[PATCH v2] drm: mali-dp: Add CTM support

From: Mihail Atanassov
Date: Mon Feb 13 2017 - 07:49:48 EST


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@xxxxxxx>
---

Link to v1: https://lkml.org/lkml/2017/2/1/254

Changes since v1:
- Rebased and fixed conflicts
- Improved clarity of overflow check (+comment)
- Moved call to malidp_atomic_commit_update_coloradj in the existing crtc
for-each loop

This patch depends on "[PATCH v3 2/2] drm: mali-dp: enable gamma support", sent
out on 7 Feb (https://lkml.org/lkml/2017/2/7/547).

drivers/gpu/drm/arm/malidp_crtc.c | 58 +++++++++++++++++++++++++++++++++++++--
drivers/gpu/drm/arm/malidp_drv.c | 36 +++++++++++++++++++++++-
drivers/gpu/drm/arm/malidp_drv.h | 1 +
drivers/gpu/drm/arm/malidp_regs.h | 2 ++
4 files changed, 94 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/arm/malidp_crtc.c b/drivers/gpu/drm/arm/malidp_crtc.c
index 6a46520..7414540 100644
--- a/drivers/gpu/drm/arm/malidp_crtc.c
+++ b/drivers/gpu/drm/arm/malidp_crtc.c
@@ -192,6 +192,58 @@ 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)
{
@@ -269,6 +321,7 @@ static int malidp_crtc_atomic_check(struct drm_crtc *crtc,
}

ret = malidp_crtc_atomic_check_gamma(crtc, state);
+ ret = ret ? ret : malidp_crtc_atomic_check_ctm(crtc, state);

return ret;
}
@@ -288,6 +341,7 @@ 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, cs->gamma_coeffs, sizeof(state->gamma_coeffs));
+ memcpy(state->coloradj_coeffs, cs->coloradj_coeffs, sizeof(state->coloradj_coeffs));

return &state->base;
}
@@ -358,8 +412,8 @@ 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;

crtc_cleanup_planes:
diff --git a/drivers/gpu/drm/arm/malidp_drv.c b/drivers/gpu/drm/arm/malidp_drv.c
index ce741c3..15f0f91 100644
--- a/drivers/gpu/drm/arm/malidp_drv.c
+++ b/drivers/gpu/drm/arm/malidp_drv.c
@@ -77,6 +77,37 @@ 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
*/
@@ -139,10 +170,13 @@ 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_modeset_enables(drm, state);
+
drm_atomic_helper_commit_planes(drm, state, 0);

malidp_atomic_commit_hw_done(state);
diff --git a/drivers/gpu/drm/arm/malidp_drv.h b/drivers/gpu/drm/arm/malidp_drv.h
index fbf6187..3bd4c76 100644
--- a/drivers/gpu/drm/arm/malidp_drv.h
+++ b/drivers/gpu/drm/arm/malidp_drv.h
@@ -50,6 +50,7 @@ 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_regs.h b/drivers/gpu/drm/arm/malidp_regs.h
index eeba027..8c3f3ff 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 */
@@ -99,6 +100,7 @@

#define MALIDP_PRODUCT_ID(__core_id) ((u32)(__core_id) >> 16)

+#define MALIDP_COLORADJ_NUM_COEFFS 12
#define MALIDP_COEFFTAB_NUM_COEFFS 64
/* register offsets relative to MALIDP5x0_COEFFS_BASE */
#define MALIDP_COLOR_ADJ_COEF 0x00000
--
1.9.1