[PATCH v11 10/16] drm/mediatek: gamma: Add support for 12-bit LUT
CK Hu (胡俊光)
ck.hu at mediatek.com
Thu Oct 12 21:18:18 PDT 2023
Hi, Angelo:
On Thu, 2023-10-12 at 11:57 +0200, AngeloGioacchino Del Regno wrote:
> 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: CK Hu <ck.hu at mediatek.com>
>
> Reviewed-by: Jason-JH.Lin <jason-jh.lin at mediatek.com>
> Reviewed-by: Alexandre Mergnat <amergnat at baylibre.com>
> Signed-off-by: AngeloGioacchino Del Regno <
> angelogioacchino.delregno at collabora.com>
> ---
> drivers/gpu/drm/mediatek/mtk_disp_gamma.c | 83 +++++++++++++++++--
> ----
> 1 file changed, 64 insertions(+), 19 deletions(-)
>
> diff --git a/drivers/gpu/drm/mediatek/mtk_disp_gamma.c
> b/drivers/gpu/drm/mediatek/mtk_disp_gamma.c
> index 911468984ad5..6305cd95e6d4 100644
> --- a/drivers/gpu/drm/mediatek/mtk_disp_gamma.c
> +++ b/drivers/gpu/drm/mediatek/mtk_disp_gamma.c
> @@ -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);
> -
> - 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);
> + diff.blue =
> drm_color_lut_extract(diff.blue, lut_bits);
> +
> + 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);
> }
> }
>
> @@ -225,11 +268,13 @@ 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,
> };
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