[PATCH 1/2] PCI: mediatek: Add Mediatek PCIe host controller support

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Add support for the Mediatek PCIe controller which can be found
on MT7623A/N, MT2701 and MT8521p platforms.

Signed-off-by: Ryder Lee <ryder.lee@xxxxxxxxxxxx>
---
 drivers/pci/host/Kconfig         |  11 +
 drivers/pci/host/Makefile        |   1 +
 drivers/pci/host/pcie-mediatek.c | 611 +++++++++++++++++++++++++++++++++++++++
 3 files changed, 623 insertions(+)
 create mode 100644 drivers/pci/host/pcie-mediatek.c

diff --git a/drivers/pci/host/Kconfig b/drivers/pci/host/Kconfig
index f7c1d4d..cf13b5d 100644
--- a/drivers/pci/host/Kconfig
+++ b/drivers/pci/host/Kconfig
@@ -174,6 +174,17 @@ config PCIE_ROCKCHIP
 	  There is 1 internal PCIe port available to support GEN2 with
 	  4 slots.
 
+config PCIE_MEDIATEK
+	bool "Mediatek PCIe Controller for MT7623 SoCs families"
+	depends on (ARM && ARCH_MEDIATEK) || COMPILE_TEST
+	depends on OF
+	depends on PCI
+	select PCIEPORTBUS
+	help
+	  Say Y here if you want to enable PCIe controller support on MT7623 A/N
+	  series SoCs. There is a one root complex with 3 root ports available.
+	  Each port supports Gen2 lane x1.
+
 config VMD
 	depends on PCI_MSI && X86_64 && SRCU
 	tristate "Intel Volume Management Device Driver"
diff --git a/drivers/pci/host/Makefile b/drivers/pci/host/Makefile
index 4d36866..265adff 100644
--- a/drivers/pci/host/Makefile
+++ b/drivers/pci/host/Makefile
@@ -17,6 +17,7 @@ obj-$(CONFIG_PCIE_IPROC_BCMA) += pcie-iproc-bcma.o
 obj-$(CONFIG_PCIE_ALTERA) += pcie-altera.o
 obj-$(CONFIG_PCIE_ALTERA_MSI) += pcie-altera-msi.o
 obj-$(CONFIG_PCIE_ROCKCHIP) += pcie-rockchip.o
+obj-$(CONFIG_PCIE_MEDIATEK) += pcie-mediatek.o
 obj-$(CONFIG_VMD) += vmd.o
 
 # The following drivers are for devices that use the generic ACPI
diff --git a/drivers/pci/host/pcie-mediatek.c b/drivers/pci/host/pcie-mediatek.c
new file mode 100644
index 0000000..98e84d9
--- /dev/null
+++ b/drivers/pci/host/pcie-mediatek.c
@@ -0,0 +1,611 @@
+/*
+ * PCIe host controller driver for Mediatek MT7623 SoCs families
+ *
+ * Copyright (c) 2017 MediaTek Inc.
+ * Author: Ryder Lee <ryder.lee@xxxxxxxxxxxx>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of_address.h>
+#include <linux/of_pci.h>
+#include <linux/of_platform.h>
+#include <linux/pci.h>
+#include <linux/phy/phy.h>
+#include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
+#include <linux/reset.h>
+
+/* PCIe shared registers */
+#define PCIE_SYS_CFG		0x00
+#define PCIE_INT_ENABLE		0x0c
+#define PCIE_CFG_ADDR		0x20
+#define PCIE_CFG_DATA		0x24
+
+/* PCIe per port registers */
+#define PCIE_BAR0_SETUP		0x10
+#define PCIE_BAR1_SETUP		0x14
+#define PCIE_BAR0_MEM_BASE	0x18
+#define PCIE_CLASS		0x34
+#define PCIE_LINK_STATUS	0x50
+
+#define PCIE_PORT_INT_EN(x)	BIT(20 + (x))
+#define PCIE_PORT_PERST(x)	BIT(1 + (x))
+#define PCIE_PORT_LINKUP	BIT(0)
+#define PCIE_BAR_MAP_MAX	GENMASK(31, 16)
+
+#define PCIE_BAR_ENABLE		BIT(0)
+#define PCIE_REVISION_ID	BIT(0)
+#define PCIE_CLASS_CODE		(0x60400 << 8)
+#define PCIE_CONF_REG(regn)	(((regn) & GENMASK(7, 2)) | \
+				((((regn) >> 8) & GENMASK(3, 0)) << 24))
+#define PCIE_CONF_FUN(fun)	(((fun) << 8) & GENMASK(10, 8))
+#define PCIE_CONF_DEV(dev)	(((dev) << 11) & GENMASK(15, 11))
+#define PCIE_CONF_BUS(bus)	(((bus) << 16) & GENMASK(23, 16))
+#define PCIE_CONF_ADDR(regn, fun, dev, bus) \
+	(PCIE_CONF_REG(regn) | PCIE_CONF_FUN(fun) | \
+	 PCIE_CONF_DEV(dev) | PCIE_CONF_BUS(bus))
+
+/* Mediatek specific configuration registers */
+#define PCIE_FTS_NUM		0x70c
+#define PCIE_FTS_NUM_MASK	GENMASK(15, 8)
+#define PCIE_FTS_NUM_L0(x)	((x) & 0xff << 8)
+
+#define PCIE_FC_CREDIT		0x73c
+#define PCIE_FC_CREDIT_MASK	(GENMASK(31, 31) | GENMASK(28, 16))
+#define PCIE_FC_CREDIT_VAL(x)	((x) << 16)
+
+/**
+ * struct mtk_pcie_port - PCIe port information
+ * @dev: pointer to root port device
+ * @base: IO mapped register base
+ * @list: port list
+ * @pcie: pointer to PCIe host info
+ * @reset: pointer to RC reset control
+ * @regs: port memory region
+ * @sys_ck: root port clock
+ * @phy: pointer to phy control block
+ * @irq: IRQ number
+ * @lane: lane count
+ * @index: port index
+ */
+struct mtk_pcie_port {
+	struct device *dev;
+	void __iomem *base;
+	struct list_head list;
+	struct mtk_pcie *pcie;
+	struct reset_control *reset;
+	struct resource regs;
+	struct clk *sys_ck;
+	struct phy *phy;
+	int irq;
+	u32 lane;
+	u32 index;
+};
+
+/**
+ * struct mtk_pcie - PCIe host information
+ * @dev: pointer to PCIe device
+ * @base: IO mapped register Base
+ * @free_ck: free-run reference clock
+ * @resources: bus resources
+ * @ports: pointer to PCIe port information
+ */
+struct mtk_pcie {
+	struct device *dev;
+	void __iomem *base;
+	struct clk *free_ck;
+	struct list_head resources;
+	struct list_head ports;
+};
+
+static inline bool mtk_pcie_link_is_up(struct mtk_pcie_port *port)
+{
+	return !!(readl_relaxed(port->base + PCIE_LINK_STATUS) &
+		  PCIE_PORT_LINKUP);
+}
+
+static bool mtk_pcie_valid_device(struct mtk_pcie *pcie,
+				  struct pci_bus *bus, int devfn)
+{
+	struct mtk_pcie_port *port;
+	struct pci_dev *dev;
+	struct pci_bus *pbus;
+
+	/* if there is no link, then there is no device */
+	list_for_each_entry(port, &pcie->ports, list) {
+		if (bus->number == 0 && port->index == PCI_SLOT(devfn) &&
+		    mtk_pcie_link_is_up(port)) {
+			return true;
+		} else if (bus->number != 0) {
+			pbus = bus;
+			do {
+				dev = pbus->self;
+				if (port->index == PCI_SLOT(dev->devfn) &&
+				    mtk_pcie_link_is_up(port)) {
+					return true;
+				}
+				pbus = dev->bus;
+			} while (dev->bus->number != 0);
+		}
+	}
+
+	return false;
+}
+
+static void mtk_pcie_port_free(struct mtk_pcie_port *port)
+{
+	struct mtk_pcie *pcie = port->pcie;
+	struct device *dev = pcie->dev;
+
+	devm_iounmap(dev, port->base);
+	devm_release_mem_region(dev, port->regs.start,
+				resource_size(&port->regs));
+	list_del(&port->list);
+	devm_kfree(dev, port);
+}
+
+static int mtk_pcie_hw_rd_cfg(struct mtk_pcie *pcie, u32 bus, u32 devfn,
+			      int where, int size, u32 *val)
+{
+	writel(PCIE_CONF_ADDR(where, PCI_FUNC(devfn), PCI_SLOT(devfn), bus),
+	       pcie->base + PCIE_CFG_ADDR);
+
+	*val = 0;
+
+	switch (size) {
+	case 1:
+		*val = readb(pcie->base + PCIE_CFG_DATA + (where & 3));
+		break;
+	case 2:
+		*val = readw(pcie->base + PCIE_CFG_DATA + (where & 2));
+		break;
+	case 4:
+		*val = readl(pcie->base + PCIE_CFG_DATA);
+		break;
+	}
+
+	return PCIBIOS_SUCCESSFUL;
+}
+
+static int mtk_pcie_hw_wr_cfg(struct mtk_pcie *pcie, u32 bus, u32 devfn,
+			      int where, int size, u32 val)
+
+{
+	writel(PCIE_CONF_ADDR(where, PCI_FUNC(devfn), PCI_SLOT(devfn), bus),
+	       pcie->base + PCIE_CFG_ADDR);
+
+	switch (size) {
+	case 1:
+		writeb(val, pcie->base + PCIE_CFG_DATA + (where & 3));
+		break;
+	case 2:
+		writew(val, pcie->base + PCIE_CFG_DATA + (where & 2));
+		break;
+	case 4:
+		writel(val, pcie->base + PCIE_CFG_DATA);
+		break;
+	}
+
+	return PCIBIOS_SUCCESSFUL;
+}
+
+static int mtk_pcie_read_config(struct pci_bus *bus, u32 devfn,
+				int where, int size, u32 *val)
+{
+	struct mtk_pcie *pcie = bus->sysdata;
+	u32 bn = bus->number;
+
+	if (!mtk_pcie_valid_device(pcie, bus, devfn)) {
+		*val = 0xffffffff;
+		return PCIBIOS_DEVICE_NOT_FOUND;
+	}
+
+	return mtk_pcie_hw_rd_cfg(pcie, bn, devfn, where, size, val);
+}
+
+static int mtk_pcie_write_config(struct pci_bus *bus, u32 devfn,
+				 int where, int size, u32 val)
+{
+	struct mtk_pcie *pcie = bus->sysdata;
+	u32 bn = bus->number;
+
+	if (!mtk_pcie_valid_device(pcie, bus, devfn))
+		return PCIBIOS_DEVICE_NOT_FOUND;
+
+	return mtk_pcie_hw_wr_cfg(pcie, bn, devfn, where, size, val);
+}
+
+static struct pci_ops mtk_pcie_ops = {
+	.read  = mtk_pcie_read_config,
+	.write = mtk_pcie_write_config,
+};
+
+static void mtk_pcie_configure_rc(struct mtk_pcie_port *port)
+{
+	struct mtk_pcie *pcie = port->pcie;
+	u32 val;
+
+	/* enable interrupt */
+	val = readl(pcie->base + PCIE_INT_ENABLE);
+	val |= PCIE_PORT_INT_EN(port->index);
+	writel(val, pcie->base + PCIE_INT_ENABLE);
+
+	/* map to all DDR region. We need to set it before cfg operation. */
+	writel(PCIE_BAR_MAP_MAX | PCIE_BAR_ENABLE,
+	       port->base + PCIE_BAR0_SETUP);
+
+	/* configure class Code and revision ID */
+	writel(PCIE_CLASS_CODE | PCIE_REVISION_ID,
+	       port->base + PCIE_CLASS);
+
+	/* configure FC credit */
+	mtk_pcie_hw_rd_cfg(pcie, 0, (port->index << 3),
+			   PCIE_FC_CREDIT, 4, &val);
+	val &= ~PCIE_FC_CREDIT_MASK;
+	val |= PCIE_FC_CREDIT_VAL(0x806c);
+	mtk_pcie_hw_wr_cfg(pcie, 0, (port->index << 3),
+			   PCIE_FC_CREDIT, 4, val);
+
+	/* configure RC FTS number to 250 when it leaves L0s */
+	mtk_pcie_hw_rd_cfg(pcie, 0, (port->index << 3),
+			   PCIE_FTS_NUM, 4, &val);
+	val &= ~PCIE_FTS_NUM_MASK;
+	val |= PCIE_FTS_NUM_L0(0x50);
+	mtk_pcie_hw_wr_cfg(pcie, 0, (port->index << 3),
+			   PCIE_FTS_NUM, 4, val);
+}
+
+static void mtk_pcie_assert_ports(struct mtk_pcie_port *port)
+{
+	struct mtk_pcie *pcie = port->pcie;
+	u32 val;
+
+	/* assert port PERST_N */
+	val = readl(pcie->base + PCIE_SYS_CFG);
+	val |= PCIE_PORT_PERST(port->index);
+	writel(val, pcie->base + PCIE_SYS_CFG);
+
+	/* de-assert port PERST_N */
+	val = readl(pcie->base + PCIE_SYS_CFG);
+	val &= ~PCIE_PORT_PERST(port->index);
+	writel(val, pcie->base + PCIE_SYS_CFG);
+
+	/*
+	 * at least 100ms delay because PCIe v2.0 need more time to
+	 * train from Gen1 to Gen2
+	 */
+	msleep(100);
+}
+
+static int mtk_pcie_enable_ports(struct mtk_pcie *pcie)
+{
+	struct device *dev = pcie->dev;
+	struct mtk_pcie_port *port, *tmp;
+	int err, linkup = 0;
+
+	list_for_each_entry_safe(port, tmp, &pcie->ports, list) {
+		err = clk_prepare_enable(port->sys_ck);
+		if (err) {
+			dev_err(dev, "failed to enable port%d clock\n",
+				port->index);
+			continue;
+		}
+
+		/* assert RC */
+		reset_control_assert(port->reset);
+		/* de-assert RC */
+		reset_control_deassert(port->reset);
+
+		/* power on PHY */
+		err = phy_power_on(port->phy);
+		if (err) {
+			dev_err(dev, "failed to power on port%d phy\n",
+				port->index);
+			goto err_phy_on;
+		}
+
+		mtk_pcie_assert_ports(port);
+
+		/* if link up, then setup root port configuration space */
+		if (mtk_pcie_link_is_up(port)) {
+			mtk_pcie_configure_rc(port);
+			linkup++;
+			continue;
+		}
+
+		dev_info(dev, "Port%d link down\n", port->index);
+
+		phy_power_off(port->phy);
+err_phy_on:
+		clk_disable_unprepare(port->sys_ck);
+		mtk_pcie_port_free(port);
+	}
+
+	return linkup;
+}
+
+static int mtk_pcie_get_port_resource(struct mtk_pcie_port *port,
+				      struct device_node *node)
+{
+	struct device *dev = port->pcie->dev;
+	struct platform_device *pdev = to_platform_device(dev);
+	struct platform_device *plat_dev;
+	char name[10];
+	int err;
+
+	err = of_address_to_resource(node, 0, &port->regs);
+	if (err) {
+		dev_err(dev, "failed to parse address: %d\n", err);
+		return err;
+	}
+
+	port->base = devm_ioremap_resource(dev, &port->regs);
+	if (IS_ERR(port->base)) {
+		dev_err(dev, "failed to map port%d base\n", port->index);
+		return PTR_ERR(port->base);
+	}
+
+	plat_dev = of_find_device_by_node(node);
+	if (!plat_dev) {
+		plat_dev = of_platform_device_create(
+					node, NULL,
+					platform_bus_type.dev_root);
+		if (!plat_dev)
+			return -EPROBE_DEFER;
+	}
+
+	port->dev = &plat_dev->dev;
+
+	port->irq = platform_get_irq(pdev, port->index);
+	if (!port->irq) {
+		dev_err(dev, "failed to get irq\n");
+		return -ENODEV;
+	}
+
+	port->sys_ck = devm_clk_get(port->dev, "sys_ck");
+	if (IS_ERR(port->sys_ck)) {
+		dev_err(port->dev, "failed to get port%d clock\n", port->index);
+		return PTR_ERR(port->sys_ck);
+	}
+
+	port->reset = devm_reset_control_get(port->dev, "pcie-reset");
+	if (IS_ERR(port->reset)) {
+		dev_err(port->dev, "failed to get port%d reset control\n",
+			port->index);
+		return PTR_ERR(port->reset);
+	}
+
+	snprintf(name, sizeof(name), "pcie-phy%d", port->index);
+	port->phy = devm_of_phy_get(port->dev, node, name);
+	if (IS_ERR(port->phy)) {
+		dev_err(port->dev, "failed to get port%d phy\n", port->index);
+		return PTR_ERR(port->phy);
+	}
+
+	return 0;
+}
+
+static int mtk_pcie_parse_and_add_res(struct mtk_pcie *pcie)
+{
+	struct device *dev = pcie->dev;
+	struct platform_device *pdev = to_platform_device(dev);
+	struct device_node *node = dev->of_node, *child;
+	struct resource_entry *win, *tmp;
+	struct resource *regs;
+	resource_size_t iobase;
+	int err;
+
+	/* parse shared resources */
+	regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	pcie->base = devm_ioremap_resource(dev, regs);
+	if (IS_ERR(pcie->base)) {
+		dev_err(dev, "failed to get PCIe base\n");
+		return PTR_ERR(pcie->base);
+	}
+
+	pcie->free_ck = devm_clk_get(dev, "free_ck");
+	if (IS_ERR(pcie->free_ck)) {
+		dev_err(dev, "failed to get free_ck\n");
+		return PTR_ERR(pcie->free_ck);
+	}
+
+	err = of_pci_get_host_bridge_resources(node, 0, 0xff, &pcie->resources,
+					       &iobase);
+	if (err)
+		return err;
+
+	err = devm_request_pci_bus_resources(dev, &pcie->resources);
+	if (err)
+		return err;
+
+	resource_list_for_each_entry_safe(win, tmp, &pcie->resources) {
+		struct resource *res = win->res;
+
+		switch (resource_type(res)) {
+		case IORESOURCE_IO:
+			err = pci_remap_iospace(res, iobase);
+			if (err) {
+				dev_warn(dev, "failed to map resource %pR\n",
+					 res);
+				resource_list_destroy_entry(win);
+			}
+			break;
+		}
+	}
+
+	/* parse port resources */
+	for_each_child_of_node(node, child) {
+		struct mtk_pcie_port *port;
+		int index;
+
+		err = of_pci_get_devfn(child);
+		if (err < 0) {
+			dev_err(pcie->dev, "failed to parse devfn: %d\n", err);
+			return err;
+		}
+
+		index = PCI_SLOT(err);
+		if (index < 1) {
+			dev_err(dev, "invalid port number: %d\n", index);
+			return -EINVAL;
+		}
+
+		index--;
+
+		if (!of_device_is_available(child))
+			continue;
+
+		port = devm_kzalloc(dev, sizeof(*port), GFP_KERNEL);
+		if (!port)
+			return -ENOMEM;
+
+		err = of_property_read_u32(child, "num-lanes", &port->lane);
+		if (err) {
+			dev_err(dev, "missing num-lanes property\n");
+			return err;
+		}
+
+		port->index = index;
+		port->pcie = pcie;
+
+		err = mtk_pcie_get_port_resource(port, child);
+		if (err)
+			return err;
+
+		INIT_LIST_HEAD(&port->list);
+		list_add_tail(&port->list, &pcie->ports);
+	}
+
+	return 0;
+}
+
+/*
+ * This IP lacks interrupt status register to check or map INTx from
+ * different devices at the same time.
+ */
+static int __init mtk_pcie_map_irq(const struct pci_dev *dev, u8 slot, u8 pin)
+{
+	struct mtk_pcie *pcie = dev->bus->sysdata;
+	struct mtk_pcie_port *port;
+
+	list_for_each_entry(port, &pcie->ports, list)
+		if (port->index == slot)
+			return port->irq;
+
+	return -1;
+}
+
+static int mtk_pcie_register_ports(struct mtk_pcie *pcie)
+{
+	struct pci_bus *bus, *child;
+
+	bus = pci_scan_root_bus(pcie->dev, 0, &mtk_pcie_ops, pcie,
+				&pcie->resources);
+	if (!bus) {
+		dev_err(pcie->dev, "failed to create root bus\n");
+		return -ENOMEM;
+	}
+
+	if (!pci_has_flag(PCI_PROBE_ONLY)) {
+		pci_fixup_irqs(pci_common_swizzle, mtk_pcie_map_irq);
+		pci_bus_size_bridges(bus);
+		pci_bus_assign_resources(bus);
+
+		list_for_each_entry(child, &bus->children, node)
+			pcie_bus_configure_settings(child);
+	}
+
+	pci_bus_add_devices(bus);
+
+	return 0;
+}
+
+static int mtk_pcie_probe(struct platform_device *pdev)
+{
+	struct mtk_pcie *pcie;
+	int err;
+
+	pcie = devm_kzalloc(&pdev->dev, sizeof(*pcie), GFP_KERNEL);
+	if (!pcie)
+		return -ENOMEM;
+
+	pcie->dev = &pdev->dev;
+	platform_set_drvdata(pdev, pcie);
+
+	/*
+	 * parse PCI ranges, configuration bus range and
+	 * request their resources
+	 */
+	INIT_LIST_HEAD(&pcie->ports);
+	INIT_LIST_HEAD(&pcie->resources);
+
+	err = mtk_pcie_parse_and_add_res(pcie);
+	if (err)
+		goto err_parse;
+
+	pm_runtime_enable(pcie->dev);
+	err = pm_runtime_get_sync(pcie->dev);
+	if (err)
+		goto err_pm;
+
+	err = clk_prepare_enable(pcie->free_ck);
+	if (err) {
+		dev_err(pcie->dev, "failed to enable free_ck\n");
+		goto err_free_ck;
+	}
+
+	/* power on PCIe ports */
+	err = mtk_pcie_enable_ports(pcie);
+	if (!err)
+		goto err_enable;
+
+	/* register PCIe ports */
+	err = mtk_pcie_register_ports(pcie);
+	if (err)
+		goto err_enable;
+
+	return 0;
+
+err_enable:
+	clk_disable_unprepare(pcie->free_ck);
+err_free_ck:
+	pm_runtime_put_sync(pcie->dev);
+err_pm:
+	pm_runtime_disable(pcie->dev);
+err_parse:
+	pci_free_resource_list(&pcie->resources);
+
+	return err;
+}
+
+static const struct of_device_id mtk_pcie_ids[] = {
+	{ .compatible = "mediatek,mt7623-pcie"},
+	{ .compatible = "mediatek,mt2701-pcie"},
+	{},
+};
+MODULE_DEVICE_TABLE(of, mtk_pcie_ids);
+
+static struct platform_driver mtk_pcie_driver = {
+	.probe = mtk_pcie_probe,
+	.driver = {
+		.name = "mtk-pcie",
+		.of_match_table = mtk_pcie_ids,
+	},
+};
+
+builtin_platform_driver(mtk_pcie_driver);
+
+MODULE_DESCRIPTION("Mediatek PCIe host driver for MT7623 SoCs families");
+MODULE_LICENSE("GPL v2");
-- 
1.9.1




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