[PATCH v10 09/16] drm/mediatek: gamma: Support specifying number of bits per LUT component

[CK Hu (胡俊光)]

Hi, Angelo:

On Fri, 2023-08-04 at 09:28 +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 calculation.

I would like to merge this patch with the 12-bit lut support.

> 
> 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 | 15 +++++++++------
>  1 file changed, 9 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/gpu/drm/mediatek/mtk_disp_gamma.c
> b/drivers/gpu/drm/mediatek/mtk_disp_gamma.c
> index 001b98694761..1845bd326a6d 100644
> --- a/drivers/gpu/drm/mediatek/mtk_disp_gamma.c
> +++ b/drivers/gpu/drm/mediatek/mtk_disp_gamma.c
> @@ -38,6 +38,7 @@ struct mtk_disp_gamma_data {
>  	bool has_dither;
>  	bool lut_diff;
>  	u16 lut_size;
> +	u8 lut_bits;
>  };
>  
>  /*
> @@ -91,9 +92,9 @@ void mtk_gamma_set(struct device *dev, struct
> drm_crtc_state *state)
>  	for (i = 0; i < gamma->data->lut_size; i++) {
>  		struct drm_color_lut diff, hwlut;
>  
> -		hwlut.red = drm_color_lut_extract(lut[i].red,
> LUT_BITS_DEFAULT);
> -		hwlut.green = drm_color_lut_extract(lut[i].green,
> LUT_BITS_DEFAULT);
> -		hwlut.blue = drm_color_lut_extract(lut[i].blue,
> LUT_BITS_DEFAULT);
> +		hwlut.red = drm_color_lut_extract(lut[i].red, gamma-
> >data->lut_bits);
> +		hwlut.green = drm_color_lut_extract(lut[i].green,
> gamma->data->lut_bits);
> +		hwlut.blue = drm_color_lut_extract(lut[i].blue, gamma-
> >data->lut_bits);
>  
>  		if (!gamma->data->lut_diff || (i % 2 == 0)) {
>  			word = FIELD_PREP(DISP_GAMMA_LUT_10BIT_R,
> hwlut.red);
> @@ -101,13 +102,13 @@ void mtk_gamma_set(struct device *dev, struct
> drm_crtc_state *state)
>  			word |= FIELD_PREP(DISP_GAMMA_LUT_10BIT_B,
> hwlut.blue);
>  		} else {
>  			diff.red = lut[i].red - lut[i - 1].red;
> -			diff.red = drm_color_lut_extract(diff.red,
> LUT_BITS_DEFAULT);
> +			diff.red = drm_color_lut_extract(diff.red,
> gamma->data->lut_bits);
>  
>  			diff.green = lut[i].green - lut[i - 1].green;
> -			diff.green = drm_color_lut_extract(diff.green,
> LUT_BITS_DEFAULT);
> +			diff.green = drm_color_lut_extract(diff.green,
> gamma->data->lut_bits);
>  
>  			diff.blue = lut[i].blue - lut[i - 1].blue;
> -			diff.blue = drm_color_lut_extract(diff.blue,
> LUT_BITS_DEFAULT);
> +			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);
> @@ -217,10 +218,12 @@ static int mtk_disp_gamma_remove(struct
> platform_device *pdev)
>  
>  static const struct mtk_disp_gamma_data mt8173_gamma_driver_data = {
>  	.has_dither = true,
> +	.lut_bits = 10,
>  	.lut_size = 512,
>  };
>  
>  static const struct mtk_disp_gamma_data mt8183_gamma_driver_data = {
> +	.lut_bits = 10,
>  	.lut_diff = true,
>  	.lut_size = 512,
>  };