Re: [PATCH v2 2/3] drm/mediatek: Add gamma lut support for mt8195

From: AngeloGioacchino Del Regno
Date: Tue Aug 30 2022 - 03:47:42 EST

Il 30/08/22 08:39, zheng-yan.chen ha scritto:
Since the previous gamma_set_common() function is designed for
9bit-to-10bit conversion, which is not feasible for the
10bit-to-12bit conversion in mt8195.

Update the function to fit the need of mt8195.

Fixes: 7266e90a51a3 ("drm/mediatek: Add mediatek-drm of vdosys0 support for mt8195")
Signed-off-by: zheng-yan.chen <zheng-yan.chen@xxxxxxxxxxxx>
---
drivers/gpu/drm/mediatek/mtk_disp_aal.c | 2 +-
drivers/gpu/drm/mediatek/mtk_disp_drv.h | 3 +-
drivers/gpu/drm/mediatek/mtk_disp_gamma.c | 102 +++++++++++++++-----
drivers/gpu/drm/mediatek/mtk_drm_crtc.c | 5 +-
drivers/gpu/drm/mediatek/mtk_drm_crtc.h | 1 -
drivers/gpu/drm/mediatek/mtk_drm_ddp_comp.c | 1 +
drivers/gpu/drm/mediatek/mtk_drm_ddp_comp.h | 1 +
drivers/gpu/drm/mediatek/mtk_drm_drv.c | 2 +
8 files changed, 85 insertions(+), 32 deletions(-)

diff --git a/drivers/gpu/drm/mediatek/mtk_disp_aal.c b/drivers/gpu/drm/mediatek/mtk_disp_aal.c
index 0f9d7efb61d7..f563eee3c330 100644
--- a/drivers/gpu/drm/mediatek/mtk_disp_aal.c
+++ b/drivers/gpu/drm/mediatek/mtk_disp_aal.c
@@ -66,7 +66,7 @@ void mtk_aal_gamma_set(struct device *dev, struct drm_crtc_state *state)
struct mtk_disp_aal *aal = dev_get_drvdata(dev);
if (aal->data && aal->data->has_gamma)
- mtk_gamma_set_common(aal->regs, state, false);
+ mtk_gamma_set_common(aal->regs, state, dev);
}
void mtk_aal_start(struct device *dev)
diff --git a/drivers/gpu/drm/mediatek/mtk_disp_drv.h b/drivers/gpu/drm/mediatek/mtk_disp_drv.h
index 33e61a136bbc..c1269fce9a66 100644
--- a/drivers/gpu/drm/mediatek/mtk_disp_drv.h
+++ b/drivers/gpu/drm/mediatek/mtk_disp_drv.h
@@ -51,8 +51,9 @@ void mtk_gamma_clk_disable(struct device *dev);
void mtk_gamma_config(struct device *dev, unsigned int w,
unsigned int h, unsigned int vrefresh,
unsigned int bpc, struct cmdq_pkt *cmdq_pkt);
+unsigned int mtk_gamma_size(struct device *dev);
void mtk_gamma_set(struct device *dev, struct drm_crtc_state *state);
-void mtk_gamma_set_common(void __iomem *regs, struct drm_crtc_state *state, bool lut_diff);
+void mtk_gamma_set_common(void __iomem *regs, struct drm_crtc_state *state, struct device *dev);
void mtk_gamma_start(struct device *dev);
void mtk_gamma_stop(struct device *dev);
diff --git a/drivers/gpu/drm/mediatek/mtk_disp_gamma.c b/drivers/gpu/drm/mediatek/mtk_disp_gamma.c
index bbd558a036ec..0409e15fceb3 100644
--- a/drivers/gpu/drm/mediatek/mtk_disp_gamma.c
+++ b/drivers/gpu/drm/mediatek/mtk_disp_gamma.c
@@ -18,18 +18,22 @@
#define DISP_GAMMA_EN 0x0000
#define GAMMA_EN BIT(0)
#define DISP_GAMMA_CFG 0x0020
+#define RELAY_MODE BIT(0)
#define GAMMA_LUT_EN BIT(1)
#define GAMMA_DITHERING BIT(2)
#define DISP_GAMMA_SIZE 0x0030
+#define DISP_GAMMA_BANK 0x0100
#define DISP_GAMMA_LUT 0x0700
-
-#define LUT_10BIT_MASK 0x03ff
-
+#define DISP_GAMMA_LUT1 0x0b00

+#define TABLE_9BIT_SIZE 512
+#define TABLE_10BIT_SIZE 1024

Please remove these two unused definitions.

+#define BANK_SIZE 256
struct mtk_disp_gamma_data {
bool has_dither;
bool lut_diff;
+ unsigned int lut_size;
+ unsigned int lut_bits;

We can reduce the size of this structure by using

u16 lut_size;
u8 lut_bits;

};
-
/*
* struct mtk_disp_gamma - DISP_GAMMA driver structure
*/
@@ -54,40 +58,75 @@ void mtk_gamma_clk_disable(struct device *dev)
clk_disable_unprepare(gamma->clk);
}
-void mtk_gamma_set_common(void __iomem *regs, struct drm_crtc_state *state, bool lut_diff)
+void mtk_gamma_set_common(void __iomem *regs, struct drm_crtc_state *state, struct device *dev)
{
- unsigned int i, reg;
- struct drm_color_lut *lut;
+ unsigned int i, reg, idx;
void __iomem *lut_base;
- u32 word;
- u32 diff[3] = {0};
+ void __iomem *lut1_base;
+ u32 word, word1;
+ struct mtk_disp_gamma *gamma = dev_get_drvdata(dev);

Please reorder these definitions, (columns) longest first, shortest last

if (state->gamma_lut) {
+ u32 table_size;
+ u32 mask;
+ u32 lut_bits;
+ u32 shift_bits;
+ bool lut_diff;
+ struct drm_color_lut color, color_rec;
+ struct drm_color_lut *lut = (struct drm_color_lut *)state->gamma_lut;


struct drm_color_lut *lut = (struct drm_color_lut *)state->gamma_lut;
struct drm_color_lut color, color_rec;
u32 lut_bits, shift_bits;
u32 mask, table_size;
bool lut_diff;

+
+ table_size = gamma->data->lut_size;
+ lut_bits = gamma->data->lut_bits;
+ lut_diff = gamma->data->lut_diff;
+ shift_bits = (lut_bits == 12) ? 4 : 6;
+ mask = GENMASK(lut_bits - 1, 0);
reg = readl(regs + DISP_GAMMA_CFG);
+ reg = reg & ~RELAY_MODE;
reg = reg | GAMMA_LUT_EN;
writel(reg, regs + DISP_GAMMA_CFG);
lut_base = regs + DISP_GAMMA_LUT;
- lut = (struct drm_color_lut *)state->gamma_lut->data;
- for (i = 0; i < MTK_LUT_SIZE; i++) {
-
- if (!lut_diff || (i % 2 == 0)) {
- word = (((lut[i].red >> 6) & LUT_10BIT_MASK) << 20) +
- (((lut[i].green >> 6) & LUT_10BIT_MASK) << 10) +
- ((lut[i].blue >> 6) & LUT_10BIT_MASK);
+ lut1_base = regs + DISP_GAMMA_LUT1;
+ for (i = 0; i < table_size; i++) {
+ color.red = (lut[i].red >> shift_bits) & mask;
+ color.green = (lut[i].green >> shift_bits) & mask;
+ color.blue = (lut[i].blue >> shift_bits) & mask;
+ if (lut_diff && (i % 2)) {
+ word = (lut_bits == 12) ?
+ (((color.green - color_rec.green) << 12) +
+ (color.red - color_rec.red))
+ :
+ (((color.red - color_rec.red) << 20) +
+ ((color.green - color_rec.green) << 10) +
+ (color.blue - color_rec.blue));
+ word1 = (color.blue - color_rec.blue);
} else {
- diff[0] = (lut[i].red >> 6) - (lut[i - 1].red >> 6);
- diff[1] = (lut[i].green >> 6) - (lut[i - 1].green >> 6);
- diff[2] = (lut[i].blue >> 6) - (lut[i - 1].blue >> 6);
-
- word = ((diff[0] & LUT_10BIT_MASK) << 20) +
- ((diff[1] & LUT_10BIT_MASK) << 10) +
- (diff[2] & LUT_10BIT_MASK);
+ word = (lut_bits == 12) ?
+ ((color.green << 12) + color.red)
+ :
+ ((color.red << 20) +
+ (color.green << 10) + color.blue);
+ word1 = color.blue;
+ color_rec = color;
}
- writel(word, (lut_base + i * 4));
+ idx = (lut_bits == 12) ? (i % BANK_SIZE) : i;
+ writel(word, (lut_base + idx * 4));
+ if (!(i % BANK_SIZE) && lut_bits == 12)
+ writel((i / BANK_SIZE), regs + DISP_GAMMA_BANK);
+ if (lut_bits == 12)
+ writel(word1, (lut1_base + idx * 4));
}
}
}
+unsigned int mtk_gamma_size(struct device *dev)

unsigned int mtk_gamma_get_lut_size(struct device *dev)

that looks a bit more readable and perfectly explains this function :-)

+{
+ struct mtk_disp_gamma *gamma = dev_get_drvdata(dev);
+
+ if (gamma->data)
+ return gamma->data->lut_size;
+ else
+ return 0;
+}
void mtk_gamma_set(struct device *dev, struct drm_crtc_state *state)
{
struct mtk_disp_gamma *gamma = dev_get_drvdata(dev);

..snip..

diff --git a/drivers/gpu/drm/mediatek/mtk_drm_ddp_comp.c b/drivers/gpu/drm/mediatek/mtk_drm_ddp_comp.c
index 2d72cc5ddaba..4c6538a17b88 100644
--- a/drivers/gpu/drm/mediatek/mtk_drm_ddp_comp.c
+++ b/drivers/gpu/drm/mediatek/mtk_drm_ddp_comp.c
@@ -323,6 +323,7 @@ static const struct mtk_ddp_comp_funcs ddp_gamma = {
.clk_enable = mtk_gamma_clk_enable,
.clk_disable = mtk_gamma_clk_disable,
.gamma_set = mtk_gamma_set,
+ .gamma_size = mtk_gamma_size,
.config = mtk_gamma_config,
.start = mtk_gamma_start,
.stop = mtk_gamma_stop,
diff --git a/drivers/gpu/drm/mediatek/mtk_drm_ddp_comp.h b/drivers/gpu/drm/mediatek/mtk_drm_ddp_comp.h
index 2d0052c23dcb..bf0cf7f86010 100644
--- a/drivers/gpu/drm/mediatek/mtk_drm_ddp_comp.h
+++ b/drivers/gpu/drm/mediatek/mtk_drm_ddp_comp.h
@@ -59,6 +59,7 @@ struct mtk_ddp_comp_funcs {
void (*disable_vblank)(struct device *dev);
unsigned int (*supported_rotations)(struct device *dev);
unsigned int (*layer_nr)(struct device *dev);
+ unsigned int (*gamma_size)(struct device *dev);

unsigned int (*gamma_get_lut_size)(struct device *dev);

int (*layer_check)(struct device *dev,
unsigned int idx,
struct mtk_plane_state *state);

Regards,
Angelo