The hardware supports a CTM with S0.9 values. We therefore only allow
a value of 1.0 or fractional only and reject all others with integer
parts. This restriction is mostly inconsequential in practice since
commonly used transformation matrices have all scalars <= 1.0.
Signed-off-by: Stefan Schake <stschake@xxxxxxxxx>
---
v2: Simplify CTM atomic check (Ville)
drivers/gpu/drm/vc4/vc4_crtc.c | 97 ++++++++++++++++++++++++++++++++++++++++--
1 file changed, 94 insertions(+), 3 deletions(-)
diff --git a/drivers/gpu/drm/vc4/vc4_crtc.c b/drivers/gpu/drm/vc4/vc4_crtc.c
index 8d71098d00c4..bafb0102fe1d 100644
--- a/drivers/gpu/drm/vc4/vc4_crtc.c
+++ b/drivers/gpu/drm/vc4/vc4_crtc.c
@@ -315,6 +315,79 @@ vc4_crtc_update_gamma_lut(struct drm_crtc *crtc)
vc4_crtc_lut_load(crtc);
}
+/* Converts a DRM S31.32 value to the HW S0.9 format. */
+static u16 vc4_crtc_s31_32_to_s0_9(u64 in)
+{
+ u16 r;
+
+ /* Sign bit. */
+ r = in & BIT_ULL(63) ? BIT(9) : 0;
+ /* We have zero integer bits so we can only saturate here. */
+ if ((in & GENMASK_ULL(62, 32)) > 0)
+ r |= GENMASK(8, 0);
+ /* Otherwise take the 9 most important fractional bits. */
+ else
+ r |= (in >> 22) & GENMASK(8, 0);
+ return r;
+}
+
+static void
+vc4_crtc_update_ctm(struct drm_crtc *crtc)
+{
+ struct drm_device *dev = crtc->dev;
+ struct vc4_dev *vc4 = to_vc4_dev(dev);
+ struct vc4_crtc *vc4_crtc = to_vc4_crtc(crtc);
+ struct drm_color_ctm *ctm = crtc->state->ctm->data;
+
+ HVS_WRITE(SCALER_OLEDCOEF2,
+ VC4_SET_FIELD(vc4_crtc_s31_32_to_s0_9(ctm->matrix[0]),
+ SCALER_OLEDCOEF2_R_TO_R) |
+ VC4_SET_FIELD(vc4_crtc_s31_32_to_s0_9(ctm->matrix[3]),
+ SCALER_OLEDCOEF2_R_TO_G) |
+ VC4_SET_FIELD(vc4_crtc_s31_32_to_s0_9(ctm->matrix[6]),
+ SCALER_OLEDCOEF2_R_TO_B));
+ HVS_WRITE(SCALER_OLEDCOEF1,
+ VC4_SET_FIELD(vc4_crtc_s31_32_to_s0_9(ctm->matrix[1]),
+ SCALER_OLEDCOEF1_G_TO_R) |
+ VC4_SET_FIELD(vc4_crtc_s31_32_to_s0_9(ctm->matrix[4]),
+ SCALER_OLEDCOEF1_G_TO_G) |
+ VC4_SET_FIELD(vc4_crtc_s31_32_to_s0_9(ctm->matrix[7]),
+ SCALER_OLEDCOEF1_G_TO_B));
+ HVS_WRITE(SCALER_OLEDCOEF0,
+ VC4_SET_FIELD(vc4_crtc_s31_32_to_s0_9(ctm->matrix[2]),
+ SCALER_OLEDCOEF0_B_TO_R) |
+ VC4_SET_FIELD(vc4_crtc_s31_32_to_s0_9(ctm->matrix[5]),
+ SCALER_OLEDCOEF0_B_TO_G) |
+ VC4_SET_FIELD(vc4_crtc_s31_32_to_s0_9(ctm->matrix[8]),
+ SCALER_OLEDCOEF0_B_TO_B));
+
+ /* Channel is 0-based but for DISPFIFO, 0 means disabled. */
+ HVS_WRITE(SCALER_OLEDOFFS, VC4_SET_FIELD(vc4_crtc->channel + 1,
+ SCALER_OLEDOFFS_DISPFIFO));
+}
+
+/* Check if the CTM contains valid input.
+ *
+ * DRM exposes CTM with S31.32 scalars, but the HW only supports S0.9.
+ * We don't allow integer values >1, and 1 only without fractional part
+ * to handle the common 1.0 value.
+ */
+static int vc4_crtc_atomic_check_ctm(struct drm_crtc_state *state)
+{
+ struct drm_color_ctm *ctm = state->ctm->data;
+ u32 i;
+
+ for (i = 0; i < ARRAY_SIZE(ctm->matrix); i++) {
+ u64 val = ctm->matrix[i];
+
+ val &= ~BIT_ULL(63);
+ if (val > BIT_ULL(32))
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
static u32 vc4_get_fifo_full_level(u32 format)
{
static const u32 fifo_len_bytes = 64;
@@ -621,6 +694,15 @@ static int vc4_crtc_atomic_check(struct drm_crtc *crtc,
if (hweight32(state->connector_mask) > 1)
return -EINVAL;
+ if (state->ctm) {
+ /* The CTM hardware has no integer bits, so we check
+ * and reject scalars >1.0 that we have no chance of
+ * approximating.
+ */
+ if (vc4_crtc_atomic_check_ctm(state))
+ return -EINVAL;
+ }
+
drm_atomic_crtc_state_for_each_plane_state(plane, plane_state, state)
dlist_count += vc4_plane_dlist_size(plane_state);
@@ -697,8 +779,17 @@ 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 (crtc->state->color_mgmt_changed) {
+ if (crtc->state->gamma_lut)
+ vc4_crtc_update_gamma_lut(crtc);
+
+ if (crtc->state->ctm)
+ vc4_crtc_update_ctm(crtc);
+ /* We are transitioning to CTM disabled. */
+ else if (old_state->ctm)
+ HVS_WRITE(SCALER_OLEDOFFS,
+ VC4_SET_FIELD(0, SCALER_OLEDOFFS_DISPFIFO));
+ }
if (debug_dump_regs) {
DRM_INFO("CRTC %d HVS after:\n", drm_crtc_index(crtc));
@@ -1036,7 +1127,7 @@ 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);
+ drm_crtc_enable_color_mgmt(crtc, 0, true, 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
--
2.14.1
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