1 files changed, 97 insertions, 5 deletions

diff --git a/drivers/pci/controller/dwc/pci-imx6.c b/drivers/pci/controller/dwc/pci-imx6.c
index 88af6bff945f..52e47dac028f 100644
--- a/drivers/pci/controller/dwc/pci-imx6.c
+++ b/drivers/pci/controller/dwc/pci-imx6.c
@@ -27,6 +27,8 @@
 #include <linux/types.h>
 #include <linux/interrupt.h>
 #include <linux/reset.h>
+#include <linux/pm_domain.h>
+#include <linux/pm_runtime.h>
 
 #include "pcie-designware.h"
 
@@ -59,6 +61,11 @@ struct imx6_pcie {
         u32                     tx_swing_low;
         int                     link_gen;
         struct regulator        *vpcie;
+
+        /* power domain for pcie */
+        struct device           *pd_pcie;
+        /* power domain for pcie phy */
+        struct device           *pd_pcie_phy;
 };
 
 /* Parameters for the waiting for PCIe PHY PLL to lock on i.MX7 */
@@ -67,6 +74,7 @@ struct imx6_pcie {
 #define PHY_PLL_LOCK_WAIT_USLEEP_MAX    200
 
 /* PCIe Root Complex registers (memory-mapped) */
+#define PCIE_RC_IMX6_MSI_CAP                    0x50
 #define PCIE_RC_LCR                             0x7c
 #define PCIE_RC_LCR_MAX_LINK_SPEEDS_GEN1        0x1
 #define PCIE_RC_LCR_MAX_LINK_SPEEDS_GEN2        0x2
@@ -290,6 +298,43 @@ static int imx6q_pcie_abort_handler(unsigned long addr,
         return 1;
 }
 
+static int imx6_pcie_attach_pd(struct device *dev)
+{
+        struct imx6_pcie *imx6_pcie = dev_get_drvdata(dev);
+        struct device_link *link;
+
+        /* Do nothing when in a single power domain */
+        if (dev->pm_domain)
+                return 0;
+
+        imx6_pcie->pd_pcie = dev_pm_domain_attach_by_name(dev, "pcie");
+        if (IS_ERR(imx6_pcie->pd_pcie))
+                return PTR_ERR(imx6_pcie->pd_pcie);
+        link = device_link_add(dev, imx6_pcie->pd_pcie,
+                        DL_FLAG_STATELESS |
+                        DL_FLAG_PM_RUNTIME |
+                        DL_FLAG_RPM_ACTIVE);
+        if (!link) {
+                dev_err(dev, "Failed to add device_link to pcie pd.\n");
+                return -EINVAL;
+        }
+
+        imx6_pcie->pd_pcie_phy = dev_pm_domain_attach_by_name(dev, "pcie_phy");
+        if (IS_ERR(imx6_pcie->pd_pcie_phy))
+                return PTR_ERR(imx6_pcie->pd_pcie_phy);
+
+        device_link_add(dev, imx6_pcie->pd_pcie_phy,
+                        DL_FLAG_STATELESS |
+                        DL_FLAG_PM_RUNTIME |
+                        DL_FLAG_RPM_ACTIVE);
+        if (IS_ERR(link)) {
+                dev_err(dev, "Failed to add device_link to pcie_phy pd: %ld\n", PTR_ERR(link));
+                return PTR_ERR(link);
+        }
+
+        return 0;
+}
+
 static void imx6_pcie_assert_core_reset(struct imx6_pcie *imx6_pcie)
 {
         struct device *dev = imx6_pcie->pci->dev;
@@ -765,8 +810,28 @@ static void imx6_pcie_ltssm_disable(struct device *dev)
 
 static void imx6_pcie_pm_turnoff(struct imx6_pcie *imx6_pcie)
 {
-        reset_control_assert(imx6_pcie->turnoff_reset);
-        reset_control_deassert(imx6_pcie->turnoff_reset);
+        struct device *dev = imx6_pcie->pci->dev;
+
+        /* Some variants have a turnoff reset in DT */
+        if (imx6_pcie->turnoff_reset) {
+                reset_control_assert(imx6_pcie->turnoff_reset);
+                reset_control_deassert(imx6_pcie->turnoff_reset);
+                goto pm_turnoff_sleep;
+        }
+
+        /* Others poke directly at IOMUXC registers */
+        switch (imx6_pcie->variant) {
+        case IMX6SX:
+                regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12,
+                                IMX6SX_GPR12_PCIE_PM_TURN_OFF,
+                                IMX6SX_GPR12_PCIE_PM_TURN_OFF);
+                regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12,
+                                IMX6SX_GPR12_PCIE_PM_TURN_OFF, 0);
+                break;
+        default:
+                dev_err(dev, "PME_Turn_Off not implemented\n");
+                return;
+        }
 
         /*
          * Components with an upstream port must respond to
@@ -775,6 +840,7 @@ static void imx6_pcie_pm_turnoff(struct imx6_pcie *imx6_pcie)
          * The standard recommends a 1-10ms timeout after which to
          * proceed anyway as if acks were received.
          */
+pm_turnoff_sleep:
         usleep_range(1000, 10000);
 }
 
@@ -784,18 +850,31 @@ static void imx6_pcie_clk_disable(struct imx6_pcie *imx6_pcie)
         clk_disable_unprepare(imx6_pcie->pcie_phy);
         clk_disable_unprepare(imx6_pcie->pcie_bus);
 
-        if (imx6_pcie->variant == IMX7D) {
+        switch (imx6_pcie->variant) {
+        case IMX6SX:
+                clk_disable_unprepare(imx6_pcie->pcie_inbound_axi);
+                break;
+        case IMX7D:
                 regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12,
                                    IMX7D_GPR12_PCIE_PHY_REFCLK_SEL,
                                    IMX7D_GPR12_PCIE_PHY_REFCLK_SEL);
+                break;
+        default:
+                break;
         }
 }
 
+static inline bool imx6_pcie_supports_suspend(struct imx6_pcie *imx6_pcie)
+{
+        return (imx6_pcie->variant == IMX7D ||
+                imx6_pcie->variant == IMX6SX);
+}
+
 static int imx6_pcie_suspend_noirq(struct device *dev)
 {
         struct imx6_pcie *imx6_pcie = dev_get_drvdata(dev);
 
-        if (imx6_pcie->variant != IMX7D)
+        if (!imx6_pcie_supports_suspend(imx6_pcie))
                 return 0;
 
         imx6_pcie_pm_turnoff(imx6_pcie);
@@ -811,7 +890,7 @@ static int imx6_pcie_resume_noirq(struct device *dev)
         struct imx6_pcie *imx6_pcie = dev_get_drvdata(dev);
         struct pcie_port *pp = &imx6_pcie->pci->pp;
 
-        if (imx6_pcie->variant != IMX7D)
+        if (!imx6_pcie_supports_suspend(imx6_pcie))
                 return 0;
 
         imx6_pcie_assert_core_reset(imx6_pcie);
@@ -840,6 +919,7 @@ static int imx6_pcie_probe(struct platform_device *pdev)
         struct resource *dbi_base;
         struct device_node *node = dev->of_node;
         int ret;
+        u16 val;
 
         imx6_pcie = devm_kzalloc(dev, sizeof(*imx6_pcie), GFP_KERNEL);
         if (!imx6_pcie)
@@ -977,10 +1057,22 @@ static int imx6_pcie_probe(struct platform_device *pdev)
 
         platform_set_drvdata(pdev, imx6_pcie);
 
+        ret = imx6_pcie_attach_pd(dev);
+        if (ret)
+                return ret;
+
         ret = imx6_add_pcie_port(imx6_pcie, pdev);
         if (ret < 0)
                 return ret;
 
+        if (pci_msi_enabled()) {
+                val = dw_pcie_readw_dbi(pci, PCIE_RC_IMX6_MSI_CAP +
+                                        PCI_MSI_FLAGS);
+                val |= PCI_MSI_FLAGS_ENABLE;
+                dw_pcie_writew_dbi(pci, PCIE_RC_IMX6_MSI_CAP + PCI_MSI_FLAGS,
+                                   val);
+        }
+
         return 0;
 }