Re: [PATCH v3 1/2] dt-bindings: PCI: xilinx-cpm: Add reset-gpios for PCIe RP PERST#

[Rob Herring <robh@kernel.org>]

On Thu, Feb 27, 2025 at 09:54:53AM +0530, Sai Krishna Musham wrote:
> Introduce `reset-gpios` property to enable GPIO-based control of
> the PCIe RP PERST# signal, generating assert and deassert signals.
> 
> Traditionally, the reset was managed in hardware and enabled during
> initialization. With this patch set, the reset will be handled by the
> driver. Consequently, the `reset-gpios` property must be explicitly
> provided to ensure proper functionality.
> 
> Signed-off-by: Sai Krishna Musham <sai.krishna.musham@amd.com>
> ---
> This patch depends on the following patch series.
> https://lore.kernel.org/all/20250217072713.635643-2-thippeswamy.havalige@amd.com/
> 
> Changes for v3:
> - None
> 
> Changes for v2:
> - Add define from include/dt-bindings/gpio/gpio.h for PERST# polarity
> - Update commit message
> ---
>  .../devicetree/bindings/pci/xilinx-versal-cpm.yaml         | 7 +++++++
>  1 file changed, 7 insertions(+)
> 
> diff --git a/Documentation/devicetree/bindings/pci/xilinx-versal-cpm.yaml b/Documentation/devicetree/bindings/pci/xilinx-versal-cpm.yaml
> index b63a759ec2d7..6aaeb76f498b 100644
> --- a/Documentation/devicetree/bindings/pci/xilinx-versal-cpm.yaml
> +++ b/Documentation/devicetree/bindings/pci/xilinx-versal-cpm.yaml
> @@ -33,6 +33,9 @@ properties:
>        - const: cpm_csr
>      minItems: 2
>  
> +  reset-gpios:
> +    description: GPIO used as PERST# signal. Please refer to pci.txt.

Drop 'Please refer to pci.txt'. pci.txt or portions of it need to be 
removed as schemas have replaced them.

> +
>    interrupts:
>      maxItems: 1
>  
> @@ -63,6 +66,7 @@ properties:
>  required:
>    - reg
>    - reg-names
> +  - reset-gpios
>    - "#interrupt-cells"
>    - interrupts
>    - interrupt-map
> @@ -75,6 +79,7 @@ unevaluatedProperties: false
>  
>  examples:
>    - |
> +    #include <dt-bindings/gpio/gpio.h>
>  
>      versal {
>                 #address-cells = <2>;
> @@ -99,6 +104,7 @@ examples:
>                         reg = <0x0 0xfca10000 0x0 0x1000>,
>                               <0x6 0x00000000 0x0 0x10000000>;
>                         reg-names = "cpm_slcr", "cfg";
> +                       reset-gpios = <&gpio1 38 GPIO_ACTIVE_LOW>;
>                         pcie_intc_0: interrupt-controller {
>                                 #address-cells = <0>;
>                                 #interrupt-cells = <1>;
> @@ -127,6 +133,7 @@ examples:
>                               <0x06 0x00000000 0x00 0x1000000>,
>                               <0x00 0xfce20000 0x00 0x1000000>;
>                         reg-names = "cpm_slcr", "cfg", "cpm_csr";
> +                       reset-gpios = <&gpio1 38 GPIO_ACTIVE_LOW>;
>  
>                         pcie_intc_1: interrupt-controller {
>                                 #address-cells = <0>;
> -- 
> 2.44.1
>