drm/vc4: plane: Add alpha_blend_mode property to each plane.

Move from only supporting the default of pre-multiplied
alpha to supporting user specified blend mode using the
standardised property.

Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.com>
Link: https://lore.kernel.org/r/20220613144800.326124-7-maxime@cerno.tech
Signed-off-by: Maxime Ripard <maxime@cerno.tech>

diff --git a/drivers/gpu/drm/vc4/vc4_plane.c b/drivers/gpu/drm/vc4/vc4_plane.c
index da850d0..5507f2c 100644 (file)
--- a/drivers/gpu/drm/vc4/vc4_plane.c
+++ b/drivers/gpu/drm/vc4/vc4_plane.c
@@ -666,6 +666,48 @@ static const u32 colorspace_coeffs[2][DRM_COLOR_ENCODING_MAX][3] = {
        }
 };
 
+static u32 vc4_hvs4_get_alpha_blend_mode(struct drm_plane_state *state)
+{
+       if (!state->fb->format->has_alpha)
+               return VC4_SET_FIELD(SCALER_POS2_ALPHA_MODE_FIXED,
+                                    SCALER_POS2_ALPHA_MODE);
+
+       switch (state->pixel_blend_mode) {
+       case DRM_MODE_BLEND_PIXEL_NONE:
+               return VC4_SET_FIELD(SCALER_POS2_ALPHA_MODE_FIXED,
+                                    SCALER_POS2_ALPHA_MODE);
+       default:
+       case DRM_MODE_BLEND_PREMULTI:
+               return VC4_SET_FIELD(SCALER_POS2_ALPHA_MODE_PIPELINE,
+                                    SCALER_POS2_ALPHA_MODE) |
+                       SCALER_POS2_ALPHA_PREMULT;
+       case DRM_MODE_BLEND_COVERAGE:
+               return VC4_SET_FIELD(SCALER_POS2_ALPHA_MODE_PIPELINE,
+                                    SCALER_POS2_ALPHA_MODE);
+       }
+}
+
+static u32 vc4_hvs5_get_alpha_blend_mode(struct drm_plane_state *state)
+{
+       if (!state->fb->format->has_alpha)
+               return VC4_SET_FIELD(SCALER5_CTL2_ALPHA_MODE_FIXED,
+                                    SCALER5_CTL2_ALPHA_MODE);
+
+       switch (state->pixel_blend_mode) {
+       case DRM_MODE_BLEND_PIXEL_NONE:
+               return VC4_SET_FIELD(SCALER5_CTL2_ALPHA_MODE_FIXED,
+                                    SCALER5_CTL2_ALPHA_MODE);
+       default:
+       case DRM_MODE_BLEND_PREMULTI:
+               return VC4_SET_FIELD(SCALER5_CTL2_ALPHA_MODE_PIPELINE,
+                                    SCALER5_CTL2_ALPHA_MODE) |
+                       SCALER5_CTL2_ALPHA_PREMULT;
+       case DRM_MODE_BLEND_COVERAGE:
+               return VC4_SET_FIELD(SCALER5_CTL2_ALPHA_MODE_PIPELINE,
+                                    SCALER5_CTL2_ALPHA_MODE);
+       }
+}
+
 /* Writes out a full display list for an active plane to the plane's
  * private dlist state.
  */
@@ -948,13 +990,8 @@ static int vc4_plane_mode_set(struct drm_plane *plane,
                /* Position Word 2: Source Image Size, Alpha */
                vc4_state->pos2_offset = vc4_state->dlist_count;
                vc4_dlist_write(vc4_state,
-                               VC4_SET_FIELD(fb->format->has_alpha ?
-                                             SCALER_POS2_ALPHA_MODE_PIPELINE :
-                                             SCALER_POS2_ALPHA_MODE_FIXED,
-                                             SCALER_POS2_ALPHA_MODE) |
                                (mix_plane_alpha ? SCALER_POS2_ALPHA_MIX : 0) |
-                               (fb->format->has_alpha ?
-                                               SCALER_POS2_ALPHA_PREMULT : 0) |
+                               vc4_hvs4_get_alpha_blend_mode(state) |
                                VC4_SET_FIELD(vc4_state->src_w[0],
                                              SCALER_POS2_WIDTH) |
                                VC4_SET_FIELD(vc4_state->src_h[0],
@@ -999,14 +1036,9 @@ static int vc4_plane_mode_set(struct drm_plane *plane,
                vc4_dlist_write(vc4_state,
                                VC4_SET_FIELD(state->alpha >> 4,
                                              SCALER5_CTL2_ALPHA) |
-                               (fb->format->has_alpha ?
-                                       SCALER5_CTL2_ALPHA_PREMULT : 0) |
+                               vc4_hvs5_get_alpha_blend_mode(state) |
                                (mix_plane_alpha ?
-                                       SCALER5_CTL2_ALPHA_MIX : 0) |
-                               VC4_SET_FIELD(fb->format->has_alpha ?
-                                     SCALER5_CTL2_ALPHA_MODE_PIPELINE :
-                                     SCALER5_CTL2_ALPHA_MODE_FIXED,
-                                     SCALER5_CTL2_ALPHA_MODE)
+                                       SCALER5_CTL2_ALPHA_MIX : 0)
                               );
 
                /* Position Word 1: Scaled Image Dimensions. */
@@ -1491,6 +1523,10 @@ struct drm_plane *vc4_plane_init(struct drm_device *dev,
        drm_plane_helper_add(plane, &vc4_plane_helper_funcs);
 
        drm_plane_create_alpha_property(plane);
+       drm_plane_create_blend_mode_property(plane,
+                                            BIT(DRM_MODE_BLEND_PIXEL_NONE) |
+                                            BIT(DRM_MODE_BLEND_PREMULTI) |
+                                            BIT(DRM_MODE_BLEND_COVERAGE));
        drm_plane_create_rotation_property(plane, DRM_MODE_ROTATE_0,
                                           DRM_MODE_ROTATE_0 |
                                           DRM_MODE_ROTATE_180 |