[PATCH v2 1/2] Add write DP phyd register from parse dts

LIANKUN YANG (杨连坤) Liankun.Yang at mediatek.com
Mon May 13 07:21:41 PDT 2024


On Mon, 2024-05-13 at 08:38 +0200, Krzysztof Kozlowski wrote:
>  	 
> External email : Please do not click links or open attachments until
> you have verified the sender or the content.
>  On 10/05/2024 13:04, Liankun Yang wrote:
> > During the testing phase, screen flickering is observed when
> > using displayport for screen casting. Relevant SSC register
> parameters
> > are set in dts to address the screen flickering issue effectively
> and
> > improve compatibility with different devices by adjusting the SSC
> gear.
> > 
> > Obtaining the DPTX node, parsing the dts to obtain PHY register
> address
> > and value can adapt to settings of different manufacturers
> projects.
> > 
> > Changeds in v2:
> > - Optimized method of writing to DP PHY register
> > https://patchwork.kernel.org/project/linux-mediatek/patch/
> > 20240403040517.3279-1-liankun.yang at mediatek.com/
> > 
> > Signed-off-by: Liankun Yang <liankun.yang at mediatek.com>
> > ---
> >  drivers/phy/mediatek/phy-mtk-dp.c | 37
> +++++++++++++++++++++++++++++++
> >  1 file changed, 37 insertions(+)
> > 
> > diff --git a/drivers/phy/mediatek/phy-mtk-dp.c
> b/drivers/phy/mediatek/phy-mtk-dp.c
> > index d7024a144335..ce78112d5938 100644
> > --- a/drivers/phy/mediatek/phy-mtk-dp.c
> > +++ b/drivers/phy/mediatek/phy-mtk-dp.c
> > @@ -28,6 +28,10 @@
> >  #define MTK_DP_PHY_DIG_SW_RST(PHY_OFFSET + 0x38)
> >  #define DP_GLB_SW_RST_PHYDBIT(0)
> >  
> > +#define MTK_DP_PHY_DIG_GLB_DA_REG_14(PHY_OFFSET + 0xD8)
> > +#define XTP_GLB_TXPLL_SSC_DELTA_RBR_DEFAULTGENMASK(15, 0)
> > +#define XTP_GLB_TXPLL_SSC_DELTA_HBR_DEFAULTGENMASK(31, 16)
> > +
> >  #define MTK_DP_LANE0_DRIVING_PARAM_3(PHY_OFFSET + 0x138)
> >  #define MTK_DP_LANE1_DRIVING_PARAM_3(PHY_OFFSET + 0x238)
> >  #define MTK_DP_LANE2_DRIVING_PARAM_3(PHY_OFFSET + 0x338)
> > @@ -78,10 +82,39 @@
> >  #define DRIVING_PARAM_8_DEFAULT(XTP_LN_TX_LCTXCP1_SW2_PRE1_DEFAULT
> | \
> >   XTP_LN_TX_LCTXCP1_SW3_PRE0_DEFAULT)
> >  
> > +#define SSC_SETTING"dp-ssc-setting"
> > +#define RG_XTP_GLB_TXPLL_SSC_DELTA_HBR"ssc-delta-hbr"
> > +
> >  struct mtk_dp_phy {
> >  struct regmap *regs;
> > +struct device *dev;
> >  };
> >  
> > +static int mtk_dp_set_ssc_config(struct phy *phy, struct
> mtk_dp_phy *dp_phy)
> > +{
> > +int ret;
> > +u32 read_value = 0, reg_mask = 0;
> > +struct device_node *ssc_node = NULL;
> > +
> > +ssc_node = of_find_node_by_name(dp_phy->dev->of_node,
> SSC_SETTING);
> 
> No, really. Node name can change.
> 
> Best regards,
> Krzysztof
> 

Thank you for your comment.
I will change the node name.

Best regards.
Liankun yang


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