Re: [PATCH v2 2/3] drm/mediatek: Add gamma lut support for mt8195

* Re: [PATCH v2 2/3] drm/mediatek: Add gamma lut support for mt8195
       [not found] ` <20220830063929.13390-3-zheng-yan.chen@mediatek.com>
@ 2022-08-30  7:47   ` AngeloGioacchino Del Regno
  0 siblings, 0 replies; 8+ messages in thread
From: AngeloGioacchino Del Regno @ 2022-08-30  7:47 UTC (permalink / raw)
  To: zheng-yan.chen, Chun-Kuang Hu, Rob Herring, Krzysztof Kozlowski,
	Matthias Brugger
  Cc: dri-devel, linux-mediatek, devicetree, linux-kernel,
	linux-arm-kernel, Jason-JH . Lin, Singo Chang,
	Project_Global_Chrome_Upstream_Group

Il 30/08/22 08:39, zheng-yan.chen ha scritto:
> 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.
> 
> Update the function to fit the need of mt8195.
> 
> Fixes: 7266e90a51a3 ("drm/mediatek: Add mediatek-drm of vdosys0 support for mt8195")
> Signed-off-by: zheng-yan.chen <zheng-yan.chen@mediatek.com>
> ---
>   drivers/gpu/drm/mediatek/mtk_disp_aal.c     |   2 +-
>   drivers/gpu/drm/mediatek/mtk_disp_drv.h     |   3 +-
>   drivers/gpu/drm/mediatek/mtk_disp_gamma.c   | 102 +++++++++++++++-----
>   drivers/gpu/drm/mediatek/mtk_drm_crtc.c     |   5 +-
>   drivers/gpu/drm/mediatek/mtk_drm_crtc.h     |   1 -
>   drivers/gpu/drm/mediatek/mtk_drm_ddp_comp.c |   1 +
>   drivers/gpu/drm/mediatek/mtk_drm_ddp_comp.h |   1 +
>   drivers/gpu/drm/mediatek/mtk_drm_drv.c      |   2 +
>   8 files changed, 85 insertions(+), 32 deletions(-)
> 
> diff --git a/drivers/gpu/drm/mediatek/mtk_disp_aal.c b/drivers/gpu/drm/mediatek/mtk_disp_aal.c
> index 0f9d7efb61d7..f563eee3c330 100644
> --- a/drivers/gpu/drm/mediatek/mtk_disp_aal.c
> +++ b/drivers/gpu/drm/mediatek/mtk_disp_aal.c
> @@ -66,7 +66,7 @@ void mtk_aal_gamma_set(struct device *dev, struct drm_crtc_state *state)
>   	struct mtk_disp_aal *aal = dev_get_drvdata(dev);
>   
>   	if (aal->data && aal->data->has_gamma)
> -		mtk_gamma_set_common(aal->regs, state, false);
> +		mtk_gamma_set_common(aal->regs, state, dev);
>   }
>   
>   void mtk_aal_start(struct device *dev)
> diff --git a/drivers/gpu/drm/mediatek/mtk_disp_drv.h b/drivers/gpu/drm/mediatek/mtk_disp_drv.h
> index 33e61a136bbc..c1269fce9a66 100644
> --- a/drivers/gpu/drm/mediatek/mtk_disp_drv.h
> +++ b/drivers/gpu/drm/mediatek/mtk_disp_drv.h
> @@ -51,8 +51,9 @@ void mtk_gamma_clk_disable(struct device *dev);
>   void mtk_gamma_config(struct device *dev, unsigned int w,
>   		      unsigned int h, unsigned int vrefresh,
>   		      unsigned int bpc, struct cmdq_pkt *cmdq_pkt);
> +unsigned int mtk_gamma_size(struct device *dev);
>   void mtk_gamma_set(struct device *dev, struct drm_crtc_state *state);
> -void mtk_gamma_set_common(void __iomem *regs, struct drm_crtc_state *state, bool lut_diff);
> +void mtk_gamma_set_common(void __iomem *regs, struct drm_crtc_state *state, struct device *dev);
>   void mtk_gamma_start(struct device *dev);
>   void mtk_gamma_stop(struct device *dev);
>   
> diff --git a/drivers/gpu/drm/mediatek/mtk_disp_gamma.c b/drivers/gpu/drm/mediatek/mtk_disp_gamma.c
> index bbd558a036ec..0409e15fceb3 100644
> --- a/drivers/gpu/drm/mediatek/mtk_disp_gamma.c
> +++ b/drivers/gpu/drm/mediatek/mtk_disp_gamma.c
> @@ -18,18 +18,22 @@
>   #define DISP_GAMMA_EN				0x0000
>   #define GAMMA_EN					BIT(0)
>   #define DISP_GAMMA_CFG				0x0020
> +#define RELAY_MODE					BIT(0)
>   #define GAMMA_LUT_EN					BIT(1)
>   #define GAMMA_DITHERING					BIT(2)
>   #define DISP_GAMMA_SIZE				0x0030
> +#define DISP_GAMMA_BANK				0x0100
>   #define DISP_GAMMA_LUT				0x0700
> -
> -#define LUT_10BIT_MASK				0x03ff
> -
> +#define DISP_GAMMA_LUT1				0x0b00

> +#define TABLE_9BIT_SIZE				512
> +#define TABLE_10BIT_SIZE			1024

Please remove these two unused definitions.

> +#define BANK_SIZE				256
>   struct mtk_disp_gamma_data {
>   	bool has_dither;
>   	bool lut_diff;
> +	unsigned int lut_size;
> +	unsigned int lut_bits;

We can reduce the size of this structure by using

	u16 lut_size;
	u8 lut_bits;

>   };
> -
>   /*
>    * struct mtk_disp_gamma - DISP_GAMMA driver structure
>    */
> @@ -54,40 +58,75 @@ void mtk_gamma_clk_disable(struct device *dev)
>   	clk_disable_unprepare(gamma->clk);
>   }
>   
> -void mtk_gamma_set_common(void __iomem *regs, struct drm_crtc_state *state, bool lut_diff)
> +void mtk_gamma_set_common(void __iomem *regs, struct drm_crtc_state *state, struct device *dev)
>   {
> -	unsigned int i, reg;
> -	struct drm_color_lut *lut;
> +	unsigned int i, reg, idx;
>   	void __iomem *lut_base;
> -	u32 word;
> -	u32 diff[3] = {0};
> +	void __iomem *lut1_base;
> +	u32 word, word1;
> +	struct mtk_disp_gamma *gamma = dev_get_drvdata(dev);

Please reorder these definitions, (columns) longest first, shortest last

>   
>   	if (state->gamma_lut) {
> +		u32 table_size;
> +		u32 mask;
> +		u32 lut_bits;
> +		u32 shift_bits;
> +		bool lut_diff;
> +		struct drm_color_lut color, color_rec;
> +		struct drm_color_lut *lut = (struct drm_color_lut *)state->gamma_lut;

struct drm_color_lut *lut = (struct drm_color_lut *)state->gamma_lut;
struct drm_color_lut color, color_rec;
u32 lut_bits, shift_bits;
u32 mask, table_size;
bool lut_diff;

> +
> +		table_size = gamma->data->lut_size;
> +		lut_bits = gamma->data->lut_bits;
> +		lut_diff = gamma->data->lut_diff;
> +		shift_bits = (lut_bits == 12) ? 4 : 6;
> +		mask = GENMASK(lut_bits - 1, 0);
>   		reg = readl(regs + DISP_GAMMA_CFG);
> +		reg = reg & ~RELAY_MODE;
>   		reg = reg | GAMMA_LUT_EN;
>   		writel(reg, regs + DISP_GAMMA_CFG);
>   		lut_base = regs + DISP_GAMMA_LUT;
> -		lut = (struct drm_color_lut *)state->gamma_lut->data;
> -		for (i = 0; i < MTK_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);
> +		lut1_base = regs + DISP_GAMMA_LUT1;
> +		for (i = 0; i < table_size; i++) {
> +			color.red = (lut[i].red >> shift_bits) & mask;
> +			color.green = (lut[i].green >> shift_bits) & mask;
> +			color.blue = (lut[i].blue >> shift_bits) & mask;
> +			if (lut_diff && (i % 2)) {
> +				word = (lut_bits == 12) ?
> +						      (((color.green - color_rec.green) << 12) +
> +						      (color.red - color_rec.red))
> +							:
> +						      (((color.red - color_rec.red) << 20) +
> +						      ((color.green - color_rec.green) << 10) +
> +						      (color.blue - color_rec.blue));
> +				word1 = (color.blue - color_rec.blue);
>   			} 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);
> +				word = (lut_bits == 12) ?
> +						      ((color.green << 12) + color.red)
> +							:
> +						      ((color.red << 20) +
> +						      (color.green << 10) + color.blue);
> +				word1 = color.blue;
> +				color_rec = color;
>   			}
> -			writel(word, (lut_base + i * 4));
> +			idx = (lut_bits == 12) ? (i % BANK_SIZE) : i;
> +			writel(word, (lut_base + idx * 4));
> +			if (!(i % BANK_SIZE) && lut_bits == 12)
> +				writel((i / BANK_SIZE), regs + DISP_GAMMA_BANK);
> +			if (lut_bits == 12)
> +				writel(word1, (lut1_base + idx * 4));
>   		}
>   	}
>   }
>   
> +unsigned int mtk_gamma_size(struct device *dev)

unsigned int mtk_gamma_get_lut_size(struct device *dev)

that looks a bit more readable and perfectly explains this function :-)

> +{
> +	struct mtk_disp_gamma *gamma = dev_get_drvdata(dev);
> +
> +	if (gamma->data)
> +		return gamma->data->lut_size;
> +	else
> +		return 0;
> +}
>   void mtk_gamma_set(struct device *dev, struct drm_crtc_state *state)
>   {
>   	struct mtk_disp_gamma *gamma = dev_get_drvdata(dev);

..snip..

> diff --git a/drivers/gpu/drm/mediatek/mtk_drm_ddp_comp.c b/drivers/gpu/drm/mediatek/mtk_drm_ddp_comp.c
> index 2d72cc5ddaba..4c6538a17b88 100644
> --- a/drivers/gpu/drm/mediatek/mtk_drm_ddp_comp.c
> +++ b/drivers/gpu/drm/mediatek/mtk_drm_ddp_comp.c
> @@ -323,6 +323,7 @@ static const struct mtk_ddp_comp_funcs ddp_gamma = {
>   	.clk_enable = mtk_gamma_clk_enable,
>   	.clk_disable = mtk_gamma_clk_disable,
>   	.gamma_set = mtk_gamma_set,
> +	.gamma_size = mtk_gamma_size,
>   	.config = mtk_gamma_config,
>   	.start = mtk_gamma_start,
>   	.stop = mtk_gamma_stop,
> diff --git a/drivers/gpu/drm/mediatek/mtk_drm_ddp_comp.h b/drivers/gpu/drm/mediatek/mtk_drm_ddp_comp.h
> index 2d0052c23dcb..bf0cf7f86010 100644
> --- a/drivers/gpu/drm/mediatek/mtk_drm_ddp_comp.h
> +++ b/drivers/gpu/drm/mediatek/mtk_drm_ddp_comp.h
> @@ -59,6 +59,7 @@ struct mtk_ddp_comp_funcs {
>   	void (*disable_vblank)(struct device *dev);
>   	unsigned int (*supported_rotations)(struct device *dev);
>   	unsigned int (*layer_nr)(struct device *dev);
> +	unsigned int (*gamma_size)(struct device *dev);

	unsigned int (*gamma_get_lut_size)(struct device *dev);

>   	int (*layer_check)(struct device *dev,
>   			   unsigned int idx,
>   			   struct mtk_plane_state *state);

Regards,
Angelo

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