drm: mali-dp: enable gamma support
Add gamma via the DRM GAMMA_LUT/GAMMA_LUT_SIZE CRTC
properties. The expected LUT size is 4096 in order
to produce as accurate a set of segments as possible.
This version uses only the green channel's gamma curve
to set the hardware curve on DP550/650. For the sake of
simplicity, it uses the same table of coefficients for
all 3 curves on DP500.
Signed-off-by: Mihail Atanassov <mihail.atanassov@arm.com>
Signed-off-by: Liviu Dudau <liviu.dudau@arm.com>
diff --git a/drivers/gpu/drm/arm/malidp_drv.c b/drivers/gpu/drm/arm/malidp_drv.c
index e954c22..1eb6bbc 100644
--- a/drivers/gpu/drm/arm/malidp_drv.c
+++ b/drivers/gpu/drm/arm/malidp_drv.c
@@ -34,6 +34,51 @@
#define MALIDP_CONF_VALID_TIMEOUT 250
+static void malidp_write_gamma_table(struct malidp_hw_device *hwdev,
+ u32 data[MALIDP_COEFFTAB_NUM_COEFFS])
+{
+ int i;
+ /* Update all channels with a single gamma curve. */
+ const u32 gamma_write_mask = GENMASK(18, 16);
+ /*
+ * Always write an entire table, so the address field in
+ * DE_COEFFTAB_ADDR is 0 and we can use the gamma_write_mask bitmask
+ * directly.
+ */
+ malidp_hw_write(hwdev, gamma_write_mask,
+ hwdev->map.coeffs_base + MALIDP_COEF_TABLE_ADDR);
+ for (i = 0; i < MALIDP_COEFFTAB_NUM_COEFFS; ++i)
+ malidp_hw_write(hwdev, data[i],
+ hwdev->map.coeffs_base +
+ MALIDP_COEF_TABLE_DATA);
+}
+
+static void malidp_atomic_commit_update_gamma(struct drm_crtc *crtc,
+ struct drm_crtc_state *old_state)
+{
+ struct malidp_drm *malidp = crtc_to_malidp_device(crtc);
+ struct malidp_hw_device *hwdev = malidp->dev;
+
+ if (!crtc->state->color_mgmt_changed)
+ return;
+
+ if (!crtc->state->gamma_lut) {
+ malidp_hw_clearbits(hwdev,
+ MALIDP_DISP_FUNC_GAMMA,
+ MALIDP_DE_DISPLAY_FUNC);
+ } else {
+ struct malidp_crtc_state *mc =
+ to_malidp_crtc_state(crtc->state);
+
+ if (!old_state->gamma_lut || (crtc->state->gamma_lut->base.id !=
+ old_state->gamma_lut->base.id))
+ malidp_write_gamma_table(hwdev, mc->gamma_coeffs);
+
+ malidp_hw_setbits(hwdev, MALIDP_DISP_FUNC_GAMMA,
+ MALIDP_DE_DISPLAY_FUNC);
+ }
+}
+
/*
* set the "config valid" bit and wait until the hardware acts on it
*/
@@ -92,11 +137,17 @@ static void malidp_atomic_commit_hw_done(struct drm_atomic_state *state)
static void malidp_atomic_commit_tail(struct drm_atomic_state *state)
{
struct drm_device *drm = state->dev;
+ struct drm_crtc *crtc;
+ struct drm_crtc_state *old_crtc_state;
+ int i;
pm_runtime_get_sync(drm->dev);
drm_atomic_helper_commit_modeset_disables(drm, state);
+ for_each_crtc_in_state(state, crtc, old_crtc_state, i)
+ malidp_atomic_commit_update_gamma(crtc, old_crtc_state);
+
drm_atomic_helper_commit_planes(drm, state, 0);
drm_atomic_helper_commit_modeset_enables(drm, state);