[PATCH v6 4/9] phy: rockchip-samsung-dcphy: Always write the rate-dependent registers

From: Jason Yang

Date: Tue Nov 10 2026 - 03:20:05 EST


The lane timing init functions write DPHY_MC_ANA_CON1, the four data
lane ANA_CON1 registers and DPHY_MC_DESKEW_CON0 only above a data
rate threshold, and the registers have to be zero below it [1].

Today the APB reset at the start of every power_on provides the zero.

A later change moves that reset to runtime resume, so a power_on at a
lower rate after a higher one would keep the old values.

Write the registers on every power_on, with zero below the threshold.

[1] RK3588 TRM: sections 22.4.2 (reset values) and 22.4.3
(DPHY_MC_ANA_CON1, DPHY_MC_DESKEW_CON0)

Signed-off-by: Jason Yang <jason98166@xxxxxxxxx>
---
drivers/phy/rockchip/phy-rockchip-samsung-dcphy.c | 24 +++++++++++++++--------
1 file changed, 16 insertions(+), 8 deletions(-)

diff --git a/drivers/phy/rockchip/phy-rockchip-samsung-dcphy.c b/drivers/phy/rockchip/phy-rockchip-samsung-dcphy.c
index ce1bc62497c5..7a009d87a665 100644
--- a/drivers/phy/rockchip/phy-rockchip-samsung-dcphy.c
+++ b/drivers/phy/rockchip/phy-rockchip-samsung-dcphy.c
@@ -1228,7 +1228,10 @@ samsung_mipi_dphy_clk_lane_timing_init(struct samsung_mipi_dcphy *samsung)
regmap_write(samsung->regmap, DPHY_MC_ANA_CON0, val);

if (lane_hs_rate >= 4500)
- regmap_write(samsung->regmap, DPHY_MC_ANA_CON1, 0x0001);
+ val = 0x0001;
+ else
+ val = 0;
+ regmap_write(samsung->regmap, DPHY_MC_ANA_CON1, val);

val = 0;
/*
@@ -1259,7 +1262,10 @@ samsung_mipi_dphy_clk_lane_timing_init(struct samsung_mipi_dcphy *samsung)
* under 1.5Gbps or equal to 1.5Gbps.
*/
if (lane_hs_rate > 1500)
- regmap_write(samsung->regmap, DPHY_MC_DESKEW_CON0, 0x9cb1);
+ val = 0x9cb1;
+ else
+ val = 0;
+ regmap_write(samsung->regmap, DPHY_MC_DESKEW_CON0, val);
}

static void
@@ -1284,12 +1290,14 @@ samsung_mipi_dphy_data_lane_timing_init(struct samsung_mipi_dcphy *samsung)
regmap_write(samsung->regmap, COMBO_MD2_ANA_CON0, val);
regmap_write(samsung->regmap, DPHY_MD3_ANA_CON0, val);

- if (lane_hs_rate >= 4500) {
- regmap_write(samsung->regmap, COMBO_MD0_ANA_CON1, 0x0001);
- regmap_write(samsung->regmap, COMBO_MD1_ANA_CON1, 0x0001);
- regmap_write(samsung->regmap, COMBO_MD2_ANA_CON1, 0x0001);
- regmap_write(samsung->regmap, DPHY_MD3_ANA_CON1, 0x0001);
- }
+ if (lane_hs_rate >= 4500)
+ val = 0x0001;
+ else
+ val = 0;
+ regmap_write(samsung->regmap, COMBO_MD0_ANA_CON1, val);
+ regmap_write(samsung->regmap, COMBO_MD1_ANA_CON1, val);
+ regmap_write(samsung->regmap, COMBO_MD2_ANA_CON1, val);
+ regmap_write(samsung->regmap, DPHY_MD3_ANA_CON1, val);

val = 0;
/*

--
2.43.0