On Fri, Mar 28, 2025 at 11:02:13AM +0800, Richard Zhu wrote:
> The look up table(LUT) setting would be lost during PCIe suspend on i.MX95.
>
> To ensure proper functionality after resume, save and restore the LUT
> setting in suspend and resume operations.
>
> Signed-off-by: Richard Zhu <hongxing.zhu@xxxxxxx>
Reviewed-by: Frank Li <Frank.Li@xxxxxxx>
> ---
> 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 40eeb02ffb5d..d8f4608eb7da 100644
> --- a/drivers/pci/controller/dwc/pci-imx6.c
> +++ b/drivers/pci/controller/dwc/pci-imx6.c
> @@ -138,6 +138,11 @@ 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;
> @@ -157,6 +162,8 @@ 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 */
> @@ -1505,6 +1512,42 @@ 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);
> @@ -1513,6 +1556,8 @@ 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
> @@ -1557,6 +1602,8 @@ 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
>
