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

From: CK Hu <ck.hu@mediatek.com>
To: Rex-BC Chen <rex-bc.chen@mediatek.com>, <chunkuang.hu@kernel.org>,
	<p.zabel@pengutronix.de>, <daniel@ffwll.ch>, <robh+dt@kernel.org>,
	<krzysztof.kozlowski+dt@linaro.org>, <matthias.bgg@gmail.com>,
	<airlied@linux.ie>
Cc: <msp@baylibre.com>, <granquet@baylibre.com>,
	<jitao.shi@mediatek.com>, <wenst@chromium.org>,
	<angelogioacchino.delregno@collabora.com>,
	<dri-devel@lists.freedesktop.org>,
	<linux-mediatek@lists.infradead.org>,
	<devicetree@vger.kernel.org>, <linux-kernel@vger.kernel.org>,
	<linux-arm-kernel@lists.infradead.org>,
	<Project_Global_Chrome_Upstream_Group@mediatek.com>
Subject: Re: [PATCH v12 14/14] drm/mediatek: dpi: Add matrix_sel helper
Date: Tue, 21 Jun 2022 17:12:34 +0800	[thread overview]
Message-ID: <59a4bdf0800afc445f223d07aac8b5335d6e36e8.camel@mediatek.com> (raw)
In-Reply-To: <5907e3fc6a690bb79c2ad9b20f6e353b2ba8c774.camel@mediatek.com>

Hi, Rex:

On Tue, 2022-06-21 at 16:41 +0800, Rex-BC Chen wrote:
> 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?

OK, squash these two patches and add this description into commit
message. For RGB input and RGB output, I think this function should be
disabled.

Regards,
CK

> 
> > > 
> > > 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 */
> > 
> > 
> 
> 