Commit af0e042e authored by AngeloGioacchino Del Regno's avatar AngeloGioacchino Del Regno Committed by Chun-Kuang Hu
Browse files

drm/mediatek: gamma: Add support for 12-bit LUT 



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 calculations and add
support for 12-bit gamma lookup tables.

While at it, also reorder the variables in mtk_gamma_set_common()
and rename `lut_base` to `lut0_base` to improve readability.

Reviewed-by: default avatarJason-JH.Lin <jason-jh.lin@mediatek.com>
Reviewed-by: default avatarAlexandre Mergnat <amergnat@baylibre.com>
Signed-off-by: default avatarAngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Reviewed-by: default avatarCK Hu <ck.hu@mediatek.com>
Link: https://patchwork.kernel.org/project/dri-devel/patch/20231012095736.100784-11-angelogioacchino.delregno@collabora.com/


Signed-off-by: default avatarChun-Kuang Hu <chunkuang.hu@kernel.org>
parent 4708b01a

drivers/gpu/drm/mediatek/mtk_disp_gamma.c

+64 −19
Original line number Diff line number Diff line
@@ -26,17 +26,26 @@ 
#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)



struct mtk_disp_gamma_data {

	bool has_dither;

	bool lut_diff;

	u16 lut_bank_size;

	u16 lut_size;

	u8 lut_bits;

};



/*
@@ -72,28 +81,48 @@ unsigned int mtk_gamma_get_lut_size(struct device *dev) 
	return 0;

}



/*

 * 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];

	u8 lut_bits = gamma->data->lut_bits;

	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)

		return;



	num_lut_banks = gamma->data->lut_size / gamma->data->lut_bank_size;

	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, !!(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);

		}
@@ -101,29 +130,43 @@ void mtk_gamma_set(struct device *dev, struct drm_crtc_state *state) 
			int n = cur_bank * gamma->data->lut_bank_size + i;

			struct drm_color_lut diff, hwlut;



			hwlut.red = drm_color_lut_extract(lut[n].red, 10);

			hwlut.green = drm_color_lut_extract(lut[n].green, 10);

			hwlut.blue = drm_color_lut_extract(lut[n].blue, 10);

			hwlut.red = drm_color_lut_extract(lut[n].red, lut_bits);

			hwlut.green = drm_color_lut_extract(lut[n].green, lut_bits);

			hwlut.blue = drm_color_lut_extract(lut[n].blue, 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 (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, 10);

				diff.red = drm_color_lut_extract(diff.red, lut_bits);



				diff.green = lut[n].green - lut[n - 1].green;

				diff.green = drm_color_lut_extract(diff.green, 10);

				diff.green = drm_color_lut_extract(diff.green, lut_bits);



				diff.blue = lut[n].blue - lut[n - 1].blue;

				diff.blue = drm_color_lut_extract(diff.blue, 10);

				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);

		}

	}
@@ -229,11 +272,13 @@ static void mtk_disp_gamma_remove(struct platform_device *pdev) 
static const struct mtk_disp_gamma_data mt8173_gamma_driver_data = {

	.has_dither = true,

	.lut_bank_size = 512,

	.lut_bits = 10,

	.lut_size = 512,

};



static const struct mtk_disp_gamma_data mt8183_gamma_driver_data = {

	.lut_bank_size = 512,

	.lut_bits = 10,

	.lut_diff = true,

	.lut_size = 512,

};