v4.19.13 snapshot.
diff --git a/drivers/pci/controller/pcie-mediatek.c b/drivers/pci/controller/pcie-mediatek.c
new file mode 100644
index 0000000..c5ff6ca
--- /dev/null
+++ b/drivers/pci/controller/pcie-mediatek.c
@@ -0,0 +1,1229 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * MediaTek PCIe host controller driver.
+ *
+ * Copyright (c) 2017 MediaTek Inc.
+ * Author: Ryder Lee <ryder.lee@mediatek.com>
+ *	   Honghui Zhang <honghui.zhang@mediatek.com>
+ */
+
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/iopoll.h>
+#include <linux/irq.h>
+#include <linux/irqchip/chained_irq.h>
+#include <linux/irqdomain.h>
+#include <linux/kernel.h>
+#include <linux/msi.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>
+
+#include "../pci.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_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)
+
+/* PCIe V2 share registers */
+#define PCIE_SYS_CFG_V2		0x0
+#define PCIE_CSR_LTSSM_EN(x)	BIT(0 + (x) * 8)
+#define PCIE_CSR_ASPM_L1_EN(x)	BIT(1 + (x) * 8)
+
+/* PCIe V2 per-port registers */
+#define PCIE_MSI_VECTOR		0x0c0
+
+#define PCIE_CONF_VEND_ID	0x100
+#define PCIE_CONF_CLASS_ID	0x106
+
+#define PCIE_INT_MASK		0x420
+#define INTX_MASK		GENMASK(19, 16)
+#define INTX_SHIFT		16
+#define PCIE_INT_STATUS		0x424
+#define MSI_STATUS		BIT(23)
+#define PCIE_IMSI_STATUS	0x42c
+#define PCIE_IMSI_ADDR		0x430
+#define MSI_MASK		BIT(23)
+#define MTK_MSI_IRQS_NUM	32
+
+#define PCIE_AHB_TRANS_BASE0_L	0x438
+#define PCIE_AHB_TRANS_BASE0_H	0x43c
+#define AHB2PCIE_SIZE(x)	((x) & GENMASK(4, 0))
+#define PCIE_AXI_WINDOW0	0x448
+#define WIN_ENABLE		BIT(7)
+
+/* PCIe V2 configuration transaction header */
+#define PCIE_CFG_HEADER0	0x460
+#define PCIE_CFG_HEADER1	0x464
+#define PCIE_CFG_HEADER2	0x468
+#define PCIE_CFG_WDATA		0x470
+#define PCIE_APP_TLP_REQ	0x488
+#define PCIE_CFG_RDATA		0x48c
+#define APP_CFG_REQ		BIT(0)
+#define APP_CPL_STATUS		GENMASK(7, 5)
+
+#define CFG_WRRD_TYPE_0		4
+#define CFG_WR_FMT		2
+#define CFG_RD_FMT		0
+
+#define CFG_DW0_LENGTH(length)	((length) & GENMASK(9, 0))
+#define CFG_DW0_TYPE(type)	(((type) << 24) & GENMASK(28, 24))
+#define CFG_DW0_FMT(fmt)	(((fmt) << 29) & GENMASK(31, 29))
+#define CFG_DW2_REGN(regn)	((regn) & GENMASK(11, 2))
+#define CFG_DW2_FUN(fun)	(((fun) << 16) & GENMASK(18, 16))
+#define CFG_DW2_DEV(dev)	(((dev) << 19) & GENMASK(23, 19))
+#define CFG_DW2_BUS(bus)	(((bus) << 24) & GENMASK(31, 24))
+#define CFG_HEADER_DW0(type, fmt) \
+	(CFG_DW0_LENGTH(1) | CFG_DW0_TYPE(type) | CFG_DW0_FMT(fmt))
+#define CFG_HEADER_DW1(where, size) \
+	(GENMASK(((size) - 1), 0) << ((where) & 0x3))
+#define CFG_HEADER_DW2(regn, fun, dev, bus) \
+	(CFG_DW2_REGN(regn) | CFG_DW2_FUN(fun) | \
+	CFG_DW2_DEV(dev) | CFG_DW2_BUS(bus))
+
+#define PCIE_RST_CTRL		0x510
+#define PCIE_PHY_RSTB		BIT(0)
+#define PCIE_PIPE_SRSTB		BIT(1)
+#define PCIE_MAC_SRSTB		BIT(2)
+#define PCIE_CRSTB		BIT(3)
+#define PCIE_PERSTB		BIT(8)
+#define PCIE_LINKDOWN_RST_EN	GENMASK(15, 13)
+#define PCIE_LINK_STATUS_V2	0x804
+#define PCIE_PORT_LINKUP_V2	BIT(10)
+
+struct mtk_pcie_port;
+
+/**
+ * struct mtk_pcie_soc - differentiate between host generations
+ * @need_fix_class_id: whether this host's class ID needed to be fixed or not
+ * @ops: pointer to configuration access functions
+ * @startup: pointer to controller setting functions
+ * @setup_irq: pointer to initialize IRQ functions
+ */
+struct mtk_pcie_soc {
+	bool need_fix_class_id;
+	struct pci_ops *ops;
+	int (*startup)(struct mtk_pcie_port *port);
+	int (*setup_irq)(struct mtk_pcie_port *port, struct device_node *node);
+};
+
+/**
+ * struct mtk_pcie_port - PCIe port information
+ * @base: IO mapped register base
+ * @list: port list
+ * @pcie: pointer to PCIe host info
+ * @reset: pointer to port reset control
+ * @sys_ck: pointer to transaction/data link layer clock
+ * @ahb_ck: pointer to AHB slave interface operating clock for CSR access
+ *          and RC initiated MMIO access
+ * @axi_ck: pointer to application layer MMIO channel operating clock
+ * @aux_ck: pointer to pe2_mac_bridge and pe2_mac_core operating clock
+ *          when pcie_mac_ck/pcie_pipe_ck is turned off
+ * @obff_ck: pointer to OBFF functional block operating clock
+ * @pipe_ck: pointer to LTSSM and PHY/MAC layer operating clock
+ * @phy: pointer to PHY control block
+ * @lane: lane count
+ * @slot: port slot
+ * @irq_domain: legacy INTx IRQ domain
+ * @inner_domain: inner IRQ domain
+ * @msi_domain: MSI IRQ domain
+ * @lock: protect the msi_irq_in_use bitmap
+ * @msi_irq_in_use: bit map for assigned MSI IRQ
+ */
+struct mtk_pcie_port {
+	void __iomem *base;
+	struct list_head list;
+	struct mtk_pcie *pcie;
+	struct reset_control *reset;
+	struct clk *sys_ck;
+	struct clk *ahb_ck;
+	struct clk *axi_ck;
+	struct clk *aux_ck;
+	struct clk *obff_ck;
+	struct clk *pipe_ck;
+	struct phy *phy;
+	u32 lane;
+	u32 slot;
+	struct irq_domain *irq_domain;
+	struct irq_domain *inner_domain;
+	struct irq_domain *msi_domain;
+	struct mutex lock;
+	DECLARE_BITMAP(msi_irq_in_use, MTK_MSI_IRQS_NUM);
+};
+
+/**
+ * struct mtk_pcie - PCIe host information
+ * @dev: pointer to PCIe device
+ * @base: IO mapped register base
+ * @free_ck: free-run reference clock
+ * @io: IO resource
+ * @pio: PIO resource
+ * @mem: non-prefetchable memory resource
+ * @busn: bus range
+ * @offset: IO / Memory offset
+ * @ports: pointer to PCIe port information
+ * @soc: pointer to SoC-dependent operations
+ */
+struct mtk_pcie {
+	struct device *dev;
+	void __iomem *base;
+	struct clk *free_ck;
+
+	struct resource io;
+	struct resource pio;
+	struct resource mem;
+	struct resource busn;
+	struct {
+		resource_size_t mem;
+		resource_size_t io;
+	} offset;
+	struct list_head ports;
+	const struct mtk_pcie_soc *soc;
+};
+
+static void mtk_pcie_subsys_powerdown(struct mtk_pcie *pcie)
+{
+	struct device *dev = pcie->dev;
+
+	clk_disable_unprepare(pcie->free_ck);
+
+	if (dev->pm_domain) {
+		pm_runtime_put_sync(dev);
+		pm_runtime_disable(dev);
+	}
+}
+
+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);
+	list_del(&port->list);
+	devm_kfree(dev, port);
+}
+
+static void mtk_pcie_put_resources(struct mtk_pcie *pcie)
+{
+	struct mtk_pcie_port *port, *tmp;
+
+	list_for_each_entry_safe(port, tmp, &pcie->ports, list) {
+		phy_power_off(port->phy);
+		phy_exit(port->phy);
+		clk_disable_unprepare(port->pipe_ck);
+		clk_disable_unprepare(port->obff_ck);
+		clk_disable_unprepare(port->axi_ck);
+		clk_disable_unprepare(port->aux_ck);
+		clk_disable_unprepare(port->ahb_ck);
+		clk_disable_unprepare(port->sys_ck);
+		mtk_pcie_port_free(port);
+	}
+
+	mtk_pcie_subsys_powerdown(pcie);
+}
+
+static int mtk_pcie_check_cfg_cpld(struct mtk_pcie_port *port)
+{
+	u32 val;
+	int err;
+
+	err = readl_poll_timeout_atomic(port->base + PCIE_APP_TLP_REQ, val,
+					!(val & APP_CFG_REQ), 10,
+					100 * USEC_PER_MSEC);
+	if (err)
+		return PCIBIOS_SET_FAILED;
+
+	if (readl(port->base + PCIE_APP_TLP_REQ) & APP_CPL_STATUS)
+		return PCIBIOS_SET_FAILED;
+
+	return PCIBIOS_SUCCESSFUL;
+}
+
+static int mtk_pcie_hw_rd_cfg(struct mtk_pcie_port *port, u32 bus, u32 devfn,
+			      int where, int size, u32 *val)
+{
+	u32 tmp;
+
+	/* Write PCIe configuration transaction header for Cfgrd */
+	writel(CFG_HEADER_DW0(CFG_WRRD_TYPE_0, CFG_RD_FMT),
+	       port->base + PCIE_CFG_HEADER0);
+	writel(CFG_HEADER_DW1(where, size), port->base + PCIE_CFG_HEADER1);
+	writel(CFG_HEADER_DW2(where, PCI_FUNC(devfn), PCI_SLOT(devfn), bus),
+	       port->base + PCIE_CFG_HEADER2);
+
+	/* Trigger h/w to transmit Cfgrd TLP */
+	tmp = readl(port->base + PCIE_APP_TLP_REQ);
+	tmp |= APP_CFG_REQ;
+	writel(tmp, port->base + PCIE_APP_TLP_REQ);
+
+	/* Check completion status */
+	if (mtk_pcie_check_cfg_cpld(port))
+		return PCIBIOS_SET_FAILED;
+
+	/* Read cpld payload of Cfgrd */
+	*val = readl(port->base + PCIE_CFG_RDATA);
+
+	if (size == 1)
+		*val = (*val >> (8 * (where & 3))) & 0xff;
+	else if (size == 2)
+		*val = (*val >> (8 * (where & 3))) & 0xffff;
+
+	return PCIBIOS_SUCCESSFUL;
+}
+
+static int mtk_pcie_hw_wr_cfg(struct mtk_pcie_port *port, u32 bus, u32 devfn,
+			      int where, int size, u32 val)
+{
+	/* Write PCIe configuration transaction header for Cfgwr */
+	writel(CFG_HEADER_DW0(CFG_WRRD_TYPE_0, CFG_WR_FMT),
+	       port->base + PCIE_CFG_HEADER0);
+	writel(CFG_HEADER_DW1(where, size), port->base + PCIE_CFG_HEADER1);
+	writel(CFG_HEADER_DW2(where, PCI_FUNC(devfn), PCI_SLOT(devfn), bus),
+	       port->base + PCIE_CFG_HEADER2);
+
+	/* Write Cfgwr data */
+	val = val << 8 * (where & 3);
+	writel(val, port->base + PCIE_CFG_WDATA);
+
+	/* Trigger h/w to transmit Cfgwr TLP */
+	val = readl(port->base + PCIE_APP_TLP_REQ);
+	val |= APP_CFG_REQ;
+	writel(val, port->base + PCIE_APP_TLP_REQ);
+
+	/* Check completion status */
+	return mtk_pcie_check_cfg_cpld(port);
+}
+
+static struct mtk_pcie_port *mtk_pcie_find_port(struct pci_bus *bus,
+						unsigned int devfn)
+{
+	struct mtk_pcie *pcie = bus->sysdata;
+	struct mtk_pcie_port *port;
+	struct pci_dev *dev = NULL;
+
+	/*
+	 * Walk the bus hierarchy to get the devfn value
+	 * of the port in the root bus.
+	 */
+	while (bus && bus->number) {
+		dev = bus->self;
+		bus = dev->bus;
+		devfn = dev->devfn;
+	}
+
+	list_for_each_entry(port, &pcie->ports, list)
+		if (port->slot == PCI_SLOT(devfn))
+			return port;
+
+	return NULL;
+}
+
+static int mtk_pcie_config_read(struct pci_bus *bus, unsigned int devfn,
+				int where, int size, u32 *val)
+{
+	struct mtk_pcie_port *port;
+	u32 bn = bus->number;
+	int ret;
+
+	port = mtk_pcie_find_port(bus, devfn);
+	if (!port) {
+		*val = ~0;
+		return PCIBIOS_DEVICE_NOT_FOUND;
+	}
+
+	ret = mtk_pcie_hw_rd_cfg(port, bn, devfn, where, size, val);
+	if (ret)
+		*val = ~0;
+
+	return ret;
+}
+
+static int mtk_pcie_config_write(struct pci_bus *bus, unsigned int devfn,
+				 int where, int size, u32 val)
+{
+	struct mtk_pcie_port *port;
+	u32 bn = bus->number;
+
+	port = mtk_pcie_find_port(bus, devfn);
+	if (!port)
+		return PCIBIOS_DEVICE_NOT_FOUND;
+
+	return mtk_pcie_hw_wr_cfg(port, bn, devfn, where, size, val);
+}
+
+static struct pci_ops mtk_pcie_ops_v2 = {
+	.read  = mtk_pcie_config_read,
+	.write = mtk_pcie_config_write,
+};
+
+static int mtk_pcie_startup_port_v2(struct mtk_pcie_port *port)
+{
+	struct mtk_pcie *pcie = port->pcie;
+	struct resource *mem = &pcie->mem;
+	const struct mtk_pcie_soc *soc = port->pcie->soc;
+	u32 val;
+	size_t size;
+	int err;
+
+	/* MT7622 platforms need to enable LTSSM and ASPM from PCIe subsys */
+	if (pcie->base) {
+		val = readl(pcie->base + PCIE_SYS_CFG_V2);
+		val |= PCIE_CSR_LTSSM_EN(port->slot) |
+		       PCIE_CSR_ASPM_L1_EN(port->slot);
+		writel(val, pcie->base + PCIE_SYS_CFG_V2);
+	}
+
+	/* Assert all reset signals */
+	writel(0, port->base + PCIE_RST_CTRL);
+
+	/*
+	 * Enable PCIe link down reset, if link status changed from link up to
+	 * link down, this will reset MAC control registers and configuration
+	 * space.
+	 */
+	writel(PCIE_LINKDOWN_RST_EN, port->base + PCIE_RST_CTRL);
+
+	/* De-assert PHY, PE, PIPE, MAC and configuration reset	*/
+	val = readl(port->base + PCIE_RST_CTRL);
+	val |= PCIE_PHY_RSTB | PCIE_PERSTB | PCIE_PIPE_SRSTB |
+	       PCIE_MAC_SRSTB | PCIE_CRSTB;
+	writel(val, port->base + PCIE_RST_CTRL);
+
+	/* Set up vendor ID and class code */
+	if (soc->need_fix_class_id) {
+		val = PCI_VENDOR_ID_MEDIATEK;
+		writew(val, port->base + PCIE_CONF_VEND_ID);
+
+		val = PCI_CLASS_BRIDGE_HOST;
+		writew(val, port->base + PCIE_CONF_CLASS_ID);
+	}
+
+	/* 100ms timeout value should be enough for Gen1/2 training */
+	err = readl_poll_timeout(port->base + PCIE_LINK_STATUS_V2, val,
+				 !!(val & PCIE_PORT_LINKUP_V2), 20,
+				 100 * USEC_PER_MSEC);
+	if (err)
+		return -ETIMEDOUT;
+
+	/* Set INTx mask */
+	val = readl(port->base + PCIE_INT_MASK);
+	val &= ~INTX_MASK;
+	writel(val, port->base + PCIE_INT_MASK);
+
+	/* Set AHB to PCIe translation windows */
+	size = mem->end - mem->start;
+	val = lower_32_bits(mem->start) | AHB2PCIE_SIZE(fls(size));
+	writel(val, port->base + PCIE_AHB_TRANS_BASE0_L);
+
+	val = upper_32_bits(mem->start);
+	writel(val, port->base + PCIE_AHB_TRANS_BASE0_H);
+
+	/* Set PCIe to AXI translation memory space.*/
+	val = fls(0xffffffff) | WIN_ENABLE;
+	writel(val, port->base + PCIE_AXI_WINDOW0);
+
+	return 0;
+}
+
+static void mtk_compose_msi_msg(struct irq_data *data, struct msi_msg *msg)
+{
+	struct mtk_pcie_port *port = irq_data_get_irq_chip_data(data);
+	phys_addr_t addr;
+
+	/* MT2712/MT7622 only support 32-bit MSI addresses */
+	addr = virt_to_phys(port->base + PCIE_MSI_VECTOR);
+	msg->address_hi = 0;
+	msg->address_lo = lower_32_bits(addr);
+
+	msg->data = data->hwirq;
+
+	dev_dbg(port->pcie->dev, "msi#%d address_hi %#x address_lo %#x\n",
+		(int)data->hwirq, msg->address_hi, msg->address_lo);
+}
+
+static int mtk_msi_set_affinity(struct irq_data *irq_data,
+				const struct cpumask *mask, bool force)
+{
+	 return -EINVAL;
+}
+
+static void mtk_msi_ack_irq(struct irq_data *data)
+{
+	struct mtk_pcie_port *port = irq_data_get_irq_chip_data(data);
+	u32 hwirq = data->hwirq;
+
+	writel(1 << hwirq, port->base + PCIE_IMSI_STATUS);
+}
+
+static struct irq_chip mtk_msi_bottom_irq_chip = {
+	.name			= "MTK MSI",
+	.irq_compose_msi_msg	= mtk_compose_msi_msg,
+	.irq_set_affinity	= mtk_msi_set_affinity,
+	.irq_ack		= mtk_msi_ack_irq,
+};
+
+static int mtk_pcie_irq_domain_alloc(struct irq_domain *domain, unsigned int virq,
+				     unsigned int nr_irqs, void *args)
+{
+	struct mtk_pcie_port *port = domain->host_data;
+	unsigned long bit;
+
+	WARN_ON(nr_irqs != 1);
+	mutex_lock(&port->lock);
+
+	bit = find_first_zero_bit(port->msi_irq_in_use, MTK_MSI_IRQS_NUM);
+	if (bit >= MTK_MSI_IRQS_NUM) {
+		mutex_unlock(&port->lock);
+		return -ENOSPC;
+	}
+
+	__set_bit(bit, port->msi_irq_in_use);
+
+	mutex_unlock(&port->lock);
+
+	irq_domain_set_info(domain, virq, bit, &mtk_msi_bottom_irq_chip,
+			    domain->host_data, handle_edge_irq,
+			    NULL, NULL);
+
+	return 0;
+}
+
+static void mtk_pcie_irq_domain_free(struct irq_domain *domain,
+				     unsigned int virq, unsigned int nr_irqs)
+{
+	struct irq_data *d = irq_domain_get_irq_data(domain, virq);
+	struct mtk_pcie_port *port = irq_data_get_irq_chip_data(d);
+
+	mutex_lock(&port->lock);
+
+	if (!test_bit(d->hwirq, port->msi_irq_in_use))
+		dev_err(port->pcie->dev, "trying to free unused MSI#%lu\n",
+			d->hwirq);
+	else
+		__clear_bit(d->hwirq, port->msi_irq_in_use);
+
+	mutex_unlock(&port->lock);
+
+	irq_domain_free_irqs_parent(domain, virq, nr_irqs);
+}
+
+static const struct irq_domain_ops msi_domain_ops = {
+	.alloc	= mtk_pcie_irq_domain_alloc,
+	.free	= mtk_pcie_irq_domain_free,
+};
+
+static struct irq_chip mtk_msi_irq_chip = {
+	.name		= "MTK PCIe MSI",
+	.irq_ack	= irq_chip_ack_parent,
+	.irq_mask	= pci_msi_mask_irq,
+	.irq_unmask	= pci_msi_unmask_irq,
+};
+
+static struct msi_domain_info mtk_msi_domain_info = {
+	.flags	= (MSI_FLAG_USE_DEF_DOM_OPS | MSI_FLAG_USE_DEF_CHIP_OPS |
+		   MSI_FLAG_PCI_MSIX),
+	.chip	= &mtk_msi_irq_chip,
+};
+
+static int mtk_pcie_allocate_msi_domains(struct mtk_pcie_port *port)
+{
+	struct fwnode_handle *fwnode = of_node_to_fwnode(port->pcie->dev->of_node);
+
+	mutex_init(&port->lock);
+
+	port->inner_domain = irq_domain_create_linear(fwnode, MTK_MSI_IRQS_NUM,
+						      &msi_domain_ops, port);
+	if (!port->inner_domain) {
+		dev_err(port->pcie->dev, "failed to create IRQ domain\n");
+		return -ENOMEM;
+	}
+
+	port->msi_domain = pci_msi_create_irq_domain(fwnode, &mtk_msi_domain_info,
+						     port->inner_domain);
+	if (!port->msi_domain) {
+		dev_err(port->pcie->dev, "failed to create MSI domain\n");
+		irq_domain_remove(port->inner_domain);
+		return -ENOMEM;
+	}
+
+	return 0;
+}
+
+static void mtk_pcie_enable_msi(struct mtk_pcie_port *port)
+{
+	u32 val;
+	phys_addr_t msg_addr;
+
+	msg_addr = virt_to_phys(port->base + PCIE_MSI_VECTOR);
+	val = lower_32_bits(msg_addr);
+	writel(val, port->base + PCIE_IMSI_ADDR);
+
+	val = readl(port->base + PCIE_INT_MASK);
+	val &= ~MSI_MASK;
+	writel(val, port->base + PCIE_INT_MASK);
+}
+
+static int mtk_pcie_intx_map(struct irq_domain *domain, unsigned int irq,
+			     irq_hw_number_t hwirq)
+{
+	irq_set_chip_and_handler(irq, &dummy_irq_chip, handle_simple_irq);
+	irq_set_chip_data(irq, domain->host_data);
+
+	return 0;
+}
+
+static const struct irq_domain_ops intx_domain_ops = {
+	.map = mtk_pcie_intx_map,
+};
+
+static int mtk_pcie_init_irq_domain(struct mtk_pcie_port *port,
+				    struct device_node *node)
+{
+	struct device *dev = port->pcie->dev;
+	struct device_node *pcie_intc_node;
+	int ret;
+
+	/* Setup INTx */
+	pcie_intc_node = of_get_next_child(node, NULL);
+	if (!pcie_intc_node) {
+		dev_err(dev, "no PCIe Intc node found\n");
+		return -ENODEV;
+	}
+
+	port->irq_domain = irq_domain_add_linear(pcie_intc_node, PCI_NUM_INTX,
+						 &intx_domain_ops, port);
+	if (!port->irq_domain) {
+		dev_err(dev, "failed to get INTx IRQ domain\n");
+		return -ENODEV;
+	}
+
+	if (IS_ENABLED(CONFIG_PCI_MSI)) {
+		ret = mtk_pcie_allocate_msi_domains(port);
+		if (ret)
+			return ret;
+
+		mtk_pcie_enable_msi(port);
+	}
+
+	return 0;
+}
+
+static void mtk_pcie_intr_handler(struct irq_desc *desc)
+{
+	struct mtk_pcie_port *port = irq_desc_get_handler_data(desc);
+	struct irq_chip *irqchip = irq_desc_get_chip(desc);
+	unsigned long status;
+	u32 virq;
+	u32 bit = INTX_SHIFT;
+
+	chained_irq_enter(irqchip, desc);
+
+	status = readl(port->base + PCIE_INT_STATUS);
+	if (status & INTX_MASK) {
+		for_each_set_bit_from(bit, &status, PCI_NUM_INTX + INTX_SHIFT) {
+			/* Clear the INTx */
+			writel(1 << bit, port->base + PCIE_INT_STATUS);
+			virq = irq_find_mapping(port->irq_domain,
+						bit - INTX_SHIFT);
+			generic_handle_irq(virq);
+		}
+	}
+
+	if (IS_ENABLED(CONFIG_PCI_MSI)) {
+		if (status & MSI_STATUS){
+			unsigned long imsi_status;
+
+			while ((imsi_status = readl(port->base + PCIE_IMSI_STATUS))) {
+				for_each_set_bit(bit, &imsi_status, MTK_MSI_IRQS_NUM) {
+					virq = irq_find_mapping(port->inner_domain, bit);
+					generic_handle_irq(virq);
+				}
+			}
+			/* Clear MSI interrupt status */
+			writel(MSI_STATUS, port->base + PCIE_INT_STATUS);
+		}
+	}
+
+	chained_irq_exit(irqchip, desc);
+
+	return;
+}
+
+static int mtk_pcie_setup_irq(struct mtk_pcie_port *port,
+			      struct device_node *node)
+{
+	struct mtk_pcie *pcie = port->pcie;
+	struct device *dev = pcie->dev;
+	struct platform_device *pdev = to_platform_device(dev);
+	int err, irq;
+
+	err = mtk_pcie_init_irq_domain(port, node);
+	if (err) {
+		dev_err(dev, "failed to init PCIe IRQ domain\n");
+		return err;
+	}
+
+	irq = platform_get_irq(pdev, port->slot);
+	irq_set_chained_handler_and_data(irq, mtk_pcie_intr_handler, port);
+
+	return 0;
+}
+
+static void __iomem *mtk_pcie_map_bus(struct pci_bus *bus,
+				      unsigned int devfn, int where)
+{
+	struct mtk_pcie *pcie = bus->sysdata;
+
+	writel(PCIE_CONF_ADDR(where, PCI_FUNC(devfn), PCI_SLOT(devfn),
+			      bus->number), pcie->base + PCIE_CFG_ADDR);
+
+	return pcie->base + PCIE_CFG_DATA + (where & 3);
+}
+
+static struct pci_ops mtk_pcie_ops = {
+	.map_bus = mtk_pcie_map_bus,
+	.read  = pci_generic_config_read,
+	.write = pci_generic_config_write,
+};
+
+static int mtk_pcie_startup_port(struct mtk_pcie_port *port)
+{
+	struct mtk_pcie *pcie = port->pcie;
+	u32 func = PCI_FUNC(port->slot << 3);
+	u32 slot = PCI_SLOT(port->slot << 3);
+	u32 val;
+	int err;
+
+	/* assert port PERST_N */
+	val = readl(pcie->base + PCIE_SYS_CFG);
+	val |= PCIE_PORT_PERST(port->slot);
+	writel(val, pcie->base + PCIE_SYS_CFG);
+
+	/* de-assert port PERST_N */
+	val = readl(pcie->base + PCIE_SYS_CFG);
+	val &= ~PCIE_PORT_PERST(port->slot);
+	writel(val, pcie->base + PCIE_SYS_CFG);
+
+	/* 100ms timeout value should be enough for Gen1/2 training */
+	err = readl_poll_timeout(port->base + PCIE_LINK_STATUS, val,
+				 !!(val & PCIE_PORT_LINKUP), 20,
+				 100 * USEC_PER_MSEC);
+	if (err)
+		return -ETIMEDOUT;
+
+	/* enable interrupt */
+	val = readl(pcie->base + PCIE_INT_ENABLE);
+	val |= PCIE_PORT_INT_EN(port->slot);
+	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 */
+	writel(PCIE_CONF_ADDR(PCIE_FC_CREDIT, func, slot, 0),
+	       pcie->base + PCIE_CFG_ADDR);
+	val = readl(pcie->base + PCIE_CFG_DATA);
+	val &= ~PCIE_FC_CREDIT_MASK;
+	val |= PCIE_FC_CREDIT_VAL(0x806c);
+	writel(PCIE_CONF_ADDR(PCIE_FC_CREDIT, func, slot, 0),
+	       pcie->base + PCIE_CFG_ADDR);
+	writel(val, pcie->base + PCIE_CFG_DATA);
+
+	/* configure RC FTS number to 250 when it leaves L0s */
+	writel(PCIE_CONF_ADDR(PCIE_FTS_NUM, func, slot, 0),
+	       pcie->base + PCIE_CFG_ADDR);
+	val = readl(pcie->base + PCIE_CFG_DATA);
+	val &= ~PCIE_FTS_NUM_MASK;
+	val |= PCIE_FTS_NUM_L0(0x50);
+	writel(PCIE_CONF_ADDR(PCIE_FTS_NUM, func, slot, 0),
+	       pcie->base + PCIE_CFG_ADDR);
+	writel(val, pcie->base + PCIE_CFG_DATA);
+
+	return 0;
+}
+
+static void mtk_pcie_enable_port(struct mtk_pcie_port *port)
+{
+	struct mtk_pcie *pcie = port->pcie;
+	struct device *dev = pcie->dev;
+	int err;
+
+	err = clk_prepare_enable(port->sys_ck);
+	if (err) {
+		dev_err(dev, "failed to enable sys_ck%d clock\n", port->slot);
+		goto err_sys_clk;
+	}
+
+	err = clk_prepare_enable(port->ahb_ck);
+	if (err) {
+		dev_err(dev, "failed to enable ahb_ck%d\n", port->slot);
+		goto err_ahb_clk;
+	}
+
+	err = clk_prepare_enable(port->aux_ck);
+	if (err) {
+		dev_err(dev, "failed to enable aux_ck%d\n", port->slot);
+		goto err_aux_clk;
+	}
+
+	err = clk_prepare_enable(port->axi_ck);
+	if (err) {
+		dev_err(dev, "failed to enable axi_ck%d\n", port->slot);
+		goto err_axi_clk;
+	}
+
+	err = clk_prepare_enable(port->obff_ck);
+	if (err) {
+		dev_err(dev, "failed to enable obff_ck%d\n", port->slot);
+		goto err_obff_clk;
+	}
+
+	err = clk_prepare_enable(port->pipe_ck);
+	if (err) {
+		dev_err(dev, "failed to enable pipe_ck%d\n", port->slot);
+		goto err_pipe_clk;
+	}
+
+	reset_control_assert(port->reset);
+	reset_control_deassert(port->reset);
+
+	err = phy_init(port->phy);
+	if (err) {
+		dev_err(dev, "failed to initialize port%d phy\n", port->slot);
+		goto err_phy_init;
+	}
+
+	err = phy_power_on(port->phy);
+	if (err) {
+		dev_err(dev, "failed to power on port%d phy\n", port->slot);
+		goto err_phy_on;
+	}
+
+	if (!pcie->soc->startup(port))
+		return;
+
+	dev_info(dev, "Port%d link down\n", port->slot);
+
+	phy_power_off(port->phy);
+err_phy_on:
+	phy_exit(port->phy);
+err_phy_init:
+	clk_disable_unprepare(port->pipe_ck);
+err_pipe_clk:
+	clk_disable_unprepare(port->obff_ck);
+err_obff_clk:
+	clk_disable_unprepare(port->axi_ck);
+err_axi_clk:
+	clk_disable_unprepare(port->aux_ck);
+err_aux_clk:
+	clk_disable_unprepare(port->ahb_ck);
+err_ahb_clk:
+	clk_disable_unprepare(port->sys_ck);
+err_sys_clk:
+	mtk_pcie_port_free(port);
+}
+
+static int mtk_pcie_parse_port(struct mtk_pcie *pcie,
+			       struct device_node *node,
+			       int slot)
+{
+	struct mtk_pcie_port *port;
+	struct resource *regs;
+	struct device *dev = pcie->dev;
+	struct platform_device *pdev = to_platform_device(dev);
+	char name[10];
+	int err;
+
+	port = devm_kzalloc(dev, sizeof(*port), GFP_KERNEL);
+	if (!port)
+		return -ENOMEM;
+
+	err = of_property_read_u32(node, "num-lanes", &port->lane);
+	if (err) {
+		dev_err(dev, "missing num-lanes property\n");
+		return err;
+	}
+
+	snprintf(name, sizeof(name), "port%d", slot);
+	regs = platform_get_resource_byname(pdev, IORESOURCE_MEM, name);
+	port->base = devm_ioremap_resource(dev, regs);
+	if (IS_ERR(port->base)) {
+		dev_err(dev, "failed to map port%d base\n", slot);
+		return PTR_ERR(port->base);
+	}
+
+	snprintf(name, sizeof(name), "sys_ck%d", slot);
+	port->sys_ck = devm_clk_get(dev, name);
+	if (IS_ERR(port->sys_ck)) {
+		dev_err(dev, "failed to get sys_ck%d clock\n", slot);
+		return PTR_ERR(port->sys_ck);
+	}
+
+	/* sys_ck might be divided into the following parts in some chips */
+	snprintf(name, sizeof(name), "ahb_ck%d", slot);
+	port->ahb_ck = devm_clk_get(dev, name);
+	if (IS_ERR(port->ahb_ck)) {
+		if (PTR_ERR(port->ahb_ck) == -EPROBE_DEFER)
+			return -EPROBE_DEFER;
+
+		port->ahb_ck = NULL;
+	}
+
+	snprintf(name, sizeof(name), "axi_ck%d", slot);
+	port->axi_ck = devm_clk_get(dev, name);
+	if (IS_ERR(port->axi_ck)) {
+		if (PTR_ERR(port->axi_ck) == -EPROBE_DEFER)
+			return -EPROBE_DEFER;
+
+		port->axi_ck = NULL;
+	}
+
+	snprintf(name, sizeof(name), "aux_ck%d", slot);
+	port->aux_ck = devm_clk_get(dev, name);
+	if (IS_ERR(port->aux_ck)) {
+		if (PTR_ERR(port->aux_ck) == -EPROBE_DEFER)
+			return -EPROBE_DEFER;
+
+		port->aux_ck = NULL;
+	}
+
+	snprintf(name, sizeof(name), "obff_ck%d", slot);
+	port->obff_ck = devm_clk_get(dev, name);
+	if (IS_ERR(port->obff_ck)) {
+		if (PTR_ERR(port->obff_ck) == -EPROBE_DEFER)
+			return -EPROBE_DEFER;
+
+		port->obff_ck = NULL;
+	}
+
+	snprintf(name, sizeof(name), "pipe_ck%d", slot);
+	port->pipe_ck = devm_clk_get(dev, name);
+	if (IS_ERR(port->pipe_ck)) {
+		if (PTR_ERR(port->pipe_ck) == -EPROBE_DEFER)
+			return -EPROBE_DEFER;
+
+		port->pipe_ck = NULL;
+	}
+
+	snprintf(name, sizeof(name), "pcie-rst%d", slot);
+	port->reset = devm_reset_control_get_optional_exclusive(dev, name);
+	if (PTR_ERR(port->reset) == -EPROBE_DEFER)
+		return PTR_ERR(port->reset);
+
+	/* some platforms may use default PHY setting */
+	snprintf(name, sizeof(name), "pcie-phy%d", slot);
+	port->phy = devm_phy_optional_get(dev, name);
+	if (IS_ERR(port->phy))
+		return PTR_ERR(port->phy);
+
+	port->slot = slot;
+	port->pcie = pcie;
+
+	if (pcie->soc->setup_irq) {
+		err = pcie->soc->setup_irq(port, node);
+		if (err)
+			return err;
+	}
+
+	INIT_LIST_HEAD(&port->list);
+	list_add_tail(&port->list, &pcie->ports);
+
+	return 0;
+}
+
+static int mtk_pcie_subsys_powerup(struct mtk_pcie *pcie)
+{
+	struct device *dev = pcie->dev;
+	struct platform_device *pdev = to_platform_device(dev);
+	struct resource *regs;
+	int err;
+
+	/* get shared registers, which are optional */
+	regs = platform_get_resource_byname(pdev, IORESOURCE_MEM, "subsys");
+	if (regs) {
+		pcie->base = devm_ioremap_resource(dev, regs);
+		if (IS_ERR(pcie->base)) {
+			dev_err(dev, "failed to map shared register\n");
+			return PTR_ERR(pcie->base);
+		}
+	}
+
+	pcie->free_ck = devm_clk_get(dev, "free_ck");
+	if (IS_ERR(pcie->free_ck)) {
+		if (PTR_ERR(pcie->free_ck) == -EPROBE_DEFER)
+			return -EPROBE_DEFER;
+
+		pcie->free_ck = NULL;
+	}
+
+	if (dev->pm_domain) {
+		pm_runtime_enable(dev);
+		pm_runtime_get_sync(dev);
+	}
+
+	/* enable top level clock */
+	err = clk_prepare_enable(pcie->free_ck);
+	if (err) {
+		dev_err(dev, "failed to enable free_ck\n");
+		goto err_free_ck;
+	}
+
+	return 0;
+
+err_free_ck:
+	if (dev->pm_domain) {
+		pm_runtime_put_sync(dev);
+		pm_runtime_disable(dev);
+	}
+
+	return err;
+}
+
+static int mtk_pcie_setup(struct mtk_pcie *pcie)
+{
+	struct device *dev = pcie->dev;
+	struct device_node *node = dev->of_node, *child;
+	struct of_pci_range_parser parser;
+	struct of_pci_range range;
+	struct resource res;
+	struct mtk_pcie_port *port, *tmp;
+	int err;
+
+	if (of_pci_range_parser_init(&parser, node)) {
+		dev_err(dev, "missing \"ranges\" property\n");
+		return -EINVAL;
+	}
+
+	for_each_of_pci_range(&parser, &range) {
+		err = of_pci_range_to_resource(&range, node, &res);
+		if (err < 0)
+			return err;
+
+		switch (res.flags & IORESOURCE_TYPE_BITS) {
+		case IORESOURCE_IO:
+			pcie->offset.io = res.start - range.pci_addr;
+
+			memcpy(&pcie->pio, &res, sizeof(res));
+			pcie->pio.name = node->full_name;
+
+			pcie->io.start = range.cpu_addr;
+			pcie->io.end = range.cpu_addr + range.size - 1;
+			pcie->io.flags = IORESOURCE_MEM;
+			pcie->io.name = "I/O";
+
+			memcpy(&res, &pcie->io, sizeof(res));
+			break;
+
+		case IORESOURCE_MEM:
+			pcie->offset.mem = res.start - range.pci_addr;
+
+			memcpy(&pcie->mem, &res, sizeof(res));
+			pcie->mem.name = "non-prefetchable";
+			break;
+		}
+	}
+
+	err = of_pci_parse_bus_range(node, &pcie->busn);
+	if (err < 0) {
+		dev_err(dev, "failed to parse bus ranges property: %d\n", err);
+		pcie->busn.name = node->name;
+		pcie->busn.start = 0;
+		pcie->busn.end = 0xff;
+		pcie->busn.flags = IORESOURCE_BUS;
+	}
+
+	for_each_available_child_of_node(node, child) {
+		int slot;
+
+		err = of_pci_get_devfn(child);
+		if (err < 0) {
+			dev_err(dev, "failed to parse devfn: %d\n", err);
+			return err;
+		}
+
+		slot = PCI_SLOT(err);
+
+		err = mtk_pcie_parse_port(pcie, child, slot);
+		if (err)
+			return err;
+	}
+
+	err = mtk_pcie_subsys_powerup(pcie);
+	if (err)
+		return err;
+
+	/* enable each port, and then check link status */
+	list_for_each_entry_safe(port, tmp, &pcie->ports, list)
+		mtk_pcie_enable_port(port);
+
+	/* power down PCIe subsys if slots are all empty (link down) */
+	if (list_empty(&pcie->ports))
+		mtk_pcie_subsys_powerdown(pcie);
+
+	return 0;
+}
+
+static int mtk_pcie_request_resources(struct mtk_pcie *pcie)
+{
+	struct pci_host_bridge *host = pci_host_bridge_from_priv(pcie);
+	struct list_head *windows = &host->windows;
+	struct device *dev = pcie->dev;
+	int err;
+
+	pci_add_resource_offset(windows, &pcie->pio, pcie->offset.io);
+	pci_add_resource_offset(windows, &pcie->mem, pcie->offset.mem);
+	pci_add_resource(windows, &pcie->busn);
+
+	err = devm_request_pci_bus_resources(dev, windows);
+	if (err < 0)
+		return err;
+
+	devm_pci_remap_iospace(dev, &pcie->pio, pcie->io.start);
+
+	return 0;
+}
+
+static int mtk_pcie_register_host(struct pci_host_bridge *host)
+{
+	struct mtk_pcie *pcie = pci_host_bridge_priv(host);
+	struct pci_bus *child;
+	int err;
+
+	host->busnr = pcie->busn.start;
+	host->dev.parent = pcie->dev;
+	host->ops = pcie->soc->ops;
+	host->map_irq = of_irq_parse_and_map_pci;
+	host->swizzle_irq = pci_common_swizzle;
+	host->sysdata = pcie;
+
+	err = pci_scan_root_bus_bridge(host);
+	if (err < 0)
+		return err;
+
+	pci_bus_size_bridges(host->bus);
+	pci_bus_assign_resources(host->bus);
+
+	list_for_each_entry(child, &host->bus->children, node)
+		pcie_bus_configure_settings(child);
+
+	pci_bus_add_devices(host->bus);
+
+	return 0;
+}
+
+static int mtk_pcie_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct mtk_pcie *pcie;
+	struct pci_host_bridge *host;
+	int err;
+
+	host = devm_pci_alloc_host_bridge(dev, sizeof(*pcie));
+	if (!host)
+		return -ENOMEM;
+
+	pcie = pci_host_bridge_priv(host);
+
+	pcie->dev = dev;
+	pcie->soc = of_device_get_match_data(dev);
+	platform_set_drvdata(pdev, pcie);
+	INIT_LIST_HEAD(&pcie->ports);
+
+	err = mtk_pcie_setup(pcie);
+	if (err)
+		return err;
+
+	err = mtk_pcie_request_resources(pcie);
+	if (err)
+		goto put_resources;
+
+	err = mtk_pcie_register_host(host);
+	if (err)
+		goto put_resources;
+
+	return 0;
+
+put_resources:
+	if (!list_empty(&pcie->ports))
+		mtk_pcie_put_resources(pcie);
+
+	return err;
+}
+
+static const struct mtk_pcie_soc mtk_pcie_soc_v1 = {
+	.ops = &mtk_pcie_ops,
+	.startup = mtk_pcie_startup_port,
+};
+
+static const struct mtk_pcie_soc mtk_pcie_soc_mt2712 = {
+	.ops = &mtk_pcie_ops_v2,
+	.startup = mtk_pcie_startup_port_v2,
+	.setup_irq = mtk_pcie_setup_irq,
+};
+
+static const struct mtk_pcie_soc mtk_pcie_soc_mt7622 = {
+	.need_fix_class_id = true,
+	.ops = &mtk_pcie_ops_v2,
+	.startup = mtk_pcie_startup_port_v2,
+	.setup_irq = mtk_pcie_setup_irq,
+};
+
+static const struct of_device_id mtk_pcie_ids[] = {
+	{ .compatible = "mediatek,mt2701-pcie", .data = &mtk_pcie_soc_v1 },
+	{ .compatible = "mediatek,mt7623-pcie", .data = &mtk_pcie_soc_v1 },
+	{ .compatible = "mediatek,mt2712-pcie", .data = &mtk_pcie_soc_mt2712 },
+	{ .compatible = "mediatek,mt7622-pcie", .data = &mtk_pcie_soc_mt7622 },
+	{},
+};
+
+static struct platform_driver mtk_pcie_driver = {
+	.probe = mtk_pcie_probe,
+	.driver = {
+		.name = "mtk-pcie",
+		.of_match_table = mtk_pcie_ids,
+		.suppress_bind_attrs = true,
+	},
+};
+builtin_platform_driver(mtk_pcie_driver);