PCI: cadence: Add generic PHY support to host and EP drivers

If PHYs are present, initialize and enable them at driver probe.
Signed-off-by: Alan Douglas <adouglas@cadence.com>
[lorenzo.pieralisi@arm.com: updated commit log]
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>

drivers/pci/controller/pcie-cadence-ep.c

@@ -439,6 +439,7 @@ static int cdns_pcie_ep_probe(struct platform_device *pdev)
 	struct pci_epc *epc;
 	struct resource *res;
 	int ret;
+	int phy_count;
 
 	ep = devm_kzalloc(dev, sizeof(*ep), GFP_KERNEL);
 	if (!ep)
@@ -473,6 +474,12 @@ static int cdns_pcie_ep_probe(struct platform_device *pdev)
 	if (!ep->ob_addr)
 		return -ENOMEM;
 
+	ret = cdns_pcie_init_phy(dev, pcie);
+	if (ret) {
+		dev_err(dev, "failed to init phy\n");
+		return ret;
+	}
+	platform_set_drvdata(pdev, pcie);
 	pm_runtime_enable(dev);
 	ret = pm_runtime_get_sync(dev);
 	if (ret < 0) {
@@ -521,6 +528,10 @@ static int cdns_pcie_ep_probe(struct platform_device *pdev)
 
  err_get_sync:
 	pm_runtime_disable(dev);
+	cdns_pcie_disable_phy(pcie);
+	phy_count = pcie->phy_count;
+	while (phy_count--)
+		device_link_del(pcie->link[phy_count]);
 
 	return ret;
 }
@@ -528,6 +539,7 @@ static int cdns_pcie_ep_probe(struct platform_device *pdev)
 static void cdns_pcie_ep_shutdown(struct platform_device *pdev)
 {
 	struct device *dev = &pdev->dev;
+	struct cdns_pcie *pcie = dev_get_drvdata(dev);
 	int ret;
 
 	ret = pm_runtime_put_sync(dev);
@@ -536,7 +548,7 @@ static void cdns_pcie_ep_shutdown(struct platform_device *pdev)
 
 	pm_runtime_disable(dev);
 
-	/* The PCIe controller can't be disabled. */
+	cdns_pcie_disable_phy(pcie);
 }
 
 static struct platform_driver cdns_pcie_ep_driver = {

drivers/pci/controller/pcie-cadence-host.c

@@ -58,6 +58,9 @@ static void __iomem *cdns_pci_map_bus(struct pci_bus *bus, unsigned int devfn,
 
 		return pcie->reg_base + (where & 0xfff);
 	}
+	/* Check that the link is up */
+	if (!(cdns_pcie_readl(pcie, CDNS_PCIE_LM_BASE) & 0x1))
+		return NULL;
 
 	/* Update Output registers for AXI region 0. */
 	addr0 = CDNS_PCIE_AT_OB_REGION_PCI_ADDR0_NBITS(12) |
@@ -239,6 +242,7 @@ static int cdns_pcie_host_probe(struct platform_device *pdev)
 	struct cdns_pcie *pcie;
 	struct resource *res;
 	int ret;
+	int phy_count;
 
 	bridge = devm_pci_alloc_host_bridge(dev, sizeof(*rc));
 	if (!bridge)
@@ -290,6 +294,13 @@ static int cdns_pcie_host_probe(struct platform_device *pdev)
 	}
 	pcie->mem_res = res;
 
+	ret = cdns_pcie_init_phy(dev, pcie);
+	if (ret) {
+		dev_err(dev, "failed to init phy\n");
+		return ret;
+	}
+	platform_set_drvdata(pdev, pcie);
+
 	pm_runtime_enable(dev);
 	ret = pm_runtime_get_sync(dev);
 	if (ret < 0) {
@@ -322,6 +333,10 @@ static int cdns_pcie_host_probe(struct platform_device *pdev)
 
  err_get_sync:
 	pm_runtime_disable(dev);
+	cdns_pcie_disable_phy(pcie);
+	phy_count = pcie->phy_count;
+	while (phy_count--)
+		device_link_del(pcie->link[phy_count]);
 
 	return ret;
 }

drivers/pci/controller/pcie-cadence.c

@@ -124,3 +124,96 @@ void cdns_pcie_reset_outbound_region(struct cdns_pcie *pcie, u32 r)
 	cdns_pcie_writel(pcie, CDNS_PCIE_AT_OB_REGION_CPU_ADDR0(r), 0);
 	cdns_pcie_writel(pcie, CDNS_PCIE_AT_OB_REGION_CPU_ADDR1(r), 0);
 }
+
+void cdns_pcie_disable_phy(struct cdns_pcie *pcie)
+{
+	int i = pcie->phy_count;
+
+	while (i--) {
+		phy_power_off(pcie->phy[i]);
+		phy_exit(pcie->phy[i]);
+	}
+}
+
+int cdns_pcie_enable_phy(struct cdns_pcie *pcie)
+{
+	int ret;
+	int i;
+
+	for (i = 0; i < pcie->phy_count; i++) {
+		ret = phy_init(pcie->phy[i]);
+		if (ret < 0)
+			goto err_phy;
+
+		ret = phy_power_on(pcie->phy[i]);
+		if (ret < 0) {
+			phy_exit(pcie->phy[i]);
+			goto err_phy;
+		}
+	}
+
+	return 0;
+
+err_phy:
+	while (--i >= 0) {
+		phy_power_off(pcie->phy[i]);
+		phy_exit(pcie->phy[i]);
+	}
+
+	return ret;
+}
+
+int cdns_pcie_init_phy(struct device *dev, struct cdns_pcie *pcie)
+{
+	struct device_node *np = dev->of_node;
+	int phy_count;
+	struct phy **phy;
+	struct device_link **link;
+	int i;
+	int ret;
+	const char *name;
+
+	phy_count = of_property_count_strings(np, "phy-names");
+	if (phy_count < 1) {
+		dev_err(dev, "no phy-names.  PHY will not be initialized\n");
+		pcie->phy_count = 0;
+		return 0;
+	}
+
+	phy = devm_kzalloc(dev, sizeof(*phy) * phy_count, GFP_KERNEL);
+	if (!phy)
+		return -ENOMEM;
+
+	link = devm_kzalloc(dev, sizeof(*link) * phy_count, GFP_KERNEL);
+	if (!link)
+		return -ENOMEM;
+
+	for (i = 0; i < phy_count; i++) {
+		of_property_read_string_index(np, "phy-names", i, &name);
+		phy[i] = devm_phy_optional_get(dev, name);
+		if (IS_ERR(phy))
+			return PTR_ERR(phy);
+
+		link[i] = device_link_add(dev, &phy[i]->dev, DL_FLAG_STATELESS);
+		if (!link[i]) {
+			ret = -EINVAL;
+			goto err_link;
+		}
+	}
+
+	pcie->phy_count = phy_count;
+	pcie->phy = phy;
+	pcie->link = link;
+
+	ret =  cdns_pcie_enable_phy(pcie);
+	if (ret)
+		goto err_link;
+
+	return 0;
+
+err_link:
+	while (--i >= 0)
+		device_link_del(link[i]);
+
+	return ret;
+}

drivers/pci/controller/pcie-cadence.h

@@ -8,6 +8,7 @@
 
 #include <linux/kernel.h>
 #include <linux/pci.h>
+#include <linux/phy/phy.h>
 
 /*
  * Local Management Registers
@@ -229,6 +230,9 @@ struct cdns_pcie {
 	struct resource		*mem_res;
 	bool			is_rc;
 	u8			bus;
+	int			phy_count;
+	struct phy		**phy;
+	struct device_link	**link;
 };
 
 /* Register access */
@@ -307,5 +311,8 @@ void cdns_pcie_set_outbound_region_for_normal_msg(struct cdns_pcie *pcie, u8 fn,
 						  u32 r, u64 cpu_addr);
 
 void cdns_pcie_reset_outbound_region(struct cdns_pcie *pcie, u32 r);
+void cdns_pcie_disable_phy(struct cdns_pcie *pcie);
+int cdns_pcie_enable_phy(struct cdns_pcie *pcie);
+int cdns_pcie_init_phy(struct device *dev, struct cdns_pcie *pcie);
 
 #endif /* _PCIE_CADENCE_H */