[v3,2/3] PCI: mediatek: Add new generation controller support

[Jianjun Wang]

MediaTek's PCIe host controller has three generation HWs, the new
generation HW is an individual bridge, it supoorts Gen3 speed and
up to 256 MSI interrupt numbers for multi-function devices.

Add support for new Gen3 controller which can be found on MT8192.

Signed-off-by: Jianjun Wang <jianjun.wang@xxxxxxxxxxxx>
Acked-by: Ryder Lee <ryder.lee@xxxxxxxxxxxx>
---
 drivers/pci/controller/Kconfig              |   14 +
 drivers/pci/controller/Makefile             |    1 +
 drivers/pci/controller/pcie-mediatek-gen3.c | 1024 +++++++++++++++++++
 3 files changed, 1039 insertions(+)
 create mode 100644 drivers/pci/controller/pcie-mediatek-gen3.c

diff --git a/drivers/pci/controller/Kconfig b/drivers/pci/controller/Kconfig
index f18c3725ef80..83daa772595b 100644
--- a/drivers/pci/controller/Kconfig
+++ b/drivers/pci/controller/Kconfig
@@ -239,6 +239,20 @@ config PCIE_MEDIATEK
 	  Say Y here if you want to enable PCIe controller support on
 	  MediaTek SoCs.
 
+config PCIE_MEDIATEK_GEN3
+	tristate "MediaTek GEN3 PCIe controller"
+	depends on ARCH_MEDIATEK || COMPILE_TEST
+	depends on OF
+	depends on PCI_MSI_IRQ_DOMAIN
+	help
+	  Adds support for PCIe Gen3 MAC controller for MediaTek SoCs.
+	  This PCIe controller provides the capable of Gen3, Gen2 and
+	  Gen1 speed, and support up to 256 MSI interrupt numbers for
+	  multi-function devices.
+
+	  Say Y here if you want to enable Gen3 PCIe controller support on
+	  MediaTek SoCs.
+
 config PCIE_TANGO_SMP8759
 	bool "Tango SMP8759 PCIe controller (DANGEROUS)"
 	depends on ARCH_TANGO && PCI_MSI && OF
diff --git a/drivers/pci/controller/Makefile b/drivers/pci/controller/Makefile
index bcdbf49ab1e4..9c1b96777597 100644
--- a/drivers/pci/controller/Makefile
+++ b/drivers/pci/controller/Makefile
@@ -27,6 +27,7 @@ obj-$(CONFIG_PCIE_ROCKCHIP) += pcie-rockchip.o
 obj-$(CONFIG_PCIE_ROCKCHIP_EP) += pcie-rockchip-ep.o
 obj-$(CONFIG_PCIE_ROCKCHIP_HOST) += pcie-rockchip-host.o
 obj-$(CONFIG_PCIE_MEDIATEK) += pcie-mediatek.o
+obj-$(CONFIG_PCIE_MEDIATEK_GEN3) += pcie-mediatek-gen3.o
 obj-$(CONFIG_PCIE_TANGO_SMP8759) += pcie-tango.o
 obj-$(CONFIG_VMD) += vmd.o
 obj-$(CONFIG_PCIE_BRCMSTB) += pcie-brcmstb.o
diff --git a/drivers/pci/controller/pcie-mediatek-gen3.c b/drivers/pci/controller/pcie-mediatek-gen3.c
new file mode 100644
index 000000000000..ad69c789b24d
--- /dev/null
+++ b/drivers/pci/controller/pcie-mediatek-gen3.c
@@ -0,0 +1,1024 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * MediaTek PCIe host controller driver.
+ *
+ * Copyright (c) 2020 MediaTek Inc.
+ * Author: Jianjun Wang <jianjun.wang@xxxxxxxxxxxx>
+ */
+
+#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/module.h>
+#include <linux/msi.h>
+#include <linux/of_address.h>
+#include <linux/of_clk.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_domain.h>
+#include <linux/pm_runtime.h>
+#include <linux/reset.h>
+
+#include "../pci.h"
+
+#define PCIE_SETTING_REG		0x80
+#define PCIE_PCI_IDS_1			0x9c
+#define PCI_CLASS(class)		(class << 8)
+#define PCIE_RC_MODE			BIT(0)
+
+#define PCIE_CFGNUM_REG			0x140
+#define PCIE_CFG_DEVFN(devfn)		((devfn) & GENMASK(7, 0))
+#define PCIE_CFG_BUS(bus)		(((bus) << 8) & GENMASK(15, 8))
+#define PCIE_CFG_BYTE_EN(bytes)		(((bytes) << 16) & GENMASK(19, 16))
+#define PCIE_CFG_FORCE_BYTE_EN		BIT(20)
+#define PCIE_CFG_OFFSET_ADDR		0x1000
+#define PCIE_CFG_HEADER(devfn, bus) \
+	(PCIE_CFG_DEVFN(devfn) | PCIE_CFG_BUS(bus))
+
+#define PCIE_CFG_HEADER_FORCE_BE(devfn, bus, bytes) \
+	(PCIE_CFG_HEADER(devfn, bus) | PCIE_CFG_BYTE_EN(bytes) \
+	 | PCIE_CFG_FORCE_BYTE_EN)
+
+#define PCIE_RST_CTRL_REG		0x148
+#define PCIE_MAC_RSTB			BIT(0)
+#define PCIE_PHY_RSTB			BIT(1)
+#define PCIE_BRG_RSTB			BIT(2)
+#define PCIE_PE_RSTB			BIT(3)
+
+#define PCIE_MISC_STATUS_REG		0x14C
+#define PCIE_LTR_MSG_RECEIVED		BIT(0)
+#define PCIE_PCIE_MSG_RECEIVED		BIT(1)
+
+#define PCIE_LTSSM_STATUS_REG		0x150
+#define PCIE_LTSSM_STATE_MASK		GENMASK(28, 24)
+#define PCIE_LTSSM_STATE(val)		((val & PCIE_LTSSM_STATE_MASK) >> 24)
+#define PCIE_LTSSM_STATE_L0		0x10
+#define PCIE_LTSSM_STATE_L1_IDLE	0x13
+#define PCIE_LTSSM_STATE_L2_IDLE	0x14
+
+#define PCIE_LINK_STATUS_REG		0x154
+#define PCIE_PORT_LINKUP		BIT(8)
+
+#define PCIE_MSI_SET_NUM		8
+#define PCIE_MSI_IRQS_PER_SET		32
+#define PCIE_MSI_IRQS_NUM \
+	(PCIE_MSI_IRQS_PER_SET * (PCIE_MSI_SET_NUM))
+
+#define PCIE_INT_ENABLE_REG		0x180
+#define PCIE_MSI_MASK			GENMASK(PCIE_MSI_SET_NUM + 8 - 1, 8)
+#define PCIE_MSI_SHIFT			8
+#define PCIE_INTX_SHIFT			24
+#define PCIE_INTX_MASK			GENMASK(27, 24)
+#define PCIE_MSG_MASK			BIT(28)
+#define PCIE_AER_MASK			BIT(29)
+#define PCIE_PM_MASK			BIT(30)
+
+#define PCIE_INT_STATUS_REG		0x184
+#define PCIE_MSI_SET_ENABLE_REG		0x190
+
+#define PCIE_LOW_POWER_CTRL_REG		0x194
+#define PCIE_DIS_LOWPWR_MASK		GENMASK(3, 0)
+#define PCIE_DIS_L0S_MASK		BIT(0)
+#define PCIE_DIS_L1_MASK		BIT(1)
+#define PCIE_DIS_L11_MASK		BIT(2)
+#define PCIE_DIS_L12_MASK		BIT(3)
+#define PCIE_FORCE_DIS_LOWPWR		GENMASK(11, 8)
+#define PCIE_FORCE_DIS_L0S		BIT(8)
+#define PCIE_FORCE_DIS_L1		BIT(9)
+#define PCIE_FORCE_DIS_L11		BIT(10)
+#define PCIE_FORCE_DIS_L12		BIT(11)
+
+#define PCIE_ICMD_PM_REG		0x198
+#define PCIE_TURN_OFF_LINK		BIT(4)
+
+#define PCIE_MSI_ADDR_BASE_REG		0xc00
+#define PCIE_MSI_SET_OFFSET		0x10
+#define PCIE_MSI_STATUS_OFFSET		0x04
+#define PCIE_MSI_ENABLE_OFFSET		0x08
+
+#define PCIE_TRANS_TABLE_BASE_REG	0x800
+#define PCIE_ATR_SRC_ADDR_MSB_OFFSET	0x4
+#define PCIE_ATR_TRSL_ADDR_LSB_OFFSET	0x8
+#define PCIE_ATR_TRSL_ADDR_MSB_OFFSET	0xc
+#define PCIE_ATR_TRSL_PARAM_OFFSET	0x10
+#define PCIE_ATR_TLB_SET_OFFSET		0x20
+
+#define PCIE_MAX_TRANS_TABLES		8
+#define ATR_EN				BIT(0)
+#define ATR_SIZE(size)			((((size) - 1) << 1) & GENMASK(6, 1))
+#define ATR_ID(id)			(id & GENMASK(3, 0))
+#define ATR_PARAM(param)		(((param) << 16) & GENMASK(27, 16))
+
+/**
+ * struct mtk_pcie_msi - MSI information for each set
+ * @base: IO mapped register base
+ * @hwirq: Hardware interrupt number
+ * @irq: MSI set Interrupt number
+ * @index: MSI set number
+ * @msg_addr: MSI message address
+ * @domain: IRQ domain
+ */
+struct mtk_pcie_msi {
+	void __iomem *base;
+	int hwirq;
+	int irq;
+	int index;
+	phys_addr_t msg_addr;
+	struct irq_domain *domain;
+};
+
+/**
+ * struct mtk_pcie_port - PCIe port information
+ * @dev: PCIe device
+ * @base: IO mapped register base
+ * @reg_base: Physical register base
+ * @mac_reset: mac reset control
+ * @phy_reset: phy reset control
+ * @phy: PHY controller block
+ * @clks: PCIe clocks
+ * @num_clks: PCIe clocks count for this port
+ * @is_suspended: device suspend state
+ * @irq: PCIe controller interrupt number
+ * @intx_domain: legacy INTx IRQ domain
+ * @msi_domain: MSI IRQ domain
+ * @msi_top_domain: MSI IRQ top domain
+ * @msi_info: MSI sets information
+ * @lock: lock protecting IRQ bit map
+ * @msi_irq_in_use: bit map for assigned MSI IRQ
+ */
+struct mtk_pcie_port {
+	struct device *dev;
+	void __iomem *base;
+	phys_addr_t reg_base;
+	struct reset_control *mac_reset;
+	struct reset_control *phy_reset;
+	struct phy *phy;
+	struct clk_bulk_data *clks;
+	int num_clks;
+	bool is_suspended;
+
+	int irq;
+	struct irq_domain *intx_domain;
+	struct irq_domain *msi_domain;
+	struct irq_domain *msi_top_domain;
+	struct mtk_pcie_msi **msi_info;
+	struct mutex lock;
+	DECLARE_BITMAP(msi_irq_in_use, PCIE_MSI_IRQS_NUM);
+};
+
+static int mtk_pcie_config_read(struct pci_bus *bus, unsigned int devfn,
+				    int where, int size, u32 *val)
+{
+	struct mtk_pcie_port *port = bus->sysdata;
+	int bytes;
+
+	bytes = ((1 << size) - 1) << (where & 0x3);
+	writel(PCIE_CFG_HEADER_FORCE_BE(devfn, bus->number, bytes),
+	       port->base + PCIE_CFGNUM_REG);
+
+	*val = readl(port->base + PCIE_CFG_OFFSET_ADDR + (where & ~0x3));
+
+	if (size <= 2)
+		*val = (*val >> (8 * (where & 0x3))) & ((1 << (size * 8)) - 1);
+
+	return PCIBIOS_SUCCESSFUL;
+}
+
+static int mtk_pcie_config_write(struct pci_bus *bus, unsigned int devfn,
+				     int where, int size, u32 val)
+{
+	struct mtk_pcie_port *port = bus->sysdata;
+	int bytes;
+
+	bytes = ((1 << size) - 1) << (where & 0x3);
+	writel(PCIE_CFG_HEADER_FORCE_BE(devfn, bus->number, bytes),
+	       port->base + PCIE_CFGNUM_REG);
+
+	if (size <= 2)
+		val = (val & ((1 << (size * 8)) - 1)) << ((where & 0x3) * 8);
+
+	writel(val, port->base + PCIE_CFG_OFFSET_ADDR + (where & ~0x3));
+
+	return PCIBIOS_SUCCESSFUL;
+}
+
+static struct pci_ops mtk_pcie_ops = {
+	.read  = mtk_pcie_config_read,
+	.write = mtk_pcie_config_write,
+};
+
+static void mtk_pcie_set_trans_window(void __iomem *reg,
+				      resource_size_t cpu_addr,
+				      resource_size_t pci_addr, size_t size)
+{
+	writel(lower_32_bits(cpu_addr) | ATR_SIZE(fls(size) - 1) | ATR_EN, reg);
+	writel(upper_32_bits(cpu_addr), reg + PCIE_ATR_SRC_ADDR_MSB_OFFSET);
+	writel(lower_32_bits(pci_addr), reg + PCIE_ATR_TRSL_ADDR_LSB_OFFSET);
+	writel(upper_32_bits(pci_addr), reg + PCIE_ATR_TRSL_ADDR_MSB_OFFSET);
+	writel(ATR_ID(0) | ATR_PARAM(0), reg + PCIE_ATR_TRSL_PARAM_OFFSET);
+}
+
+static int mtk_pcie_set_trans_table(void __iomem *reg,
+				    resource_size_t cpu_addr,
+				    resource_size_t pci_addr, size_t size,
+				    int num)
+{
+	void __iomem *table_base;
+
+	if (num > PCIE_MAX_TRANS_TABLES)
+		return -ENODEV;
+
+	table_base = reg + num * PCIE_ATR_TLB_SET_OFFSET;
+	mtk_pcie_set_trans_window(table_base, cpu_addr, pci_addr, size);
+
+	return 0;
+}
+
+static int mtk_pcie_startup_port(struct mtk_pcie_port *port)
+{
+	struct resource_entry *entry;
+	struct pci_host_bridge *host = pci_host_bridge_from_priv(port);
+	u32 val;
+	int err = 0, table_index = 0;
+
+	/* Set as RC mode */
+	val = readl(port->base + PCIE_SETTING_REG);
+	val |= PCIE_RC_MODE;
+	writel(val, port->base + PCIE_SETTING_REG);
+
+	/* Set class code */
+	val = readl(port->base + PCIE_PCI_IDS_1);
+	val &= ~GENMASK(31, 8);
+	val |= PCI_CLASS(PCI_CLASS_BRIDGE_PCI << 8);
+	writel(val, port->base + PCIE_PCI_IDS_1);
+
+	/* Assert all reset signals */
+	val = readl(port->base + PCIE_RST_CTRL_REG);
+	val |= PCIE_MAC_RSTB | PCIE_PHY_RSTB | PCIE_BRG_RSTB | PCIE_PE_RSTB;
+	writel(val, port->base + PCIE_RST_CTRL_REG);
+
+	/* De-assert reset signals*/
+	val &= ~(PCIE_MAC_RSTB | PCIE_PHY_RSTB | PCIE_BRG_RSTB);
+	writel(val, port->base + PCIE_RST_CTRL_REG);
+
+	/* Delay 100ms to wait the reference clocks become stable */
+	usleep_range(100 * 1000, 120 * 1000);
+
+	/* De-assert pe reset*/
+	val &= ~PCIE_PE_RSTB;
+	writel(val, port->base + PCIE_RST_CTRL_REG);
+
+	/* Check if the link is up or not */
+	err = readl_poll_timeout(port->base + PCIE_LINK_STATUS_REG, val,
+			!!(val & PCIE_PORT_LINKUP), 20,
+			50 * USEC_PER_MSEC);
+	if (err)
+		return err;
+
+	/* Set PCIe translation windows */
+	resource_list_for_each_entry(entry, &host->windows) {
+		unsigned long type = resource_type(entry->res);
+		struct resource *res = NULL;
+		resource_size_t cpu_addr;
+		resource_size_t pci_addr;
+
+		if (!(type & (IORESOURCE_MEM | IORESOURCE_IO)))
+			continue;
+
+		res = entry->res;
+		cpu_addr = res->start;
+		pci_addr = res->start - entry->offset;
+		mtk_pcie_set_trans_table(port->base + PCIE_TRANS_TABLE_BASE_REG,
+					 cpu_addr, pci_addr, resource_size(res),
+					 table_index);
+
+		dev_dbg(port->dev, "Set %s trans window[%d]: cpu_addr = %#llx, pci_addr = %#llx, size = %#llx\n",
+			(!!(type & IORESOURCE_MEM) ? "MEM" : "IO"), table_index,
+			cpu_addr, pci_addr, resource_size(res));
+
+		table_index++;
+	}
+
+	return 0;
+}
+
+static inline struct mtk_pcie_msi *mtk_get_msi_info(struct mtk_pcie_port *port,
+					     unsigned int hwirq)
+{
+	return port->msi_info[hwirq / PCIE_MSI_IRQS_PER_SET];
+}
+
+static int mtk_pcie_set_affinity(struct irq_data *data,
+				 const struct cpumask *mask, bool force)
+{
+	struct mtk_pcie_port *port = irq_data_get_irq_chip_data(data);
+	int ret;
+
+	ret = irq_set_affinity_hint(port->irq, mask);
+	if (ret)
+		return ret;
+
+	irq_data_update_effective_affinity(data, mask);
+
+	return 0;
+}
+
+static void mtk_compose_msi_msg(struct irq_data *data, struct msi_msg *msg)
+{
+	struct mtk_pcie_msi *msi_info;
+	struct mtk_pcie_port *port = irq_data_get_irq_chip_data(data);
+
+	msi_info = mtk_get_msi_info(port, data->hwirq);
+
+	msg->address_hi = 0;
+	msg->address_lo = lower_32_bits(msi_info->msg_addr);
+
+	msg->data = data->hwirq;
+	dev_dbg(port->dev, "msi#%#lx address_hi %#x address_lo %#x data %d\n",
+		data->hwirq, msg->address_hi, msg->address_lo, msg->data);
+}
+
+static void mtk_msi_irq_ack(struct irq_data *data)
+{
+	struct mtk_pcie_msi *msi_info;
+	struct mtk_pcie_port *port = irq_data_get_irq_chip_data(data);
+	int hwirq;
+
+	msi_info = mtk_get_msi_info(port, data->hwirq);
+
+	hwirq =	data->hwirq % PCIE_MSI_IRQS_PER_SET;
+
+	writel(1 << hwirq, msi_info->base + PCIE_MSI_STATUS_OFFSET);
+}
+
+static void mtk_msi_irq_mask(struct irq_data *data)
+{
+	struct mtk_pcie_msi *msi_info;
+	struct mtk_pcie_port *port = irq_data_get_irq_chip_data(data);
+	int val;
+
+	msi_info = mtk_get_msi_info(port, data->hwirq);
+	val = readl(msi_info->base + PCIE_MSI_ENABLE_OFFSET);
+	val &= ~(1 << data->hwirq);
+	writel(val, msi_info->base + PCIE_MSI_ENABLE_OFFSET);
+
+	pci_msi_mask_irq(data);
+}
+
+static void mtk_msi_irq_unmask(struct irq_data *data)
+{
+	struct mtk_pcie_msi *msi_info;
+	struct mtk_pcie_port *port = irq_data_get_irq_chip_data(data);
+	int val;
+
+	msi_info = mtk_get_msi_info(port, data->hwirq);
+	val = readl(msi_info->base + PCIE_MSI_ENABLE_OFFSET);
+	val |= (1 << data->hwirq);
+	writel(val, msi_info->base + PCIE_MSI_ENABLE_OFFSET);
+
+	pci_msi_unmask_irq(data);
+}
+
+static struct irq_chip mtk_msi_irq_chip = {
+	.irq_ack		= mtk_msi_irq_ack,
+	.irq_compose_msi_msg	= mtk_compose_msi_msg,
+	.irq_mask		= mtk_msi_irq_mask,
+	.irq_unmask		= mtk_msi_irq_unmask,
+	.irq_set_affinity	= mtk_pcie_set_affinity,
+	.name			= "PCIe",
+};
+
+static irq_hw_number_t mtk_pcie_msi_get_hwirq(struct msi_domain_info *info,
+					      msi_alloc_info_t *arg)
+{
+	struct msi_desc *entry = arg->desc;
+	struct mtk_pcie_port *port = info->chip_data;
+	int hwirq;
+
+	mutex_lock(&port->lock);
+
+	hwirq = bitmap_find_free_region(port->msi_irq_in_use, PCIE_MSI_IRQS_NUM,
+			order_base_2(entry->nvec_used));
+	if (hwirq < 0) {
+		mutex_unlock(&port->lock);
+		return -ENOSPC;
+	}
+
+	mutex_unlock(&port->lock);
+
+	return hwirq;
+}
+
+static void mtk_pcie_msi_free(struct irq_domain *domain,
+			      struct msi_domain_info *info, unsigned int virq)
+{
+	struct irq_data *data = irq_domain_get_irq_data(domain, virq);
+	struct mtk_pcie_port *port = irq_data_get_irq_chip_data(data);
+
+	mutex_lock(&port->lock);
+
+	bitmap_clear(port->msi_irq_in_use, data->hwirq, 1);
+
+	mutex_unlock(&port->lock);
+}
+
+static struct msi_domain_ops mtk_msi_domain_ops = {
+	.get_hwirq	= mtk_pcie_msi_get_hwirq,
+	.msi_free	= mtk_pcie_msi_free,
+};
+
+static struct msi_domain_info mtk_msi_domain_info = {
+	.flags		= (MSI_FLAG_USE_DEF_DOM_OPS | MSI_FLAG_PCI_MSIX |
+			   MSI_FLAG_USE_DEF_CHIP_OPS | MSI_FLAG_MULTI_PCI_MSI),
+	.chip		= &mtk_msi_irq_chip,
+	.ops		= &mtk_msi_domain_ops,
+	.handler	= handle_edge_irq,
+	.handler_name	= "MSI",
+};
+
+static void mtk_msi_top_irq_eoi(struct irq_data *data)
+{
+	struct mtk_pcie_port *port = irq_data_get_irq_chip_data(data);
+	int msi_irq = data->hwirq + PCIE_MSI_SHIFT;
+
+	writel(1 << msi_irq, port->base + PCIE_INT_STATUS_REG);
+}
+
+static struct irq_chip mtk_msi_top_irq_chip = {
+	.irq_eoi	= mtk_msi_top_irq_eoi,
+	.name		= "PCIe",
+};
+
+static void mtk_pcie_msi_handler(struct irq_desc *desc)
+{
+	struct mtk_pcie_msi *msi_info = irq_desc_get_handler_data(desc);
+	struct irq_chip *irqchip = irq_desc_get_chip(desc);
+	unsigned long msi_enable, msi_status;
+	u32 virq, bit, hwirq;
+
+	chained_irq_enter(irqchip, desc);
+
+	msi_enable = readl(msi_info->base + PCIE_MSI_ENABLE_OFFSET);
+	while ((msi_status = readl(msi_info->base + PCIE_MSI_STATUS_OFFSET))) {
+		msi_status &= msi_enable;
+		for_each_set_bit(bit, &msi_status, PCIE_MSI_IRQS_PER_SET) {
+			hwirq = bit + msi_info->index * PCIE_MSI_IRQS_PER_SET;
+			virq = irq_find_mapping(msi_info->domain, hwirq);
+			generic_handle_irq(virq);
+		}
+	}
+
+	chained_irq_exit(irqchip, desc);
+}
+
+static int mtk_msi_top_domain_map(struct irq_domain *domain,
+				    unsigned int virq, irq_hw_number_t hwirq)
+{
+	struct mtk_pcie_port *port = domain->host_data;
+	struct mtk_pcie_msi *msi_info = port->msi_info[hwirq];
+
+	irq_domain_set_info(domain, virq, hwirq,
+			    &mtk_msi_top_irq_chip, domain->host_data,
+			    mtk_pcie_msi_handler, msi_info, NULL);
+
+	return 0;
+}
+
+static const struct irq_domain_ops mtk_msi_top_domain_ops = {
+	.map = mtk_msi_top_domain_map,
+};
+
+static void mtk_intx_mask(struct irq_data *data)
+{
+	struct mtk_pcie_port *port = irq_data_get_irq_chip_data(data);
+	int val;
+
+	val = readl(port->base + PCIE_INT_ENABLE_REG);
+	val &= ~(1 << (data->hwirq + PCIE_INTX_SHIFT));
+	writel(val, port->base + PCIE_INT_ENABLE_REG);
+}
+
+static void mtk_intx_unmask(struct irq_data *data)
+{
+	struct mtk_pcie_port *port = irq_data_get_irq_chip_data(data);
+	int val;
+
+	val = readl(port->base + PCIE_INT_ENABLE_REG);
+	val |= 1 << (data->hwirq + PCIE_INTX_SHIFT);
+	writel(val, port->base + PCIE_INT_ENABLE_REG);
+}
+
+static void mtk_intx_eoi(struct irq_data *data)
+{
+	struct mtk_pcie_port *port = irq_data_get_irq_chip_data(data);
+	int hwirq;
+
+	/**
+	 * As an emulated level irq, its interrupt status will be remained
+	 * until receive the corresponding message of de-assert, hence that
+	 * the status can only be cleared when the interrupt has been serviced.
+	 */
+	hwirq = data->hwirq + PCIE_INTX_SHIFT;
+	writel(1 << hwirq, port->base + PCIE_INT_STATUS_REG);
+}
+
+static struct irq_chip mtk_intx_irq_chip = {
+	.irq_mask		= mtk_intx_mask,
+	.irq_unmask		= mtk_intx_unmask,
+	.irq_eoi		= mtk_intx_eoi,
+	.irq_set_affinity	= mtk_pcie_set_affinity,
+	.name			= "PCIe",
+};
+
+static int mtk_pcie_intx_map(struct irq_domain *domain, unsigned int irq,
+			     irq_hw_number_t hwirq)
+{
+	irq_set_chip_and_handler_name(irq, &mtk_intx_irq_chip,
+				      handle_fasteoi_irq, "INTx");
+	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_domains(struct mtk_pcie_port *port,
+				     struct device_node *node)
+{
+	struct device *dev = port->dev;
+	struct device_node *intc_node;
+	struct fwnode_handle *fwnode = of_node_to_fwnode(node);
+	struct mtk_pcie_msi *msi_info;
+	struct msi_domain_info *info;
+	int i, val, ret;
+
+	/* Setup INTx */
+	intc_node = of_get_child_by_name(node, "interrupt-controller");
+	if (!intc_node) {
+		dev_notice(dev, "Missing PCIe Intc node\n");
+		return -ENODEV;
+	}
+
+	port->intx_domain = irq_domain_add_linear(intc_node, PCI_NUM_INTX,
+						  &intx_domain_ops, port);
+	if (!port->intx_domain) {
+		dev_notice(dev, "failed to get INTx IRQ domain\n");
+		return -ENODEV;
+	}
+
+	/* Setup MSI */
+	mutex_init(&port->lock);
+
+	info = devm_kzalloc(dev, sizeof(*info), GFP_KERNEL);
+	if (!info)
+		return -ENOMEM;
+
+	memcpy(info, &mtk_msi_domain_info, sizeof(*info));
+	info->chip_data = port;
+
+	port->msi_domain = pci_msi_create_irq_domain(fwnode, info, NULL);
+	if (!port->msi_domain) {
+		dev_info(dev, "failed to create msi domain\n");
+		ret = -ENODEV;
+		goto err_msi_domain;
+	}
+
+	/* Enable MSI and setup pcie domains */
+	port->msi_top_domain = irq_domain_add_hierarchy(NULL, 0, 0, node,
+							&mtk_msi_top_domain_ops,
+							port);
+	if (!port->msi_top_domain) {
+		dev_info(dev, "failed to create msi top domain\n");
+		ret = -ENODEV;
+		goto err_msi_top_domain;
+	}
+
+	port->msi_info = devm_kzalloc(dev, PCIE_MSI_SET_NUM, GFP_KERNEL);
+	if (!port->msi_info) {
+		ret = -ENOMEM;
+		goto err_msi_info;
+	}
+
+	for (i = 0; i < PCIE_MSI_SET_NUM; i++) {
+		int offset = i * PCIE_MSI_SET_OFFSET;
+
+		msi_info = devm_kzalloc(dev, sizeof(*msi_info), GFP_KERNEL);
+		if (!msi_info) {
+			ret = -ENOMEM;
+			goto err_msi_set;
+		}
+
+		msi_info->base = port->base + PCIE_MSI_ADDR_BASE_REG + offset;
+		msi_info->msg_addr = port->reg_base + PCIE_MSI_ADDR_BASE_REG +
+				     offset;
+
+		writel(lower_32_bits(msi_info->msg_addr), msi_info->base);
+
+		msi_info->hwirq = i;
+		msi_info->index = i;
+		msi_info->domain = port->msi_domain;
+
+		port->msi_info[i] = msi_info;
+
+		/* Alloc irq for each msi set */
+		msi_info->irq = irq_create_mapping(port->msi_top_domain, i);
+		if (msi_info->irq < 0) {
+			dev_info(dev, "allocate msi top irq failed\n");
+			ret = -ENOSPC;
+			goto err_msi_set;
+		}
+
+		val = readl(port->base + PCIE_INT_ENABLE_REG);
+		val |= (1 << (i + PCIE_MSI_SHIFT));
+		writel(val, port->base + PCIE_INT_ENABLE_REG);
+
+		val = readl(port->base + PCIE_MSI_SET_ENABLE_REG);
+		val |= (1 << i);
+		writel(val, port->base + PCIE_MSI_SET_ENABLE_REG);
+	}
+
+	return 0;
+
+err_msi_set:
+	while (--i >= 0) {
+		msi_info = port->msi_info[i];
+		irq_dispose_mapping(msi_info->irq);
+	}
+err_msi_info:
+	irq_domain_remove(port->msi_top_domain);
+err_msi_top_domain:
+	irq_domain_remove(port->msi_domain);
+err_msi_domain:
+	irq_domain_remove(port->intx_domain);
+
+	return ret;
+}
+
+static void mtk_pcie_irq_teardown(struct mtk_pcie_port *port)
+{
+	struct mtk_pcie_msi *msi_info;
+	int i;
+
+	irq_set_chained_handler_and_data(port->irq, NULL, NULL);
+
+	if (port->intx_domain)
+		irq_domain_remove(port->intx_domain);
+
+	if (port->msi_domain)
+		irq_domain_remove(port->msi_domain);
+
+	if (port->msi_top_domain) {
+		for (i = 0; i < PCIE_MSI_SET_NUM; i++) {
+			msi_info = port->msi_info[i];
+			irq_dispose_mapping(msi_info->irq);
+		}
+
+		irq_domain_remove(port->msi_top_domain);
+	}
+
+	irq_dispose_mapping(port->irq);
+}
+
+static void mtk_pcie_irq_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 irq_bit = PCIE_INTX_SHIFT;
+
+	chained_irq_enter(irqchip, desc);
+
+	status = readl(port->base + PCIE_INT_STATUS_REG);
+	if (status & PCIE_INTX_MASK) {
+		for_each_set_bit_from(irq_bit, &status, PCI_NUM_INTX +
+				      PCIE_INTX_SHIFT) {
+			virq = irq_find_mapping(port->intx_domain,
+						irq_bit - PCIE_INTX_SHIFT);
+			generic_handle_irq(virq);
+		}
+	}
+
+	if (status & PCIE_MSI_MASK) {
+		irq_bit = PCIE_MSI_SHIFT;
+		for_each_set_bit_from(irq_bit, &status, PCIE_MSI_SET_NUM +
+				      PCIE_MSI_SHIFT) {
+			virq = irq_find_mapping(port->msi_top_domain,
+						irq_bit - PCIE_MSI_SHIFT);
+			generic_handle_irq(virq);
+		}
+	}
+
+	chained_irq_exit(irqchip, desc);
+}
+
+static int mtk_pcie_setup_irq(struct mtk_pcie_port *port,
+			      struct device_node *node)
+{
+	struct device *dev = port->dev;
+	struct platform_device *pdev = to_platform_device(dev);
+	int err;
+
+	err = mtk_pcie_init_irq_domains(port, node);
+	if (err) {
+		dev_notice(dev, "failed to init PCIe IRQ domain\n");
+		return err;
+	}
+
+	port->irq = platform_get_irq(pdev, 0);
+	if (port->irq < 0)
+		return port->irq;
+
+	irq_set_chained_handler_and_data(port->irq, mtk_pcie_irq_handler, port);
+
+	return 0;
+}
+
+static int mtk_pcie_clk_init(struct mtk_pcie_port *port)
+{
+	int ret;
+
+	port->num_clks = devm_clk_bulk_get_all(port->dev, &port->clks);
+	if (port->num_clks < 0) {
+		dev_notice(port->dev, "failed to get pcie clock\n");
+		return port->num_clks;
+	}
+
+	ret = clk_bulk_prepare_enable(port->num_clks, port->clks);
+	if (ret) {
+		dev_notice(port->dev, "failed to enable pcie clocks\n");
+		return ret;
+	}
+
+	return 0;
+}
+
+static int mtk_pcie_power_up(struct mtk_pcie_port *port)
+{
+	struct device *dev = port->dev;
+	int err;
+
+	port->phy_reset = devm_reset_control_get_optional_exclusive(dev,
+								    "phy-rst");
+	if (IS_ERR(port->phy_reset))
+		return PTR_ERR(port->phy_reset);
+
+	reset_control_deassert(port->phy_reset);
+
+	/* PHY power on and enable pipe clock */
+	port->phy = devm_phy_optional_get(dev, "pcie-phy");
+	if (IS_ERR(port->phy))
+		return PTR_ERR(port->phy);
+
+	err = phy_init(port->phy);
+	if (err) {
+		dev_notice(dev, "failed to initialize pcie phy\n");
+		return err;
+	}
+
+	err = phy_power_on(port->phy);
+	if (err) {
+		dev_notice(dev, "failed to power on pcie phy\n");
+		goto err_phy_on;
+	}
+
+	port->mac_reset = devm_reset_control_get_optional_exclusive(dev,
+								    "mac-rst");
+	if (IS_ERR(port->mac_reset))
+		return PTR_ERR(port->mac_reset);
+
+	reset_control_deassert(port->mac_reset);
+
+	/* MAC power on and enable transaction layer clocks */
+	pm_runtime_enable(dev);
+	pm_runtime_get_sync(dev);
+
+	err = mtk_pcie_clk_init(port);
+	if (err) {
+		dev_notice(dev, "clock init failed\n");
+		goto err_clk_init;
+	}
+
+	return 0;
+
+err_clk_init:
+	pm_runtime_put_sync(dev);
+	pm_runtime_disable(dev);
+	reset_control_assert(port->mac_reset);
+	phy_power_off(port->phy);
+err_phy_on:
+	phy_exit(port->phy);
+	reset_control_assert(port->phy_reset);
+
+	return -EBUSY;
+}
+
+static void mtk_pcie_power_down(struct mtk_pcie_port *port)
+{
+	phy_power_off(port->phy);
+	phy_exit(port->phy);
+
+	clk_bulk_disable_unprepare(port->num_clks, port->clks);
+
+	pm_runtime_put_sync(port->dev);
+	pm_runtime_disable(port->dev);
+}
+
+static int mtk_pcie_setup(struct mtk_pcie_port *port)
+{
+	struct device *dev = port->dev;
+	struct platform_device *pdev = to_platform_device(dev);
+	struct resource *regs;
+	int err;
+
+	regs = platform_get_resource_byname(pdev, IORESOURCE_MEM, "pcie-mac");
+	port->base = devm_ioremap_resource(dev, regs);
+	if (IS_ERR(port->base)) {
+		dev_notice(dev, "failed to map register base\n");
+		return PTR_ERR(port->base);
+	}
+
+	port->reg_base = regs->start;
+
+	/* Don't touch the hardware registers before power up */
+	err = mtk_pcie_power_up(port);
+	if (err)
+		return err;
+
+	/* Try link up */
+	err = mtk_pcie_startup_port(port);
+	if (err) {
+		dev_notice(dev, "PCIe link down\n");
+		goto err_setup;
+	}
+
+	err = mtk_pcie_setup_irq(port, dev->of_node);
+	if (err)
+		goto err_setup;
+
+	dev_info(dev, "PCIe link up success!\n");
+
+	return 0;
+
+err_setup:
+	mtk_pcie_power_down(port);
+
+	return err;
+}
+
+static int mtk_pcie_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct mtk_pcie_port *port;
+	struct pci_host_bridge *host;
+	int err;
+
+	host = devm_pci_alloc_host_bridge(dev, sizeof(*port));
+	if (!host)
+		return -ENOMEM;
+
+	port = pci_host_bridge_priv(host);
+
+	port->dev = dev;
+	platform_set_drvdata(pdev, port);
+
+	err = mtk_pcie_setup(port);
+	if (err)
+		return err;
+
+	host->ops = &mtk_pcie_ops;
+	host->sysdata = port;
+
+	err = pci_host_probe(host);
+	if (err) {
+		mtk_pcie_power_down(port);
+		return err;
+	}
+
+	return 0;
+}
+
+static int mtk_pcie_remove(struct platform_device *pdev)
+{
+	struct mtk_pcie_port *port = platform_get_drvdata(pdev);
+	struct pci_host_bridge *host = pci_host_bridge_from_priv(port);
+
+	pci_lock_rescan_remove();
+	pci_stop_root_bus(host->bus);
+	pci_remove_root_bus(host->bus);
+	pci_unlock_rescan_remove();
+
+	mtk_pcie_irq_teardown(port);
+	mtk_pcie_power_down(port);
+
+	return 0;
+}
+
+static int __maybe_unused mtk_pcie_turn_off_link(struct mtk_pcie_port *port)
+{
+	int val;
+
+	val = readl(port->base + PCIE_ICMD_PM_REG);
+	val |= PCIE_TURN_OFF_LINK;
+	writel(val, port->base + PCIE_ICMD_PM_REG);
+
+	/* Check the link is L2 */
+	return readl_poll_timeout(port->base + PCIE_LTSSM_STATUS_REG, val,
+				  (PCIE_LTSSM_STATE(val) ==
+				   PCIE_LTSSM_STATE_L2_IDLE), 20,
+				   50 * USEC_PER_MSEC);
+}
+
+static int __maybe_unused mtk_pcie_suspend_noirq(struct device *dev)
+{
+	struct mtk_pcie_port *port = dev_get_drvdata(dev);
+	int err, val;
+
+	if (port->is_suspended)
+		return 0;
+
+	/* Trigger link to L2 state */
+	err = mtk_pcie_turn_off_link(port);
+	if (err) {
+		dev_notice(port->dev, "can not enter L2 state\n");
+		goto power_off;
+	}
+
+	/* Pull down the PERST# pin */
+	val = readl(port->base + PCIE_RST_CTRL_REG);
+	val |= PCIE_PE_RSTB;
+	writel(val, port->base + PCIE_RST_CTRL_REG);
+
+	dev_info(port->dev, "enter L2 state success");
+
+power_off:
+	phy_power_off(port->phy);
+
+	clk_bulk_disable_unprepare(port->num_clks, port->clks);
+
+	port->is_suspended = true;
+
+	return 0;
+}
+
+static int __maybe_unused mtk_pcie_resume_noirq(struct device *dev)
+{
+	struct mtk_pcie_port *port = dev_get_drvdata(dev);
+	int err;
+
+	if (!port->is_suspended)
+		return 0;
+
+	phy_power_on(port->phy);
+
+	err = clk_bulk_prepare_enable(port->num_clks, port->clks);
+	if (err) {
+		dev_dbg(dev, "failed to enable pcie clocks\n");
+		return err;
+	}
+
+	err = mtk_pcie_startup_port(port);
+	if (err) {
+		dev_notice(port->dev, "resume failed\n");
+		return err;
+	}
+
+	port->is_suspended = false;
+
+	dev_info(port->dev, "resume done\n");
+
+	return 0;
+}
+
+static const struct dev_pm_ops mtk_pcie_pm_ops = {
+	SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(mtk_pcie_suspend_noirq,
+				      mtk_pcie_resume_noirq)
+};
+
+static const struct of_device_id mtk_pcie_of_match[] = {
+	{ .compatible = "mediatek,gen3-pcie" },
+	{ .compatible = "mediatek,mt8192-pcie" },
+	{},
+};
+
+static struct platform_driver mtk_pcie_driver = {
+	.probe = mtk_pcie_probe,
+	.remove = mtk_pcie_remove,
+	.driver = {
+		.name = "mtk-pcie",
+		.of_match_table = mtk_pcie_of_match,
+		.pm = &mtk_pcie_pm_ops,
+	},
+};
+
+module_platform_driver(mtk_pcie_driver);
+MODULE_LICENSE("GPL v2");
-- 
2.25.1