[PATCH v2 0/4] pci: qcom: drop unrelated clock and add link_down reset for sa8775p

[PATCH v2 0/4] pci: qcom: drop unrelated clock and add link_down reset for sa8775p

[Ziyue Zhang]

This series drop gcc_aux_clock in pcie phy, the pcie aux clock should 
be gcc_phy_aux_clock. And sa8775p platform support link_down reset in
hardware, so add it for both pcie0 and pcie1 to provide a better user
experience.

Have follwing changes:
  - Update pcie phy bindings for sa8775p.
  - Document link_down reset.
  - Remove aux clock from pcie phy.
  - Add link_down reset for pcie.

Signed-off-by: Ziyue Zhang <quic_ziyuzhan@quicinc.com>

Changes in v2:
- Change link_down reset from optional to mandatory(Konrad)
- Link to v1: https://lore.kernel.org/all/20250529035416.4159963-1-quic_ziyuzhan@quicinc.com/


Ziyue Zhang (4):
  dt-bindings: phy: qcom,sc8280xp-qmp-pcie-phy: Update pcie phy bindings
    for sa8775p
  dt-bindings: PCI: qcom,pcie-sa8775p: document link_down reset
  arm64: dts: qcom: sa8775p: remove aux clock from pcie phy
  arm64: dts: qcom: sa8775p: add link_down reset for pcie

 .../bindings/pci/qcom,pcie-sa8775p.yaml       | 13 ++++--
 .../phy/qcom,sc8280xp-qmp-pcie-phy.yaml       |  4 +-
 arch/arm64/boot/dts/qcom/sa8775p.dtsi         | 42 ++++++++++++-------
 3 files changed, 37 insertions(+), 22 deletions(-)


base-commit: 4f27f06ec12190c7c62c722e99ab6243dea81a94
-- 
2.34.1

[PATCH v2 1/4] dt-bindings: phy: qcom,sc8280xp-qmp-pcie-phy: Update pcie phy bindings for sa8775p

[Ziyue Zhang]

The gcc_aux_clk is required by the PCIe controller but not by the PCIe
PHY. In PCIe PHY, the source of aux_clk used in low-power mode should
be gcc_phy_aux_clk. Hence, remove gcc_aux_clk and replace it with
gcc_phy_aux_clk.

Signed-off-by: Ziyue Zhang <quic_ziyuzhan@quicinc.com>
---
 .../devicetree/bindings/phy/qcom,sc8280xp-qmp-pcie-phy.yaml   | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/Documentation/devicetree/bindings/phy/qcom,sc8280xp-qmp-pcie-phy.yaml b/Documentation/devicetree/bindings/phy/qcom,sc8280xp-qmp-pcie-phy.yaml
index 2c6c9296e4c0..17fd6547d3b4 100644
--- a/Documentation/devicetree/bindings/phy/qcom,sc8280xp-qmp-pcie-phy.yaml
+++ b/Documentation/devicetree/bindings/phy/qcom,sc8280xp-qmp-pcie-phy.yaml
@@ -176,6 +176,8 @@ allOf:
           contains:
             enum:
               - qcom,qcs615-qmp-gen3x1-pcie-phy
+              - qcom,sa8775p-qmp-gen4x2-pcie-phy
+              - qcom,sa8775p-qmp-gen4x4-pcie-phy
               - qcom,sc8280xp-qmp-gen3x1-pcie-phy
               - qcom,sc8280xp-qmp-gen3x2-pcie-phy
               - qcom,sc8280xp-qmp-gen3x4-pcie-phy
@@ -197,8 +199,6 @@ allOf:
           contains:
             enum:
               - qcom,qcs8300-qmp-gen4x2-pcie-phy
-              - qcom,sa8775p-qmp-gen4x2-pcie-phy
-              - qcom,sa8775p-qmp-gen4x4-pcie-phy
     then:
       properties:
         clocks:
-- 
2.34.1

[PATCH v2 2/4] dt-bindings: PCI: qcom,pcie-sa8775p: document link_down reset

[Ziyue Zhang]

Each PCIe controller on sa8775p includes 'link_down'reset on hardware,
document it.

Signed-off-by: Ziyue Zhang <quic_ziyuzhan@quicinc.com>
---
 .../devicetree/bindings/pci/qcom,pcie-sa8775p.yaml  | 13 +++++++++----
 1 file changed, 9 insertions(+), 4 deletions(-)

diff --git a/Documentation/devicetree/bindings/pci/qcom,pcie-sa8775p.yaml b/Documentation/devicetree/bindings/pci/qcom,pcie-sa8775p.yaml
index e3fa232da2ca..b7cae2e556e3 100644
--- a/Documentation/devicetree/bindings/pci/qcom,pcie-sa8775p.yaml
+++ b/Documentation/devicetree/bindings/pci/qcom,pcie-sa8775p.yaml
@@ -61,11 +61,14 @@ properties:
       - const: global
 
   resets:
-    maxItems: 1
+    items:
+      - description: PCIe controller reset
+      - description: link_down reset
 
   reset-names:
     items:
-      - const: pci
+      - const: pci # PCIe core reset
+      - const: link_down # PCIe link down reset
 
 required:
   - interconnects
@@ -161,8 +164,10 @@ examples:
 
             power-domains = <&gcc PCIE_0_GDSC>;
 
-            resets = <&gcc GCC_PCIE_0_BCR>;
-            reset-names = "pci";
+            resets = <&gcc GCC_PCIE_0_BCR>,
+                     <&gcc GCC_PCIE_0_LINK_DOWN_BCR>;
+            reset-names = "pci",
+                          "link_down";
 
             perst-gpios = <&tlmm 2 GPIO_ACTIVE_LOW>;
             wake-gpios = <&tlmm 0 GPIO_ACTIVE_HIGH>;
-- 
2.34.1

[PATCH v2 3/4] arm64: dts: qcom: sa8775p: remove aux clock from pcie phy

[Ziyue Zhang]

gcc_aux_clk is used in PCIe RC and it is not required in pcie phy, in
pcie phy it should be gcc_phy_aux_clk, so remove gcc_aux_clk and
replace it with gcc_phy_aux_clk.

Signed-off-by: Ziyue Zhang <quic_ziyuzhan@quicinc.com>
---
 arch/arm64/boot/dts/qcom/sa8775p.dtsi | 28 +++++++++++++++------------
 1 file changed, 16 insertions(+), 12 deletions(-)

diff --git a/arch/arm64/boot/dts/qcom/sa8775p.dtsi b/arch/arm64/boot/dts/qcom/sa8775p.dtsi
index 45f536633f64..d7248014368b 100644
--- a/arch/arm64/boot/dts/qcom/sa8775p.dtsi
+++ b/arch/arm64/boot/dts/qcom/sa8775p.dtsi
@@ -7224,16 +7224,18 @@ pcie0_phy: phy@1c04000 {
 		compatible = "qcom,sa8775p-qmp-gen4x2-pcie-phy";
 		reg = <0x0 0x1c04000 0x0 0x2000>;
 
-		clocks = <&gcc GCC_PCIE_0_AUX_CLK>,
+		clocks = <&gcc GCC_PCIE_0_PHY_AUX_CLK>,
 			 <&gcc GCC_PCIE_0_CFG_AHB_CLK>,
 			 <&gcc GCC_PCIE_CLKREF_EN>,
 			 <&gcc GCC_PCIE_0_PHY_RCHNG_CLK>,
 			 <&gcc GCC_PCIE_0_PIPE_CLK>,
-			 <&gcc GCC_PCIE_0_PIPEDIV2_CLK>,
-			 <&gcc GCC_PCIE_0_PHY_AUX_CLK>;
-
-		clock-names = "aux", "cfg_ahb", "ref", "rchng", "pipe",
-			      "pipediv2", "phy_aux";
+			 <&gcc GCC_PCIE_0_PIPEDIV2_CLK>;
+		clock-names = "aux",
+			      "cfg_ahb",
+			      "ref",
+			      "rchng",
+			      "pipe",
+			      "pipediv2";
 
 		assigned-clocks = <&gcc GCC_PCIE_0_PHY_RCHNG_CLK>;
 		assigned-clock-rates = <100000000>;
@@ -7382,16 +7384,18 @@ pcie1_phy: phy@1c14000 {
 		compatible = "qcom,sa8775p-qmp-gen4x4-pcie-phy";
 		reg = <0x0 0x1c14000 0x0 0x4000>;
 
-		clocks = <&gcc GCC_PCIE_1_AUX_CLK>,
+		clocks = <&gcc GCC_PCIE_1_PHY_AUX_CLK>,
 			 <&gcc GCC_PCIE_1_CFG_AHB_CLK>,
 			 <&gcc GCC_PCIE_CLKREF_EN>,
 			 <&gcc GCC_PCIE_1_PHY_RCHNG_CLK>,
 			 <&gcc GCC_PCIE_1_PIPE_CLK>,
-			 <&gcc GCC_PCIE_1_PIPEDIV2_CLK>,
-			 <&gcc GCC_PCIE_1_PHY_AUX_CLK>;
-
-		clock-names = "aux", "cfg_ahb", "ref", "rchng", "pipe",
-			      "pipediv2", "phy_aux";
+			 <&gcc GCC_PCIE_1_PIPEDIV2_CLK>;
+		clock-names = "aux",
+			      "cfg_ahb",
+			      "ref",
+			      "rchng",
+			      "pipe",
+			      "pipediv2";
 
 		assigned-clocks = <&gcc GCC_PCIE_1_PHY_RCHNG_CLK>;
 		assigned-clock-rates = <100000000>;
-- 
2.34.1

[PATCH v2 4/4] arm64: dts: qcom: sa8775p: add link_down reset for pcie

[Ziyue Zhang]

SA8775p supports 'link_down' reset on hardware, so add it for both pcie0
and pcie1, which can provide a better user experience.

Reviewed-by: Konrad Dybcio <konrad.dybcio@oss.qualcomm.com>
Signed-off-by: Ziyue Zhang <quic_ziyuzhan@quicinc.com>
---
 arch/arm64/boot/dts/qcom/sa8775p.dtsi | 14 ++++++++++----
 1 file changed, 10 insertions(+), 4 deletions(-)

diff --git a/arch/arm64/boot/dts/qcom/sa8775p.dtsi b/arch/arm64/boot/dts/qcom/sa8775p.dtsi
index d7248014368b..c8ce3d42c894 100644
--- a/arch/arm64/boot/dts/qcom/sa8775p.dtsi
+++ b/arch/arm64/boot/dts/qcom/sa8775p.dtsi
@@ -7152,8 +7152,11 @@ pcie0: pcie@1c00000 {
 		iommu-map = <0x0 &pcie_smmu 0x0000 0x1>,
 			    <0x100 &pcie_smmu 0x0001 0x1>;
 
-		resets = <&gcc GCC_PCIE_0_BCR>;
-		reset-names = "pci";
+		resets = <&gcc GCC_PCIE_0_BCR>,
+			 <&gcc GCC_PCIE_0_LINK_DOWN_BCR>;
+		reset-names = "pci",
+			      "link_down";
+
 		power-domains = <&gcc PCIE_0_GDSC>;
 
 		phys = <&pcie0_phy>;
@@ -7312,8 +7315,11 @@ pcie1: pcie@1c10000 {
 		iommu-map = <0x0 &pcie_smmu 0x0080 0x1>,
 			    <0x100 &pcie_smmu 0x0081 0x1>;
 
-		resets = <&gcc GCC_PCIE_1_BCR>;
-		reset-names = "pci";
+		resets = <&gcc GCC_PCIE_1_BCR>,
+			 <&gcc GCC_PCIE_1_LINK_DOWN_BCR>;
+		reset-names = "pci",
+			      "link_down";
+
 		power-domains = <&gcc PCIE_1_GDSC>;
 
 		phys = <&pcie1_phy>;
-- 
2.34.1

Re: [PATCH v2 1/4] dt-bindings: phy: qcom,sc8280xp-qmp-pcie-phy: Update pcie phy bindings for sa8775p

[Johan Hovold]

On Tue, Jun 17, 2025 at 10:16:14AM +0800, Ziyue Zhang wrote:
> The gcc_aux_clk is required by the PCIe controller but not by the PCIe
> PHY. In PCIe PHY, the source of aux_clk used in low-power mode should
> be gcc_phy_aux_clk. Hence, remove gcc_aux_clk and replace it with
> gcc_phy_aux_clk.

> +++ b/Documentation/devicetree/bindings/phy/qcom,sc8280xp-qmp-pcie-phy.yaml
> @@ -176,6 +176,8 @@ allOf:
>            contains:
>              enum:
>                - qcom,qcs615-qmp-gen3x1-pcie-phy
> +              - qcom,sa8775p-qmp-gen4x2-pcie-phy
> +              - qcom,sa8775p-qmp-gen4x4-pcie-phy
>                - qcom,sc8280xp-qmp-gen3x1-pcie-phy
>                - qcom,sc8280xp-qmp-gen3x2-pcie-phy
>                - qcom,sc8280xp-qmp-gen3x4-pcie-phy
> @@ -197,8 +199,6 @@ allOf:
>            contains:
>              enum:
>                - qcom,qcs8300-qmp-gen4x2-pcie-phy

What about qcs8300, isn't this equally wrong for that platform?

> -              - qcom,sa8775p-qmp-gen4x2-pcie-phy
> -              - qcom,sa8775p-qmp-gen4x4-pcie-phy
>      then:
>        properties:
>          clocks:

Johan

Re: [PATCH v2 2/4] dt-bindings: PCI: qcom,pcie-sa8775p: document link_down reset

[Johan Hovold]

On Tue, Jun 17, 2025 at 10:16:15AM +0800, Ziyue Zhang wrote:
> Each PCIe controller on sa8775p includes 'link_down'reset on hardware,
> document it.

Please say something in the commit message about what this reset is used
for as well.

> Signed-off-by: Ziyue Zhang <quic_ziyuzhan@quicinc.com>
> ---
>  .../devicetree/bindings/pci/qcom,pcie-sa8775p.yaml  | 13 +++++++++----
>  1 file changed, 9 insertions(+), 4 deletions(-)
> 
> diff --git a/Documentation/devicetree/bindings/pci/qcom,pcie-sa8775p.yaml b/Documentation/devicetree/bindings/pci/qcom,pcie-sa8775p.yaml
> index e3fa232da2ca..b7cae2e556e3 100644
> --- a/Documentation/devicetree/bindings/pci/qcom,pcie-sa8775p.yaml
> +++ b/Documentation/devicetree/bindings/pci/qcom,pcie-sa8775p.yaml
> @@ -61,11 +61,14 @@ properties:
>        - const: global
>  
>    resets:
> -    maxItems: 1
> +    items:
> +      - description: PCIe controller reset
> +      - description: link_down reset

That's not really a description, you're just repeating the "link_down"
name here. You can probably use the description you add in the comment
below.

>    reset-names:
>      items:
> -      - const: pci
> +      - const: pci # PCIe core reset
> +      - const: link_down # PCIe link down reset

Johan