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

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

Hi, Zheng-yan:

On Tue, 2022-08-30 at 14:39 +0800, zheng-yan.chen wrote:
> 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
> +#define BANK_SIZE				256
>  struct mtk_disp_gamma_data {
>  	bool has_dither;
>  	bool lut_diff;
> +	unsigned int lut_size;
> +	unsigned int 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);
>  
>  	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;
> +
> +		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);

This patch looks a little messy and mt8195 gamma introduce three
different things. So I would like to separate this patch to 4 patches.

1. Add multiple bank support. For other SoC, bank size is 0 which means
no bank support.
2. Support different lut_size: For other SoC, lut_size = 512
3. Support different lut_bits: For other SoC, lut_bits = 10
4. Add MT8195 gamma support, bank_size = 256, lut_size = 1024, lut_bits
= 12

In this view point, I think the last patch is not a bug-fix but a new
feature, so just drop the Fixes tag.

Regards,
CK

> +			if (lut_bits == 12)
> +				writel(word1, (lut1_base + idx * 4));
>  		}
>  	}
>  }
>  
> +unsigned int mtk_gamma_size(struct device *dev)
> +{
> +	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);
> @@ -95,8 +134,7 @@ void mtk_gamma_set(struct device *dev, struct
> drm_crtc_state *state)
>  
>  	if (gamma->data)
>  		lut_diff = gamma->data->lut_diff;
> -
> -	mtk_gamma_set_common(gamma->regs, state, lut_diff);
> +	mtk_gamma_set_common(gamma->regs, state, dev);
>  }
>  
>  void mtk_gamma_config(struct device *dev, unsigned int w,
> @@ -191,10 +229,20 @@ 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 mtk_disp_gamma_data mt8195_gamma_driver_data = {
> +	.lut_diff = true,
> +	.lut_size = 1024,
> +	.lut_bits = 12,
>  };
>  
>  static const struct of_device_id mtk_disp_gamma_driver_dt_match[] =
> {
> @@ -202,6 +250,8 @@ static const struct of_device_id
> mtk_disp_gamma_driver_dt_match[] = {
>  	  .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);
> diff --git a/drivers/gpu/drm/mediatek/mtk_drm_crtc.c
> b/drivers/gpu/drm/mediatek/mtk_drm_crtc.c
> index 42cc7052b050..2a6513259562 100644
> --- a/drivers/gpu/drm/mediatek/mtk_drm_crtc.c
> +++ b/drivers/gpu/drm/mediatek/mtk_drm_crtc.c
> @@ -930,9 +930,8 @@ int mtk_drm_crtc_create(struct drm_device
> *drm_dev,
>  		mtk_crtc->ddp_comp[i] = comp;
>  
>  		if (comp->funcs) {
> -			if (comp->funcs->gamma_set)
> -				gamma_lut_size = MTK_LUT_SIZE;
> -
> +			if (comp->funcs->gamma_set && comp->funcs-
> >gamma_size)
> +				gamma_lut_size = comp->funcs-
> >gamma_size(comp->dev);
>  			if (comp->funcs->ctm_set)
>  				has_ctm = true;
>  		}
> diff --git a/drivers/gpu/drm/mediatek/mtk_drm_crtc.h
> b/drivers/gpu/drm/mediatek/mtk_drm_crtc.h
> index cb9a36c48d4f..1799853ef89a 100644
> --- a/drivers/gpu/drm/mediatek/mtk_drm_crtc.h
> +++ b/drivers/gpu/drm/mediatek/mtk_drm_crtc.h
> @@ -10,7 +10,6 @@
>  #include "mtk_drm_ddp_comp.h"
>  #include "mtk_drm_plane.h"
>  
> -#define MTK_LUT_SIZE	512
>  #define MTK_MAX_BPC	10
>  #define MTK_MIN_BPC	3
>  
> 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);
>  	int (*layer_check)(struct device *dev,
>  			   unsigned int idx,
>  			   struct mtk_plane_state *state);
> diff --git a/drivers/gpu/drm/mediatek/mtk_drm_drv.c
> b/drivers/gpu/drm/mediatek/mtk_drm_drv.c
> index 0e4c77724b05..473766be56e1 100644
> --- a/drivers/gpu/drm/mediatek/mtk_drm_drv.c
> +++ b/drivers/gpu/drm/mediatek/mtk_drm_drv.c
> @@ -567,6 +567,8 @@ static const struct of_device_id
> mtk_ddp_comp_dt_ids[] = {
>  	  .data = (void *)MTK_DISP_GAMMA, },
>  	{ .compatible = "mediatek,mt8183-disp-gamma",
>  	  .data = (void *)MTK_DISP_GAMMA, },
> +	{ .compatible = "mediatek,mt8195-disp-gamma",
> +	  .data = (void *)MTK_DISP_GAMMA, },
>  	{ .compatible = "mediatek,mt8195-disp-merge",
>  	  .data = (void *)MTK_DISP_MERGE },
>  	{ .compatible = "mediatek,mt2701-disp-mutex",