diff mbox series

drm/stm: ltdc: add layer alpha support

Message ID 20210907151209.5716-1-raphael.gallais-pou@foss.st.com (mailing list archive)
State New, archived
Headers show
Series drm/stm: ltdc: add layer alpha support | expand

Commit Message

Raphael Gallais-Pou Sept. 7, 2021, 3:12 p.m. UTC 
Android Hardware Composer supports alpha values applied to layers.
Enabling non-opaque layers for the STM CRTC could help offload GPU
resources for screen composition.

Signed-off-by: Raphael Gallais-Pou <raphael.gallais-pou@foss.st.com>
---
 drivers/gpu/drm/stm/ltdc.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)
diff mbox series

Patch

diff --git a/drivers/gpu/drm/stm/ltdc.c b/drivers/gpu/drm/stm/ltdc.c
index 195de30eb90c..e0fef8bacfa8 100644
--- a/drivers/gpu/drm/stm/ltdc.c
+++ b/drivers/gpu/drm/stm/ltdc.c
@@ -845,7 +845,7 @@  static void ltdc_plane_atomic_update(struct drm_plane *plane,
 			LXCFBLR_CFBLL | LXCFBLR_CFBP, val);
 
 	/* Specifies the constant alpha value */
-	val = CONSTA_MAX;
+	val = newstate->alpha >> 8;
 	reg_update_bits(ldev->regs, LTDC_L1CACR + lofs, LXCACR_CONSTA, val);
 
 	/* Specifies the blending factors */
@@ -997,6 +997,8 @@  static struct drm_plane *ltdc_plane_create(struct drm_device *ddev,
 
 	drm_plane_helper_add(plane, &ltdc_plane_helper_funcs);
 
+	drm_plane_create_alpha_property(plane);
+
 	DRM_DEBUG_DRIVER("plane:%d created\n", plane->base.id);
 
 	return plane;