[PATCH v3 1/2] drm/mediatek: Add gamma correction

Bibby Hsieh
2016-07-07T07:37:24Z

Apply gamma function to correct brightness values.
It applies arbitrary mapping curve to compensate the
incorrect transfer function of the panel.

Signed-off-by: Bibby Hsieh <bibby.hsieh@mediatek.com>
---
drivers/gpu/drm/mediatek/mtk_drm_crtc.c | 8 +++
drivers/gpu/drm/mediatek/mtk_drm_crtc.h | 1 +
drivers/gpu/drm/mediatek/mtk_drm_ddp_comp.c | 89 ++++++++++++++++++++++++++-
drivers/gpu/drm/mediatek/mtk_drm_ddp_comp.h | 10 +++
4 files changed, 106 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/mediatek/mtk_drm_crtc.c b/drivers/gpu/drm/mediatek/mtk_drm_crtc.c
index 24aa3ba..ee219bb 100644
--- a/drivers/gpu/drm/mediatek/mtk_drm_crtc.c
+++ b/drivers/gpu/drm/mediatek/mtk_drm_crtc.c
@@ -409,6 +409,10 @@ static void mtk_drm_crtc_atomic_flush(struct drm_crtc *crtc,
}
if (pending_planes)
mtk_crtc->pending_planes = true;
+ if (crtc->state->color_mgmt_changed)
+ for (i = 0; i < mtk_crtc->ddp_comp_nr; i++)
+ mtk_ddp_gamma_set(mtk_crtc->ddp_comp[i], crtc->state);
+
}

static const struct drm_crtc_funcs mtk_crtc_funcs = {
@@ -418,6 +422,7 @@ static const struct drm_crtc_funcs mtk_crtc_funcs = {
.reset = mtk_drm_crtc_reset,
.atomic_duplicate_state = mtk_drm_crtc_duplicate_state,
.atomic_destroy_state = mtk_drm_crtc_destroy_state,
+ .gamma_set = drm_atomic_helper_legacy_gamma_set,
};

static const struct drm_crtc_helper_funcs mtk_crtc_helper_funcs = {
@@ -569,6 +574,9 @@ int mtk_drm_crtc_create(struct drm_device *drm_dev,
if (ret < 0)
goto unprepare;

+ drm_mode_crtc_set_gamma_size(&mtk_crtc->base, MTK_LUT_SIZE);
+ drm_helper_crtc_enable_color_mgmt(&mtk_crtc->base, MTK_LUT_SIZE,
+ MTK_LUT_SIZE);
priv->crtc[pipe] = &mtk_crtc->base;
priv->num_pipes++;

diff --git a/drivers/gpu/drm/mediatek/mtk_drm_crtc.h b/drivers/gpu/drm/mediatek/mtk_drm_crtc.h
index 81e5566..d332564 100644
--- a/drivers/gpu/drm/mediatek/mtk_drm_crtc.h
+++ b/drivers/gpu/drm/mediatek/mtk_drm_crtc.h
@@ -19,6 +19,7 @@
#include "mtk_drm_plane.h"

#define OVL_LAYER_NR 4
+#define MTK_LUT_SIZE 512

int mtk_drm_crtc_enable_vblank(struct drm_device *drm, unsigned int pipe);
void mtk_drm_crtc_disable_vblank(struct drm_device *drm, unsigned int pipe);
diff --git a/drivers/gpu/drm/mediatek/mtk_drm_ddp_comp.c b/drivers/gpu/drm/mediatek/mtk_drm_ddp_comp.c
index 3970fcf..56c5894 100644
--- a/drivers/gpu/drm/mediatek/mtk_drm_ddp_comp.c
+++ b/drivers/gpu/drm/mediatek/mtk_drm_ddp_comp.c
@@ -24,6 +24,7 @@
#include "mtk_drm_drv.h"
#include "mtk_drm_plane.h"
#include "mtk_drm_ddp_comp.h"
+#include "mtk_drm_crtc.h"

#define DISP_OD_EN 0x0000
#define DISP_OD_INTEN 0x0008
@@ -38,6 +39,21 @@
#define DISP_COLOR_WIDTH 0x0c50
#define DISP_COLOR_HEIGHT 0x0c54

+#define DISP_AAL_EN 0x000
+#define DISP_AAL_SIZE 0x030
+
+#define DISP_GAMMA_EN 0x000
+#define DISP_GAMMA_CFG 0x020
+#define DISP_GAMMA_SIZE 0x030
+#define DISP_GAMMA_LUT 0x700
+
+#define LUT_10BIT_MASK 0x3ff
+
+#define AAL_EN BIT(0)
+
+#define GAMMA_EN BIT(0)
+#define GAMMA_LUT_EN BIT(1)
+
#define OD_RELAY_MODE BIT(0)

#define UFO_BYPASS BIT(2)
@@ -76,6 +92,61 @@ static void mtk_ufoe_start(struct mtk_ddp_comp *comp)
writel(UFO_BYPASS, comp->regs + DISP_REG_UFO_START);
}

+static void mtk_aal_config(struct mtk_ddp_comp *comp, unsigned int w,
+ unsigned int h, unsigned int vrefresh)
+{
+ writel(h << 16 | w, comp->regs + DISP_AAL_SIZE);
+}
+
+static void mtk_aal_start(struct mtk_ddp_comp *comp)
+{
+ writel(AAL_EN, comp->regs + DISP_AAL_EN);
+}
+
+static void mtk_aal_stop(struct mtk_ddp_comp *comp)
+{
+ writel_relaxed(0x0, comp->regs + DISP_AAL_EN);
+}
+
+static void mtk_gamma_config(struct mtk_ddp_comp *comp, unsigned int w,
+ unsigned int h, unsigned int vrefresh)
+{
+ writel(h << 16 | w, comp->regs + DISP_GAMMA_SIZE);
+}
+
+static void mtk_gamma_start(struct mtk_ddp_comp *comp)
+{
+ writel(GAMMA_EN, comp->regs + DISP_GAMMA_EN);
+}
+
+static void mtk_gamma_stop(struct mtk_ddp_comp *comp)
+{
+ writel_relaxed(0x0, comp->regs + DISP_GAMMA_EN);
+}
+
+static void mtk_gamma_set(struct mtk_ddp_comp *comp,
+ struct drm_crtc_state *state)
+{
+ unsigned int i, reg;
+ struct drm_color_lut *lut;
+ void __iomem *lut_base;
+ u32 word;
+
+ if (state->gamma_lut) {
+ reg = readl(comp->regs + DISP_GAMMA_CFG);
+ reg = reg | GAMMA_LUT_EN;
+ writel(reg, comp->regs + DISP_GAMMA_CFG);
+ lut_base = comp->regs + DISP_GAMMA_LUT;
+ lut = (struct drm_color_lut *)state->gamma_lut->data;
+ for (i = 0; i < MTK_LUT_SIZE; i++) {
+ word = (((lut[i].red >> 6) & LUT_10BIT_MASK) << 20) +
+ (((lut[i].green >> 6) & LUT_10BIT_MASK) << 10) +
+ ((lut[i].blue >> 6) & LUT_10BIT_MASK);
+ writel(word, (lut_base + i * 4));
+ }
+ }
+}
+
static const struct mtk_ddp_comp_funcs ddp_color = {
.config = mtk_color_config,
.start = mtk_color_start,
@@ -90,6 +161,20 @@ static const struct mtk_ddp_comp_funcs ddp_ufoe = {
.start = mtk_ufoe_start,
};

+static const struct mtk_ddp_comp_funcs ddp_aal = {
+ .gamma_set = mtk_gamma_set,
+ .config = mtk_aal_config,
+ .start = mtk_aal_start,
+ .stop = mtk_aal_stop,
+};
+
+static const struct mtk_ddp_comp_funcs ddp_gamma = {
+ .gamma_set = mtk_gamma_set,
+ .config = mtk_gamma_config,
+ .start = mtk_gamma_start,
+ .stop = mtk_gamma_stop,
+};
+
static const char * const mtk_ddp_comp_stem[MTK_DDP_COMP_TYPE_MAX] = {
[MTK_DISP_OVL] = "ovl",
[MTK_DISP_RDMA] = "rdma",
@@ -112,13 +197,13 @@ struct mtk_ddp_comp_match {
};

static const struct mtk_ddp_comp_match mtk_ddp_matches[DDP_COMPONENT_ID_MAX] = {
- [DDP_COMPONENT_AAL] = { MTK_DISP_AAL, 0, NULL },
+ [DDP_COMPONENT_AAL] = { MTK_DISP_AAL, 0, &ddp_aal },
[DDP_COMPONENT_COLOR0] = { MTK_DISP_COLOR, 0, &ddp_color },
[DDP_COMPONENT_COLOR1] = { MTK_DISP_COLOR, 1, &ddp_color },
[DDP_COMPONENT_DPI0] = { MTK_DPI, 0, NULL },
[DDP_COMPONENT_DSI0] = { MTK_DSI, 0, NULL },
[DDP_COMPONENT_DSI1] = { MTK_DSI, 1, NULL },
- [DDP_COMPONENT_GAMMA] = { MTK_DISP_GAMMA, 0, NULL },
+ [DDP_COMPONENT_GAMMA] = { MTK_DISP_GAMMA, 0, &ddp_gamma },
[DDP_COMPONENT_OD] = { MTK_DISP_OD, 0, &ddp_od },
[DDP_COMPONENT_OVL0] = { MTK_DISP_OVL, 0, NULL },
[DDP_COMPONENT_OVL1] = { MTK_DISP_OVL, 1, NULL },
diff --git a/drivers/gpu/drm/mediatek/mtk_drm_ddp_comp.h b/drivers/gpu/drm/mediatek/mtk_drm_ddp_comp.h
index 6b13ba9..07e17fe 100644
--- a/drivers/gpu/drm/mediatek/mtk_drm_ddp_comp.h
+++ b/drivers/gpu/drm/mediatek/mtk_drm_ddp_comp.h
@@ -20,6 +20,7 @@ struct device;
struct device_node;
struct drm_crtc;
struct drm_device;
+struct drm_crtc_state;
struct mtk_plane_state;

enum mtk_ddp_comp_type {
@@ -73,6 +74,8 @@ struct mtk_ddp_comp_funcs {
void (*layer_off)(struct mtk_ddp_comp *comp, unsigned int idx);
void (*layer_config)(struct mtk_ddp_comp *comp, unsigned int idx,
struct mtk_plane_state *state);
+ void (*gamma_set)(struct mtk_ddp_comp *comp,
+ struct drm_crtc_state *state);
};

struct mtk_ddp_comp {
@@ -139,6 +142,13 @@ static inline void mtk_ddp_comp_layer_config(struct mtk_ddp_comp *comp,
comp->funcs->layer_config(comp, idx, state);
}

+static inline void mtk_ddp_gamma_set(struct mtk_ddp_comp *comp,
+ struct drm_crtc_state *state)
+{
+ if (comp->funcs && comp->funcs->gamma_set)
+ comp->funcs->gamma_set(comp, state);
+}
+
int mtk_ddp_comp_get_id(struct device_node *node,
enum mtk_ddp_comp_type comp_type);
int mtk_ddp_comp_init(struct device *dev, struct device_node *comp_node,
--
1.7.9.5