[PATCH RESEND v3 5/9] drm/mediatek: Add gamma support different lut_bits for other SoC

[CK Hu]

Hi, Jason:

On Mon, 2022-09-12 at 09:30 +0800, Jason-JH.Lin wrote:
> Add lut_bits in gamma driver data for each SoC and adjust the usage
> of lut_bits in mtk_drm_gamma_set_common().
> 
> Signed-off-by: Jason-JH.Lin <jason-jh.lin at mediatek.com>
> ---
>  drivers/gpu/drm/mediatek/mtk_disp_gamma.c | 36 ++++++++++++++++-----
> --
>  1 file changed, 25 insertions(+), 11 deletions(-)
> 
> diff --git a/drivers/gpu/drm/mediatek/mtk_disp_gamma.c
> b/drivers/gpu/drm/mediatek/mtk_disp_gamma.c
> index 0a1022032b71..be82d15a5204 100644
> --- a/drivers/gpu/drm/mediatek/mtk_disp_gamma.c
> +++ b/drivers/gpu/drm/mediatek/mtk_disp_gamma.c
> @@ -25,11 +25,14 @@
>  
>  #define LUT_10BIT_MASK				0x03ff
>  #define LUT_SIZE_DEFAULT			512 /* for setting
> gamma lut from AAL */
> +#define LUT_BITS_DEFAULT			10
> +#define LUT_INPUT_BITS				16 /* input lut
> bit from application */

I think we should use drm_color_lut_extract() to let the input bits
transparent. So add one patch to use drm_color_lut_extract(), and then
apply this patch.

Regards,
CK

>  
>  struct mtk_disp_gamma_data {
>  	bool has_dither;
>  	bool lut_diff;
>  	u16 lut_size;
> +	u8 lut_bits;
>  };
>  
>  /*
> @@ -72,17 +75,23 @@ void mtk_gamma_set_common(struct device *dev,
> void __iomem *regs, struct drm_crt
>  	struct mtk_disp_gamma *gamma = dev_get_drvdata(dev);
>  	bool lut_diff = false;
>  	u16 lut_size = LUT_SIZE_DEFAULT;
> +	u8 lut_bits = LUT_BITS_DEFAULT;
> +	u8 shift_bits;
>  	unsigned int i, reg;
>  	struct drm_color_lut *lut;
>  	void __iomem *lut_base;
> -	u32 word;
> +	u32 word, mask;
>  	u32 diff[3] = {0};
>  
>  	if (gamma && gamma->data) {
>  		lut_diff = gamma->data->lut_diff;
>  		lut_size = gamma->data->lut_size;
> +		lut_bits = gamma->data->lut_bits;
>  	}
>  
> +	shift_bits = LUT_INPUT_BITS - lut_bits;
> +	mask = GENMASK(lut_bits - 1, 0);
> +
>  	if (state->gamma_lut) {
>  		reg = readl(regs + DISP_GAMMA_CFG);
>  		reg = reg | GAMMA_LUT_EN;
> @@ -92,17 +101,20 @@ void mtk_gamma_set_common(struct device *dev,
> void __iomem *regs, struct drm_crt
>  		for (i = 0; i < lut_size; i++) {
>  
>  			if (!lut_diff || (i % 2 == 0)) {
> -				word = (((lut[i].red >> 6) &
> LUT_10BIT_MASK) << 20) +
> -					(((lut[i].green >> 6) &
> LUT_10BIT_MASK) << 10) +
> -					((lut[i].blue >> 6) &
> LUT_10BIT_MASK);
> +				word = (((lut[i].red >> shift_bits) &
> mask) << 20) +
> +					(((lut[i].green >> shift_bits)
> & mask) << 10) +
> +					((lut[i].blue >> shift_bits) &
> mask);
>  			} else {
> -				diff[0] = (lut[i].red >> 6) - (lut[i -
> 1].red >> 6);
> -				diff[1] = (lut[i].green >> 6) - (lut[i
> - 1].green >> 6);
> -				diff[2] = (lut[i].blue >> 6) - (lut[i -
> 1].blue >> 6);
> -
> -				word = ((diff[0] & LUT_10BIT_MASK) <<
> 20) +
> -					((diff[1] & LUT_10BIT_MASK) <<
> 10) +
> -					(diff[2] & LUT_10BIT_MASK);
> +				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);
>  			}
>  			writel(word, (lut_base + i * 4));
>  		}
> @@ -209,11 +221,13 @@ 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_size = 512,
> +	.lut_bits = 10,
>  };
>  
>  static const struct mtk_disp_gamma_data mt8183_gamma_driver_data = {
>  	.lut_diff = true,
>  	.lut_size = 512,
> +	.lut_bits = 10,
>  };
>  
>  static const struct of_device_id mtk_disp_gamma_driver_dt_match[] =
> {