[PATCH 0/3] Add DRM pixel blend mode support to R-Car DU

[PATCH 0/3] Add DRM pixel blend mode support to R-Car DU

[Takanari Hayama]

The series of patches adds support for DRM pixel blend mode to R-Car DU.
The current R-Car DU implicitly supports "Coverage" only.

Unfortunately, this changes the default blending mode of R-Car DU to
"Pre-multiplied" which is the default when pixel blend mode is
supported.

Takanari Hayama (3):
  media: vsp1: save pixel alpha info in vsp1_rwpf
  media: vsp1: add blend mode support
  drm: rcar-du: Add DRM blend mode support

 drivers/gpu/drm/rcar-du/rcar_du_vsp.c           | 17 +++++++++++++++++
 drivers/media/platform/renesas/vsp1/vsp1_drm.c  | 12 ++++++++++++
 drivers/media/platform/renesas/vsp1/vsp1_rpf.c  |  6 +++---
 drivers/media/platform/renesas/vsp1/vsp1_rwpf.h |  2 ++
 include/media/vsp1.h                            | 14 ++++++++++++++
 5 files changed, 48 insertions(+), 3 deletions(-)

-- 
2.25.1

[PATCH 1/3] media: vsp1: save pixel alpha info in vsp1_rwpf

[Takanari Hayama]

In order to support DRM blend mode, we need to able to override pixel
alpha flag. When DRM_MODE_BLEND_PIXEL_NONE is desired, we'd like to let
VSP1 to ignore the pixel alpha by overriding the flag.

Signed-off-by: Takanari Hayama <taki@igel.co.jp>
---
 drivers/media/platform/renesas/vsp1/vsp1_drm.c  | 1 +
 drivers/media/platform/renesas/vsp1/vsp1_rpf.c  | 6 +++---
 drivers/media/platform/renesas/vsp1/vsp1_rwpf.h | 2 ++
 3 files changed, 6 insertions(+), 3 deletions(-)

diff --git a/drivers/media/platform/renesas/vsp1/vsp1_drm.c b/drivers/media/platform/renesas/vsp1/vsp1_drm.c
index 0c2507dc03d6..9ec3ac835987 100644
--- a/drivers/media/platform/renesas/vsp1/vsp1_drm.c
+++ b/drivers/media/platform/renesas/vsp1/vsp1_drm.c
@@ -600,6 +600,7 @@ static int vsp1_du_pipeline_set_rwpf_format(struct vsp1_device *vsp1,
 	rwpf->format.num_planes = fmtinfo->planes;
 	rwpf->format.plane_fmt[0].bytesperline = pitch;
 	rwpf->format.plane_fmt[1].bytesperline = pitch / chroma_hsub;
+	rwpf->pixel_alpha = fmtinfo->alpha;
 
 	return 0;
 }
diff --git a/drivers/media/platform/renesas/vsp1/vsp1_rpf.c b/drivers/media/platform/renesas/vsp1/vsp1_rpf.c
index 75083cb234fe..e6bd813dc68c 100644
--- a/drivers/media/platform/renesas/vsp1/vsp1_rpf.c
+++ b/drivers/media/platform/renesas/vsp1/vsp1_rpf.c
@@ -152,13 +152,13 @@ static void rpf_configure_stream(struct vsp1_entity *entity,
 	 * In all cases, disable color keying.
 	 */
 	vsp1_rpf_write(rpf, dlb, VI6_RPF_ALPH_SEL, VI6_RPF_ALPH_SEL_AEXT_EXT |
-		       (fmtinfo->alpha ? VI6_RPF_ALPH_SEL_ASEL_PACKED
-				       : VI6_RPF_ALPH_SEL_ASEL_FIXED));
+		       (rpf->pixel_alpha ? VI6_RPF_ALPH_SEL_ASEL_PACKED
+					 : VI6_RPF_ALPH_SEL_ASEL_FIXED));
 
 	if (entity->vsp1->info->gen == 3) {
 		u32 mult;
 
-		if (fmtinfo->alpha) {
+		if (rpf->pixel_alpha) {
 			/*
 			 * When the input contains an alpha channel enable the
 			 * alpha multiplier. If the input is premultiplied we
diff --git a/drivers/media/platform/renesas/vsp1/vsp1_rwpf.h b/drivers/media/platform/renesas/vsp1/vsp1_rwpf.h
index eac5c04c2239..07ddebb78dfa 100644
--- a/drivers/media/platform/renesas/vsp1/vsp1_rwpf.h
+++ b/drivers/media/platform/renesas/vsp1/vsp1_rwpf.h
@@ -43,6 +43,8 @@ struct vsp1_rwpf {
 	const struct vsp1_format_info *fmtinfo;
 	unsigned int brx_input;
 
+	bool pixel_alpha;
+
 	unsigned int alpha;
 
 	u32 mult_alpha;
-- 
2.25.1

Re: [PATCH 1/3] media: vsp1: save pixel alpha info in vsp1_rwpf

[Laurent Pinchart]

Hello Hayama-san,

Thank you for the patch (and sorry for the long delay).

On Mon, Jul 04, 2022 at 11:52:29AM +0900, Takanari Hayama wrote:
> In order to support DRM blend mode, we need to able to override pixel
> alpha flag. When DRM_MODE_BLEND_PIXEL_NONE is desired, we'd like to let
> VSP1 to ignore the pixel alpha by overriding the flag.
> 
> Signed-off-by: Takanari Hayama <taki@igel.co.jp>
> ---
>  drivers/media/platform/renesas/vsp1/vsp1_drm.c  | 1 +
>  drivers/media/platform/renesas/vsp1/vsp1_rpf.c  | 6 +++---
>  drivers/media/platform/renesas/vsp1/vsp1_rwpf.h | 2 ++
>  3 files changed, 6 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/media/platform/renesas/vsp1/vsp1_drm.c b/drivers/media/platform/renesas/vsp1/vsp1_drm.c
> index 0c2507dc03d6..9ec3ac835987 100644
> --- a/drivers/media/platform/renesas/vsp1/vsp1_drm.c
> +++ b/drivers/media/platform/renesas/vsp1/vsp1_drm.c
> @@ -600,6 +600,7 @@ static int vsp1_du_pipeline_set_rwpf_format(struct vsp1_device *vsp1,
>  	rwpf->format.num_planes = fmtinfo->planes;
>  	rwpf->format.plane_fmt[0].bytesperline = pitch;
>  	rwpf->format.plane_fmt[1].bytesperline = pitch / chroma_hsub;
> +	rwpf->pixel_alpha = fmtinfo->alpha;
>  
>  	return 0;
>  }
> diff --git a/drivers/media/platform/renesas/vsp1/vsp1_rpf.c b/drivers/media/platform/renesas/vsp1/vsp1_rpf.c
> index 75083cb234fe..e6bd813dc68c 100644
> --- a/drivers/media/platform/renesas/vsp1/vsp1_rpf.c
> +++ b/drivers/media/platform/renesas/vsp1/vsp1_rpf.c
> @@ -152,13 +152,13 @@ static void rpf_configure_stream(struct vsp1_entity *entity,
>  	 * In all cases, disable color keying.
>  	 */
>  	vsp1_rpf_write(rpf, dlb, VI6_RPF_ALPH_SEL, VI6_RPF_ALPH_SEL_AEXT_EXT |
> -		       (fmtinfo->alpha ? VI6_RPF_ALPH_SEL_ASEL_PACKED
> -				       : VI6_RPF_ALPH_SEL_ASEL_FIXED));
> +		       (rpf->pixel_alpha ? VI6_RPF_ALPH_SEL_ASEL_PACKED
> +					 : VI6_RPF_ALPH_SEL_ASEL_FIXED));
>  
>  	if (entity->vsp1->info->gen == 3) {
>  		u32 mult;
>  
> -		if (fmtinfo->alpha) {
> +		if (rpf->pixel_alpha) {
>  			/*
>  			 * When the input contains an alpha channel enable the
>  			 * alpha multiplier. If the input is premultiplied we

From a DRM point of view this looks fine.
vsp1_du_pipeline_set_rwpf_format() is called upon .atomic_update(), and
rpf_configure_stream() upon .atomic_flush(), and every update is
guaranteed to be followed by a flush (through code paths that are way
too convoluted, but that's a story for a different day).

However, VSP instances that are exposed through V4L2 will see a
regression with this patch. rwpf->pixel_alpha will never be set, so
alpha-enabled formats will break. Several test case from
https://git.ideasonboard.com/renesas/vsp-tests.git report failures, for
instance

# ./vsp-unit-test-0001.sh
Testing WPF packing in RGB332: pass
Testing WPF packing in ARGB555: pass
Testing WPF packing in XRGB555: pass
Testing WPF packing in RGB565: pass
Testing WPF packing in BGR24: pass
Testing WPF packing in RGB24: pass
Testing WPF packing in ABGR32: fail
Testing WPF packing in ARGB32: fail
Testing WPF packing in XBGR32: pass
Testing WPF packing in XRGB32: pass

It seems that this could be fixed fairly easily by setting
rpf->pixel_alpha in vsp1_video_set_format():

diff --git a/drivers/media/platform/renesas/vsp1/vsp1_video.c b/drivers/media/platform/renesas/vsp1/vsp1_video.c
index 51219b1b6ea9..b518873d3280 100644
--- a/drivers/media/platform/renesas/vsp1/vsp1_video.c
+++ b/drivers/media/platform/renesas/vsp1/vsp1_video.c
@@ -1015,6 +1015,7 @@ vsp1_video_set_format(struct file *file, void *fh, struct v4l2_format *format)

 	video->rwpf->format = format->fmt.pix_mp;
 	video->rwpf->fmtinfo = info;
+	video->rwpf->pixel_alpha = info->alpha;

 done:
 	mutex_unlock(&video->lock);

I've tested that and it fixes the tests, so with this change,

Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

No need to submit a v2 if no other changes are needed in subsequent
patches, I can apply this change when merging the patches.

> diff --git a/drivers/media/platform/renesas/vsp1/vsp1_rwpf.h b/drivers/media/platform/renesas/vsp1/vsp1_rwpf.h
> index eac5c04c2239..07ddebb78dfa 100644
> --- a/drivers/media/platform/renesas/vsp1/vsp1_rwpf.h
> +++ b/drivers/media/platform/renesas/vsp1/vsp1_rwpf.h
> @@ -43,6 +43,8 @@ struct vsp1_rwpf {
>  	const struct vsp1_format_info *fmtinfo;
>  	unsigned int brx_input;
>  
> +	bool pixel_alpha;
> +
>  	unsigned int alpha;
>  
>  	u32 mult_alpha;

-- 
Regards,

Laurent Pinchart

[PATCH 2/3] media: vsp1: add blend mode support

[Takanari Hayama]

To support DRM blend mode in R-Car DU driver, we must add blend mode
support in VSP1. Although VSP1 hardware is capable to support all blend
mode defined in DRM, the current R-Car DU driver implicitly supports
DRM_MODE_BLEND_COVERAGE only.

We add a new property to vsp1_du_atomic_config, so that R-Car DU driver
can pass the desired blend mode.

Signed-off-by: Takanari Hayama <taki@igel.co.jp>
---
 drivers/media/platform/renesas/vsp1/vsp1_drm.c | 11 +++++++++++
 include/media/vsp1.h                           | 14 ++++++++++++++
 2 files changed, 25 insertions(+)

diff --git a/drivers/media/platform/renesas/vsp1/vsp1_drm.c b/drivers/media/platform/renesas/vsp1/vsp1_drm.c
index 9ec3ac835987..ed0cf552fce2 100644
--- a/drivers/media/platform/renesas/vsp1/vsp1_drm.c
+++ b/drivers/media/platform/renesas/vsp1/vsp1_drm.c
@@ -861,6 +861,17 @@ int vsp1_du_atomic_update(struct device *dev, unsigned int pipe_index,
 	vsp1->drm->inputs[rpf_index].compose = cfg->dst;
 	vsp1->drm->inputs[rpf_index].zpos = cfg->zpos;
 
+	switch (cfg->blend_mode) {
+	case VSP1_DU_BLEND_MODE_PREMULTI:
+		rpf->format.flags = V4L2_PIX_FMT_FLAG_PREMUL_ALPHA;
+		break;
+	case VSP1_DU_BLEND_MODE_PIXEL_NONE:
+		rpf->pixel_alpha = false;
+		fallthrough;
+	case VSP1_DU_BLEND_MODE_COVERAGE:
+		rpf->format.flags = 0;
+	}
+
 	drm_pipe->pipe.inputs[rpf_index] = rpf;
 
 	return 0;
diff --git a/include/media/vsp1.h b/include/media/vsp1.h
index cc1b0d42ce95..1ba7459b7a06 100644
--- a/include/media/vsp1.h
+++ b/include/media/vsp1.h
@@ -42,6 +42,18 @@ struct vsp1_du_lif_config {
 int vsp1_du_setup_lif(struct device *dev, unsigned int pipe_index,
 		      const struct vsp1_du_lif_config *cfg);
 
+/**
+ * enum vsp1_du_blend_mode - Pixel blend mode
+ * @VSP1_DU_BLEND_MODE_PREMULTI: Pixel alpha is pre-mutiplied
+ * @VSP1_DU_BLEND_MODE_COVERAGE: Pixel alpha is not pre-mutiplied
+ * @VSP1_DU_BLEND_MODE_PIXEL_NONE: Ignores the pixel alpha
+ */
+enum vsp1_du_blend_mode {
+	VSP1_DU_BLEND_MODE_PREMULTI,
+	VSP1_DU_BLEND_MODE_COVERAGE,
+	VSP1_DU_BLEND_MODE_PIXEL_NONE,
+};
+
 /**
  * struct vsp1_du_atomic_config - VSP atomic configuration parameters
  * @pixelformat: plane pixel format (V4L2 4CC)
@@ -51,6 +63,7 @@ int vsp1_du_setup_lif(struct device *dev, unsigned int pipe_index,
  * @dst: destination rectangle on the display (integer coordinates)
  * @alpha: alpha value (0: fully transparent, 255: fully opaque)
  * @zpos: Z position of the plane (from 0 to number of planes minus 1)
+ * @blend_mode: Pixel blend mode of the plane
  */
 struct vsp1_du_atomic_config {
 	u32 pixelformat;
@@ -60,6 +73,7 @@ struct vsp1_du_atomic_config {
 	struct v4l2_rect dst;
 	unsigned int alpha;
 	unsigned int zpos;
+	enum vsp1_du_blend_mode blend_mode;
 };
 
 /**
-- 
2.25.1

Re: [PATCH 2/3] media: vsp1: add blend mode support

[Laurent Pinchart]

Hi Hayama-san,

Thank you for the patch.

On Mon, Jul 04, 2022 at 11:52:30AM +0900, Takanari Hayama wrote:
> To support DRM blend mode in R-Car DU driver, we must add blend mode
> support in VSP1. Although VSP1 hardware is capable to support all blend
> mode defined in DRM, the current R-Car DU driver implicitly supports
> DRM_MODE_BLEND_COVERAGE only.
> 
> We add a new property to vsp1_du_atomic_config, so that R-Car DU driver
> can pass the desired blend mode.
> 
> Signed-off-by: Takanari Hayama <taki@igel.co.jp>
> ---
>  drivers/media/platform/renesas/vsp1/vsp1_drm.c | 11 +++++++++++
>  include/media/vsp1.h                           | 14 ++++++++++++++
>  2 files changed, 25 insertions(+)
> 
> diff --git a/drivers/media/platform/renesas/vsp1/vsp1_drm.c b/drivers/media/platform/renesas/vsp1/vsp1_drm.c
> index 9ec3ac835987..ed0cf552fce2 100644
> --- a/drivers/media/platform/renesas/vsp1/vsp1_drm.c
> +++ b/drivers/media/platform/renesas/vsp1/vsp1_drm.c
> @@ -861,6 +861,17 @@ int vsp1_du_atomic_update(struct device *dev, unsigned int pipe_index,
>  	vsp1->drm->inputs[rpf_index].compose = cfg->dst;
>  	vsp1->drm->inputs[rpf_index].zpos = cfg->zpos;
>  
> +	switch (cfg->blend_mode) {
> +	case VSP1_DU_BLEND_MODE_PREMULTI:
> +		rpf->format.flags = V4L2_PIX_FMT_FLAG_PREMUL_ALPHA;
> +		break;
> +	case VSP1_DU_BLEND_MODE_PIXEL_NONE:
> +		rpf->pixel_alpha = false;
> +		fallthrough;
> +	case VSP1_DU_BLEND_MODE_COVERAGE:
> +		rpf->format.flags = 0;
> +	}

This should work, but wouldn't it be simpler to override the format
passed in cfg->pixelformat in rcar_du_vsp_plane_setup() with the
non-alpha variant when state->state.pixel_blend_mode is set to
DRM_MODE_BLEND_PIXEL_NONE ? That way you could drop rpf->pixel_alpha,
turn cfg->blend_mode into a premult bool flag, and drop the
vsp1_du_blend_mode enum. There's only three formats with an alpha
channel that the rcar-du driver supports (DRM_FORMAT_ARGB4444,
DRM_FORMAT_ARGB1555 and DRM_FORMAT_ARGB8888), so the override could be
as simple as a switch (state->format->fourcc) when the blend mode is
NONE.

> +
>  	drm_pipe->pipe.inputs[rpf_index] = rpf;
>  
>  	return 0;
> diff --git a/include/media/vsp1.h b/include/media/vsp1.h
> index cc1b0d42ce95..1ba7459b7a06 100644
> --- a/include/media/vsp1.h
> +++ b/include/media/vsp1.h
> @@ -42,6 +42,18 @@ struct vsp1_du_lif_config {
>  int vsp1_du_setup_lif(struct device *dev, unsigned int pipe_index,
>  		      const struct vsp1_du_lif_config *cfg);
>  
> +/**
> + * enum vsp1_du_blend_mode - Pixel blend mode
> + * @VSP1_DU_BLEND_MODE_PREMULTI: Pixel alpha is pre-mutiplied
> + * @VSP1_DU_BLEND_MODE_COVERAGE: Pixel alpha is not pre-mutiplied
> + * @VSP1_DU_BLEND_MODE_PIXEL_NONE: Ignores the pixel alpha
> + */
> +enum vsp1_du_blend_mode {
> +	VSP1_DU_BLEND_MODE_PREMULTI,
> +	VSP1_DU_BLEND_MODE_COVERAGE,
> +	VSP1_DU_BLEND_MODE_PIXEL_NONE,
> +};
> +
>  /**
>   * struct vsp1_du_atomic_config - VSP atomic configuration parameters
>   * @pixelformat: plane pixel format (V4L2 4CC)
> @@ -51,6 +63,7 @@ int vsp1_du_setup_lif(struct device *dev, unsigned int pipe_index,
>   * @dst: destination rectangle on the display (integer coordinates)
>   * @alpha: alpha value (0: fully transparent, 255: fully opaque)
>   * @zpos: Z position of the plane (from 0 to number of planes minus 1)
> + * @blend_mode: Pixel blend mode of the plane
>   */
>  struct vsp1_du_atomic_config {
>  	u32 pixelformat;
> @@ -60,6 +73,7 @@ struct vsp1_du_atomic_config {
>  	struct v4l2_rect dst;
>  	unsigned int alpha;
>  	unsigned int zpos;
> +	enum vsp1_du_blend_mode blend_mode;
>  };
>  
>  /**

-- 
Regards,

Laurent Pinchart

Re: [PATCH 2/3] media: vsp1: add blend mode support

[Takanari Hayama]

Hi Laurent,

Thank you for reviewing the patch.

> 2022/07/31 7:36、Laurent Pinchart <laurent.pinchart@ideasonboard.com>のメール:
> 
> Hi Hayama-san,
> 
> Thank you for the patch.
> 
> On Mon, Jul 04, 2022 at 11:52:30AM +0900, Takanari Hayama wrote:
>> To support DRM blend mode in R-Car DU driver, we must add blend mode
>> support in VSP1. Although VSP1 hardware is capable to support all blend
>> mode defined in DRM, the current R-Car DU driver implicitly supports
>> DRM_MODE_BLEND_COVERAGE only.
>> 
>> We add a new property to vsp1_du_atomic_config, so that R-Car DU driver
>> can pass the desired blend mode.
>> 
>> Signed-off-by: Takanari Hayama <taki@igel.co.jp>
>> ---
>> drivers/media/platform/renesas/vsp1/vsp1_drm.c | 11 +++++++++++
>> include/media/vsp1.h | 14 ++++++++++++++
>> 2 files changed, 25 insertions(+)
>> 
>> diff --git a/drivers/media/platform/renesas/vsp1/vsp1_drm.c b/drivers/media/platform/renesas/vsp1/vsp1_drm.c
>> index 9ec3ac835987..ed0cf552fce2 100644
>> --- a/drivers/media/platform/renesas/vsp1/vsp1_drm.c
>> +++ b/drivers/media/platform/renesas/vsp1/vsp1_drm.c
>> @@ -861,6 +861,17 @@ int vsp1_du_atomic_update(struct device *dev, unsigned int pipe_index,
>> 	vsp1->drm->inputs[rpf_index].compose = cfg->dst;
>> 	vsp1->drm->inputs[rpf_index].zpos = cfg->zpos;
>> 
>> +	switch (cfg->blend_mode) {
>> +	case VSP1_DU_BLEND_MODE_PREMULTI:
>> +		rpf->format.flags = V4L2_PIX_FMT_FLAG_PREMUL_ALPHA;
>> +		break;
>> +	case VSP1_DU_BLEND_MODE_PIXEL_NONE:
>> +		rpf->pixel_alpha = false;
>> +		fallthrough;
>> +	case VSP1_DU_BLEND_MODE_COVERAGE:
>> +		rpf->format.flags = 0;
>> +	}
> 
> This should work, but wouldn't it be simpler to override the format
> passed in cfg->pixelformat in rcar_du_vsp_plane_setup() with the
> non-alpha variant when state->state.pixel_blend_mode is set to
> DRM_MODE_BLEND_PIXEL_NONE ? That way you could drop rpf->pixel_alpha,
> turn cfg->blend_mode into a premult bool flag, and drop the
> vsp1_du_blend_mode enum. There's only three formats with an alpha
> channel that the rcar-du driver supports (DRM_FORMAT_ARGB4444,
> DRM_FORMAT_ARGB1555 and DRM_FORMAT_ARGB8888), so the override could be
> as simple as a switch (state->format->fourcc) when the blend mode is
> NONE.

You’re right. I’ll make the suggested changes and submit V2.

> 
>> +
>> 	drm_pipe->pipe.inputs[rpf_index] = rpf;
>> 
>> 	return 0;
>> diff --git a/include/media/vsp1.h b/include/media/vsp1.h
>> index cc1b0d42ce95..1ba7459b7a06 100644
>> --- a/include/media/vsp1.h
>> +++ b/include/media/vsp1.h
>> @@ -42,6 +42,18 @@ struct vsp1_du_lif_config {
>> int vsp1_du_setup_lif(struct device *dev, unsigned int pipe_index,
>> 		 const struct vsp1_du_lif_config *cfg);
>> 
>> +/**
>> + * enum vsp1_du_blend_mode - Pixel blend mode
>> + * @VSP1_DU_BLEND_MODE_PREMULTI: Pixel alpha is pre-mutiplied
>> + * @VSP1_DU_BLEND_MODE_COVERAGE: Pixel alpha is not pre-mutiplied
>> + * @VSP1_DU_BLEND_MODE_PIXEL_NONE: Ignores the pixel alpha
>> + */
>> +enum vsp1_du_blend_mode {
>> +	VSP1_DU_BLEND_MODE_PREMULTI,
>> +	VSP1_DU_BLEND_MODE_COVERAGE,
>> +	VSP1_DU_BLEND_MODE_PIXEL_NONE,
>> +};
>> +
>> /**
>> * struct vsp1_du_atomic_config - VSP atomic configuration parameters
>> * @pixelformat: plane pixel format (V4L2 4CC)
>> @@ -51,6 +63,7 @@ int vsp1_du_setup_lif(struct device *dev, unsigned int pipe_index,
>> * @dst: destination rectangle on the display (integer coordinates)
>> * @alpha: alpha value (0: fully transparent, 255: fully opaque)
>> * @zpos: Z position of the plane (from 0 to number of planes minus 1)
>> + * @blend_mode: Pixel blend mode of the plane
>> */
>> struct vsp1_du_atomic_config {
>> 	u32 pixelformat;
>> @@ -60,6 +73,7 @@ struct vsp1_du_atomic_config {
>> 	struct v4l2_rect dst;
>> 	unsigned int alpha;
>> 	unsigned int zpos;
>> +	enum vsp1_du_blend_mode blend_mode;
>> };
>> 
>> /**
> 
> -- 
> Regards,
> 
> Laurent Pinchart

Cheers,
Takanari Hayama, Ph.D. <taki@igel.co.jp>
IGEL Co., Ltd.
https://www.igel.co.jp/

[PATCH 3/3] drm: rcar-du: Add DRM blend mode support

[Takanari Hayama]

R-Car DU supports different blend modes via VSP1. Add DRM blend mode
supports to make it configurable.

As drm_plane_create_blend_mode_property() creates the blend mode
property with the default value of DRM_MODE_BLEND_PREMULTI, it changes
the default blending behavior on R-Car DU. The rcar-du's blend mode was
same as DRM_MODE_BLEND_COVERAGE, i.e., pixel color values have not been
pre-multitplied.

Signed-off-by: Takanari Hayama <taki@igel.co.jp>
---
 drivers/gpu/drm/rcar-du/rcar_du_vsp.c | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

diff --git a/drivers/gpu/drm/rcar-du/rcar_du_vsp.c b/drivers/gpu/drm/rcar-du/rcar_du_vsp.c
index 8eb9b2b097ae..283327046aa5 100644
--- a/drivers/gpu/drm/rcar-du/rcar_du_vsp.c
+++ b/drivers/gpu/drm/rcar-du/rcar_du_vsp.c
@@ -170,6 +170,18 @@ static void rcar_du_vsp_plane_setup(struct rcar_du_vsp_plane *plane)
 	format = rcar_du_format_info(state->format->fourcc);
 	cfg.pixelformat = format->v4l2;
 
+	switch (state->state.pixel_blend_mode) {
+	case DRM_MODE_BLEND_PREMULTI:
+		cfg.blend_mode = VSP1_DU_BLEND_MODE_PREMULTI;
+		break;
+	case DRM_MODE_BLEND_COVERAGE:
+		cfg.blend_mode = VSP1_DU_BLEND_MODE_COVERAGE;
+		break;
+	case DRM_MODE_BLEND_PIXEL_NONE:
+		cfg.blend_mode = VSP1_DU_BLEND_MODE_PIXEL_NONE;
+		break;
+	}
+
 	vsp1_du_atomic_update(plane->vsp->vsp, crtc->vsp_pipe,
 			      plane->index, &cfg);
 }
@@ -444,6 +456,11 @@ int rcar_du_vsp_init(struct rcar_du_vsp *vsp, struct device_node *np,
 						       num_planes - 1);
 		}
 
+		drm_plane_create_blend_mode_property(&plane->plane,
+					BIT(DRM_MODE_BLEND_PIXEL_NONE) |
+					BIT(DRM_MODE_BLEND_PREMULTI) |
+					BIT(DRM_MODE_BLEND_COVERAGE));
+
 		vsp->num_planes++;
 	}
 
-- 
2.25.1

Re: [PATCH 3/3] drm: rcar-du: Add DRM blend mode support

[Laurent Pinchart]

Hi Hayama-san,

Thank you for the patch.

On Mon, Jul 04, 2022 at 11:52:31AM +0900, Takanari Hayama wrote:
> R-Car DU supports different blend modes via VSP1. Add DRM blend mode
> supports to make it configurable.
> 
> As drm_plane_create_blend_mode_property() creates the blend mode
> property with the default value of DRM_MODE_BLEND_PREMULTI, it changes
> the default blending behavior on R-Car DU. The rcar-du's blend mode was
> same as DRM_MODE_BLEND_COVERAGE, i.e., pixel color values have not been
> pre-multitplied.

If that's what KMS userspace requires I'm fine with it.

> Signed-off-by: Takanari Hayama <taki@igel.co.jp>

Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

but I expect this patch to change based on my suggestions for 2/3.

> ---
>  drivers/gpu/drm/rcar-du/rcar_du_vsp.c | 17 +++++++++++++++++
>  1 file changed, 17 insertions(+)
> 
> diff --git a/drivers/gpu/drm/rcar-du/rcar_du_vsp.c b/drivers/gpu/drm/rcar-du/rcar_du_vsp.c
> index 8eb9b2b097ae..283327046aa5 100644
> --- a/drivers/gpu/drm/rcar-du/rcar_du_vsp.c
> +++ b/drivers/gpu/drm/rcar-du/rcar_du_vsp.c
> @@ -170,6 +170,18 @@ static void rcar_du_vsp_plane_setup(struct rcar_du_vsp_plane *plane)
>  	format = rcar_du_format_info(state->format->fourcc);
>  	cfg.pixelformat = format->v4l2;
>  
> +	switch (state->state.pixel_blend_mode) {
> +	case DRM_MODE_BLEND_PREMULTI:
> +		cfg.blend_mode = VSP1_DU_BLEND_MODE_PREMULTI;
> +		break;
> +	case DRM_MODE_BLEND_COVERAGE:
> +		cfg.blend_mode = VSP1_DU_BLEND_MODE_COVERAGE;
> +		break;
> +	case DRM_MODE_BLEND_PIXEL_NONE:
> +		cfg.blend_mode = VSP1_DU_BLEND_MODE_PIXEL_NONE;
> +		break;
> +	}
> +
>  	vsp1_du_atomic_update(plane->vsp->vsp, crtc->vsp_pipe,
>  			      plane->index, &cfg);
>  }
> @@ -444,6 +456,11 @@ int rcar_du_vsp_init(struct rcar_du_vsp *vsp, struct device_node *np,
>  						       num_planes - 1);
>  		}
>  
> +		drm_plane_create_blend_mode_property(&plane->plane,
> +					BIT(DRM_MODE_BLEND_PIXEL_NONE) |
> +					BIT(DRM_MODE_BLEND_PREMULTI) |
> +					BIT(DRM_MODE_BLEND_COVERAGE));
> +
>  		vsp->num_planes++;
>  	}
>  

-- 
Regards,

Laurent Pinchart