1 files changed, 57 insertions, 0 deletions

diff --git a/drivers/pci/controller/dwc/pci-imx6.c b/drivers/pci/controller/dwc/pci-imx6.c
index c1d434ba3642..64c74334f7d0 100644
--- a/drivers/pci/controller/dwc/pci-imx6.c
+++ b/drivers/pci/controller/dwc/pci-imx6.c
@@ -19,6 +19,7 @@
 #include <linux/module.h>
 #include <linux/of_gpio.h>
 #include <linux/of_device.h>
+#include <linux/of_address.h>
 #include <linux/pci.h>
 #include <linux/platform_device.h>
 #include <linux/regmap.h>
@@ -77,6 +78,7 @@ struct imx6_pcie {
         u32                     tx_swing_low;
         int                     link_gen;
         struct regulator        *vpcie;
+        void __iomem            *phy_base;
 
         /* power domain for pcie */
         struct device           *pd_pcie;
@@ -134,6 +136,23 @@ struct imx6_pcie {
 #define PCIE_PHY_RX_ASIC_OUT 0x100D
 #define PCIE_PHY_RX_ASIC_OUT_VALID      (1 << 0)
 
+/* iMX7 PCIe PHY registers */
+#define PCIE_PHY_CMN_REG4               0x14
+/* These are probably the bits that *aren't* DCC_FB_EN */
+#define PCIE_PHY_CMN_REG4_DCC_FB_EN     0x29
+
+#define PCIE_PHY_CMN_REG15              0x54
+#define PCIE_PHY_CMN_REG15_DLY_4        BIT(2)
+#define PCIE_PHY_CMN_REG15_PLL_PD       BIT(5)
+#define PCIE_PHY_CMN_REG15_OVRD_PLL_PD  BIT(7)
+
+#define PCIE_PHY_CMN_REG24              0x90
+#define PCIE_PHY_CMN_REG24_RX_EQ        BIT(6)
+#define PCIE_PHY_CMN_REG24_RX_EQ_SEL    BIT(3)
+
+#define PCIE_PHY_CMN_REG26              0x98
+#define PCIE_PHY_CMN_REG26_ATT_MODE     0xBC
+
 #define PHY_RX_OVRD_IN_LO 0x1005
 #define PHY_RX_OVRD_IN_LO_RX_DATA_EN (1 << 5)
 #define PHY_RX_OVRD_IN_LO_RX_PLL_EN (1 << 3)
@@ -533,6 +552,26 @@ static void imx6_pcie_deassert_core_reset(struct imx6_pcie *imx6_pcie)
                 break;
         case IMX7D:
                 reset_control_deassert(imx6_pcie->pciephy_reset);
+
+                /* Workaround for ERR010728, failure of PCI-e PLL VCO to
+                 * oscillate, especially when cold.  This turns off "Duty-cycle
+                 * Corrector" and other mysterious undocumented things.
+                 */
+                if (likely(imx6_pcie->phy_base)) {
+                        /* De-assert DCC_FB_EN */
+                        writel(PCIE_PHY_CMN_REG4_DCC_FB_EN,
+                               imx6_pcie->phy_base + PCIE_PHY_CMN_REG4);
+                        /* Assert RX_EQS and RX_EQS_SEL */
+                        writel(PCIE_PHY_CMN_REG24_RX_EQ_SEL
+                                | PCIE_PHY_CMN_REG24_RX_EQ,
+                               imx6_pcie->phy_base + PCIE_PHY_CMN_REG24);
+                        /* Assert ATT_MODE */
+                        writel(PCIE_PHY_CMN_REG26_ATT_MODE,
+                               imx6_pcie->phy_base + PCIE_PHY_CMN_REG26);
+                } else {
+                        dev_warn(dev, "Unable to apply ERR010728 workaround. DT missing fsl,imx7d-pcie-phy phandle ?\n");
+                }
+
                 imx7d_pcie_wait_for_phy_pll_lock(imx6_pcie);
                 break;
         case IMX6SX:
@@ -994,6 +1033,7 @@ static int imx6_pcie_probe(struct platform_device *pdev)
         struct device *dev = &pdev->dev;
         struct dw_pcie *pci;
         struct imx6_pcie *imx6_pcie;
+        struct device_node *np;
         struct resource *dbi_base;
         struct device_node *node = dev->of_node;
         int ret;
@@ -1013,6 +1053,23 @@ static int imx6_pcie_probe(struct platform_device *pdev)
         imx6_pcie->pci = pci;
         imx6_pcie->drvdata = of_device_get_match_data(dev);
 
+        /* Find the PHY if one is defined, only imx7d uses it */
+        np = of_parse_phandle(node, "fsl,imx7d-pcie-phy", 0);
+        if (np) {
+                struct resource res;
+
+                ret = of_address_to_resource(np, 0, &res);
+                if (ret) {
+                        dev_err(dev, "Unable to map PCIe PHY\n");
+                        return ret;
+                }
+                imx6_pcie->phy_base = devm_ioremap_resource(dev, &res);
+                if (IS_ERR(imx6_pcie->phy_base)) {
+                        dev_err(dev, "Unable to map PCIe PHY\n");
+                        return PTR_ERR(imx6_pcie->phy_base);
+                }
+        }
+
         dbi_base = platform_get_resource(pdev, IORESOURCE_MEM, 0);
         pci->dbi_base = devm_ioremap_resource(dev, dbi_base);
         if (IS_ERR(pci->dbi_base))