[PATCH v3 7/9] drm/mediatek: Add gamma lut support for mt8195

[Jason-JH.Lin]

From: "zheng-yan.chen" <zheng-yan.chen at mediatek.com>

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.

1. Update the function to fit the need of mt8195.
2. Add gamma driver data for mt8195.

Signed-off-by: zheng-yan.chen <zheng-yan.chen at mediatek.com>
Signed-off-by: Jason-JH.Lin <jason-jh.lin at mediatek.com>
---
 drivers/gpu/drm/mediatek/mtk_disp_gamma.c | 57 ++++++++++++++++-------
 1 file changed, 40 insertions(+), 17 deletions(-)

diff --git a/drivers/gpu/drm/mediatek/mtk_disp_gamma.c b/drivers/gpu/drm/mediatek/mtk_disp_gamma.c
index 9983318e8e3e..4e67f1503b9a 100644
--- a/drivers/gpu/drm/mediatek/mtk_disp_gamma.c
+++ b/drivers/gpu/drm/mediatek/mtk_disp_gamma.c
@@ -23,6 +23,7 @@
 #define DISP_GAMMA_SIZE				0x0030
 #define DISP_GAMMA_BANK				0x0100
 #define DISP_GAMMA_LUT				0x0700
+#define DISP_GAMMA_LUT1				0x0b00
 
 #define LUT_10BIT_MASK				0x03ff
 #define LUT_SIZE_DEFAULT			512 /* for setting gamma lut from AAL */
@@ -82,9 +83,8 @@ void mtk_gamma_set_common(struct device *dev, void __iomem *regs, struct drm_crt
 	u8 shift_bits;
 	unsigned int i, j, reg, bank_num;
 	struct drm_color_lut *lut;
-	void __iomem *lut_base;
-	u32 word, mask;
-	u32 diff[3] = {0};
+	void __iomem *lut_base, *lut1_base;
+	u32 word, word1, mask;
 
 	if (gamma && gamma->data) {
 		lut_diff = gamma->data->lut_diff;
@@ -102,27 +102,41 @@ void mtk_gamma_set_common(struct device *dev, void __iomem *regs, struct drm_crt
 		reg = reg | GAMMA_LUT_EN;
 		writel(reg, regs + DISP_GAMMA_CFG);
 		lut_base = regs + DISP_GAMMA_LUT;
+		lut1_base = regs + DISP_GAMMA_LUT1;
 		lut = (struct drm_color_lut *)state->gamma_lut->data;
 		for (j = 0; j < bank_num; j++) {
 			writel(j, regs + DISP_GAMMA_BANK);
 			for (i = 0; i < bank_size; i++) {
-				if (!lut_diff || (i % 2 == 0)) {
-					word = (((lut[i].red >> shift_bits) & mask) << 20) +
-						(((lut[i].green >> shift_bits) & mask) << 10) +
-						((lut[i].blue >> shift_bits) & mask);
+				struct drm_color_lut input;
+
+				input.red = (lut[i].red >> shift_bits) & mask;
+				input.green = (lut[i].green >> shift_bits) & mask;
+				input.blue = (lut[i].blue >> shift_bits) & mask;
+				if (!lut_diff || i % 2 == 0) {
+					word = (lut_bits == 12) ?
+					       (input.red + (input.green << 12)) :
+					       ((input.red << 20) + (input.green << 10) +
+						input.blue);
+					word1 = input.blue;
 				} else {
-					diff[0] = (lut[i].red >> shift_bits) -
-						  (lut[i - 1].red >> shift_bits);
-					diff[1] = (lut[i].green >> shift_bits) -
-						  (lut[i - 1].green >> shift_bits);
-					diff[2] = (lut[i].blue >> shift_bits) -
-						  (lut[i - 1].blue >> shift_bits);
-
-					word = ((diff[0] & mask) << 20) +
-						((diff[1] & mask) << 10) +
-						(diff[2] & mask);
+					struct drm_color_lut diff;
+
+					diff.red = input.red  -
+						   ((lut[i - 1].red >> shift_bits) & mask);
+					diff.green = input.green -
+						     ((lut[i - 1].green >> shift_bits & mask));
+					diff.blue = input.blue -
+						    ((lut[i - 1].blue >> shift_bits) & mask);
+
+					word = (lut_bits == 12) ?
+					       (input.red + (input.green << 12)) :
+					       (diff.red << 20) + (diff.green << 10) + diff.blue;
+					word1 = input.blue;
 				}
+
 				writel(word, (lut_base + i * 4));
+				if (lut_bits == 12)
+					writel(word1, (lut1_base + i * 4));
 			}
 		}
 	}
@@ -237,11 +251,20 @@ static const struct mtk_disp_gamma_data mt8183_gamma_driver_data = {
 	.lut_bits = 10,
 };
 
+static const struct mtk_disp_gamma_data mt8195_gamma_driver_data = {
+	.lut_diff = true,
+	.lut_size = 512,
+	.lut_bits = 10,
+	.bank_size = 256,
+};
+
 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);
-- 
2.18.0