Commit ebae8d07 authored by Thierry Reding's avatar Thierry Reding
Browse files

drm/tegra: dc: Implement legacy blending 



This implements alpha blending on legacy display controllers (Tegra20,
Tegra30 and Tegra114). While it's theoretically possible to support the
zpos property to enable userspace to specify the Z-order of each plane
individually, this is not currently supported and the same fixed Z-
order as previously defined is used.

Reverts commit 71835caa ("drm/tegra: fb: Force alpha formats") since
the opaque formats are now supported.

Reported-by: default avatarDmitry Osipenko <digetx@gmail.com>
Fixes: 7772fdae ("drm/tegra: Support ARGB and ABGR formats")
Signed-off-by: default avatarThierry Reding <treding@nvidia.com>
parent 4c69ac12

drivers/gpu/drm/tegra/dc.c

+68 −13
Original line number Diff line number Diff line
@@ -154,30 +154,53 @@ static inline u32 compute_initial_dda(unsigned int in) 


static void tegra_plane_setup_blending_legacy(struct tegra_plane *plane)

{

	u32 background[3] = {

		BLEND_WEIGHT1(0) | BLEND_WEIGHT0(0) | BLEND_COLOR_KEY_NONE,

		BLEND_WEIGHT1(0) | BLEND_WEIGHT0(0) | BLEND_COLOR_KEY_NONE,

		BLEND_WEIGHT1(0) | BLEND_WEIGHT0(0) | BLEND_COLOR_KEY_NONE,

	};

	u32 foreground = BLEND_WEIGHT1(255) | BLEND_WEIGHT0(255) |

			 BLEND_COLOR_KEY_NONE;

	u32 blendnokey = BLEND_WEIGHT1(255) | BLEND_WEIGHT0(255);

	struct tegra_plane_state *state;

	unsigned int i;



	state = to_tegra_plane_state(plane->base.state);



	/* alpha contribution is 1 minus sum of overlapping windows */

	for (i = 0; i < 3; i++) {

		if (state->dependent[i])

			background[i] |= BLEND_CONTROL_DEPENDENT;

	}



	/* enable alpha blending if pixel format has an alpha component */

	if (!state->opaque)

		foreground |= BLEND_CONTROL_ALPHA;



	/*

	 * Disable blending and assume Window A is the bottom-most window,

	 * Window C is the top-most window and Window B is in the middle.

	 */

	tegra_plane_writel(plane, 0xffff00, DC_WIN_BLEND_NOKEY);

	tegra_plane_writel(plane, 0xffff00, DC_WIN_BLEND_1WIN);

	tegra_plane_writel(plane, blendnokey, DC_WIN_BLEND_NOKEY);

	tegra_plane_writel(plane, foreground, DC_WIN_BLEND_1WIN);



	switch (plane->index) {

	case 0:

		tegra_plane_writel(plane, 0x000000, DC_WIN_BLEND_2WIN_X);

		tegra_plane_writel(plane, 0x000000, DC_WIN_BLEND_2WIN_Y);

		tegra_plane_writel(plane, 0x000000, DC_WIN_BLEND_3WIN_XY);

		tegra_plane_writel(plane, background[0], DC_WIN_BLEND_2WIN_X);

		tegra_plane_writel(plane, background[1], DC_WIN_BLEND_2WIN_Y);

		tegra_plane_writel(plane, background[2], DC_WIN_BLEND_3WIN_XY);

		break;



	case 1:

		tegra_plane_writel(plane, 0xffff00, DC_WIN_BLEND_2WIN_X);

		tegra_plane_writel(plane, 0x000000, DC_WIN_BLEND_2WIN_Y);

		tegra_plane_writel(plane, 0x000000, DC_WIN_BLEND_3WIN_XY);

		tegra_plane_writel(plane, foreground, DC_WIN_BLEND_2WIN_X);

		tegra_plane_writel(plane, background[1], DC_WIN_BLEND_2WIN_Y);

		tegra_plane_writel(plane, background[2], DC_WIN_BLEND_3WIN_XY);

		break;



	case 2:

		tegra_plane_writel(plane, 0xffff00, DC_WIN_BLEND_2WIN_X);

		tegra_plane_writel(plane, 0xffff00, DC_WIN_BLEND_2WIN_Y);

		tegra_plane_writel(plane, 0xffff00, DC_WIN_BLEND_3WIN_XY);

		tegra_plane_writel(plane, foreground, DC_WIN_BLEND_2WIN_X);

		tegra_plane_writel(plane, foreground, DC_WIN_BLEND_2WIN_Y);

		tegra_plane_writel(plane, foreground, DC_WIN_BLEND_3WIN_XY);

		break;

	}

}
@@ -353,6 +376,11 @@ static const u32 tegra20_primary_formats[] = { 
	DRM_FORMAT_RGBA5551,

	DRM_FORMAT_ABGR8888,

	DRM_FORMAT_ARGB8888,

	/* non-native formats */

	DRM_FORMAT_XRGB1555,

	DRM_FORMAT_RGBX5551,

	DRM_FORMAT_XBGR8888,

	DRM_FORMAT_XRGB8888,

};



static const u32 tegra114_primary_formats[] = {
@@ -409,18 +437,40 @@ static int tegra_plane_atomic_check(struct drm_plane *plane, 
	struct tegra_bo_tiling *tiling = &plane_state->tiling;

	struct tegra_plane *tegra = to_tegra_plane(plane);

	struct tegra_dc *dc = to_tegra_dc(state->crtc);

	unsigned int format;

	int err;



	/* no need for further checks if the plane is being disabled */

	if (!state->crtc)

		return 0;



	err = tegra_plane_format(state->fb->format->format,

				 &plane_state->format,

	err = tegra_plane_format(state->fb->format->format, &format,

				 &plane_state->swap);

	if (err < 0)

		return err;



	/*

	 * Tegra20 and Tegra30 are special cases here because they support

	 * only variants of specific formats with an alpha component, but not

	 * the corresponding opaque formats. However, the opaque formats can

	 * be emulated by disabling alpha blending for the plane.

	 */

	if (!dc->soc->supports_blending) {

		if (!tegra_plane_format_has_alpha(format)) {

			err = tegra_plane_format_get_alpha(format, &format);

			if (err < 0)

				return err;



			plane_state->opaque = true;

		} else {

			plane_state->opaque = false;

		}



		tegra_plane_check_dependent(tegra, plane_state);

	}



	plane_state->format = format;



	err = tegra_fb_get_tiling(state->fb, tiling);

	if (err < 0)

		return err;
@@ -737,6 +787,11 @@ static const u32 tegra20_overlay_formats[] = { 
	DRM_FORMAT_RGBA5551,

	DRM_FORMAT_ABGR8888,

	DRM_FORMAT_ARGB8888,

	/* non-native formats */

	DRM_FORMAT_XRGB1555,

	DRM_FORMAT_RGBX5551,

	DRM_FORMAT_XBGR8888,

	DRM_FORMAT_XRGB8888,

	/* planar formats */

	DRM_FORMAT_UYVY,

	DRM_FORMAT_YUYV,

drivers/gpu/drm/tegra/dc.h

+12 −0
Original line number Diff line number Diff line
@@ -649,8 +649,20 @@ int tegra_dc_rgb_exit(struct tegra_dc *dc); 
#define DC_WIN_DV_CONTROL			0x70e



#define DC_WIN_BLEND_NOKEY			0x70f

#define  BLEND_WEIGHT1(x) (((x) & 0xff) << 16)

#define  BLEND_WEIGHT0(x) (((x) & 0xff) <<  8)



#define DC_WIN_BLEND_1WIN			0x710

#define  BLEND_CONTROL_FIX    (0 << 2)

#define  BLEND_CONTROL_ALPHA  (1 << 2)

#define  BLEND_COLOR_KEY_NONE (0 << 0)

#define  BLEND_COLOR_KEY_0    (1 << 0)

#define  BLEND_COLOR_KEY_1    (2 << 0)

#define  BLEND_COLOR_KEY_BOTH (3 << 0)



#define DC_WIN_BLEND_2WIN_X			0x711

#define  BLEND_CONTROL_DEPENDENT (2 << 2)



#define DC_WIN_BLEND_2WIN_Y			0x712

#define DC_WIN_BLEND_3WIN_XY			0x713

drivers/gpu/drm/tegra/fb.c

+0 −12
Original line number Diff line number Diff line
@@ -254,18 +254,6 @@ static int tegra_fbdev_probe(struct drm_fb_helper *helper, 
	cmd.pitches[0] = round_up(sizes->surface_width * bytes_per_pixel,

				  tegra->pitch_align);



	/*

	 * Early generations of Tegra (Tegra20 and Tegra30) do not support any

	 * of the X* or *X formats, only their A* or *A equivalents. Force the

	 * legacy framebuffer format to include an alpha component so that the

	 * framebuffer emulation can be supported on all generations.

	 */

	if (sizes->surface_bpp == 32 && sizes->surface_depth == 24)

		sizes->surface_depth = 32;



	if (sizes->surface_bpp == 16 && sizes->surface_depth == 15)

		sizes->surface_depth = 16;



	cmd.pixel_format = drm_mode_legacy_fb_format(sizes->surface_bpp,

						     sizes->surface_depth);

drivers/gpu/drm/tegra/plane.c

+138 −0
Original line number Diff line number Diff line
@@ -43,6 +43,7 @@ tegra_plane_atomic_duplicate_state(struct drm_plane *plane) 
{

	struct tegra_plane_state *state = to_tegra_plane_state(plane->state);

	struct tegra_plane_state *copy;

	unsigned int i;



	copy = kmalloc(sizeof(*copy), GFP_KERNEL);

	if (!copy)
@@ -52,6 +53,10 @@ tegra_plane_atomic_duplicate_state(struct drm_plane *plane) 
	copy->tiling = state->tiling;

	copy->format = state->format;

	copy->swap = state->swap;

	copy->opaque = state->opaque;



	for (i = 0; i < 3; i++)

		copy->dependent[i] = state->dependent[i];



	return &copy->base;

}
@@ -238,3 +243,136 @@ bool tegra_plane_format_is_yuv(unsigned int format, bool *planar) 


	return false;

}



static bool __drm_format_has_alpha(u32 format)

{

	switch (format) {

	case DRM_FORMAT_ARGB1555:

	case DRM_FORMAT_RGBA5551:

	case DRM_FORMAT_ABGR8888:

	case DRM_FORMAT_ARGB8888:

		return true;

	}



	return false;

}



/*

 * This is applicable to Tegra20 and Tegra30 only where the opaque formats can

 * be emulated using the alpha formats and alpha blending disabled.

 */

bool tegra_plane_format_has_alpha(unsigned int format)

{

	switch (format) {

	case WIN_COLOR_DEPTH_B5G5R5A1:

	case WIN_COLOR_DEPTH_A1B5G5R5:

	case WIN_COLOR_DEPTH_R8G8B8A8:

	case WIN_COLOR_DEPTH_B8G8R8A8:

		return true;

	}



	return false;

}



int tegra_plane_format_get_alpha(unsigned int opaque, unsigned int *alpha)

{

	switch (opaque) {

	case WIN_COLOR_DEPTH_B5G5R5X1:

		*alpha = WIN_COLOR_DEPTH_B5G5R5A1;

		return 0;



	case WIN_COLOR_DEPTH_X1B5G5R5:

		*alpha = WIN_COLOR_DEPTH_A1B5G5R5;

		return 0;



	case WIN_COLOR_DEPTH_R8G8B8X8:

		*alpha = WIN_COLOR_DEPTH_R8G8B8A8;

		return 0;



	case WIN_COLOR_DEPTH_B8G8R8X8:

		*alpha = WIN_COLOR_DEPTH_B8G8R8A8;

		return 0;

	}



	return -EINVAL;

}



unsigned int tegra_plane_get_overlap_index(struct tegra_plane *plane,

					   struct tegra_plane *other)

{

	unsigned int index = 0, i;



	WARN_ON(plane == other);



	for (i = 0; i < 3; i++) {

		if (i == plane->index)

			continue;



		if (i == other->index)

			break;



		index++;

	}



	return index;

}



void tegra_plane_check_dependent(struct tegra_plane *tegra,

				 struct tegra_plane_state *state)

{

	struct drm_plane_state *old, *new;

	struct drm_plane *plane;

	unsigned int zpos[2];

	unsigned int i;



	for (i = 0; i < 3; i++)

		state->dependent[i] = false;



	for (i = 0; i < 2; i++)

		zpos[i] = 0;



	for_each_oldnew_plane_in_state(state->base.state, plane, old, new, i) {

		struct tegra_plane *p = to_tegra_plane(plane);

		unsigned index;



		/* skip this plane and planes on different CRTCs */

		if (p == tegra || new->crtc != state->base.crtc)

			continue;



		index = tegra_plane_get_overlap_index(tegra, p);



		/*

		 * If any of the other planes is on top of this plane and uses

		 * a format with an alpha component, mark this plane as being

		 * dependent, meaning it's alpha value will be 1 minus the sum

		 * of alpha components of the overlapping planes.

		 */

		if (p->index > tegra->index) {

			if (__drm_format_has_alpha(new->fb->format->format))

				state->dependent[index] = true;



			/* keep track of the Z position */

			zpos[index] = p->index;

		}

	}



	/*

	 * The region where three windows overlap is the intersection of the

	 * two regions where two windows overlap. It contributes to the area

	 * if any of the windows on top of it have an alpha component.

	 */

	for (i = 0; i < 2; i++)

		state->dependent[2] = state->dependent[2] ||

				      state->dependent[i];



	/*

	 * However, if any of the windows on top of this window is opaque, it

	 * will completely conceal this window within that area, so avoid the

	 * window from contributing to the area.

	 */

	for (i = 0; i < 2; i++) {

		if (zpos[i] > tegra->index)

			state->dependent[2] = state->dependent[2] &&

					      state->dependent[i];

	}

}

drivers/gpu/drm/tegra/plane.h

+8 −0
Original line number Diff line number Diff line
@@ -40,6 +40,10 @@ struct tegra_plane_state { 
	struct tegra_bo_tiling tiling;

	u32 format;

	u32 swap;



	/* used for legacy blending support only */

	bool opaque;

	bool dependent[3];

};



static inline struct tegra_plane_state *
@@ -58,5 +62,9 @@ int tegra_plane_state_add(struct tegra_plane *plane, 


int tegra_plane_format(u32 fourcc, u32 *format, u32 *swap);

bool tegra_plane_format_is_yuv(unsigned int format, bool *planar);

bool tegra_plane_format_has_alpha(unsigned int format);

int tegra_plane_format_get_alpha(unsigned int opaque, unsigned int *alpha);

void tegra_plane_check_dependent(struct tegra_plane *tegra,

				 struct tegra_plane_state *state);



#endif /* TEGRA_PLANE_H */