diff mbox series

[v2,6/6] PCI: imx6: Save and restore the LUT setting for i.MX95 PCIe

Message ID 20250326075915.4073725-7-hongxing.zhu@nxp.com (mailing list archive)
State New
Headers show
Series Add some enhancements for i.MX95 PCIe | expand

Commit Message

Richard Zhu March 26, 2025, 7:59 a.m. UTC
LUT(look up table) setting would be lost during PCIe suspend on i.MX95.

To let i.MX95 PCIe PM work fine, save and restore the LUT setting in
suspend and resume operations.

Signed-off-by: Richard Zhu <hongxing.zhu@nxp.com>
---
 drivers/pci/controller/dwc/pci-imx6.c | 47 +++++++++++++++++++++++++++
 1 file changed, 47 insertions(+)

Comments

Frank Li March 26, 2025, 3 p.m. UTC | #1
On Wed, Mar 26, 2025 at 03:59:15PM +0800, Richard Zhu wrote:
> LUT(look up table) setting would be lost during PCIe suspend on i.MX95.

The look up table (LUT) ...

>
> To let i.MX95 PCIe PM work fine, save and restore the LUT setting in
> suspend and resume operations.

To ensure proper functionality after resume, save and restore ...

Frank

>
> Signed-off-by: Richard Zhu <hongxing.zhu@nxp.com>
> ---
>  drivers/pci/controller/dwc/pci-imx6.c | 47 +++++++++++++++++++++++++++
>  1 file changed, 47 insertions(+)
>
> diff --git a/drivers/pci/controller/dwc/pci-imx6.c b/drivers/pci/controller/dwc/pci-imx6.c
> index 1c8834fbcfd5..dc98a04c2956 100644
> --- a/drivers/pci/controller/dwc/pci-imx6.c
> +++ b/drivers/pci/controller/dwc/pci-imx6.c
> @@ -137,6 +137,11 @@ struct imx_pcie_drvdata {
>  	const struct dw_pcie_host_ops *ops;
>  };
>
> +struct imx_lut_data {
> +	u32 data1;
> +	u32 data2;
> +};
> +
>  struct imx_pcie {
>  	struct dw_pcie		*pci;
>  	struct gpio_desc	*reset_gpiod;
> @@ -156,6 +161,8 @@ struct imx_pcie {
>  	struct regulator	*vph;
>  	void __iomem		*phy_base;
>
> +	/* LUT data for pcie */
> +	struct imx_lut_data	luts[IMX95_MAX_LUT];
>  	/* power domain for pcie */
>  	struct device		*pd_pcie;
>  	/* power domain for pcie phy */
> @@ -1507,6 +1514,42 @@ static void imx_pcie_msi_save_restore(struct imx_pcie *imx_pcie, bool save)
>  	}
>  }
>
> +static void imx_pcie_lut_save(struct imx_pcie *imx_pcie)
> +{
> +	u32 data1, data2;
> +	int i;
> +
> +	for (i = 0; i < IMX95_MAX_LUT; i++) {
> +		regmap_write(imx_pcie->iomuxc_gpr, IMX95_PE0_LUT_ACSCTRL,
> +			     IMX95_PEO_LUT_RWA | i);
> +		regmap_read(imx_pcie->iomuxc_gpr, IMX95_PE0_LUT_DATA1, &data1);
> +		regmap_read(imx_pcie->iomuxc_gpr, IMX95_PE0_LUT_DATA2, &data2);
> +		if (data1 & IMX95_PE0_LUT_VLD) {
> +			imx_pcie->luts[i].data1 = data1;
> +			imx_pcie->luts[i].data2 = data2;
> +		} else {
> +			imx_pcie->luts[i].data1 = 0;
> +			imx_pcie->luts[i].data2 = 0;
> +		}
> +	}
> +}
> +
> +static void imx_pcie_lut_restore(struct imx_pcie *imx_pcie)
> +{
> +	int i;
> +
> +	for (i = 0; i < IMX95_MAX_LUT; i++) {
> +		if ((imx_pcie->luts[i].data1 & IMX95_PE0_LUT_VLD) == 0)
> +			continue;
> +
> +		regmap_write(imx_pcie->iomuxc_gpr, IMX95_PE0_LUT_DATA1,
> +			     imx_pcie->luts[i].data1);
> +		regmap_write(imx_pcie->iomuxc_gpr, IMX95_PE0_LUT_DATA2,
> +			     imx_pcie->luts[i].data2);
> +		regmap_write(imx_pcie->iomuxc_gpr, IMX95_PE0_LUT_ACSCTRL, i);
> +	}
> +}
> +
>  static int imx_pcie_suspend_noirq(struct device *dev)
>  {
>  	struct imx_pcie *imx_pcie = dev_get_drvdata(dev);
> @@ -1515,6 +1558,8 @@ static int imx_pcie_suspend_noirq(struct device *dev)
>  		return 0;
>
>  	imx_pcie_msi_save_restore(imx_pcie, true);
> +	if (imx_check_flag(imx_pcie, IMX_PCIE_FLAG_HAS_LUT))
> +		imx_pcie_lut_save(imx_pcie);
>  	if (imx_check_flag(imx_pcie, IMX_PCIE_FLAG_BROKEN_SUSPEND)) {
>  		/*
>  		 * The minimum for a workaround would be to set PERST# and to
> @@ -1559,6 +1604,8 @@ static int imx_pcie_resume_noirq(struct device *dev)
>  		if (ret)
>  			return ret;
>  	}
> +	if (imx_check_flag(imx_pcie, IMX_PCIE_FLAG_HAS_LUT))
> +		imx_pcie_lut_restore(imx_pcie);
>  	imx_pcie_msi_save_restore(imx_pcie, false);
>
>  	return 0;
> --
> 2.37.1
>
diff mbox series

Patch

diff --git a/drivers/pci/controller/dwc/pci-imx6.c b/drivers/pci/controller/dwc/pci-imx6.c
index 1c8834fbcfd5..dc98a04c2956 100644
--- a/drivers/pci/controller/dwc/pci-imx6.c
+++ b/drivers/pci/controller/dwc/pci-imx6.c
@@ -137,6 +137,11 @@  struct imx_pcie_drvdata {
 	const struct dw_pcie_host_ops *ops;
 };
 
+struct imx_lut_data {
+	u32 data1;
+	u32 data2;
+};
+
 struct imx_pcie {
 	struct dw_pcie		*pci;
 	struct gpio_desc	*reset_gpiod;
@@ -156,6 +161,8 @@  struct imx_pcie {
 	struct regulator	*vph;
 	void __iomem		*phy_base;
 
+	/* LUT data for pcie */
+	struct imx_lut_data	luts[IMX95_MAX_LUT];
 	/* power domain for pcie */
 	struct device		*pd_pcie;
 	/* power domain for pcie phy */
@@ -1507,6 +1514,42 @@  static void imx_pcie_msi_save_restore(struct imx_pcie *imx_pcie, bool save)
 	}
 }
 
+static void imx_pcie_lut_save(struct imx_pcie *imx_pcie)
+{
+	u32 data1, data2;
+	int i;
+
+	for (i = 0; i < IMX95_MAX_LUT; i++) {
+		regmap_write(imx_pcie->iomuxc_gpr, IMX95_PE0_LUT_ACSCTRL,
+			     IMX95_PEO_LUT_RWA | i);
+		regmap_read(imx_pcie->iomuxc_gpr, IMX95_PE0_LUT_DATA1, &data1);
+		regmap_read(imx_pcie->iomuxc_gpr, IMX95_PE0_LUT_DATA2, &data2);
+		if (data1 & IMX95_PE0_LUT_VLD) {
+			imx_pcie->luts[i].data1 = data1;
+			imx_pcie->luts[i].data2 = data2;
+		} else {
+			imx_pcie->luts[i].data1 = 0;
+			imx_pcie->luts[i].data2 = 0;
+		}
+	}
+}
+
+static void imx_pcie_lut_restore(struct imx_pcie *imx_pcie)
+{
+	int i;
+
+	for (i = 0; i < IMX95_MAX_LUT; i++) {
+		if ((imx_pcie->luts[i].data1 & IMX95_PE0_LUT_VLD) == 0)
+			continue;
+
+		regmap_write(imx_pcie->iomuxc_gpr, IMX95_PE0_LUT_DATA1,
+			     imx_pcie->luts[i].data1);
+		regmap_write(imx_pcie->iomuxc_gpr, IMX95_PE0_LUT_DATA2,
+			     imx_pcie->luts[i].data2);
+		regmap_write(imx_pcie->iomuxc_gpr, IMX95_PE0_LUT_ACSCTRL, i);
+	}
+}
+
 static int imx_pcie_suspend_noirq(struct device *dev)
 {
 	struct imx_pcie *imx_pcie = dev_get_drvdata(dev);
@@ -1515,6 +1558,8 @@  static int imx_pcie_suspend_noirq(struct device *dev)
 		return 0;
 
 	imx_pcie_msi_save_restore(imx_pcie, true);
+	if (imx_check_flag(imx_pcie, IMX_PCIE_FLAG_HAS_LUT))
+		imx_pcie_lut_save(imx_pcie);
 	if (imx_check_flag(imx_pcie, IMX_PCIE_FLAG_BROKEN_SUSPEND)) {
 		/*
 		 * The minimum for a workaround would be to set PERST# and to
@@ -1559,6 +1604,8 @@  static int imx_pcie_resume_noirq(struct device *dev)
 		if (ret)
 			return ret;
 	}
+	if (imx_check_flag(imx_pcie, IMX_PCIE_FLAG_HAS_LUT))
+		imx_pcie_lut_restore(imx_pcie);
 	imx_pcie_msi_save_restore(imx_pcie, false);
 
 	return 0;