[PATCH v10 11/16] drm/mediatek: gamma: Add support for 12-bit LUT and MT8195

Chen-Yu Tsai wenst at chromium.org
Tue Aug 15 07:57:28 UTC 2023


On Fri, Aug 4, 2023 at 3:29 PM AngeloGioacchino Del Regno
<angelogioacchino.delregno at collabora.com> wrote:
>
> 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 at collabora.com>
> Reviewed-by: Jason-JH.Lin <jason-jh.lin at mediatek.com>
> Reviewed-by: Alexandre Mergnat <amergnat at baylibre.com>
> ---
>  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},

I assume we need matching changes for the DT binding and to the DT?

ChenYu

>         {},
>  };
>  MODULE_DEVICE_TABLE(of, mtk_disp_gamma_driver_dt_match);
> --
> 2.41.0
>


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