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.devSigned-off-by: Sean Anderson <sean.anderson@linux.dev>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

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);
 }