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

[Jason-JH Lin <jason-jh.lin@mediatek.com>]

On Wed, 2022-08-31 at 10:56 +0800, CK Hu wrote:
> 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


Hi CK,

Thanks for the reviews.

I'll help Zheng-yan finish this series.

I'll separate this one patch to the patches below:
drm/mediatek: Adjust mtk_drm_gamma_set_common parameters
drm/mediatek: Add gamma support different lut_size for other SoC
drm/mediatek: Add gamma support different lut_bits for other SoC
drm/mediatek: Add gamma support different bank_size for other SoC
drm/mediatek: Add gamma lut support for mt8195
drm/mediatek: Add clear RELAY_MODE bit to set gamma

Regrads,
Jason-JH.Lin