PCI: imx6: add regulator support

Message ID 20170608080742.3910-1-quentin.schulz@free-electrons.com
State New
Headers show

Commit Message

Quentin Schulz June 8, 2017, 8:07 a.m.
Some boards might require to control a regulator to power the PCIe port.

This adds support for an optional regulator defined in Device Tree
linked in the PCIe controller under `vpcie-supply`. If present, the
regulator will be disabled and then enabled as part of the PCIe host
initialization process and will be disabled when shutting down.

Signed-off-by: Quentin Schulz <quentin.schulz@free-electrons.com>

---
 .../devicetree/bindings/pci/fsl,imx6q-pcie.txt     |  4 +++
 drivers/pci/dwc/pci-imx6.c                         | 34 +++++++++++++++++++++-
 2 files changed, 37 insertions(+), 1 deletion(-)

-- 
2.11.0

--
To unsubscribe from this list: send the line "unsubscribe devicetree" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Comments

Bjorn Helgaas June 15, 2017, 9:05 p.m. | #1
On Thu, Jun 08, 2017 at 10:07:42AM +0200, Quentin Schulz wrote:
> Some boards might require to control a regulator to power the PCIe port.

> 

> This adds support for an optional regulator defined in Device Tree

> linked in the PCIe controller under `vpcie-supply`. If present, the

> regulator will be disabled and then enabled as part of the PCIe host

> initialization process and will be disabled when shutting down.

> 

> Signed-off-by: Quentin Schulz <quentin.schulz@free-electrons.com>


Waiting for ack from Richard or Lucas.

> ---

>  .../devicetree/bindings/pci/fsl,imx6q-pcie.txt     |  4 +++

>  drivers/pci/dwc/pci-imx6.c                         | 34 +++++++++++++++++++++-

>  2 files changed, 37 insertions(+), 1 deletion(-)

> 

> diff --git a/Documentation/devicetree/bindings/pci/fsl,imx6q-pcie.txt b/Documentation/devicetree/bindings/pci/fsl,imx6q-pcie.txt

> index e3d5680875b1..cf92d3ba5a26 100644

> --- a/Documentation/devicetree/bindings/pci/fsl,imx6q-pcie.txt

> +++ b/Documentation/devicetree/bindings/pci/fsl,imx6q-pcie.txt

> @@ -33,6 +33,10 @@ Optional properties:

>  - reset-gpio-active-high: If present then the reset sequence using the GPIO

>    specified in the "reset-gpio" property is reversed (H=reset state,

>    L=operation state).

> +- vpcie-supply: Should specify the regulator in charge of PCIe port power.

> +  The regulator will be enabled when initializing the PCIe host and

> +  disabled either as part of the init process or when shutting down the

> +  host.

>  

>  Additional required properties for imx6sx-pcie:

>  - clock names: Must include the following additional entries:

> diff --git a/drivers/pci/dwc/pci-imx6.c b/drivers/pci/dwc/pci-imx6.c

> index 19a289b8cc94..f9b7500c9aff 100644

> --- a/drivers/pci/dwc/pci-imx6.c

> +++ b/drivers/pci/dwc/pci-imx6.c

> @@ -24,6 +24,7 @@

>  #include <linux/pci.h>

>  #include <linux/platform_device.h>

>  #include <linux/regmap.h>

> +#include <linux/regulator/consumer.h>

>  #include <linux/resource.h>

>  #include <linux/signal.h>

>  #include <linux/types.h>

> @@ -59,6 +60,7 @@ struct imx6_pcie {

>  	u32			tx_swing_full;

>  	u32			tx_swing_low;

>  	int			link_gen;

> +	struct regulator	*vpcie;

>  };

>  

>  /* Parameters for the waiting for PCIe PHY PLL to lock on i.MX7 */

> @@ -310,6 +312,13 @@ static void imx6_pcie_assert_core_reset(struct imx6_pcie *imx6_pcie)

>  				   IMX6Q_GPR1_PCIE_REF_CLK_EN, 0 << 16);

>  		break;

>  	}

> +

> +	if (imx6_pcie->vpcie && regulator_is_enabled(imx6_pcie->vpcie) > 0) {

> +		int ret = regulator_disable(imx6_pcie->vpcie);

> +

> +		if (ret)

> +			pr_err("failed to disable vpcie regulator: %d\n", ret);

> +	}

>  }

>  

>  static int imx6_pcie_enable_ref_clk(struct imx6_pcie *imx6_pcie)

> @@ -376,10 +385,19 @@ static void imx6_pcie_deassert_core_reset(struct imx6_pcie *imx6_pcie)

>  	struct device *dev = pci->dev;

>  	int ret;

>  

> +	if (imx6_pcie->vpcie && !regulator_is_enabled(imx6_pcie->vpcie)) {

> +		ret = regulator_enable(imx6_pcie->vpcie);

> +		if (ret) {

> +			dev_err(dev, "failed to enable vpcie regulator: %d\n",

> +				ret);

> +			return;

> +		}

> +	}

> +

>  	ret = clk_prepare_enable(imx6_pcie->pcie_phy);

>  	if (ret) {

>  		dev_err(dev, "unable to enable pcie_phy clock\n");

> -		return;

> +		goto err_pcie_phy;

>  	}

>  

>  	ret = clk_prepare_enable(imx6_pcie->pcie_bus);

> @@ -439,6 +457,13 @@ static void imx6_pcie_deassert_core_reset(struct imx6_pcie *imx6_pcie)

>  	clk_disable_unprepare(imx6_pcie->pcie_bus);

>  err_pcie_bus:

>  	clk_disable_unprepare(imx6_pcie->pcie_phy);

> +err_pcie_phy:

> +	if (imx6_pcie->vpcie && regulator_is_enabled(imx6_pcie->vpcie) > 0) {

> +		ret = regulator_disable(imx6_pcie->vpcie);

> +		if (ret)

> +			dev_err(dev, "failed to disable vpcie regulator: %d\n",

> +				ret);

> +	}

>  }

>  

>  static void imx6_pcie_init_phy(struct imx6_pcie *imx6_pcie)

> @@ -802,6 +827,13 @@ static int imx6_pcie_probe(struct platform_device *pdev)

>  	if (ret)

>  		imx6_pcie->link_gen = 1;

>  

> +	imx6_pcie->vpcie = devm_regulator_get_optional(&pdev->dev, "vpcie");

> +	if (IS_ERR(imx6_pcie->vpcie)) {

> +		if (PTR_ERR(imx6_pcie->vpcie) == -EPROBE_DEFER)

> +			return -EPROBE_DEFER;

> +		imx6_pcie->vpcie = NULL;

> +	}

> +

>  	platform_set_drvdata(pdev, imx6_pcie);

>  

>  	ret = imx6_add_pcie_port(imx6_pcie, pdev);

> -- 

> 2.11.0

> 

> 

> _______________________________________________

> linux-arm-kernel mailing list

> linux-arm-kernel@lists.infradead.org

> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

--
To unsubscribe from this list: send the line "unsubscribe devicetree" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Richard Zhu June 16, 2017, 12:49 a.m. | #2
> -----Original Message-----

> From: Bjorn Helgaas [mailto:helgaas@kernel.org]

> Sent: Friday, June 16, 2017 5:06 AM

> To: Quentin Schulz <quentin.schulz@free-electrons.com>

> Cc: Richard Zhu <hongxing.zhu@nxp.com>; l.stach@pengutronix.de;

> bhelgaas@google.com; robh+dt@kernel.org; mark.rutland@arm.com;

> thomas.petazzoni@free-electrons.com; devicetree@vger.kernel.org; linux-

> pci@vger.kernel.org; linux-kernel@vger.kernel.org; linux-arm-

> kernel@lists.infradead.org

> Subject: Re: [PATCH] PCI: imx6: add regulator support

> 

> On Thu, Jun 08, 2017 at 10:07:42AM +0200, Quentin Schulz wrote:

> > Some boards might require to control a regulator to power the PCIe port.

> >

> > This adds support for an optional regulator defined in Device Tree

> > linked in the PCIe controller under `vpcie-supply`. If present, the

> > regulator will be disabled and then enabled as part of the PCIe host

> > initialization process and will be disabled when shutting down.

> >

> > Signed-off-by: Quentin Schulz <quentin.schulz@free-electrons.com>

> 

> Waiting for ack from Richard or Lucas.

[Zhu hongxing] Sorry to replay late.
This patch is okay for me.
Thanks.
Acked-by: Richard Zhu <hongxing.zhu@nxp.com>

> 

> > ---

> >  .../devicetree/bindings/pci/fsl,imx6q-pcie.txt     |  4 +++

> >  drivers/pci/dwc/pci-imx6.c                         | 34 +++++++++++++++++++++-

> >  2 files changed, 37 insertions(+), 1 deletion(-)

> >

> > diff --git a/Documentation/devicetree/bindings/pci/fsl,imx6q-pcie.txt

> > b/Documentation/devicetree/bindings/pci/fsl,imx6q-pcie.txt

> > index e3d5680875b1..cf92d3ba5a26 100644

> > --- a/Documentation/devicetree/bindings/pci/fsl,imx6q-pcie.txt

> > +++ b/Documentation/devicetree/bindings/pci/fsl,imx6q-pcie.txt

> > @@ -33,6 +33,10 @@ Optional properties:

> >  - reset-gpio-active-high: If present then the reset sequence using the

> GPIO

> >    specified in the "reset-gpio" property is reversed (H=reset state,

> >    L=operation state).

> > +- vpcie-supply: Should specify the regulator in charge of PCIe port power.

> > +  The regulator will be enabled when initializing the PCIe host and

> > +  disabled either as part of the init process or when shutting down

> > +the

> > +  host.

> >

> >  Additional required properties for imx6sx-pcie:

> >  - clock names: Must include the following additional entries:

> > diff --git a/drivers/pci/dwc/pci-imx6.c b/drivers/pci/dwc/pci-imx6.c

> > index 19a289b8cc94..f9b7500c9aff 100644

> > --- a/drivers/pci/dwc/pci-imx6.c

> > +++ b/drivers/pci/dwc/pci-imx6.c

> > @@ -24,6 +24,7 @@

> >  #include <linux/pci.h>

> >  #include <linux/platform_device.h>

> >  #include <linux/regmap.h>

> > +#include <linux/regulator/consumer.h>

> >  #include <linux/resource.h>

> >  #include <linux/signal.h>

> >  #include <linux/types.h>

> > @@ -59,6 +60,7 @@ struct imx6_pcie {

> >  	u32			tx_swing_full;

> >  	u32			tx_swing_low;

> >  	int			link_gen;

> > +	struct regulator	*vpcie;

> >  };

> >

> >  /* Parameters for the waiting for PCIe PHY PLL to lock on i.MX7 */ @@

> > -310,6 +312,13 @@ static void imx6_pcie_assert_core_reset(struct

> imx6_pcie *imx6_pcie)

> >  				   IMX6Q_GPR1_PCIE_REF_CLK_EN, 0 << 16);

> >  		break;

> >  	}

> > +

> > +	if (imx6_pcie->vpcie && regulator_is_enabled(imx6_pcie->vpcie) > 0)

> {

> > +		int ret = regulator_disable(imx6_pcie->vpcie);

> > +

> > +		if (ret)

> > +			pr_err("failed to disable vpcie regulator: %d\n", ret);

> > +	}

> >  }

> >

> >  static int imx6_pcie_enable_ref_clk(struct imx6_pcie *imx6_pcie) @@

> > -376,10 +385,19 @@ static void imx6_pcie_deassert_core_reset(struct

> imx6_pcie *imx6_pcie)

> >  	struct device *dev = pci->dev;

> >  	int ret;

> >

> > +	if (imx6_pcie->vpcie && !regulator_is_enabled(imx6_pcie->vpcie)) {

> > +		ret = regulator_enable(imx6_pcie->vpcie);

> > +		if (ret) {

> > +			dev_err(dev, "failed to enable vpcie regulator: %d\n",

> > +				ret);

> > +			return;

> > +		}

> > +	}

> > +

> >  	ret = clk_prepare_enable(imx6_pcie->pcie_phy);

> >  	if (ret) {

> >  		dev_err(dev, "unable to enable pcie_phy clock\n");

> > -		return;

> > +		goto err_pcie_phy;

> >  	}

> >

> >  	ret = clk_prepare_enable(imx6_pcie->pcie_bus);

> > @@ -439,6 +457,13 @@ static void imx6_pcie_deassert_core_reset(struct

> imx6_pcie *imx6_pcie)

> >  	clk_disable_unprepare(imx6_pcie->pcie_bus);

> >  err_pcie_bus:

> >  	clk_disable_unprepare(imx6_pcie->pcie_phy);

> > +err_pcie_phy:

> > +	if (imx6_pcie->vpcie && regulator_is_enabled(imx6_pcie->vpcie) > 0)

> {

> > +		ret = regulator_disable(imx6_pcie->vpcie);

> > +		if (ret)

> > +			dev_err(dev, "failed to disable vpcie regulator: %d\n",

> > +				ret);

> > +	}

> >  }

> >

> >  static void imx6_pcie_init_phy(struct imx6_pcie *imx6_pcie) @@ -802,6

> > +827,13 @@ static int imx6_pcie_probe(struct platform_device *pdev)

> >  	if (ret)

> >  		imx6_pcie->link_gen = 1;

> >

> > +	imx6_pcie->vpcie = devm_regulator_get_optional(&pdev->dev,

> "vpcie");

> > +	if (IS_ERR(imx6_pcie->vpcie)) {

> > +		if (PTR_ERR(imx6_pcie->vpcie) == -EPROBE_DEFER)

> > +			return -EPROBE_DEFER;

> > +		imx6_pcie->vpcie = NULL;

> > +	}

> > +

> >  	platform_set_drvdata(pdev, imx6_pcie);

> >

> >  	ret = imx6_add_pcie_port(imx6_pcie, pdev);

> > --

> > 2.11.0

> >

> >

> > _______________________________________________

> > linux-arm-kernel mailing list

> > linux-arm-kernel@lists.infradead.org

> > http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

--
To unsubscribe from this list: send the line "unsubscribe devicetree" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Bjorn Helgaas June 16, 2017, 4:58 p.m. | #3
On Thu, Jun 08, 2017 at 10:07:42AM +0200, Quentin Schulz wrote:
> Some boards might require to control a regulator to power the PCIe port.

> 

> This adds support for an optional regulator defined in Device Tree

> linked in the PCIe controller under `vpcie-supply`. If present, the

> regulator will be disabled and then enabled as part of the PCIe host

> initialization process and will be disabled when shutting down.

> 

> Signed-off-by: Quentin Schulz <quentin.schulz@free-electrons.com>


Applied with acks from Rob & Richard to pci/host-imx6 for v4.13, thanks!

I converted the pr_err() in imx6_pcie_assert_core_reset() to a dev_err().

> ---

>  .../devicetree/bindings/pci/fsl,imx6q-pcie.txt     |  4 +++

>  drivers/pci/dwc/pci-imx6.c                         | 34 +++++++++++++++++++++-

>  2 files changed, 37 insertions(+), 1 deletion(-)

> 

> diff --git a/Documentation/devicetree/bindings/pci/fsl,imx6q-pcie.txt b/Documentation/devicetree/bindings/pci/fsl,imx6q-pcie.txt

> index e3d5680875b1..cf92d3ba5a26 100644

> --- a/Documentation/devicetree/bindings/pci/fsl,imx6q-pcie.txt

> +++ b/Documentation/devicetree/bindings/pci/fsl,imx6q-pcie.txt

> @@ -33,6 +33,10 @@ Optional properties:

>  - reset-gpio-active-high: If present then the reset sequence using the GPIO

>    specified in the "reset-gpio" property is reversed (H=reset state,

>    L=operation state).

> +- vpcie-supply: Should specify the regulator in charge of PCIe port power.

> +  The regulator will be enabled when initializing the PCIe host and

> +  disabled either as part of the init process or when shutting down the

> +  host.

>  

>  Additional required properties for imx6sx-pcie:

>  - clock names: Must include the following additional entries:

> diff --git a/drivers/pci/dwc/pci-imx6.c b/drivers/pci/dwc/pci-imx6.c

> index 19a289b8cc94..f9b7500c9aff 100644

> --- a/drivers/pci/dwc/pci-imx6.c

> +++ b/drivers/pci/dwc/pci-imx6.c

> @@ -24,6 +24,7 @@

>  #include <linux/pci.h>

>  #include <linux/platform_device.h>

>  #include <linux/regmap.h>

> +#include <linux/regulator/consumer.h>

>  #include <linux/resource.h>

>  #include <linux/signal.h>

>  #include <linux/types.h>

> @@ -59,6 +60,7 @@ struct imx6_pcie {

>  	u32			tx_swing_full;

>  	u32			tx_swing_low;

>  	int			link_gen;

> +	struct regulator	*vpcie;

>  };

>  

>  /* Parameters for the waiting for PCIe PHY PLL to lock on i.MX7 */

> @@ -310,6 +312,13 @@ static void imx6_pcie_assert_core_reset(struct imx6_pcie *imx6_pcie)

>  				   IMX6Q_GPR1_PCIE_REF_CLK_EN, 0 << 16);

>  		break;

>  	}

> +

> +	if (imx6_pcie->vpcie && regulator_is_enabled(imx6_pcie->vpcie) > 0) {

> +		int ret = regulator_disable(imx6_pcie->vpcie);

> +

> +		if (ret)

> +			pr_err("failed to disable vpcie regulator: %d\n", ret);

> +	}

>  }

>  

>  static int imx6_pcie_enable_ref_clk(struct imx6_pcie *imx6_pcie)

> @@ -376,10 +385,19 @@ static void imx6_pcie_deassert_core_reset(struct imx6_pcie *imx6_pcie)

>  	struct device *dev = pci->dev;

>  	int ret;

>  

> +	if (imx6_pcie->vpcie && !regulator_is_enabled(imx6_pcie->vpcie)) {

> +		ret = regulator_enable(imx6_pcie->vpcie);

> +		if (ret) {

> +			dev_err(dev, "failed to enable vpcie regulator: %d\n",

> +				ret);

> +			return;

> +		}

> +	}

> +

>  	ret = clk_prepare_enable(imx6_pcie->pcie_phy);

>  	if (ret) {

>  		dev_err(dev, "unable to enable pcie_phy clock\n");

> -		return;

> +		goto err_pcie_phy;

>  	}

>  

>  	ret = clk_prepare_enable(imx6_pcie->pcie_bus);

> @@ -439,6 +457,13 @@ static void imx6_pcie_deassert_core_reset(struct imx6_pcie *imx6_pcie)

>  	clk_disable_unprepare(imx6_pcie->pcie_bus);

>  err_pcie_bus:

>  	clk_disable_unprepare(imx6_pcie->pcie_phy);

> +err_pcie_phy:

> +	if (imx6_pcie->vpcie && regulator_is_enabled(imx6_pcie->vpcie) > 0) {

> +		ret = regulator_disable(imx6_pcie->vpcie);

> +		if (ret)

> +			dev_err(dev, "failed to disable vpcie regulator: %d\n",

> +				ret);

> +	}

>  }

>  

>  static void imx6_pcie_init_phy(struct imx6_pcie *imx6_pcie)

> @@ -802,6 +827,13 @@ static int imx6_pcie_probe(struct platform_device *pdev)

>  	if (ret)

>  		imx6_pcie->link_gen = 1;

>  

> +	imx6_pcie->vpcie = devm_regulator_get_optional(&pdev->dev, "vpcie");

> +	if (IS_ERR(imx6_pcie->vpcie)) {

> +		if (PTR_ERR(imx6_pcie->vpcie) == -EPROBE_DEFER)

> +			return -EPROBE_DEFER;

> +		imx6_pcie->vpcie = NULL;

> +	}

> +

>  	platform_set_drvdata(pdev, imx6_pcie);

>  

>  	ret = imx6_add_pcie_port(imx6_pcie, pdev);

> -- 

> 2.11.0

> 

> 

> _______________________________________________

> linux-arm-kernel mailing list

> linux-arm-kernel@lists.infradead.org

> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

--
To unsubscribe from this list: send the line "unsubscribe devicetree" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Patch hide | download patch | download mbox

diff --git a/Documentation/devicetree/bindings/pci/fsl,imx6q-pcie.txt b/Documentation/devicetree/bindings/pci/fsl,imx6q-pcie.txt
index e3d5680875b1..cf92d3ba5a26 100644
--- a/Documentation/devicetree/bindings/pci/fsl,imx6q-pcie.txt
+++ b/Documentation/devicetree/bindings/pci/fsl,imx6q-pcie.txt
@@ -33,6 +33,10 @@  Optional properties:
 - reset-gpio-active-high: If present then the reset sequence using the GPIO
   specified in the "reset-gpio" property is reversed (H=reset state,
   L=operation state).
+- vpcie-supply: Should specify the regulator in charge of PCIe port power.
+  The regulator will be enabled when initializing the PCIe host and
+  disabled either as part of the init process or when shutting down the
+  host.
 
 Additional required properties for imx6sx-pcie:
 - clock names: Must include the following additional entries:
diff --git a/drivers/pci/dwc/pci-imx6.c b/drivers/pci/dwc/pci-imx6.c
index 19a289b8cc94..f9b7500c9aff 100644
--- a/drivers/pci/dwc/pci-imx6.c
+++ b/drivers/pci/dwc/pci-imx6.c
@@ -24,6 +24,7 @@ 
 #include <linux/pci.h>
 #include <linux/platform_device.h>
 #include <linux/regmap.h>
+#include <linux/regulator/consumer.h>
 #include <linux/resource.h>
 #include <linux/signal.h>
 #include <linux/types.h>
@@ -59,6 +60,7 @@  struct imx6_pcie {
 	u32			tx_swing_full;
 	u32			tx_swing_low;
 	int			link_gen;
+	struct regulator	*vpcie;
 };
 
 /* Parameters for the waiting for PCIe PHY PLL to lock on i.MX7 */
@@ -310,6 +312,13 @@  static void imx6_pcie_assert_core_reset(struct imx6_pcie *imx6_pcie)
 				   IMX6Q_GPR1_PCIE_REF_CLK_EN, 0 << 16);
 		break;
 	}
+
+	if (imx6_pcie->vpcie && regulator_is_enabled(imx6_pcie->vpcie) > 0) {
+		int ret = regulator_disable(imx6_pcie->vpcie);
+
+		if (ret)
+			pr_err("failed to disable vpcie regulator: %d\n", ret);
+	}
 }
 
 static int imx6_pcie_enable_ref_clk(struct imx6_pcie *imx6_pcie)
@@ -376,10 +385,19 @@  static void imx6_pcie_deassert_core_reset(struct imx6_pcie *imx6_pcie)
 	struct device *dev = pci->dev;
 	int ret;
 
+	if (imx6_pcie->vpcie && !regulator_is_enabled(imx6_pcie->vpcie)) {
+		ret = regulator_enable(imx6_pcie->vpcie);
+		if (ret) {
+			dev_err(dev, "failed to enable vpcie regulator: %d\n",
+				ret);
+			return;
+		}
+	}
+
 	ret = clk_prepare_enable(imx6_pcie->pcie_phy);
 	if (ret) {
 		dev_err(dev, "unable to enable pcie_phy clock\n");
-		return;
+		goto err_pcie_phy;
 	}
 
 	ret = clk_prepare_enable(imx6_pcie->pcie_bus);
@@ -439,6 +457,13 @@  static void imx6_pcie_deassert_core_reset(struct imx6_pcie *imx6_pcie)
 	clk_disable_unprepare(imx6_pcie->pcie_bus);
 err_pcie_bus:
 	clk_disable_unprepare(imx6_pcie->pcie_phy);
+err_pcie_phy:
+	if (imx6_pcie->vpcie && regulator_is_enabled(imx6_pcie->vpcie) > 0) {
+		ret = regulator_disable(imx6_pcie->vpcie);
+		if (ret)
+			dev_err(dev, "failed to disable vpcie regulator: %d\n",
+				ret);
+	}
 }
 
 static void imx6_pcie_init_phy(struct imx6_pcie *imx6_pcie)
@@ -802,6 +827,13 @@  static int imx6_pcie_probe(struct platform_device *pdev)
 	if (ret)
 		imx6_pcie->link_gen = 1;
 
+	imx6_pcie->vpcie = devm_regulator_get_optional(&pdev->dev, "vpcie");
+	if (IS_ERR(imx6_pcie->vpcie)) {
+		if (PTR_ERR(imx6_pcie->vpcie) == -EPROBE_DEFER)
+			return -EPROBE_DEFER;
+		imx6_pcie->vpcie = NULL;
+	}
+
 	platform_set_drvdata(pdev, imx6_pcie);
 
 	ret = imx6_add_pcie_port(imx6_pcie, pdev);