PCI: cadence: Refactor driver to use as a core library

Cadence PCIe host and endpoint IP may be embedded into a variety of
SoCs/platforms. Let's extract the platform related APIs/Structures in the
current driver to a separate file (pcie-cadence-plat.c), such that the
common functionality can be used by future platforms.

Signed-off-by: Tom Joseph <tjoseph@cadence.com>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Reviewed-by: Andrew Murray <andrew.murray@arm.com>
diff --git a/drivers/pci/controller/pcie-cadence-plat.c b/drivers/pci/controller/pcie-cadence-plat.c
new file mode 100644
index 0000000..f5c6bf6
--- /dev/null
+++ b/drivers/pci/controller/pcie-cadence-plat.c
@@ -0,0 +1,174 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Cadence PCIe platform  driver.
+ *
+ * Copyright (c) 2019, Cadence Design Systems
+ * Author: Tom Joseph <tjoseph@cadence.com>
+ */
+#include <linux/kernel.h>
+#include <linux/of_address.h>
+#include <linux/of_pci.h>
+#include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
+#include <linux/of_device.h>
+#include "pcie-cadence.h"
+
+/**
+ * struct cdns_plat_pcie - private data for this PCIe platform driver
+ * @pcie: Cadence PCIe controller
+ * @is_rc: Set to 1 indicates the PCIe controller mode is Root Complex,
+ *         if 0 it is in Endpoint mode.
+ */
+struct cdns_plat_pcie {
+	struct cdns_pcie        *pcie;
+	bool is_rc;
+};
+
+struct cdns_plat_pcie_of_data {
+	bool is_rc;
+};
+
+static const struct of_device_id cdns_plat_pcie_of_match[];
+
+static int cdns_plat_pcie_probe(struct platform_device *pdev)
+{
+	const struct cdns_plat_pcie_of_data *data;
+	struct cdns_plat_pcie *cdns_plat_pcie;
+	const struct of_device_id *match;
+	struct device *dev = &pdev->dev;
+	struct pci_host_bridge *bridge;
+	struct cdns_pcie_ep *ep;
+	struct cdns_pcie_rc *rc;
+	int phy_count;
+	bool is_rc;
+	int ret;
+
+	match = of_match_device(cdns_plat_pcie_of_match, dev);
+	if (!match)
+		return -EINVAL;
+
+	data = (struct cdns_plat_pcie_of_data *)match->data;
+	is_rc = data->is_rc;
+
+	pr_debug(" Started %s with is_rc: %d\n", __func__, is_rc);
+	cdns_plat_pcie = devm_kzalloc(dev, sizeof(*cdns_plat_pcie), GFP_KERNEL);
+	if (!cdns_plat_pcie)
+		return -ENOMEM;
+
+	platform_set_drvdata(pdev, cdns_plat_pcie);
+	if (is_rc) {
+		if (!IS_ENABLED(CONFIG_PCIE_CADENCE_PLAT_HOST))
+			return -ENODEV;
+
+		bridge = devm_pci_alloc_host_bridge(dev, sizeof(*rc));
+		if (!bridge)
+			return -ENOMEM;
+
+		rc = pci_host_bridge_priv(bridge);
+		rc->pcie.dev = dev;
+		cdns_plat_pcie->pcie = &rc->pcie;
+		cdns_plat_pcie->is_rc = is_rc;
+
+		ret = cdns_pcie_init_phy(dev, cdns_plat_pcie->pcie);
+		if (ret) {
+			dev_err(dev, "failed to init phy\n");
+			return ret;
+		}
+		pm_runtime_enable(dev);
+		ret = pm_runtime_get_sync(dev);
+		if (ret < 0) {
+			dev_err(dev, "pm_runtime_get_sync() failed\n");
+			goto err_get_sync;
+		}
+
+		ret = cdns_pcie_host_setup(rc);
+		if (ret)
+			goto err_init;
+	} else {
+		if (!IS_ENABLED(CONFIG_PCIE_CADENCE_PLAT_EP))
+			return -ENODEV;
+
+		ep = devm_kzalloc(dev, sizeof(*ep), GFP_KERNEL);
+		if (!ep)
+			return -ENOMEM;
+
+		ep->pcie.dev = dev;
+		cdns_plat_pcie->pcie = &ep->pcie;
+		cdns_plat_pcie->is_rc = is_rc;
+
+		ret = cdns_pcie_init_phy(dev, cdns_plat_pcie->pcie);
+		if (ret) {
+			dev_err(dev, "failed to init phy\n");
+			return ret;
+		}
+
+		pm_runtime_enable(dev);
+		ret = pm_runtime_get_sync(dev);
+		if (ret < 0) {
+			dev_err(dev, "pm_runtime_get_sync() failed\n");
+			goto err_get_sync;
+		}
+
+		ret = cdns_pcie_ep_setup(ep);
+		if (ret)
+			goto err_init;
+	}
+
+ err_init:
+	pm_runtime_put_sync(dev);
+
+ err_get_sync:
+	pm_runtime_disable(dev);
+	cdns_pcie_disable_phy(cdns_plat_pcie->pcie);
+	phy_count = cdns_plat_pcie->pcie->phy_count;
+	while (phy_count--)
+		device_link_del(cdns_plat_pcie->pcie->link[phy_count]);
+
+	return 0;
+}
+
+static void cdns_plat_pcie_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);
+	if (ret < 0)
+		dev_dbg(dev, "pm_runtime_put_sync failed\n");
+
+	pm_runtime_disable(dev);
+
+	cdns_pcie_disable_phy(pcie);
+}
+
+static const struct cdns_plat_pcie_of_data cdns_plat_pcie_host_of_data = {
+	.is_rc = true,
+};
+
+static const struct cdns_plat_pcie_of_data cdns_plat_pcie_ep_of_data = {
+	.is_rc = false,
+};
+
+static const struct of_device_id cdns_plat_pcie_of_match[] = {
+	{
+		.compatible = "cdns,cdns-pcie-host",
+		.data = &cdns_plat_pcie_host_of_data,
+	},
+	{
+		.compatible = "cdns,cdns-pcie-ep",
+		.data = &cdns_plat_pcie_ep_of_data,
+	},
+	{},
+};
+
+static struct platform_driver cdns_plat_pcie_driver = {
+	.driver = {
+		.name = "cdns-pcie",
+		.of_match_table = cdns_plat_pcie_of_match,
+		.pm	= &cdns_pcie_pm_ops,
+	},
+	.probe = cdns_plat_pcie_probe,
+	.shutdown = cdns_plat_pcie_shutdown,
+};
+builtin_platform_driver(cdns_plat_pcie_driver);