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@xxxxxxxxxxxxx>
Reviewed-by: Jason-JH.Lin <jason-jh.lin@xxxxxxxxxxxx>
Reviewed-by: Alexandre Mergnat <amergnat@xxxxxxxxxxxx>
---
drivers/gpu/drm/mediatek/mtk_disp_gamma.c | 74 +++++++++++++++++++----
1 file changed, 62 insertions(+), 12 deletions(-)
diff --git a/drivers/gpu/drm/mediatek/mtk_disp_gamma.c b/drivers/gpu/drm/mediatek/mtk_disp_gamma.c
index 3f1c6815ea5a..7d2f8042ace0 100644
--- a/drivers/gpu/drm/mediatek/mtk_disp_gamma.c
+++ b/drivers/gpu/drm/mediatek/mtk_disp_gamma.c
@@ -26,12 +26,20 @@
#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
@@ -77,14 +85,30 @@ unsigned int mtk_gamma_get_lut_size(struct device *dev)
return LUT_SIZE_DEFAULT;
}
+/*
+ * SoCs supporting 12-bits LUTs are using a new register layout that does
+ * always support (by HW) both 12-bits and 10-bits LUT but, on those, we
+ * ignore the support for 10-bits in this driver and always use 12-bits.
+ *
+ * Summarizing:
+ * - SoC HW support 9/10-bits LUT only
+ * - Old register layout
+ * - 10-bits LUT supported
+ * - 9-bits LUT not supported
+ * - SoC HW support both 10/12bits LUT
+ * - New register layout
+ * - 12-bits LUT supported
+ * - 10-its LUT not supported
+ */
void mtk_gamma_set(struct device *dev, struct drm_crtc_state *state)
{
struct mtk_disp_gamma *gamma = dev_get_drvdata(dev);
- unsigned int i;
- struct drm_color_lut *lut;
- void __iomem *lut_base;
- u32 cfg_val, lbank_val, word;
+ void __iomem *lut0_base = gamma->regs + DISP_GAMMA_LUT;
+ void __iomem *lut1_base = gamma->regs + DISP_GAMMA_LUT1;
+ u32 cfg_val, data_mode, lbank_val, word[2];
int cur_bank, num_lut_banks;
+ struct drm_color_lut *lut;
+ unsigned int i;
/* If there's no gamma lut there's nothing to do here. */
if (!state->gamma_lut)
@@ -92,14 +116,17 @@ void mtk_gamma_set(struct device *dev, struct drm_crtc_state *state)
num_lut_banks = gamma->data->lut_size / gamma->data->lut_bank_size;
cfg_val = readl(gamma->regs + DISP_GAMMA_CFG);
- lut_base = gamma->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, !!(gamma->data->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, gamma->regs + DISP_GAMMA_BANK);
}
@@ -112,9 +139,15 @@ void mtk_gamma_set(struct device *dev, struct drm_crtc_state *state)
hwlut.blue = drm_color_lut_extract(lut[n].blue, gamma->data->lut_bits);
if (!gamma->data->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 (gamma->data->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, gamma->data->lut_bits);
@@ -125,11 +158,19 @@ void mtk_gamma_set(struct device *dev, struct drm_crtc_state *state)
diff.blue = lut[n].blue - lut[n - 1].blue;
diff.blue = drm_color_lut_extract(diff.blue, gamma->data->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 (gamma->data->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 (gamma->data->lut_bits == 12)
+ writel(word[1], (lut1_base + i * 4));
}
}
@@ -246,11 +287,20 @@ 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},
