[RESEND] PCI: imx: Initial imx7d pm support

[RESEND] PCI: imx: Initial imx7d pm support

[Leonard Crestez]

On imx7d the pcie-phy power domain is turned off in suspend and this can
make the system hang after resume when attempting any read from PCI.

Fix this by adding minimal suspend/resume code from the nxp internal
tree. This will prepare for powering down on suspend and reset the block
on resume.

Code is only for imx7d but a very similar sequence can be used for
other socs.

The original author is mostly Richard Zhu <hongxing.zhu@nxp.com>, this
patch adjusts the code to the upstream imx7d implemention using reset
controls and power domains.

Signed-off-by: Leonard Crestez <leonard.crestez@nxp.com>
Reviewed-by: Lucas Stach <l.stach@pengutronix.de>
---
 drivers/pci/controller/dwc/pci-imx6.c | 97 +++++++++++++++++++++++++--
 1 file changed, 92 insertions(+), 5 deletions(-)

Resending after RC1 as suggested here: https://lkml.org/lkml/2018/8/8/496

This was initially sent together with a dts fix, that was already
accepted by Shawn: https://lkml.org/lkml/2018/8/21/529

Some dependencies in this area are complicated but as far as I know
including this patch without others should not break anything that was
not already broken. Since this is a patch for something that has never
worked before it should be treated as a feature not a bugfix.

I have a few other patches for imx pci but it's better to deal with them
separately. This initial patch adding suspend support is useful by
itself.

diff --git a/drivers/pci/controller/dwc/pci-imx6.c b/drivers/pci/controller/dwc/pci-imx6.c
index 4a9a673b4777..65b6d1015723 100644
--- a/drivers/pci/controller/dwc/pci-imx6.c
+++ b/drivers/pci/controller/dwc/pci-imx6.c
@@ -540,10 +540,28 @@ static int imx6_pcie_wait_for_speed_change(struct imx6_pcie *imx6_pcie)
 
 	dev_err(dev, "Speed change timeout\n");
 	return -EINVAL;
 }
 
+static void imx6_pcie_ltssm_enable(struct device *dev)
+{
+	struct imx6_pcie *imx6_pcie = dev_get_drvdata(dev);
+
+	switch (imx6_pcie->variant) {
+	case IMX6Q:
+	case IMX6SX:
+	case IMX6QP:
+		regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12,
+				   IMX6Q_GPR12_PCIE_CTL_2,
+				   IMX6Q_GPR12_PCIE_CTL_2);
+		break;
+	case IMX7D:
+		reset_control_deassert(imx6_pcie->apps_reset);
+		break;
+	}
+}
+
 static int imx6_pcie_establish_link(struct imx6_pcie *imx6_pcie)
 {
 	struct dw_pcie *pci = imx6_pcie->pci;
 	struct device *dev = pci->dev;
 	u32 tmp;
@@ -558,15 +576,11 @@ static int imx6_pcie_establish_link(struct imx6_pcie *imx6_pcie)
 	tmp &= ~PCIE_RC_LCR_MAX_LINK_SPEEDS_MASK;
 	tmp |= PCIE_RC_LCR_MAX_LINK_SPEEDS_GEN1;
 	dw_pcie_writel_dbi(pci, PCIE_RC_LCR, tmp);
 
 	/* Start LTSSM. */
-	if (imx6_pcie->variant == IMX7D)
-		reset_control_deassert(imx6_pcie->apps_reset);
-	else
-		regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12,
-				   IMX6Q_GPR12_PCIE_CTL_2, 1 << 10);
+	imx6_pcie_ltssm_enable(dev);
 
 	ret = imx6_pcie_wait_for_link(imx6_pcie);
 	if (ret)
 		goto err_reset_phy;
 
@@ -680,10 +694,82 @@ static int imx6_add_pcie_port(struct imx6_pcie *imx6_pcie,
 
 static const struct dw_pcie_ops dw_pcie_ops = {
 	.link_up = imx6_pcie_link_up,
 };
 
+#ifdef CONFIG_PM_SLEEP
+static void imx6_pcie_ltssm_disable(struct device *dev)
+{
+	struct imx6_pcie *imx6_pcie = dev_get_drvdata(dev);
+
+	switch (imx6_pcie->variant) {
+	case IMX6SX:
+	case IMX6QP:
+		regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12,
+				   IMX6Q_GPR12_PCIE_CTL_2, 0);
+		break;
+	case IMX7D:
+		reset_control_assert(imx6_pcie->apps_reset);
+		break;
+	default:
+		dev_err(dev, "ltssm_disable not supported\n");
+	}
+}
+
+static void imx6_pcie_clk_disable(struct imx6_pcie *imx6_pcie)
+{
+	clk_disable_unprepare(imx6_pcie->pcie);
+	clk_disable_unprepare(imx6_pcie->pcie_phy);
+	clk_disable_unprepare(imx6_pcie->pcie_bus);
+
+	if (imx6_pcie->variant == IMX7D) {
+		regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12,
+				   IMX7D_GPR12_PCIE_PHY_REFCLK_SEL,
+				   IMX7D_GPR12_PCIE_PHY_REFCLK_SEL);
+	}
+}
+
+static int imx6_pcie_suspend_noirq(struct device *dev)
+{
+	struct imx6_pcie *imx6_pcie = dev_get_drvdata(dev);
+
+	if (imx6_pcie->variant != IMX7D)
+		return 0;
+
+	imx6_pcie_clk_disable(imx6_pcie);
+	imx6_pcie_ltssm_disable(dev);
+
+	return 0;
+}
+
+static int imx6_pcie_resume_noirq(struct device *dev)
+{
+	int ret;
+	struct imx6_pcie *imx6_pcie = dev_get_drvdata(dev);
+	struct pcie_port *pp = &imx6_pcie->pci->pp;
+
+	if (imx6_pcie->variant != IMX7D)
+		return 0;
+
+	imx6_pcie_assert_core_reset(imx6_pcie);
+	imx6_pcie_init_phy(imx6_pcie);
+	imx6_pcie_deassert_core_reset(imx6_pcie);
+	dw_pcie_setup_rc(pp);
+
+	ret = imx6_pcie_establish_link(imx6_pcie);
+	if (ret < 0)
+		dev_info(dev, "pcie link is down after resume.\n");
+
+	return 0;
+}
+#endif
+
+static const struct dev_pm_ops imx6_pcie_pm_ops = {
+	SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(imx6_pcie_suspend_noirq,
+				      imx6_pcie_resume_noirq)
+};
+
 static int imx6_pcie_probe(struct platform_device *pdev)
 {
 	struct device *dev = &pdev->dev;
 	struct dw_pcie *pci;
 	struct imx6_pcie *imx6_pcie;
@@ -846,10 +932,11 @@ static const struct of_device_id imx6_pcie_of_match[] = {
 static struct platform_driver imx6_pcie_driver = {
 	.driver = {
 		.name	= "imx6q-pcie",
 		.of_match_table = imx6_pcie_of_match,
 		.suppress_bind_attrs = true,
+		.pm = &imx6_pcie_pm_ops,
 	},
 	.probe    = imx6_pcie_probe,
 	.shutdown = imx6_pcie_shutdown,
 };
 
-- 
2.17.1

Re: [RESEND] PCI: imx: Initial imx7d pm support

[Lorenzo Pieralisi]

On Mon, Aug 27, 2018 at 02:28:37PM +0300, Leonard Crestez wrote:
> On imx7d the pcie-phy power domain is turned off in suspend and this can
> make the system hang after resume when attempting any read from PCI.
> 
> Fix this by adding minimal suspend/resume code from the nxp internal
> tree. This will prepare for powering down on suspend and reset the block
> on resume.
> 
> Code is only for imx7d but a very similar sequence can be used for
> other socs.
> 
> The original author is mostly Richard Zhu <hongxing.zhu@nxp.com>, this
> patch adjusts the code to the upstream imx7d implemention using reset
> controls and power domains.

I will add a Suggested-by: replacing this paragraph, it is always better
to add proper tags rather than credit hidden in commit logs messages.

> Signed-off-by: Leonard Crestez <leonard.crestez@nxp.com>
> Reviewed-by: Lucas Stach <l.stach@pengutronix.de>
> ---
>  drivers/pci/controller/dwc/pci-imx6.c | 97 +++++++++++++++++++++++++--
>  1 file changed, 92 insertions(+), 5 deletions(-)
> 
> Resending after RC1 as suggested here: https://lkml.org/lkml/2018/8/8/496
> 
> This was initially sent together with a dts fix, that was already
> accepted by Shawn: https://lkml.org/lkml/2018/8/21/529
> 
> Some dependencies in this area are complicated but as far as I know
> including this patch without others should not break anything that was
> not already broken. Since this is a patch for something that has never
> worked before it should be treated as a feature not a bugfix.

Ok, so I consider this v4.20 material, please shout if it has to be
sent as a fix, I do not think so given what we discussed above.

Lorenzo

> I have a few other patches for imx pci but it's better to deal with them
> separately. This initial patch adding suspend support is useful by
> itself.
> 
> diff --git a/drivers/pci/controller/dwc/pci-imx6.c b/drivers/pci/controller/dwc/pci-imx6.c
> index 4a9a673b4777..65b6d1015723 100644
> --- a/drivers/pci/controller/dwc/pci-imx6.c
> +++ b/drivers/pci/controller/dwc/pci-imx6.c
> @@ -540,10 +540,28 @@ static int imx6_pcie_wait_for_speed_change(struct imx6_pcie *imx6_pcie)
>  
>  	dev_err(dev, "Speed change timeout\n");
>  	return -EINVAL;
>  }
>  
> +static void imx6_pcie_ltssm_enable(struct device *dev)
> +{
> +	struct imx6_pcie *imx6_pcie = dev_get_drvdata(dev);
> +
> +	switch (imx6_pcie->variant) {
> +	case IMX6Q:
> +	case IMX6SX:
> +	case IMX6QP:
> +		regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12,
> +				   IMX6Q_GPR12_PCIE_CTL_2,
> +				   IMX6Q_GPR12_PCIE_CTL_2);
> +		break;
> +	case IMX7D:
> +		reset_control_deassert(imx6_pcie->apps_reset);
> +		break;
> +	}
> +}
> +
>  static int imx6_pcie_establish_link(struct imx6_pcie *imx6_pcie)
>  {
>  	struct dw_pcie *pci = imx6_pcie->pci;
>  	struct device *dev = pci->dev;
>  	u32 tmp;
> @@ -558,15 +576,11 @@ static int imx6_pcie_establish_link(struct imx6_pcie *imx6_pcie)
>  	tmp &= ~PCIE_RC_LCR_MAX_LINK_SPEEDS_MASK;
>  	tmp |= PCIE_RC_LCR_MAX_LINK_SPEEDS_GEN1;
>  	dw_pcie_writel_dbi(pci, PCIE_RC_LCR, tmp);
>  
>  	/* Start LTSSM. */
> -	if (imx6_pcie->variant == IMX7D)
> -		reset_control_deassert(imx6_pcie->apps_reset);
> -	else
> -		regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12,
> -				   IMX6Q_GPR12_PCIE_CTL_2, 1 << 10);
> +	imx6_pcie_ltssm_enable(dev);
>  
>  	ret = imx6_pcie_wait_for_link(imx6_pcie);
>  	if (ret)
>  		goto err_reset_phy;
>  
> @@ -680,10 +694,82 @@ static int imx6_add_pcie_port(struct imx6_pcie *imx6_pcie,
>  
>  static const struct dw_pcie_ops dw_pcie_ops = {
>  	.link_up = imx6_pcie_link_up,
>  };
>  
> +#ifdef CONFIG_PM_SLEEP
> +static void imx6_pcie_ltssm_disable(struct device *dev)
> +{
> +	struct imx6_pcie *imx6_pcie = dev_get_drvdata(dev);
> +
> +	switch (imx6_pcie->variant) {
> +	case IMX6SX:
> +	case IMX6QP:
> +		regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12,
> +				   IMX6Q_GPR12_PCIE_CTL_2, 0);
> +		break;
> +	case IMX7D:
> +		reset_control_assert(imx6_pcie->apps_reset);
> +		break;
> +	default:
> +		dev_err(dev, "ltssm_disable not supported\n");
> +	}
> +}
> +
> +static void imx6_pcie_clk_disable(struct imx6_pcie *imx6_pcie)
> +{
> +	clk_disable_unprepare(imx6_pcie->pcie);
> +	clk_disable_unprepare(imx6_pcie->pcie_phy);
> +	clk_disable_unprepare(imx6_pcie->pcie_bus);
> +
> +	if (imx6_pcie->variant == IMX7D) {
> +		regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12,
> +				   IMX7D_GPR12_PCIE_PHY_REFCLK_SEL,
> +				   IMX7D_GPR12_PCIE_PHY_REFCLK_SEL);
> +	}
> +}
> +
> +static int imx6_pcie_suspend_noirq(struct device *dev)
> +{
> +	struct imx6_pcie *imx6_pcie = dev_get_drvdata(dev);
> +
> +	if (imx6_pcie->variant != IMX7D)
> +		return 0;
> +
> +	imx6_pcie_clk_disable(imx6_pcie);
> +	imx6_pcie_ltssm_disable(dev);
> +
> +	return 0;
> +}
> +
> +static int imx6_pcie_resume_noirq(struct device *dev)
> +{
> +	int ret;
> +	struct imx6_pcie *imx6_pcie = dev_get_drvdata(dev);
> +	struct pcie_port *pp = &imx6_pcie->pci->pp;
> +
> +	if (imx6_pcie->variant != IMX7D)
> +		return 0;
> +
> +	imx6_pcie_assert_core_reset(imx6_pcie);
> +	imx6_pcie_init_phy(imx6_pcie);
> +	imx6_pcie_deassert_core_reset(imx6_pcie);
> +	dw_pcie_setup_rc(pp);
> +
> +	ret = imx6_pcie_establish_link(imx6_pcie);
> +	if (ret < 0)
> +		dev_info(dev, "pcie link is down after resume.\n");
> +
> +	return 0;
> +}
> +#endif
> +
> +static const struct dev_pm_ops imx6_pcie_pm_ops = {
> +	SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(imx6_pcie_suspend_noirq,
> +				      imx6_pcie_resume_noirq)
> +};
> +
>  static int imx6_pcie_probe(struct platform_device *pdev)
>  {
>  	struct device *dev = &pdev->dev;
>  	struct dw_pcie *pci;
>  	struct imx6_pcie *imx6_pcie;
> @@ -846,10 +932,11 @@ static const struct of_device_id imx6_pcie_of_match[] = {
>  static struct platform_driver imx6_pcie_driver = {
>  	.driver = {
>  		.name	= "imx6q-pcie",
>  		.of_match_table = imx6_pcie_of_match,
>  		.suppress_bind_attrs = true,
> +		.pm = &imx6_pcie_pm_ops,
>  	},
>  	.probe    = imx6_pcie_probe,
>  	.shutdown = imx6_pcie_shutdown,
>  };
>  
> -- 
> 2.17.1
> 

Re: [RESEND] PCI: imx: Initial imx7d pm support

[Leonard Crestez]

On Tue, 2018-08-28 at 11:07 +0100, Lorenzo Pieralisi wrote:
> On Mon, Aug 27, 2018 at 02:28:37PM +0300, Leonard Crestez wrote:
> > On imx7d the pcie-phy power domain is turned off in suspend and this can
> > make the system hang after resume when attempting any read from PCI.
> > 
> > Fix this by adding minimal suspend/resume code from the nxp internal
> > tree. This will prepare for powering down on suspend and reset the block
> > on resume.
> > 
> > Code is only for imx7d but a very similar sequence can be used for
> > other socs.
> > 
> > The original author is mostly Richard Zhu <hongxing.zhu@nxp.com>, this
> > patch adjusts the code to the upstream imx7d implemention using reset
> > controls and power domains.
> 
> I will add a Suggested-by: replacing this paragraph, it is always better
> to add proper tags rather than credit hidden in commit logs messages.

Isn't "Originally-by:" a better tag for this?

> > Some dependencies in this area are complicated but as far as I know
> > including this patch without others should not break anything that was
> > not already broken. Since this is a patch for something that has never
> > worked before it should be treated as a feature not a bugfix.
> 
> Ok, so I consider this v4.20 material, please shout if it has to be
> sent as a fix, I do not think so given what we discussed above.

Thanks!

Re: [RESEND] PCI: imx: Initial imx7d pm support

[Lorenzo Pieralisi]

On Tue, Aug 28, 2018 at 01:00:02PM +0000, Leonard Crestez wrote:
> On Tue, 2018-08-28 at 11:07 +0100, Lorenzo Pieralisi wrote:
> > On Mon, Aug 27, 2018 at 02:28:37PM +0300, Leonard Crestez wrote:
> > > On imx7d the pcie-phy power domain is turned off in suspend and this can
> > > make the system hang after resume when attempting any read from PCI.
> > > 
> > > Fix this by adding minimal suspend/resume code from the nxp internal
> > > tree. This will prepare for powering down on suspend and reset the block
> > > on resume.
> > > 
> > > Code is only for imx7d but a very similar sequence can be used for
> > > other socs.
> > > 
> > > The original author is mostly Richard Zhu <hongxing.zhu@nxp.com>, this
> > > patch adjusts the code to the upstream imx7d implemention using reset
> > > controls and power domains.
> > 
> > I will add a Suggested-by: replacing this paragraph, it is always better
> > to add proper tags rather than credit hidden in commit logs messages.
> 
> Isn't "Originally-by:" a better tag for this?

We can add that, yes or add Richard as patch author, as you prefer to
give him credit.

Lorenzo

Re: [RESEND] PCI: imx: Initial imx7d pm support

[Leonard Crestez]

On Tue, 2018-08-28 at 15:55 +0100, Lorenzo Pieralisi wrote:
> On Tue, Aug 28, 2018 at 01:00:02PM +0000, Leonard Crestez wrote:
> > On Tue, 2018-08-28 at 11:07 +0100, Lorenzo Pieralisi wrote:
> > > On Mon, Aug 27, 2018 at 02:28:37PM +0300, Leonard Crestez wrote:
> > > > On imx7d the pcie-phy power domain is turned off in suspend and this can
> > > > make the system hang after resume when attempting any read from PCI.
> > > > 
> > > > Fix this by adding minimal suspend/resume code from the nxp internal
> > > > tree. This will prepare for powering down on suspend and reset the block
> > > > on resume.
> > > > 
> > > > Code is only for imx7d but a very similar sequence can be used for
> > > > other socs.
> > > > 
> > > > The original author is mostly Richard Zhu <hongxing.zhu@nxp.com>, this
> > > > patch adjusts the code to the upstream imx7d implemention using reset
> > > > controls and power domains.
> > > 
> > > I will add a Suggested-by: replacing this paragraph, it is always better
> > > to add proper tags rather than credit hidden in commit logs messages.
> > 
> > Isn't "Originally-by:" a better tag for this?
> 
> We can add that, yes or add Richard as patch author, as you prefer to
> give him credit.

I think "Originally-by:" is a better fit because there is no
clear correspondence with patches from the vendor tree.

--
Regards,
Leonard

Re: [RESEND] PCI: imx: Initial imx7d pm support

[Lorenzo Pieralisi]

On Mon, Aug 27, 2018 at 02:28:37PM +0300, Leonard Crestez wrote:
> On imx7d the pcie-phy power domain is turned off in suspend and this can
> make the system hang after resume when attempting any read from PCI.
> 
> Fix this by adding minimal suspend/resume code from the nxp internal
> tree. This will prepare for powering down on suspend and reset the block
> on resume.
> 
> Code is only for imx7d but a very similar sequence can be used for
> other socs.
> 
> The original author is mostly Richard Zhu <hongxing.zhu@nxp.com>, this
> patch adjusts the code to the upstream imx7d implemention using reset
> controls and power domains.
> 
> Signed-off-by: Leonard Crestez <leonard.crestez@nxp.com>
> Reviewed-by: Lucas Stach <l.stach@pengutronix.de>
> ---
>  drivers/pci/controller/dwc/pci-imx6.c | 97 +++++++++++++++++++++++++--
>  1 file changed, 92 insertions(+), 5 deletions(-)

Applied to pci/dwc for v4.20, thanks.

Lorenzo

> Resending after RC1 as suggested here: https://lkml.org/lkml/2018/8/8/496
> 
> This was initially sent together with a dts fix, that was already
> accepted by Shawn: https://lkml.org/lkml/2018/8/21/529
> 
> Some dependencies in this area are complicated but as far as I know
> including this patch without others should not break anything that was
> not already broken. Since this is a patch for something that has never
> worked before it should be treated as a feature not a bugfix.
> 
> I have a few other patches for imx pci but it's better to deal with them
> separately. This initial patch adding suspend support is useful by
> itself.
> 
> diff --git a/drivers/pci/controller/dwc/pci-imx6.c b/drivers/pci/controller/dwc/pci-imx6.c
> index 4a9a673b4777..65b6d1015723 100644
> --- a/drivers/pci/controller/dwc/pci-imx6.c
> +++ b/drivers/pci/controller/dwc/pci-imx6.c
> @@ -540,10 +540,28 @@ static int imx6_pcie_wait_for_speed_change(struct imx6_pcie *imx6_pcie)
>  
>  	dev_err(dev, "Speed change timeout\n");
>  	return -EINVAL;
>  }
>  
> +static void imx6_pcie_ltssm_enable(struct device *dev)
> +{
> +	struct imx6_pcie *imx6_pcie = dev_get_drvdata(dev);
> +
> +	switch (imx6_pcie->variant) {
> +	case IMX6Q:
> +	case IMX6SX:
> +	case IMX6QP:
> +		regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12,
> +				   IMX6Q_GPR12_PCIE_CTL_2,
> +				   IMX6Q_GPR12_PCIE_CTL_2);
> +		break;
> +	case IMX7D:
> +		reset_control_deassert(imx6_pcie->apps_reset);
> +		break;
> +	}
> +}
> +
>  static int imx6_pcie_establish_link(struct imx6_pcie *imx6_pcie)
>  {
>  	struct dw_pcie *pci = imx6_pcie->pci;
>  	struct device *dev = pci->dev;
>  	u32 tmp;
> @@ -558,15 +576,11 @@ static int imx6_pcie_establish_link(struct imx6_pcie *imx6_pcie)
>  	tmp &= ~PCIE_RC_LCR_MAX_LINK_SPEEDS_MASK;
>  	tmp |= PCIE_RC_LCR_MAX_LINK_SPEEDS_GEN1;
>  	dw_pcie_writel_dbi(pci, PCIE_RC_LCR, tmp);
>  
>  	/* Start LTSSM. */
> -	if (imx6_pcie->variant == IMX7D)
> -		reset_control_deassert(imx6_pcie->apps_reset);
> -	else
> -		regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12,
> -				   IMX6Q_GPR12_PCIE_CTL_2, 1 << 10);
> +	imx6_pcie_ltssm_enable(dev);
>  
>  	ret = imx6_pcie_wait_for_link(imx6_pcie);
>  	if (ret)
>  		goto err_reset_phy;
>  
> @@ -680,10 +694,82 @@ static int imx6_add_pcie_port(struct imx6_pcie *imx6_pcie,
>  
>  static const struct dw_pcie_ops dw_pcie_ops = {
>  	.link_up = imx6_pcie_link_up,
>  };
>  
> +#ifdef CONFIG_PM_SLEEP
> +static void imx6_pcie_ltssm_disable(struct device *dev)
> +{
> +	struct imx6_pcie *imx6_pcie = dev_get_drvdata(dev);
> +
> +	switch (imx6_pcie->variant) {
> +	case IMX6SX:
> +	case IMX6QP:
> +		regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12,
> +				   IMX6Q_GPR12_PCIE_CTL_2, 0);
> +		break;
> +	case IMX7D:
> +		reset_control_assert(imx6_pcie->apps_reset);
> +		break;
> +	default:
> +		dev_err(dev, "ltssm_disable not supported\n");
> +	}
> +}
> +
> +static void imx6_pcie_clk_disable(struct imx6_pcie *imx6_pcie)
> +{
> +	clk_disable_unprepare(imx6_pcie->pcie);
> +	clk_disable_unprepare(imx6_pcie->pcie_phy);
> +	clk_disable_unprepare(imx6_pcie->pcie_bus);
> +
> +	if (imx6_pcie->variant == IMX7D) {
> +		regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12,
> +				   IMX7D_GPR12_PCIE_PHY_REFCLK_SEL,
> +				   IMX7D_GPR12_PCIE_PHY_REFCLK_SEL);
> +	}
> +}
> +
> +static int imx6_pcie_suspend_noirq(struct device *dev)
> +{
> +	struct imx6_pcie *imx6_pcie = dev_get_drvdata(dev);
> +
> +	if (imx6_pcie->variant != IMX7D)
> +		return 0;
> +
> +	imx6_pcie_clk_disable(imx6_pcie);
> +	imx6_pcie_ltssm_disable(dev);
> +
> +	return 0;
> +}
> +
> +static int imx6_pcie_resume_noirq(struct device *dev)
> +{
> +	int ret;
> +	struct imx6_pcie *imx6_pcie = dev_get_drvdata(dev);
> +	struct pcie_port *pp = &imx6_pcie->pci->pp;
> +
> +	if (imx6_pcie->variant != IMX7D)
> +		return 0;
> +
> +	imx6_pcie_assert_core_reset(imx6_pcie);
> +	imx6_pcie_init_phy(imx6_pcie);
> +	imx6_pcie_deassert_core_reset(imx6_pcie);
> +	dw_pcie_setup_rc(pp);
> +
> +	ret = imx6_pcie_establish_link(imx6_pcie);
> +	if (ret < 0)
> +		dev_info(dev, "pcie link is down after resume.\n");
> +
> +	return 0;
> +}
> +#endif
> +
> +static const struct dev_pm_ops imx6_pcie_pm_ops = {
> +	SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(imx6_pcie_suspend_noirq,
> +				      imx6_pcie_resume_noirq)
> +};
> +
>  static int imx6_pcie_probe(struct platform_device *pdev)
>  {
>  	struct device *dev = &pdev->dev;
>  	struct dw_pcie *pci;
>  	struct imx6_pcie *imx6_pcie;
> @@ -846,10 +932,11 @@ static const struct of_device_id imx6_pcie_of_match[] = {
>  static struct platform_driver imx6_pcie_driver = {
>  	.driver = {
>  		.name	= "imx6q-pcie",
>  		.of_match_table = imx6_pcie_of_match,
>  		.suppress_bind_attrs = true,
> +		.pm = &imx6_pcie_pm_ops,
>  	},
>  	.probe    = imx6_pcie_probe,
>  	.shutdown = imx6_pcie_shutdown,
>  };
>  
> -- 
> 2.17.1
>