6.15-stable review patch. If anyone has any objections, please let me know.
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From: Richard Zhu hongxing.zhu@nxp.com
[ Upstream commit e4d66131caaf18d7c3c69914513f4be0519ddaaf ]
The look up table (LUT) setting would be lost during the PCIe suspend on i.MX95 SoC. So to ensure proper functionality after resume, save it during suspend and restore it while resuming.
Fixes: 9d6b1bd6b3c8 ("PCI: imx6: Add i.MX8MQ, i.MX8Q and i.MX95 PM support") Signed-off-by: Richard Zhu hongxing.zhu@nxp.com [mani: subject and description rewording] Signed-off-by: Manivannan Sadhasivam manivannan.sadhasivam@linaro.org Reviewed-by: Frank Li Frank.Li@nxp.com Reviewed-by: Manivannan Sadhasivam manivannan.sadhasivam@linaro.org Link: https://patch.msgid.link/20250416081314.3929794-8-hongxing.zhu@nxp.com Signed-off-by: Sasha Levin sashal@kernel.org --- 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 5f267dd261b51..ea5c06371171f 100644 --- a/drivers/pci/controller/dwc/pci-imx6.c +++ b/drivers/pci/controller/dwc/pci-imx6.c @@ -129,6 +129,11 @@ 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; @@ -148,6 +153,8 @@ 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 */ @@ -1386,6 +1393,42 @@ 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); @@ -1394,6 +1437,8 @@ 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 @@ -1438,6 +1483,8 @@ 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;