[PATCH 0/3] phy: rockchip: inno-csidphy: fix 2500 Mbps support and add clock lane phase tuning

[PATCH 0/3] phy: rockchip: inno-csidphy: fix 2500 Mbps support and add clock lane phase tuning

[Gerald Loacker]

This series fixes and extends the Rockchip Innosilicon CSI D-PHY driver
to support data rates up to 2500 Mbps and adds optional board-specific
clock lane phase tuning for signal integrity.

Patch 1 fixes an off-by-one error in the rk1808 hsfreq range table:
the final entry was capped at 2499 Mbps, causing a rejection of the
maximum supported rate of 2500 Mbps.

Patches 2 and 3 add an optional rockchip,clk-lane-phase device tree
property that allows tuning the clock lane sampling phase in ~40 ps
steps to compensate for board-level signal integrity variations.

---
Gerald Loacker (3):
      phy: rockchip: phy-rockchip-inno-csidphy: fix rk1808 hsfreq table
      dt-bindings: phy: rockchip-inno-csi-dphy: add rockchip,clk-lane-phase property
      phy: rockchip: phy-rockchip-inno-csidphy: add clock lane phase tuning

 .../bindings/phy/rockchip-inno-csi-dphy.yaml       |  7 ++++++
 drivers/phy/rockchip/phy-rockchip-inno-csidphy.c   | 27 +++++++++++++++++++++-
 2 files changed, 33 insertions(+), 1 deletion(-)
---
base-commit: 8cd9520d35a6c38db6567e97dd93b1f11f185dc6
change-id: 20260617-feature-mipi-csi-dphy-4k60-9879c3d1fe4f

Best regards,
--  
Gerald Loacker <gerald.loacker@wolfvision.net>

[PATCH 1/3] phy: rockchip: phy-rockchip-inno-csidphy: fix rk1808 hsfreq table

[Gerald Loacker]

The rk1808 hsfreq table capped at 2499 Mbps, preventing a data rate of
exactly 2500 Mbps. Extend the final entry to 2500 Mbps to support this
rate.

This is essential for RK3588 reusing this array and fully supporting
rates up to 2500 Mbps.

Fixes: bd1f775d6027 ("phy/rockchip: add Innosilicon-based CSI dphy")
Signed-off-by: Gerald Loacker <gerald.loacker@wolfvision.net>
---
 drivers/phy/rockchip/phy-rockchip-inno-csidphy.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/phy/rockchip/phy-rockchip-inno-csidphy.c b/drivers/phy/rockchip/phy-rockchip-inno-csidphy.c
index c79fb53d8ee5c..5281f8dea0ad3 100644
--- a/drivers/phy/rockchip/phy-rockchip-inno-csidphy.c
+++ b/drivers/phy/rockchip/phy-rockchip-inno-csidphy.c
@@ -170,7 +170,7 @@ static const struct hsfreq_range rk1808_mipidphy_hsfreq_ranges[] = {
 	{ 299, 0x06}, { 399, 0x08}, { 499, 0x0b}, { 599, 0x0e},
 	{ 699, 0x10}, { 799, 0x12}, { 999, 0x16}, {1199, 0x1e},
 	{1399, 0x23}, {1599, 0x2d}, {1799, 0x32}, {1999, 0x37},
-	{2199, 0x3c}, {2399, 0x41}, {2499, 0x46}
+	{2199, 0x3c}, {2399, 0x41}, {2500, 0x46}
 };
 
 static const struct hsfreq_range rk3326_mipidphy_hsfreq_ranges[] = {

-- 
2.34.1

[PATCH 2/3] dt-bindings: phy: rockchip-inno-csi-dphy: add rockchip,clk-lane-phase property

[Gerald Loacker]

Add support for the optional rockchip,clk-lane-phase device tree property
to allow board-specific tuning of the clock lane sampling phase for
improved signal integrity across supported data rates.

Signed-off-by: Gerald Loacker <gerald.loacker@wolfvision.net>
---
 Documentation/devicetree/bindings/phy/rockchip-inno-csi-dphy.yaml | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/Documentation/devicetree/bindings/phy/rockchip-inno-csi-dphy.yaml b/Documentation/devicetree/bindings/phy/rockchip-inno-csi-dphy.yaml
index 03950b3cad08c..0d824d1511bc0 100644
--- a/Documentation/devicetree/bindings/phy/rockchip-inno-csi-dphy.yaml
+++ b/Documentation/devicetree/bindings/phy/rockchip-inno-csi-dphy.yaml
@@ -56,6 +56,13 @@ properties:
     description:
       Some additional phy settings are access through GRF regs.
 
+  rockchip,clk-lane-phase:
+    $ref: /schemas/types.yaml#/definitions/uint32
+    minimum: 0
+    maximum: 7
+    description:
+      Clock lane sampling phase in 40 ps steps. The hardware default is 3.
+
 required:
   - compatible
   - reg

-- 
2.34.1

[PATCH 3/3] phy: rockchip: phy-rockchip-inno-csidphy: add clock lane phase tuning

[Gerald Loacker]

At high data rates like 4K60 (2500 Mbps), such as when using an
LT6911GXD bridge chip on an RK3588 board, fixed default timing parameters
can cause signal integrity issues and clock-data recovery failures.
The driver currently lacks a mechanism to adjust the clock lane sampling
phase to compensate for board-specific trace variations.

Resolve this by parsing and applying the optional 'rockchip,clk-lane-phase'
device tree property. This enables board-specific tuning of the clock
lane sampling phase in ~40 ps steps (range 0-7) to optimize link
stability. If the property is absent, the driver falls back to the
hardware default.

Signed-off-by: Gerald Loacker <gerald.loacker@wolfvision.net>
---
 drivers/phy/rockchip/phy-rockchip-inno-csidphy.c | 25 ++++++++++++++++++++++++
 1 file changed, 25 insertions(+)

diff --git a/drivers/phy/rockchip/phy-rockchip-inno-csidphy.c b/drivers/phy/rockchip/phy-rockchip-inno-csidphy.c
index 5281f8dea0ad3..3a15840e86cad 100644
--- a/drivers/phy/rockchip/phy-rockchip-inno-csidphy.c
+++ b/drivers/phy/rockchip/phy-rockchip-inno-csidphy.c
@@ -69,6 +69,10 @@
 #define RK1808_CSIDPHY_CLK_CALIB_EN		0x168
 #define RK3568_CSIDPHY_CLK_CALIB_EN		0x168
 
+#define CSIDPHY_LANE_CLK_3_PHASE		0x38
+#define CSIDPHY_CLK_PHASE_MASK			GENMASK(6, 4)
+#define CSIDPHY_CLK_PHASE_DEFAULT		3
+
 #define RESETS_MAX				2
 
 /*
@@ -151,6 +155,7 @@ struct rockchip_inno_csidphy {
 	const struct dphy_drv_data *drv_data;
 	struct phy_configure_opts_mipi_dphy config;
 	u8 hsfreq;
+	int clk_phase;
 };
 
 static inline void write_grf_reg(struct rockchip_inno_csidphy *priv,
@@ -304,6 +309,13 @@ static int rockchip_inno_csidphy_power_on(struct phy *phy)
 		rockchip_inno_csidphy_ths_settle(priv, priv->hsfreq,
 						 CSIDPHY_LANE_THS_SETTLE(i));
 
+	if (priv->clk_phase >= 0) {
+		val = readl(priv->phy_base + CSIDPHY_LANE_CLK_3_PHASE);
+		val &= ~CSIDPHY_CLK_PHASE_MASK;
+		val |= FIELD_PREP(CSIDPHY_CLK_PHASE_MASK, priv->clk_phase);
+		writel(val, priv->phy_base + CSIDPHY_LANE_CLK_3_PHASE);
+	}
+
 	write_grf_reg(priv, GRF_DPHY_CSIPHY_CLKLANE_EN, 0x1);
 	write_grf_reg(priv, GRF_DPHY_CSIPHY_DATALANE_EN,
 		      GENMASK(priv->config.lanes - 1, 0));
@@ -449,6 +461,7 @@ static int rockchip_inno_csidphy_probe(struct platform_device *pdev)
 	struct device *dev = &pdev->dev;
 	struct phy_provider *phy_provider;
 	struct phy *phy;
+	u32 phase;
 	int ret;
 
 	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
@@ -464,6 +477,18 @@ static int rockchip_inno_csidphy_probe(struct platform_device *pdev)
 		return -ENODEV;
 	}
 
+	priv->clk_phase = -1;
+	if (device_property_read_u32(dev, "rockchip,clk-lane-phase",
+				     &phase) == 0) {
+		if (phase >= BIT(3)) {
+			dev_err(dev,
+				"rockchip,clk-lane-phase %u out of range [0,7]\n",
+				phase);
+			return -EINVAL;
+		}
+		priv->clk_phase = phase;
+	}
+
 	priv->grf = syscon_regmap_lookup_by_phandle(dev->of_node,
 						    "rockchip,grf");
 	if (IS_ERR(priv->grf)) {

-- 
2.34.1

Re: [PATCH 1/3] phy: rockchip: phy-rockchip-inno-csidphy: fix rk1808 hsfreq table

[sashiko-bot]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:

Pre-existing issues:
- [High] Valid low-frequency ranges mapping to configuration bit 0x00 are incorrectly rejected as errors.
--

commit 73e8683965255c344bec41b44d480c1cece33b57
Author: Gerald Loacker <gerald.loacker@wolfvision.net>

phy: rockchip: phy-rockchip-inno-csidphy: fix rk1808 hsfreq table

This commit extends the final entry in the rk1808 hsfreq table to exactly
2500 Mbps. This allows the RK3588, which reuses this array, to fully
support rates up to 2500 Mbps.

> diff --git a/drivers/phy/rockchip/phy-rockchip-inno-csidphy.c b/drivers/phy/rockchip/phy-rockchip-inno-csidphy.c
> index c79fb53d8ee5c..5281f8dea0ad3 100644
> --- a/drivers/phy/rockchip/phy-rockchip-inno-csidphy.c
> +++ b/drivers/phy/rockchip/phy-rockchip-inno-csidphy.c
> @@ -170,7 +170,7 @@ static const struct hsfreq_range rk1808_mipidphy_hsfreq_ranges[] = {
>  	{ 299, 0x06}, { 399, 0x08}, { 499, 0x0b}, { 599, 0x0e},
>  	{ 699, 0x10}, { 799, 0x12}, { 999, 0x16}, {1199, 0x1e},
>  	{1399, 0x23}, {1599, 0x2d}, {1799, 0x32}, {1999, 0x37},
> -	{2199, 0x3c}, {2399, 0x41}, {2499, 0x46}
> +	{2199, 0x3c}, {2399, 0x41}, {2500, 0x46}
>  };
>  
>  static const struct hsfreq_range rk3326_mipidphy_hsfreq_ranges[] = {

[Severity: High]
This is a pre-existing issue, but while looking at these frequency range
tables it appears that valid low-frequency configurations are incorrectly
rejected as errors.

In rockchip_inno_csidphy_configure(), the code iterates through the
hsfreq_ranges to find the cfg_bit:

drivers/phy/rockchip/phy-rockchip-inno-csidphy.c:rockchip_inno_csidphy_configure() {
    ...
    if (!hsfreq)
        return -EINVAL;
    ...
}

The rk3326_mipidphy_hsfreq_ranges table defines an entry for frequencies up
to 109 Mbps with a valid cfg_bit of 0x00:

    { 109, 0x00}, { 149, 0x01}, { 199, 0x02}, { 249, 0x03},

If the data rate falls into this lowest range, hsfreq is correctly set
to 0x00, but the subsequent if (!hsfreq) check evaluates to true and
incorrectly returns -EINVAL instead of applying the configuration.

A similar issue appears in rk_dphy_configure() inside 
drivers/phy/rockchip/phy-rockchip-dphy-rx0.c with tables like
rk3399_mipidphy_hsfreq_ranges which has { 89, 0x00 }.

Could this validation be modified to verify if a valid match was found 
during iteration rather than checking if the resulting configuration bit 
is non-zero?

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260617-feature-mipi-csi-dphy-4k60-v1-0-4611ff00b0ff@wolfvision.net?part=1

Re: [PATCH 3/3] phy: rockchip: phy-rockchip-inno-csidphy: add clock lane phase tuning

[sashiko-bot]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [Low] The macro `CSIDPHY_CLK_PHASE_DEFAULT` is defined but never used.
--

commit bfbb498bdd0c6aad9c80d6fe31b34f8a03261c76
Author: Gerald Loacker <gerald.loacker@wolfvision.net>

phy: rockchip: phy-rockchip-inno-csidphy: add clock lane phase tuning

This commit adds support for parsing and applying the optional
'rockchip,clk-lane-phase' device tree property. It allows for board-specific
tuning of the clock lane sampling phase. If the property is absent, the driver
relies on the hardware default without actively writing to the register.

> diff --git a/drivers/phy/rockchip/phy-rockchip-inno-csidphy.c b/drivers/phy/rockchip/phy-rockchip-inno-csidphy.c
> index 5281f8dea0ad3..3a15840e86cad 100644
> --- a/drivers/phy/rockchip/phy-rockchip-inno-csidphy.c
> +++ b/drivers/phy/rockchip/phy-rockchip-inno-csidphy.c
> @@ -69,6 +69,10 @@
>  #define RK1808_CSIDPHY_CLK_CALIB_EN		0x168
>  #define RK3568_CSIDPHY_CLK_CALIB_EN		0x168
>  
> +#define CSIDPHY_LANE_CLK_3_PHASE		0x38
> +#define CSIDPHY_CLK_PHASE_MASK			GENMASK(6, 4)
> +#define CSIDPHY_CLK_PHASE_DEFAULT		3

[Severity: Low]
This isn't a bug, but it looks like CSIDPHY_CLK_PHASE_DEFAULT is defined
here but never actually used in the driver code.

Since the fallback logic correctly relies on leaving the hardware at its
default state when the device tree property is missing (by initializing
clk_phase to -1), could this unused macro be removed to avoid keeping
dead code around?

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260617-feature-mipi-csi-dphy-4k60-v1-0-4611ff00b0ff@wolfvision.net?part=3

Re: [PATCH 2/3] dt-bindings: phy: rockchip-inno-csi-dphy: add rockchip,clk-lane-phase property

[Conor Dooley]

[-- Attachment #1: Type: text/plain, Size: 1474 bytes --]

On Wed, Jun 17, 2026 at 02:23:14PM +0200, Gerald Loacker wrote:
> Add support for the optional rockchip,clk-lane-phase device tree property
> to allow board-specific tuning of the clock lane sampling phase for
> improved signal integrity across supported data rates.
> 
> Signed-off-by: Gerald Loacker <gerald.loacker@wolfvision.net>
> ---
>  Documentation/devicetree/bindings/phy/rockchip-inno-csi-dphy.yaml | 7 +++++++
>  1 file changed, 7 insertions(+)
> 
> diff --git a/Documentation/devicetree/bindings/phy/rockchip-inno-csi-dphy.yaml b/Documentation/devicetree/bindings/phy/rockchip-inno-csi-dphy.yaml
> index 03950b3cad08c..0d824d1511bc0 100644
> --- a/Documentation/devicetree/bindings/phy/rockchip-inno-csi-dphy.yaml
> +++ b/Documentation/devicetree/bindings/phy/rockchip-inno-csi-dphy.yaml
> @@ -56,6 +56,13 @@ properties:
>      description:
>        Some additional phy settings are access through GRF regs.
>  
> +  rockchip,clk-lane-phase:
> +    $ref: /schemas/types.yaml#/definitions/uint32
> +    minimum: 0
> +    maximum: 7
> +    description:
> +      Clock lane sampling phase in 40 ps steps. The hardware default is 3.

Can this instead become rockchip,clk-lane-phase-ps and be listed in the
actual unit?
With the -ps suffix, you can then drop the $ref.
The default should be listed as "default: 3" (or default: 120)

pw-bot: changes-requested

> +
>  required:
>    - compatible
>    - reg
> 
> -- 
> 2.34.1
> 

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Re: [PATCH 2/3] dt-bindings: phy: rockchip-inno-csi-dphy: add rockchip,clk-lane-phase property

[Gerald Loacker]

Hi Conor,

Am 17.06.2026 um 17:51 schrieb Conor Dooley:
> On Wed, Jun 17, 2026 at 02:23:14PM +0200, Gerald Loacker wrote:
>> Add support for the optional rockchip,clk-lane-phase device tree property
>> to allow board-specific tuning of the clock lane sampling phase for
>> improved signal integrity across supported data rates.
>>
>> Signed-off-by: Gerald Loacker <gerald.loacker@wolfvision.net>
>> ---
>>  Documentation/devicetree/bindings/phy/rockchip-inno-csi-dphy.yaml | 7 +++++++
>>  1 file changed, 7 insertions(+)
>>
>> diff --git a/Documentation/devicetree/bindings/phy/rockchip-inno-csi-dphy.yaml b/Documentation/devicetree/bindings/phy/rockchip-inno-csi-dphy.yaml
>> index 03950b3cad08c..0d824d1511bc0 100644
>> --- a/Documentation/devicetree/bindings/phy/rockchip-inno-csi-dphy.yaml
>> +++ b/Documentation/devicetree/bindings/phy/rockchip-inno-csi-dphy.yaml
>> @@ -56,6 +56,13 @@ properties:
>>      description:
>>        Some additional phy settings are access through GRF regs.
>>  
>> +  rockchip,clk-lane-phase:
>> +    $ref: /schemas/types.yaml#/definitions/uint32
>> +    minimum: 0
>> +    maximum: 7
>> +    description:
>> +      Clock lane sampling phase in 40 ps steps. The hardware default is 3.
> 
> Can this instead become rockchip,clk-lane-phase-ps and be listed in the
> actual unit?
> With the -ps suffix, you can then drop the $ref.
> The default should be listed as "default: 3" (or default: 120)
> 
> pw-bot: changes-requested
> 

Thanks for the suggestion.

The phase setting is a hardware tap index (0–7) selecting a delay line
position. The datasheet mentions “about 40 ps” per step, but this is not
a calibrated or guaranteed value and may vary with PVT.

Because of that, I’d prefer to keep the property as an index and
document the approximate delay in the description:

Clock lane sampling phase selection (hardware tap index 0–7). Each step
corresponds to an approximately 40 ps delay as described in the hardware
specification.

This matches the hardware model more closely. Happy to adjust if needed.

>> +
>>  required:
>>    - compatible
>>    - reg
>>
>> -- 
>> 2.34.1
>>