[PATCH v3 1/6] phy: allwinner: phy-sun6i-mipi-dphy: Support LVDS in combo D-PHY

Kuba Szczodrzyński posted 6 patches 1 month ago
[PATCH v3 1/6] phy: allwinner: phy-sun6i-mipi-dphy: Support LVDS in combo D-PHY
Posted by Kuba Szczodrzyński 1 month ago
Some Allwinner chips (notably the D1s/T113 and the A100) have a "combo
MIPI DSI D-PHY" which is required when using single-link LVDS0.

In this mode, the DSI peripheral is not used and the PHY is not
configured for DSI. Instead, the COMBO_PHY_REGx registers are set to
enable LVDS operation.

Enable the PHY driver to work in LVDS mode on chips with a combo D-PHY.

Also change the SUN50I_COMBO_PHY_REG1 macro names to reflect the correct
register name.

Signed-off-by: Kuba Szczodrzyński <kuba@szczodrzynski.pl>
---
 drivers/phy/allwinner/phy-sun6i-mipi-dphy.c | 70 ++++++++++++++++++++-
 1 file changed, 68 insertions(+), 2 deletions(-)

diff --git a/drivers/phy/allwinner/phy-sun6i-mipi-dphy.c b/drivers/phy/allwinner/phy-sun6i-mipi-dphy.c
index 36eab9527..57035b3a4 100644
--- a/drivers/phy/allwinner/phy-sun6i-mipi-dphy.c
+++ b/drivers/phy/allwinner/phy-sun6i-mipi-dphy.c
@@ -166,8 +166,8 @@
 #define SUN50I_COMBO_PHY_REG0_EN_CP		BIT(0)
 
 #define SUN50I_COMBO_PHY_REG1		0x114
-#define SUN50I_COMBO_PHY_REG2_REG_VREF1P6(n)	(((n) & 0x7) << 4)
-#define SUN50I_COMBO_PHY_REG2_REG_VREF0P8(n)	((n) & 0x7)
+#define SUN50I_COMBO_PHY_REG1_REG_VREF1P6(n)	(((n) & 0x7) << 4)
+#define SUN50I_COMBO_PHY_REG1_REG_VREF0P8(n)	((n) & 0x7)
 
 #define SUN50I_COMBO_PHY_REG2		0x118
 #define SUN50I_COMBO_PHY_REG2_HS_STOP_DLY(n)	((n) & 0xff)
@@ -181,7 +181,9 @@ struct sun6i_dphy;
 
 struct sun6i_dphy_variant {
 	void	(*tx_power_on)(struct sun6i_dphy *dphy);
+	void	(*lvds_power_on)(struct sun6i_dphy *dphy);
 	bool	rx_supported;
+	bool	is_combo_dphy;
 };
 
 struct sun6i_dphy {
@@ -222,6 +224,18 @@ static int sun6i_dphy_configure(struct phy *phy, union phy_configure_opts *opts)
 	return 0;
 }
 
+static int sun6i_dphy_set_mode(struct phy *phy, enum phy_mode mode, int submode)
+{
+	struct sun6i_dphy *dphy = phy_get_drvdata(phy);
+
+	if (mode == PHY_MODE_LVDS && !dphy->variant->is_combo_dphy) {
+		/* Not a combo D-PHY: LVDS is not supported. */
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
 static void sun6i_a31_mipi_dphy_tx_power_on(struct sun6i_dphy *dphy)
 {
 	u8 lanes_mask = GENMASK(dphy->config.lanes - 1, 0);
@@ -329,6 +343,43 @@ static void sun50i_a100_mipi_dphy_tx_power_on(struct sun6i_dphy *dphy)
 	udelay(1);
 }
 
+static void sun50i_a100_mipi_dphy_lvds_power_on(struct sun6i_dphy *dphy)
+{
+	regmap_write(dphy->regs, SUN50I_COMBO_PHY_REG1,
+		     SUN50I_COMBO_PHY_REG1_REG_VREF1P6(4) |
+		     SUN50I_COMBO_PHY_REG1_REG_VREF0P8(3));
+
+	regmap_write(dphy->regs, SUN50I_COMBO_PHY_REG0,
+		     SUN50I_COMBO_PHY_REG0_EN_CP);
+	udelay(5);
+
+	regmap_update_bits(dphy->regs, SUN50I_COMBO_PHY_REG0,
+			   SUN50I_COMBO_PHY_REG0_EN_LVDS,
+			   SUN50I_COMBO_PHY_REG0_EN_LVDS);
+	udelay(5);
+
+	regmap_update_bits(dphy->regs, SUN50I_COMBO_PHY_REG0,
+			   SUN50I_COMBO_PHY_REG0_EN_COMBOLDO,
+			   SUN50I_COMBO_PHY_REG0_EN_COMBOLDO);
+	udelay(5);
+
+	regmap_update_bits(dphy->regs, SUN50I_COMBO_PHY_REG0,
+			   SUN50I_COMBO_PHY_REG0_EN_MIPI,
+			   SUN50I_COMBO_PHY_REG0_EN_MIPI);
+
+	regmap_write(dphy->regs, SUN6I_DPHY_ANA4_REG,
+		     SUN6I_DPHY_ANA4_REG_EN_MIPI |
+		     SUN6I_DPHY_ANA4_REG_IB(2));
+
+	regmap_write(dphy->regs, SUN6I_DPHY_ANA3_REG,
+		     SUN6I_DPHY_ANA3_EN_LDOR |
+		     SUN6I_DPHY_ANA3_EN_LDOD);
+
+	regmap_write(dphy->regs, SUN6I_DPHY_ANA2_REG, 0);
+
+	regmap_write(dphy->regs, SUN6I_DPHY_ANA1_REG, 0);
+}
+
 static int sun6i_dphy_tx_power_on(struct sun6i_dphy *dphy)
 {
 	u8 lanes_mask = GENMASK(dphy->config.lanes - 1, 0);
@@ -492,6 +543,13 @@ static int sun6i_dphy_power_on(struct phy *phy)
 {
 	struct sun6i_dphy *dphy = phy_get_drvdata(phy);
 
+	if (phy->attrs.mode == PHY_MODE_LVDS && dphy->variant->is_combo_dphy) {
+		if (!dphy->variant->lvds_power_on)
+			return -EINVAL;
+		dphy->variant->lvds_power_on(dphy);
+		return 0;
+	}
+
 	switch (dphy->direction) {
 	case SUN6I_DPHY_DIRECTION_TX:
 		return sun6i_dphy_tx_power_on(dphy);
@@ -514,6 +572,11 @@ static int sun6i_dphy_power_off(struct phy *phy)
 	regmap_write(dphy->regs, SUN6I_DPHY_ANA3_REG, 0);
 	regmap_write(dphy->regs, SUN6I_DPHY_ANA4_REG, 0);
 
+	if (phy->attrs.mode == PHY_MODE_LVDS && dphy->variant->is_combo_dphy) {
+		regmap_write(dphy->regs, SUN50I_COMBO_PHY_REG1, 0);
+		regmap_write(dphy->regs, SUN50I_COMBO_PHY_REG0, 0);
+	}
+
 	return 0;
 }
 
@@ -533,6 +596,7 @@ static const struct phy_ops sun6i_dphy_ops = {
 	.configure	= sun6i_dphy_configure,
 	.power_on	= sun6i_dphy_power_on,
 	.power_off	= sun6i_dphy_power_off,
+	.set_mode	= sun6i_dphy_set_mode,
 	.init		= sun6i_dphy_init,
 	.exit		= sun6i_dphy_exit,
 };
@@ -619,6 +683,8 @@ static const struct sun6i_dphy_variant sun6i_a31_mipi_dphy_variant = {
 
 static const struct sun6i_dphy_variant sun50i_a100_mipi_dphy_variant = {
 	.tx_power_on	= sun50i_a100_mipi_dphy_tx_power_on,
+	.lvds_power_on	= sun50i_a100_mipi_dphy_lvds_power_on,
+	.is_combo_dphy	= true,
 };
 
 static const struct of_device_id sun6i_dphy_of_table[] = {
-- 
2.25.1

Re: [PATCH v3 1/6] phy: allwinner: phy-sun6i-mipi-dphy: Support LVDS in combo D-PHY
Posted by Parthiban 3 weeks, 5 days ago
Dear Kuba,

Thanks for your efforts.

On 11/16/25 2:47 PM, Kuba Szczodrzyński wrote:
> Some Allwinner chips (notably the D1s/T113 and the A100) have a "combo
> MIPI DSI D-PHY" which is required when using single-link LVDS0.
> 
> In this mode, the DSI peripheral is not used and the PHY is not
> configured for DSI. Instead, the COMBO_PHY_REGx registers are set to
> enable LVDS operation.
> 
> Enable the PHY driver to work in LVDS mode on chips with a combo D-PHY.
> 
> Also change the SUN50I_COMBO_PHY_REG1 macro names to reflect the correct
> register name.
> 
> Signed-off-by: Kuba Szczodrzyński <kuba@szczodrzynski.pl>
> ---
>  drivers/phy/allwinner/phy-sun6i-mipi-dphy.c | 70 ++++++++++++++++++++-
>  1 file changed, 68 insertions(+), 2 deletions(-)

I tried integrating your changes in A133 display pipeline and I couldn't get the LVDS working.
Am still narrowing down what is missing in your patch. Driver registration is success and I
can see /dev/fb0 as well. But nothing on the display itself.

But with below changes from my patch,

diff --git a/drivers/phy/allwinner/phy-sun6i-mipi-dphy.c b/drivers/phy/allwinner/phy-sun6i-mipi-dphy.c
index 36eab95271b2..d164b2ea5dfd 100644
--- a/drivers/phy/allwinner/phy-sun6i-mipi-dphy.c
+++ b/drivers/phy/allwinner/phy-sun6i-mipi-dphy.c
@@ -314,13 +314,11 @@ static void sun50i_a100_mipi_dphy_tx_power_on(struct sun6i_dphy *dphy)
        /* Disable sigma-delta modulation. */
        regmap_write(dphy->regs, SUN50I_DPHY_PLL_REG2, 0);
 
-       regmap_update_bits(dphy->regs, SUN6I_DPHY_ANA4_REG,
-                          SUN6I_DPHY_ANA4_REG_EN_MIPI,
-                          SUN6I_DPHY_ANA4_REG_EN_MIPI);
-
        regmap_update_bits(dphy->regs, SUN50I_COMBO_PHY_REG0,
+                          SUN50I_COMBO_PHY_REG0_EN_LVDS |
                           SUN50I_COMBO_PHY_REG0_EN_MIPI |
                           SUN50I_COMBO_PHY_REG0_EN_COMBOLDO,
+                          SUN50I_COMBO_PHY_REG0_EN_LVDS |
                           SUN50I_COMBO_PHY_REG0_EN_MIPI |
                           SUN50I_COMBO_PHY_REG0_EN_COMBOLDO);
 
@@ -528,6 +526,22 @@ static int sun6i_dphy_exit(struct phy *phy)
        return 0;
 }

LVDS works fine.

Could you please share the diff of your dts / dtsi?

Thanks,
Parthiban
Re: [PATCH v3 1/6] phy: allwinner: phy-sun6i-mipi-dphy: Support LVDS in combo D-PHY
Posted by Kuba Szczodrzyński 3 weeks, 3 days ago
W dniu 2025-11-20 o 07:24:53, Parthiban pisze:

> Dear Kuba,
>
> Thanks for your efforts.
>
> On 11/16/25 2:47 PM, Kuba Szczodrzyński wrote:
>> Some Allwinner chips (notably the D1s/T113 and the A100) have a "combo
>> MIPI DSI D-PHY" which is required when using single-link LVDS0.
>>
>> In this mode, the DSI peripheral is not used and the PHY is not
>> configured for DSI. Instead, the COMBO_PHY_REGx registers are set to
>> enable LVDS operation.
>>
>> Enable the PHY driver to work in LVDS mode on chips with a combo D-PHY.
>>
>> Also change the SUN50I_COMBO_PHY_REG1 macro names to reflect the correct
>> register name.
>>
>> Signed-off-by: Kuba Szczodrzyński <kuba@szczodrzynski.pl>
>> ---
>>   drivers/phy/allwinner/phy-sun6i-mipi-dphy.c | 70 ++++++++++++++++++++-
>>   1 file changed, 68 insertions(+), 2 deletions(-)
> I tried integrating your changes in A133 display pipeline and I couldn't get the LVDS working.
> Am still narrowing down what is missing in your patch. Driver registration is success and I
> can see /dev/fb0 as well. But nothing on the display itself.
>
> But with below changes from my patch,
>
> diff --git a/drivers/phy/allwinner/phy-sun6i-mipi-dphy.c b/drivers/phy/allwinner/phy-sun6i-mipi-dphy.c
> index 36eab95271b2..d164b2ea5dfd 100644
> --- a/drivers/phy/allwinner/phy-sun6i-mipi-dphy.c
> +++ b/drivers/phy/allwinner/phy-sun6i-mipi-dphy.c
> @@ -314,13 +314,11 @@ static void sun50i_a100_mipi_dphy_tx_power_on(struct sun6i_dphy *dphy)
>          /* Disable sigma-delta modulation. */
>          regmap_write(dphy->regs, SUN50I_DPHY_PLL_REG2, 0);
>   
> -       regmap_update_bits(dphy->regs, SUN6I_DPHY_ANA4_REG,
> -                          SUN6I_DPHY_ANA4_REG_EN_MIPI,
> -                          SUN6I_DPHY_ANA4_REG_EN_MIPI);
> -
>          regmap_update_bits(dphy->regs, SUN50I_COMBO_PHY_REG0,
> +                          SUN50I_COMBO_PHY_REG0_EN_LVDS |
>                             SUN50I_COMBO_PHY_REG0_EN_MIPI |
>                             SUN50I_COMBO_PHY_REG0_EN_COMBOLDO,
> +                          SUN50I_COMBO_PHY_REG0_EN_LVDS |
>                             SUN50I_COMBO_PHY_REG0_EN_MIPI |
>                             SUN50I_COMBO_PHY_REG0_EN_COMBOLDO);
>   
> @@ -528,6 +526,22 @@ static int sun6i_dphy_exit(struct phy *phy)
>          return 0;
>   }
>
> LVDS works fine.
>
> Could you please share the diff of your dts / dtsi?

Hi,
Here's the DTS overlay I used to enable an LVDS panel on T113. You'll need to adapt the panel specification to your particular display.
I did not need to change the phy driver, so this extra requirement might be specific to A133.

/dts-v1/;
/plugin/;

&{/} {
	panel {
		compatible = "panel-lvds";
		data-mapping = "jeida-18";
		ddc-i2c-bus = <&i2c2>;

		port {
			panel_input: endpoint {
				remote-endpoint = <&tcon_lcd0_out_lvds>;
			};
		};
	};
};

&tcon_lcd0 {
	pinctrl-names = "default";
	pinctrl-0 = <&lcd_lvds0_pins>;
};

&tcon_lcd0_out {
	reg = <1>;
	#address-cells = <1>;
	#size-cells = <0>;

	tcon_lcd0_out_lvds: endpoint@0 {
		reg = <0>;
		remote-endpoint = <&panel_input>;
	};
};

Regards
Kuba

>
> Thanks,
> Parthiban