Add a base schema initially compatible with x1e80100 to describe MIPI CSI2
PHY devices.

The hardware can support both C-PHY and D-PHY modes. The CSIPHY devices
have their own pinouts on the SoC as well as their own individual voltage
rails.

The need to model voltage rails on a per-PHY basis leads us to define
CSIPHY devices as individual nodes.

Two nice outcomes in terms of schema and DT arise from this change.

1. The ability to define on a per-PHY basis voltage rails.
2. The ability to require those voltage.

We have had a complete bodge upstream for this where a single set of
voltage rail for all CSIPHYs has been buried inside of CAMSS.

Much like the I2C bus which is dedicated to Camera sensors - the CCI bus in
CAMSS parlance, the CSIPHY devices should be individually modelled.

Signed-off-by: Bryan O'Donoghue <bryan.odonoghue@linaro.org>
---
 .../bindings/phy/qcom,x1e80100-csi2-phy.yaml       | 114 +++++++++++++++++++++
 1 file changed, 114 insertions(+)

diff --git a/Documentation/devicetree/bindings/phy/qcom,x1e80100-csi2-phy.yaml b/Documentation/devicetree/bindings/phy/qcom,x1e80100-csi2-phy.yaml
new file mode 100644
index 0000000000000..c937d26ccbda9
--- /dev/null
+++ b/Documentation/devicetree/bindings/phy/qcom,x1e80100-csi2-phy.yaml
@@ -0,0 +1,114 @@
+# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/phy/qcom,x1e80100-csi2-phy.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Qualcomm CSI2 PHY
+
+maintainers:
+  - Bryan O'Donoghue <bod@kernel.org>
+
+description:
+  Qualcomm MIPI CSI2 C-PHY/D-PHY combination PHY. Connects MIPI CSI2 sensors
+  to Qualcomm's Camera CSI Decoder. The PHY supports both C-PHY and D-PHY
+  modes.
+
+properties:
+  compatible:
+    const: qcom,x1e80100-csi2-phy
+
+  reg:
+    maxItems: 1
+
+  "#phy-cells":
+    const: 1
+
+  clocks:
+    maxItems: 4
+
+  clock-names:
+    items:
+      - const: csiphy
+      - const: csiphy_timer
+      - const: camnoc_axi
+      - const: cpas_ahb
+
+  interrupts:
+    maxItems: 1
+
+  operating-points-v2:
+    maxItems: 1
+
+  power-domains:
+    maxItems: 1
+
+  vdda-0p8-supply:
+    description: Phandle to a 0.8V regulator supply to a PHY.
+
+  vdda-1p2-supply:
+    description: Phandle to 1.2V regulator supply to a PHY.
+
+required:
+  - compatible
+  - reg
+  - "#phy-cells"
+  - clocks
+  - clock-names
+  - interrupts
+  - operating-points-v2
+  - power-domains
+  - vdda-0p8-supply
+  - vdda-1p2-supply
+
+additionalProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/interrupt-controller/arm-gic.h>
+    #include <dt-bindings/clock/qcom,x1e80100-camcc.h>
+    #include <dt-bindings/clock/qcom,x1e80100-gcc.h>
+    #include <dt-bindings/phy/phy.h>
+
+    csiphy@ace4000 {
+        compatible = "qcom,x1e80100-csi2-phy";
+        reg = <0x0ace4000 0x2000>;
+        #phy-cells = <1>;
+
+        clocks = <&camcc CAM_CC_CSIPHY0_CLK>,
+                 <&camcc CAM_CC_CSI0PHYTIMER_CLK>,
+                 <&camcc CAM_CC_CAMNOC_AXI_RT_CLK>,
+                 <&camcc CAM_CC_CPAS_AHB_CLK>;
+        clock-names = "csiphy",
+                      "csiphy_timer",
+                      "camnoc_axi",
+                      "cpas_ahb";
+
+        operating-points-v2 = <&csiphy_opp_table>;
+
+        interrupts = <GIC_SPI 477 IRQ_TYPE_EDGE_RISING>;
+
+        power-domains = <&camcc CAM_CC_TITAN_TOP_GDSC>;
+
+        vdda-0p8-supply = <&vreg_l2c_0p8>;
+        vdda-1p2-supply = <&vreg_l1c_1p2>;
+    };
+
+    csiphy_opp_table: opp-table-csiphy {
+        compatible = "operating-points-v2";
+
+        opp-300000000 {
+            opp-hz = /bits/ 64 <300000000>;
+            required-opps = <&rpmhpd_opp_low_svs_d1>;
+        };
+
+        opp-400000000 {
+            opp-hz = /bits/ 64 <400000000>;
+            required-opps = <&rpmhpd_opp_low_svs>;
+        };
+
+        opp-480000000 {
+            opp-hz = /bits/ 64 <480000000>;
+            required-opps = <&rpmhpd_opp_low_svs>;
+        };
+    };

-- 
2.52.0

Hi Bryan,

On Wed, 2026-02-25 at 14:59 +0000, Bryan O'Donoghue wrote:
> Add a base schema initially compatible with x1e80100 to describe MIPI CSI2
> PHY devices.
> 
> The hardware can support both C-PHY and D-PHY modes. The CSIPHY devices
> have their own pinouts on the SoC as well as their own individual voltage
> rails.
> 
> The need to model voltage rails on a per-PHY basis leads us to define
> CSIPHY devices as individual nodes.
> 
> Two nice outcomes in terms of schema and DT arise from this change.
> 
> 1. The ability to define on a per-PHY basis voltage rails.
> 2. The ability to require those voltage.
> 
> We have had a complete bodge upstream for this where a single set of
> voltage rail for all CSIPHYs has been buried inside of CAMSS.
> 
> Much like the I2C bus which is dedicated to Camera sensors - the CCI bus in
> CAMSS parlance, the CSIPHY devices should be individually modelled.
> 
> Signed-off-by: Bryan O'Donoghue <bryan.odonoghue@linaro.org>
> ---

Reviewed-by: Christopher Obbard <christopher.obbard@linaro.org>

>  .../bindings/phy/qcom,x1e80100-csi2-phy.yaml       | 114 +++++++++++++++++++++
>  1 file changed, 114 insertions(+)
> 
> diff --git a/Documentation/devicetree/bindings/phy/qcom,x1e80100-csi2-phy.yaml b/Documentation/devicetree/bindings/phy/qcom,x1e80100-csi2-phy.yaml
> new file mode 100644
> index 0000000000000..c937d26ccbda9
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/phy/qcom,x1e80100-csi2-phy.yaml
> @@ -0,0 +1,114 @@
> +# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/phy/qcom,x1e80100-csi2-phy.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Qualcomm CSI2 PHY
> +
> +maintainers:
> +  - Bryan O'Donoghue <bod@kernel.org>
> +
> +description:
> +  Qualcomm MIPI CSI2 C-PHY/D-PHY combination PHY. Connects MIPI CSI2 sensors
> +  to Qualcomm's Camera CSI Decoder. The PHY supports both C-PHY and D-PHY
> +  modes.
> +
> +properties:
> +  compatible:
> +    const: qcom,x1e80100-csi2-phy
> +
> +  reg:
> +    maxItems: 1
> +
> +  "#phy-cells":
> +    const: 1
> +
> +  clocks:
> +    maxItems: 4
> +
> +  clock-names:
> +    items:
> +      - const: csiphy
> +      - const: csiphy_timer
> +      - const: camnoc_axi
> +      - const: cpas_ahb
> +
> +  interrupts:
> +    maxItems: 1
> +
> +  operating-points-v2:
> +    maxItems: 1
> +
> +  power-domains:
> +    maxItems: 1
> +
> +  vdda-0p8-supply:
> +    description: Phandle to a 0.8V regulator supply to a PHY.
> +
> +  vdda-1p2-supply:
> +    description: Phandle to 1.2V regulator supply to a PHY.
> +
> +required:
> +  - compatible
> +  - reg
> +  - "#phy-cells"
> +  - clocks
> +  - clock-names
> +  - interrupts
> +  - operating-points-v2
> +  - power-domains
> +  - vdda-0p8-supply
> +  - vdda-1p2-supply
> +
> +additionalProperties: false
> +
> +examples:
> +  - |
> +    #include <dt-bindings/interrupt-controller/arm-gic.h>
> +    #include <dt-bindings/clock/qcom,x1e80100-camcc.h>
> +    #include <dt-bindings/clock/qcom,x1e80100-gcc.h>
> +    #include <dt-bindings/phy/phy.h>
> +
> +    csiphy@ace4000 {
> +        compatible = "qcom,x1e80100-csi2-phy";
> +        reg = <0x0ace4000 0x2000>;
> +        #phy-cells = <1>;
> +
> +        clocks = <&camcc CAM_CC_CSIPHY0_CLK>,
> +                 <&camcc CAM_CC_CSI0PHYTIMER_CLK>,
> +                 <&camcc CAM_CC_CAMNOC_AXI_RT_CLK>,
> +                 <&camcc CAM_CC_CPAS_AHB_CLK>;
> +        clock-names = "csiphy",
> +                      "csiphy_timer",
> +                      "camnoc_axi",
> +                      "cpas_ahb";
> +
> +        operating-points-v2 = <&csiphy_opp_table>;
> +
> +        interrupts = <GIC_SPI 477 IRQ_TYPE_EDGE_RISING>;
> +
> +        power-domains = <&camcc CAM_CC_TITAN_TOP_GDSC>;
> +
> +        vdda-0p8-supply = <&vreg_l2c_0p8>;
> +        vdda-1p2-supply = <&vreg_l1c_1p2>;
> +    };
> +
> +    csiphy_opp_table: opp-table-csiphy {
> +        compatible = "operating-points-v2";
> +
> +        opp-300000000 {
> +            opp-hz = /bits/ 64 <300000000>;
> +            required-opps = <&rpmhpd_opp_low_svs_d1>;
> +        };
> +
> +        opp-400000000 {
> +            opp-hz = /bits/ 64 <400000000>;
> +            required-opps = <&rpmhpd_opp_low_svs>;
> +        };
> +
> +        opp-480000000 {
> +            opp-hz = /bits/ 64 <480000000>;
> +            required-opps = <&rpmhpd_opp_low_svs>;
> +        };
> +    };

On Wed, Feb 25, 2026 at 02:59:12PM +0000, Bryan O'Donoghue wrote:
> Add a base schema initially compatible with x1e80100 to describe MIPI CSI2
> PHY devices.
> 
> The hardware can support both C-PHY and D-PHY modes. The CSIPHY devices
> have their own pinouts on the SoC as well as their own individual voltage
> rails.
> 
> The need to model voltage rails on a per-PHY basis leads us to define
> CSIPHY devices as individual nodes.
> 
> Two nice outcomes in terms of schema and DT arise from this change.
> 
> 1. The ability to define on a per-PHY basis voltage rails.
> 2. The ability to require those voltage.
> 
> We have had a complete bodge upstream for this where a single set of
> voltage rail for all CSIPHYs has been buried inside of CAMSS.
> 
> Much like the I2C bus which is dedicated to Camera sensors - the CCI bus in
> CAMSS parlance, the CSIPHY devices should be individually modelled.
> 
> Signed-off-by: Bryan O'Donoghue <bryan.odonoghue@linaro.org>

The entire point of separate CSI PHY was to change new devices. That's
why I was postponing TWO new bindings. There is little point in change
existing bindings, it's just a lot of work with little benefit.

And the beauty is that you did not even had to do the work yourself,
because the contributors of new device would need to come with CSI PHY
split.

Best regards,
Krzysztof

On 26/02/2026 07:37, Krzysztof Kozlowski wrote:
> On Wed, Feb 25, 2026 at 02:59:12PM +0000, Bryan O'Donoghue wrote:
>> Add a base schema initially compatible with x1e80100 to describe MIPI CSI2
>> PHY devices.
>>
>> The hardware can support both C-PHY and D-PHY modes. The CSIPHY devices
>> have their own pinouts on the SoC as well as their own individual voltage
>> rails.
>>
>> The need to model voltage rails on a per-PHY basis leads us to define
>> CSIPHY devices as individual nodes.
>>
>> Two nice outcomes in terms of schema and DT arise from this change.
>>
>> 1. The ability to define on a per-PHY basis voltage rails.
>> 2. The ability to require those voltage.
>>
>> We have had a complete bodge upstream for this where a single set of
>> voltage rail for all CSIPHYs has been buried inside of CAMSS.
>>
>> Much like the I2C bus which is dedicated to Camera sensors - the CCI bus in
>> CAMSS parlance, the CSIPHY devices should be individually modelled.
>>
>> Signed-off-by: Bryan O'Donoghue <bryan.odonoghue@linaro.org>
> 
> The entire point of separate CSI PHY was to change new devices. That's
> why I was postponing TWO new bindings. There is little point in change
> existing bindings, it's just a lot of work with little benefit.

Since the x1e dtsi isn't upstream yet though.

> And the beauty is that you did not even had to do the work yourself,
> because the contributors of new device would need to come with CSI PHY
> split.
I mean I'm happy to do that work myself, idle hands make the Devil's work.

?

---
bod