drm: mali-dp: Add CTM support

All DPs have a COLORADJ matrix which is applied prior to output gamma.
Attach that to the CTM property. Also, ensure the input CTM's coefficients
can fit in the DP registers' Q3.12 format.

Signed-off-by: Mihail Atanassov <mihail.atanassov@arm.com>
Signed-off-by: Liviu Dudau <Liviu.Dudau@arm.com>

5 files changed, 98 insertions, 4 deletions

diff --git a/drivers/gpu/drm/arm/malidp_crtc.c b/drivers/gpu/drm/arm/malidp_crtc.c
index 27ab09459b9d..8f2e1ae51ba0 100644
--- a/drivers/gpu/drm/arm/malidp_crtc.c
+++ b/drivers/gpu/drm/arm/malidp_crtc.c
@@ -195,6 +195,58 @@ static int malidp_crtc_atomic_check_gamma(struct drm_crtc *crtc,
         return 0;
 }
 
+/*
+ * Check if there is a new CTM and if it contains valid input. Valid here means
+ * that the number is inside the representable range for a Q3.12 number,
+ * excluding truncating the fractional part of the input data.
+ *
+ * The COLORADJ registers can be changed atomically.
+ */
+static int malidp_crtc_atomic_check_ctm(struct drm_crtc *crtc,
+                                        struct drm_crtc_state *state)
+{
+        struct malidp_crtc_state *mc = to_malidp_crtc_state(state);
+        struct drm_color_ctm *ctm;
+        int i;
+
+        if (!state->color_mgmt_changed)
+                return 0;
+
+        if (!state->ctm)
+                return 0;
+
+        if (crtc->state->ctm && (crtc->state->ctm->base.id ==
+                                 state->ctm->base.id))
+                return 0;
+
+        /*
+         * The size of the ctm is checked in
+         * drm_atomic_replace_property_blob_from_id.
+         */
+        ctm = (struct drm_color_ctm *)state->ctm->data;
+        for (i = 0; i < ARRAY_SIZE(ctm->matrix); ++i) {
+                /* Convert from S31.32 to Q3.12. */
+                s64 val = ctm->matrix[i];
+                u32 mag = ((((u64)val) & ~BIT_ULL(63)) >> 20) &
+                          GENMASK_ULL(14, 0);
+
+                /*
+                 * Convert to 2s complement and check the destination's top bit
+                 * for overflow. NB: Can't check before converting or it'd
+                 * incorrectly reject the case:
+                 * sign == 1
+                 * mag == 0x2000
+                 */
+                if (val & BIT_ULL(63))
+                        mag = ~mag + 1;
+                if (!!(val & BIT_ULL(63)) != !!(mag & BIT(14)))
+                        return -EINVAL;
+                mc->coloradj_coeffs[i] = mag;
+        }
+
+        return 0;
+}
+
 static int malidp_crtc_atomic_check(struct drm_crtc *crtc,
                                     struct drm_crtc_state *state)
 {
@@ -204,6 +256,7 @@ static int malidp_crtc_atomic_check(struct drm_crtc *crtc,
         const struct drm_plane_state *pstate;
         u32 rot_mem_free, rot_mem_usable;
         int rotated_planes = 0;
+        int ret;
 
         /*
          * check if there is enough rotation memory available for planes
@@ -270,7 +323,10 @@ static int malidp_crtc_atomic_check(struct drm_crtc *crtc,
                 }
         }
 
-        return malidp_crtc_atomic_check_gamma(crtc, state);
+        ret = malidp_crtc_atomic_check_gamma(crtc, state);
+        ret = ret ? ret : malidp_crtc_atomic_check_ctm(crtc, state);
+
+        return ret;
 }
 
 static const struct drm_crtc_helper_funcs malidp_crtc_helper_funcs = {
@@ -295,6 +351,8 @@ static struct drm_crtc_state *malidp_crtc_duplicate_state(struct drm_crtc *crtc)
         __drm_atomic_helper_crtc_duplicate_state(crtc, &state->base);
         memcpy(state->gamma_coeffs, old_state->gamma_coeffs,
                sizeof(state->gamma_coeffs));
+        memcpy(state->coloradj_coeffs, old_state->coloradj_coeffs,
+               sizeof(state->coloradj_coeffs));
 
         return &state->base;
 }
@@ -392,8 +450,8 @@ int malidp_crtc_init(struct drm_device *drm)
 
         drm_crtc_helper_add(&malidp->crtc, &malidp_crtc_helper_funcs);
         drm_mode_crtc_set_gamma_size(&malidp->crtc, MALIDP_GAMMA_LUT_SIZE);
-        /* No inverse-gamma and color adjustments yet. */
-        drm_crtc_enable_color_mgmt(&malidp->crtc, 0, false, MALIDP_GAMMA_LUT_SIZE);
+        /* No inverse-gamma: it is per-plane */
+        drm_crtc_enable_color_mgmt(&malidp->crtc, 0, true, MALIDP_GAMMA_LUT_SIZE);
 
         return 0;
 
diff --git a/drivers/gpu/drm/arm/malidp_drv.c b/drivers/gpu/drm/arm/malidp_drv.c
index 1eb6bbc5118a..eae41e26b819 100644
--- a/drivers/gpu/drm/arm/malidp_drv.c
+++ b/drivers/gpu/drm/arm/malidp_drv.c
@@ -79,6 +79,37 @@ static void malidp_atomic_commit_update_gamma(struct drm_crtc *crtc,
         }
 }
 
+static
+void malidp_atomic_commit_update_coloradj(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;
+        int i;
+
+        if (!crtc->state->color_mgmt_changed)
+                return;
+
+        if (!crtc->state->ctm) {
+                malidp_hw_clearbits(hwdev, MALIDP_DISP_FUNC_CADJ,
+                                    MALIDP_DE_DISPLAY_FUNC);
+        } else {
+                struct malidp_crtc_state *mc =
+                        to_malidp_crtc_state(crtc->state);
+
+                if (!old_state->ctm || (crtc->state->ctm->base.id !=
+                                        old_state->ctm->base.id))
+                        for (i = 0; i < MALIDP_COLORADJ_NUM_COEFFS; ++i)
+                                malidp_hw_write(hwdev,
+                                                mc->coloradj_coeffs[i],
+                                                hwdev->map.coeffs_base +
+                                                MALIDP_COLOR_ADJ_COEF + 4 * i);
+
+                malidp_hw_setbits(hwdev, MALIDP_DISP_FUNC_CADJ,
+                                  MALIDP_DE_DISPLAY_FUNC);
+        }
+}
+
 /*
  * set the "config valid" bit and wait until the hardware acts on it
  */
@@ -145,8 +176,10 @@ static void malidp_atomic_commit_tail(struct drm_atomic_state *state)
 
         drm_atomic_helper_commit_modeset_disables(drm, state);
 
-        for_each_crtc_in_state(state, crtc, old_crtc_state, i)
+        for_each_crtc_in_state(state, crtc, old_crtc_state, i) {
                 malidp_atomic_commit_update_gamma(crtc, old_crtc_state);
+                malidp_atomic_commit_update_coloradj(crtc, old_crtc_state);
+        }
 
         drm_atomic_helper_commit_planes(drm, state, 0);
 
diff --git a/drivers/gpu/drm/arm/malidp_drv.h b/drivers/gpu/drm/arm/malidp_drv.h
index f5abd8bfbd2b..e1c784dcdd92 100644
--- a/drivers/gpu/drm/arm/malidp_drv.h
+++ b/drivers/gpu/drm/arm/malidp_drv.h
@@ -51,6 +51,7 @@ struct malidp_plane_state {
 struct malidp_crtc_state {
         struct drm_crtc_state base;
         u32 gamma_coeffs[MALIDP_COEFFTAB_NUM_COEFFS];
+        u32 coloradj_coeffs[MALIDP_COLORADJ_NUM_COEFFS];
 };
 
 #define to_malidp_crtc_state(x) container_of(x, struct malidp_crtc_state, base)
diff --git a/drivers/gpu/drm/arm/malidp_hw.h b/drivers/gpu/drm/arm/malidp_hw.h
index c2df6b6e7645..470fe71724a3 100644
--- a/drivers/gpu/drm/arm/malidp_hw.h
+++ b/drivers/gpu/drm/arm/malidp_hw.h
@@ -259,6 +259,7 @@ static inline bool malidp_hw_pitch_valid(struct malidp_hw_device *hwdev,
 #define MALIDP_BGND_COLOR_G             0x000
 #define MALIDP_BGND_COLOR_B             0x000
 
+#define MALIDP_COLORADJ_NUM_COEFFS      12
 #define MALIDP_COEFFTAB_NUM_COEFFS      64
 
 #define MALIDP_GAMMA_LUT_SIZE           4096
diff --git a/drivers/gpu/drm/arm/malidp_regs.h b/drivers/gpu/drm/arm/malidp_regs.h
index 28252c5b31b5..4bf338d4172e 100644
--- a/drivers/gpu/drm/arm/malidp_regs.h
+++ b/drivers/gpu/drm/arm/malidp_regs.h
@@ -64,6 +64,7 @@
 /* bit masks that are common between products */
 #define   MALIDP_CFG_VALID              (1 << 0)
 #define   MALIDP_DISP_FUNC_GAMMA        (1 << 0)
+#define   MALIDP_DISP_FUNC_CADJ         (1 << 4)
 #define   MALIDP_DISP_FUNC_ILACED       (1 << 8)
 
 /* register offsets for IRQ management */