PCI: xilinx-nwl: Add PHY support

Add support for enabling/disabling PCIe PHYs. We can't really do
anything about failures in the disable/remove path, so just print an
error.

Link: https://lore.kernel.org/r/20240531161337.864994-7-sean.anderson@linux.dev
Signed-off-by: Sean Anderson <sean.anderson@linux.dev>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

diff --git a/drivers/pci/controller/pcie-xilinx-nwl.c b/drivers/pci/controller/pcie-xilinx-nwl.c
index e85158dc4e6cb6cf0e1788e1bd80a89f01635f79..d176303579993d3a955066d6fbfae8dba77bfc55 100644 (file)
--- a/drivers/pci/controller/pcie-xilinx-nwl.c
+++ b/drivers/pci/controller/pcie-xilinx-nwl.c
@@ -19,6 +19,7 @@
 #include <linux/of_platform.h>
 #include <linux/pci.h>
 #include <linux/pci-ecam.h>
+#include <linux/phy/phy.h>
 #include <linux/platform_device.h>
 #include <linux/irqchip/chained_irq.h>
 
@@ -157,6 +158,7 @@ struct nwl_pcie {
        void __iomem *breg_base;
        void __iomem *pcireg_base;
        void __iomem *ecam_base;
+       struct phy *phy[4];
        phys_addr_t phys_breg_base;     /* Physical Bridge Register Base */
        phys_addr_t phys_pcie_reg_base; /* Physical PCIe Controller Base */
        phys_addr_t phys_ecam_base;     /* Physical Configuration Base */
@@ -521,6 +523,60 @@ static int nwl_pcie_init_msi_irq_domain(struct nwl_pcie *pcie)
        return 0;
 }
 
+static void nwl_pcie_phy_power_off(struct nwl_pcie *pcie, int i)
+{
+       int err = phy_power_off(pcie->phy[i]);
+
+       if (err)
+               dev_err(pcie->dev, "could not power off phy %d (err=%d)\n", i,
+                       err);
+}
+
+static void nwl_pcie_phy_exit(struct nwl_pcie *pcie, int i)
+{
+       int err = phy_exit(pcie->phy[i]);
+
+       if (err)
+               dev_err(pcie->dev, "could not exit phy %d (err=%d)\n", i, err);
+}
+
+static int nwl_pcie_phy_enable(struct nwl_pcie *pcie)
+{
+       int i, ret;
+
+       for (i = 0; i < ARRAY_SIZE(pcie->phy); i++) {
+               ret = phy_init(pcie->phy[i]);
+               if (ret)
+                       goto err;
+
+               ret = phy_power_on(pcie->phy[i]);
+               if (ret) {
+                       nwl_pcie_phy_exit(pcie, i);
+                       goto err;
+               }
+       }
+
+       return 0;
+
+err:
+       while (i--) {
+               nwl_pcie_phy_power_off(pcie, i);
+               nwl_pcie_phy_exit(pcie, i);
+       }
+
+       return ret;
+}
+
+static void nwl_pcie_phy_disable(struct nwl_pcie *pcie)
+{
+       int i;
+
+       for (i = ARRAY_SIZE(pcie->phy); i--;) {
+               nwl_pcie_phy_power_off(pcie, i);
+               nwl_pcie_phy_exit(pcie, i);
+       }
+}
+
 static int nwl_pcie_init_irq_domain(struct nwl_pcie *pcie)
 {
        struct device *dev = pcie->dev;
@@ -732,6 +788,7 @@ static int nwl_pcie_parse_dt(struct nwl_pcie *pcie,
 {
        struct device *dev = pcie->dev;
        struct resource *res;
+       int i;
 
        res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "breg");
        pcie->breg_base = devm_ioremap_resource(dev, res);
@@ -759,6 +816,18 @@ static int nwl_pcie_parse_dt(struct nwl_pcie *pcie,
        irq_set_chained_handler_and_data(pcie->irq_intx,
                                         nwl_pcie_leg_handler, pcie);
 
+
+       for (i = 0; i < ARRAY_SIZE(pcie->phy); i++) {
+               pcie->phy[i] = devm_of_phy_get_by_index(dev, dev->of_node, i);
+               if (PTR_ERR(pcie->phy[i]) == -ENODEV) {
+                       pcie->phy[i] = NULL;
+                       break;
+               }
+
+               if (IS_ERR(pcie->phy[i]))
+                       return PTR_ERR(pcie->phy[i]);
+       }
+
        return 0;
 }
 
@@ -799,16 +868,22 @@ static int nwl_pcie_probe(struct platform_device *pdev)
                return err;
        }
 
+       err = nwl_pcie_phy_enable(pcie);
+       if (err) {
+               dev_err(dev, "could not enable PHYs\n");
+               goto err_clk;
+       }
+
        err = nwl_pcie_bridge_init(pcie);
        if (err) {
                dev_err(dev, "HW Initialization failed\n");
-               goto err_clk;
+               goto err_phy;
        }
 
        err = nwl_pcie_init_irq_domain(pcie);
        if (err) {
                dev_err(dev, "Failed creating IRQ Domain\n");
-               goto err_clk;
+               goto err_phy;
        }
 
        bridge->sysdata = pcie;
@@ -818,7 +893,7 @@ static int nwl_pcie_probe(struct platform_device *pdev)
                err = nwl_pcie_enable_msi(pcie);
                if (err < 0) {
                        dev_err(dev, "failed to enable MSI support: %d\n", err);
-                       goto err_clk;
+                       goto err_phy;
                }
        }
 
@@ -826,6 +901,8 @@ static int nwl_pcie_probe(struct platform_device *pdev)
        if (!err)
                return 0;
 
+err_phy:
+       nwl_pcie_phy_disable(pcie);
 err_clk:
        clk_disable_unprepare(pcie->clk);
        return err;
@@ -835,6 +912,7 @@ static void nwl_pcie_remove(struct platform_device *pdev)
 {
        struct nwl_pcie *pcie = platform_get_drvdata(pdev);
 
+       nwl_pcie_phy_disable(pcie);
        clk_disable_unprepare(pcie->clk);
 }