[PATCH 1/3] drm/vc4: Expose gamma as atomic property

[Stefan Schake]

We are an atomic driver so the gamma LUT should also be exposed as a
CRTC property through the DRM atomic color management. This will also
take care of the legacy path for us.

Signed-off-by: Stefan Schake <stschake at gmail.com>
---
 drivers/gpu/drm/vc4/vc4_crtc.c | 24 +++++++++++++-----------
 1 file changed, 13 insertions(+), 11 deletions(-)

diff --git a/drivers/gpu/drm/vc4/vc4_crtc.c b/drivers/gpu/drm/vc4/vc4_crtc.c
index bf46674..8d71098 100644
--- a/drivers/gpu/drm/vc4/vc4_crtc.c
+++ b/drivers/gpu/drm/vc4/vc4_crtc.c
@@ -298,23 +298,21 @@ vc4_crtc_lut_load(struct drm_crtc *crtc)
 		HVS_WRITE(SCALER_GAMDATA, vc4_crtc->lut_b[i]);
 }
 
-static int
-vc4_crtc_gamma_set(struct drm_crtc *crtc, u16 *r, u16 *g, u16 *b,
-		   uint32_t size,
-		   struct drm_modeset_acquire_ctx *ctx)
+static void
+vc4_crtc_update_gamma_lut(struct drm_crtc *crtc)
 {
 	struct vc4_crtc *vc4_crtc = to_vc4_crtc(crtc);
+	struct drm_color_lut *lut = crtc->state->gamma_lut->data;
+	u32 length = crtc->state->gamma_lut->length / sizeof(*lut);
 	u32 i;
 
-	for (i = 0; i < size; i++) {
-		vc4_crtc->lut_r[i] = r[i] >> 8;
-		vc4_crtc->lut_g[i] = g[i] >> 8;
-		vc4_crtc->lut_b[i] = b[i] >> 8;
+	for (i = 0; i < length; i++) {
+		vc4_crtc->lut_r[i] = drm_color_lut_extract(lut[i].red, 8);
+		vc4_crtc->lut_g[i] = drm_color_lut_extract(lut[i].green, 8);
+		vc4_crtc->lut_b[i] = drm_color_lut_extract(lut[i].blue, 8);
 	}
 
 	vc4_crtc_lut_load(crtc);
-
-	return 0;
 }
 
 static u32 vc4_get_fifo_full_level(u32 format)
@@ -699,6 +697,9 @@ static void vc4_crtc_atomic_flush(struct drm_crtc *crtc,
 	if (crtc->state->active && old_state->active)
 		vc4_crtc_update_dlist(crtc);
 
+	if (crtc->state->color_mgmt_changed && crtc->state->gamma_lut)
+		vc4_crtc_update_gamma_lut(crtc);
+
 	if (debug_dump_regs) {
 		DRM_INFO("CRTC %d HVS after:\n", drm_crtc_index(crtc));
 		vc4_hvs_dump_state(dev);
@@ -909,7 +910,7 @@ static const struct drm_crtc_funcs vc4_crtc_funcs = {
 	.reset = vc4_crtc_reset,
 	.atomic_duplicate_state = vc4_crtc_duplicate_state,
 	.atomic_destroy_state = vc4_crtc_destroy_state,
-	.gamma_set = vc4_crtc_gamma_set,
+	.gamma_set = drm_atomic_helper_legacy_gamma_set,
 	.enable_vblank = vc4_enable_vblank,
 	.disable_vblank = vc4_disable_vblank,
 };
@@ -1035,6 +1036,7 @@ static int vc4_crtc_bind(struct device *dev, struct device *master, void *data)
 	primary_plane->crtc = crtc;
 	vc4_crtc->channel = vc4_crtc->data->hvs_channel;
 	drm_mode_crtc_set_gamma_size(crtc, ARRAY_SIZE(vc4_crtc->lut_r));
+	drm_crtc_enable_color_mgmt(crtc, 0, false, crtc->gamma_size);
 
 	/* Set up some arbitrary number of planes.  We're not limited
 	 * by a set number of physical registers, just the space in
-- 
2.7.4