Merge branch 'pci/controller/dwc-qcom'

- Parse PERST# from all PCIe bridge nodes for future platforms that will
  have PERST# in Switch Downstream Ports as well as in Root Ports
  (Manivannan Sadhasivam)

- Rename qcom PERST# assert/deassert helpers, e.g., qcom_ep_reset_assert(),
  to avoid confusion with Endpoint interfaces (Manivannan Sadhasivam)

* pci/controller/dwc-qcom:
  PCI: qcom: Rename PERST# assert/deassert helpers for uniformity
  PCI: qcom: Parse PERST# from all PCIe bridge nodes

# Conflicts:
#	drivers/pci/controller/dwc/pcie-qcom.c

Author: bjorn-helgaas

drivers/pci/controller/dwc/pcie-qcom.c

@@ -261,10 +261,15 @@ struct qcom_pcie_cfg {
 	bool no_l0s;
 };
 
+struct qcom_pcie_perst {
+	struct list_head list;
+	struct gpio_desc *desc;
+};
+
 struct qcom_pcie_port {
 	struct list_head list;
-	struct gpio_desc *reset;
 	struct phy *phy;
+	struct list_head perst;
 };
 
 struct qcom_pcie {
@@ -283,27 +288,30 @@ struct qcom_pcie {
 
 #define to_qcom_pcie(x)		dev_get_drvdata((x)->dev)
 
-static void qcom_perst_assert(struct qcom_pcie *pcie, bool assert)
+static void __qcom_pcie_perst_assert(struct qcom_pcie *pcie, bool assert)
 {
+	struct qcom_pcie_perst *perst;
 	struct qcom_pcie_port *port;
 	int val = assert ? 1 : 0;
 
-	list_for_each_entry(port, &pcie->ports, list)
-		gpiod_set_value_cansleep(port->reset, val);
+	list_for_each_entry(port, &pcie->ports, list) {
+		list_for_each_entry(perst, &port->perst, list)
+			gpiod_set_value_cansleep(perst->desc, val);
+	}
 
 	usleep_range(PERST_DELAY_US, PERST_DELAY_US + 500);
 }
 
-static void qcom_ep_reset_assert(struct qcom_pcie *pcie)
+static void qcom_pcie_perst_assert(struct qcom_pcie *pcie)
 {
-	qcom_perst_assert(pcie, true);
+	__qcom_pcie_perst_assert(pcie, true);
 }
 
-static void qcom_ep_reset_deassert(struct qcom_pcie *pcie)
+static void qcom_pcie_perst_deassert(struct qcom_pcie *pcie)
 {
-	/* Ensure that PERST has been asserted for at least 100 ms */
+	/* Ensure that PERST# has been asserted for at least 100 ms */
 	msleep(PCIE_T_PVPERL_MS);
-	qcom_perst_assert(pcie, false);
+	__qcom_pcie_perst_assert(pcie, false);
 }
 
 static int qcom_pcie_start_link(struct dw_pcie *pci)
@@ -1282,7 +1290,7 @@ static int qcom_pcie_host_init(struct dw_pcie_rp *pp)
 	struct qcom_pcie *pcie = to_qcom_pcie(pci);
 	int ret;
 
-	qcom_ep_reset_assert(pcie);
+	qcom_pcie_perst_assert(pcie);
 
 	ret = pcie->cfg->ops->init(pcie);
 	if (ret)
@@ -1309,7 +1317,7 @@ static int qcom_pcie_host_init(struct dw_pcie_rp *pp)
 	dw_pcie_remove_capability(pcie->pci, PCI_CAP_ID_MSIX);
 	dw_pcie_remove_ext_capability(pcie->pci, PCI_EXT_CAP_ID_DPC);
 
-	qcom_ep_reset_deassert(pcie);
+	qcom_pcie_perst_deassert(pcie);
 
 	if (pcie->cfg->ops->config_sid) {
 		ret = pcie->cfg->ops->config_sid(pcie);
@@ -1320,7 +1328,7 @@ static int qcom_pcie_host_init(struct dw_pcie_rp *pp)
 	return 0;
 
 err_assert_reset:
-	qcom_ep_reset_assert(pcie);
+	qcom_pcie_perst_assert(pcie);
 err_pwrctrl_power_off:
 	pci_pwrctrl_power_off_devices(pci->dev);
 err_pwrctrl_destroy:
@@ -1339,7 +1347,7 @@ static void qcom_pcie_host_deinit(struct dw_pcie_rp *pp)
 	struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
 	struct qcom_pcie *pcie = to_qcom_pcie(pci);
 
-	qcom_ep_reset_assert(pcie);
+	qcom_pcie_perst_assert(pcie);
 
 	/*
 	 * No need to destroy pwrctrl devices as this function only gets called
@@ -1679,18 +1687,58 @@ static const struct pci_ecam_ops pci_qcom_ecam_ops = {
 	}
 };
 
-static int qcom_pcie_parse_port(struct qcom_pcie *pcie, struct device_node *node)
+/* Parse PERST# from all nodes in depth first manner starting from @np */
+static int qcom_pcie_parse_perst(struct qcom_pcie *pcie,
+				 struct qcom_pcie_port *port,
+				 struct device_node *np)
 {
 	struct device *dev = pcie->pci->dev;
-	struct qcom_pcie_port *port;
+	struct qcom_pcie_perst *perst;
 	struct gpio_desc *reset;
-	struct phy *phy;
 	int ret;
 
-	reset = devm_fwnode_gpiod_get(dev, of_fwnode_handle(node),
-				      "reset", GPIOD_OUT_HIGH, "PERST#");
-	if (IS_ERR(reset))
+	if (!of_find_property(np, "reset-gpios", NULL))
+		goto parse_child_node;
+
+	reset = devm_fwnode_gpiod_get(dev, of_fwnode_handle(np), "reset",
+				      GPIOD_OUT_HIGH, "PERST#");
+	if (IS_ERR(reset)) {
+		/*
+		 * FIXME: GPIOLIB currently supports exclusive GPIO access only.
+		 * Non exclusive access is broken. But shared PERST# requires
+		 * non-exclusive access. So once GPIOLIB properly supports it,
+		 * implement it here.
+		 */
+		if (PTR_ERR(reset) == -EBUSY)
+			dev_err(dev, "Shared PERST# is not supported\n");
+
 		return PTR_ERR(reset);
+	}
+
+	perst = devm_kzalloc(dev, sizeof(*perst), GFP_KERNEL);
+	if (!perst)
+		return -ENOMEM;
+
+	INIT_LIST_HEAD(&perst->list);
+	perst->desc = reset;
+	list_add_tail(&perst->list, &port->perst);
+
+parse_child_node:
+	for_each_available_child_of_node_scoped(np, child) {
+		ret = qcom_pcie_parse_perst(pcie, port, child);
+		if (ret)
+			return ret;
+	}
+
+	return 0;
+}
+
+static int qcom_pcie_parse_port(struct qcom_pcie *pcie, struct device_node *node)
+{
+	struct device *dev = pcie->pci->dev;
+	struct qcom_pcie_port *port;
+	struct phy *phy;
+	int ret;
 
 	phy = devm_of_phy_get(dev, node, NULL);
 	if (IS_ERR(phy))
@@ -1704,7 +1752,12 @@ static int qcom_pcie_parse_port(struct qcom_pcie *pcie, struct device_node *node
 	if (ret)
 		return ret;
 
-	port->reset = reset;
+	INIT_LIST_HEAD(&port->perst);
+
+	ret = qcom_pcie_parse_perst(pcie, port, node);
+	if (ret)
+		return ret;
+
 	port->phy = phy;
 	INIT_LIST_HEAD(&port->list);
 	list_add_tail(&port->list, &pcie->ports);
@@ -1714,9 +1767,10 @@ static int qcom_pcie_parse_port(struct qcom_pcie *pcie, struct device_node *node
 
 static int qcom_pcie_parse_ports(struct qcom_pcie *pcie)
 {
+	struct qcom_pcie_perst *perst, *tmp_perst;
+	struct qcom_pcie_port *port, *tmp_port;
 	struct device *dev = pcie->pci->dev;
-	struct qcom_pcie_port *port, *tmp;
-	int ret = -ENOENT;
+	int ret = -ENODEV;
 
 	for_each_available_child_of_node_scoped(dev->of_node, of_port) {
 		if (!of_node_is_type(of_port, "pci"))
@@ -1729,7 +1783,9 @@ static int qcom_pcie_parse_ports(struct qcom_pcie *pcie)
 	return ret;
 
 err_port_del:
-	list_for_each_entry_safe(port, tmp, &pcie->ports, list) {
+	list_for_each_entry_safe(port, tmp_port, &pcie->ports, list) {
+		list_for_each_entry_safe(perst, tmp_perst, &port->perst, list)
+			list_del(&perst->list);
 		phy_exit(port->phy);
 		list_del(&port->list);
 	}
@@ -1740,6 +1796,7 @@ static int qcom_pcie_parse_ports(struct qcom_pcie *pcie)
 static int qcom_pcie_parse_legacy_binding(struct qcom_pcie *pcie)
 {
 	struct device *dev = pcie->pci->dev;
+	struct qcom_pcie_perst *perst;
 	struct qcom_pcie_port *port;
 	struct gpio_desc *reset;
 	struct phy *phy;
@@ -1761,19 +1818,28 @@ static int qcom_pcie_parse_legacy_binding(struct qcom_pcie *pcie)
 	if (!port)
 		return -ENOMEM;
 
-	port->reset = reset;
+	perst = devm_kzalloc(dev, sizeof(*perst), GFP_KERNEL);
+	if (!perst)
+		return -ENOMEM;
+
 	port->phy = phy;
 	INIT_LIST_HEAD(&port->list);
 	list_add_tail(&port->list, &pcie->ports);
 
+	perst->desc = reset;
+	INIT_LIST_HEAD(&port->perst);
+	INIT_LIST_HEAD(&perst->list);
+	list_add_tail(&perst->list, &port->perst);
+
 	return 0;
 }
 
 static int qcom_pcie_probe(struct platform_device *pdev)
 {
+	struct qcom_pcie_perst *perst, *tmp_perst;
+	struct qcom_pcie_port *port, *tmp_port;
 	const struct qcom_pcie_cfg *pcie_cfg;
 	unsigned long max_freq = ULONG_MAX;
-	struct qcom_pcie_port *port, *tmp;
 	struct device *dev = &pdev->dev;
 	struct dev_pm_opp *opp;
 	struct qcom_pcie *pcie;
@@ -1913,7 +1979,7 @@ static int qcom_pcie_probe(struct platform_device *pdev)
 
 	ret = qcom_pcie_parse_ports(pcie);
 	if (ret) {
-		if (ret != -ENOENT) {
+		if (ret != -ENODEV) {
 			dev_err_probe(pci->dev, ret,
 				      "Failed to parse Root Port: %d\n", ret);
 			goto err_pm_runtime_put;
@@ -1945,7 +2011,9 @@ static int qcom_pcie_probe(struct platform_device *pdev)
 	return 0;
 
 err_phy_exit:
-	list_for_each_entry_safe(port, tmp, &pcie->ports, list) {
+	list_for_each_entry_safe(port, tmp_port, &pcie->ports, list) {
+		list_for_each_entry_safe(perst, tmp_perst, &port->perst, list)
+			list_del(&perst->list);
 		phy_exit(port->phy);
 		list_del(&port->list);
 	}