Re: [PATCH v12 14/14] drm/mediatek: dpi: Add matrix_sel helper

[Rex-BC Chen <rex-bc.chen@mediatek.com>]

On Tue, 2022-06-21 at 11:33 +0800, CK Hu wrote:
> Hi, Bo-Chen:
> 
> On Mon, 2022-06-20 at 20:10 +0800, Bo-Chen Chen wrote:
> > From: Guillaume Ranquet <granquet@baylibre.com>
> > 
> > Matrix selection is a new feature for both dpi and dpintf of
> > MT8195.
> > Add a mtk_dpi_matrix_sel() helper to update the DPI_MATRIX_SET
> > register depending on the color format.
> 
> Describe more about what this do.
> 

this feature is color format transfer.
For mt8195, the input format is RGB888 andd output format could be
YUV422. do you think I should squash this patch into [v12,12/14]
drm/mediatek: dpi: Add YUV422 output support?

> > 
> > Signed-off-by: Guillaume Ranquet <granquet@baylibre.com>
> > Signed-off-by: Bo-Chen Chen <rex-bc.chen@mediatek.com>
> > ---
> >  drivers/gpu/drm/mediatek/mtk_dpi.c      | 29
> > +++++++++++++++++++++++++
> >  drivers/gpu/drm/mediatek/mtk_dpi_regs.h |  3 +++
> >  2 files changed, 32 insertions(+)
> > 
> > diff --git a/drivers/gpu/drm/mediatek/mtk_dpi.c
> > b/drivers/gpu/drm/mediatek/mtk_dpi.c
> > index 220e9b18e2cd..8a9151cb1622 100644
> > --- a/drivers/gpu/drm/mediatek/mtk_dpi.c
> > +++ b/drivers/gpu/drm/mediatek/mtk_dpi.c
> > @@ -135,6 +135,7 @@ struct mtk_dpi_conf {
> >  	u32 channel_swap_shift;
> >  	u32 yuv422_en_bit;
> >  	u32 csc_enable_bit;
> > +	bool matrx_sel_support;
> >  };
> >  
> >  static void mtk_dpi_mask(struct mtk_dpi *dpi, u32 offset, u32 val,
> > u32 mask)
> > @@ -398,6 +399,31 @@ static void mtk_dpi_config_disable_edge(struct
> > mtk_dpi *dpi)
> >  		mtk_dpi_mask(dpi, dpi->conf->reg_h_fre_con, 0,
> > EDGE_SEL_EN);
> >  }
> >  
> > +static void mtk_dpi_matrix_sel(struct mtk_dpi *dpi,
> > +			       enum mtk_dpi_out_color_format format)
> > +{
> > +	u32 matrix_sel = 0;
> > +
> > +	if (!dpi->conf->matrx_sel_support) {
> > +		dev_info(dpi->dev, "matrix_sel is not supported.\n");
> 
> So for this SoC, there would be something wrong? I still does not
> understand what this feature is.
> 
> static const struct of_device_id mtk_dpi_of_ids[] = {
> 	{ .compatible = "mediatek,mt2701-dpi",
> 	  .data = &mt2701_conf,
> 	},
> 	{ .compatible = "mediatek,mt8173-dpi",
> 	  .data = &mt8173_conf,
> 	},
> 	{ .compatible = "mediatek,mt8183-dpi",
> 	  .data = &mt8183_conf,
> 	},
> 	{ .compatible = "mediatek,mt8192-dpi",
> 	  .data = &mt8192_conf,
> 	},
> 	{ },
> };
> 
> > +		return;
> > +	}
> > +
> > +	switch (format) {
> > +	case MTK_DPI_COLOR_FORMAT_YCBCR_422:
> > +	case MTK_DPI_COLOR_FORMAT_YCBCR_422_FULL:
> > +	case MTK_DPI_COLOR_FORMAT_YCBCR_444:
> > +	case MTK_DPI_COLOR_FORMAT_YCBCR_444_FULL:
> > +	case MTK_DPI_COLOR_FORMAT_XV_YCC:
> > +		if (dpi->mode.hdisplay <= 720)
> > +			matrix_sel = 0x2;
> 
> Symbolize 0x2.
> 
> > +		break;
> > +	default:
> 
> If format is MTK_DPI_COLOR_FORMAT_YCBCR_422 first, then format change
> to MTK_DPI_COLOR_FORMAT_RGB and matrix_sel would still be 0x2. Is
> this
> correct?
> 
> Regards,
> CK
> 
> > +		break;
> > +	}
> > +	mtk_dpi_mask(dpi, DPI_MATRIX_SET, matrix_sel,
> > INT_MATRIX_SEL_MASK);
> > +}
> > +
> >  static void mtk_dpi_config_color_format(struct mtk_dpi *dpi,
> >  					enum mtk_dpi_out_color_format
> > format)
> >  {
> > @@ -405,6 +431,7 @@ static void mtk_dpi_config_color_format(struct
> > mtk_dpi *dpi,
> >  	    (format == MTK_DPI_COLOR_FORMAT_YCBCR_444_FULL)) {
> >  		mtk_dpi_config_yuv422_enable(dpi, false);
> >  		mtk_dpi_config_csc_enable(dpi, true);
> > +		mtk_dpi_matrix_sel(dpi, format);
> >  		if (dpi->conf->swap_input_support)
> >  			mtk_dpi_config_swap_input(dpi, false);
> >  		mtk_dpi_config_channel_swap(dpi,
> > MTK_DPI_OUT_CHANNEL_SWAP_BGR);
> > @@ -412,6 +439,7 @@ static void mtk_dpi_config_color_format(struct
> > mtk_dpi *dpi,
> >  		   (format == MTK_DPI_COLOR_FORMAT_YCBCR_422_FULL)) {
> >  		mtk_dpi_config_yuv422_enable(dpi, true);
> >  		mtk_dpi_config_csc_enable(dpi, true);
> > +		mtk_dpi_matrix_sel(dpi, format);
> >  		if (dpi->conf->swap_input_support)
> >  			mtk_dpi_config_swap_input(dpi, true);
> >  		else
> > @@ -951,6 +979,7 @@ static const struct mtk_dpi_conf
> > mt8195_dpintf_conf = {
> >  	.channel_swap_shift = DPINTF_CH_SWAP,
> >  	.yuv422_en_bit = DPINTF_YUV422_EN,
> >  	.csc_enable_bit = DPINTF_CSC_ENABLE,
> > +	.matrx_sel_support = true,
> >  };
> >  
> >  static int mtk_dpi_probe(struct platform_device *pdev)
> > diff --git a/drivers/gpu/drm/mediatek/mtk_dpi_regs.h
> > b/drivers/gpu/drm/mediatek/mtk_dpi_regs.h
> > index f7f0272dbd6a..96c117202d0d 100644
> > --- a/drivers/gpu/drm/mediatek/mtk_dpi_regs.h
> > +++ b/drivers/gpu/drm/mediatek/mtk_dpi_regs.h
> > @@ -230,4 +230,7 @@
> >  #define EDGE_SEL_EN			BIT(5)
> >  #define H_FRE_2N			BIT(25)
> >  
> > +#define DPI_MATRIX_SET		0xB4
> > +#define INT_MATRIX_SEL_MASK	(0x1F << 0)
> > +
> >  #endif /* __MTK_DPI_REGS_H */
> 
>