All of lore.kernel.org
 help / color / mirror / Atom feed
* [PATCH v2] drm/stm: ltdc: add layer alpha support
@ 2021-09-07 15:15 ` Raphael Gallais-Pou
  0 siblings, 0 replies; 4+ messages in thread
From: Raphael Gallais-Pou @ 2021-09-07 15:15 UTC (permalink / raw)
  To: Yannick Fertre, Philippe Cornu, Benjamin Gaignard
  Cc: David Airlie, Daniel Vetter, Maxime Coquelin, Alexandre Torgue,
	dri-devel, linux-stm32, linux-arm-kernel, linux-kernel,
	Raphael Gallais-Pou, Raphael Gallais-Pou

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>
Acked-by: Yannick Fertre <yannick.fertre@foss.st.com>
Reviewed-by: Yannick Fertre <yannick.fertre@foss.st.com>
---
 drivers/gpu/drm/stm/ltdc.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

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;
-- 
2.17.1


^ permalink raw reply related	[flat|nested] 4+ messages in thread

end of thread, other threads:[~2021-09-09 13:41 UTC | newest]

Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2021-09-07 15:15 [PATCH v2] drm/stm: ltdc: add layer alpha support Raphael Gallais-Pou
2021-09-07 15:15 ` Raphael Gallais-Pou
2021-09-09 13:08 ` Philippe CORNU
2021-09-09 13:08   ` Philippe CORNU

This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.