Re: [PATCH RESEND v3 7/9] drm/mediatek: Add gamma lut support for mt8195

[CK Hu <ck.hu@mediatek.com>]

Hi, Jason:

On Mon, 2022-09-12 at 09:30 +0800, Jason-JH.Lin wrote:
> From: "zheng-yan.chen" <zheng-yan.chen@mediatek.com>
> 
> Since the previous gamma_set_common() function is designed for
> 9bit-to-10bit conversion, which is not feasible for the
> 10bit-to-12bit conversion in mt8195.
> 
> 1. Update the function to fit the need of mt8195.
> 2. Add gamma driver data for mt8195.
> 
> Signed-off-by: zheng-yan.chen <zheng-yan.chen@mediatek.com>
> Signed-off-by: Jason-JH.Lin <jason-jh.lin@mediatek.com>
> ---
>  drivers/gpu/drm/mediatek/mtk_disp_gamma.c | 57 ++++++++++++++++-----
> --
>  1 file changed, 40 insertions(+), 17 deletions(-)
> 
> diff --git a/drivers/gpu/drm/mediatek/mtk_disp_gamma.c
> b/drivers/gpu/drm/mediatek/mtk_disp_gamma.c
> index 45da2b6206c8..d706f76fd30e 100644
> --- a/drivers/gpu/drm/mediatek/mtk_disp_gamma.c
> +++ b/drivers/gpu/drm/mediatek/mtk_disp_gamma.c
> @@ -23,6 +23,7 @@
>  #define DISP_GAMMA_SIZE				0x0030
>  #define DISP_GAMMA_BANK				0x0100
>  #define DISP_GAMMA_LUT				0x0700
> +#define DISP_GAMMA_LUT1				0x0b00
>  
>  #define LUT_10BIT_MASK				0x03ff
>  #define LUT_SIZE_DEFAULT			512 /* for setting
> gamma lut from AAL */
> @@ -82,9 +83,8 @@ void mtk_gamma_set_common(struct device *dev, void
> __iomem *regs, struct drm_crt
>  	u8 shift_bits;
>  	unsigned int i, j, reg, bank_num;
>  	struct drm_color_lut *lut;
> -	void __iomem *lut_base;
> -	u32 word, mask;
> -	u32 diff[3] = {0};
> +	void __iomem *lut_base, *lut1_base;
> +	u32 word, word1, mask;
>  
>  	if (gamma && gamma->data) {
>  		lut_diff = gamma->data->lut_diff;
> @@ -102,27 +102,41 @@ void mtk_gamma_set_common(struct device *dev,
> void __iomem *regs, struct drm_crt
>  		reg = reg | GAMMA_LUT_EN;
>  		writel(reg, regs + DISP_GAMMA_CFG);
>  		lut_base = regs + DISP_GAMMA_LUT;
> +		lut1_base = regs + DISP_GAMMA_LUT1;
>  		lut = (struct drm_color_lut *)state->gamma_lut->data;
>  		for (j = 0; j < bank_num; j++) {
>  			writel(j, regs + DISP_GAMMA_BANK);
>  			for (i = 0; i < bank_size; i++) {
> -				if (!lut_diff || (i % 2 == 0)) {
> -					word = (((lut[i].red >>
> shift_bits) & mask) << 20) +
> -						(((lut[i].green >>
> shift_bits) & mask) << 10) +
> -						((lut[i].blue >>
> shift_bits) & mask);
> +				struct drm_color_lut input;
> +
> +				input.red = (lut[i].red >> shift_bits)
> & mask;
> +				input.green = (lut[i].green >>
> shift_bits) & mask;
> +				input.blue = (lut[i].blue >>
> shift_bits) & mask;
> +				if (!lut_diff || i % 2 == 0) {
> +					word = (lut_bits == 12) ?

Move lut_bits modification to the patch "drm/mediatek: Add gamma
support different lut_bits for other SoC".

> +					       (input.red +
> (input.green << 12)) :
> +					       ((input.red << 20) +
> (input.green << 10) +
> +						input.blue);
> +					word1 = input.blue;
>  				} else {
> -					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);
> +					struct drm_color_lut diff;
> +
> +					diff.red = input.red  -
> +						   ((lut[i - 1].red >>
> shift_bits) & mask);
> +					diff.green = input.green -
> +						     ((lut[i - 1].green
> >> shift_bits & mask));
> +					diff.blue = input.blue -
> +						    ((lut[i - 1].blue
> >> shift_bits) & mask);
> +
> +					word = (lut_bits == 12) ?

Ditto.

> +					       (input.red +
> (input.green << 12)) :
> +					       (diff.red << 20) +
> (diff.green << 10) + diff.blue;
> +					word1 = input.blue;
>  				}
> +
>  				writel(word, (lut_base + i * 4));
> +				if (lut_bits == 12)

Ditto.

Regards,
CK

> +					writel(word1, (lut1_base + i *
> 4));
>  			}
>  		}
>  	}
> @@ -237,11 +251,20 @@ static const struct mtk_disp_gamma_data
> mt8183_gamma_driver_data = {
>  	.lut_bits = 10,
>  };
>  
> +static const struct mtk_disp_gamma_data mt8195_gamma_driver_data = {
> +	.lut_diff = true,
> +	.lut_size = 512,
> +	.lut_bits = 10,
> +	.bank_size = 256,
> +};
> +
>  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},
>  	{},
>  };
>  MODULE_DEVICE_TABLE(of, mtk_disp_gamma_driver_dt_match);


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