diff mbox series

[v4,3/6] drm: Add driver for Solomon SSD130x OLED displays

Message ID 20220211091927.2988283-4-javierm@redhat.com (mailing list archive)
State Not Applicable
Headers show
Series drm: Add driver for Solomon SSD130x OLED displays | expand

Commit Message

Javier Martinez Canillas Feb. 11, 2022, 9:19 a.m. UTC
This adds a DRM driver for SSD1305, SSD1306, SSD1307 and SSD1309 Solomon
OLED display controllers.

It's only the core part of the driver and a bus specific driver is needed
for each transport interface supported by the display controllers.

Signed-off-by: Javier Martinez Canillas <javierm@redhat.com>
---

Changes in v4:
- Rename vbat supply to vcc since is how's labeled in the device (Mark Brown)
- Don't make the regulator option since is always needed (Mark Brown)
- Add solomon Kconfig source and directory inclusion sorted (Andy Shevchenko)
- Use SSD130x instead of SSD130X to denote is not a model name (Andy Shevchenko)
- Check if there's a reset pin in the callee and not the caller (Andy Shevchenko)
- Define missing commands instead of using magic numbers (Andy Shevchenko)
- Use GENMASK() and FIELD_PREP() macros when possible (Andy Shevchenko)
- Avoid using ternary operators to ease code readablity (Andy Shevchenko)
- Use i++ instead of --i on some for loops (Andy Shevchenko)
- Remove redundant blank lines (Andy Shevchenko)
- Rename power_off label to out_power_off (Andy Shevchenko)
- Use dev_err_probe() even if no -EPROBE_DEFER (Andy Shevchenko)
- Don't use plural Authors if there's only one (Andy Shevchenko)

Changes in v3:
- Move driver from tiny sub-dir to drivers/gpu/drm/solomon (Sam Ravnborg)
- Split driver in a bus agnostic core and bus specific (Andy Shevchenko)
- Use regmap to access the chip registers (Andy Shevchenko)
- Remove unnecessary blank lines (Andy Shevchenko)
- Remove unneeded inline specifier in functions (Andy Shevchenko)
- Add a comment about always returning a single mode (Andy Shevchenko)
- Change write command logic to use do while loop (Andy Shevchenko)
- Use "firmware description" instead of "device tree" (Andy Shevchenko)
- Use return foo() instead of returning the return value (Andy Shevchenko)
- Don't split lines longer than 80 chars if makes less readable (Andy Shevchenko)
- Remove redundant else statements in .mode_valid callback (Andy Shevchenko)
- Rename powero{n,ff}() functions to power_o{n,ff)() (Andy Shevchenko)
- Use dev_err_probe() to prevent spam logs on probe deferral (Andy Shevchenko)
- Remove ',' after sentinel terminator in array (Andy Shevchenko)
- Fix a bug when doing partial updates (Geert Uytterhoeven)

Changes in v2:
- Drop patch that was adding a DRM_MODE_CONNECTOR_I2C type.
- Invert order of backlight {en,dis}able and display {on,off} (Sam Ravnborg)
- Don't clear the screen and turn on display on probe (Sam Ravnborg)
- Use backlight_get_brightness() macro to get BL brightness (Sam Ravnborg)
- Use dev managed version of devm_backlight_device_register() (Sam Ravnborg)
- Use dev_name(dev) for backlight name instead of an array (Sam Ravnborg)
- Drop the .get_brightness callback since isn't needed  (Sam Ravnborg)
- Rename driver to ssd130x since supports a display family (Thomas Zimmermann)
- Drop the TINY prefix from the Kconfig symbol (Thomas Zimmermann)
- Sort the Kconfig symbol dependencies alphabetically (Thomas Zimmermann)
- Rename struct ssd130x_array to struct ssd130x_i2c_msg (Thomas Zimmermann)
- Rename struct ssd130x_i2c_msg .type member to .cmd (Thomas Zimmermann)
- Use sizeof(*foo) instead of sizeof(struct foo) (Thomas Zimmermann)
- Use struct_size() macro to calculate sizeof(*foo) + len (Thomas Zimmermann)
- Use kcalloc() instead of kmalloc_array() + memset() (Thomas Zimmermann)
- Use shadow plane helpers virtual screen support (Thomas Zimmermann)
- Remove unused goto label in ssd1307_fb_blit_rect() (Thomas Zimmermann)
- Use drm_set_preferred_mode() inset of manually set (Thomas Zimmermann)
- Use shadow plane helpers virtual screen support (Thomas Zimmermann)
- Remove unused goto label in ssd1307_fb_blit_rect() (Thomas Zimmermann)
- Use drm_set_preferred_mode() inset of manually set (Thomas Zimmermann)
- Reorganize code in probe to make it more legible (Thomas Zimmermann)
- ssd130x_write_cmd() uses varargs to simplify I2C code (Thomas Zimmermann)
- Move regulator/pwm init logic to display pipe enable callback.

 drivers/gpu/drm/Kconfig           |   2 +
 drivers/gpu/drm/Makefile          |   1 +
 drivers/gpu/drm/solomon/Kconfig   |  12 +
 drivers/gpu/drm/solomon/Makefile  |   1 +
 drivers/gpu/drm/solomon/ssd130x.c | 852 ++++++++++++++++++++++++++++++
 drivers/gpu/drm/solomon/ssd130x.h |  76 +++
 6 files changed, 944 insertions(+)
 create mode 100644 drivers/gpu/drm/solomon/Kconfig
 create mode 100644 drivers/gpu/drm/solomon/Makefile
 create mode 100644 drivers/gpu/drm/solomon/ssd130x.c
 create mode 100644 drivers/gpu/drm/solomon/ssd130x.h

Comments

Andy Shevchenko Feb. 11, 2022, 11:33 a.m. UTC | #1
On Fri, Feb 11, 2022 at 10:19:24AM +0100, Javier Martinez Canillas wrote:
> This adds a DRM driver for SSD1305, SSD1306, SSD1307 and SSD1309 Solomon
> OLED display controllers.
> 
> It's only the core part of the driver and a bus specific driver is needed
> for each transport interface supported by the display controllers.

...

> +#include <linux/backlight.h>
> +#include <linux/bitfield.h>

bits.h
(FYI, specifically sent a patch few days ago to add explicitly the inclusions
 that needed for bitfield operations in the example inside bitfield.h).

> +#include <linux/delay.h>
> +#include <linux/gpio/consumer.h>
> +#include <linux/property.h>
> +#include <linux/pwm.h>
> +#include <linux/regulator/consumer.h>

...

> +#define SSD130X_SET_ADDRESS_MODE_HORIZONTAL	(0x00)
> +#define SSD130X_SET_ADDRESS_MODE_VERTICAL	(0x01)
> +#define SSD130X_SET_ADDRESS_MODE_PAGE		(0x02)
> +
> +#define SSD130X_SET_AREA_COLOR_MODE_ENABLE	(0x1e)
> +#define SSD130X_SET_AREA_COLOR_MODE_LOW_POWER	(0x05)

Do the parentheses add anything here?

...

> +/*
> + * Helper to write command (SSD130X_COMMAND). The fist variadic argument
> + * is the command to write and the following are the command options.

This is not correct explanation. Please, rephrase to show that _each_ of the
options is sent with a preceding command.

> + */
> +static int ssd130x_write_cmd(struct ssd130x_device *ssd130x, int count,
> +				    /* u8 cmd, u8 option, ... */...)
> +{
> +	va_list ap;
> +	u8 value;
> +	int ret;
> +
> +	va_start(ap, count);
> +
> +	do {
> +		value = va_arg(ap, int);
> +		ret = regmap_write(ssd130x->regmap, SSD130X_COMMAND, (u8)value);
> +		if (ret)
> +			goto out_end;
> +	} while (--count);
> +
> +out_end:
> +	va_end(ap);
> +
> +	return ret;
> +}

...

> +	if (ssd130x->device_info->need_pwm) {

Yeah, unfortunately we still don't have pwm_get_optional()...

> +		ret = ssd130x_pwm_enable(ssd130x);
> +		if (ret) {
> +			dev_err(dev, "Failed to enable PWM: %d\n", ret);
> +			regulator_disable(ssd130x->vcc_reg);
> +			return ret;
> +		}
> +	}

...

> +static void ssd130x_power_off(struct ssd130x_device *ssd130x)
> +{

> +	if (ssd130x->device_info->need_pwm) {

Redundant check. The two below are NULL-aware.

> +		pwm_disable(ssd130x->pwm);
> +		pwm_put(ssd130x->pwm);
> +	}
> +
> +	regulator_disable(ssd130x->vcc_reg);
> +}

...

> +	ret = ssd130x_write_cmd(ssd130x, 2, SSD130X_SET_COM_PINS_CONFIG, compins);
> +	if (ret < 0)
> +		return ret;

> +
> +

One blank line is enough.

...

> +	for (i = y / 8; i < y / 8 + pages; i++) {
> +		int m = 8;
> +
> +		/* Last page may be partial */
> +		if (8 * (i + 1) > ssd130x->height)
> +			m = ssd130x->height % 8;

Perhaps it can be moved out of the loop with refactored piece below.

> +		for (j = x; j < x + width; j++) {
> +			u8 data = 0;
> +
> +			for (k = 0; k < m; k++) {
> +				u8 byte = buf[(8 * i + k) * line_length + j / 8];
> +				u8 bit = (byte >> (j % 8)) & 1;
> +
> +				data |= bit << k;
> +			}
> +			data_array[array_idx++] = data;
> +		}
> +	}

...

> +	bl = devm_backlight_device_register(dev, dev_name(dev), dev, ssd130x,
> +					    &ssd130xfb_bl_ops, NULL);
> +	if (IS_ERR(bl)) {

> +		ret = PTR_ERR(bl);
> +		dev_err_probe(dev, ret, "Unable to register backlight device\n");
> +		return ERR_PTR(ret);

		dev_err_probe(dev, PTR_ERR(bl), "Unable to register backlight device\n");
		return bl;

?

> +	}
Javier Martinez Canillas Feb. 11, 2022, 12:05 p.m. UTC | #2
On 2/11/22 12:33, Andy Shevchenko wrote:
> On Fri, Feb 11, 2022 at 10:19:24AM +0100, Javier Martinez Canillas wrote:
>> This adds a DRM driver for SSD1305, SSD1306, SSD1307 and SSD1309 Solomon
>> OLED display controllers.
>>
>> It's only the core part of the driver and a bus specific driver is needed
>> for each transport interface supported by the display controllers.
> 
> ...
> 
>> +#include <linux/backlight.h>
>> +#include <linux/bitfield.h>
> 
> bits.h

Ok, missed that both weren't in the same macro.

> (FYI, specifically sent a patch few days ago to add explicitly the inclusions
>  that needed for bitfield operations in the example inside bitfield.h).
> 
>> +#include <linux/delay.h>
>> +#include <linux/gpio/consumer.h>
>> +#include <linux/property.h>
>> +#include <linux/pwm.h>
>> +#include <linux/regulator/consumer.h>
> 
> ...
> 
>> +#define SSD130X_SET_ADDRESS_MODE_HORIZONTAL	(0x00)
>> +#define SSD130X_SET_ADDRESS_MODE_VERTICAL	(0x01)
>> +#define SSD130X_SET_ADDRESS_MODE_PAGE		(0x02)
>> +
>> +#define SSD130X_SET_AREA_COLOR_MODE_ENABLE	(0x1e)
>> +#define SSD130X_SET_AREA_COLOR_MODE_LOW_POWER	(0x05)
> 
> Do the parentheses add anything here?
>

Not really, the fbdev driver used it and I understood that was
a convention to denote that these are command options and not a
command or register. I'll drop them.

> ...
> 
>> +/*
>> + * Helper to write command (SSD130X_COMMAND). The fist variadic argument
>> + * is the command to write and the following are the command options.
> 
> This is not correct explanation. Please, rephrase to show that _each_ of the
> options is sent with a preceding command.
>

It's a correct explanation IMO from the caller point of view. The first argument
is the command sent (i.e: SSD130X_SET_ADDRESS_MODE) and the next ones are the
the command options (i.e: SSD130X_SET_ADDRESS_MODE_HORIZONTAL).

The fact that each command and options are preceding with a SSD130X_COMMAND
value is part of the protocol of the device and a detail that's abstracted
away by this helper function to the callers.

>> + */
>> +static int ssd130x_write_cmd(struct ssd130x_device *ssd130x, int count,
>> +				    /* u8 cmd, u8 option, ... */...)
>> +{
>> +	va_list ap;
>> +	u8 value;
>> +	int ret;
>> +
>> +	va_start(ap, count);
>> +
>> +	do {
>> +		value = va_arg(ap, int);
>> +		ret = regmap_write(ssd130x->regmap, SSD130X_COMMAND, (u8)value);
>> +		if (ret)
>> +			goto out_end;
>> +	} while (--count);
>> +
>> +out_end:
>> +	va_end(ap);
>> +
>> +	return ret;
>> +}
> 
> ...
> 
>> +	if (ssd130x->device_info->need_pwm) {
> 
> Yeah, unfortunately we still don't have pwm_get_optional()...
> 
>> +		ret = ssd130x_pwm_enable(ssd130x);
>> +		if (ret) {
>> +			dev_err(dev, "Failed to enable PWM: %d\n", ret);
>> +			regulator_disable(ssd130x->vcc_reg);
>> +			return ret;
>> +		}
>> +	}
> 
> ...
> 
>> +static void ssd130x_power_off(struct ssd130x_device *ssd130x)
>> +{
> 
>> +	if (ssd130x->device_info->need_pwm) {
> 
> Redundant check. The two below are NULL-aware.
>

Ok, I'll drop it.

>> +		pwm_disable(ssd130x->pwm);
>> +		pwm_put(ssd130x->pwm);
>> +	}
>> +
>> +	regulator_disable(ssd130x->vcc_reg);
>> +}
> 
> ...
> 
>> +	ret = ssd130x_write_cmd(ssd130x, 2, SSD130X_SET_COM_PINS_CONFIG, compins);
>> +	if (ret < 0)
>> +		return ret;
> 
>> +
>> +
> 
> One blank line is enough.
>

Indeed, that was a left over when changing this to use the macros.
 
> ...
> 
>> +	for (i = y / 8; i < y / 8 + pages; i++) {
>> +		int m = 8;
>> +
>> +		/* Last page may be partial */
>> +		if (8 * (i + 1) > ssd130x->height)
>> +			m = ssd130x->height % 8;
> 
> Perhaps it can be moved out of the loop with refactored piece below.
>

Not sure I'm following since it depends on the for loop iterator value.

[snip]

>> +	bl = devm_backlight_device_register(dev, dev_name(dev), dev, ssd130x,
>> +					    &ssd130xfb_bl_ops, NULL);
>> +	if (IS_ERR(bl)) {
> 
>> +		ret = PTR_ERR(bl);
>> +		dev_err_probe(dev, ret, "Unable to register backlight device\n");
>> +		return ERR_PTR(ret);
> 
> 		dev_err_probe(dev, PTR_ERR(bl), "Unable to register backlight device\n");
> 		return bl;
> 
> ?

No, because this function's return value is a struct ssd130x_device pointer,
not a struct backlight_device pointer.

Best regards,
Geert Uytterhoeven Feb. 11, 2022, 12:23 p.m. UTC | #3
Hi Javier,

On Fri, Feb 11, 2022 at 1:06 PM Javier Martinez Canillas
<javierm@redhat.com> wrote:
> On 2/11/22 12:33, Andy Shevchenko wrote:
> > On Fri, Feb 11, 2022 at 10:19:24AM +0100, Javier Martinez Canillas wrote:
> >> This adds a DRM driver for SSD1305, SSD1306, SSD1307 and SSD1309 Solomon
> >> OLED display controllers.
> >>
> >> It's only the core part of the driver and a bus specific driver is needed
> >> for each transport interface supported by the display controllers.

> >> +    bl = devm_backlight_device_register(dev, dev_name(dev), dev, ssd130x,
> >> +                                        &ssd130xfb_bl_ops, NULL);
> >> +    if (IS_ERR(bl)) {
> >
> >> +            ret = PTR_ERR(bl);
> >> +            dev_err_probe(dev, ret, "Unable to register backlight device\n");
> >> +            return ERR_PTR(ret);
> >
> >               dev_err_probe(dev, PTR_ERR(bl), "Unable to register backlight device\n");
> >               return bl;
> >
> > ?
>
> No, because this function's return value is a struct ssd130x_device pointer,
> not a struct backlight_device pointer.

Hence

    return ERR_PTR(dev_err_probe(dev, PTR_ERR(bl),
                                 "Unable to register backlight device\n"));

?

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
Javier Martinez Canillas Feb. 11, 2022, 12:27 p.m. UTC | #4
Hello Geert,

On 2/11/22 13:23, Geert Uytterhoeven wrote:

[snip]

>>>> +    if (IS_ERR(bl)) {
>>>
>>>> +            ret = PTR_ERR(bl);
>>>> +            dev_err_probe(dev, ret, "Unable to register backlight device\n");
>>>> +            return ERR_PTR(ret);
>>>
>>>               dev_err_probe(dev, PTR_ERR(bl), "Unable to register backlight device\n");
>>>               return bl;
>>>
>>> ?
>>
>> No, because this function's return value is a struct ssd130x_device pointer,
>> not a struct backlight_device pointer.
> 
> Hence
> 
>     return ERR_PTR(dev_err_probe(dev, PTR_ERR(bl),
>                                  "Unable to register backlight device\n"));
> 
> ?
> 

Thanks, that would work.

Best regards,
Thomas Zimmermann Feb. 11, 2022, 12:44 p.m. UTC | #5
Hi

Am 11.02.22 um 10:19 schrieb Javier Martinez Canillas:
...
> +
> +static void ssd130x_display_pipe_enable(struct drm_simple_display_pipe *pipe,
> +					struct drm_crtc_state *crtc_state,
> +					struct drm_plane_state *plane_state)
> +{
> +	struct ssd130x_device *ssd130x = drm_to_ssd130x(pipe->crtc.dev);
> +	struct drm_device *drm = &ssd130x->drm;
> +	int idx, ret;
> +
> +	ret = ssd130x_power_on(ssd130x);
> +	if (ret)
> +		return;
> +
> +	ret = ssd130x_init(ssd130x);
> +	if (ret)
> +		goto out_power_off;
> +
> +	if (!drm_dev_enter(drm, &idx))
> +		goto out_power_off;
> +
> +	ssd130x_clear_screen(ssd130x);

Rather than clearing the screen, send the whole fb onto the display.

Best regards
Thomas

> +
> +	ssd130x_write_cmd(ssd130x, 1, SSD130X_DISPLAY_ON);
> +
> +	backlight_enable(ssd130x->bl_dev);
> +
> +	drm_dev_exit(idx);
> +
> +	return;
> +out_power_off:
> +	ssd130x_power_off(ssd130x);
> +}
> +
> +static void ssd130x_display_pipe_disable(struct drm_simple_display_pipe *pipe)
> +{
> +	struct ssd130x_device *ssd130x = drm_to_ssd130x(pipe->crtc.dev);
> +	struct drm_device *drm = &ssd130x->drm;
> +	int idx;
> +
> +	if (!drm_dev_enter(drm, &idx))
> +		return;
> +
> +	ssd130x_clear_screen(ssd130x);
> +
> +	backlight_disable(ssd130x->bl_dev);
> +
> +	ssd130x_write_cmd(ssd130x, 1, SSD130X_DISPLAY_OFF);
> +
> +	ssd130x_power_off(ssd130x);
> +
> +	drm_dev_exit(idx);
> +}
> +
> +static void ssd130x_display_pipe_update(struct drm_simple_display_pipe *pipe,
> +					struct drm_plane_state *old_plane_state)
> +{
> +	struct ssd130x_device *ssd130x = drm_to_ssd130x(pipe->crtc.dev);
> +	struct drm_plane_state *plane_state = pipe->plane.state;
> +	struct drm_shadow_plane_state *shadow_plane_state = to_drm_shadow_plane_state(plane_state);
> +	struct drm_framebuffer *fb = plane_state->fb;
> +	struct drm_device *drm = &ssd130x->drm;
> +	struct drm_rect src_clip, dst_clip;
> +	int idx;
> +
> +	if (!fb)
> +		return;
> +
> +	if (!pipe->crtc.state->active)
> +		return;
> +
> +	if (!drm_atomic_helper_damage_merged(old_plane_state, plane_state, &src_clip))
> +		return;
> +
> +	dst_clip = plane_state->dst;
> +	if (!drm_rect_intersect(&dst_clip, &src_clip))
> +		return;
> +
> +	if (!drm_dev_enter(drm, &idx))
> +		return;
> +
> +	ssd130x_fb_blit_rect(plane_state->fb, &shadow_plane_state->data[0], &dst_clip);
> +
> +	drm_dev_exit(idx);
> +}
> +
> +static const struct drm_simple_display_pipe_funcs ssd130x_pipe_funcs = {
> +	.mode_valid = ssd130x_display_pipe_mode_valid,
> +	.enable = ssd130x_display_pipe_enable,
> +	.disable = ssd130x_display_pipe_disable,
> +	.update = ssd130x_display_pipe_update,
> +	DRM_GEM_SIMPLE_DISPLAY_PIPE_SHADOW_PLANE_FUNCS,
> +};
> +
> +static int ssd130x_connector_get_modes(struct drm_connector *connector)
> +{
> +	struct ssd130x_device *ssd130x = drm_to_ssd130x(connector->dev);
> +	struct drm_display_mode *mode = &ssd130x->mode;
> +	struct device *dev = ssd130x->dev;
> +
> +	mode = drm_mode_duplicate(connector->dev, &ssd130x->mode);
> +	if (!mode) {
> +		dev_err(dev, "Failed to duplicated mode\n");
> +		return 0;
> +	}
> +
> +	drm_mode_probed_add(connector, mode);
> +	drm_set_preferred_mode(connector, mode->hdisplay, mode->vdisplay);
> +
> +	/* There is only a single mode */
> +	return 1;
> +}
> +
> +static const struct drm_connector_helper_funcs ssd130x_connector_helper_funcs = {
> +	.get_modes = ssd130x_connector_get_modes,
> +};
> +
> +static const struct drm_connector_funcs ssd130x_connector_funcs = {
> +	.reset = drm_atomic_helper_connector_reset,
> +	.fill_modes = drm_helper_probe_single_connector_modes,
> +	.destroy = drm_connector_cleanup,
> +	.atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state,
> +	.atomic_destroy_state = drm_atomic_helper_connector_destroy_state,
> +};
> +
> +static const struct drm_mode_config_funcs ssd130x_mode_config_funcs = {
> +	.fb_create = drm_gem_fb_create_with_dirty,
> +	.atomic_check = drm_atomic_helper_check,
> +	.atomic_commit = drm_atomic_helper_commit,
> +};
> +
> +static const uint32_t ssd130x_formats[] = {
> +	DRM_FORMAT_XRGB8888,
> +};
> +
> +DEFINE_DRM_GEM_FOPS(ssd130x_fops);
> +
> +static const struct drm_driver ssd130x_drm_driver = {
> +	DRM_GEM_SHMEM_DRIVER_OPS,
> +	.name			= DRIVER_NAME,
> +	.desc			= DRIVER_DESC,
> +	.date			= DRIVER_DATE,
> +	.major			= DRIVER_MAJOR,
> +	.minor			= DRIVER_MINOR,
> +	.driver_features	= DRIVER_ATOMIC | DRIVER_GEM | DRIVER_MODESET,
> +	.fops			= &ssd130x_fops,
> +};
> +
> +static int ssd130x_update_bl(struct backlight_device *bdev)
> +{
> +	struct ssd130x_device *ssd130x = bl_get_data(bdev);
> +	int brightness = backlight_get_brightness(bdev);
> +	int ret;
> +
> +	ssd130x->contrast = brightness;
> +
> +	ret = ssd130x_write_cmd(ssd130x, 1, SSD130X_CONTRAST);
> +	if (ret < 0)
> +		return ret;
> +
> +	ret = ssd130x_write_cmd(ssd130x, 1, ssd130x->contrast);
> +	if (ret < 0)
> +		return ret;
> +
> +	return 0;
> +}
> +
> +static const struct backlight_ops ssd130xfb_bl_ops = {
> +	.update_status	= ssd130x_update_bl,
> +};
> +
> +static void ssd130x_parse_properties(struct ssd130x_device *ssd130x)
> +{
> +	struct device *dev = ssd130x->dev;
> +
> +	if (device_property_read_u32(dev, "solomon,width", &ssd130x->width))
> +		ssd130x->width = 96;
> +
> +	if (device_property_read_u32(dev, "solomon,height", &ssd130x->height))
> +		ssd130x->height = 16;
> +
> +	if (device_property_read_u32(dev, "solomon,page-offset", &ssd130x->page_offset))
> +		ssd130x->page_offset = 1;
> +
> +	if (device_property_read_u32(dev, "solomon,col-offset", &ssd130x->col_offset))
> +		ssd130x->col_offset = 0;
> +
> +	if (device_property_read_u32(dev, "solomon,com-offset", &ssd130x->com_offset))
> +		ssd130x->com_offset = 0;
> +
> +	if (device_property_read_u32(dev, "solomon,prechargep1", &ssd130x->prechargep1))
> +		ssd130x->prechargep1 = 2;
> +
> +	if (device_property_read_u32(dev, "solomon,prechargep2", &ssd130x->prechargep2))
> +		ssd130x->prechargep2 = 2;
> +
> +	if (!device_property_read_u8_array(dev, "solomon,lookup-table",
> +					   ssd130x->lookup_table,
> +					   ARRAY_SIZE(ssd130x->lookup_table)))
> +		ssd130x->lookup_table_set = 1;
> +
> +	ssd130x->seg_remap = !device_property_read_bool(dev, "solomon,segment-no-remap");
> +	ssd130x->com_seq = device_property_read_bool(dev, "solomon,com-seq");
> +	ssd130x->com_lrremap = device_property_read_bool(dev, "solomon,com-lrremap");
> +	ssd130x->com_invdir = device_property_read_bool(dev, "solomon,com-invdir");
> +	ssd130x->area_color_enable =
> +		device_property_read_bool(dev, "solomon,area-color-enable");
> +	ssd130x->low_power = device_property_read_bool(dev, "solomon,low-power");
> +
> +	ssd130x->contrast = 127;
> +	ssd130x->vcomh = ssd130x->device_info->default_vcomh;
> +
> +	/* Setup display timing */
> +	if (device_property_read_u32(dev, "solomon,dclk-div", &ssd130x->dclk_div))
> +		ssd130x->dclk_div = ssd130x->device_info->default_dclk_div;
> +	if (device_property_read_u32(dev, "solomon,dclk-frq", &ssd130x->dclk_frq))
> +		ssd130x->dclk_frq = ssd130x->device_info->default_dclk_frq;
> +}
> +
> +static int ssd130x_init_modeset(struct ssd130x_device *ssd130x)
> +{
> +	struct drm_display_mode *mode = &ssd130x->mode;
> +	struct device *dev = ssd130x->dev;
> +	struct drm_device *drm = &ssd130x->drm;
> +	unsigned long max_width, max_height;
> +	int ret;
> +
> +	ret = drmm_mode_config_init(drm);
> +	if (ret) {
> +		dev_err(dev, "DRM mode config init failed: %d\n", ret);
> +		return ret;
> +	}
> +
> +	mode->type = DRM_MODE_TYPE_DRIVER;
> +	mode->clock = 1;
> +	mode->hdisplay = mode->htotal = ssd130x->width;
> +	mode->hsync_start = mode->hsync_end = ssd130x->width;
> +	mode->vdisplay = mode->vtotal = ssd130x->height;
> +	mode->vsync_start = mode->vsync_end = ssd130x->height;
> +	mode->width_mm = 27;
> +	mode->height_mm = 27;
> +
> +	max_width = max_t(unsigned long, mode->hdisplay, DRM_SHADOW_PLANE_MAX_WIDTH);
> +	max_height = max_t(unsigned long, mode->vdisplay, DRM_SHADOW_PLANE_MAX_HEIGHT);
> +
> +	drm->mode_config.min_width = mode->hdisplay;
> +	drm->mode_config.max_width = max_width;
> +	drm->mode_config.min_height = mode->vdisplay;
> +	drm->mode_config.max_height = max_height;
> +	drm->mode_config.preferred_depth = 32;
> +	drm->mode_config.funcs = &ssd130x_mode_config_funcs;
> +
> +	ret = drm_connector_init(drm, &ssd130x->connector, &ssd130x_connector_funcs,
> +				 DRM_MODE_CONNECTOR_Unknown);
> +	if (ret) {
> +		dev_err(dev, "DRM connector init failed: %d\n", ret);
> +		return ret;
> +	}
> +
> +	drm_connector_helper_add(&ssd130x->connector, &ssd130x_connector_helper_funcs);
> +
> +	ret = drm_simple_display_pipe_init(drm, &ssd130x->pipe, &ssd130x_pipe_funcs,
> +					   ssd130x_formats, ARRAY_SIZE(ssd130x_formats),
> +					   NULL, &ssd130x->connector);
> +	if (ret) {
> +		dev_err(dev, "DRM simple display pipeline init failed: %d\n", ret);
> +		return ret;
> +	}
> +
> +	drm_plane_enable_fb_damage_clips(&ssd130x->pipe.plane);
> +
> +	drm_mode_config_reset(drm);
> +
> +	return 0;
> +}
> +
> +static int ssd130x_get_resources(struct ssd130x_device *ssd130x)
> +{
> +	struct device *dev = ssd130x->dev;
> +
> +	ssd130x->reset = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_LOW);
> +	if (IS_ERR(ssd130x->reset))
> +		return dev_err_probe(dev, PTR_ERR(ssd130x->reset),
> +				     "Failed to get reset gpio\n");
> +
> +	ssd130x->vcc_reg = devm_regulator_get(dev, "vcc");
> +	if (IS_ERR(ssd130x->vcc_reg))
> +		return dev_err_probe(dev, PTR_ERR(ssd130x->vcc_reg),
> +				     "Failed to get VCC regulator\n");
> +
> +	return 0;
> +}
> +
> +struct ssd130x_device *ssd130x_probe(struct device *dev, struct regmap *regmap)
> +{
> +	struct ssd130x_device *ssd130x;
> +	struct backlight_device *bl;
> +	struct drm_device *drm;
> +	int ret;
> +
> +	ssd130x = devm_drm_dev_alloc(dev, &ssd130x_drm_driver,
> +				     struct ssd130x_device, drm);
> +	if (IS_ERR(ssd130x)) {
> +		dev_err_probe(dev, PTR_ERR(ssd130x),
> +			      "Failed to allocate DRM device\n");
> +		return ssd130x;
> +	}
> +
> +	drm = &ssd130x->drm;
> +
> +	ssd130x->dev = dev;
> +	ssd130x->regmap = regmap;
> +	ssd130x->device_info = device_get_match_data(dev);
> +
> +	ssd130x_parse_properties(ssd130x);
> +
> +	ret = ssd130x_get_resources(ssd130x);
> +	if (ret)
> +		return ERR_PTR(ret);
> +
> +	bl = devm_backlight_device_register(dev, dev_name(dev), dev, ssd130x,
> +					    &ssd130xfb_bl_ops, NULL);
> +	if (IS_ERR(bl)) {
> +		ret = PTR_ERR(bl);
> +		dev_err_probe(dev, ret, "Unable to register backlight device\n");
> +		return ERR_PTR(ret);
> +	}
> +
> +	bl->props.brightness = ssd130x->contrast;
> +	bl->props.max_brightness = MAX_CONTRAST;
> +	ssd130x->bl_dev = bl;
> +
> +	ret = ssd130x_init_modeset(ssd130x);
> +	if (ret)
> +		return ERR_PTR(ret);
> +
> +	ret = drm_dev_register(drm, 0);
> +	if (ret) {
> +		dev_err_probe(dev, ret, "DRM device register failed\n");
> +		return ERR_PTR(ret);
> +	}
> +
> +	drm_fbdev_generic_setup(drm, 0);
> +
> +	return ssd130x;
> +}
> +EXPORT_SYMBOL_GPL(ssd130x_probe);
> +
> +int ssd130x_remove(struct ssd130x_device *ssd130x)
> +{
> +	drm_dev_unplug(&ssd130x->drm);
> +
> +	return 0;
> +}
> +EXPORT_SYMBOL_GPL(ssd130x_remove);
> +
> +void ssd130x_shutdown(struct ssd130x_device *ssd130x)
> +{
> +	drm_atomic_helper_shutdown(&ssd130x->drm);
> +}
> +EXPORT_SYMBOL_GPL(ssd130x_shutdown);
> +
> +MODULE_DESCRIPTION(DRIVER_DESC);
> +MODULE_AUTHOR("Javier Martinez Canillas <javierm@redhat.com>");
> +MODULE_LICENSE("GPL v2");
> diff --git a/drivers/gpu/drm/solomon/ssd130x.h b/drivers/gpu/drm/solomon/ssd130x.h
> new file mode 100644
> index 000000000000..754953b261b0
> --- /dev/null
> +++ b/drivers/gpu/drm/solomon/ssd130x.h
> @@ -0,0 +1,76 @@
> +/* SPDX-License-Identifier: GPL-2.0-only */
> +/*
> + * Header file for:
> + * DRM driver for Solomon SSD130x OLED displays
> + *
> + * Copyright 2022 Red Hat Inc.
> + * Authors: Javier Martinez Canillas <javierm@redhat.com>
> + *
> + * Based on drivers/video/fbdev/ssd1307fb.c
> + * Copyright 2012 Free Electrons
> + */
> +
> +#ifndef __SSD1307X_H__
> +#define __SSD1307X_H__
> +
> +#include <drm/drm_drv.h>
> +#include <drm/drm_simple_kms_helper.h>
> +
> +#include <linux/regmap.h>
> +
> +struct ssd130x_deviceinfo {
> +	u32 default_vcomh;
> +	u32 default_dclk_div;
> +	u32 default_dclk_frq;
> +	int need_pwm;
> +	int need_chargepump;
> +};
> +
> +struct ssd130x_device {
> +	struct drm_device drm;
> +	struct device *dev;
> +	struct drm_simple_display_pipe pipe;
> +	struct drm_display_mode mode;
> +	struct drm_connector connector;
> +	struct i2c_client *client;
> +
> +	struct regmap *regmap;
> +
> +	const struct ssd130x_deviceinfo *device_info;
> +
> +	unsigned area_color_enable : 1;
> +	unsigned com_invdir : 1;
> +	unsigned com_lrremap : 1;
> +	unsigned com_seq : 1;
> +	unsigned lookup_table_set : 1;
> +	unsigned low_power : 1;
> +	unsigned seg_remap : 1;
> +	u32 com_offset;
> +	u32 contrast;
> +	u32 dclk_div;
> +	u32 dclk_frq;
> +	u32 height;
> +	u8 lookup_table[4];
> +	u32 page_offset;
> +	u32 col_offset;
> +	u32 prechargep1;
> +	u32 prechargep2;
> +
> +	struct backlight_device *bl_dev;
> +	struct pwm_device *pwm;
> +	struct gpio_desc *reset;
> +	struct regulator *vcc_reg;
> +	u32 vcomh;
> +	u32 width;
> +	/* Cached address ranges */
> +	u8 col_start;
> +	u8 col_end;
> +	u8 page_start;
> +	u8 page_end;
> +};
> +
> +struct ssd130x_device *ssd130x_probe(struct device *dev, struct regmap *regmap);
> +int ssd130x_remove(struct ssd130x_device *ssd130x);
> +void ssd130x_shutdown(struct ssd130x_device *ssd130x);
> +
> +#endif /* __SSD1307X_H__ */
Andy Shevchenko Feb. 11, 2022, 3:49 p.m. UTC | #6
On Fri, Feb 11, 2022 at 01:05:57PM +0100, Javier Martinez Canillas wrote:
> On 2/11/22 12:33, Andy Shevchenko wrote:
> > On Fri, Feb 11, 2022 at 10:19:24AM +0100, Javier Martinez Canillas wrote:

...

> >> + * Helper to write command (SSD130X_COMMAND). The fist variadic argument
> >> + * is the command to write and the following are the command options.
> > 
> > This is not correct explanation. Please, rephrase to show that _each_ of the
> > options is sent with a preceding command.
> >
> 
> It's a correct explanation IMO from the caller point of view. The first argument
> is the command sent (i.e: SSD130X_SET_ADDRESS_MODE) and the next ones are the
> the command options (i.e: SSD130X_SET_ADDRESS_MODE_HORIZONTAL).
> 
> The fact that each command and options are preceding with a SSD130X_COMMAND
> value is part of the protocol of the device and a detail that's abstracted
> away by this helper function to the callers.

My previous suggestion about bulk transaction was purely based on this
(misinterpreted) description. Can we make sure somehow that another reader
don't trap into the same?

...


> >> +	bl = devm_backlight_device_register(dev, dev_name(dev), dev, ssd130x,
> >> +					    &ssd130xfb_bl_ops, NULL);
> >> +	if (IS_ERR(bl)) {
> > 
> >> +		ret = PTR_ERR(bl);
> >> +		dev_err_probe(dev, ret, "Unable to register backlight device\n");
> >> +		return ERR_PTR(ret);
> > 
> > 		dev_err_probe(dev, PTR_ERR(bl), "Unable to register backlight device\n");
> > 		return bl;
> > 
> > ?
> 
> No, because this function's return value is a struct ssd130x_device pointer,
> not a struct backlight_device pointer.

	return ERR_CAST(bl);
diff mbox series

Patch

diff --git a/drivers/gpu/drm/Kconfig b/drivers/gpu/drm/Kconfig
index dfdd3ec5f793..763355330b17 100644
--- a/drivers/gpu/drm/Kconfig
+++ b/drivers/gpu/drm/Kconfig
@@ -403,6 +403,8 @@  source "drivers/gpu/drm/xlnx/Kconfig"
 
 source "drivers/gpu/drm/gud/Kconfig"
 
+source "drivers/gpu/drm/solomon/Kconfig"
+
 source "drivers/gpu/drm/sprd/Kconfig"
 
 config DRM_HYPERV
diff --git a/drivers/gpu/drm/Makefile b/drivers/gpu/drm/Makefile
index 8675c2af7ae1..c2ef5f9fce54 100644
--- a/drivers/gpu/drm/Makefile
+++ b/drivers/gpu/drm/Makefile
@@ -132,4 +132,5 @@  obj-$(CONFIG_DRM_TIDSS) += tidss/
 obj-y			+= xlnx/
 obj-y			+= gud/
 obj-$(CONFIG_DRM_HYPERV) += hyperv/
+obj-y			+= solomon/
 obj-$(CONFIG_DRM_SPRD) += sprd/
diff --git a/drivers/gpu/drm/solomon/Kconfig b/drivers/gpu/drm/solomon/Kconfig
new file mode 100644
index 000000000000..7720a7039e8d
--- /dev/null
+++ b/drivers/gpu/drm/solomon/Kconfig
@@ -0,0 +1,12 @@ 
+config DRM_SSD130X
+	tristate "DRM support for Solomon SSD130x OLED displays"
+	depends on DRM
+	select BACKLIGHT_CLASS_DEVICE
+	select DRM_GEM_SHMEM_HELPER
+	select DRM_KMS_HELPER
+	help
+	  DRM driver for the SSD1305, SSD1306, SSD1307 and SSD1309 Solomon
+	  OLED controllers. This is only for the core driver, a driver for
+	  the appropriate bus transport in your chip also must be selected.
+
+	  If M is selected the module will be called ssd130x.
diff --git a/drivers/gpu/drm/solomon/Makefile b/drivers/gpu/drm/solomon/Makefile
new file mode 100644
index 000000000000..f685addb19fe
--- /dev/null
+++ b/drivers/gpu/drm/solomon/Makefile
@@ -0,0 +1 @@ 
+obj-$(CONFIG_DRM_SSD130X)	+= ssd130x.o
diff --git a/drivers/gpu/drm/solomon/ssd130x.c b/drivers/gpu/drm/solomon/ssd130x.c
new file mode 100644
index 000000000000..e17cf52b222e
--- /dev/null
+++ b/drivers/gpu/drm/solomon/ssd130x.c
@@ -0,0 +1,852 @@ 
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * DRM driver for Solomon SSD130x OLED displays
+ *
+ * Copyright 2022 Red Hat Inc.
+ * Author: Javier Martinez Canillas <javierm@redhat.com>
+ *
+ * Based on drivers/video/fbdev/ssd1307fb.c
+ * Copyright 2012 Free Electrons
+ */
+
+#include <linux/backlight.h>
+#include <linux/bitfield.h>
+#include <linux/delay.h>
+#include <linux/gpio/consumer.h>
+#include <linux/property.h>
+#include <linux/pwm.h>
+#include <linux/regulator/consumer.h>
+
+#include <drm/drm_atomic_helper.h>
+#include <drm/drm_damage_helper.h>
+#include <drm/drm_fb_cma_helper.h>
+#include <drm/drm_fb_helper.h>
+#include <drm/drm_format_helper.h>
+#include <drm/drm_gem_atomic_helper.h>
+#include <drm/drm_gem_framebuffer_helper.h>
+#include <drm/drm_gem_shmem_helper.h>
+#include <drm/drm_managed.h>
+#include <drm/drm_modes.h>
+#include <drm/drm_rect.h>
+#include <drm/drm_probe_helper.h>
+
+#include "ssd130x.h"
+
+#define DRIVER_NAME	"ssd130x"
+#define DRIVER_DESC	"DRM driver for Solomon SSD130x OLED displays"
+#define DRIVER_DATE	"20220131"
+#define DRIVER_MAJOR	1
+#define DRIVER_MINOR	0
+
+#define SSD130X_DATA				0x40
+#define SSD130X_COMMAND				0x80
+
+#define SSD130X_SET_ADDRESS_MODE		0x20
+#define SSD130X_SET_COL_RANGE			0x21
+#define SSD130X_SET_PAGE_RANGE			0x22
+#define SSD130X_CONTRAST			0x81
+#define SSD130X_SET_LOOKUP_TABLE		0x91
+#define SSD130X_CHARGE_PUMP			0x8d
+#define SSD130X_SEG_REMAP_ON			0xa1
+#define SSD130X_DISPLAY_OFF			0xae
+#define SSD130X_SET_MULTIPLEX_RATIO		0xa8
+#define SSD130X_DISPLAY_ON			0xaf
+#define SSD130X_START_PAGE_ADDRESS		0xb0
+#define SSD130X_SET_COM_SCAN_DIR		0xc0
+#define SSD130X_SET_DISPLAY_OFFSET		0xd3
+#define SSD130X_SET_CLOCK_FREQ			0xd5
+#define SSD130X_SET_AREA_COLOR_MODE		0xd8
+#define SSD130X_SET_PRECHARGE_PERIOD		0xd9
+#define SSD130X_SET_COM_PINS_CONFIG		0xda
+#define SSD130X_SET_VCOMH			0xdb
+
+#define SSD130X_SET_COM_SCAN_DIR_MASK		GENMASK(3, 2)
+#define SSD130X_SET_COM_SCAN_DIR_SET(val)	FIELD_PREP(SSD130X_SET_COM_SCAN_DIR_MASK, (val))
+#define SSD130X_SET_CLOCK_DIV_MASK		GENMASK(3, 0)
+#define SSD130X_SET_CLOCK_DIV_SET(val)		FIELD_PREP(SSD130X_SET_CLOCK_DIV_MASK, (val))
+#define SSD130X_SET_CLOCK_FREQ_MASK		GENMASK(7, 4)
+#define SSD130X_SET_CLOCK_FREQ_SET(val)		FIELD_PREP(SSD130X_SET_CLOCK_FREQ_MASK, (val))
+#define SSD130X_SET_PRECHARGE_PERIOD1_MASK	GENMASK(3, 0)
+#define SSD130X_SET_PRECHARGE_PERIOD1_SET(val)	FIELD_PREP(SSD130X_SET_PRECHARGE_PERIOD1_MASK, (val))
+#define SSD130X_SET_PRECHARGE_PERIOD2_MASK	GENMASK(7, 4)
+#define SSD130X_SET_PRECHARGE_PERIOD2_SET(val)	FIELD_PREP(SSD130X_SET_PRECHARGE_PERIOD2_MASK, (val))
+#define SSD130X_SET_COM_PINS_CONFIG1_MASK	GENMASK(4, 4)
+#define SSD130X_SET_COM_PINS_CONFIG1_SET(val)	FIELD_PREP(SSD130X_SET_COM_PINS_CONFIG1_MASK, (!val))
+#define SSD130X_SET_COM_PINS_CONFIG2_MASK	GENMASK(5, 5)
+#define SSD130X_SET_COM_PINS_CONFIG2_SET(val)	FIELD_PREP(SSD130X_SET_COM_PINS_CONFIG2_MASK, (val))
+
+#define SSD130X_SET_ADDRESS_MODE_HORIZONTAL	(0x00)
+#define SSD130X_SET_ADDRESS_MODE_VERTICAL	(0x01)
+#define SSD130X_SET_ADDRESS_MODE_PAGE		(0x02)
+
+#define SSD130X_SET_AREA_COLOR_MODE_ENABLE	(0x1e)
+#define SSD130X_SET_AREA_COLOR_MODE_LOW_POWER	(0x05)
+
+#define MAX_CONTRAST 255
+
+static inline struct ssd130x_device *drm_to_ssd130x(struct drm_device *drm)
+{
+	return container_of(drm, struct ssd130x_device, drm);
+}
+
+/*
+ * Helper to write data (SSD130X_DATA) to the device.
+ */
+static int ssd130x_write_data(struct ssd130x_device *ssd130x, u8 *values, int count)
+{
+	int ret;
+
+	ret = regmap_bulk_write(ssd130x->regmap, SSD130X_DATA, values, count);
+	if (ret)
+		return ret;
+
+	return 0;
+}
+
+/*
+ * Helper to write command (SSD130X_COMMAND). The fist variadic argument
+ * is the command to write and the following are the command options.
+ */
+static int ssd130x_write_cmd(struct ssd130x_device *ssd130x, int count,
+				    /* u8 cmd, u8 option, ... */...)
+{
+	va_list ap;
+	u8 value;
+	int ret;
+
+	va_start(ap, count);
+
+	do {
+		value = va_arg(ap, int);
+		ret = regmap_write(ssd130x->regmap, SSD130X_COMMAND, (u8)value);
+		if (ret)
+			goto out_end;
+	} while (--count);
+
+out_end:
+	va_end(ap);
+
+	return ret;
+}
+
+static int ssd130x_set_col_range(struct ssd130x_device *ssd130x,
+				 u8 col_start, u8 cols)
+{
+	u8 col_end = col_start + cols - 1;
+	int ret;
+
+	if (col_start == ssd130x->col_start && col_end == ssd130x->col_end)
+		return 0;
+
+	ret = ssd130x_write_cmd(ssd130x, 3, SSD130X_SET_COL_RANGE, col_start, col_end);
+	if (ret < 0)
+		return ret;
+
+	ssd130x->col_start = col_start;
+	ssd130x->col_end = col_end;
+	return 0;
+}
+
+static int ssd130x_set_page_range(struct ssd130x_device *ssd130x,
+				  u8 page_start, u8 pages)
+{
+	u8 page_end = page_start + pages - 1;
+	int ret;
+
+	if (page_start == ssd130x->page_start && page_end == ssd130x->page_end)
+		return 0;
+
+	ret = ssd130x_write_cmd(ssd130x, 3, SSD130X_SET_PAGE_RANGE, page_start, page_end);
+	if (ret < 0)
+		return ret;
+
+	ssd130x->page_start = page_start;
+	ssd130x->page_end = page_end;
+	return 0;
+}
+
+static int ssd130x_pwm_enable(struct ssd130x_device *ssd130x)
+{
+	struct device *dev = ssd130x->dev;
+	struct pwm_state pwmstate;
+
+	ssd130x->pwm = pwm_get(dev, NULL);
+	if (IS_ERR(ssd130x->pwm)) {
+		dev_err(dev, "Could not get PWM from firmware description!\n");
+		return PTR_ERR(ssd130x->pwm);
+	}
+
+	pwm_init_state(ssd130x->pwm, &pwmstate);
+	pwm_set_relative_duty_cycle(&pwmstate, 50, 100);
+	pwm_apply_state(ssd130x->pwm, &pwmstate);
+
+	/* Enable the PWM */
+	pwm_enable(ssd130x->pwm);
+
+	dev_dbg(dev, "Using PWM%d with a %lluns period.\n",
+		ssd130x->pwm->pwm, pwm_get_period(ssd130x->pwm));
+
+	return 0;
+}
+
+static void ssd130x_reset(struct ssd130x_device *ssd130x)
+{
+	if (!ssd130x->reset)
+		return;
+
+	/* Reset the screen */
+	gpiod_set_value_cansleep(ssd130x->reset, 1);
+	udelay(4);
+	gpiod_set_value_cansleep(ssd130x->reset, 0);
+	udelay(4);
+}
+
+static int ssd130x_power_on(struct ssd130x_device *ssd130x)
+{
+	struct device *dev = ssd130x->dev;
+	int ret;
+
+	ssd130x_reset(ssd130x);
+
+	ret = regulator_enable(ssd130x->vcc_reg);
+	if (ret) {
+		dev_err(dev, "Failed to enable VCC: %d\n", ret);
+		return ret;
+	}
+
+	if (ssd130x->device_info->need_pwm) {
+		ret = ssd130x_pwm_enable(ssd130x);
+		if (ret) {
+			dev_err(dev, "Failed to enable PWM: %d\n", ret);
+			regulator_disable(ssd130x->vcc_reg);
+			return ret;
+		}
+	}
+
+	return 0;
+}
+
+static void ssd130x_power_off(struct ssd130x_device *ssd130x)
+{
+	if (ssd130x->device_info->need_pwm) {
+		pwm_disable(ssd130x->pwm);
+		pwm_put(ssd130x->pwm);
+	}
+
+	regulator_disable(ssd130x->vcc_reg);
+}
+
+static int ssd130x_init(struct ssd130x_device *ssd130x)
+{
+	u32 precharge, dclk, com_invdir, compins, chargepump;
+	int ret;
+
+	/* Set initial contrast */
+	ret = ssd130x_write_cmd(ssd130x, 2, SSD130X_CONTRAST, ssd130x->contrast);
+	if (ret < 0)
+		return ret;
+
+	/* Set segment re-map */
+	if (ssd130x->seg_remap) {
+		ret = ssd130x_write_cmd(ssd130x, 1, SSD130X_SEG_REMAP_ON);
+		if (ret < 0)
+			return ret;
+	}
+
+	/* Set COM direction */
+	com_invdir = (SSD130X_SET_COM_SCAN_DIR |
+		      SSD130X_SET_COM_SCAN_DIR_SET(ssd130x->com_invdir));
+	ret = ssd130x_write_cmd(ssd130x,  1, com_invdir);
+	if (ret < 0)
+		return ret;
+
+	/* Set multiplex ratio value */
+	ret = ssd130x_write_cmd(ssd130x, 2, SSD130X_SET_MULTIPLEX_RATIO, ssd130x->height - 1);
+	if (ret < 0)
+		return ret;
+
+	/* set display offset value */
+	ret = ssd130x_write_cmd(ssd130x, 2, SSD130X_SET_DISPLAY_OFFSET, ssd130x->com_offset);
+	if (ret < 0)
+		return ret;
+
+	/* Set clock frequency */
+	dclk = (SSD130X_SET_CLOCK_DIV_SET(ssd130x->dclk_div - 1) |
+		SSD130X_SET_CLOCK_FREQ_SET(ssd130x->dclk_frq));
+	ret = ssd130x_write_cmd(ssd130x, 2, SSD130X_SET_CLOCK_FREQ, dclk);
+	if (ret < 0)
+		return ret;
+
+	/* Set Area Color Mode ON/OFF & Low Power Display Mode */
+	if (ssd130x->area_color_enable || ssd130x->low_power) {
+		u32 mode = 0;
+
+		if (ssd130x->area_color_enable)
+			mode |= SSD130X_SET_AREA_COLOR_MODE_ENABLE;
+
+		if (ssd130x->low_power)
+			mode |= SSD130X_SET_AREA_COLOR_MODE_LOW_POWER;
+
+		ret = ssd130x_write_cmd(ssd130x, 2, SSD130X_SET_AREA_COLOR_MODE, mode);
+		if (ret < 0)
+			return ret;
+	}
+
+	/* Set precharge period in number of ticks from the internal clock */
+	precharge = (SSD130X_SET_PRECHARGE_PERIOD1_SET(ssd130x->prechargep1) |
+		     SSD130X_SET_PRECHARGE_PERIOD1_SET(ssd130x->prechargep2));
+	ret = ssd130x_write_cmd(ssd130x, 2, SSD130X_SET_PRECHARGE_PERIOD, precharge);
+	if (ret < 0)
+		return ret;
+
+	/* Set COM pins configuration */
+	compins = BIT(1);
+	compins |= (SSD130X_SET_COM_PINS_CONFIG1_SET(ssd130x->com_seq) |
+		    SSD130X_SET_COM_PINS_CONFIG2_SET(ssd130x->com_lrremap));
+	ret = ssd130x_write_cmd(ssd130x, 2, SSD130X_SET_COM_PINS_CONFIG, compins);
+	if (ret < 0)
+		return ret;
+
+
+	/* Set VCOMH */
+	ret = ssd130x_write_cmd(ssd130x, 2, SSD130X_SET_VCOMH, ssd130x->vcomh);
+	if (ret < 0)
+		return ret;
+
+	/* Turn on the DC-DC Charge Pump */
+	chargepump = BIT(4);
+
+	if (ssd130x->device_info->need_chargepump)
+		chargepump |= BIT(2);
+
+	ret = ssd130x_write_cmd(ssd130x, 2, SSD130X_CHARGE_PUMP, chargepump);
+	if (ret < 0)
+		return ret;
+
+	/* Set lookup table */
+	if (ssd130x->lookup_table_set) {
+		int i;
+
+		ret = ssd130x_write_cmd(ssd130x, 1, SSD130X_SET_LOOKUP_TABLE);
+		if (ret < 0)
+			return ret;
+
+		for (i = 0; i < ARRAY_SIZE(ssd130x->lookup_table); i++) {
+			u8 val = ssd130x->lookup_table[i];
+
+			if (val < 31 || val > 63)
+				dev_warn(ssd130x->dev,
+					 "lookup table index %d value out of range 31 <= %d <= 63\n",
+					 i, val);
+			ret = ssd130x_write_cmd(ssd130x, 1, val);
+			if (ret < 0)
+				return ret;
+		}
+	}
+
+	/* Switch to horizontal addressing mode */
+	return ssd130x_write_cmd(ssd130x, 2, SSD130X_SET_ADDRESS_MODE,
+				 SSD130X_SET_ADDRESS_MODE_HORIZONTAL);
+}
+
+static int ssd130x_update_rect(struct ssd130x_device *ssd130x, u8 *buf,
+			       struct drm_rect *rect)
+{
+	unsigned int x = rect->x1;
+	unsigned int y = rect->y1;
+	unsigned int width = drm_rect_width(rect);
+	unsigned int height = drm_rect_height(rect);
+	unsigned int line_length = DIV_ROUND_UP(width, 8);
+	unsigned int pages = DIV_ROUND_UP(y % 8 + height, 8);
+	u32 array_idx = 0;
+	int ret, i, j, k;
+	u8 *data_array = NULL;
+
+	data_array = kcalloc(width, pages, GFP_KERNEL);
+	if (!data_array)
+		return -ENOMEM;
+
+	/*
+	 * The screen is divided in pages, each having a height of 8
+	 * pixels, and the width of the screen. When sending a byte of
+	 * data to the controller, it gives the 8 bits for the current
+	 * column. I.e, the first byte are the 8 bits of the first
+	 * column, then the 8 bits for the second column, etc.
+	 *
+	 *
+	 * Representation of the screen, assuming it is 5 bits
+	 * wide. Each letter-number combination is a bit that controls
+	 * one pixel.
+	 *
+	 * A0 A1 A2 A3 A4
+	 * B0 B1 B2 B3 B4
+	 * C0 C1 C2 C3 C4
+	 * D0 D1 D2 D3 D4
+	 * E0 E1 E2 E3 E4
+	 * F0 F1 F2 F3 F4
+	 * G0 G1 G2 G3 G4
+	 * H0 H1 H2 H3 H4
+	 *
+	 * If you want to update this screen, you need to send 5 bytes:
+	 *  (1) A0 B0 C0 D0 E0 F0 G0 H0
+	 *  (2) A1 B1 C1 D1 E1 F1 G1 H1
+	 *  (3) A2 B2 C2 D2 E2 F2 G2 H2
+	 *  (4) A3 B3 C3 D3 E3 F3 G3 H3
+	 *  (5) A4 B4 C4 D4 E4 F4 G4 H4
+	 */
+
+	ret = ssd130x_set_col_range(ssd130x, ssd130x->col_offset + x, width);
+	if (ret < 0)
+		goto out_free;
+
+	ret = ssd130x_set_page_range(ssd130x, ssd130x->page_offset + y / 8, pages);
+	if (ret < 0)
+		goto out_free;
+
+	for (i = y / 8; i < y / 8 + pages; i++) {
+		int m = 8;
+
+		/* Last page may be partial */
+		if (8 * (i + 1) > ssd130x->height)
+			m = ssd130x->height % 8;
+		for (j = x; j < x + width; j++) {
+			u8 data = 0;
+
+			for (k = 0; k < m; k++) {
+				u8 byte = buf[(8 * i + k) * line_length + j / 8];
+				u8 bit = (byte >> (j % 8)) & 1;
+
+				data |= bit << k;
+			}
+			data_array[array_idx++] = data;
+		}
+	}
+
+	ret = ssd130x_write_data(ssd130x, data_array, width * pages);
+
+out_free:
+	kfree(data_array);
+	return ret;
+}
+
+static void ssd130x_clear_screen(struct ssd130x_device *ssd130x)
+{
+	u8 *buf = NULL;
+	struct drm_rect fullscreen = {
+		.x1 = 0,
+		.x2 = ssd130x->width,
+		.y1 = 0,
+		.y2 = ssd130x->height,
+	};
+
+	buf = kcalloc(ssd130x->width, ssd130x->height, GFP_KERNEL);
+	if (!buf)
+		return;
+
+	ssd130x_update_rect(ssd130x, buf, &fullscreen);
+
+	kfree(buf);
+}
+
+static int ssd130x_fb_blit_rect(struct drm_framebuffer *fb, const struct dma_buf_map *map,
+				struct drm_rect *rect)
+{
+	struct ssd130x_device *ssd130x = drm_to_ssd130x(fb->dev);
+	void *vmap = map->vaddr; /* TODO: Use mapping abstraction properly */
+	int ret = 0;
+	u8 *buf = NULL;
+
+	buf = kcalloc(fb->width, fb->height, GFP_KERNEL);
+	if (!buf)
+		return -ENOMEM;
+
+	drm_fb_xrgb8888_to_mono_reversed(buf, 0, vmap, fb, rect);
+
+	ssd130x_update_rect(ssd130x, buf, rect);
+
+	kfree(buf);
+
+	return ret;
+}
+
+static int ssd130x_display_pipe_mode_valid(struct drm_simple_display_pipe *pipe,
+					   const struct drm_display_mode *mode)
+{
+	struct ssd130x_device *ssd130x = drm_to_ssd130x(pipe->crtc.dev);
+
+	if (mode->hdisplay != ssd130x->mode.hdisplay &&
+	    mode->vdisplay != ssd130x->mode.vdisplay)
+		return MODE_ONE_SIZE;
+
+	if (mode->hdisplay != ssd130x->mode.hdisplay)
+		return MODE_ONE_WIDTH;
+
+	if (mode->vdisplay != ssd130x->mode.vdisplay)
+		return MODE_ONE_HEIGHT;
+
+	return MODE_OK;
+}
+
+static void ssd130x_display_pipe_enable(struct drm_simple_display_pipe *pipe,
+					struct drm_crtc_state *crtc_state,
+					struct drm_plane_state *plane_state)
+{
+	struct ssd130x_device *ssd130x = drm_to_ssd130x(pipe->crtc.dev);
+	struct drm_device *drm = &ssd130x->drm;
+	int idx, ret;
+
+	ret = ssd130x_power_on(ssd130x);
+	if (ret)
+		return;
+
+	ret = ssd130x_init(ssd130x);
+	if (ret)
+		goto out_power_off;
+
+	if (!drm_dev_enter(drm, &idx))
+		goto out_power_off;
+
+	ssd130x_clear_screen(ssd130x);
+
+	ssd130x_write_cmd(ssd130x, 1, SSD130X_DISPLAY_ON);
+
+	backlight_enable(ssd130x->bl_dev);
+
+	drm_dev_exit(idx);
+
+	return;
+out_power_off:
+	ssd130x_power_off(ssd130x);
+}
+
+static void ssd130x_display_pipe_disable(struct drm_simple_display_pipe *pipe)
+{
+	struct ssd130x_device *ssd130x = drm_to_ssd130x(pipe->crtc.dev);
+	struct drm_device *drm = &ssd130x->drm;
+	int idx;
+
+	if (!drm_dev_enter(drm, &idx))
+		return;
+
+	ssd130x_clear_screen(ssd130x);
+
+	backlight_disable(ssd130x->bl_dev);
+
+	ssd130x_write_cmd(ssd130x, 1, SSD130X_DISPLAY_OFF);
+
+	ssd130x_power_off(ssd130x);
+
+	drm_dev_exit(idx);
+}
+
+static void ssd130x_display_pipe_update(struct drm_simple_display_pipe *pipe,
+					struct drm_plane_state *old_plane_state)
+{
+	struct ssd130x_device *ssd130x = drm_to_ssd130x(pipe->crtc.dev);
+	struct drm_plane_state *plane_state = pipe->plane.state;
+	struct drm_shadow_plane_state *shadow_plane_state = to_drm_shadow_plane_state(plane_state);
+	struct drm_framebuffer *fb = plane_state->fb;
+	struct drm_device *drm = &ssd130x->drm;
+	struct drm_rect src_clip, dst_clip;
+	int idx;
+
+	if (!fb)
+		return;
+
+	if (!pipe->crtc.state->active)
+		return;
+
+	if (!drm_atomic_helper_damage_merged(old_plane_state, plane_state, &src_clip))
+		return;
+
+	dst_clip = plane_state->dst;
+	if (!drm_rect_intersect(&dst_clip, &src_clip))
+		return;
+
+	if (!drm_dev_enter(drm, &idx))
+		return;
+
+	ssd130x_fb_blit_rect(plane_state->fb, &shadow_plane_state->data[0], &dst_clip);
+
+	drm_dev_exit(idx);
+}
+
+static const struct drm_simple_display_pipe_funcs ssd130x_pipe_funcs = {
+	.mode_valid = ssd130x_display_pipe_mode_valid,
+	.enable = ssd130x_display_pipe_enable,
+	.disable = ssd130x_display_pipe_disable,
+	.update = ssd130x_display_pipe_update,
+	DRM_GEM_SIMPLE_DISPLAY_PIPE_SHADOW_PLANE_FUNCS,
+};
+
+static int ssd130x_connector_get_modes(struct drm_connector *connector)
+{
+	struct ssd130x_device *ssd130x = drm_to_ssd130x(connector->dev);
+	struct drm_display_mode *mode = &ssd130x->mode;
+	struct device *dev = ssd130x->dev;
+
+	mode = drm_mode_duplicate(connector->dev, &ssd130x->mode);
+	if (!mode) {
+		dev_err(dev, "Failed to duplicated mode\n");
+		return 0;
+	}
+
+	drm_mode_probed_add(connector, mode);
+	drm_set_preferred_mode(connector, mode->hdisplay, mode->vdisplay);
+
+	/* There is only a single mode */
+	return 1;
+}
+
+static const struct drm_connector_helper_funcs ssd130x_connector_helper_funcs = {
+	.get_modes = ssd130x_connector_get_modes,
+};
+
+static const struct drm_connector_funcs ssd130x_connector_funcs = {
+	.reset = drm_atomic_helper_connector_reset,
+	.fill_modes = drm_helper_probe_single_connector_modes,
+	.destroy = drm_connector_cleanup,
+	.atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state,
+	.atomic_destroy_state = drm_atomic_helper_connector_destroy_state,
+};
+
+static const struct drm_mode_config_funcs ssd130x_mode_config_funcs = {
+	.fb_create = drm_gem_fb_create_with_dirty,
+	.atomic_check = drm_atomic_helper_check,
+	.atomic_commit = drm_atomic_helper_commit,
+};
+
+static const uint32_t ssd130x_formats[] = {
+	DRM_FORMAT_XRGB8888,
+};
+
+DEFINE_DRM_GEM_FOPS(ssd130x_fops);
+
+static const struct drm_driver ssd130x_drm_driver = {
+	DRM_GEM_SHMEM_DRIVER_OPS,
+	.name			= DRIVER_NAME,
+	.desc			= DRIVER_DESC,
+	.date			= DRIVER_DATE,
+	.major			= DRIVER_MAJOR,
+	.minor			= DRIVER_MINOR,
+	.driver_features	= DRIVER_ATOMIC | DRIVER_GEM | DRIVER_MODESET,
+	.fops			= &ssd130x_fops,
+};
+
+static int ssd130x_update_bl(struct backlight_device *bdev)
+{
+	struct ssd130x_device *ssd130x = bl_get_data(bdev);
+	int brightness = backlight_get_brightness(bdev);
+	int ret;
+
+	ssd130x->contrast = brightness;
+
+	ret = ssd130x_write_cmd(ssd130x, 1, SSD130X_CONTRAST);
+	if (ret < 0)
+		return ret;
+
+	ret = ssd130x_write_cmd(ssd130x, 1, ssd130x->contrast);
+	if (ret < 0)
+		return ret;
+
+	return 0;
+}
+
+static const struct backlight_ops ssd130xfb_bl_ops = {
+	.update_status	= ssd130x_update_bl,
+};
+
+static void ssd130x_parse_properties(struct ssd130x_device *ssd130x)
+{
+	struct device *dev = ssd130x->dev;
+
+	if (device_property_read_u32(dev, "solomon,width", &ssd130x->width))
+		ssd130x->width = 96;
+
+	if (device_property_read_u32(dev, "solomon,height", &ssd130x->height))
+		ssd130x->height = 16;
+
+	if (device_property_read_u32(dev, "solomon,page-offset", &ssd130x->page_offset))
+		ssd130x->page_offset = 1;
+
+	if (device_property_read_u32(dev, "solomon,col-offset", &ssd130x->col_offset))
+		ssd130x->col_offset = 0;
+
+	if (device_property_read_u32(dev, "solomon,com-offset", &ssd130x->com_offset))
+		ssd130x->com_offset = 0;
+
+	if (device_property_read_u32(dev, "solomon,prechargep1", &ssd130x->prechargep1))
+		ssd130x->prechargep1 = 2;
+
+	if (device_property_read_u32(dev, "solomon,prechargep2", &ssd130x->prechargep2))
+		ssd130x->prechargep2 = 2;
+
+	if (!device_property_read_u8_array(dev, "solomon,lookup-table",
+					   ssd130x->lookup_table,
+					   ARRAY_SIZE(ssd130x->lookup_table)))
+		ssd130x->lookup_table_set = 1;
+
+	ssd130x->seg_remap = !device_property_read_bool(dev, "solomon,segment-no-remap");
+	ssd130x->com_seq = device_property_read_bool(dev, "solomon,com-seq");
+	ssd130x->com_lrremap = device_property_read_bool(dev, "solomon,com-lrremap");
+	ssd130x->com_invdir = device_property_read_bool(dev, "solomon,com-invdir");
+	ssd130x->area_color_enable =
+		device_property_read_bool(dev, "solomon,area-color-enable");
+	ssd130x->low_power = device_property_read_bool(dev, "solomon,low-power");
+
+	ssd130x->contrast = 127;
+	ssd130x->vcomh = ssd130x->device_info->default_vcomh;
+
+	/* Setup display timing */
+	if (device_property_read_u32(dev, "solomon,dclk-div", &ssd130x->dclk_div))
+		ssd130x->dclk_div = ssd130x->device_info->default_dclk_div;
+	if (device_property_read_u32(dev, "solomon,dclk-frq", &ssd130x->dclk_frq))
+		ssd130x->dclk_frq = ssd130x->device_info->default_dclk_frq;
+}
+
+static int ssd130x_init_modeset(struct ssd130x_device *ssd130x)
+{
+	struct drm_display_mode *mode = &ssd130x->mode;
+	struct device *dev = ssd130x->dev;
+	struct drm_device *drm = &ssd130x->drm;
+	unsigned long max_width, max_height;
+	int ret;
+
+	ret = drmm_mode_config_init(drm);
+	if (ret) {
+		dev_err(dev, "DRM mode config init failed: %d\n", ret);
+		return ret;
+	}
+
+	mode->type = DRM_MODE_TYPE_DRIVER;
+	mode->clock = 1;
+	mode->hdisplay = mode->htotal = ssd130x->width;
+	mode->hsync_start = mode->hsync_end = ssd130x->width;
+	mode->vdisplay = mode->vtotal = ssd130x->height;
+	mode->vsync_start = mode->vsync_end = ssd130x->height;
+	mode->width_mm = 27;
+	mode->height_mm = 27;
+
+	max_width = max_t(unsigned long, mode->hdisplay, DRM_SHADOW_PLANE_MAX_WIDTH);
+	max_height = max_t(unsigned long, mode->vdisplay, DRM_SHADOW_PLANE_MAX_HEIGHT);
+
+	drm->mode_config.min_width = mode->hdisplay;
+	drm->mode_config.max_width = max_width;
+	drm->mode_config.min_height = mode->vdisplay;
+	drm->mode_config.max_height = max_height;
+	drm->mode_config.preferred_depth = 32;
+	drm->mode_config.funcs = &ssd130x_mode_config_funcs;
+
+	ret = drm_connector_init(drm, &ssd130x->connector, &ssd130x_connector_funcs,
+				 DRM_MODE_CONNECTOR_Unknown);
+	if (ret) {
+		dev_err(dev, "DRM connector init failed: %d\n", ret);
+		return ret;
+	}
+
+	drm_connector_helper_add(&ssd130x->connector, &ssd130x_connector_helper_funcs);
+
+	ret = drm_simple_display_pipe_init(drm, &ssd130x->pipe, &ssd130x_pipe_funcs,
+					   ssd130x_formats, ARRAY_SIZE(ssd130x_formats),
+					   NULL, &ssd130x->connector);
+	if (ret) {
+		dev_err(dev, "DRM simple display pipeline init failed: %d\n", ret);
+		return ret;
+	}
+
+	drm_plane_enable_fb_damage_clips(&ssd130x->pipe.plane);
+
+	drm_mode_config_reset(drm);
+
+	return 0;
+}
+
+static int ssd130x_get_resources(struct ssd130x_device *ssd130x)
+{
+	struct device *dev = ssd130x->dev;
+
+	ssd130x->reset = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_LOW);
+	if (IS_ERR(ssd130x->reset))
+		return dev_err_probe(dev, PTR_ERR(ssd130x->reset),
+				     "Failed to get reset gpio\n");
+
+	ssd130x->vcc_reg = devm_regulator_get(dev, "vcc");
+	if (IS_ERR(ssd130x->vcc_reg))
+		return dev_err_probe(dev, PTR_ERR(ssd130x->vcc_reg),
+				     "Failed to get VCC regulator\n");
+
+	return 0;
+}
+
+struct ssd130x_device *ssd130x_probe(struct device *dev, struct regmap *regmap)
+{
+	struct ssd130x_device *ssd130x;
+	struct backlight_device *bl;
+	struct drm_device *drm;
+	int ret;
+
+	ssd130x = devm_drm_dev_alloc(dev, &ssd130x_drm_driver,
+				     struct ssd130x_device, drm);
+	if (IS_ERR(ssd130x)) {
+		dev_err_probe(dev, PTR_ERR(ssd130x),
+			      "Failed to allocate DRM device\n");
+		return ssd130x;
+	}
+
+	drm = &ssd130x->drm;
+
+	ssd130x->dev = dev;
+	ssd130x->regmap = regmap;
+	ssd130x->device_info = device_get_match_data(dev);
+
+	ssd130x_parse_properties(ssd130x);
+
+	ret = ssd130x_get_resources(ssd130x);
+	if (ret)
+		return ERR_PTR(ret);
+
+	bl = devm_backlight_device_register(dev, dev_name(dev), dev, ssd130x,
+					    &ssd130xfb_bl_ops, NULL);
+	if (IS_ERR(bl)) {
+		ret = PTR_ERR(bl);
+		dev_err_probe(dev, ret, "Unable to register backlight device\n");
+		return ERR_PTR(ret);
+	}
+
+	bl->props.brightness = ssd130x->contrast;
+	bl->props.max_brightness = MAX_CONTRAST;
+	ssd130x->bl_dev = bl;
+
+	ret = ssd130x_init_modeset(ssd130x);
+	if (ret)
+		return ERR_PTR(ret);
+
+	ret = drm_dev_register(drm, 0);
+	if (ret) {
+		dev_err_probe(dev, ret, "DRM device register failed\n");
+		return ERR_PTR(ret);
+	}
+
+	drm_fbdev_generic_setup(drm, 0);
+
+	return ssd130x;
+}
+EXPORT_SYMBOL_GPL(ssd130x_probe);
+
+int ssd130x_remove(struct ssd130x_device *ssd130x)
+{
+	drm_dev_unplug(&ssd130x->drm);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(ssd130x_remove);
+
+void ssd130x_shutdown(struct ssd130x_device *ssd130x)
+{
+	drm_atomic_helper_shutdown(&ssd130x->drm);
+}
+EXPORT_SYMBOL_GPL(ssd130x_shutdown);
+
+MODULE_DESCRIPTION(DRIVER_DESC);
+MODULE_AUTHOR("Javier Martinez Canillas <javierm@redhat.com>");
+MODULE_LICENSE("GPL v2");
diff --git a/drivers/gpu/drm/solomon/ssd130x.h b/drivers/gpu/drm/solomon/ssd130x.h
new file mode 100644
index 000000000000..754953b261b0
--- /dev/null
+++ b/drivers/gpu/drm/solomon/ssd130x.h
@@ -0,0 +1,76 @@ 
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Header file for:
+ * DRM driver for Solomon SSD130x OLED displays
+ *
+ * Copyright 2022 Red Hat Inc.
+ * Authors: Javier Martinez Canillas <javierm@redhat.com>
+ *
+ * Based on drivers/video/fbdev/ssd1307fb.c
+ * Copyright 2012 Free Electrons
+ */
+
+#ifndef __SSD1307X_H__
+#define __SSD1307X_H__
+
+#include <drm/drm_drv.h>
+#include <drm/drm_simple_kms_helper.h>
+
+#include <linux/regmap.h>
+
+struct ssd130x_deviceinfo {
+	u32 default_vcomh;
+	u32 default_dclk_div;
+	u32 default_dclk_frq;
+	int need_pwm;
+	int need_chargepump;
+};
+
+struct ssd130x_device {
+	struct drm_device drm;
+	struct device *dev;
+	struct drm_simple_display_pipe pipe;
+	struct drm_display_mode mode;
+	struct drm_connector connector;
+	struct i2c_client *client;
+
+	struct regmap *regmap;
+
+	const struct ssd130x_deviceinfo *device_info;
+
+	unsigned area_color_enable : 1;
+	unsigned com_invdir : 1;
+	unsigned com_lrremap : 1;
+	unsigned com_seq : 1;
+	unsigned lookup_table_set : 1;
+	unsigned low_power : 1;
+	unsigned seg_remap : 1;
+	u32 com_offset;
+	u32 contrast;
+	u32 dclk_div;
+	u32 dclk_frq;
+	u32 height;
+	u8 lookup_table[4];
+	u32 page_offset;
+	u32 col_offset;
+	u32 prechargep1;
+	u32 prechargep2;
+
+	struct backlight_device *bl_dev;
+	struct pwm_device *pwm;
+	struct gpio_desc *reset;
+	struct regulator *vcc_reg;
+	u32 vcomh;
+	u32 width;
+	/* Cached address ranges */
+	u8 col_start;
+	u8 col_end;
+	u8 page_start;
+	u8 page_end;
+};
+
+struct ssd130x_device *ssd130x_probe(struct device *dev, struct regmap *regmap);
+int ssd130x_remove(struct ssd130x_device *ssd130x);
+void ssd130x_shutdown(struct ssd130x_device *ssd130x);
+
+#endif /* __SSD1307X_H__ */