Re: [PATCH v2 2/3] drm/mediatek: enhance the HDMI driving current

[Bibby Hsieh]

Hi, Philipp,

Thanks for your review.

On Wed, 2016-07-27 at 11:25 +0200, Philipp Zabel wrote:
> Am Mittwoch, den 27.07.2016, 16:31 +0800 schrieb Bibby Hsieh:
> > From: Junzhi Zhao <junzhi.zhao@xxxxxxxxxxxx>
> > 
> > In order to improve 4K resolution performance,
> > we have to enhance the HDMI driving currend
>                                            ^
> Typo, s/currend/current/
> 
> Besides that, this patch looks good to me.
> 
Ok, I will fix that, thanks.
> regards
> Philipp
> 
> > when clock rate is greater than 165MHz.
> > 
> > Signed-off-by: Junzhi Zhao <junzhi.zhao@xxxxxxxxxxxx>
> > Signed-off-by: Bibby Hsieh <bibby.hsieh@xxxxxxxxxxxx>
> > ---
> >  drivers/gpu/drm/mediatek/mtk_mt8173_hdmi_phy.c |   42 +++++++++++++++++-------
> >  1 file changed, 30 insertions(+), 12 deletions(-)
> > 
> > diff --git a/drivers/gpu/drm/mediatek/mtk_mt8173_hdmi_phy.c b/drivers/gpu/drm/mediatek/mtk_mt8173_hdmi_phy.c
> > index 8a24754..51cb9cf 100644
> > --- a/drivers/gpu/drm/mediatek/mtk_mt8173_hdmi_phy.c
> > +++ b/drivers/gpu/drm/mediatek/mtk_mt8173_hdmi_phy.c
> > @@ -265,6 +265,9 @@ static int mtk_hdmi_pll_set_rate(struct clk_hw *hw, unsigned long rate,
> >  	struct mtk_hdmi_phy *hdmi_phy = to_mtk_hdmi_phy(hw);
> >  	unsigned int pre_div;
> >  	unsigned int div;
> > +	unsigned int pre_ibias;
> > +	unsigned int hdmi_ibias;
> > +	unsigned int imp_en;
> >  
> >  	dev_dbg(hdmi_phy->dev, "%s: %lu Hz, parent: %lu Hz\n", __func__,
> >  		rate, parent_rate);
> > @@ -298,18 +301,31 @@ static int mtk_hdmi_pll_set_rate(struct clk_hw *hw, unsigned long rate,
> >  			  (0x1 << PLL_BR_SHIFT),
> >  			  RG_HDMITX_PLL_BP | RG_HDMITX_PLL_BC |
> >  			  RG_HDMITX_PLL_BR);
> > -	mtk_hdmi_phy_clear_bits(hdmi_phy, HDMI_CON3, RG_HDMITX_PRD_IMP_EN);
> > +	if (rate < 165000000) {
> > +		mtk_hdmi_phy_clear_bits(hdmi_phy, HDMI_CON3,
> > +					RG_HDMITX_PRD_IMP_EN);
> > +		pre_ibias = 0x3;
> > +		imp_en = 0x0;
> > +		hdmi_ibias = hdmi_phy->ibias;
> > +	} else {
> > +		mtk_hdmi_phy_set_bits(hdmi_phy, HDMI_CON3,
> > +				      RG_HDMITX_PRD_IMP_EN);
> > +		pre_ibias = 0x6;
> > +		imp_en = 0xf;
> > +		hdmi_ibias = hdmi_phy->ibias_up;
> > +	}
> >  	mtk_hdmi_phy_mask(hdmi_phy, HDMI_CON4,
> > -			  (0x3 << PRD_IBIAS_CLK_SHIFT) |
> > -			  (0x3 << PRD_IBIAS_D2_SHIFT) |
> > -			  (0x3 << PRD_IBIAS_D1_SHIFT) |
> > -			  (0x3 << PRD_IBIAS_D0_SHIFT),
> > +			  (pre_ibias << PRD_IBIAS_CLK_SHIFT) |
> > +			  (pre_ibias << PRD_IBIAS_D2_SHIFT) |
> > +			  (pre_ibias << PRD_IBIAS_D1_SHIFT) |
> > +			  (pre_ibias << PRD_IBIAS_D0_SHIFT),
> >  			  RG_HDMITX_PRD_IBIAS_CLK |
> >  			  RG_HDMITX_PRD_IBIAS_D2 |
> >  			  RG_HDMITX_PRD_IBIAS_D1 |
> >  			  RG_HDMITX_PRD_IBIAS_D0);
> >  	mtk_hdmi_phy_mask(hdmi_phy, HDMI_CON3,
> > -			  (0x0 << DRV_IMP_EN_SHIFT), RG_HDMITX_DRV_IMP_EN);
> > +			  (imp_en << DRV_IMP_EN_SHIFT),
> > +			  RG_HDMITX_DRV_IMP_EN);
> >  	mtk_hdmi_phy_mask(hdmi_phy, HDMI_CON6,
> >  			  (hdmi_phy->drv_imp_clk << DRV_IMP_CLK_SHIFT) |
> >  			  (hdmi_phy->drv_imp_d2 << DRV_IMP_D2_SHIFT) |
> > @@ -318,12 +334,14 @@ static int mtk_hdmi_pll_set_rate(struct clk_hw *hw, unsigned long rate,
> >  			  RG_HDMITX_DRV_IMP_CLK | RG_HDMITX_DRV_IMP_D2 |
> >  			  RG_HDMITX_DRV_IMP_D1 | RG_HDMITX_DRV_IMP_D0);
> >  	mtk_hdmi_phy_mask(hdmi_phy, HDMI_CON5,
> > -			  (hdmi_phy->ibias << DRV_IBIAS_CLK_SHIFT) |
> > -			  (hdmi_phy->ibias << DRV_IBIAS_D2_SHIFT) |
> > -			  (hdmi_phy->ibias << DRV_IBIAS_D1_SHIFT) |
> > -			  (hdmi_phy->ibias << DRV_IBIAS_D0_SHIFT),
> > -			  RG_HDMITX_DRV_IBIAS_CLK | RG_HDMITX_DRV_IBIAS_D2 |
> > -			  RG_HDMITX_DRV_IBIAS_D1 | RG_HDMITX_DRV_IBIAS_D0);
> > +			  (hdmi_ibias << DRV_IBIAS_CLK_SHIFT) |
> > +			  (hdmi_ibias << DRV_IBIAS_D2_SHIFT) |
> > +			  (hdmi_ibias << DRV_IBIAS_D1_SHIFT) |
> > +			  (hdmi_ibias << DRV_IBIAS_D0_SHIFT),
> > +			  RG_HDMITX_DRV_IBIAS_CLK |
> > +			  RG_HDMITX_DRV_IBIAS_D2 |
> > +			  RG_HDMITX_DRV_IBIAS_D1 |
> > +			  RG_HDMITX_DRV_IBIAS_D0);
> >  	return 0;
> >  }
> >  
> 
> 

-- 
Bibby