Re: [PATCH v12 10/14] drm/mediatek: dpi: Add dpintf support

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

On Tue, 2022-06-21 at 10:32 +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>
> > 
> > dpintf is the displayport interface hardware unit. This unit is
> > similar
> > to dpi and can reuse most of the code.
> > 
> > This patch adds support for mt8195-dpintf to this dpi driver. Main
> > differences are:
> >  - 4 pixels for one round for dp_intf while dpi is 1 pixel for one
> > round.
> >    Therefore, pixel clock and timing parameter should be divided by
> > 4
> > for
> >    dp_intf.
> >  - Some features/functional components are not available for dpintf
> >    which are now excluded from code execution once is_dpintf is
> > set.
> >    The main difference is some parts of hardware design between
> > dp_intf
> >    and dpi.
> >  - Some register contents differ slightly between the two
> > components.
> > To
> >    work around this I added register bits/masks with a DPINTF_
> > prefix
> >    and use them where different.
> > 
> > Based on a separate driver for dpintf created by
> > Jitao shi <jitao.shi@mediatek.com>.
> > 
> > Signed-off-by: Markus Schneider-Pargmann <msp@baylibre.com>
> > Signed-off-by: Guillaume Ranquet <granquet@baylibre.com>
> > [Bo-Chen: Modify reviewers' comments.]
> > Signed-off-by: Bo-Chen Chen <rex-bc.chen@mediatek.com>
> > ---
> >  drivers/gpu/drm/mediatek/mtk_dpi.c          | 65
> > +++++++++++++++++++--
> >  drivers/gpu/drm/mediatek/mtk_dpi_regs.h     | 13 +++++
> >  drivers/gpu/drm/mediatek/mtk_drm_ddp_comp.c |  4 ++
> >  drivers/gpu/drm/mediatek/mtk_drm_ddp_comp.h |  1 +
> >  drivers/gpu/drm/mediatek/mtk_drm_drv.c      |  3 +
> >  5 files changed, 82 insertions(+), 4 deletions(-)
> > 
> > diff --git a/drivers/gpu/drm/mediatek/mtk_dpi.c
> > b/drivers/gpu/drm/mediatek/mtk_dpi.c
> > index e186870ba3bc..2717b1741b7a 100644
> > --- a/drivers/gpu/drm/mediatek/mtk_dpi.c
> > +++ b/drivers/gpu/drm/mediatek/mtk_dpi.c
> > @@ -126,6 +126,7 @@ struct mtk_dpi_conf {
> >  	const u32 *output_fmts;
> >  	u32 num_output_fmts;
> >  	bool is_ck_de_pol;
> > +	bool is_dpintf;
> >  	bool swap_input_support;
> >  	/* Mask used for HWIDTH, HPORCH, VSYNC_WIDTH and VSYNC_PORCH
> > (no shift) */
> >  	u32 dimension_mask;
> > @@ -513,6 +514,14 @@ static int mtk_dpi_set_display_mode(struct
> > mtk_dpi *dpi,
> >  	pll_rate = clk_get_rate(dpi->tvd_clk);
> >  
> >  	vm.pixelclock = pll_rate / factor;
> > +
> > +	/*
> > +	 * For dp_intf, we need to divide clock by 4 because it's
> > +	 * 4 pixels for one round while dpi is 1 pixel for one round.
> > +	 */
> > +	if (dpi->conf->is_dpintf)
> > +		vm.pixelclock /= 4;
> 
> I this this should define dpi->conf->round_pixels rather than dpi-
> > conf->is_dpintf.

ok, I will use this config and drop is_dpintf.

> > +
> >  	if ((dpi->output_fmt == MEDIA_BUS_FMT_RGB888_2X12_LE) ||
> >  	    (dpi->output_fmt == MEDIA_BUS_FMT_RGB888_2X12_BE))
> >  		clk_set_rate(dpi->pixel_clk, vm.pixelclock * 2);
> > @@ -534,6 +543,17 @@ static int mtk_dpi_set_display_mode(struct
> > mtk_dpi *dpi,
> >  	hsync.sync_width = vm.hsync_len;
> >  	hsync.back_porch = vm.hback_porch;
> >  	hsync.front_porch = vm.hfront_porch;
> > +
> > +	/*
> > +	 * For dp_intf, we need to divide everything by 4 because it's
> > +	 * 4 pixels for one round while dpi is 1 pixel for one round.
> > +	 */
> > +	if (dpi->conf->is_dpintf) {
> > +		hsync.sync_width = vm.hsync_len / 4;
> > +		hsync.back_porch = vm.hback_porch / 4;
> > +		hsync.front_porch = vm.hfront_porch / 4;
> > +	}
> 
> Ditto.
> 
> > +
> >  	hsync.shift_half_line = false;
> >  	vsync_lodd.sync_width = vm.vsync_len;
> >  	vsync_lodd.back_porch = vm.vback_porch;
> > @@ -575,11 +595,16 @@ static int mtk_dpi_set_display_mode(struct
> > mtk_dpi *dpi,
> >  	mtk_dpi_config_channel_limit(dpi);
> >  	mtk_dpi_config_bit_num(dpi, dpi->bit_num);
> >  	mtk_dpi_config_channel_swap(dpi, dpi->channel_swap);
> > -	mtk_dpi_config_yc_map(dpi, dpi->yc_map);
> >  	mtk_dpi_config_color_format(dpi, dpi->color_format);
> > -	mtk_dpi_config_2n_h_fre(dpi);
> > -	mtk_dpi_dual_edge(dpi);
> > -	mtk_dpi_config_disable_edge(dpi);
> > +	if (dpi->conf->is_dpintf) {
> 
> Separate this to an independent patch and give a better config name
> rather than dpi->conf->is_dpintf.
> 

this is separate config.
I will modify like this:
add new config "input_2pixel" for input two pixels in this patch:
mtk_dpi_mask(dpi, DPI_CON, DPINTF_INPUT_2P_EN,
			     DPINTF_INPUT_2P_EN);

and create another patch to add config "support_direct_pin"
this config is only used for dpi which could be directly connect to
pins while dp_intf is not.

+       if (dpi->conf->support_direct_pin) {
+               mtk_dpi_config_yc_map(dpi, dpi->yc_map);
+               mtk_dpi_config_2n_h_fre(dpi);
+               mtk_dpi_dual_edge(dpi);
+               mtk_dpi_config_disable_edge(dpi);
+       }

BRs,
Bo-Chen
> > +		mtk_dpi_mask(dpi, DPI_CON, DPINTF_INPUT_2P_EN,
> > +			     DPINTF_INPUT_2P_EN);
> > +	} else {
> > +		mtk_dpi_config_yc_map(dpi, dpi->yc_map);
> > +		mtk_dpi_config_2n_h_fre(dpi);
> > +		mtk_dpi_dual_edge(dpi);
> > +		mtk_dpi_config_disable_edge(dpi);
> > +	}
> >  	mtk_dpi_sw_reset(dpi, false);
> >  
> >  	return 0;
> > @@ -817,6 +842,16 @@ static unsigned int
> > mt8183_calculate_factor(int
> > clock)
> >  		return 2;
> >  }
> >  
> 
> [snip]
> 
> >  
> >  #define EDGE_SEL_EN			BIT(5)
> >  #define H_FRE_2N			BIT(25)
> > +
> 
> This seems not related to dpintf support.
> 
> Regards,
> CK
> 
> >  #endif /* __MTK_DPI_REGS_H */
> > 
> 
>