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@xxxxxxxxxxxx/ > > Signed-off-by: Liankun Yang <liankun.yang@xxxxxxxxxxxx> > --- > 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_PHYD BIT(0) > > +#define MTK_DP_PHY_DIG_GLB_DA_REG_14 (PHY_OFFSET + 0xD8) > +#define XTP_GLB_TXPLL_SSC_DELTA_RBR_DEFAULT GENMASK(15, 0) > +#define XTP_GLB_TXPLL_SSC_DELTA_HBR_DEFAULT GENMASK(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
