drm/vkms: add 3x4 matrix in color pipeline

We add two 3x4 matrices into the VKMS color pipeline. The reason
we're adding matrices is so that we can test that application
of a matrix and its inverse yields an output equal to the input
image.

One complication with the matrix implementation has to do with
the fact that the matrix entries are in signed-magnitude fixed
point, whereas the drm_fixed.h implementation uses 2s-complement.
The latter one is the one that we want for easy addition and
subtraction, so we convert all entries to 2s-complement.

Reviewed-by: Louis Chauvet <louis.chauvet@bootlin.com>
Signed-off-by: Alex Hung <alex.hung@amd.com>
Signed-off-by: Harry Wentland <harry.wentland@amd.com>
Reviewed-by: Daniel Stone <daniels@collabora.com>
Signed-off-by: Simon Ser <contact@emersion.fr>
Link: https://patch.msgid.link/20251115000237.3561250-21-alex.hung@amd.com

diff --git a/drivers/gpu/drm/vkms/vkms_colorop.c b/drivers/gpu/drm/vkms/vkms_colorop.c
index 946e9641d940e611d37d84c9781379a5354ad90c..7aceb0813b2d7f7919d1dcb09049267f64584283 100644 (file)
--- a/drivers/gpu/drm/vkms/vkms_colorop.c
+++ b/drivers/gpu/drm/vkms/vkms_colorop.c
@@ -12,7 +12,7 @@ static const u64 supported_tfs =
        BIT(DRM_COLOROP_1D_CURVE_SRGB_EOTF) |
        BIT(DRM_COLOROP_1D_CURVE_SRGB_INV_EOTF);
 
-#define MAX_COLOR_PIPELINE_OPS 2
+#define MAX_COLOR_PIPELINE_OPS 4
 
 static int vkms_initialize_color_pipeline(struct drm_plane *plane, struct drm_prop_enum_list *list)
 {
@@ -40,7 +40,39 @@ static int vkms_initialize_color_pipeline(struct drm_plane *plane, struct drm_pr
 
        i++;
 
-       /* 2nd op: 1d curve */
+       /* 2nd op: 3x4 matrix */
+       ops[i] = kzalloc(sizeof(*ops[i]), GFP_KERNEL);
+       if (!ops[i]) {
+               drm_err(dev, "KMS: Failed to allocate colorop\n");
+               ret = -ENOMEM;
+               goto cleanup;
+       }
+
+       ret = drm_plane_colorop_ctm_3x4_init(dev, ops[i], plane);
+       if (ret)
+               goto cleanup;
+
+       drm_colorop_set_next_property(ops[i - 1], ops[i]);
+
+       i++;
+
+       /* 3rd op: 3x4 matrix */
+       ops[i] = kzalloc(sizeof(*ops[i]), GFP_KERNEL);
+       if (!ops[i]) {
+               drm_err(dev, "KMS: Failed to allocate colorop\n");
+               ret = -ENOMEM;
+               goto cleanup;
+       }
+
+       ret = drm_plane_colorop_ctm_3x4_init(dev, ops[i], plane);
+       if (ret)
+               goto cleanup;
+
+       drm_colorop_set_next_property(ops[i - 1], ops[i]);
+
+       i++;
+
+       /* 4th op: 1d curve */
        ops[i] = kzalloc(sizeof(*ops[i]), GFP_KERNEL);
        if (!ops[i]) {
                drm_err(dev, "KMS: Failed to allocate colorop\n");

diff --git a/drivers/gpu/drm/vkms/vkms_composer.c b/drivers/gpu/drm/vkms/vkms_composer.c
index 3c1ec430f509602826bb5b835ed76749e0d362b0..214f82da3b0bf3183111bc449f2ce80f7ee4055e 100644 (file)
--- a/drivers/gpu/drm/vkms/vkms_composer.c
+++ b/drivers/gpu/drm/vkms/vkms_composer.c
@@ -128,6 +128,35 @@ static void apply_lut(const struct vkms_crtc_state *crtc_state, struct line_buff
        }
 }
 
+static void apply_3x4_matrix(struct pixel_argb_s32 *pixel, const struct drm_color_ctm_3x4 *matrix)
+{
+       s64 rf, gf, bf;
+       s64 r, g, b;
+
+       r = drm_int2fixp(pixel->r);
+       g = drm_int2fixp(pixel->g);
+       b = drm_int2fixp(pixel->b);
+
+       rf = drm_fixp_mul(drm_sm2fixp(matrix->matrix[0]), r) +
+            drm_fixp_mul(drm_sm2fixp(matrix->matrix[1]), g) +
+            drm_fixp_mul(drm_sm2fixp(matrix->matrix[2]), b) +
+            drm_sm2fixp(matrix->matrix[3]);
+
+       gf = drm_fixp_mul(drm_sm2fixp(matrix->matrix[4]), r) +
+            drm_fixp_mul(drm_sm2fixp(matrix->matrix[5]), g) +
+            drm_fixp_mul(drm_sm2fixp(matrix->matrix[6]), b) +
+            drm_sm2fixp(matrix->matrix[7]);
+
+       bf = drm_fixp_mul(drm_sm2fixp(matrix->matrix[8]), r) +
+            drm_fixp_mul(drm_sm2fixp(matrix->matrix[9]), g) +
+            drm_fixp_mul(drm_sm2fixp(matrix->matrix[10]), b) +
+            drm_sm2fixp(matrix->matrix[11]);
+
+       pixel->r = drm_fixp2int_round(rf);
+       pixel->g = drm_fixp2int_round(gf);
+       pixel->b = drm_fixp2int_round(bf);
+}
+
 static void apply_colorop(struct pixel_argb_s32 *pixel, struct drm_colorop *colorop)
 {
        struct drm_colorop_state *colorop_state = colorop->state;
@@ -151,6 +180,10 @@ static void apply_colorop(struct pixel_argb_s32 *pixel, struct drm_colorop *colo
                                      colorop_state->curve_1d_type);
                        break;
                }
+       } else if (colorop->type == DRM_COLOROP_CTM_3X4) {
+               if (colorop_state->data)
+                       apply_3x4_matrix(pixel,
+                                        (struct drm_color_ctm_3x4 *)colorop_state->data->data);
        }
 }