[PATCH RESEND v6 09/11] drm/mediatek: gamma: Add support for 12-bit LUT and MT8195

AngeloGioacchino Del Regno
2023-07-27T09:48:15Z

Add support for 12-bit gamma lookup tables and introduce the first
user for it: MT8195.
While at it, also reorder the variables in mtk_gamma_set_common()
and rename `lut_base` to `lut0_base` to improve readability.

Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Reviewed-by: Jason-JH.Lin <jason-jh.lin@mediatek.com>
---
drivers/gpu/drm/mediatek/mtk_disp_gamma.c | 61 ++++++++++++++++++-----
1 file changed, 48 insertions(+), 13 deletions(-)

diff --git a/drivers/gpu/drm/mediatek/mtk_disp_gamma.c b/drivers/gpu/drm/mediatek/mtk_disp_gamma.c
index f1a0b18b6c1a..e0e2d2bdbf59 100644
--- a/drivers/gpu/drm/mediatek/mtk_disp_gamma.c
+++ b/drivers/gpu/drm/mediatek/mtk_disp_gamma.c
@@ -27,12 +27,20 @@
#define DISP_GAMMA_SIZE_VSIZE GENMASK(12, 0)
#define DISP_GAMMA_BANK 0x0100
#define DISP_GAMMA_BANK_BANK GENMASK(1, 0)
+#define DISP_GAMMA_BANK_DATA_MODE BIT(2)
#define DISP_GAMMA_LUT 0x0700
+#define DISP_GAMMA_LUT1 0x0b00

+/* For 10 bit LUT layout, R/G/B are in the same register */
#define DISP_GAMMA_LUT_10BIT_R GENMASK(29, 20)
#define DISP_GAMMA_LUT_10BIT_G GENMASK(19, 10)
#define DISP_GAMMA_LUT_10BIT_B GENMASK(9, 0)

+/* For 12 bit LUT layout, R/G are in LUT, B is in LUT1 */
+#define DISP_GAMMA_LUT_12BIT_R GENMASK(11, 0)
+#define DISP_GAMMA_LUT_12BIT_G GENMASK(23, 12)
+#define DISP_GAMMA_LUT_12BIT_B GENMASK(11, 0)
+
#define LUT_10BIT_MASK 0x03ff
#define LUT_BITS_DEFAULT 10
#define LUT_SIZE_DEFAULT 512
@@ -83,14 +91,15 @@ unsigned int mtk_gamma_get_lut_size(struct device *dev)
void mtk_gamma_set_common(struct device *dev, void __iomem *regs, struct drm_crtc_state *state)
{
struct mtk_disp_gamma *gamma = dev_get_drvdata(dev);
- unsigned int i;
+ void __iomem *lut0_base = regs + DISP_GAMMA_LUT;
+ void __iomem *lut1_base = regs + DISP_GAMMA_LUT1;
+ u32 cfg_val, data_mode, lbank_val, word[2];
+ int cur_bank, num_lut_banks;
+ u16 lut_bank_size, lut_size;
struct drm_color_lut *lut;
- void __iomem *lut_base;
+ unsigned int i;
bool lut_diff;
- u16 lut_bank_size, lut_size;
u8 lut_bits;
- u32 cfg_val, lbank_val, word;
- int cur_bank, num_lut_banks;

/* If there's no gamma lut there's nothing to do here. */
if (!state->gamma_lut)
@@ -110,14 +119,17 @@ void mtk_gamma_set_common(struct device *dev, void __iomem *regs, struct drm_crt
num_lut_banks = lut_size / lut_bank_size;

cfg_val = readl(regs + DISP_GAMMA_CFG);
- lut_base = regs + DISP_GAMMA_LUT;
lut = (struct drm_color_lut *)state->gamma_lut->data;

+ /* Switch to 12 bits data mode if supported */
+ data_mode = FIELD_PREP(DISP_GAMMA_BANK_DATA_MODE, !!(lut_bits == 12));
+
for (cur_bank = 0; cur_bank < num_lut_banks; cur_bank++) {

/* Switch gamma bank and set data mode before writing LUT */
if (num_lut_banks > 1) {
lbank_val = FIELD_PREP(DISP_GAMMA_BANK_BANK, cur_bank);
+ lbank_val |= data_mode;
writel(lbank_val, regs + DISP_GAMMA_BANK);
}

@@ -130,9 +142,15 @@ void mtk_gamma_set_common(struct device *dev, void __iomem *regs, struct drm_crt
hwlut.blue = drm_color_lut_extract(lut[n].blue, lut_bits);

if (!lut_diff || (i % 2 == 0)) {
- word = FIELD_PREP(DISP_GAMMA_LUT_10BIT_R, hwlut.red);
- word |= FIELD_PREP(DISP_GAMMA_LUT_10BIT_G, hwlut.green);
- word |= FIELD_PREP(DISP_GAMMA_LUT_10BIT_B, hwlut.blue);
+ if (lut_bits == 12) {
+ word[0] = FIELD_PREP(DISP_GAMMA_LUT_12BIT_R, hwlut.red);
+ word[0] |= FIELD_PREP(DISP_GAMMA_LUT_12BIT_G, hwlut.green);
+ word[1] = FIELD_PREP(DISP_GAMMA_LUT_12BIT_B, hwlut.blue);
+ } else {
+ word[0] = FIELD_PREP(DISP_GAMMA_LUT_10BIT_R, hwlut.red);
+ word[0] |= FIELD_PREP(DISP_GAMMA_LUT_10BIT_G, hwlut.green);
+ word[0] |= FIELD_PREP(DISP_GAMMA_LUT_10BIT_B, hwlut.blue);
+ }
} else {
diff.red = lut[n].red - lut[n - 1].red;
diff.red = drm_color_lut_extract(diff.red, lut_bits);
@@ -143,11 +161,19 @@ void mtk_gamma_set_common(struct device *dev, void __iomem *regs, struct drm_crt
diff.blue = lut[n].blue - lut[n - 1].blue;
diff.blue = drm_color_lut_extract(diff.blue, lut_bits);

- word = FIELD_PREP(DISP_GAMMA_LUT_10BIT_R, diff.red);
- word |= FIELD_PREP(DISP_GAMMA_LUT_10BIT_G, diff.green);
- word |= FIELD_PREP(DISP_GAMMA_LUT_10BIT_B, diff.blue);
+ if (lut_bits == 12) {
+ word[0] = FIELD_PREP(DISP_GAMMA_LUT_12BIT_R, diff.red);
+ word[0] |= FIELD_PREP(DISP_GAMMA_LUT_12BIT_G, diff.green);
+ word[1] = FIELD_PREP(DISP_GAMMA_LUT_12BIT_B, diff.blue);
+ } else {
+ word[0] = FIELD_PREP(DISP_GAMMA_LUT_10BIT_R, diff.red);
+ word[0] |= FIELD_PREP(DISP_GAMMA_LUT_10BIT_G, diff.green);
+ word[0] |= FIELD_PREP(DISP_GAMMA_LUT_10BIT_B, diff.blue);
+ }
}
- writel(word, (lut_base + i * 4));
+ writel(word[0], (lut0_base + i * 4));
+ if (lut_bits == 12)
+ writel(word[1], (lut1_base + i * 4));
}
}

@@ -271,11 +297,20 @@ static const struct mtk_disp_gamma_data mt8183_gamma_driver_data = {
.lut_size = 512,
};

+static const struct mtk_disp_gamma_data mt8195_gamma_driver_data = {
+ .lut_bank_size = 256,
+ .lut_bits = 12,
+ .lut_diff = true,
+ .lut_size = 1024,
+};
+
static const struct of_device_id mtk_disp_gamma_driver_dt_match[] = {
{ .compatible = "mediatek,mt8173-disp-gamma",
.data = &mt8173_gamma_driver_data},
{ .compatible = "mediatek,mt8183-disp-gamma",
.data = &mt8183_gamma_driver_data},
+ { .compatible = "mediatek,mt8195-disp-gamma",
+ .data = &mt8195_gamma_driver_data},
{},
};
MODULE_DEVICE_TABLE(of, mtk_disp_gamma_driver_dt_match);
--
2.40.1