +			   struct v4l2_selection *s)
> +{
> +	struct imr_ctx		*ctx = fh_to_ctx(priv);
> +	struct imr_q_data	*q_data = &ctx->queue[1];
> +
> +	if (s->type != V4L2_BUF_TYPE_VIDEO_CAPTURE)
> +		return -EINVAL;
> +
> +	switch (s->target) {
> +	case V4L2_SEL_TGT_COMPOSE_BOUNDS:
> +	case V4L2_SEL_TGT_COMPOSE_DEFAULT:
> +		s->r.left = s->r.top = 0;
> +		s->r.width  = q_data->fmt.width;
> +		s->r.height = q_data->fmt.height;
> +		break;
> +	case V4L2_SEL_TGT_COMPOSE:
> +		s->r.left = ctx->rect.min.x;
> +		s->r.top  = ctx->rect.min.y;
> +		s->r.width  = ctx->rect.max.x - ctx->rect.min.x + 1;
> +		s->r.height = ctx->rect.max.y - ctx->rect.min.y + 1;
> +		break;
> +	default:
> +		return -EINVAL;
> +	}
> +
> +	return 0;
> +}
> +
> +static int imr_s_selection(struct file *file, void *priv,
> +			   struct v4l2_selection *s)
> +{
> +	struct imr_ctx	*ctx = fh_to_ctx(priv);
> +	struct imr_q_data *q_data = &ctx->queue[1];
> +	struct v4l2_rect r = s->r;
> +	struct v4l2_rect max_rect;
> +
> +	if (s->type != V4L2_BUF_TYPE_VIDEO_CAPTURE)
> +		return -EINVAL;
> +
> +	switch (s->target) {
> +	case V4L2_SEL_TGT_COMPOSE:
> +		/* Make sure compose rect fits inside output format */
> +		max_rect.top = max_rect.left = 0;
> +		max_rect.width  = q_data->fmt.width;
> +		max_rect.height = q_data->fmt.height;
> +		v4l2_rect_map_inside(&r, &max_rect);
> +
> +		/* subpixel resolution of output buffer is not counted here */
> +		ctx->rect.min.x = r.left;
> +		ctx->rect.min.y = r.top;
> +		ctx->rect.max.x = r.left + r.width  - 1;
> +		ctx->rect.max.y = r.top  + r.height - 1;
> +
> +		s->r = r;
> +		return 0;
> +	default:
> +		return -EINVAL;
> +	}
> +}
> +
> +/* customized I/O control processing */
> +static long imr_default(struct file *file, void *fh, bool valid_prio,
> +			unsigned int cmd,  void *arg)
> +{
> +	struct imr_ctx *ctx = fh_to_ctx(fh);
> +
> +	switch (cmd) {
> +	case VIDIOC_IMR_MESH:
> +		/* set mesh data */
> +		return imr_ioctl_map(ctx, arg);
> +
> +	default:
> +		return -ENOTTY;
> +	}
> +}
> +
> +static const struct v4l2_ioctl_ops imr_ioctl_ops = {
> +	.vidioc_querycap		= imr_querycap,
> +
> +	.vidioc_enum_fmt_vid_cap	= imr_enum_fmt,
> +	.vidioc_enum_fmt_vid_out	= imr_enum_fmt,
> +	.vidioc_g_fmt_vid_cap		= imr_g_fmt,
> +	.vidioc_g_fmt_vid_out		= imr_g_fmt,
> +	.vidioc_try_fmt_vid_cap		= imr_try_fmt,
> +	.vidioc_try_fmt_vid_out		= imr_try_fmt,
> +	.vidioc_s_fmt_vid_cap		= imr_s_fmt,
> +	.vidioc_s_fmt_vid_out		= imr_s_fmt,
> +
> +	.vidioc_reqbufs			= v4l2_m2m_ioctl_reqbufs,
> +	.vidioc_create_bufs		= v4l2_m2m_ioctl_create_bufs,
> +	.vidioc_querybuf		= v4l2_m2m_ioctl_querybuf,
> +	.vidioc_qbuf			= imr_qbuf,
> +	.vidioc_dqbuf			= v4l2_m2m_ioctl_dqbuf,
> +	.vidioc_prepare_buf		= v4l2_m2m_ioctl_prepare_buf,
> +	.vidioc_expbuf			= v4l2_m2m_ioctl_expbuf,
> +	.vidioc_streamon		= v4l2_m2m_ioctl_streamon,
> +	.vidioc_streamoff		= v4l2_m2m_ioctl_streamoff,
> +
> +	.vidioc_g_selection		= imr_g_selection,
> +	.vidioc_s_selection		= imr_s_selection,
> +
> +	.vidioc_default			= imr_default,
> +};
> +
> +/*******************************************************************************
> + * Generic device file operations
> + ******************************************************************************/
> +
> +static int imr_open(struct file *file)
> +{
> +	struct imr_device	*imr = video_drvdata(file);
> +	struct video_device	*vfd = video_devdata(file);
> +	struct imr_ctx		*ctx;
> +	int			ret;
> +
> +	/* allocate processing context associated with given instance */
> +	ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
> +	if (!ctx)
> +		return -ENOMEM;
> +
> +	/* initialize per-file-handle structure */
> +	v4l2_fh_init(&ctx->fh, vfd);
> +	file->private_data = &ctx->fh;
> +	v4l2_fh_add(&ctx->fh);
> +
> +	/* set default source/destination formats - need that? */
> +	ctx->imr = imr;
> +	ctx->queue[0].fmt.pixelformat = V4L2_PIX_FMT_UYVY;
> +	ctx->queue[1].fmt.pixelformat = V4L2_PIX_FMT_UYVY;
> +
> +	/* set default cropping parameters */
> +	ctx->rect.max.x = ctx->rect.max.y = 0x3FF;
> +
> +	/* initialize M2M processing context */
> +	ctx->m2m_ctx = v4l2_m2m_ctx_init(imr->m2m_dev, ctx, imr_queue_init);
> +	if (IS_ERR(ctx->m2m_ctx)) {
> +		ret = PTR_ERR(ctx->m2m_ctx);
> +		goto v4l_prepare_rollback;
> +	}
> +
> +	/* lock access to global device data */
> +	if (mutex_lock_interruptible(&imr->mutex)) {
> +		ret = -ERESTARTSYS;
> +		goto v4l_prepare_rollback;
> +	}
> +
> +	/* bring up device as needed */
> +	if (imr->refcount == 0) {
> +		ret = clk_prepare_enable(imr->clock);
> +		if (ret < 0)
> +			goto device_prepare_rollback;
> +	}
> +
> +	imr->refcount++;
> +
> +	mutex_unlock(&imr->mutex);
> +
> +	v4l2_dbg(1, debug, &imr->v4l2_dev, "IMR device opened (refcount=%u)\n",
> +		 imr->refcount);
> +
> +	return 0;
> +
> +device_prepare_rollback:
> +	/* unlock global device data */
> +	mutex_unlock(&imr->mutex);
> +
> +v4l_prepare_rollback:
> +	/* destroy context */
> +	v4l2_fh_del(&ctx->fh);
> +	v4l2_fh_exit(&ctx->fh);
> +	kfree(ctx);
> +
> +	return ret;
> +}
> +
> +static int imr_release(struct file *file)
> +{
> +	struct imr_ctx		*ctx = fh_to_ctx(file->private_data);
> +	struct imr_device	*imr = video_drvdata(file);
> +
> +	/* I don't need to get a device scope lock here really - TBD */
> +	mutex_lock(&imr->mutex);
> +
> +	/* destroy M2M device processing context */
> +	v4l2_m2m_ctx_release(ctx->m2m_ctx);
> +	v4l2_fh_del(&ctx->fh);
> +	v4l2_fh_exit(&ctx->fh);
> +
> +	/* drop active configuration as needed */
> +	imr_cfg_unref(ctx, ctx->cfg);
> +
> +	/* make sure there are no more active configs */
> +	WARN_ON(ctx->cfg_num);
> +
> +	/* destroy context data */
> +	kfree(ctx);
> +
> +	/* disable hardware operation */
> +	if (--imr->refcount == 0)
> +		clk_disable_unprepare(imr->clock);
> +
> +	mutex_unlock(&imr->mutex);
> +
> +	v4l2_dbg(1, debug, &imr->v4l2_dev, "closed device instance\n");
> +
> +	return 0;
> +}
> +
> +static unsigned int imr_poll(struct file *file, struct poll_table_struct *wait)
> +{
> +	struct imr_ctx		*ctx = fh_to_ctx(file->private_data);
> +	struct imr_device	*imr = video_drvdata(file);
> +	unsigned int		res;
> +
> +	if (mutex_lock_interruptible(&imr->mutex))
> +		return -ERESTARTSYS;
> +
> +	res = v4l2_m2m_poll(file, ctx->m2m_ctx, wait);
> +	mutex_unlock(&imr->mutex);
> +
> +	return res;
> +}

Set the struct v4l2_m2m_ctx q_lock field to imr->mutex.

Then you can use v4l2_m2m_fop_poll instead.

> +
> +static int imr_mmap(struct file *file, struct vm_area_struct *vma)
> +{
> +	struct imr_device	*imr = video_drvdata(file);
> +	struct imr_ctx		*ctx = fh_to_ctx(file->private_data);
> +	int			ret;
> +
> +	/* should we protect all M2M operations with mutex? - TBD */
> +	if (mutex_lock_interruptible(&imr->mutex))
> +		return -ERESTARTSYS;
> +
> +	ret = v4l2_m2m_mmap(file, ctx->m2m_ctx, vma);
> +
> +	mutex_unlock(&imr->mutex);
> +
> +	return ret;
> +}

Use v4l2_m2m_fop_mmap. And this is one file operation where you shouldn't lock.
The vb2 core has a special mutex to handle this.

> +
> +static const struct v4l2_file_operations imr_fops = {
> +	.owner		= THIS_MODULE,
> +	.open		= imr_open,
> +	.release	= imr_release,
> +	.poll		= imr_poll,
> +	.mmap		= imr_mmap,
> +	.unlocked_ioctl	= video_ioctl2,
> +};
> +
> +/*******************************************************************************
> + * M2M device interface
> + ******************************************************************************/
> +
> +/* job execution function */
> +static void imr_device_run(void *priv)
> +{
> +	struct imr_ctx		*ctx = priv;
> +	struct imr_device	*imr = ctx->imr;
> +	struct vb2_buffer	*src_buf, *dst_buf;
> +	u32			src_addr,  dst_addr;
> +	unsigned long		flags;
> +	struct imr_cfg		*cfg;
> +
> +	v4l2_dbg(3, debug, &imr->v4l2_dev, "run next job...\n");
> +
> +	/* protect access to internal device state */
> +	spin_lock_irqsave(&imr->lock, flags);
> +
> +	/* retrieve input/output buffers */
> +	src_buf = v4l2_m2m_next_src_buf(ctx->m2m_ctx);
> +	dst_buf = v4l2_m2m_next_dst_buf(ctx->m2m_ctx);
> +
> +	/* take configuration pointer associated with input buffer */
> +	cfg = to_imr_buffer(to_vb2_v4l2_buffer(src_buf))->cfg;
> +
> +	/* cancel software reset state as needed */
> +	iowrite32(0, imr->mmio + IMR_CR);
> +
> +	/* set composing data with respect to destination subpixel mode */
> +	iowrite32(ctx->rect.min.x << cfg->dst_subpixel, imr->mmio + IMR_XMINR);
> +	iowrite32(ctx->rect.min.y << cfg->dst_subpixel, imr->mmio + IMR_YMINR);
> +	iowrite32(ctx->rect.max.x << cfg->dst_subpixel, imr->mmio + IMR_XMAXR);
> +	iowrite32(ctx->rect.max.y << cfg->dst_subpixel, imr->mmio + IMR_YMAXR);
> +
> +	/*
> +	 * adjust source/destination parameters of the program
> +	 * (interleaved/semiplanar)
> +	 */
> +	*cfg->src_pa_ptr[0] = src_addr =
> +		(u32)vb2_dma_contig_plane_dma_addr(src_buf, 0);
> +	*cfg->dst_pa_ptr[0] = dst_addr =
> +		(u32)vb2_dma_contig_plane_dma_addr(dst_buf, 0);
> +
> +	/* adjust source/destination parameters of the UV plane as needed */
> +	if (cfg->src_pa_ptr[1] && cfg->dst_pa_ptr[1]) {
> +		*cfg->src_pa_ptr[1] = src_addr +
> +			ctx->queue[0].fmt.width * ctx->queue[0].fmt.height;
> +		*cfg->dst_pa_ptr[1] = dst_addr +
> +			ctx->queue[1].fmt.width * ctx->queue[1].fmt.height;
> +	}
> +
> +	v4l2_dbg(3, debug, &imr->v4l2_dev,
> +		 "process buffer-pair 0x%08x:0x%08x\n",
> +		 *cfg->src_pa_ptr[0], *cfg->dst_pa_ptr[0]);
> +
> +	/* force clearing of the status register bits */
> +	iowrite32(IMR_SR_TRA | IMR_SR_IER | IMR_SR_INT, imr->mmio + IMR_SRCR);
> +
> +	/* unmask/enable interrupts */
> +	iowrite32(ioread32(imr->mmio + IMR_ICR) |
> +		  (IMR_ICR_TRAENB | IMR_ICR_IERENB | IMR_ICR_INTENB),
> +		  imr->mmio + IMR_ICR);
> +	iowrite32(ioread32(imr->mmio + IMR_IMR) &
> +		  ~(IMR_IMR_TRAM | IMR_IMR_IEM | IMR_IMR_INM),
> +		  imr->mmio + IMR_IMR);
> +
> +	/* set display list address */
> +	iowrite32(cfg->dl_dma_addr + cfg->dl_start_offset,
> +		  imr->mmio + IMR_DLSAR);
> +
> +	/*
> +	 * explicitly flush any pending write operations
> +	 * (don't need that, I guess)
> +	 */
> +	wmb();
> +
> +	/* start rendering operation */
> +	iowrite32(IMR_CR_RS, imr->mmio + IMR_CR);
> +
> +	/* timestamp input buffer */
> +	src_buf->timestamp = ktime_get_ns();
> +
> +	/* unlock device access */
> +	spin_unlock_irqrestore(&imr->lock, flags);
> +
> +	v4l2_dbg(1, debug, &imr->v4l2_dev,
> +		 "rendering started: status=%x, DLSAR=0x%08x, DLPR=0x%08x\n",
> +		 ioread32(imr->mmio + IMR_SR), ioread32(imr->mmio + IMR_DLSAR),
> +		 ioread32(imr->mmio + IMR_DLPR));
> +}
> +
> +/* check whether a job is ready for execution */
> +static int imr_job_ready(void *priv)
> +{
> +	/* no specific requirements on the job readiness */
> +	return 1;
> +}
> +
> +/* abort currently processed job */
> +static void imr_job_abort(void *priv)
> +{
> +	struct imr_ctx		*ctx = priv;
> +	struct imr_device	*imr = ctx->imr;
> +	unsigned long		flags;
> +
> +	/* protect access to internal device state */
> +	spin_lock_irqsave(&imr->lock, flags);
> +
> +	/*
> +	 * make sure current job is still current
> +	 * (may get finished by interrupt already)
> +	 */
> +	if (v4l2_m2m_get_curr_priv(imr->m2m_dev) == ctx) {
> +		v4l2_dbg(1, debug, &imr->v4l2_dev,
> +			 "abort job: status=%x, DLSAR=0x%08x, DLPR=0x%08x\n",
> +			 ioread32(imr->mmio + IMR_SR),
> +			 ioread32(imr->mmio + IMR_DLSAR),
> +			 ioread32(imr->mmio + IMR_DLPR));
> +
> +		/*
> +		 * resetting the module while operation is active may lead to
> +		 * h/w stall
> +		 */
> +		spin_unlock_irqrestore(&imr->lock, flags);
> +	} else {
> +		spin_unlock_irqrestore(&imr->lock, flags);
> +		v4l2_dbg(1, debug, &imr->v4l2_dev,
> +			 "job has completed already\n");
> +	}
> +}
> +
> +/* M2M interface definition */
> +static struct v4l2_m2m_ops imr_m2m_ops = {
> +	.device_run	= imr_device_run,
> +	.job_ready	= imr_job_ready,
> +	.job_abort	= imr_job_abort,
> +};
> +
> +/*******************************************************************************
> + * Interrupt handling
> + ******************************************************************************/
> +
> +static irqreturn_t imr_irq_handler(int irq, void *data)
> +{
> +	struct imr_device	*imr = data;
> +	struct vb2_v4l2_buffer	*src_buf, *dst_buf;
> +	bool			finish = false;
> +	u32			status;
> +	struct imr_ctx		*ctx;
> +
> +	/* check and ack interrupt status */
> +	status = ioread32(imr->mmio + IMR_SR);
> +	iowrite32(status, imr->mmio + IMR_SRCR);
> +	if (!(status & (IMR_SR_INT | IMR_SR_IER | IMR_SR_TRA))) {
> +		v4l2_err(&imr->v4l2_dev, "spurious interrupt: %x\n", status);
> +		return IRQ_NONE;
> +	}
> +
> +	/* protect access to current context */
> +	spin_lock(&imr->lock);
> +
> +	/* get current job context (may have been cancelled already) */
> +	ctx = v4l2_m2m_get_curr_priv(imr->m2m_dev);
> +	if (!ctx) {
> +		v4l2_dbg(3, debug, &imr->v4l2_dev, "no active job\n");
> +		goto handled;
> +	}
> +
> +	/* remove buffers (may have been removed already?) */
> +	src_buf = v4l2_m2m_src_buf_remove(ctx->m2m_ctx);
> +	dst_buf = v4l2_m2m_dst_buf_remove(ctx->m2m_ctx);
> +	if (!src_buf || !dst_buf) {
> +		v4l2_dbg(3, debug, &imr->v4l2_dev,
> +			 "no buffers associated with current context\n");
> +		goto handled;
> +	}
> +
> +	finish = true;
> +
> +	/* check for a TRAP interrupt indicating completion of current DL */
> +	if (status & IMR_SR_TRA) {
> +		/* operation completed normally; timestamp output buffer */
> +		dst_buf->vb2_buf.timestamp = ktime_get_ns();
> +		if (src_buf->flags & V4L2_BUF_FLAG_TIMECODE)
> +			dst_buf->timecode = src_buf->timecode;
> +		dst_buf->flags = src_buf->flags &
> +			(V4L2_BUF_FLAG_TIMECODE | V4L2_BUF_FLAG_KEYFRAME |
> +			 V4L2_BUF_FLAG_PFRAME | V4L2_BUF_FLAG_BFRAME |
> +			 V4L2_BUF_FLAG_TSTAMP_SRC_MASK);
> +		dst_buf->sequence = src_buf->sequence = ctx->sequence++;
> +		v4l2_m2m_buf_done(src_buf, VB2_BUF_STATE_DONE);
> +		v4l2_m2m_buf_done(dst_buf, VB2_BUF_STATE_DONE);
> +
> +		v4l2_dbg(3, debug, &imr->v4l2_dev,
> +			 "buffers <0x%08x,0x%08x> done\n",
> +			(u32)vb2_dma_contig_plane_dma_addr
> +				(&src_buf->vb2_buf, 0),
> +			(u32)vb2_dma_contig_plane_dma_addr
> +				(&dst_buf->vb2_buf, 0));
> +	} else {
> +		/*
> +		 * operation completed in error; no way to understand
> +		 * what exactly went wrong
> +		 */
> +		v4l2_m2m_buf_done(src_buf, VB2_BUF_STATE_ERROR);
> +		v4l2_m2m_buf_done(dst_buf, VB2_BUF_STATE_ERROR);
> +
> +		v4l2_dbg(3, debug, &imr->v4l2_dev,
> +			 "buffers <0x%08x,0x%08x> done in error\n",
> +			 (u32)vb2_dma_contig_plane_dma_addr
> +				(&src_buf->vb2_buf, 0),
> +			 (u32)vb2_dma_contig_plane_dma_addr
> +				(&dst_buf->vb2_buf, 0));
> +	}
> +
> +handled:
> +	spin_unlock(&imr->lock);
> +
> +	/* finish current job (and start any pending) */
> +	if (finish)
> +		v4l2_m2m_job_finish(imr->m2m_dev, ctx->m2m_ctx);
> +
> +	return IRQ_HANDLED;
> +}
> +
> +/*******************************************************************************
> + * Device probing/removal interface
> + ******************************************************************************/
> +
> +static int imr_probe(struct platform_device *pdev)
> +{
> +	struct imr_device	*imr;
> +	struct resource		*res;
> +	int			ret;
> +
> +	imr = devm_kzalloc(&pdev->dev, sizeof(*imr), GFP_KERNEL);
> +	if (!imr)
> +		return -ENOMEM;
> +
> +	mutex_init(&imr->mutex);
> +	spin_lock_init(&imr->lock);
> +	imr->dev = &pdev->dev;
> +
> +	/* memory-mapped registers */
> +	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> +	imr->mmio = devm_ioremap_resource(&pdev->dev, res);
> +	if (IS_ERR(imr->mmio))
> +		return PTR_ERR(imr->mmio);
> +
> +	/* interrupt service routine registration */
> +	imr->irq = ret = platform_get_irq(pdev, 0);
> +	if (ret < 0) {
> +		dev_err(&pdev->dev, "cannot find IRQ\n");
> +		return ret;
> +	}
> +
> +	ret = devm_request_irq(&pdev->dev, imr->irq, imr_irq_handler, 0,
> +			       dev_name(&pdev->dev), imr);
> +	if (ret) {
> +		dev_err(&pdev->dev, "cannot claim IRQ %d\n", imr->irq);
> +		return ret;
> +	}
> +
> +	imr->clock = devm_clk_get(&pdev->dev, NULL);
> +	if (IS_ERR(imr->clock)) {
> +		dev_err(&pdev->dev, "cannot get clock\n");
> +		return PTR_ERR(imr->clock);
> +	}
> +
> +	/* create v4l2 device */
> +	ret = v4l2_device_register(&pdev->dev, &imr->v4l2_dev);
> +	if (ret) {
> +		dev_err(&pdev->dev, "Failed to register v4l2 device\n");
> +		return ret;
> +	}
> +
> +	/* create mem2mem device handle */
> +	imr->m2m_dev = v4l2_m2m_init(&imr_m2m_ops);
> +	if (IS_ERR(imr->m2m_dev)) {
> +		v4l2_err(&imr->v4l2_dev, "Failed to init mem2mem device\n");
> +		ret = PTR_ERR(imr->m2m_dev);
> +		goto device_register_rollback;
> +	}
> +
> +	strlcpy(imr->video_dev.name, dev_name(&pdev->dev),
> +		sizeof(imr->video_dev.name));
> +	imr->video_dev.fops	    = &imr_fops;
> +	imr->video_dev.device_caps  = V4L2_CAP_VIDEO_CAPTURE |
> +				      V4L2_CAP_VIDEO_OUTPUT |
> +				      V4L2_CAP_VIDEO_M2M | V4L2_CAP_STREAMING;

Only specify V4L2_CAP_VIDEO_M2M | V4L2_CAP_STREAMING.
M2M cannot be combined with CAPTURE and OUTPUT.

> +	imr->video_dev.ioctl_ops    = &imr_ioctl_ops;
> +	imr->video_dev.minor	    = -1;
> +	imr->video_dev.release	    = video_device_release_empty;
> +	imr->video_dev.lock	    = &imr->mutex;
> +	imr->video_dev.v4l2_dev	    = &imr->v4l2_dev;
> +	imr->video_dev.vfl_dir	    = VFL_DIR_M2M;
> +
> +	ret = video_register_device(&imr->video_dev, VFL_TYPE_GRABBER, -1);
> +	if (ret) {
> +		v4l2_err(&imr->v4l2_dev, "Failed to register video device\n");
> +		goto m2m_init_rollback;
> +	}
> +
> +	video_set_drvdata(&imr->video_dev, imr);
> +	platform_set_drvdata(pdev, imr);
> +
> +	v4l2_info(&imr->v4l2_dev,
> +		  "IMR device (pdev: %d) registered as /dev/video%d\n",
> +		  pdev->id, imr->video_dev.num);
> +
> +	return 0;
> +
> +m2m_init_rollback:
> +	v4l2_m2m_release(imr->m2m_dev);
> +
> +device_register_rollback:
> +	v4l2_device_unregister(&imr->v4l2_dev);
> +
> +	return ret;
> +}
> +
> +static int imr_remove(struct platform_device *pdev)
> +{
> +	struct imr_device *imr = platform_get_drvdata(pdev);
> +
> +	video_unregister_device(&imr->video_dev);
> +	v4l2_m2m_release(imr->m2m_dev);
> +	v4l2_device_unregister(&imr->v4l2_dev);
> +
> +	return 0;
> +}
> +
> +/*******************************************************************************
> + * Power management
> + ******************************************************************************/
> +
> +#ifdef CONFIG_PM_SLEEP
> +
> +/* device suspend hook; clock control only - TBD */
> +static int imr_pm_suspend(struct device *dev)
> +{
> +	struct imr_device *imr = dev_get_drvdata(dev);
> +
> +	WARN_ON(mutex_is_locked(&imr->mutex));
> +
> +	if (imr->refcount == 0)
> +		return 0;
> +
> +	clk_disable_unprepare(imr->clock);
> +
> +	return 0;
> +}
> +
> +/* device resume hook; clock control only */
> +static int imr_pm_resume(struct device *dev)
> +{
> +	struct imr_device *imr = dev_get_drvdata(dev);
> +
> +	WARN_ON(mutex_is_locked(&imr->mutex));
> +
> +	if (imr->refcount == 0)
> +		return 0;
> +
> +	clk_prepare_enable(imr->clock);
> +
> +	return 0;
> +}
> +
> +#endif  /* CONFIG_PM_SLEEP */
> +
> +/* power management callbacks */
> +static const struct dev_pm_ops imr_pm_ops = {
> +	SET_SYSTEM_SLEEP_PM_OPS(imr_pm_suspend, imr_pm_resume)
> +};
> +
> +/* device table */
> +static const struct of_device_id imr_of_match[] = {
> +	{ .compatible = "renesas,imr-lx4" },
> +	{ },
> +};
> +
> +/* platform driver interface */
> +static struct platform_driver imr_platform_driver = {
> +	.probe		= imr_probe,
> +	.remove		= imr_remove,
> +	.driver		= {
> +		.owner		= THIS_MODULE,
> +		.name		= "imr",
> +		.pm		= &imr_pm_ops,
> +		.of_match_table = imr_of_match,
> +	},
> +};
> +
> +module_platform_driver(imr_platform_driver);
> +
> +MODULE_ALIAS("imr");
> +MODULE_AUTHOR("Cogent Embedded Inc. <sources@cogentembedded.com>");
> +MODULE_DESCRIPTION("Renesas IMR-LX4 Driver");
> +MODULE_LICENSE("GPL");
> Index: media_tree/include/uapi/linux/rcar_imr.h
> ===================================================================
> --- /dev/null
> +++ media_tree/include/uapi/linux/rcar_imr.h
> @@ -0,0 +1,94 @@
> +/*
> + * rcar_imr.h -- R-Car IMR-LX4 Driver UAPI
> + *
> + * Copyright (C) 2016-2017 Cogent Embedded, Inc. <source@cogentembedded.com>
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License as published by
> + * the Free Software Foundation; either version 2 of the License, or
> + * (at your option) any later version.
> + */
> +
> +#ifndef __RCAR_IMR_H
> +#define __RCAR_IMR_H
> +
> +#include <linux/videodev2.h>
> +
> +/*******************************************************************************
> + * Mapping specification descriptor
> + ******************************************************************************/
> +
> +struct imr_map_desc {
> +	/* mapping types */
> +	__u32			type;
> +
> +	/* total size of the mesh structure */
> +	__u32			size;
> +
> +	/* map-specific user-pointer */
> +	__u64			data;
> +} __packed;
> +
> +/* regular mesh specification */
> +#define IMR_MAP_MESH		(1 << 0)
> +
> +/* auto-generated source coordinates */
> +#define IMR_MAP_AUTOSG		(1 << 1)
> +
> +/* auto-generated destination coordinates */
> +#define IMR_MAP_AUTODG		(1 << 2)
> +
> +/* luminance correction flag */
> +#define IMR_MAP_LUCE		(1 << 3)
> +
> +/* chromacity correction flag */

chromacity? You probably mean just plain 'chroma'. Ditto below.

> +#define IMR_MAP_CLCE		(1 << 4)
> +
> +/* vertex clockwise-mode order */
> +#define IMR_MAP_TCM		(1 << 5)
> +
> +/* source coordinate decimal point position */
> +#define __IMR_MAP_UVDPOR_SHIFT	8
> +#define __IMR_MAP_UVDPOR(v)	(((v) >> __IMR_MAP_UVDPOR_SHIFT) & 0x7)
> +#define IMR_MAP_UVDPOR(n)	(((n) & 0x7) << __IMR_MAP_UVDPOR_SHIFT)
> +
> +/* destination coordinate sub-pixel mode */
> +#define IMR_MAP_DDP		(1 << 11)
> +
> +/* luminance correction offset decimal point position */
> +#define __IMR_MAP_YLDPO_SHIFT	12
> +#define __IMR_MAP_YLDPO(v)	(((v) >> __IMR_MAP_YLDPO_SHIFT) & 0x7)
> +#define IMR_MAP_YLDPO(n)	(((n) & 0x7) << __IMR_MAP_YLDPO_SHIFT)
> +
> +/* chromacity (U) correction offset decimal point position */
> +#define __IMR_MAP_UBDPO_SHIFT	15
> +#define __IMR_MAP_UBDPO(v)	(((v) >> __IMR_MAP_UBDPO_SHIFT) & 0x7)
> +#define IMR_MAP_UBDPO(n)	(((n) & 0x7) << __IMR_MAP_UBDPO_SHIFT)
> +
> +/* chromacity (V) correction offset decimal point position */
> +#define __IMR_MAP_VRDPO_SHIFT	18
> +#define __IMR_MAP_VRDPO(v)	(((v) >> __IMR_MAP_VRDPO_SHIFT) & 0x7)
> +#define IMR_MAP_VRDPO(n)	(((n) & 0x7) << __IMR_MAP_VRDPO_SHIFT)
> +
> +/* regular mesh specification */
> +struct imr_mesh {
> +	/* rectangular mesh size */
> +	__u16			rows, columns;
> +
> +	/* mesh parameters */
> +	__u16			x0, y0, dx, dy;
> +} __packed;
> +
> +/* vertex-buffer-object (VBO) descriptor */
> +struct imr_vbo {
> +	/* number of triangles */
> +	__u16			num;
> +} __packed;
> +
> +/*******************************************************************************
> + * Private IOCTL codes
> + ******************************************************************************/
> +
> +#define VIDIOC_IMR_MESH _IOW('V', BASE_VIDIOC_PRIVATE + 0, struct imr_map_desc)
> +
> +#endif /* __RCAR_IMR_H */
> 

I'll post a review of the uapi mesh documentation separately.

Regards,

	Hans
Hans Verkuil July 3, 2017, 12:43 p.m. UTC | #5
On 06/23/2017 10:34 PM, Sergei Shtylyov wrote:
> Index: media_tree/Documentation/media/v4l-drivers/rcar_imr.rst
> ===================================================================
> --- /dev/null
> +++ media_tree/Documentation/media/v4l-drivers/rcar_imr.rst
> @@ -0,0 +1,86 @@
> +Renesas R-Car Image Rendeder (IMR) Driver

Rendeder -> Renderer

> +=========================================
> +
> +This file documents some driver-specific aspects of the IMR driver, such as
> +driver-specific ioctls.
> +
> +The ioctl reference
> +~~~~~~~~~~~~~~~~~~~
> +
> +VIDIOC_IMR_MESH - Set mapping data
> +^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
> +
> +Argument: struct imr_map_desc
> +
> +**Description**:
> +
> +	This ioctl sets up the mesh using which the input frames will be

s/using/through/

> +	transformed into the output frames. The mesh can be strictly rectangular
> +	(when IMR_MAP_MESH bit is set in imr_map_desc::type) or arbitrary (when
> +	that bit is not set).
> +
> +	A rectangular mesh consists of the imr_mesh structure followed by M*N
> +	vertex objects (where M is imr_mesh::rows and N is imr_mesh::columns).
> +	In case either IMR_MAP_AUTOSG or IMR_MAP_AUTODG bits were set in
> +	imr_map_desc::type, imr_mesh::{x|y}0 specify the coordinates of the top
> +	left corner of the auto-generated mesh and imr_mesh::d{x|y} specify the
> +	mesh's X/Y steps.

What if any of the other types are used like IMR_MAP_LUCE?

Is this documented in a Renesas datasheet? If so, add a reference to that in this
documentation.

> +
> +	An arbitrary mesh consists of the imr_vbo structure followed by N
> +	triangle objects (where N is imr_vbo::num), consisting of 3 vertex
> +	objects each.
> +
> +	A vertex object has a complex structure:
> +
> +.. code-block:: none
> +
> +	__u16	v		vertical   \ source coordinates (only present
> +	__u16	u		horizontal / if IMR_MAP_AUTOSG isn't set)
> +	__u16	Y		vertical   \ destination coordinates (only here
> +	__u16	X		horizontal / if IMR_MAP_AUTODG isn't set)
> +	__s8	lofst		offset \  luminance correction parameters
> +	__u8	lscal		scale   > (only present if IMR_MAP_LUCE
> +	__u16	reserved	       /  is set)
> +	__s8	vrofs		V value offset \  hue correction parameters
> +	__u8	vrscl		V value scale   \ (only present if IMR_MAP_CLCE
> +	__s8	ubofs		U value offset  / is set)
> +	__u8	ubscl		U value scale  /

Is this the internal structure? Or something that userspace has to fill in?
It's not clear at all.

I recommend giving a few code examples of how this should be used.

> +
> +**Return value**:
> +
> +	On success 0 is returned. On error -1 is returned and errno is set
> +	appropriately.
> +
> +**Data types**:
> +
> +.. code-block:: none
> +
> +	* struct imr_map_desc
> +
> +	__u32	type		mapping types

This is a bitmask? If so, what combination of bits are allowed?

> +	__u32	size		total size of the mesh structure
> +	__u64	data		map-specific user-pointer
> +
> +	IMR_MAP_MESH		regular mesh specification
> +	IMR_MAP_AUTOSG		auto-generated source coordinates
> +	IMR_MAP_AUTODG		auto-generated destination coordinates
> +	IMR_MAP_LUCE		luminance correction flag
> +	IMR_MAP_CLCE		chromacity correction flag

You probably mean 'chroma'. 'chromacity' isn't a word.

> +	IMR_MAP_TCM		vertex clockwise-mode order
> +	IMR_MAP_UVDPOR(n)	source coordinate decimal point position
> +	IMR_MAP_DDP		destination coordinate sub-pixel mode
> +	IMR_MAP_YLDPO(n)	luminance correction offset decimal point
> +				position
> +	IMR_MAP_UBDPO(n)	chromacity (U) correction offset decimal point
> +				position
> +	IMR_MAP_VRDPO(n)	chromacity (V) correction offset decimal point
> +				position

There is no documentation what how these types relate to IMR_MAP_MESH and
IMR_MAP_AUTOS/DG.

> +
> +	* struct imr_mesh	regular mesh specification
> +
> +	__u16	rows, columns	rectangular mesh sizes
> +	__u16	x0, y0, dx, dy	auto-generated mesh parameters
> +
> +	* struct imr_vbo	vertex-buffer-object (VBO) descriptor
> +
> +	__u16	num		number of triangles

Sorry, this needs more work.

Regards,

	Hans
Sergei Shtylyov July 5, 2017, 9:01 p.m. UTC | #6
Hello!

On 07/03/2017 03:25 PM, Hans Verkuil wrote:

>> From: Konstantin Kozhevnikov <Konstantin.Kozhevnikov@cogentembedded.com>
>>
>> The image renderer, or the distortion correction engine, is a drawing
>> processor with a simple instruction system capable of referencing video
>> capture data or data in an external memory as the 2D texture data and
>> performing texture mapping and drawing with respect to any shape that is
>> split into triangular objects.
>>
>> This V4L2 memory-to-memory device driver only supports image renderer light
>> extended 4 (IMR-LX4) found in the R-Car gen3 SoCs; the R-Car gen2 support
>> can be added later...
>>
>> [Sergei: merged 2 original patches, added  the patch description, removed
>> unrelated parts,  added the binding document and the UAPI documentation,
>> ported the driver to the modern kernel, renamed the UAPI header file and
>> the guard macros to match the driver name, extended the copyrights, fixed
>> up Kconfig prompt/depends/help, made use of the BIT/GENMASK() macros,
>> sorted  #include's, replaced 'imr_ctx::crop' array with the 'imr_ctx::rect'
>> structure, replaced imr_{g|s}_crop() with imr_{g|s}_selection(), completely
>> rewrote imr_queue_setup(), removed 'imr_format_info::name', moved the
>> applicable code from imr_buf_queue() to imr_buf_prepare() and moved the
>> rest of imr_buf_queue() after imr_buf_finish(), assigned 'src_vq->dev' and
>> 'dst_vq->dev' in imr_queue_init(), removed imr_start_streaming(), assigned
>> 'src_vq->dev' and 'dst_vq->dev' in imr_queue_init(), clarified the math in
>> imt_tri_type_{a|b|c}_length(), clarified the pointer math and avoided casts
>> to 'void *' in imr_tri_set_type_{a|b|c}(), replaced imr_{reqbufs|querybuf|
>> dqbuf|expbuf|streamon|streamoff}() with the generic helpers, implemented
>> vidioc_{create_bufs|prepare_buf}() methods, used ALIGN() macro and merged
>> the matrix size checks and replaced kmalloc()/copy_from_user() calls with
>> memdup_user() call in imr_ioctl_map(), moved setting device capabilities
>> from imr_querycap() to imr_probe(), set the valid default queue format in
>> imr_probe(), removed leading dots and fixed grammar in the comments, fixed
>> up  the indentation  to use  tabs where possible, renamed DLSR, CMRCR.
>> DY1{0|2}, and ICR bits to match the manual, changed the prefixes of the
>> CMRCR[2]/TRI{M|C}R bits/fields to match the manual, removed non-existent
>> TRIMR.D{Y|U}D{X|V}M bits, added/used the IMR/{UV|CP}DPOR/SUSR bits/fields/
>> shifts, separated the register offset/bit #define's, sorted instruction
>> macros by opcode, removed unsupported LINE instruction, masked the register
>> address in WTL[2]/WTS instruction macros, moved the display list #define's
>> after the register #define's, removing the redundant comment, avoided
>> setting reserved bits when writing CMRCCR[2]/TRIMCR, used the SR bits
>> instead of a bare number, removed *inline* from .c file, fixed lines over
>> 80 columns, removed useless spaces, comments, parens, operators, casts,
>> braces, variables, #include's, statements, and even 1 function, added
>> useful local variable, uppercased and spelled out the abbreviations,
>> made comment wording more consistent/correct, fixed the comment typos,
>> reformatted some multiline comments, inserted empty line after declaration,
>> removed extra empty lines,  reordered some local variable desclarations,
>> removed calls to 4l2_err() on kmalloc() failure, replaced '*' with 'x'
>> in some format strings for v4l2_dbg(), fixed the error returned by
>> imr_default(), avoided code duplication in the IRQ handler, used '__packed'
>> for the UAPI structures, declared 'imr_map_desc::data' as '__u64' instead
>> of 'void *', switched to '__u{16|32}' in the UAPI header, enclosed the
>> macro parameters in parens, exchanged the values of IMR_MAP_AUTO{S|D}G
>> macros.]
>
> As Geert suggested, just replace this with a 'Based-on' line.

    OK, the list grew too long indeed. :-)

> <snip>
>
>> Index: media_tree/drivers/media/platform/rcar_imr.c
>> ===================================================================
>> --- /dev/null
>> +++ media_tree/drivers/media/platform/rcar_imr.c
>> @@ -0,0 +1,1877 @@
>
> <snip>
>
>> +/* add reference to the current configuration */
>> +static struct imr_cfg *imr_cfg_ref(struct imr_ctx *ctx)
>
> imr_cfg_ref -> imr_cfg_ref_get

    OK, but imr_cfg_get() seems a better name.

>> +{
>> +    struct imr_cfg *cfg = ctx->cfg;
>> +
>> +    BUG_ON(!cfg);
>
> Perhaps this can be replaced by:
>
>     if (WARN_ON(!cfg))
>         return NULL;

    I'm afraid imr_device_run() will cause oops in this case...

>> +    cfg->refcount++;
>> +    return cfg;
>> +}
>> +
>> +/* mesh configuration destructor */
>> +static void imr_cfg_unref(struct imr_ctx *ctx, struct imr_cfg *cfg)
>
> imr_cfg_unref -> imr_cfg_ref_put

   OK, but I'll call it imr_cfg_put().

> That follows the standard naming conventions for refcounting.
>
>> +{
>> +    struct imr_device *imr = ctx->imr;
>> +
>> +    /* no atomicity is required as operation is locked with device mutex */
>> +    if (!cfg || --cfg->refcount)
>> +        return;
>> +
>> +    /* release memory allocated for a display list */
>> +    if (cfg->dl_vaddr)
>> +        dma_free_writecombine(imr->dev, cfg->dl_size, cfg->dl_vaddr,
>> +                      cfg->dl_dma_addr);
>> +
>> +    /* destroy the configuration structure */
>> +    kfree(cfg);
>
> Add:
>     ctx->cfg = NULL;

   Thanks, makes sense indeed.

[...]
>> +static int imr_qbuf(struct file *file, void *priv, struct v4l2_buffer *buf)
>> +{
>> +    struct imr_ctx *ctx = fh_to_ctx(priv);
>> +
>> +    /* operation is protected with a queue lock */
>> +    WARN_ON(!mutex_is_locked(&ctx->imr->mutex));
>
> It's guaranteed by the V4L2 core, so this can be dropped safely.
>
>> +
>> +    /* verify the configuration is complete */
>> +    if (!ctx->cfg) {
>> +        v4l2_err(&ctx->imr->v4l2_dev,
>> +             "stream configuration is not complete\n");
>> +        return -EINVAL;
>> +    }
>
> Shouldn't this test be done in the buf_prepare callback above? It's
> what buf_prepare is for.
>
> Then you can drop this function and use the helper function instead.

    OK, will look into this...

>> +
>> +    return v4l2_m2m_qbuf(file, ctx->m2m_ctx, buf);
>> +}
[...]
>> +static unsigned int imr_poll(struct file *file, struct poll_table_struct
>> *wait)
>> +{
>> +    struct imr_ctx        *ctx = fh_to_ctx(file->private_data);
>> +    struct imr_device    *imr = video_drvdata(file);
>> +    unsigned int        res;
>> +
>> +    if (mutex_lock_interruptible(&imr->mutex))
>> +        return -ERESTARTSYS;
>> +
>> +    res = v4l2_m2m_poll(file, ctx->m2m_ctx, wait);
>> +    mutex_unlock(&imr->mutex);
>> +
>> +    return res;
>> +}
>
> Set the struct v4l2_m2m_ctx q_lock field to imr->mutex.
>
> Then you can use v4l2_m2m_fop_poll instead.

    Will look into this.

>> +
>> +static int imr_mmap(struct file *file, struct vm_area_struct *vma)
>> +{
>> +    struct imr_device    *imr = video_drvdata(file);
>> +    struct imr_ctx        *ctx = fh_to_ctx(file->private_data);
>> +    int            ret;
>> +
>> +    /* should we protect all M2M operations with mutex? - TBD */
>> +    if (mutex_lock_interruptible(&imr->mutex))
>> +        return -ERESTARTSYS;
>> +
>> +    ret = v4l2_m2m_mmap(file, ctx->m2m_ctx, vma);
>> +
>> +    mutex_unlock(&imr->mutex);
>> +
>> +    return ret;
>> +}
>
> Use v4l2_m2m_fop_mmap. And this is one file operation where you shouldn't lock.
> The vb2 core has a special mutex to handle this.

    OK, will see.

[...]
>> +/*******************************************************************************
>>
>> + * Device probing/removal interface
>> +
>> ******************************************************************************/
>> +
>> +static int imr_probe(struct platform_device *pdev)
>> +{
>> +    struct imr_device    *imr;
>> +    struct resource        *res;
>> +    int            ret;
>> +
>> +    imr = devm_kzalloc(&pdev->dev, sizeof(*imr), GFP_KERNEL);
>> +    if (!imr)
>> +        return -ENOMEM;
>> +
>> +    mutex_init(&imr->mutex);
>> +    spin_lock_init(&imr->lock);
>> +    imr->dev = &pdev->dev;
>> +
>> +    /* memory-mapped registers */
>> +    res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
>> +    imr->mmio = devm_ioremap_resource(&pdev->dev, res);
>> +    if (IS_ERR(imr->mmio))
>> +        return PTR_ERR(imr->mmio);
>> +
>> +    /* interrupt service routine registration */
>> +    imr->irq = ret = platform_get_irq(pdev, 0);
>> +    if (ret < 0) {
>> +        dev_err(&pdev->dev, "cannot find IRQ\n");
>> +        return ret;
>> +    }
>> +
>> +    ret = devm_request_irq(&pdev->dev, imr->irq, imr_irq_handler, 0,
>> +                   dev_name(&pdev->dev), imr);
>> +    if (ret) {
>> +        dev_err(&pdev->dev, "cannot claim IRQ %d\n", imr->irq);
>> +        return ret;
>> +    }
>> +
>> +    imr->clock = devm_clk_get(&pdev->dev, NULL);
>> +    if (IS_ERR(imr->clock)) {
>> +        dev_err(&pdev->dev, "cannot get clock\n");
>> +        return PTR_ERR(imr->clock);
>> +    }
>> +
>> +    /* create v4l2 device */
>> +    ret = v4l2_device_register(&pdev->dev, &imr->v4l2_dev);
>> +    if (ret) {
>> +        dev_err(&pdev->dev, "Failed to register v4l2 device\n");
>> +        return ret;
>> +    }
>> +
>> +    /* create mem2mem device handle */
>> +    imr->m2m_dev = v4l2_m2m_init(&imr_m2m_ops);
>> +    if (IS_ERR(imr->m2m_dev)) {
>> +        v4l2_err(&imr->v4l2_dev, "Failed to init mem2mem device\n");
>> +        ret = PTR_ERR(imr->m2m_dev);
>> +        goto device_register_rollback;
>> +    }
>> +
>> +    strlcpy(imr->video_dev.name, dev_name(&pdev->dev),
>> +        sizeof(imr->video_dev.name));
>> +    imr->video_dev.fops        = &imr_fops;
>> +    imr->video_dev.device_caps  = V4L2_CAP_VIDEO_CAPTURE |
>> +                      V4L2_CAP_VIDEO_OUTPUT |
>> +                      V4L2_CAP_VIDEO_M2M | V4L2_CAP_STREAMING;
>
> Only specify V4L2_CAP_VIDEO_M2M | V4L2_CAP_STREAMING.
> M2M cannot be combined with CAPTURE and OUTPUT.

    OK, sorry about that...

[...]
>> Index: media_tree/include/uapi/linux/rcar_imr.h
>> ===================================================================
>> --- /dev/null
>> +++ media_tree/include/uapi/linux/rcar_imr.h
>> @@ -0,0 +1,94 @@
>> +/*
>> + * rcar_imr.h -- R-Car IMR-LX4 Driver UAPI
>> + *
>> + * Copyright (C) 2016-2017 Cogent Embedded, Inc. <source@cogentembedded.com>
>> + *
>> + * This program is free software; you can redistribute it and/or modify
>> + * it under the terms of the GNU General Public License as published by
>> + * the Free Software Foundation; either version 2 of the License, or
>> + * (at your option) any later version.
>> + */
>> +
>> +#ifndef __RCAR_IMR_H
>> +#define __RCAR_IMR_H
>> +
>> +#include <linux/videodev2.h>
>> +
>> +/*******************************************************************************
>>
>> + * Mapping specification descriptor
>> +
>> ******************************************************************************/
>> +
>> +struct imr_map_desc {
>> +    /* mapping types */
>> +    __u32            type;
>> +
>> +    /* total size of the mesh structure */
>> +    __u32            size;
>> +
>> +    /* map-specific user-pointer */
>> +    __u64            data;
>> +} __packed;
>> +
>> +/* regular mesh specification */
>> +#define IMR_MAP_MESH        (1 << 0)
>> +
>> +/* auto-generated source coordinates */
>> +#define IMR_MAP_AUTOSG        (1 << 1)
>> +
>> +/* auto-generated destination coordinates */
>> +#define IMR_MAP_AUTODG        (1 << 2)
>> +
>> +/* luminance correction flag */
>> +#define IMR_MAP_LUCE        (1 << 3)
>> +
>> +/* chromacity correction flag */
>
> chromacity? You probably mean just plain 'chroma'. Ditto below.

    Hm, www.translate.ru knows this word. :-)

[...]

>
> Regards,
>
>     Hans

MBR, Sergei
Sergei Shtylyov July 6, 2017, 6:16 p.m. UTC | #7
Hello!

On 07/03/2017 03:43 PM, Hans Verkuil wrote:

>> Index: media_tree/Documentation/media/v4l-drivers/rcar_imr.rst
>> ===================================================================
>> --- /dev/null
>> +++ media_tree/Documentation/media/v4l-drivers/rcar_imr.rst
>> @@ -0,0 +1,86 @@
>> +Renesas R-Car Image Rendeder (IMR) Driver
>
> Rendeder -> Renderer

    Oops, sorry. :-)

>> +=========================================
>> +
>> +This file documents some driver-specific aspects of the IMR driver, such as
>> +driver-specific ioctls.
>> +
>> +The ioctl reference
>> +~~~~~~~~~~~~~~~~~~~
>> +
>> +VIDIOC_IMR_MESH - Set mapping data
>> +^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
>> +
>> +Argument: struct imr_map_desc
>> +
>> +**Description**:
>> +
>> +    This ioctl sets up the mesh using which the input frames will be
>
> s/using/through/
>
>> +    transformed into the output frames. The mesh can be strictly rectangular
>> +    (when IMR_MAP_MESH bit is set in imr_map_desc::type) or arbitrary (when
>> +    that bit is not set).
>> +
>> +    A rectangular mesh consists of the imr_mesh structure followed by M*N
>> +    vertex objects (where M is imr_mesh::rows and N is imr_mesh::columns).
>> +    In case either IMR_MAP_AUTOSG or IMR_MAP_AUTODG bits were set in
>> +    imr_map_desc::type, imr_mesh::{x|y}0 specify the coordinates of the top
>> +    left corner of the auto-generated mesh and imr_mesh::d{x|y} specify the
>> +    mesh's X/Y steps.
>
> What if any of the other types are used like IMR_MAP_LUCE?

    IMR_MAP_LUCE only affects the vertex object.

> Is this documented in a Renesas datasheet?

    Yes.

> If so, add a reference to that in this
> documentation.

    Unfortunately it's not publicly available.

>> +
>> +    An arbitrary mesh consists of the imr_vbo structure followed by N
>> +    triangle objects (where N is imr_vbo::num), consisting of 3 vertex
>> +    objects each.
>> +
>> +    A vertex object has a complex structure:
>> +
>> +.. code-block:: none
>> +
>> +    __u16    v        vertical   \ source coordinates (only present
>> +    __u16    u        horizontal / if IMR_MAP_AUTOSG isn't set)
>> +    __u16    Y        vertical   \ destination coordinates (only here
>> +    __u16    X        horizontal / if IMR_MAP_AUTODG isn't set)
>> +    __s8    lofst        offset \  luminance correction parameters
>> +    __u8    lscal        scale   > (only present if IMR_MAP_LUCE
>> +    __u16    reserved           /  is set)
>> +    __s8    vrofs        V value offset \  hue correction parameters
>> +    __u8    vrscl        V value scale   \ (only present if IMR_MAP_CLCE
>> +    __s8    ubofs        U value offset  / is set)
>> +    __u8    ubscl        U value scale  /
>
> Is this the internal structure? Or something that userspace has to fill in?

    Yes, the user space have to pass that to the driver which constructs the 
display lists using these data.

> It's not clear at all.
>
> I recommend giving a few code examples of how this should be used.

    Konstantin, can we give some examples?

>> +
>> +**Return value**:
>> +
>> +    On success 0 is returned. On error -1 is returned and errno is set
>> +    appropriately.
>> +
>> +**Data types**:
>> +
>> +.. code-block:: none
>> +
>> +    * struct imr_map_desc
>> +
>> +    __u32    type        mapping types
>
> This is a bitmask? If so, what combination of bits are allowed?

    Yes, bitmask.

>> +    __u32    size        total size of the mesh structure
>> +    __u64    data        map-specific user-pointer
>> +
>> +    IMR_MAP_MESH        regular mesh specification
>> +    IMR_MAP_AUTOSG        auto-generated source coordinates
>> +    IMR_MAP_AUTODG        auto-generated destination coordinates
>> +    IMR_MAP_LUCE        luminance correction flag
>> +    IMR_MAP_CLCE        chromacity correction flag
>
> You probably mean 'chroma'. 'chromacity' isn't a word.

    But it's recognized by all online translators I've tried. :-)

>> +    IMR_MAP_TCM        vertex clockwise-mode order
>> +    IMR_MAP_UVDPOR(n)    source coordinate decimal point position
>> +    IMR_MAP_DDP        destination coordinate sub-pixel mode
>> +    IMR_MAP_YLDPO(n)    luminance correction offset decimal point
>> +                position
>> +    IMR_MAP_UBDPO(n)    chromacity (U) correction offset decimal point
>> +                position
>> +    IMR_MAP_VRDPO(n)    chromacity (V) correction offset decimal point
>> +                position
>
> There is no documentation what how these types relate to IMR_MAP_MESH and
> IMR_MAP_AUTOS/DG.

    They are basically orthogonal, IIRC.

>> +
>> +    * struct imr_mesh    regular mesh specification
>> +
>> +    __u16    rows, columns    rectangular mesh sizes
>> +    __u16    x0, y0, dx, dy    auto-generated mesh parameters
>> +
>> +    * struct imr_vbo    vertex-buffer-object (VBO) descriptor
>> +
>> +    __u16    num        number of triangles
>
> Sorry, this needs more work.

    Sigh, everybody hates writing docs, I guess... :-)

> Regards,
>
>     Hans

MBR, Sergei
Konstantin Kozhevnikov July 8, 2017, 1:31 p.m. UTC | #8
Hello all,

the sample is made publicly available, and can be taken from 
https://github.com/CogentEmbedded/imr-sv-utest/blob/master/utest/utest-imr.c.

It doesn't show how luminance/chrominance correction actually works, 
however. That feature has been tested once a while ago, and probably we 
are going to release that soon.

Regarding usage of "chromacity" word in the comments, I actually meant 
"chrominance" or "chroma". The difference for non-native speaker is 
probably a bit vague, just like one between "luminance" and 
"luminosity". In the R-Car manual it is referred to as "hue", but what 
is meant is the "luma" and "chroma". These short forms seem a bit weird 
to me, hence I was using the words "luminance" and "chromacity". If 
that's confusing, I don't mind them be replaced with just "luma"/"chroma".

For documentation part, I am not 100% sure Renesas is okay with 
disclosing each and every detail, it might be the case we should obtain 
a permit from their legals. Still, I believe the person who is about to 
use the driver is having an access to at least Technical Reference 
Manual of R-Car Gen2/3, so adding a reference to a chapter in TRM will 
most likely be sufficient.

The question about usage of "user-pointer" buffers (V4L2_MEMORY_USERPTR) 
is a bit confusing. Indeed, right now we are using that scheme, though I 
wouldn't say we are absolutely required to do that. Specifically, we are 
allocating the contiguous buffers using Renesas' proprietary "mmngr" 
driver (it's not a rocket science thing, but it's made proprietary for 
some reason). Then we are using the buffers for various persons, both in 
EGL and in IMR. I guess we are okay with moving completely to DMA-fd 
(given the fact we have an accompanying driver "mmngrbuf" which serves 
for translation of memory pointers to DMA-fds for further cross-process 
sharing and stuff). I mean, if USERPTR is tagged as an obsolete / 
deprecated function, we are fine with dropping it. However, there is one 
thing I'd like to understand from V4L2 experts. I do see sometimes 
(during application closing or shortly after it) the bunches of warnings 
from kernel regarding "corrupted" MMU state (don't recall exactly, but 
it sounds like page which is supposed to be free gets somehow 
corrupted). Is that something that is related to (mis)use of USERPTR? I 
was trying to find out if there is any memory corruption caused by 
application logic, came to conclusion it's not. To me it looks like a 
race condition between unmapping of VMAs and V4L2 buffers deallocation 
which yields sometimes unpredictable results. Can you please provide 
some details about possible issues with usage of USERPTR with 
DMA-contiguous buffer driver, it would be good to find a match.

(Sorry, it got pretty long)

Sincerely,
Kostya

On 06/07/17 21:16, Sergei Shtylyov wrote:
> Hello!
>
> On 07/03/2017 03:43 PM, Hans Verkuil wrote:
>
>>> Index: media_tree/Documentation/media/v4l-drivers/rcar_imr.rst
>>> ===================================================================
>>> --- /dev/null
>>> +++ media_tree/Documentation/media/v4l-drivers/rcar_imr.rst
>>> @@ -0,0 +1,86 @@
>>> +Renesas R-Car Image Rendeder (IMR) Driver
>>
>> Rendeder -> Renderer
>
>    Oops, sorry. :-)
>
>>> +=========================================
>>> +
>>> +This file documents some driver-specific aspects of the IMR driver, 
>>> such as
>>> +driver-specific ioctls.
>>> +
>>> +The ioctl reference
>>> +~~~~~~~~~~~~~~~~~~~
>>> +
>>> +VIDIOC_IMR_MESH - Set mapping data
>>> +^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
>>> +
>>> +Argument: struct imr_map_desc
>>> +
>>> +**Description**:
>>> +
>>> +    This ioctl sets up the mesh using which the input frames will be
>>
>> s/using/through/
>>
>>> +    transformed into the output frames. The mesh can be strictly 
>>> rectangular
>>> +    (when IMR_MAP_MESH bit is set in imr_map_desc::type) or 
>>> arbitrary (when
>>> +    that bit is not set).
>>> +
>>> +    A rectangular mesh consists of the imr_mesh structure followed 
>>> by M*N
>>> +    vertex objects (where M is imr_mesh::rows and N is 
>>> imr_mesh::columns).
>>> +    In case either IMR_MAP_AUTOSG or IMR_MAP_AUTODG bits were set in
>>> +    imr_map_desc::type, imr_mesh::{x|y}0 specify the coordinates of 
>>> the top
>>> +    left corner of the auto-generated mesh and imr_mesh::d{x|y} 
>>> specify the
>>> +    mesh's X/Y steps.
>>
>> What if any of the other types are used like IMR_MAP_LUCE?
>
>    IMR_MAP_LUCE only affects the vertex object.
>
>> Is this documented in a Renesas datasheet?
>
>    Yes.
>
>> If so, add a reference to that in this
>> documentation.
>
>    Unfortunately it's not publicly available.
>
>>> +
>>> +    An arbitrary mesh consists of the imr_vbo structure followed by N
>>> +    triangle objects (where N is imr_vbo::num), consisting of 3 vertex
>>> +    objects each.
>>> +
>>> +    A vertex object has a complex structure:
>>> +
>>> +.. code-block:: none
>>> +
>>> +    __u16    v        vertical   \ source coordinates (only present
>>> +    __u16    u        horizontal / if IMR_MAP_AUTOSG isn't set)
>>> +    __u16    Y        vertical   \ destination coordinates (only here
>>> +    __u16    X        horizontal / if IMR_MAP_AUTODG isn't set)
>>> +    __s8    lofst        offset \  luminance correction parameters
>>> +    __u8    lscal        scale   > (only present if IMR_MAP_LUCE
>>> +    __u16    reserved           /  is set)
>>> +    __s8    vrofs        V value offset \  hue correction parameters
>>> +    __u8    vrscl        V value scale   \ (only present if 
>>> IMR_MAP_CLCE
>>> +    __s8    ubofs        U value offset  / is set)
>>> +    __u8    ubscl        U value scale  /
>>
>> Is this the internal structure? Or something that userspace has to 
>> fill in?
>
>    Yes, the user space have to pass that to the driver which 
> constructs the display lists using these data.
>
>> It's not clear at all.
>>
>> I recommend giving a few code examples of how this should be used.
>
>    Konstantin, can we give some examples?
>
>>> +
>>> +**Return value**:
>>> +
>>> +    On success 0 is returned. On error -1 is returned and errno is set
>>> +    appropriately.
>>> +
>>> +**Data types**:
>>> +
>>> +.. code-block:: none
>>> +
>>> +    * struct imr_map_desc
>>> +
>>> +    __u32    type        mapping types
>>
>> This is a bitmask? If so, what combination of bits are allowed?
>
>    Yes, bitmask.
>
>>> +    __u32    size        total size of the mesh structure
>>> +    __u64    data        map-specific user-pointer
>>> +
>>> +    IMR_MAP_MESH        regular mesh specification
>>> +    IMR_MAP_AUTOSG        auto-generated source coordinates
>>> +    IMR_MAP_AUTODG        auto-generated destination coordinates
>>> +    IMR_MAP_LUCE        luminance correction flag
>>> +    IMR_MAP_CLCE        chromacity correction flag
>>
>> You probably mean 'chroma'. 'chromacity' isn't a word.
>
>    But it's recognized by all online translators I've tried. :-)
>
>>> +    IMR_MAP_TCM        vertex clockwise-mode order
>>> +    IMR_MAP_UVDPOR(n)    source coordinate decimal point position
>>> +    IMR_MAP_DDP        destination coordinate sub-pixel mode
>>> +    IMR_MAP_YLDPO(n)    luminance correction offset decimal point
>>> +                position
>>> +    IMR_MAP_UBDPO(n)    chromacity (U) correction offset decimal point
>>> +                position
>>> +    IMR_MAP_VRDPO(n)    chromacity (V) correction offset decimal point
>>> +                position
>>
>> There is no documentation what how these types relate to IMR_MAP_MESH 
>> and
>> IMR_MAP_AUTOS/DG.
>
>    They are basically orthogonal, IIRC.
>
>>> +
>>> +    * struct imr_mesh    regular mesh specification
>>> +
>>> +    __u16    rows, columns    rectangular mesh sizes
>>> +    __u16    x0, y0, dx, dy    auto-generated mesh parameters
>>> +
>>> +    * struct imr_vbo    vertex-buffer-object (VBO) descriptor
>>> +
>>> +    __u16    num        number of triangles
>>
>> Sorry, this needs more work.
>
>    Sigh, everybody hates writing docs, I guess... :-)
>
>> Regards,
>>
>>     Hans
>
> MBR, Sergei
>
Sergei Shtylyov July 12, 2017, 8:26 p.m. UTC | #9
Hello!

On 07/06/2017 09:16 PM, Sergei Shtylyov wrote:

[...]
>>> +=========================================
>>> +
>>> +This file documents some driver-specific aspects of the IMR driver, such as
>>> +driver-specific ioctls.
>>> +
>>> +The ioctl reference
>>> +~~~~~~~~~~~~~~~~~~~
>>> +
>>> +VIDIOC_IMR_MESH - Set mapping data
>>> +^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
>>> +
>>> +Argument: struct imr_map_desc
>>> +
>>> +**Description**:
>>> +
>>> +    This ioctl sets up the mesh using which the input frames will be
>>
>> s/using/through/
>>
>>> +    transformed into the output frames. The mesh can be strictly rectangular
>>> +    (when IMR_MAP_MESH bit is set in imr_map_desc::type) or arbitrary (when
>>> +    that bit is not set).
>>> +
>>> +    A rectangular mesh consists of the imr_mesh structure followed by M*N
>>> +    vertex objects (where M is imr_mesh::rows and N is imr_mesh::columns).
>>> +    In case either IMR_MAP_AUTOSG or IMR_MAP_AUTODG bits were set in
>>> +    imr_map_desc::type, imr_mesh::{x|y}0 specify the coordinates of the top
>>> +    left corner of the auto-generated mesh and imr_mesh::d{x|y} specify the
>>> +    mesh's X/Y steps.
>>
>> What if any of the other types are used like IMR_MAP_LUCE?
>
>    IMR_MAP_LUCE only affects the vertex object.
>
>> Is this documented in a Renesas datasheet?
>
>    Yes.

    Well, not exactly. The different mesh types are a software concept, the 
hardware only understands series of triangles.

[...]

>> Regards,
>>
>>     Hans

MBR, Sergei
Hans Verkuil July 18, 2017, 11:49 a.m. UTC | #10
On 08/07/17 15:31, Konstantin Kozhevnikov wrote:
> Hello all,
> 
> the sample is made publicly available, and can be taken from https://github.com/CogentEmbedded/imr-sv-utest/blob/master/utest/utest-imr.c.
> 
> It doesn't show how luminance/chrominance correction actually works, however. That feature has been tested once a while ago, and probably we are going to release that soon.
> 
> Regarding usage of "chromacity" word in the comments, I actually meant "chrominance" or "chroma". The difference for non-native speaker is probably a bit vague, just like one between "luminance" and
> "luminosity". In the R-Car manual it is referred to as "hue", but what is meant is the "luma" and "chroma". These short forms seem a bit weird to me, hence I was using the words "luminance" and
> "chromacity". If that's confusing, I don't mind them be replaced with just "luma"/"chroma".

luma/chroma works well for me. 'chromacity' was confusing for me because it is close to
'chromaticity' which is a valid word but it has a different meaning.

> 
> For documentation part, I am not 100% sure Renesas is okay with disclosing each and every detail, it might be the case we should obtain a permit from their legals. Still, I believe the person who is
> about to use the driver is having an access to at least Technical Reference Manual of R-Car Gen2/3, so adding a reference to a chapter in TRM will most likely be sufficient.

A reference to the TRM is fine. I assume people who write code for this will have the TRM
available.

Regarding the code: having that example code is certainly useful, but what I am really looking
for is a code snippet that allocates and fills in the data to pass on with the ioctl.

Especially the handling of the 'type' field remains very fuzzy to me. Especially the fact
that it is a bitmask is strange. Usually a type is an enum that defines how to interpret
the struct (e.g. similar to type in struct v4l2_format). I get the feeling your mixing
type with flags. Perhaps if you split it up into a type and flags field things will make
more sense.

> 
> The question about usage of "user-pointer" buffers (V4L2_MEMORY_USERPTR) is a bit confusing. Indeed, right now we are using that scheme, though I wouldn't say we are absolutely required to do that.
> Specifically, we are allocating the contiguous buffers using Renesas' proprietary "mmngr" driver (it's not a rocket science thing, but it's made proprietary for some reason). Then we are using the
> buffers for various persons, both in EGL and in IMR. I guess we are okay with moving completely to DMA-fd (given the fact we have an accompanying driver "mmngrbuf" which serves for translation of
> memory pointers to DMA-fds for further cross-process sharing and stuff). I mean, if USERPTR is tagged as an obsolete / deprecated function, we are fine with dropping it. However, there is one thing
> I'd like to understand from V4L2 experts. I do see sometimes (during application closing or shortly after it) the bunches of warnings from kernel regarding "corrupted" MMU state (don't recall exactly,
> but it sounds like page which is supposed to be free gets somehow corrupted). Is that something that is related to (mis)use of USERPTR? I was trying to find out if there is any memory corruption
> caused by application logic, came to conclusion it's not. To me it looks like a race condition between unmapping of VMAs and V4L2 buffers deallocation which yields sometimes unpredictable results. Can
> you please provide some details about possible issues with usage of USERPTR with DMA-contiguous buffer driver, it would be good to find a match.

I am not aware of any warnings like you described.

Originally USERPTR was designed to be used with scatter-gather DMA engines. It requires
a really good DMA engine that is able to handle partial pages and address alignments
of 8 bytes or less. That way it allowed userspace to use malloc to allocate the buffers.

Later it was abused for embedded systems that used contiguous DMA but had special code
that carved out memory. Userspace would pass a pointer to the driver using the USERPTR
API and the driver would verify that it indeed pointed to physically contiguous memory.

When dmabuf came along (together with the CMA subsystem) the need for abusing USERPTR
in that way disappeared and our recommendation for new drivers is to always support
DMABUF and only use USERPTR if the hardware can *really* handle malloc()ed buffers.

I.e. without special alignment requirements such as the buffer must start at a page
boundary. Most hardware fails that test.

In practice we discourage the use of USERPTR for embedded systems.

Apologies for the delay in replying, I was on vacation last week.

Regards,

	Hans
diff mbox

Patch

Index: media_tree/Documentation/devicetree/bindings/media/rcar_imr.txt
===================================================================
--- /dev/null
+++ media_tree/Documentation/devicetree/bindings/media/rcar_imr.txt
@@ -0,0 +1,27 @@ 
+Renesas R-Car Image Renderer (Distortion Correction Engine)
+-----------------------------------------------------------
+
+The image renderer, or the distortion correction engine, is a drawing processor
+with a simple instruction system capable of referencing video capture data or
+data in an external memory as 2D texture data and performing texture mapping
+and drawing with respect to any shape that is split into triangular objects.
+
+Required properties:
+
+- compatible: "renesas,<soctype>-imr-lx4", "renesas,imr-lx4" as a fallback for
+  the image renderer light extended 4 (IMR-LX4) found in the R-Car gen3 SoCs,
+  where the examples with <soctype> are:
+  - "renesas,r8a7795-imr-lx4" for R-Car H3,
+  - "renesas,r8a7796-imr-lx4" for R-Car M3-W.
+- reg: offset and length of the register block;
+- interrupts: single interrupt specifier;
+- clocks: single clock phandle/specifier pair.
+
+Example:
+
+	imr-lx4@fe860000 {
+		compatible = "renesas,r8a7795-imr-lx4", "renesas,imr-lx4";
+		reg = <0 0xfe860000 0 0x2000>;
+		interrupts = <GIC_SPI 192 IRQ_TYPE_LEVEL_HIGH>;
+		clocks = <&cpg CPG_MOD 823>;
+	};
Index: media_tree/Documentation/media/v4l-drivers/index.rst
===================================================================
--- media_tree.orig/Documentation/media/v4l-drivers/index.rst
+++ media_tree/Documentation/media/v4l-drivers/index.rst
@@ -51,6 +51,7 @@  For more details see the file COPYING in
 	pxa_camera
 	radiotrack
 	rcar-fdp1
+	rcar_imr
 	saa7134
 	sh_mobile_ceu_camera
 	si470x
Index: media_tree/Documentation/media/v4l-drivers/rcar_imr.rst
===================================================================
--- /dev/null
+++ media_tree/Documentation/media/v4l-drivers/rcar_imr.rst
@@ -0,0 +1,86 @@ 
+Renesas R-Car Image Rendeder (IMR) Driver
+=========================================
+
+This file documents some driver-specific aspects of the IMR driver, such as
+driver-specific ioctls.
+
+The ioctl reference
+~~~~~~~~~~~~~~~~~~~
+
+VIDIOC_IMR_MESH - Set mapping data
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+Argument: struct imr_map_desc
+
+**Description**:
+
+	This ioctl sets up the mesh using which the input frames will be
+	transformed into the output frames. The mesh can be strictly rectangular
+	(when IMR_MAP_MESH bit is set in imr_map_desc::type) or arbitrary (when
+	that bit is not set).
+
+	A rectangular mesh consists of the imr_mesh structure followed by M*N
+	vertex objects (where M is imr_mesh::rows and N is imr_mesh::columns).
+	In case either IMR_MAP_AUTOSG or IMR_MAP_AUTODG bits were set in
+	imr_map_desc::type, imr_mesh::{x|y}0 specify the coordinates of the top
+	left corner of the auto-generated mesh and imr_mesh::d{x|y} specify the
+	mesh's X/Y steps.
+
+	An arbitrary mesh consists of the imr_vbo structure followed by N
+	triangle objects (where N is imr_vbo::num), consisting of 3 vertex
+	objects each.
+
+	A vertex object has a complex structure:
+
+.. code-block:: none
+
+	__u16	v		vertical   \ source coordinates (only present
+	__u16	u		horizontal / if IMR_MAP_AUTOSG isn't set)
+	__u16	Y		vertical   \ destination coordinates (only here
+	__u16	X		horizontal / if IMR_MAP_AUTODG isn't set)
+	__s8	lofst		offset \  luminance correction parameters
+	__u8	lscal		scale   > (only present if IMR_MAP_LUCE
+	__u16	reserved	       /  is set)
+	__s8	vrofs		V value offset \  hue correction parameters
+	__u8	vrscl		V value scale   \ (only present if IMR_MAP_CLCE
+	__s8	ubofs		U value offset  / is set)
+	__u8	ubscl		U value scale  /
+
+**Return value**:
+
+	On success 0 is returned. On error -1 is returned and errno is set
+	appropriately.
+
+**Data types**:
+
+.. code-block:: none
+
+	* struct imr_map_desc
+
+	__u32	type		mapping types
+	__u32	size		total size of the mesh structure
+	__u64	data		map-specific user-pointer
+
+	IMR_MAP_MESH		regular mesh specification
+	IMR_MAP_AUTOSG		auto-generated source coordinates
+	IMR_MAP_AUTODG		auto-generated destination coordinates
+	IMR_MAP_LUCE		luminance correction flag
+	IMR_MAP_CLCE		chromacity correction flag
+	IMR_MAP_TCM		vertex clockwise-mode order
+	IMR_MAP_UVDPOR(n)	source coordinate decimal point position
+	IMR_MAP_DDP		destination coordinate sub-pixel mode
+	IMR_MAP_YLDPO(n)	luminance correction offset decimal point
+				position
+	IMR_MAP_UBDPO(n)	chromacity (U) correction offset decimal point
+				position
+	IMR_MAP_VRDPO(n)	chromacity (V) correction offset decimal point
+				position
+
+	* struct imr_mesh	regular mesh specification
+
+	__u16	rows, columns	rectangular mesh sizes
+	__u16	x0, y0, dx, dy	auto-generated mesh parameters
+
+	* struct imr_vbo	vertex-buffer-object (VBO) descriptor
+
+	__u16	num		number of triangles
Index: media_tree/drivers/media/platform/Kconfig
===================================================================
--- media_tree.orig/drivers/media/platform/Kconfig
+++ media_tree/drivers/media/platform/Kconfig
@@ -437,6 +437,19 @@  config VIDEO_RENESAS_FCP
 	  To compile this driver as a module, choose M here: the module
 	  will be called rcar-fcp.
 
+config VIDEO_RENESAS_IMR
+	tristate "Renesas Image Renderer (Distortion Correction Engine)"
+	depends on VIDEO_DEV && VIDEO_V4L2
+	depends on ARCH_RENESAS || COMPILE_TEST
+	select VIDEOBUF2_DMA_CONTIG
+	select V4L2_MEM2MEM_DEV
+	---help---
+	  This is a V4L2 driver for the Renesas Image Renderer Light Extended 4
+	  (IMR-LX4).
+
+	  To compile this driver as a module, choose M here: the module
+	  will be called rcar_imr.
+
 config VIDEO_RENESAS_VSP1
 	tristate "Renesas VSP1 Video Processing Engine"
 	depends on VIDEO_V4L2 && VIDEO_V4L2_SUBDEV_API && HAS_DMA
Index: media_tree/drivers/media/platform/Makefile
===================================================================
--- media_tree.orig/drivers/media/platform/Makefile
+++ media_tree/drivers/media/platform/Makefile
@@ -60,6 +60,7 @@  obj-$(CONFIG_VIDEO_RCAR_DRIF)		+= rcar_d
 obj-$(CONFIG_VIDEO_RENESAS_FCP) 	+= rcar-fcp.o
 obj-$(CONFIG_VIDEO_RENESAS_FDP1)	+= rcar_fdp1.o
 obj-$(CONFIG_VIDEO_RENESAS_JPU) 	+= rcar_jpu.o
+obj-$(CONFIG_VIDEO_RENESAS_IMR) 	+= rcar_imr.o
 obj-$(CONFIG_VIDEO_RENESAS_VSP1)	+= vsp1/
 
 obj-y	+= omap/
Index: media_tree/drivers/media/platform/rcar_imr.c
===================================================================
--- /dev/null
+++ media_tree/drivers/media/platform/rcar_imr.c
@@ -0,0 +1,1877 @@ 
+/*
+ * rcar_imr.c -- R-Car IMR-LX4 Driver
+ *
+ * Copyright (C) 2015-2017 Cogent Embedded, Inc. <source@cogentembedded.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ */
+
+#include <linux/bitops.h>
+#include <linux/clk.h>
+#include <linux/interrupt.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/rcar_imr.h>
+#include <media/v4l2-ctrls.h>
+#include <media/v4l2-device.h>
+#include <media/v4l2-fh.h>
+#include <media/v4l2-ioctl.h>
+#include <media/v4l2-mem2mem.h>
+#include <media/v4l2-rect.h>
+#include <media/videobuf2-dma-contig.h>
+
+#define DRV_NAME		"rcar_imr"
+
+/*******************************************************************************
+ * Module parameters
+ ******************************************************************************/
+
+static int debug;
+module_param(debug, int, 0644);
+MODULE_PARM_DESC(debug, "Debug level (0-4)");
+
+/*******************************************************************************
+ * Local type definitions
+ ******************************************************************************/
+
+/* configuration data */
+struct imr_cfg {
+	/* display-list main program data */
+	void			*dl_vaddr;
+	dma_addr_t		dl_dma_addr;
+	u32			dl_size;
+	u32			dl_start_offset;
+
+	/* pointers to the source/destination planes */
+	u32			*src_pa_ptr[2];
+	u32			*dst_pa_ptr[2];
+
+	/* subpixel destination coordinates space */
+	int			dst_subpixel;
+
+	/* reference counter */
+	u32			refcount;
+
+	/* identifier (for debug output) */
+	u32			id;
+};
+
+struct imr_buffer {
+	/* standard M2M buffer descriptor */
+	struct v4l2_m2m_buffer	buf;
+
+	/* pointer to mesh configuration for processing */
+	struct imr_cfg		*cfg;
+};
+
+struct imr_q_data {
+	/* latched pixel format */
+	struct v4l2_pix_format	fmt;
+
+	/* current format flags */
+	u32			flags;
+};
+
+struct imr_format_info {
+	u32			fourcc;
+	u32			flags;
+};
+
+/* per-device data */
+struct imr_device {
+	struct device		*dev;
+	struct clk		*clock;
+	void __iomem		*mmio;
+	int			irq;
+	struct mutex		mutex;
+	spinlock_t		lock;
+
+	struct v4l2_device	v4l2_dev;
+	struct video_device	video_dev;
+	struct v4l2_m2m_dev	*m2m_dev;
+	void			*alloc_ctx;
+
+	/*
+	 * do we need that counter really?
+	 * framework counts fh structures for us - TBD
+	 */
+	int			refcount;
+
+	/* should we include media-dev? likely, no - TBD */
+};
+
+struct imr_point {
+	u16			x;
+	u16			y;
+};
+
+struct imr_rect {
+	struct imr_point	min;
+	struct imr_point	max;
+};
+
+/* per file-handle context */
+struct imr_ctx {
+	struct v4l2_fh		fh;
+	struct imr_device	*imr;
+	struct v4l2_m2m_ctx	*m2m_ctx;
+	struct imr_q_data	queue[2];
+
+	/* current job configuration */
+	struct imr_cfg		*cfg;
+
+	/* frame sequence counter */
+	u32			sequence;
+
+	/* composing parameters (in pixels) */
+	struct imr_rect		rect;
+
+	/* number of active configurations (debugging) */
+	u32			cfg_num;
+};
+
+/*******************************************************************************
+ * IMR registers
+ ******************************************************************************/
+
+#define IMR_CR			0x08
+#define IMR_SR			0x0C
+#define IMR_SRCR		0x10
+#define IMR_ICR			0x14
+#define IMR_IMR			0x18
+#define IMR_DLSP		0x1C
+#define IMR_DLPR		0x20
+#define IMR_DLSAR		0x30
+#define IMR_DSAR		0x34
+#define IMR_SSAR		0x38
+#define IMR_DSTR		0x3C
+#define IMR_SSTR		0x40
+#define IMR_DSOR		0x50
+#define IMR_CMRCR		0x54
+#define IMR_CMRCSR		0x58
+#define IMR_CMRCCR		0x5C
+#define IMR_TRIMR		0x60
+#define IMR_TRIMSR		0x64
+#define IMR_TRIMCR		0x68
+#define IMR_TRICR		0x6C
+#define IMR_UVDPOR		0x70
+#define IMR_SUSR		0x74
+#define IMR_SVSR		0x78
+#define IMR_XMINR		0x80
+#define IMR_YMINR		0x84
+#define IMR_XMAXR		0x88
+#define IMR_YMAXR		0x8C
+#define IMR_AMXSR		0x90
+#define IMR_AMYSR		0x94
+#define IMR_AMXOR		0x98
+#define IMR_AMYOR		0x9C
+#define IMR_CPDPOR		0xD0
+#define IMR_CMRCR2		0xE4
+#define IMR_CMRCSR2		0xE8
+#define IMR_CMRCCR2		0xEC
+
+#define IMR_CR_RS		BIT(0)
+#define IMR_CR_SWRST		BIT(15)
+
+#define IMR_SR_TRA		BIT(0)
+#define IMR_SR_IER		BIT(1)
+#define IMR_SR_INT		BIT(2)
+#define IMR_SR_REN		BIT(5)
+
+#define IMR_ICR_TRAENB		BIT(0)
+#define IMR_ICR_IERENB		BIT(1)
+#define IMR_ICR_INTENB		BIT(2)
+
+#define IMR_IMR_TRAM		BIT(0)
+#define IMR_IMR_IEM		BIT(1)
+#define IMR_IMR_INM		BIT(2)
+
+#define IMR_CMRCR_LUCE		BIT(1)
+#define IMR_CMRCR_CLCE		BIT(2)
+#define IMR_CMRCR_DUV_SHIFT	3
+#define IMR_CMRCR_DUV		GENMASK(4, 3)
+#define IMR_CMRCR_SUV_SHIFT	5
+#define IMR_CMRCR_SUV		GENMASK(6, 5)
+#define IMR_CMRCR_YISM		BIT(7)
+#define IMR_CMRCR_Y10		BIT(8)
+#define IMR_CMRCR_Y12		BIT(9)
+#define IMR_CMRCR_SY10		BIT(11)
+#define IMR_CMRCR_SY12		BIT(12)
+#define IMR_CMRCR_YCM		BIT(14)
+#define IMR_CMRCR_CP16E		BIT(15)
+
+#define IMR_TRIMR_TME		BIT(0)
+#define IMR_TRIMR_BFE		BIT(1)
+#define IMR_TRIMR_AUTODG	BIT(2)
+#define IMR_TRIMR_AUTOSG	BIT(3)
+#define IMR_TRIMR_TCM		BIT(6)
+
+#define IMR_TRICR_YCFORM	BIT(31)
+
+#define IMR_UVDPOR_UVDPO_SHIFT	0
+#define IMR_UVDPOR_UVDPO	GENMASK(2, 0)
+#define IMR_UVDPOR_DDP		BIT(8)
+
+#define IMR_SUSR_SVW_SHIFT	0
+#define IMR_SUSR_SVW		GENMASK(10, 0)
+#define IMR_SUSR_SUW_SHIFT	16
+#define IMR_SUSR_SUW		GENMASK(26, 16)
+
+#define IMR_CPDPOR_VRDPO_SHIFT	0
+#define IMR_CPDPOR_VRDPO	GENMASK(2, 0)
+#define IMR_CPDPOR_UBDPO_SHIFT	4
+#define IMR_CPDPOR_UBDPO	GENMASK(6, 4)
+#define IMR_CPDPOR_YLDPO_SHIFT	8
+#define IMR_CPDPOR_YLDPO	GENMASK(10, 8)
+
+#define IMR_CMRCR2_LUTE		BIT(0)
+#define IMR_CMRCR2_YUV422E	BIT(2)
+#define IMR_CMRCR2_YUV422FORM	BIT(5)
+#define IMR_CMRCR2_UVFORM	BIT(6)
+#define IMR_CMRCR2_TCTE		BIT(12)
+#define IMR_CMRCR2_DCTE		BIT(15)
+
+/*******************************************************************************
+ * Display list commands
+ ******************************************************************************/
+
+#define IMR_OP_NOP(n)		((0x80 << 24) | ((n) & 0xFFFF))
+#define IMR_OP_WTL(add, n)	((0x81 << 24) | ((((add) & 0x3FC) / 4) << 16) \
+				 | ((n) & 0xFFFF))
+#define IMR_OP_WTS(add, data)	((0x82 << 24) | ((((add) & 0x3FC) / 4) << 16) \
+				 | ((data) & 0xFFFF))
+#define IMR_OP_WTL2(add, n)	((0x83 << 24) | ((((add) & 0xFFFC) / 4) << 10) \
+				 | ((n) & 0x3FF))
+#define IMR_OP_SYNCM		 (0x86 << 24)
+#define IMR_OP_INT		 (0x88 << 24)
+#define IMR_OP_TRI(n)		((0x8A << 24) | ((n) & 0xFFFF))
+#define IMR_OP_GOSUB		 (0x8C << 24)
+#define IMR_OP_RET		 (0x8D << 24)
+#define IMR_OP_TRAP		 (0x8F << 24)
+
+/*******************************************************************************
+ * Auxiliary helpers
+ ******************************************************************************/
+
+static struct imr_ctx *fh_to_ctx(struct v4l2_fh *fh)
+{
+	return container_of(fh, struct imr_ctx, fh);
+}
+
+static struct imr_buffer *to_imr_buffer(struct vb2_v4l2_buffer *vbuf)
+{
+	struct v4l2_m2m_buffer *b = container_of(vbuf, struct v4l2_m2m_buffer,
+						 vb);
+
+	return container_of(b, struct imr_buffer, buf);
+}
+
+/*******************************************************************************
+ * Local constant definition
+ ******************************************************************************/
+
+#define IMR_F_Y8		BIT(0)
+#define IMR_F_Y10		BIT(1)
+#define IMR_F_Y12		BIT(2)
+#define IMR_F_UV8		BIT(3)
+#define IMR_F_UV10		BIT(4)
+#define IMR_F_UV12		BIT(5)
+#define IMR_F_PLANAR		BIT(6)
+#define IMR_F_INTERLEAVED	BIT(7)
+#define IMR_F_PLANES_MASK	(BIT(8) - 1)
+#define IMR_F_UV_SWAP		BIT(8)
+#define IMR_F_YUV_SWAP		BIT(9)
+
+/* get common planes bits */
+static u32 __imr_flags_common(u32 iflags, u32 oflags)
+{
+	return iflags & oflags & IMR_F_PLANES_MASK;
+}
+
+static const struct imr_format_info imr_lx4_formats[] = {
+	{
+		.fourcc	= V4L2_PIX_FMT_NV16,
+		.flags	= IMR_F_Y8 | IMR_F_UV8 | IMR_F_PLANAR,
+	},
+	{
+		.fourcc	= V4L2_PIX_FMT_NV61,
+		.flags	= IMR_F_Y8 | IMR_F_UV8 | IMR_F_PLANAR | IMR_F_UV_SWAP,
+	},
+	{
+		.fourcc	= V4L2_PIX_FMT_YUYV,
+		.flags	= IMR_F_Y8 | IMR_F_UV8,
+	},
+	{
+		.fourcc	= V4L2_PIX_FMT_UYVY,
+		.flags	= IMR_F_Y8 | IMR_F_UV8 | IMR_F_YUV_SWAP,
+	},
+	{
+		.fourcc	= V4L2_PIX_FMT_YVYU,
+		.flags	= IMR_F_Y8 | IMR_F_UV8 | IMR_F_UV_SWAP,
+	},
+	{
+		.fourcc	= V4L2_PIX_FMT_VYUY,
+		.flags	= IMR_F_Y8 | IMR_F_UV8 | IMR_F_UV_SWAP | IMR_F_YUV_SWAP,
+	},
+	{
+		.fourcc	= V4L2_PIX_FMT_GREY,
+		.flags	= IMR_F_Y8 | IMR_F_PLANAR,
+	},
+	{
+		.fourcc	= V4L2_PIX_FMT_Y10,
+		.flags	= IMR_F_Y8 | IMR_F_Y10 | IMR_F_PLANAR,
+	},
+	{
+		.fourcc	= V4L2_PIX_FMT_Y12,
+		.flags	= IMR_F_Y8 | IMR_F_Y10 | IMR_F_Y12 | IMR_F_PLANAR,
+	},
+	{
+		.fourcc	= V4L2_PIX_FMT_UV8,
+		.flags	= IMR_F_UV8 | IMR_F_PLANAR,
+	},
+};
+
+/* mesh configuration constructor */
+static struct imr_cfg *imr_cfg_create(struct imr_ctx *ctx,
+				      u32 dl_size, u32 dl_start)
+{
+	struct imr_device	*imr = ctx->imr;
+	struct imr_cfg		*cfg;
+
+	/* allocate configuration descriptor */
+	cfg = kmalloc(sizeof(*cfg), GFP_KERNEL);
+	if (!cfg)
+		return ERR_PTR(-ENOMEM);
+
+	/* allocate contiguous memory for a display list */
+	cfg->dl_vaddr = dma_alloc_writecombine(imr->dev, dl_size,
+					       &cfg->dl_dma_addr, GFP_KERNEL);
+	if (!cfg->dl_vaddr) {
+		v4l2_err(&imr->v4l2_dev,
+			 "failed to allocate %u bytes for a DL\n", dl_size);
+		kfree(cfg);
+		return ERR_PTR(-ENOMEM);
+	}
+
+	cfg->dl_size = dl_size;
+	cfg->dl_start_offset = dl_start;
+	cfg->refcount = 1;
+	cfg->id = ctx->sequence;
+
+	/* for debugging purposes, advance number of active configurations */
+	ctx->cfg_num++;
+
+	return cfg;
+}
+
+/* add reference to the current configuration */
+static struct imr_cfg *imr_cfg_ref(struct imr_ctx *ctx)
+{
+	struct imr_cfg *cfg = ctx->cfg;
+
+	BUG_ON(!cfg);
+	cfg->refcount++;
+	return cfg;
+}
+
+/* mesh configuration destructor */
+static void imr_cfg_unref(struct imr_ctx *ctx, struct imr_cfg *cfg)
+{
+	struct imr_device *imr = ctx->imr;
+
+	/* no atomicity is required as operation is locked with device mutex */
+	if (!cfg || --cfg->refcount)
+		return;
+
+	/* release memory allocated for a display list */
+	if (cfg->dl_vaddr)
+		dma_free_writecombine(imr->dev, cfg->dl_size, cfg->dl_vaddr,
+				      cfg->dl_dma_addr);
+
+	/* destroy the configuration structure */
+	kfree(cfg);
+
+	/* decrement number of active configurations (debugging) */
+	WARN_ON(!ctx->cfg_num--);
+}
+
+/*******************************************************************************
+ * Context processing queue
+ ******************************************************************************/
+
+static int imr_queue_setup(struct vb2_queue *vq,
+			   unsigned int *nbuffers, unsigned int *nplanes,
+			   unsigned int sizes[], struct device *alloc_devs[])
+{
+	struct imr_ctx		*ctx = vb2_get_drv_priv(vq);
+	struct imr_q_data	*q_data = &ctx->queue
+					[V4L2_TYPE_IS_OUTPUT(vq->type) ? 0 : 1];
+
+	if (*nplanes)
+		return sizes[0] < q_data->fmt.sizeimage ? -EINVAL : 0;
+
+	/* we use only single-plane formats */
+	*nplanes = 1;
+	sizes[0] = q_data->fmt.sizeimage;
+
+	return 0;
+}
+
+static int imr_buf_prepare(struct vb2_buffer *vb)
+{
+	struct vb2_v4l2_buffer	*vbuf = to_vb2_v4l2_buffer(vb);
+	struct vb2_queue	*q = vb->vb2_queue;
+	struct imr_ctx		*ctx = vb2_get_drv_priv(q);
+
+	WARN_ON_ONCE(!mutex_is_locked(&ctx->imr->mutex));
+
+	v4l2_dbg(3, debug, &ctx->imr->v4l2_dev,
+		 "%sput buffer <0x%08llx> prepared\n",
+		 q->is_output ? "in" : "out",
+		 (u64)vb2_dma_contig_plane_dma_addr(vb, 0));
+
+	/*
+	 * for input buffer, put current configuration pointer
+	 * (add reference)
+	 */
+	if (q->is_output)
+		to_imr_buffer(vbuf)->cfg = imr_cfg_ref(ctx);
+
+	return 0;
+}
+
+static void imr_buf_finish(struct vb2_buffer *vb)
+{
+	struct vb2_v4l2_buffer	*vbuf = to_vb2_v4l2_buffer(vb);
+	struct vb2_queue	*q = vb->vb2_queue;
+	struct imr_ctx		*ctx = vb2_get_drv_priv(q);
+
+	WARN_ON(!mutex_is_locked(&ctx->imr->mutex));
+
+	/* any special processing of completed buffer? - TBD */
+	v4l2_dbg(3, debug, &ctx->imr->v4l2_dev,
+		 "%sput buffer <0x%08llx> done\n", q->is_output ? "in" : "out",
+		 (u64)vb2_dma_contig_plane_dma_addr(vb, 0));
+
+	/* unref configuration pointer as needed */
+	if (q->is_output)
+		imr_cfg_unref(ctx, to_imr_buffer(vbuf)->cfg);
+}
+
+static void imr_buf_queue(struct vb2_buffer *vb)
+{
+	struct vb2_v4l2_buffer	*vbuf = to_vb2_v4l2_buffer(vb);
+	struct vb2_queue	*q = vb->vb2_queue;
+	struct imr_ctx		*ctx = vb2_get_drv_priv(q);
+
+	v4l2_dbg(3, debug, &ctx->imr->v4l2_dev,
+		 "%sput buffer <0x%08llx> queued\n",
+		 q->is_output ? "in" : "out",
+		 (u64)vb2_dma_contig_plane_dma_addr(vb, 0));
+
+	v4l2_m2m_buf_queue(ctx->m2m_ctx, vbuf);
+}
+
+static void imr_stop_streaming(struct vb2_queue *vq)
+{
+	struct imr_ctx		*ctx = vb2_get_drv_priv(vq);
+	unsigned long		flags;
+	struct vb2_v4l2_buffer	*vb;
+
+	spin_lock_irqsave(&ctx->imr->lock, flags);
+
+	/* purge all buffers from a queue */
+	if (V4L2_TYPE_IS_OUTPUT(vq->type)) {
+		while ((vb = v4l2_m2m_src_buf_remove(ctx->m2m_ctx)) != NULL)
+			v4l2_m2m_buf_done(vb, VB2_BUF_STATE_ERROR);
+	} else {
+		while ((vb = v4l2_m2m_dst_buf_remove(ctx->m2m_ctx)) != NULL)
+			v4l2_m2m_buf_done(vb, VB2_BUF_STATE_ERROR);
+	}
+
+	spin_unlock_irqrestore(&ctx->imr->lock, flags);
+
+	v4l2_dbg(1, debug, &ctx->imr->v4l2_dev, "%s streaming stopped\n",
+		 V4L2_TYPE_IS_OUTPUT(vq->type) ? "output" : "capture");
+}
+
+/* buffer queue operations */
+static struct vb2_ops imr_qops = {
+	.queue_setup	= imr_queue_setup,
+	.buf_prepare	= imr_buf_prepare,
+	.buf_finish	= imr_buf_finish,
+	.buf_queue	= imr_buf_queue,
+	.stop_streaming	= imr_stop_streaming,
+	.wait_prepare	= vb2_ops_wait_prepare,
+	.wait_finish	= vb2_ops_wait_finish,
+};
+
+/* M2M device processing queue initialization */
+static int imr_queue_init(void *priv, struct vb2_queue *src_vq,
+			  struct vb2_queue *dst_vq)
+{
+	struct imr_ctx	*ctx = priv;
+	int		ret;
+
+	memset(src_vq, 0, sizeof(*src_vq));
+	src_vq->type = V4L2_BUF_TYPE_VIDEO_OUTPUT;
+	src_vq->io_modes = VB2_MMAP | VB2_USERPTR | VB2_DMABUF;
+	src_vq->drv_priv = ctx;
+	src_vq->buf_struct_size = sizeof(struct imr_buffer);
+	src_vq->ops = &imr_qops;
+	src_vq->mem_ops = &vb2_dma_contig_memops;
+	src_vq->timestamp_flags = V4L2_BUF_FLAG_TIMESTAMP_MONOTONIC;
+	src_vq->lock = &ctx->imr->mutex;
+	src_vq->dev = ctx->imr->v4l2_dev.dev;
+	ret = vb2_queue_init(src_vq);
+	if (ret)
+		return ret;
+
+	memset(dst_vq, 0, sizeof(*dst_vq));
+	dst_vq->type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
+	dst_vq->io_modes = VB2_MMAP | VB2_USERPTR | VB2_DMABUF;
+	dst_vq->drv_priv = ctx;
+	dst_vq->buf_struct_size = sizeof(struct v4l2_m2m_buffer);
+	dst_vq->ops = &imr_qops;
+	dst_vq->mem_ops = &vb2_dma_contig_memops;
+	dst_vq->timestamp_flags = V4L2_BUF_FLAG_TIMESTAMP_MONOTONIC;
+	dst_vq->lock = &ctx->imr->mutex;
+	dst_vq->dev = ctx->imr->v4l2_dev.dev;
+	return vb2_queue_init(dst_vq);
+}
+
+/*******************************************************************************
+ * Operation type decoding helpers
+ ******************************************************************************/
+
+static u16 __imr_auto_sg_dg_tcm(u32 type)
+{
+	return	(type & IMR_MAP_AUTOSG ? IMR_TRIMR_AUTOSG :
+		(type & IMR_MAP_AUTODG ? IMR_TRIMR_AUTODG : 0)) |
+		(type & IMR_MAP_TCM ? IMR_TRIMR_TCM : 0);
+}
+
+static u16 __imr_uvdp(u32 type)
+{
+	return (__IMR_MAP_UVDPOR(type) << IMR_UVDPOR_UVDPO_SHIFT) |
+	       (type & IMR_MAP_DDP ? IMR_UVDPOR_DDP : 0);
+}
+
+static u16 __imr_cpdp(u32 type)
+{
+	return (__IMR_MAP_YLDPO(type) << IMR_CPDPOR_YLDPO_SHIFT) |
+	       (__IMR_MAP_UBDPO(type) << IMR_CPDPOR_UBDPO_SHIFT) |
+	       (__IMR_MAP_VRDPO(type) << IMR_CPDPOR_VRDPO_SHIFT);
+}
+
+static u16 __imr_luce(u32 type)
+{
+	return type & IMR_MAP_LUCE ? IMR_CMRCR_LUCE : 0;
+}
+
+static u16 __imr_clce(u32 type)
+{
+	return type & IMR_MAP_CLCE ? IMR_CMRCR_CLCE : 0;
+}
+
+/*******************************************************************************
+ * Type A (absolute coordinates of source/destination) mapping
+ ******************************************************************************/
+
+/* return size of the subroutine for type A mapping */
+static u32 imr_tri_type_a_get_length(struct imr_mesh *mesh, int item_size)
+{
+	return ((1 + mesh->columns * (2 * item_size / sizeof(u32))) *
+		(mesh->rows - 1) + 1) * sizeof(u32);
+}
+
+/* set a mesh rows * columns using absolute coordinates */
+static u32 *imr_tri_set_type_a(u32 *dl, void *map, struct imr_mesh *mesh,
+			       int item_size)
+{
+	int columns = mesh->columns;
+	int i, j;
+
+	/* convert lattice into set of stripes */
+	for (i = 0; i < mesh->rows - 1; i++) {
+		*dl++ = IMR_OP_TRI(2 * columns);
+		for (j = 0; j < columns; j++) {
+			memcpy(dl, map, item_size);
+			dl  += item_size / sizeof(u32);
+			memcpy(dl, map + columns * item_size, item_size);
+			dl  += item_size / sizeof(u32);
+			map += item_size;
+		}
+	}
+
+	*dl++ = IMR_OP_RET;
+	return dl;
+}
+
+/*******************************************************************************
+ * Type B mapping (automatically generated source or destination coordinates)
+ ******************************************************************************/
+
+/* calculate length of a type B mapping */
+static u32 imr_tri_type_b_get_length(struct imr_mesh *mesh, int item_size)
+{
+	return (3 + (2 + (mesh->columns * (2 * item_size / sizeof(u32))) *
+		     (mesh->rows - 1)) + 1) * sizeof(u32);
+}
+
+/* set an auto-generated mesh n * m for a source/destination */
+static u32 *imr_tri_set_type_b(u32 *dl, void *map, struct imr_mesh *mesh,
+			       int item_size)
+{
+	int columns = mesh->columns;
+	int i, j, y;
+
+	/* set mesh configuration */
+	*dl++ = IMR_OP_WTS(IMR_AMXSR, mesh->dx);
+	*dl++ = IMR_OP_WTS(IMR_AMYSR, mesh->dy);
+
+	/* origin by X coordinate is the same across all rows */
+	*dl++ = IMR_OP_WTS(IMR_AMXOR, mesh->x0);
+
+	/* convert lattice into set of stripes */
+	for (i = 0, y = mesh->y0; i < mesh->rows - 1; i++, y += mesh->dy) {
+		/* set origin by Y coordinate for a current row */
+		*dl++ = IMR_OP_WTS(IMR_AMYOR, y);
+		*dl++ = IMR_OP_TRI(2 * columns);
+		/* fill single row */
+		for (j = 0; j < columns; j++) {
+			memcpy(dl, map, item_size);
+			dl  += item_size / sizeof(u32);
+			memcpy(dl, map + columns * item_size, item_size);
+			dl  += item_size / sizeof(u32);
+			map += item_size;
+		}
+	}
+
+	*dl++ = IMR_OP_RET;
+	return dl;
+}
+
+/*******************************************************************************
+ * Type C mapping (vertex-buffer-object)
+ ******************************************************************************/
+
+/* calculate length of a type C mapping */
+static u32 imr_tri_type_c_get_length(struct imr_vbo *vbo, int item_size)
+{
+	return ((1 + 3 * item_size / sizeof(u32)) * vbo->num + 1) * sizeof(u32);
+}
+
+/* set a VBO mapping using absolute coordinates */
+static u32 *imr_tri_set_type_c(u32 *dl, void *map, struct imr_vbo *vbo,
+			       int item_size)
+{
+	int length = 3 * item_size;
+	int i;
+
+	/* prepare list of triangles to draw */
+	for (i = 0; i < vbo->num; i++) {
+		*dl++ = IMR_OP_TRI(3);
+		memcpy(dl, map, length);
+		dl  += length / sizeof(u32);
+		map += length;
+	}
+
+	*dl++ = IMR_OP_RET;
+	return dl;
+}
+
+/*******************************************************************************
+ * DL program creation
+ ******************************************************************************/
+
+/* return length of a DL main program */
+static u32 imr_dl_program_length(struct imr_ctx *ctx)
+{
+	u32 iflags = ctx->queue[0].flags;
+	u32 oflags = ctx->queue[1].flags;
+	u32 cflags = __imr_flags_common(iflags, oflags);
+
+	/* check if formats are compatible */
+	if (((iflags & IMR_F_PLANAR) && !(oflags & IMR_F_PLANAR)) || !cflags) {
+		v4l2_err(&ctx->imr->v4l2_dev,
+			 "formats are incompatible: if=%x, of=%x, cf=%x\n",
+			 iflags, oflags, cflags);
+		return 0;
+	}
+
+	/*
+	 * maximal possible length of the program is 27 32-bits words;
+	 * round up to 32
+	 */
+	return 32 << 2;
+}
+
+/* setup DL for Y/YUV planar/interleaved processing */
+static void imr_dl_program_setup(struct imr_ctx *ctx, struct imr_cfg *cfg,
+				 u32 type, u32 *dl, u32 subaddr)
+{
+	u32 iflags = ctx->queue[0].flags;
+	u32 oflags = ctx->queue[1].flags;
+	u32 cflags = __imr_flags_common(iflags, oflags);
+	u16 src_y_fmt = (iflags & IMR_F_Y12 ? IMR_CMRCR_SY12 :
+			 (iflags & IMR_F_Y10 ? IMR_CMRCR_SY10 : 0));
+	u16 src_uv_fmt = (iflags & IMR_F_UV12 ? 2 :
+			  (iflags & IMR_F_UV10 ? 1 : 0)) << IMR_CMRCR_SUV_SHIFT;
+	u16 dst_y_fmt = (cflags & IMR_F_Y12 ? IMR_CMRCR_Y12 :
+			 (cflags & IMR_F_Y10 ? IMR_CMRCR_Y10 : 0));
+	u16 dst_uv_fmt = (cflags & IMR_F_UV12 ? 2 :
+			  (cflags & IMR_F_UV10 ? 1 : 0)) << IMR_CMRCR_DUV_SHIFT;
+	int w = ctx->queue[0].fmt.width;
+	int h = ctx->queue[0].fmt.height;
+	int W = ctx->queue[1].fmt.width;
+	int H = ctx->queue[1].fmt.height;
+
+	v4l2_dbg(2, debug, &ctx->imr->v4l2_dev,
+		 "setup %ux%u -> %ux%u mapping (type=%x)\n", w, h, W, H, type);
+
+	/* set triangle mode register from user-supplied descriptor */
+	*dl++ = IMR_OP_WTS(IMR_TRIMCR, 0x004F);
+
+	/* set automatic source/destination coordinates generation flags */
+	*dl++ = IMR_OP_WTS(IMR_TRIMSR, __imr_auto_sg_dg_tcm(type) |
+			   IMR_TRIMR_BFE | IMR_TRIMR_TME);
+
+	/* set source/destination coordinate precision */
+	*dl++ = IMR_OP_WTS(IMR_UVDPOR, __imr_uvdp(type));
+
+	/* set luminance/chromacity correction parameters precision */
+	*dl++ = IMR_OP_WTS(IMR_CPDPOR, __imr_cpdp(type));
+
+	/* reset rendering mode registers */
+	*dl++ = IMR_OP_WTS(IMR_CMRCCR,  0xDBFE);
+	*dl++ = IMR_OP_WTS(IMR_CMRCCR2, 0x9065);
+
+	/* set source/destination addresses of Y/UV plane */
+	*dl++ = IMR_OP_WTL(IMR_DSAR, 2);
+	cfg->dst_pa_ptr[0] = dl++;
+	cfg->src_pa_ptr[0] = dl++;
+
+	/* select planar/interleaved mode basing on input format */
+	if (iflags & IMR_F_PLANAR) {
+		/* planar input means planar output; set Y plane precision */
+		if (cflags & IMR_F_Y8) {
+			/*
+			 * setup Y plane processing: YCM=0, SY/DY=xx,
+			 * SUV/DUV=0
+			 */
+			*dl++ = IMR_OP_WTS(IMR_CMRCSR, src_y_fmt | src_uv_fmt |
+					   dst_y_fmt | dst_uv_fmt |
+					   __imr_luce(type));
+
+			/*
+			 * set source/destination strides basing on Y plane
+			 * precision
+			 */
+			*dl++ = IMR_OP_WTS(IMR_DSTR,
+					   W << (cflags & IMR_F_Y10 ? 1 : 0));
+			*dl++ = IMR_OP_WTS(IMR_SSTR,
+					   w << (iflags & IMR_F_Y10 ? 1 : 0));
+		} else {
+			/* setup UV plane processing only */
+			*dl++ = IMR_OP_WTS(IMR_CMRCSR, IMR_CMRCR_YCM |
+					   src_uv_fmt | dst_uv_fmt |
+					   __imr_clce(type));
+
+			/*
+			 * set source/destination strides basing on UV plane
+			 * precision
+			 */
+			*dl++ = IMR_OP_WTS(IMR_DSTR,
+					   W << (cflags & IMR_F_UV10 ? 1 : 0));
+			*dl++ = IMR_OP_WTS(IMR_SSTR,
+					   w << (iflags & IMR_F_UV10 ? 1 : 0));
+		}
+	} else {
+		u16 src_fmt = (iflags & IMR_F_UV_SWAP ? IMR_CMRCR2_UVFORM : 0) |
+			      (iflags & IMR_F_YUV_SWAP ?
+			       IMR_CMRCR2_YUV422FORM : 0);
+		u32 dst_fmt = (oflags & IMR_F_YUV_SWAP ? IMR_TRICR_YCFORM : 0);
+
+		/* interleaved input; output is either interleaved or planar */
+		*dl++ = IMR_OP_WTS(IMR_CMRCSR2, IMR_CMRCR2_YUV422E | src_fmt);
+
+		/* destination is always YUYV or UYVY */
+		*dl++ = IMR_OP_WTL(IMR_TRICR, 1);
+		*dl++ = dst_fmt;
+
+		/* set precision of Y/UV planes and required correction */
+		*dl++ = IMR_OP_WTS(IMR_CMRCSR, src_y_fmt | src_uv_fmt |
+				   dst_y_fmt | dst_uv_fmt | __imr_clce(type) |
+				   __imr_luce(type));
+
+		/* set source stride basing on precision (2 or 4 bytes/pixel) */
+		*dl++ = IMR_OP_WTS(IMR_SSTR, w << (iflags & IMR_F_Y10 ? 2 : 1));
+
+		/* if output is planar, put the offset value */
+		if (oflags & IMR_F_PLANAR) {
+			/* specify offset of a destination UV plane */
+			*dl++ = IMR_OP_WTL(IMR_DSOR, 1);
+			*dl++ = W * H;
+
+			/*
+			 * destination stride is 1 or 2 bytes/pixel
+			 * (same for both Y and UV planes)
+			 */
+			*dl++ = IMR_OP_WTS(IMR_DSTR,
+					   W << (cflags & IMR_F_Y10 ? 1 : 0));
+		} else {
+			/*
+			 * destination stride if 2 or 4 bytes/pixel
+			 * (Y and UV planes interleaved)
+			 */
+			*dl++ = IMR_OP_WTS(IMR_DSTR,
+					   W << (cflags & IMR_F_Y10 ? 2 : 1));
+		}
+	}
+
+	/*
+	 * set source width/height of Y/UV plane
+	 * (for Y plane upper part of SUSR is ignored)
+	 */
+	*dl++ = IMR_OP_WTL(IMR_SUSR, 2);
+	*dl++ = ((w - 2) << IMR_SUSR_SUW_SHIFT) |
+		((w - 1) << IMR_SUSR_SVW_SHIFT);
+	*dl++ = h - 1;
+
+	/* invoke subroutine for drawing triangles */
+	*dl++ = IMR_OP_GOSUB;
+	*dl++ = subaddr;
+
+	/* if we have a planar output with both Y and UV planes available */
+	if ((cflags & (IMR_F_PLANAR | IMR_F_Y8 | IMR_F_UV8)) ==
+	    (IMR_F_PLANAR | IMR_F_Y8 | IMR_F_UV8)) {
+		/* select UV plane processing mode; put sync before switching */
+		*dl++ = IMR_OP_SYNCM;
+
+		/* setup UV-plane source/destination addresses */
+		*dl++ = IMR_OP_WTL(IMR_DSAR, 2);
+		cfg->dst_pa_ptr[1] = dl++;
+		cfg->src_pa_ptr[1] = dl++;
+
+		/* select correction mode */
+		*dl++ = IMR_OP_WTS(IMR_CMRCSR, IMR_CMRCR_YCM |
+				   __imr_clce(type));
+
+		/* luminance correction bit must be cleared (if it was set) */
+		*dl++ = IMR_OP_WTS(IMR_CMRCCR, IMR_CMRCR_LUCE);
+
+		/* draw triangles */
+		*dl++ = IMR_OP_GOSUB;
+		*dl++ = subaddr;
+	} else {
+		/*
+		 * clear pointers to the source/destination UV-planes addresses
+		 */
+		cfg->src_pa_ptr[1] = cfg->dst_pa_ptr[1] = NULL;
+	}
+
+	/* signal completion of the operation */
+	*dl++ = IMR_OP_SYNCM;
+	*dl++ = IMR_OP_TRAP;
+}
+
+/*******************************************************************************
+ * Mapping specification processing
+ ******************************************************************************/
+
+/* set mapping data (function called with video device lock held) */
+static int imr_ioctl_map(struct imr_ctx *ctx, struct imr_map_desc *desc)
+{
+	struct imr_device	*imr = ctx->imr;
+	struct imr_mesh		*mesh;
+	struct imr_vbo		*vbo;
+	struct imr_cfg		*cfg;
+	void			*buf, *map;
+	u32                     type;
+	u32			length, item_size;
+	u32			tri_length;
+	void			*dl_vaddr;
+	u32			dl_size;
+	u32			dl_start_offset;
+	dma_addr_t		dl_dma_addr;
+	int			ret = 0;
+
+	/* read remainder of data into temporary buffer */
+	length = desc->size;
+	buf  = memdup_user((void __user *)(unsigned long)desc->data, length);
+	if (IS_ERR(buf)) {
+		v4l2_err(&imr->v4l2_dev,
+			 "failed to copy %u bytes of mapping specification\n",
+			 length);
+		return PTR_ERR(buf);
+	}
+
+	/* mesh item size calculation */
+	type = desc->type;
+	item_size = (type & IMR_MAP_LUCE ? 4 : 0) +
+		    (type & IMR_MAP_CLCE ? 4 : 0);
+
+	/* calculate the length of a display list */
+	if (type & IMR_MAP_MESH) {
+		/* assure we have proper mesh descriptor */
+		if (length < sizeof(struct imr_mesh)) {
+			v4l2_err(&imr->v4l2_dev,
+				 "invalid mesh specification size: %u\n",
+				 length);
+			ret = -EINVAL;
+			goto out;
+		}
+
+		mesh = (struct imr_mesh *)buf;
+		length -= sizeof(struct imr_mesh);
+		map = buf + sizeof(struct imr_mesh);
+
+		if (type & (IMR_MAP_AUTODG | IMR_MAP_AUTOSG)) {
+			/*
+			 * mapping is given using automatic generation pattern;
+			 * source/destination vertex size is 4 bytes
+			 */
+			item_size += 4;
+
+			/* calculate size of triangles drawing subroutine */
+			tri_length = imr_tri_type_b_get_length(mesh, item_size);
+		} else {
+			/*
+			 * mapping is done with absolute coordinates;
+			 * source/destination vertex size is 8 bytes
+			 */
+			item_size += 8;
+
+			/* calculate size of triangles drawing subroutine */
+			tri_length = imr_tri_type_a_get_length(mesh, item_size);
+		}
+
+		/* check size */
+		if (mesh->rows * mesh->columns * item_size != length) {
+			v4l2_err(&imr->v4l2_dev,
+				 "invalid mesh size: %u*%u*%u != %u\n",
+				 mesh->rows, mesh->columns, item_size,
+				 length);
+			ret = -EINVAL;
+			goto out;
+		}
+	} else {
+		/* assure we have proper VBO descriptor */
+		if (length < sizeof(struct imr_vbo)) {
+			v4l2_err(&imr->v4l2_dev,
+				 "invalid vbo specification size: %u\n",
+				 length);
+			ret = -EINVAL;
+			goto out;
+		}
+
+		/* make sure there is no automatically generation flags */
+		if (type & (IMR_MAP_AUTODG | IMR_MAP_AUTOSG)) {
+			v4l2_err(&imr->v4l2_dev,
+				 "invalid auto-dg/sg flags: 0x%x\n", type);
+			ret = -EINVAL;
+			goto out;
+		}
+
+		vbo = (struct imr_vbo *)buf;
+		length -= sizeof(struct imr_vbo);
+		map = buf + sizeof(struct imr_vbo);
+
+		/* vertex is given with absolute coordinates */
+		item_size += 8;
+
+		/* check that the length is sane */
+		if (vbo->num * 3 * item_size != length) {
+			v4l2_err(&imr->v4l2_dev,
+				 "invalid vbo size: %u*%u*3 != %u\n", vbo->num,
+				 item_size, length);
+			ret = -EINVAL;
+			goto out;
+		}
+
+		/* calculate size of triangles drawing subroutine */
+		tri_length = imr_tri_type_c_get_length(vbo, item_size);
+	}
+
+	/* DL main program shall start on 8-byte aligned address */
+	dl_start_offset = ALIGN(tri_length, 8);
+
+	/* calculate main routine length */
+	dl_size = imr_dl_program_length(ctx);
+	if (!dl_size) {
+		v4l2_err(&imr->v4l2_dev, "format configuration error\n");
+		ret = -EINVAL;
+		goto out;
+	}
+
+	/* we use a single display list, with TRI subroutine prepending MAIN */
+	dl_size += dl_start_offset;
+
+	/* unref current configuration (will not be used by subsequent jobs) */
+	imr_cfg_unref(ctx, ctx->cfg);
+
+	/* create new configuration */
+	cfg = imr_cfg_create(ctx, dl_size, dl_start_offset);
+	if (IS_ERR(cfg)) {
+		ret = PTR_ERR(cfg);
+		ctx->cfg = NULL;
+		v4l2_err(&imr->v4l2_dev,
+			 "failed to create configuration: %d\n", ret);
+		goto out;
+	}
+	ctx->cfg = cfg;
+
+	/* get pointer to the new display list */
+	dl_vaddr = cfg->dl_vaddr;
+	dl_dma_addr = cfg->dl_dma_addr;
+
+	/* prepare a triangles drawing subroutine */
+	if (type & IMR_MAP_MESH) {
+		if (type & (IMR_MAP_AUTOSG | IMR_MAP_AUTODG))
+			imr_tri_set_type_b(dl_vaddr, map, mesh, item_size);
+		else
+			imr_tri_set_type_a(dl_vaddr, map, mesh, item_size);
+	} else {
+		imr_tri_set_type_c(dl_vaddr, map, vbo, item_size);
+	}
+
+	/* prepare main DL program */
+	imr_dl_program_setup(ctx, cfg, type, dl_vaddr + dl_start_offset,
+			     (u32)dl_dma_addr);
+
+	/* update cropping parameters */
+	cfg->dst_subpixel = (type & IMR_MAP_DDP ? 2 : 0);
+
+	/* display list updated successfully */
+	v4l2_dbg(2, debug, &ctx->imr->v4l2_dev,
+		 "display-list created: #%u[%08X]:%u[%u]\n",
+		 cfg->id, (u32)dl_dma_addr, dl_size, dl_start_offset);
+
+	if (debug >= 4)
+		print_hex_dump_bytes("DL-", DUMP_PREFIX_OFFSET,
+				     dl_vaddr + dl_start_offset,
+				     dl_size  - dl_start_offset);
+
+out:
+	/* release interim buffer */
+	kfree(buf);
+
+	return ret;
+}
+
+/*******************************************************************************
+ * V4L2 I/O controls
+ ******************************************************************************/
+
+/* test if a format is supported */
+static int __imr_try_fmt(struct imr_ctx *ctx, struct v4l2_format *f)
+{
+	struct v4l2_pix_format	*pix = &f->fmt.pix;
+	u32			fourcc = pix->pixelformat;
+	int			i;
+
+	/*
+	 * both output and capture interface have the same set of
+	 * supported formats
+	 */
+	for (i = 0; i < ARRAY_SIZE(imr_lx4_formats); i++) {
+		if (fourcc == imr_lx4_formats[i].fourcc) {
+			/* fix up format specification as needed */
+			pix->field = V4L2_FIELD_NONE;
+
+			v4l2_dbg(1, debug, &ctx->imr->v4l2_dev,
+				 "format request: '%c%c%c%c', %dx%d\n",
+				 (fourcc >> 0)	& 0xff,	(fourcc >> 8)  & 0xff,
+				 (fourcc >> 16) & 0xff, (fourcc >> 24) & 0xff,
+				 pix->width, pix->height);
+
+			/* verify source/destination image dimensions */
+			if (V4L2_TYPE_IS_OUTPUT(f->type))
+				v4l_bound_align_image(&pix->width, 128, 2048, 7,
+						      &pix->height,  1, 2048, 0,
+						      0);
+			else
+				v4l_bound_align_image(&pix->width,  64, 2048, 6,
+						      &pix->height,  1, 2048, 0,
+						      0);
+
+			return i;
+		}
+	}
+
+	v4l2_err(&ctx->imr->v4l2_dev,
+		 "unsupported format request: '%c%c%c%c'\n",
+		 (fourcc >> 0)  & 0xff, (fourcc >> 8)  & 0xff,
+		 (fourcc >> 16) & 0xff, (fourcc >> 24) & 0xff);
+
+	return -EINVAL;
+}
+
+/* capabilities query */
+static int imr_querycap(struct file *file, void *priv,
+			struct v4l2_capability *cap)
+{
+	strlcpy(cap->driver, DRV_NAME, sizeof(cap->driver));
+	strlcpy(cap->card, DRV_NAME, sizeof(cap->card));
+	strlcpy(cap->bus_info, DRV_NAME, sizeof(cap->bus_info));
+
+	return 0;
+}
+
+/* enumerate supported formats */
+static int imr_enum_fmt(struct file *file, void *priv, struct v4l2_fmtdesc *f)
+{
+	/* no distinction between output/capture formats */
+	if (f->index < ARRAY_SIZE(imr_lx4_formats)) {
+		f->pixelformat = imr_lx4_formats[f->index].fourcc;
+		return 0;
+	}
+
+	return -EINVAL;
+}
+
+/* retrieve current queue format; operation is locked? */
+static int imr_g_fmt(struct file *file, void *priv, struct v4l2_format *f)
+{
+	struct imr_ctx		*ctx = fh_to_ctx(priv);
+	struct imr_q_data	*q_data;
+	struct vb2_queue	*vq;
+
+	vq = v4l2_m2m_get_vq(ctx->m2m_ctx, f->type);
+	if (!vq)
+		return -EINVAL;
+
+	q_data = &ctx->queue[V4L2_TYPE_IS_OUTPUT(f->type) ? 0 : 1];
+
+	/* processing is locked? TBD */
+	f->fmt.pix = q_data->fmt;
+
+	return 0;
+}
+
+/* test particular format; operation is not locked */
+static int imr_try_fmt(struct file *file, void *priv, struct v4l2_format *f)
+{
+	struct imr_ctx		*ctx = fh_to_ctx(priv);
+	struct vb2_queue	*vq;
+
+	/* make sure we have a queue of particular type */
+	vq = v4l2_m2m_get_vq(ctx->m2m_ctx, f->type);
+	if (!vq)
+		return -EINVAL;
+
+	/* test if format is supported (adjust as appropriate) */
+	return __imr_try_fmt(ctx, f) >= 0 ? 0 : -EINVAL;
+}
+
+/* apply queue format; operation is locked? */
+static int imr_s_fmt(struct file *file, void *priv, struct v4l2_format *f)
+{
+	struct imr_ctx		*ctx = fh_to_ctx(priv);
+	struct imr_q_data	*q_data;
+	struct vb2_queue	*vq;
+	int			i;
+
+	vq = v4l2_m2m_get_vq(ctx->m2m_ctx, f->type);
+	if (!vq)
+		return -EINVAL;
+
+	/* check if queue is busy */
+	if (vb2_is_busy(vq))
+		return -EBUSY;
+
+	/* test if format is supported (adjust as appropriate) */
+	i = __imr_try_fmt(ctx, f);
+	if (i < 0)
+		return -EINVAL;
+
+	/* format is supported; save current format in a queue-specific data */
+	q_data = &ctx->queue[V4L2_TYPE_IS_OUTPUT(f->type) ? 0 : 1];
+
+	/* processing is locked? TBD */
+	q_data->fmt = f->fmt.pix;
+	q_data->flags = imr_lx4_formats[i].flags;
+
+	/* set default compose factors */
+	if (!V4L2_TYPE_IS_OUTPUT(f->type)) {
+		ctx->rect.min.x = 0;
+		ctx->rect.min.y = f->fmt.pix.width - 1;
+		ctx->rect.max.x = 0;
+		ctx->rect.max.y = f->fmt.pix.height - 1;
+	}
+
+	return 0;
+}
+
+static int imr_qbuf(struct file *file, void *priv, struct v4l2_buffer *buf)
+{
+	struct imr_ctx *ctx = fh_to_ctx(priv);
+
+	/* operation is protected with a queue lock */
+	WARN_ON(!mutex_is_locked(&ctx->imr->mutex));
+
+	/* verify the configuration is complete */
+	if (!ctx->cfg) {
+		v4l2_err(&ctx->imr->v4l2_dev,
+			 "stream configuration is not complete\n");
+		return -EINVAL;
+	}
+
+	return v4l2_m2m_qbuf(file, ctx->m2m_ctx, buf);
+}
+
+static int imr_g_selection(struct file *file, void *priv,
+			   struct v4l2_selection *s)
+{
+	struct imr_ctx		*ctx = fh_to_ctx(priv);
+	struct imr_q_data	*q_data = &ctx->queue[1];
+
+	if (s->type != V4L2_BUF_TYPE_VIDEO_CAPTURE)
+		return -EINVAL;
+
+	switch (s->target) {
+	case V4L2_SEL_TGT_COMPOSE_BOUNDS:
+	case V4L2_SEL_TGT_COMPOSE_DEFAULT:
+		s->r.left = s->r.top = 0;
+		s->r.width  = q_data->fmt.width;
+		s->r.height = q_data->fmt.height;
+		break;
+	case V4L2_SEL_TGT_COMPOSE:
+		s->r.left = ctx->rect.min.x;
+		s->r.top  = ctx->rect.min.y;
+		s->r.width  = ctx->rect.max.x - ctx->rect.min.x + 1;
+		s->r.height = ctx->rect.max.y - ctx->rect.min.y + 1;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static int imr_s_selection(struct file *file, void *priv,
+			   struct v4l2_selection *s)
+{
+	struct imr_ctx	*ctx = fh_to_ctx(priv);
+	struct imr_q_data *q_data = &ctx->queue[1];
+	struct v4l2_rect r = s->r;
+	struct v4l2_rect max_rect;
+
+	if (s->type != V4L2_BUF_TYPE_VIDEO_CAPTURE)
+		return -EINVAL;
+
+	switch (s->target) {
+	case V4L2_SEL_TGT_COMPOSE:
+		/* Make sure compose rect fits inside output format */
+		max_rect.top = max_rect.left = 0;
+		max_rect.width  = q_data->fmt.width;
+		max_rect.height = q_data->fmt.height;
+		v4l2_rect_map_inside(&r, &max_rect);
+
+		/* subpixel resolution of output buffer is not counted here */
+		ctx->rect.min.x = r.left;
+		ctx->rect.min.y = r.top;
+		ctx->rect.max.x = r.left + r.width  - 1;
+		ctx->rect.max.y = r.top  + r.height - 1;
+
+		s->r = r;
+		return 0;
+	default:
+		return -EINVAL;
+	}
+}
+
+/* customized I/O control processing */
+static long imr_default(struct file *file, void *fh, bool valid_prio,
+			unsigned int cmd,  void *arg)
+{
+	struct imr_ctx *ctx = fh_to_ctx(fh);
+
+	switch (cmd) {
+	case VIDIOC_IMR_MESH:
+		/* set mesh data */
+		return imr_ioctl_map(ctx, arg);
+
+	default:
+		return -ENOTTY;
+	}
+}
+
+static const struct v4l2_ioctl_ops imr_ioctl_ops = {
+	.vidioc_querycap		= imr_querycap,
+
+	.vidioc_enum_fmt_vid_cap	= imr_enum_fmt,
+	.vidioc_enum_fmt_vid_out	= imr_enum_fmt,
+	.vidioc_g_fmt_vid_cap		= imr_g_fmt,
+	.vidioc_g_fmt_vid_out		= imr_g_fmt,
+	.vidioc_try_fmt_vid_cap		= imr_try_fmt,
+	.vidioc_try_fmt_vid_out		= imr_try_fmt,
+	.vidioc_s_fmt_vid_cap		= imr_s_fmt,
+	.vidioc_s_fmt_vid_out		= imr_s_fmt,
+
+	.vidioc_reqbufs			= v4l2_m2m_ioctl_reqbufs,
+	.vidioc_create_bufs		= v4l2_m2m_ioctl_create_bufs,
+	.vidioc_querybuf		= v4l2_m2m_ioctl_querybuf,
+	.vidioc_qbuf			= imr_qbuf,
+	.vidioc_dqbuf			= v4l2_m2m_ioctl_dqbuf,
+	.vidioc_prepare_buf		= v4l2_m2m_ioctl_prepare_buf,
+	.vidioc_expbuf			= v4l2_m2m_ioctl_expbuf,
+	.vidioc_streamon		= v4l2_m2m_ioctl_streamon,
+	.vidioc_streamoff		= v4l2_m2m_ioctl_streamoff,
+
+	.vidioc_g_selection		= imr_g_selection,
+	.vidioc_s_selection		= imr_s_selection,
+
+	.vidioc_default			= imr_default,
+};
+
+/*******************************************************************************
+ * Generic device file operations
+ ******************************************************************************/
+
+static int imr_open(struct file *file)
+{
+	struct imr_device	*imr = video_drvdata(file);
+	struct video_device	*vfd = video_devdata(file);
+	struct imr_ctx		*ctx;
+	int			ret;
+
+	/* allocate processing context associated with given instance */
+	ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
+	if (!ctx)
+		return -ENOMEM;
+
+	/* initialize per-file-handle structure */
+	v4l2_fh_init(&ctx->fh, vfd);
+	file->private_data = &ctx->fh;
+	v4l2_fh_add(&ctx->fh);
+
+	/* set default source/destination formats - need that? */
+	ctx->imr = imr;
+	ctx->queue[0].fmt.pixelformat = V4L2_PIX_FMT_UYVY;
+	ctx->queue[1].fmt.pixelformat = V4L2_PIX_FMT_UYVY;
+
+	/* set default cropping parameters */
+	ctx->rect.max.x = ctx->rect.max.y = 0x3FF;
+
+	/* initialize M2M processing context */
+	ctx->m2m_ctx = v4l2_m2m_ctx_init(imr->m2m_dev, ctx, imr_queue_init);
+	if (IS_ERR(ctx->m2m_ctx)) {
+		ret = PTR_ERR(ctx->m2m_ctx);
+		goto v4l_prepare_rollback;
+	}
+
+	/* lock access to global device data */
+	if (mutex_lock_interruptible(&imr->mutex)) {
+		ret = -ERESTARTSYS;
+		goto v4l_prepare_rollback;
+	}
+
+	/* bring up device as needed */
+	if (imr->refcount == 0) {
+		ret = clk_prepare_enable(imr->clock);
+		if (ret < 0)
+			goto device_prepare_rollback;
+	}
+
+	imr->refcount++;
+
+	mutex_unlock(&imr->mutex);
+
+	v4l2_dbg(1, debug, &imr->v4l2_dev, "IMR device opened (refcount=%u)\n",
+		 imr->refcount);
+
+	return 0;
+
+device_prepare_rollback:
+	/* unlock global device data */
+	mutex_unlock(&imr->mutex);
+
+v4l_prepare_rollback:
+	/* destroy context */
+	v4l2_fh_del(&ctx->fh);
+	v4l2_fh_exit(&ctx->fh);
+	kfree(ctx);
+
+	return ret;
+}
+
+static int imr_release(struct file *file)
+{
+	struct imr_ctx		*ctx = fh_to_ctx(file->private_data);
+	struct imr_device	*imr = video_drvdata(file);
+
+	/* I don't need to get a device scope lock here really - TBD */
+	mutex_lock(&imr->mutex);
+
+	/* destroy M2M device processing context */
+	v4l2_m2m_ctx_release(ctx->m2m_ctx);
+	v4l2_fh_del(&ctx->fh);
+	v4l2_fh_exit(&ctx->fh);
+
+	/* drop active configuration as needed */
+	imr_cfg_unref(ctx, ctx->cfg);
+
+	/* make sure there are no more active configs */
+	WARN_ON(ctx->cfg_num);
+
+	/* destroy context data */
+	kfree(ctx);
+
+	/* disable hardware operation */
+	if (--imr->refcount == 0)
+		clk_disable_unprepare(imr->clock);
+
+	mutex_unlock(&imr->mutex);
+
+	v4l2_dbg(1, debug, &imr->v4l2_dev, "closed device instance\n");
+
+	return 0;
+}
+
+static unsigned int imr_poll(struct file *file, struct poll_table_struct *wait)
+{
+	struct imr_ctx		*ctx = fh_to_ctx(file->private_data);
+	struct imr_device	*imr = video_drvdata(file);
+	unsigned int		res;
+
+	if (mutex_lock_interruptible(&imr->mutex))
+		return -ERESTARTSYS;
+
+	res = v4l2_m2m_poll(file, ctx->m2m_ctx, wait);
+	mutex_unlock(&imr->mutex);
+
+	return res;
+}
+
+static int imr_mmap(struct file *file, struct vm_area_struct *vma)
+{
+	struct imr_device	*imr = video_drvdata(file);
+	struct imr_ctx		*ctx = fh_to_ctx(file->private_data);
+	int			ret;
+
+	/* should we protect all M2M operations with mutex? - TBD */
+	if (mutex_lock_interruptible(&imr->mutex))
+		return -ERESTARTSYS;
+
+	ret = v4l2_m2m_mmap(file, ctx->m2m_ctx, vma);
+
+	mutex_unlock(&imr->mutex);
+
+	return ret;
+}
+
+static const struct v4l2_file_operations imr_fops = {
+	.owner		= THIS_MODULE,
+	.open		= imr_open,
+	.release	= imr_release,
+	.poll		= imr_poll,
+	.mmap		= imr_mmap,
+	.unlocked_ioctl	= video_ioctl2,
+};
+
+/*******************************************************************************
+ * M2M device interface
+ ******************************************************************************/
+
+/* job execution function */
+static void imr_device_run(void *priv)
+{
+	struct imr_ctx		*ctx = priv;
+	struct imr_device	*imr = ctx->imr;
+	struct vb2_buffer	*src_buf, *dst_buf;
+	u32			src_addr,  dst_addr;
+	unsigned long		flags;
+	struct imr_cfg		*cfg;
+
+	v4l2_dbg(3, debug, &imr->v4l2_dev, "run next job...\n");
+
+	/* protect access to internal device state */
+	spin_lock_irqsave(&imr->lock, flags);
+
+	/* retrieve input/output buffers */
+	src_buf = v4l2_m2m_next_src_buf(ctx->m2m_ctx);
+	dst_buf = v4l2_m2m_next_dst_buf(ctx->m2m_ctx);
+
+	/* take configuration pointer associated with input buffer */
+	cfg = to_imr_buffer(to_vb2_v4l2_buffer(src_buf))->cfg;
+
+	/* cancel software reset state as needed */
+	iowrite32(0, imr->mmio + IMR_CR);
+
+	/* set composing data with respect to destination subpixel mode */
+	iowrite32(ctx->rect.min.x << cfg->dst_subpixel, imr->mmio + IMR_XMINR);
+	iowrite32(ctx->rect.min.y << cfg->dst_subpixel, imr->mmio + IMR_YMINR);
+	iowrite32(ctx->rect.max.x << cfg->dst_subpixel, imr->mmio + IMR_XMAXR);
+	iowrite32(ctx->rect.max.y << cfg->dst_subpixel, imr->mmio + IMR_YMAXR);
+
+	/*
+	 * adjust source/destination parameters of the program
+	 * (interleaved/semiplanar)
+	 */
+	*cfg->src_pa_ptr[0] = src_addr =
+		(u32)vb2_dma_contig_plane_dma_addr(src_buf, 0);
+	*cfg->dst_pa_ptr[0] = dst_addr =
+		(u32)vb2_dma_contig_plane_dma_addr(dst_buf, 0);
+
+	/* adjust source/destination parameters of the UV plane as needed */
+	if (cfg->src_pa_ptr[1] && cfg->dst_pa_ptr[1]) {
+		*cfg->src_pa_ptr[1] = src_addr +
+			ctx->queue[0].fmt.width * ctx->queue[0].fmt.height;
+		*cfg->dst_pa_ptr[1] = dst_addr +
+			ctx->queue[1].fmt.width * ctx->queue[1].fmt.height;
+	}
+
+	v4l2_dbg(3, debug, &imr->v4l2_dev,
+		 "process buffer-pair 0x%08x:0x%08x\n",
+		 *cfg->src_pa_ptr[0], *cfg->dst_pa_ptr[0]);
+
+	/* force clearing of the status register bits */
+	iowrite32(IMR_SR_TRA | IMR_SR_IER | IMR_SR_INT, imr->mmio + IMR_SRCR);
+
+	/* unmask/enable interrupts */
+	iowrite32(ioread32(imr->mmio + IMR_ICR) |
+		  (IMR_ICR_TRAENB | IMR_ICR_IERENB | IMR_ICR_INTENB),
+		  imr->mmio + IMR_ICR);
+	iowrite32(ioread32(imr->mmio + IMR_IMR) &
+		  ~(IMR_IMR_TRAM | IMR_IMR_IEM | IMR_IMR_INM),
+		  imr->mmio + IMR_IMR);
+
+	/* set display list address */
+	iowrite32(cfg->dl_dma_addr + cfg->dl_start_offset,
+		  imr->mmio + IMR_DLSAR);
+
+	/*
+	 * explicitly flush any pending write operations
+	 * (don't need that, I guess)
+	 */
+	wmb();
+
+	/* start rendering operation */
+	iowrite32(IMR_CR_RS, imr->mmio + IMR_CR);
+
+	/* timestamp input buffer */
+	src_buf->timestamp = ktime_get_ns();
+
+	/* unlock device access */
+	spin_unlock_irqrestore(&imr->lock, flags);
+
+	v4l2_dbg(1, debug, &imr->v4l2_dev,
+		 "rendering started: status=%x, DLSAR=0x%08x, DLPR=0x%08x\n",
+		 ioread32(imr->mmio + IMR_SR), ioread32(imr->mmio + IMR_DLSAR),
+		 ioread32(imr->mmio + IMR_DLPR));
+}
+
+/* check whether a job is ready for execution */
+static int imr_job_ready(void *priv)
+{
+	/* no specific requirements on the job readiness */
+	return 1;
+}
+
+/* abort currently processed job */
+static void imr_job_abort(void *priv)
+{
+	struct imr_ctx		*ctx = priv;
+	struct imr_device	*imr = ctx->imr;
+	unsigned long		flags;
+
+	/* protect access to internal device state */
+	spin_lock_irqsave(&imr->lock, flags);
+
+	/*
+	 * make sure current job is still current
+	 * (may get finished by interrupt already)
+	 */
+	if (v4l2_m2m_get_curr_priv(imr->m2m_dev) == ctx) {
+		v4l2_dbg(1, debug, &imr->v4l2_dev,
+			 "abort job: status=%x, DLSAR=0x%08x, DLPR=0x%08x\n",
+			 ioread32(imr->mmio + IMR_SR),
+			 ioread32(imr->mmio + IMR_DLSAR),
+			 ioread32(imr->mmio + IMR_DLPR));
+
+		/*
+		 * resetting the module while operation is active may lead to
+		 * h/w stall
+		 */
+		spin_unlock_irqrestore(&imr->lock, flags);
+	} else {
+		spin_unlock_irqrestore(&imr->lock, flags);
+		v4l2_dbg(1, debug, &imr->v4l2_dev,
+			 "job has completed already\n");
+	}
+}
+
+/* M2M interface definition */
+static struct v4l2_m2m_ops imr_m2m_ops = {
+	.device_run	= imr_device_run,
+	.job_ready	= imr_job_ready,
+	.job_abort	= imr_job_abort,
+};
+
+/*******************************************************************************
+ * Interrupt handling
+ ******************************************************************************/
+
+static irqreturn_t imr_irq_handler(int irq, void *data)
+{
+	struct imr_device	*imr = data;
+	struct vb2_v4l2_buffer	*src_buf, *dst_buf;
+	bool			finish = false;
+	u32			status;
+	struct imr_ctx		*ctx;
+
+	/* check and ack interrupt status */
+	status = ioread32(imr->mmio + IMR_SR);
+	iowrite32(status, imr->mmio + IMR_SRCR);
+	if (!(status & (IMR_SR_INT | IMR_SR_IER | IMR_SR_TRA))) {
+		v4l2_err(&imr->v4l2_dev, "spurious interrupt: %x\n", status);
+		return IRQ_NONE;
+	}
+
+	/* protect access to current context */
+	spin_lock(&imr->lock);
+
+	/* get current job context (may have been cancelled already) */
+	ctx = v4l2_m2m_get_curr_priv(imr->m2m_dev);
+	if (!ctx) {
+		v4l2_dbg(3, debug, &imr->v4l2_dev, "no active job\n");
+		goto handled;
+	}
+
+	/* remove buffers (may have been removed already?) */
+	src_buf = v4l2_m2m_src_buf_remove(ctx->m2m_ctx);
+	dst_buf = v4l2_m2m_dst_buf_remove(ctx->m2m_ctx);
+	if (!src_buf || !dst_buf) {
+		v4l2_dbg(3, debug, &imr->v4l2_dev,
+			 "no buffers associated with current context\n");
+		goto handled;
+	}
+
+	finish = true;
+
+	/* check for a TRAP interrupt indicating completion of current DL */
+	if (status & IMR_SR_TRA) {
+		/* operation completed normally; timestamp output buffer */
+		dst_buf->vb2_buf.timestamp = ktime_get_ns();
+		if (src_buf->flags & V4L2_BUF_FLAG_TIMECODE)
+			dst_buf->timecode = src_buf->timecode;
+		dst_buf->flags = src_buf->flags &
+			(V4L2_BUF_FLAG_TIMECODE | V4L2_BUF_FLAG_KEYFRAME |
+			 V4L2_BUF_FLAG_PFRAME | V4L2_BUF_FLAG_BFRAME |
+			 V4L2_BUF_FLAG_TSTAMP_SRC_MASK);
+		dst_buf->sequence = src_buf->sequence = ctx->sequence++;
+		v4l2_m2m_buf_done(src_buf, VB2_BUF_STATE_DONE);
+		v4l2_m2m_buf_done(dst_buf, VB2_BUF_STATE_DONE);
+
+		v4l2_dbg(3, debug, &imr->v4l2_dev,
+			 "buffers <0x%08x,0x%08x> done\n",
+			(u32)vb2_dma_contig_plane_dma_addr
+				(&src_buf->vb2_buf, 0),
+			(u32)vb2_dma_contig_plane_dma_addr
+				(&dst_buf->vb2_buf, 0));
+	} else {
+		/*
+		 * operation completed in error; no way to understand
+		 * what exactly went wrong
+		 */
+		v4l2_m2m_buf_done(src_buf, VB2_BUF_STATE_ERROR);
+		v4l2_m2m_buf_done(dst_buf, VB2_BUF_STATE_ERROR);
+
+		v4l2_dbg(3, debug, &imr->v4l2_dev,
+			 "buffers <0x%08x,0x%08x> done in error\n",
+			 (u32)vb2_dma_contig_plane_dma_addr
+				(&src_buf->vb2_buf, 0),
+			 (u32)vb2_dma_contig_plane_dma_addr
+				(&dst_buf->vb2_buf, 0));
+	}
+
+handled:
+	spin_unlock(&imr->lock);
+
+	/* finish current job (and start any pending) */
+	if (finish)
+		v4l2_m2m_job_finish(imr->m2m_dev, ctx->m2m_ctx);
+
+	return IRQ_HANDLED;
+}
+
+/*******************************************************************************
+ * Device probing/removal interface
+ ******************************************************************************/
+
+static int imr_probe(struct platform_device *pdev)
+{
+	struct imr_device	*imr;
+	struct resource		*res;
+	int			ret;
+
+	imr = devm_kzalloc(&pdev->dev, sizeof(*imr), GFP_KERNEL);
+	if (!imr)
+		return -ENOMEM;
+
+	mutex_init(&imr->mutex);
+	spin_lock_init(&imr->lock);
+	imr->dev = &pdev->dev;
+
+	/* memory-mapped registers */
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	imr->mmio = devm_ioremap_resource(&pdev->dev, res);
+	if (IS_ERR(imr->mmio))
+		return PTR_ERR(imr->mmio);
+
+	/* interrupt service routine registration */
+	imr->irq = ret = platform_get_irq(pdev, 0);
+	if (ret < 0) {
+		dev_err(&pdev->dev, "cannot find IRQ\n");
+		return ret;
+	}
+
+	ret = devm_request_irq(&pdev->dev, imr->irq, imr_irq_handler, 0,
+			       dev_name(&pdev->dev), imr);
+	if (ret) {
+		dev_err(&pdev->dev, "cannot claim IRQ %d\n", imr->irq);
+		return ret;
+	}
+
+	imr->clock = devm_clk_get(&pdev->dev, NULL);
+	if (IS_ERR(imr->clock)) {
+		dev_err(&pdev->dev, "cannot get clock\n");
+		return PTR_ERR(imr->clock);
+	}
+
+	/* create v4l2 device */
+	ret = v4l2_device_register(&pdev->dev, &imr->v4l2_dev);
+	if (ret) {
+		dev_err(&pdev->dev, "Failed to register v4l2 device\n");
+		return ret;
+	}
+
+	/* create mem2mem device handle */
+	imr->m2m_dev = v4l2_m2m_init(&imr_m2m_ops);
+	if (IS_ERR(imr->m2m_dev)) {
+		v4l2_err(&imr->v4l2_dev, "Failed to init mem2mem device\n");
+		ret = PTR_ERR(imr->m2m_dev);
+		goto device_register_rollback;
+	}
+
+	strlcpy(imr->video_dev.name, dev_name(&pdev->dev),
+		sizeof(imr->video_dev.name));
+	imr->video_dev.fops	    = &imr_fops;
+	imr->video_dev.device_caps  = V4L2_CAP_VIDEO_CAPTURE |
+				      V4L2_CAP_VIDEO_OUTPUT |
+				      V4L2_CAP_VIDEO_M2M | V4L2_CAP_STREAMING;
+	imr->video_dev.ioctl_ops    = &imr_ioctl_ops;
+	imr->video_dev.minor	    = -1;
+	imr->video_dev.release	    = video_device_release_empty;
+	imr->video_dev.lock	    = &imr->mutex;
+	imr->video_dev.v4l2_dev	    = &imr->v4l2_dev;
+	imr->video_dev.vfl_dir	    = VFL_DIR_M2M;
+
+	ret = video_register_device(&imr->video_dev, VFL_TYPE_GRABBER, -1);
+	if (ret) {
+		v4l2_err(&imr->v4l2_dev, "Failed to register video device\n");
+		goto m2m_init_rollback;
+	}
+
+	video_set_drvdata(&imr->video_dev, imr);
+	platform_set_drvdata(pdev, imr);
+
+	v4l2_info(&imr->v4l2_dev,
+		  "IMR device (pdev: %d) registered as /dev/video%d\n",
+		  pdev->id, imr->video_dev.num);
+
+	return 0;
+
+m2m_init_rollback:
+	v4l2_m2m_release(imr->m2m_dev);
+
+device_register_rollback:
+	v4l2_device_unregister(&imr->v4l2_dev);
+
+	return ret;
+}
+
+static int imr_remove(struct platform_device *pdev)
+{
+	struct imr_device *imr = platform_get_drvdata(pdev);
+
+	video_unregister_device(&imr->video_dev);
+	v4l2_m2m_release(imr->m2m_dev);
+	v4l2_device_unregister(&imr->v4l2_dev);
+
+	return 0;
+}
+
+/*******************************************************************************
+ * Power management
+ ******************************************************************************/
+
+#ifdef CONFIG_PM_SLEEP
+
+/* device suspend hook; clock control only - TBD */
+static int imr_pm_suspend(struct device *dev)
+{
+	struct imr_device *imr = dev_get_drvdata(dev);
+
+	WARN_ON(mutex_is_locked(&imr->mutex));
+
+	if (imr->refcount == 0)
+		return 0;
+
+	clk_disable_unprepare(imr->clock);
+
+	return 0;
+}
+
+/* device resume hook; clock control only */
+static int imr_pm_resume(struct device *dev)
+{
+	struct imr_device *imr = dev_get_drvdata(dev);
+
+	WARN_ON(mutex_is_locked(&imr->mutex));
+
+	if (imr->refcount == 0)
+		return 0;
+
+	clk_prepare_enable(imr->clock);
+
+	return 0;
+}
+
+#endif  /* CONFIG_PM_SLEEP */
+
+/* power management callbacks */
+static const struct dev_pm_ops imr_pm_ops = {
+	SET_SYSTEM_SLEEP_PM_OPS(imr_pm_suspend, imr_pm_resume)
+};
+
+/* device table */
+static const struct of_device_id imr_of_match[] = {
+	{ .compatible = "renesas,imr-lx4" },
+	{ },
+};
+
+/* platform driver interface */
+static struct platform_driver imr_platform_driver = {
+	.probe		= imr_probe,
+	.remove		= imr_remove,
+	.driver		= {
+		.owner		= THIS_MODULE,
+		.name		= "imr",
+		.pm		= &imr_pm_ops,
+		.of_match_table = imr_of_match,
+	},
+};
+
+module_platform_driver(imr_platform_driver);
+
+MODULE_ALIAS("imr");
+MODULE_AUTHOR("Cogent Embedded Inc. <sources@cogentembedded.com>");
+MODULE_DESCRIPTION("Renesas IMR-LX4 Driver");
+MODULE_LICENSE("GPL");
Index: media_tree/include/uapi/linux/rcar_imr.h
===================================================================
--- /dev/null
+++ media_tree/include/uapi/linux/rcar_imr.h
@@ -0,0 +1,94 @@ 
+/*
+ * rcar_imr.h -- R-Car IMR-LX4 Driver UAPI
+ *
+ * Copyright (C) 2016-2017 Cogent Embedded, Inc. <source@cogentembedded.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ */
+
+#ifndef __RCAR_IMR_H
+#define __RCAR_IMR_H
+
+#include <linux/videodev2.h>
+
+/*******************************************************************************
+ * Mapping specification descriptor
+ ******************************************************************************/
+
+struct imr_map_desc {
+	/* mapping types */
+	__u32			type;
+
+	/* total size of the mesh structure */
+	__u32			size;
+
+	/* map-specific user-pointer */
+	__u64			data;
+} __packed;
+
+/* regular mesh specification */
+#define IMR_MAP_MESH		(1 << 0)
+
+/* auto-generated source coordinates */
+#define IMR_MAP_AUTOSG		(1 << 1)
+
+/* auto-generated destination coordinates */
+#define IMR_MAP_AUTODG		(1 << 2)
+
+/* luminance correction flag */
+#define IMR_MAP_LUCE		(1 << 3)
+
+/* chromacity correction flag */
+#define IMR_MAP_CLCE		(1 << 4)
+
+/* vertex clockwise-mode order */
+#define IMR_MAP_TCM		(1 << 5)
+
+/* source coordinate decimal point position */
+#define __IMR_MAP_UVDPOR_SHIFT	8
+#define __IMR_MAP_UVDPOR(v)	(((v) >> __IMR_MAP_UVDPOR_SHIFT) & 0x7)
+#define IMR_MAP_UVDPOR(n)	(((n) & 0x7) << __IMR_MAP_UVDPOR_SHIFT)
+
+/* destination coordinate sub-pixel mode */
+#define IMR_MAP_DDP		(1 << 11)
+
+/* luminance correction offset decimal point position */
+#define __IMR_MAP_YLDPO_SHIFT	12
+#define __IMR_MAP_YLDPO(v)	(((v) >> __IMR_MAP_YLDPO_SHIFT) & 0x7)
+#define IMR_MAP_YLDPO(n)	(((n) & 0x7) << __IMR_MAP_YLDPO_SHIFT)
+
+/* chromacity (U) correction offset decimal point position */
+#define __IMR_MAP_UBDPO_SHIFT	15
+#define __IMR_MAP_UBDPO(v)	(((v) >> __IMR_MAP_UBDPO_SHIFT) & 0x7)
+#define IMR_MAP_UBDPO(n)	(((n) & 0x7) << __IMR_MAP_UBDPO_SHIFT)
+
+/* chromacity (V) correction offset decimal point position */
+#define __IMR_MAP_VRDPO_SHIFT	18
+#define __IMR_MAP_VRDPO(v)	(((v) >> __IMR_MAP_VRDPO_SHIFT) & 0x7)
+#define IMR_MAP_VRDPO(n)	(((n) & 0x7) << __IMR_MAP_VRDPO_SHIFT)
+
+/* regular mesh specification */
+struct imr_mesh {
+	/* rectangular mesh size */
+	__u16			rows, columns;
+
+	/* mesh parameters */
+	__u16			x0, y0, dx, dy;
+} __packed;
+
+/* vertex-buffer-object (VBO) descriptor */
+struct imr_vbo {
+	/* number of triangles */
+	__u16			num;
+} __packed;
+
+/*******************************************************************************
+ * Private IOCTL codes
+ ******************************************************************************/
+
+#define VIDIOC_IMR_MESH _IOW('V', BASE_VIDIOC_PRIVATE + 0, struct imr_map_desc)
+
+#endif /* __RCAR_IMR_H */