diff mbox

[v2,1/3] dmaengine: mpc512x: add device tree binding document

Message ID 1403088492-15241-2-git-send-email-a13xp0p0v88@gmail.com (mailing list archive)
State Superseded
Delegated to: Vinod Koul
Headers show

Commit Message

Alexander Popov June 18, 2014, 10:48 a.m. UTC
Introduce a device tree binding document for the MPC512x DMA controller

Signed-off-by: Alexander Popov <a13xp0p0v88@gmail.com>
---
 .../devicetree/bindings/dma/mpc512x-dma.txt        | 31 ++++++++++++++++++++++
 1 file changed, 31 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/dma/mpc512x-dma.txt

Comments

Mark Rutland June 18, 2014, 1:37 p.m. UTC | #1
On Wed, Jun 18, 2014 at 11:48:10AM +0100, Alexander Popov wrote:
> Introduce a device tree binding document for the MPC512x DMA controller
> 
> Signed-off-by: Alexander Popov <a13xp0p0v88@gmail.com>
> ---
>  .../devicetree/bindings/dma/mpc512x-dma.txt        | 31 ++++++++++++++++++++++
>  1 file changed, 31 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/dma/mpc512x-dma.txt
> 
> diff --git a/Documentation/devicetree/bindings/dma/mpc512x-dma.txt b/Documentation/devicetree/bindings/dma/mpc512x-dma.txt
> new file mode 100644
> index 0000000..95e2ca0
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/dma/mpc512x-dma.txt
> @@ -0,0 +1,31 @@
> +* Freescale MPC512x and MPC8308 DMA Controller
> +
> +The DMA controller in Freescale MPC512x and MPC8308 SoCs can move
> +blocks of memory contents between memory and peripherals or
> +from memory to memory.
> +
> +Refer to "Generic DMA Controller and DMA request bindings" in
> +the dma/dma.txt file for a more detailed description of binding.
> +
> +Required properties:
> +- compatible: should be "fsl,mpc5121-dma" or "fsl,mpc8308-dma";
> +- reg: should contain the DMA controller registers location and length;
> +- interrupt for the DMA controller: syntax of interrupt client node
> +	is described in interrupt-controller/interrupts.txt file.
> +
> +Optional properties:
> +- #dma-cells: the length of the DMA specifier, must be <1>.
> +	Each channel of this DMA controller has a peripheral request line,
> +	the assignment is fixed in hardware. This one cell
> +	in dmas property of a client device represents the channel number.

Surely this is required to be able to refer to DMA channels on the
device?

Mark.
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Alexander Popov June 18, 2014, 2:56 p.m. UTC | #2
Hello Mark, thanks for your reply!

2014-06-18 17:37 GMT+04:00 Mark Rutland <mark.rutland@arm.com>:
> On Wed, Jun 18, 2014 at 11:48:10AM +0100, Alexander Popov wrote:
>> Introduce a device tree binding document for the MPC512x DMA controller
>>
>> Signed-off-by: Alexander Popov <a13xp0p0v88@gmail.com>
>> ---
>>  .../devicetree/bindings/dma/mpc512x-dma.txt        | 31 ++++++++++++++++++++++
>>  1 file changed, 31 insertions(+)
>>  create mode 100644 Documentation/devicetree/bindings/dma/mpc512x-dma.txt
>>
>> diff --git a/Documentation/devicetree/bindings/dma/mpc512x-dma.txt b/Documentation/devicetree/bindings/dma/mpc512x-dma.txt
>> new file mode 100644
>> index 0000000..95e2ca0
>> --- /dev/null
>> +++ b/Documentation/devicetree/bindings/dma/mpc512x-dma.txt
>> @@ -0,0 +1,31 @@
>> +* Freescale MPC512x and MPC8308 DMA Controller
>> +
>> +The DMA controller in Freescale MPC512x and MPC8308 SoCs can move
>> +blocks of memory contents between memory and peripherals or
>> +from memory to memory.
>> +
>> +Refer to "Generic DMA Controller and DMA request bindings" in
>> +the dma/dma.txt file for a more detailed description of binding.
>> +
>> +Required properties:
>> +- compatible: should be "fsl,mpc5121-dma" or "fsl,mpc8308-dma";
>> +- reg: should contain the DMA controller registers location and length;
>> +- interrupt for the DMA controller: syntax of interrupt client node
>> +     is described in interrupt-controller/interrupts.txt file.
>> +
>> +Optional properties:
>> +- #dma-cells: the length of the DMA specifier, must be <1>.
>> +     Each channel of this DMA controller has a peripheral request line,
>> +     the assignment is fixed in hardware. This one cell
>> +     in dmas property of a client device represents the channel number.
>
> Surely this is required to be able to refer to DMA channels on the
> device?

Excuse me, I didn't understand your question.
Do you inquire about the reason of making #dma-cells an optional property?
It's optional because device tree based lookup support is made
optional (part 3/3).

Best regards,
Alexander
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Alexander Popov June 19, 2014, 1:59 p.m. UTC | #3
2014-06-18 18:56 GMT+04:00 Alexander Popov <a13xp0p0v88@gmail.com>:
> 2014-06-18 17:37 GMT+04:00 Mark Rutland <mark.rutland@arm.com>:
>> On Wed, Jun 18, 2014 at 11:48:10AM +0100, Alexander Popov wrote:
>>> Introduce a device tree binding document for the MPC512x DMA controller
>>> +Optional properties:
>>> +- #dma-cells: the length of the DMA specifier, must be <1>.
>>> +     Each channel of this DMA controller has a peripheral request line,
>>> +     the assignment is fixed in hardware. This one cell
>>> +     in dmas property of a client device represents the channel number.
>>
>> Surely this is required to be able to refer to DMA channels on the
>> device?
>
> Excuse me, I didn't understand your question.
> Do you inquire about the reason of making #dma-cells an optional property?
> It's optional because device tree based lookup support is made
> optional (part 3/3).

Mark, did I answer your question?
Should I fix anything in this patch series?

Hope for the reply.
Alexander
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Mark Rutland July 4, 2014, 5:04 p.m. UTC | #4
Hi Alexander,

Apologies for the late reply. DT-related email is somewhat a firehose
and unfortunately I lose track of things.

On Thu, Jun 19, 2014 at 02:59:19PM +0100, Alexander Popov wrote:
> 2014-06-18 18:56 GMT+04:00 Alexander Popov <a13xp0p0v88@gmail.com>:
> > 2014-06-18 17:37 GMT+04:00 Mark Rutland <mark.rutland@arm.com>:
> >> On Wed, Jun 18, 2014 at 11:48:10AM +0100, Alexander Popov wrote:
> >>> Introduce a device tree binding document for the MPC512x DMA controller
> >>> +Optional properties:
> >>> +- #dma-cells: the length of the DMA specifier, must be <1>.
> >>> +     Each channel of this DMA controller has a peripheral request line,
> >>> +     the assignment is fixed in hardware. This one cell
> >>> +     in dmas property of a client device represents the channel number.
> >>
> >> Surely this is required to be able to refer to DMA channels on the
> >> device?
> >
> > Excuse me, I didn't understand your question.
> > Do you inquire about the reason of making #dma-cells an optional property?
> > It's optional because device tree based lookup support is made
> > optional (part 3/3).
> 
> Mark, did I answer your question?
> Should I fix anything in this patch series?

I would move it under required properties even if we happen to not use
it in certain edge cases.

Moving forwards everything should be DT-driven, so it'll be necessary.

Thanks,
Mark.
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diff mbox

Patch

diff --git a/Documentation/devicetree/bindings/dma/mpc512x-dma.txt b/Documentation/devicetree/bindings/dma/mpc512x-dma.txt
new file mode 100644
index 0000000..95e2ca0
--- /dev/null
+++ b/Documentation/devicetree/bindings/dma/mpc512x-dma.txt
@@ -0,0 +1,31 @@ 
+* Freescale MPC512x and MPC8308 DMA Controller
+
+The DMA controller in Freescale MPC512x and MPC8308 SoCs can move
+blocks of memory contents between memory and peripherals or
+from memory to memory.
+
+Refer to "Generic DMA Controller and DMA request bindings" in
+the dma/dma.txt file for a more detailed description of binding.
+
+Required properties:
+- compatible: should be "fsl,mpc5121-dma" or "fsl,mpc8308-dma";
+- reg: should contain the DMA controller registers location and length;
+- interrupt for the DMA controller: syntax of interrupt client node
+	is described in interrupt-controller/interrupts.txt file.
+
+Optional properties:
+- #dma-cells: the length of the DMA specifier, must be <1>.
+	Each channel of this DMA controller has a peripheral request line,
+	the assignment is fixed in hardware. This one cell
+	in dmas property of a client device represents the channel number.
+
+Example:
+
+	dma0: dma@14000 {
+		compatible = "fsl,mpc5121-dma";
+		reg = <0x14000 0x1800>;
+		interrupts = <65 0x8>;
+		#dma-cells = <1>;
+	};
+
+DMA clients must use the format described in dma/dma.txt file.