PCI: imx: Add the imx8mm pcie support

i.MX8MM PCIe works mostly like the i.MX8MQ one, but has a different PHY
and allows to output the internal PHY reference clock via the refclk pad.
Add the i.MX8MM PCIe support based on the standalone PHY driver.

Link: https://lore.kernel.org/r/1640312885-31142-2-git-send-email-hongxing.zhu@nxp.com
Tested-by: Marcel Ziswiler <marcel.ziswiler@toradex.com>
Tested-by: Tim Harvey <tharvey@gateworks.com>
Signed-off-by: Richard Zhu <hongxing.zhu@nxp.com>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Reviewed-by: Tim Harvey <tharvey@gateworks.com>

diff --git a/drivers/pci/controller/dwc/pci-imx6.c b/drivers/pci/controller/dwc/pci-imx6.c
index 26f49f7..6974bd5 100644 (file)
--- a/drivers/pci/controller/dwc/pci-imx6.c
+++ b/drivers/pci/controller/dwc/pci-imx6.c
@@ -29,6 +29,7 @@
 #include <linux/types.h>
 #include <linux/interrupt.h>
 #include <linux/reset.h>
+#include <linux/phy/phy.h>
 #include <linux/pm_domain.h>
 #include <linux/pm_runtime.h>
 
@@ -49,6 +50,7 @@ enum imx6_pcie_variants {
        IMX6QP,
        IMX7D,
        IMX8MQ,
+       IMX8MM,
 };
 
 #define IMX6_PCIE_FLAG_IMX6_PHY                        BIT(0)
@@ -88,6 +90,7 @@ struct imx6_pcie {
        struct device           *pd_pcie;
        /* power domain for pcie phy */
        struct device           *pd_pcie_phy;
+       struct phy              *phy;
        const struct imx6_pcie_drvdata *drvdata;
 };
 
@@ -372,6 +375,8 @@ static void imx6_pcie_assert_core_reset(struct imx6_pcie *imx6_pcie)
        case IMX7D:
        case IMX8MQ:
                reset_control_assert(imx6_pcie->pciephy_reset);
+               fallthrough;
+       case IMX8MM:
                reset_control_assert(imx6_pcie->apps_reset);
                break;
        case IMX6SX:
@@ -407,7 +412,8 @@ static void imx6_pcie_assert_core_reset(struct imx6_pcie *imx6_pcie)
 
 static unsigned int imx6_pcie_grp_offset(const struct imx6_pcie *imx6_pcie)
 {
-       WARN_ON(imx6_pcie->drvdata->variant != IMX8MQ);
+       WARN_ON(imx6_pcie->drvdata->variant != IMX8MQ &&
+               imx6_pcie->drvdata->variant != IMX8MM);
        return imx6_pcie->controller_id == 1 ? IOMUXC_GPR16 : IOMUXC_GPR14;
 }
 
@@ -446,6 +452,11 @@ static int imx6_pcie_enable_ref_clk(struct imx6_pcie *imx6_pcie)
                break;
        case IMX7D:
                break;
+       case IMX8MM:
+               ret = clk_prepare_enable(imx6_pcie->pcie_aux);
+               if (ret)
+                       dev_err(dev, "unable to enable pcie_aux clock\n");
+               break;
        case IMX8MQ:
                ret = clk_prepare_enable(imx6_pcie->pcie_aux);
                if (ret) {
@@ -522,6 +533,14 @@ static void imx6_pcie_deassert_core_reset(struct imx6_pcie *imx6_pcie)
                goto err_ref_clk;
        }
 
+       switch (imx6_pcie->drvdata->variant) {
+       case IMX8MM:
+               if (phy_power_on(imx6_pcie->phy))
+                       dev_err(dev, "unable to power on PHY\n");
+               break;
+       default:
+               break;
+       }
        /* allow the clocks to stabilize */
        usleep_range(200, 500);
 
@@ -538,6 +557,10 @@ static void imx6_pcie_deassert_core_reset(struct imx6_pcie *imx6_pcie)
        case IMX8MQ:
                reset_control_deassert(imx6_pcie->pciephy_reset);
                break;
+       case IMX8MM:
+               if (phy_init(imx6_pcie->phy))
+                       dev_err(dev, "waiting for phy ready timeout!\n");
+               break;
        case IMX7D:
                reset_control_deassert(imx6_pcie->pciephy_reset);
 
@@ -614,6 +637,12 @@ static void imx6_pcie_configure_type(struct imx6_pcie *imx6_pcie)
 static void imx6_pcie_init_phy(struct imx6_pcie *imx6_pcie)
 {
        switch (imx6_pcie->drvdata->variant) {
+       case IMX8MM:
+               /*
+                * The PHY initialization had been done in the PHY
+                * driver, break here directly.
+                */
+               break;
        case IMX8MQ:
                /*
                 * TODO: Currently this code assumes external
@@ -753,6 +782,7 @@ static void imx6_pcie_ltssm_enable(struct device *dev)
                break;
        case IMX7D:
        case IMX8MQ:
+       case IMX8MM:
                reset_control_deassert(imx6_pcie->apps_reset);
                break;
        }
@@ -871,6 +901,7 @@ static void imx6_pcie_ltssm_disable(struct device *dev)
                                   IMX6Q_GPR12_PCIE_CTL_2, 0);
                break;
        case IMX7D:
+       case IMX8MM:
                reset_control_assert(imx6_pcie->apps_reset);
                break;
        default:
@@ -930,6 +961,7 @@ static void imx6_pcie_clk_disable(struct imx6_pcie *imx6_pcie)
                                   IMX7D_GPR12_PCIE_PHY_REFCLK_SEL);
                break;
        case IMX8MQ:
+       case IMX8MM:
                clk_disable_unprepare(imx6_pcie->pcie_aux);
                break;
        default:
@@ -945,8 +977,16 @@ static int imx6_pcie_suspend_noirq(struct device *dev)
                return 0;
 
        imx6_pcie_pm_turnoff(imx6_pcie);
-       imx6_pcie_clk_disable(imx6_pcie);
        imx6_pcie_ltssm_disable(dev);
+       imx6_pcie_clk_disable(imx6_pcie);
+       switch (imx6_pcie->drvdata->variant) {
+       case IMX8MM:
+               if (phy_power_off(imx6_pcie->phy))
+                       dev_err(dev, "unable to power off PHY\n");
+               break;
+       default:
+               break;
+       }
 
        return 0;
 }
@@ -1043,11 +1083,6 @@ static int imx6_pcie_probe(struct platform_device *pdev)
        }
 
        /* Fetch clocks */
-       imx6_pcie->pcie_phy = devm_clk_get(dev, "pcie_phy");
-       if (IS_ERR(imx6_pcie->pcie_phy))
-               return dev_err_probe(dev, PTR_ERR(imx6_pcie->pcie_phy),
-                                    "pcie_phy clock source missing or invalid\n");
-
        imx6_pcie->pcie_bus = devm_clk_get(dev, "pcie_bus");
        if (IS_ERR(imx6_pcie->pcie_bus))
                return dev_err_probe(dev, PTR_ERR(imx6_pcie->pcie_bus),
@@ -1090,9 +1125,34 @@ static int imx6_pcie_probe(struct platform_device *pdev)
                        return PTR_ERR(imx6_pcie->apps_reset);
                }
                break;
+       case IMX8MM:
+               imx6_pcie->pcie_aux = devm_clk_get(dev, "pcie_aux");
+               if (IS_ERR(imx6_pcie->pcie_aux))
+                       return dev_err_probe(dev, PTR_ERR(imx6_pcie->pcie_aux),
+                                            "pcie_aux clock source missing or invalid\n");
+               imx6_pcie->apps_reset = devm_reset_control_get_exclusive(dev,
+                                                                        "apps");
+               if (IS_ERR(imx6_pcie->apps_reset))
+                       return dev_err_probe(dev, PTR_ERR(imx6_pcie->apps_reset),
+                                            "failed to get pcie apps reset control\n");
+
+               imx6_pcie->phy = devm_phy_get(dev, "pcie-phy");
+               if (IS_ERR(imx6_pcie->phy))
+                       return dev_err_probe(dev, PTR_ERR(imx6_pcie->phy),
+                                            "failed to get pcie phy\n");
+
+               break;
        default:
                break;
        }
+       /* Don't fetch the pcie_phy clock, if it has abstract PHY driver */
+       if (imx6_pcie->phy == NULL) {
+               imx6_pcie->pcie_phy = devm_clk_get(dev, "pcie_phy");
+               if (IS_ERR(imx6_pcie->pcie_phy))
+                       return dev_err_probe(dev, PTR_ERR(imx6_pcie->pcie_phy),
+                                            "pcie_phy clock source missing or invalid\n");
+       }
+
 
        /* Grab turnoff reset */
        imx6_pcie->turnoff_reset = devm_reset_control_get_optional_exclusive(dev, "turnoff");
@@ -1202,6 +1262,10 @@ static const struct imx6_pcie_drvdata drvdata[] = {
        [IMX8MQ] = {
                .variant = IMX8MQ,
        },
+       [IMX8MM] = {
+               .variant = IMX8MM,
+               .flags = IMX6_PCIE_FLAG_SUPPORTS_SUSPEND,
+       },
 };
 
 static const struct of_device_id imx6_pcie_of_match[] = {
@@ -1209,7 +1273,8 @@ static const struct of_device_id imx6_pcie_of_match[] = {
        { .compatible = "fsl,imx6sx-pcie", .data = &drvdata[IMX6SX], },
        { .compatible = "fsl,imx6qp-pcie", .data = &drvdata[IMX6QP], },
        { .compatible = "fsl,imx7d-pcie",  .data = &drvdata[IMX7D],  },
-       { .compatible = "fsl,imx8mq-pcie", .data = &drvdata[IMX8MQ], } ,
+       { .compatible = "fsl,imx8mq-pcie", .data = &drvdata[IMX8MQ], },
+       { .compatible = "fsl,imx8mm-pcie", .data = &drvdata[IMX8MM], },
        {},
 };