[PATCH RESEND v6 07/11] drm/mediatek: gamma: Support specifying number of bits per LUT component

AngeloGioacchino Del Regno
2023-07-27T09:47:55Z

New SoCs, like MT8195, not only may support bigger lookup tables, but
have got a different register layout to support bigger precision:
support specifying the number of `lut_bits` for each SoC and use it
in mtk_gamma_set_common() to perform the right calculation.

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 | 18 ++++++++++++------
1 file changed, 12 insertions(+), 6 deletions(-)

diff --git a/drivers/gpu/drm/mediatek/mtk_disp_gamma.c b/drivers/gpu/drm/mediatek/mtk_disp_gamma.c
index f4bf5b37992c..407fb0264b80 100644
--- a/drivers/gpu/drm/mediatek/mtk_disp_gamma.c
+++ b/drivers/gpu/drm/mediatek/mtk_disp_gamma.c
@@ -39,6 +39,7 @@ struct mtk_disp_gamma_data {
bool has_dither;
bool lut_diff;
u16 lut_size;
+ u8 lut_bits;
};

/*
@@ -84,6 +85,7 @@ void mtk_gamma_set_common(struct device *dev, void __iomem *regs, struct drm_crt
void __iomem *lut_base;
bool lut_diff;
u16 lut_size;
+ u8 lut_bits;
u32 cfg_val, word;

/* If there's no gamma lut there's nothing to do here. */
@@ -92,9 +94,11 @@ void mtk_gamma_set_common(struct device *dev, void __iomem *regs, struct drm_crt

if (gamma && gamma->data) {
lut_diff = gamma->data->lut_diff;
+ lut_bits = gamma->data->lut_bits;
lut_size = gamma->data->lut_size;
} else {
lut_diff = false;
+ lut_bits = LUT_BITS_DEFAULT;
lut_size = LUT_SIZE_DEFAULT;
}

@@ -104,9 +108,9 @@ void mtk_gamma_set_common(struct device *dev, void __iomem *regs, struct drm_crt
for (i = 0; i < lut_size; i++) {
struct drm_color_lut diff, hwlut;

- hwlut.red = drm_color_lut_extract(lut[i].red, LUT_BITS_DEFAULT);
- hwlut.green = drm_color_lut_extract(lut[i].green, LUT_BITS_DEFAULT);
- hwlut.blue = drm_color_lut_extract(lut[i].blue, LUT_BITS_DEFAULT);
+ hwlut.red = drm_color_lut_extract(lut[i].red, lut_bits);
+ hwlut.green = drm_color_lut_extract(lut[i].green, lut_bits);
+ hwlut.blue = drm_color_lut_extract(lut[i].blue, lut_bits);

if (!lut_diff || (i % 2 == 0)) {
word = FIELD_PREP(DISP_GAMMA_LUT_10BIT_R, hwlut.red);
@@ -114,13 +118,13 @@ void mtk_gamma_set_common(struct device *dev, void __iomem *regs, struct drm_crt
word |= FIELD_PREP(DISP_GAMMA_LUT_10BIT_B, hwlut.blue);
} else {
diff.red = lut[i].red - lut[i - 1].red;
- diff.red = drm_color_lut_extract(diff.red, LUT_BITS_DEFAULT);
+ diff.red = drm_color_lut_extract(diff.red, lut_bits);

diff.green = lut[i].green - lut[i - 1].green;
- diff.green = drm_color_lut_extract(diff.green, LUT_BITS_DEFAULT);
+ diff.green = drm_color_lut_extract(diff.green, lut_bits);

diff.blue = lut[i].blue - lut[i - 1].blue;
- diff.blue = drm_color_lut_extract(diff.blue, LUT_BITS_DEFAULT);
+ 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);
@@ -237,10 +241,12 @@ static int mtk_disp_gamma_remove(struct platform_device *pdev)

static const struct mtk_disp_gamma_data mt8173_gamma_driver_data = {
.has_dither = true,
+ .lut_bits = 10,
.lut_size = 512,
};

static const struct mtk_disp_gamma_data mt8183_gamma_driver_data = {
+ .lut_bits = 10,
.lut_diff = true,
.lut_size = 512,
};
--
2.40.1