[PATCH 1/2] PCI/pwrctrl: Add optional slot clock to pwrctrl driver for PCI slots

[PATCH 1/2] PCI/pwrctrl: Add optional slot clock to pwrctrl driver for PCI slots

[Marek Vasut]

Add the ability to enable optional slot clock into the pwrctrl driver.
This is used to enable slot clock in split-clock topologies, where the
PCIe host/controller supply and PCIe slot supply are not provided by
the same clock. The PCIe host/controller clock should be described in
the controller node as the controller clock, while the slot clock should
be described in controller bridge/slot subnode.

Example DT snippet:
&pcicontroller {
    clocks = <&clk_dif 0>;             /* PCIe controller clock */

    pci@0,0 {
        #address-cells = <3>;
        #size-cells = <2>;
        reg = <0x0 0x0 0x0 0x0 0x0>;
        compatible = "pciclass,0604";
        device_type = "pci";
        clocks = <&clk_dif 1>;         /* PCIe slot clock */
        vpcie3v3-supply = <&reg_3p3v>;
        ranges;
    };
};

Example clock topology:
 ____________                    ____________
|  PCIe host |                  | PCIe slot  |
|            |                  |            |
|    PCIe RX<|==================|>PCIe TX    |
|    PCIe TX<|==================|>PCIe RX    |
|            |                  |            |
|   PCIe CLK<|======..  ..======|>PCIe CLK   |
'------------'      ||  ||      '------------'
                    ||  ||
 ____________       ||  ||
|  9FGV0441  |      ||  ||
|            |      ||  ||
|   CLK DIF0<|======''  ||
|   CLK DIF1<|==========''
|   CLK DIF2<|
|   CLK DIF3<|
'------------'

Signed-off-by: Marek Vasut <marek.vasut+renesas@mailbox.org>
---
Cc: Bartosz Golaszewski <brgl@bgdev.pl>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Conor Dooley <conor+dt@kernel.org>
Cc: Geert Uytterhoeven <geert+renesas@glider.be>
Cc: Krzysztof Kozlowski <krzk+dt@kernel.org>
Cc: Magnus Damm <magnus.damm@gmail.com>
Cc: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Cc: Rob Herring <robh@kernel.org>
Cc: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Cc: devicetree@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: linux-pci@vger.kernel.org
Cc: linux-renesas-soc@vger.kernel.org
---
 drivers/pci/pwrctrl/slot.c | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/drivers/pci/pwrctrl/slot.c b/drivers/pci/pwrctrl/slot.c
index 18becc144913e..222c14056cfae 100644
--- a/drivers/pci/pwrctrl/slot.c
+++ b/drivers/pci/pwrctrl/slot.c
@@ -4,6 +4,7 @@
  * Author: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
  */
 
+#include <linux/clk.h>
 #include <linux/device.h>
 #include <linux/mod_devicetable.h>
 #include <linux/module.h>
@@ -30,6 +31,7 @@ static int pci_pwrctrl_slot_probe(struct platform_device *pdev)
 {
 	struct pci_pwrctrl_slot_data *slot;
 	struct device *dev = &pdev->dev;
+	struct clk *clk;
 	int ret;
 
 	slot = devm_kzalloc(dev, sizeof(*slot), GFP_KERNEL);
@@ -50,6 +52,13 @@ static int pci_pwrctrl_slot_probe(struct platform_device *pdev)
 		goto err_regulator_free;
 	}
 
+	clk = devm_clk_get_optional_enabled(dev, NULL);
+	if (IS_ERR(clk)) {
+		ret = PTR_ERR(clk);
+		dev_err_probe(dev, ret, "Failed to enable slot clock\n");
+		goto err_regulator_disable;
+	}
+
 	ret = devm_add_action_or_reset(dev, devm_pci_pwrctrl_slot_power_off,
 				       slot);
 	if (ret)
-- 
2.47.2

[PATCH 2/2] arm64: dts: renesas: r8a779g3: Describe split PCIe clock on V4H Sparrow Hawk

[Marek Vasut]

The V4H Sparrow Hawk board supplies PCIe controller input clock and PCIe
bus clock from separate outputs of Renesas 9FGV0441 clock generator chip.
Describe this split bus configuration in the board DT. The topology looks
as follows:

 ____________                    _____________
| R-Car PCIe |                  | PCIe device |
|            |                  |             |
|    PCIe RX<|==================|>PCIe TX     |
|    PCIe TX<|==================|>PCIe RX     |
|            |                  |             |
|   PCIe CLK<|======..  ..======|>PCIe CLK    |
'------------'      ||  ||      '-------------'
                    ||  ||
 ____________       ||  ||
|  9FGV0441  |      ||  ||
|            |      ||  ||
|   CLK DIF0<|======''  ||
|   CLK DIF1<|==========''
|   CLK DIF2<|
|   CLK DIF3<|
'------------'

Signed-off-by: Marek Vasut <marek.vasut+renesas@mailbox.org>
---
Cc: Bartosz Golaszewski <brgl@bgdev.pl>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Conor Dooley <conor+dt@kernel.org>
Cc: Geert Uytterhoeven <geert+renesas@glider.be>
Cc: Krzysztof Kozlowski <krzk+dt@kernel.org>
Cc: Magnus Damm <magnus.damm@gmail.com>
Cc: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Cc: Rob Herring <robh@kernel.org>
Cc: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Cc: devicetree@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: linux-pci@vger.kernel.org
Cc: linux-renesas-soc@vger.kernel.org
---
 .../dts/renesas/r8a779g3-sparrow-hawk.dts     | 45 ++++++++++++++++++-
 1 file changed, 43 insertions(+), 2 deletions(-)

diff --git a/arch/arm64/boot/dts/renesas/r8a779g3-sparrow-hawk.dts b/arch/arm64/boot/dts/renesas/r8a779g3-sparrow-hawk.dts
index b8698e07add56..7c050a56290fd 100644
--- a/arch/arm64/boot/dts/renesas/r8a779g3-sparrow-hawk.dts
+++ b/arch/arm64/boot/dts/renesas/r8a779g3-sparrow-hawk.dts
@@ -130,6 +130,13 @@ mini_dp_con_in: endpoint {
 		};
 	};
 
+	/* Page 26 / PCIe.0/1 CLK */
+	pcie_refclk: clk-x8 {
+		compatible = "fixed-clock";
+		#clock-cells = <0>;
+		clock-frequency = <25000000>;
+	};
+
 	reg_1p2v: regulator-1p2v {
 		compatible = "regulator-fixed";
 		regulator-name = "fixed-1.2V";
@@ -404,6 +411,14 @@ i2c0_mux2: i2c@2 {
 			reg = <2>;
 			#address-cells = <1>;
 			#size-cells = <0>;
+
+			/* Page 26 / PCIe.0/1 CLK */
+			pcie_clk: clk@68 {
+				compatible = "renesas,9fgv0441";
+				reg = <0x68>;
+				clocks = <&pcie_refclk>;
+				#clock-cells = <1>;
+			};
 		};
 
 		i2c0_mux3: i2c@3 {
@@ -487,24 +502,50 @@ msiof1_snd_endpoint: endpoint {
 
 /* Page 26 / 2230 Key M M.2 */
 &pcie0_clkref {
-	clock-frequency = <100000000>;
+	status = "disabled";
 };
 
 &pciec0 {
+	clocks = <&cpg CPG_MOD 624>, <&pcie_clk 0>;
 	reset-gpios = <&gpio2 2 GPIO_ACTIVE_LOW>;
 	status = "okay";
+
+	/* PCIe bridge, Root Port */
+	pci@0,0 {
+		#address-cells = <3>;
+		#size-cells = <2>;
+		reg = <0x0 0x0 0x0 0x0 0x0>;
+		compatible = "pciclass,0604";
+		device_type = "pci";
+		clocks = <&pcie_clk 1>;
+		vpcie3v3-supply = <&reg_3p3v>;
+		ranges;
+	};
 };
 
 /* Page 25 / PCIe to USB */
 &pcie1_clkref {
-	clock-frequency = <100000000>;
+	status = "disabled";
 };
 
 &pciec1 {
+	clocks = <&cpg CPG_MOD 625>, <&pcie_clk 2>;
 	/* uPD720201 is PCIe Gen2 x1 device */
 	num-lanes = <1>;
 	reset-gpios = <&gpio2 0 GPIO_ACTIVE_LOW>;
 	status = "okay";
+
+	/* PCIe bridge, Root Port */
+	pci@0,0 {
+		#address-cells = <3>;
+		#size-cells = <2>;
+		reg = <0x0 0x0 0x0 0x0 0x0>;
+		compatible = "pciclass,0604";
+		device_type = "pci";
+		clocks = <&pcie_clk 3>;
+		vpcie3v3-supply = <&reg_3p3v>;
+		ranges;
+	};
 };
 
 &pfc {
-- 
2.47.2

Re: [PATCH 2/2] arm64: dts: renesas: r8a779g3: Describe split PCIe clock on V4H Sparrow Hawk

[Manivannan Sadhasivam]

On Sun, May 25, 2025 at 06:04:04PM +0200, Marek Vasut wrote:
> The V4H Sparrow Hawk board supplies PCIe controller input clock and PCIe
> bus clock from separate outputs of Renesas 9FGV0441 clock generator chip.
> Describe this split bus configuration in the board DT. The topology looks
> as follows:
> 
>  ____________                    _____________
> | R-Car PCIe |                  | PCIe device |
> |            |                  |             |
> |    PCIe RX<|==================|>PCIe TX     |
> |    PCIe TX<|==================|>PCIe RX     |
> |            |                  |             |
> |   PCIe CLK<|======..  ..======|>PCIe CLK    |
> '------------'      ||  ||      '-------------'
>                     ||  ||
>  ____________       ||  ||
> |  9FGV0441  |      ||  ||
> |            |      ||  ||
> |   CLK DIF0<|======''  ||
> |   CLK DIF1<|==========''
> |   CLK DIF2<|
> |   CLK DIF3<|
> '------------'
> 
> Signed-off-by: Marek Vasut <marek.vasut+renesas@mailbox.org>
> ---
> Cc: Bartosz Golaszewski <brgl@bgdev.pl>
> Cc: Bjorn Helgaas <bhelgaas@google.com>
> Cc: Conor Dooley <conor+dt@kernel.org>
> Cc: Geert Uytterhoeven <geert+renesas@glider.be>
> Cc: Krzysztof Kozlowski <krzk+dt@kernel.org>
> Cc: Magnus Damm <magnus.damm@gmail.com>
> Cc: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
> Cc: Rob Herring <robh@kernel.org>
> Cc: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
> Cc: devicetree@vger.kernel.org
> Cc: linux-kernel@vger.kernel.org
> Cc: linux-pci@vger.kernel.org
> Cc: linux-renesas-soc@vger.kernel.org
> ---
>  .../dts/renesas/r8a779g3-sparrow-hawk.dts     | 45 ++++++++++++++++++-
>  1 file changed, 43 insertions(+), 2 deletions(-)
> 
> diff --git a/arch/arm64/boot/dts/renesas/r8a779g3-sparrow-hawk.dts b/arch/arm64/boot/dts/renesas/r8a779g3-sparrow-hawk.dts
> index b8698e07add56..7c050a56290fd 100644
> --- a/arch/arm64/boot/dts/renesas/r8a779g3-sparrow-hawk.dts
> +++ b/arch/arm64/boot/dts/renesas/r8a779g3-sparrow-hawk.dts
> @@ -130,6 +130,13 @@ mini_dp_con_in: endpoint {
>  		};
>  	};
>  
> +	/* Page 26 / PCIe.0/1 CLK */
> +	pcie_refclk: clk-x8 {
> +		compatible = "fixed-clock";
> +		#clock-cells = <0>;
> +		clock-frequency = <25000000>;
> +	};
> +
>  	reg_1p2v: regulator-1p2v {
>  		compatible = "regulator-fixed";
>  		regulator-name = "fixed-1.2V";
> @@ -404,6 +411,14 @@ i2c0_mux2: i2c@2 {
>  			reg = <2>;
>  			#address-cells = <1>;
>  			#size-cells = <0>;
> +
> +			/* Page 26 / PCIe.0/1 CLK */
> +			pcie_clk: clk@68 {
> +				compatible = "renesas,9fgv0441";
> +				reg = <0x68>;
> +				clocks = <&pcie_refclk>;
> +				#clock-cells = <1>;
> +			};
>  		};
>  
>  		i2c0_mux3: i2c@3 {
> @@ -487,24 +502,50 @@ msiof1_snd_endpoint: endpoint {
>  
>  /* Page 26 / 2230 Key M M.2 */
>  &pcie0_clkref {
> -	clock-frequency = <100000000>;
> +	status = "disabled";
>  };
>  
>  &pciec0 {
> +	clocks = <&cpg CPG_MOD 624>, <&pcie_clk 0>;
>  	reset-gpios = <&gpio2 2 GPIO_ACTIVE_LOW>;
>  	status = "okay";
> +
> +	/* PCIe bridge, Root Port */
> +	pci@0,0 {

PCIe bridge mostly is integrated into the SoC itself. So it should be defined
in the SoC dtsi. Only the vpcie3v3-supply is board specific, so it should live
in board dts.

- Mani

> +		#address-cells = <3>;
> +		#size-cells = <2>;
> +		reg = <0x0 0x0 0x0 0x0 0x0>;
> +		compatible = "pciclass,0604";
> +		device_type = "pci";
> +		clocks = <&pcie_clk 1>;
> +		vpcie3v3-supply = <&reg_3p3v>;
> +		ranges;
> +	};
>  };
>  
>  /* Page 25 / PCIe to USB */
>  &pcie1_clkref {
> -	clock-frequency = <100000000>;
> +	status = "disabled";
>  };
>  
>  &pciec1 {
> +	clocks = <&cpg CPG_MOD 625>, <&pcie_clk 2>;
>  	/* uPD720201 is PCIe Gen2 x1 device */
>  	num-lanes = <1>;
>  	reset-gpios = <&gpio2 0 GPIO_ACTIVE_LOW>;
>  	status = "okay";
> +
> +	/* PCIe bridge, Root Port */
> +	pci@0,0 {
> +		#address-cells = <3>;
> +		#size-cells = <2>;
> +		reg = <0x0 0x0 0x0 0x0 0x0>;
> +		compatible = "pciclass,0604";
> +		device_type = "pci";
> +		clocks = <&pcie_clk 3>;
> +		vpcie3v3-supply = <&reg_3p3v>;
> +		ranges;
> +	};
>  };
>  
>  &pfc {
> -- 
> 2.47.2
> 

-- 
மணிவண்ணன் சதாசிவம்

Re: [PATCH 2/2] arm64: dts: renesas: r8a779g3: Describe split PCIe clock on V4H Sparrow Hawk

[Geert Uytterhoeven]

Hi Mani,

On Wed, 28 May 2025 at 05:50, Manivannan Sadhasivam
<manivannan.sadhasivam@linaro.org> wrote:
> On Sun, May 25, 2025 at 06:04:04PM +0200, Marek Vasut wrote:
> > The V4H Sparrow Hawk board supplies PCIe controller input clock and PCIe
> > bus clock from separate outputs of Renesas 9FGV0441 clock generator chip.
> > Describe this split bus configuration in the board DT. The topology looks
> > as follows:
> >
> >  ____________                    _____________
> > | R-Car PCIe |                  | PCIe device |
> > |            |                  |             |
> > |    PCIe RX<|==================|>PCIe TX     |
> > |    PCIe TX<|==================|>PCIe RX     |
> > |            |                  |             |
> > |   PCIe CLK<|======..  ..======|>PCIe CLK    |
> > '------------'      ||  ||      '-------------'
> >                     ||  ||
> >  ____________       ||  ||
> > |  9FGV0441  |      ||  ||
> > |            |      ||  ||
> > |   CLK DIF0<|======''  ||
> > |   CLK DIF1<|==========''
> > |   CLK DIF2<|
> > |   CLK DIF3<|
> > '------------'
> >
> > Signed-off-by: Marek Vasut <marek.vasut+renesas@mailbox.org>
> > ---
> > Cc: Bartosz Golaszewski <brgl@bgdev.pl>
> > Cc: Bjorn Helgaas <bhelgaas@google.com>
> > Cc: Conor Dooley <conor+dt@kernel.org>
> > Cc: Geert Uytterhoeven <geert+renesas@glider.be>
> > Cc: Krzysztof Kozlowski <krzk+dt@kernel.org>
> > Cc: Magnus Damm <magnus.damm@gmail.com>
> > Cc: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
> > Cc: Rob Herring <robh@kernel.org>
> > Cc: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
> > Cc: devicetree@vger.kernel.org
> > Cc: linux-kernel@vger.kernel.org
> > Cc: linux-pci@vger.kernel.org
> > Cc: linux-renesas-soc@vger.kernel.org
> > ---
> >  .../dts/renesas/r8a779g3-sparrow-hawk.dts     | 45 ++++++++++++++++++-
> >  1 file changed, 43 insertions(+), 2 deletions(-)
> >
> > diff --git a/arch/arm64/boot/dts/renesas/r8a779g3-sparrow-hawk.dts b/arch/arm64/boot/dts/renesas/r8a779g3-sparrow-hawk.dts
> > index b8698e07add56..7c050a56290fd 100644
> > --- a/arch/arm64/boot/dts/renesas/r8a779g3-sparrow-hawk.dts
> > +++ b/arch/arm64/boot/dts/renesas/r8a779g3-sparrow-hawk.dts
> > @@ -130,6 +130,13 @@ mini_dp_con_in: endpoint {
> >               };
> >       };
> >
> > +     /* Page 26 / PCIe.0/1 CLK */
> > +     pcie_refclk: clk-x8 {
> > +             compatible = "fixed-clock";
> > +             #clock-cells = <0>;
> > +             clock-frequency = <25000000>;
> > +     };
> > +
> >       reg_1p2v: regulator-1p2v {
> >               compatible = "regulator-fixed";
> >               regulator-name = "fixed-1.2V";
> > @@ -404,6 +411,14 @@ i2c0_mux2: i2c@2 {
> >                       reg = <2>;
> >                       #address-cells = <1>;
> >                       #size-cells = <0>;
> > +
> > +                     /* Page 26 / PCIe.0/1 CLK */
> > +                     pcie_clk: clk@68 {
> > +                             compatible = "renesas,9fgv0441";
> > +                             reg = <0x68>;
> > +                             clocks = <&pcie_refclk>;
> > +                             #clock-cells = <1>;
> > +                     };
> >               };
> >
> >               i2c0_mux3: i2c@3 {
> > @@ -487,24 +502,50 @@ msiof1_snd_endpoint: endpoint {
> >
> >  /* Page 26 / 2230 Key M M.2 */
> >  &pcie0_clkref {
> > -     clock-frequency = <100000000>;
> > +     status = "disabled";
> >  };
> >
> >  &pciec0 {
> > +     clocks = <&cpg CPG_MOD 624>, <&pcie_clk 0>;
> >       reset-gpios = <&gpio2 2 GPIO_ACTIVE_LOW>;
> >       status = "okay";
> > +
> > +     /* PCIe bridge, Root Port */
> > +     pci@0,0 {
>
> PCIe bridge mostly is integrated into the SoC itself. So it should be defined
> in the SoC dtsi. Only the vpcie3v3-supply is board specific, so it should live
> in board dts.

... and the clocks property, of course, which is the main subject of this patch.

> > +             #address-cells = <3>;
> > +             #size-cells = <2>;
> > +             reg = <0x0 0x0 0x0 0x0 0x0>;
> > +             compatible = "pciclass,0604";
> > +             device_type = "pci";
> > +             clocks = <&pcie_clk 1>;
> > +             vpcie3v3-supply = <&reg_3p3v>;
> > +             ranges;
> > +     };
> >  };

Gr{oetje,eeting}s,

                        Geert

-- 
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds

Re: [PATCH 1/2] PCI/pwrctrl: Add optional slot clock to pwrctrl driver for PCI slots

[Manivannan Sadhasivam]

On Sun, May 25, 2025 at 06:04:03PM +0200, Marek Vasut wrote:
> Add the ability to enable optional slot clock into the pwrctrl driver.
> This is used to enable slot clock in split-clock topologies, where the
> PCIe host/controller supply and PCIe slot supply are not provided by
> the same clock. The PCIe host/controller clock should be described in
> the controller node as the controller clock, while the slot clock should
> be described in controller bridge/slot subnode.
> 
> Example DT snippet:
> &pcicontroller {
>     clocks = <&clk_dif 0>;             /* PCIe controller clock */
> 
>     pci@0,0 {
>         #address-cells = <3>;
>         #size-cells = <2>;
>         reg = <0x0 0x0 0x0 0x0 0x0>;
>         compatible = "pciclass,0604";
>         device_type = "pci";
>         clocks = <&clk_dif 1>;         /* PCIe slot clock */
>         vpcie3v3-supply = <&reg_3p3v>;
>         ranges;
>     };
> };
> 
> Example clock topology:
>  ____________                    ____________
> |  PCIe host |                  | PCIe slot  |
> |            |                  |            |
> |    PCIe RX<|==================|>PCIe TX    |
> |    PCIe TX<|==================|>PCIe RX    |
> |            |                  |            |
> |   PCIe CLK<|======..  ..======|>PCIe CLK   |
> '------------'      ||  ||      '------------'
>                     ||  ||
>  ____________       ||  ||
> |  9FGV0441  |      ||  ||
> |            |      ||  ||
> |   CLK DIF0<|======''  ||
> |   CLK DIF1<|==========''
> |   CLK DIF2<|
> |   CLK DIF3<|
> '------------'
> 
> Signed-off-by: Marek Vasut <marek.vasut+renesas@mailbox.org>

Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>

- Mani

> ---
> Cc: Bartosz Golaszewski <brgl@bgdev.pl>
> Cc: Bjorn Helgaas <bhelgaas@google.com>
> Cc: Conor Dooley <conor+dt@kernel.org>
> Cc: Geert Uytterhoeven <geert+renesas@glider.be>
> Cc: Krzysztof Kozlowski <krzk+dt@kernel.org>
> Cc: Magnus Damm <magnus.damm@gmail.com>
> Cc: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
> Cc: Rob Herring <robh@kernel.org>
> Cc: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
> Cc: devicetree@vger.kernel.org
> Cc: linux-kernel@vger.kernel.org
> Cc: linux-pci@vger.kernel.org
> Cc: linux-renesas-soc@vger.kernel.org
> ---
>  drivers/pci/pwrctrl/slot.c | 9 +++++++++
>  1 file changed, 9 insertions(+)
> 
> diff --git a/drivers/pci/pwrctrl/slot.c b/drivers/pci/pwrctrl/slot.c
> index 18becc144913e..222c14056cfae 100644
> --- a/drivers/pci/pwrctrl/slot.c
> +++ b/drivers/pci/pwrctrl/slot.c
> @@ -4,6 +4,7 @@
>   * Author: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
>   */
>  
> +#include <linux/clk.h>
>  #include <linux/device.h>
>  #include <linux/mod_devicetable.h>
>  #include <linux/module.h>
> @@ -30,6 +31,7 @@ static int pci_pwrctrl_slot_probe(struct platform_device *pdev)
>  {
>  	struct pci_pwrctrl_slot_data *slot;
>  	struct device *dev = &pdev->dev;
> +	struct clk *clk;
>  	int ret;
>  
>  	slot = devm_kzalloc(dev, sizeof(*slot), GFP_KERNEL);
> @@ -50,6 +52,13 @@ static int pci_pwrctrl_slot_probe(struct platform_device *pdev)
>  		goto err_regulator_free;
>  	}
>  
> +	clk = devm_clk_get_optional_enabled(dev, NULL);
> +	if (IS_ERR(clk)) {
> +		ret = PTR_ERR(clk);
> +		dev_err_probe(dev, ret, "Failed to enable slot clock\n");
> +		goto err_regulator_disable;
> +	}
> +
>  	ret = devm_add_action_or_reset(dev, devm_pci_pwrctrl_slot_power_off,
>  				       slot);
>  	if (ret)
> -- 
> 2.47.2
> 

-- 
மணிவண்ணன் சதாசிவம்

Re: [PATCH 1/2] PCI/pwrctrl: Add optional slot clock to pwrctrl driver for PCI slots

[Anand Moon]

Hi Marek,

On Sun, 25 May 2025 at 21:35, Marek Vasut
<marek.vasut+renesas@mailbox.org> wrote:
>
> Add the ability to enable optional slot clock into the pwrctrl driver.
> This is used to enable slot clock in split-clock topologies, where the
> PCIe host/controller supply and PCIe slot supply are not provided by
> the same clock. The PCIe host/controller clock should be described in
> the controller node as the controller clock, while the slot clock should
> be described in controller bridge/slot subnode.
>
> Example DT snippet:
> &pcicontroller {
>     clocks = <&clk_dif 0>;             /* PCIe controller clock */
>
>     pci@0,0 {
>         #address-cells = <3>;
>         #size-cells = <2>;
>         reg = <0x0 0x0 0x0 0x0 0x0>;
>         compatible = "pciclass,0604";
>         device_type = "pci";
>         clocks = <&clk_dif 1>;         /* PCIe slot clock */
>         vpcie3v3-supply = <&reg_3p3v>;
>         ranges;
>     };
> };
>
> Example clock topology:
>  ____________                    ____________
> |  PCIe host |                  | PCIe slot  |
> |            |                  |            |
> |    PCIe RX<|==================|>PCIe TX    |
> |    PCIe TX<|==================|>PCIe RX    |
> |            |                  |            |
> |   PCIe CLK<|======..  ..======|>PCIe CLK   |
> '------------'      ||  ||      '------------'
>                     ||  ||
>  ____________       ||  ||
> |  9FGV0441  |      ||  ||
> |            |      ||  ||
> |   CLK DIF0<|======''  ||
> |   CLK DIF1<|==========''
> |   CLK DIF2<|
> |   CLK DIF3<|
> '------------'
>
> Signed-off-by: Marek Vasut <marek.vasut+renesas@mailbox.org>
> ---
> Cc: Bartosz Golaszewski <brgl@bgdev.pl>
> Cc: Bjorn Helgaas <bhelgaas@google.com>
> Cc: Conor Dooley <conor+dt@kernel.org>
> Cc: Geert Uytterhoeven <geert+renesas@glider.be>
> Cc: Krzysztof Kozlowski <krzk+dt@kernel.org>
> Cc: Magnus Damm <magnus.damm@gmail.com>
> Cc: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
> Cc: Rob Herring <robh@kernel.org>
> Cc: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
> Cc: devicetree@vger.kernel.org
> Cc: linux-kernel@vger.kernel.org
> Cc: linux-pci@vger.kernel.org
> Cc: linux-renesas-soc@vger.kernel.org
> ---
>  drivers/pci/pwrctrl/slot.c | 9 +++++++++
>  1 file changed, 9 insertions(+)
>
> diff --git a/drivers/pci/pwrctrl/slot.c b/drivers/pci/pwrctrl/slot.c
> index 18becc144913e..222c14056cfae 100644
> --- a/drivers/pci/pwrctrl/slot.c
> +++ b/drivers/pci/pwrctrl/slot.c
> @@ -4,6 +4,7 @@
>   * Author: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
>   */
>
> +#include <linux/clk.h>
>  #include <linux/device.h>
>  #include <linux/mod_devicetable.h>
>  #include <linux/module.h>
> @@ -30,6 +31,7 @@ static int pci_pwrctrl_slot_probe(struct platform_device *pdev)
>  {
>         struct pci_pwrctrl_slot_data *slot;
>         struct device *dev = &pdev->dev;
> +       struct clk *clk;
>         int ret;
>
>         slot = devm_kzalloc(dev, sizeof(*slot), GFP_KERNEL);
> @@ -50,6 +52,13 @@ static int pci_pwrctrl_slot_probe(struct platform_device *pdev)
>                 goto err_regulator_free;
>         }
>
> +       clk = devm_clk_get_optional_enabled(dev, NULL);
> +       if (IS_ERR(clk)) {
> +               ret = PTR_ERR(clk);
> +               dev_err_probe(dev, ret, "Failed to enable slot clock\n");
you can user the return from ret = dev_err_probe()
> +               goto err_regulator_disable;
> +       }
> +
>         ret = devm_add_action_or_reset(dev, devm_pci_pwrctrl_slot_power_off,
>                                        slot);
>         if (ret)

with that change.
Reviewed-by: Anand Moon <linux.amoon@gmail.com>

Thanks
-Anand
> --
> 2.47.2
>
>