// SPDX-License-Identifier: GPL-2.0
/*
 * MediaTek PCIe host controller driver.
 *
 * Copyright (c) 2020 MediaTek Inc.
 * Author: Jianjun Wang <jianjun.wang@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/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(bus, devfn) \
	(PCIE_CFG_BUS(bus) | PCIE_CFG_DEVFN(devfn))

#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_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_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_INT_STATUS_REG		0x184
#define PCIE_MSI_SET_ENABLE_REG		0x190

#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 PCIE_ATR_EN			BIT(0)
#define PCIE_ATR_SIZE(size) \
	(((((size) - 1) << 1) & GENMASK(6, 1)) | PCIE_ATR_EN)
#define PCIE_ATR_ID(id)			((id) & GENMASK(3, 0))
#define PCIE_ATR_TYPE_MEM		PCIE_ATR_ID(0)
#define PCIE_ATR_TYPE_IO		PCIE_ATR_ID(1)
#define PCIE_ATR_TLP_TYPE(type)		(((type) << 16) & GENMASK(18, 16))
#define PCIE_ATR_TLP_TYPE_MEM		PCIE_ATR_TLP_TYPE(0)
#define PCIE_ATR_TLP_TYPE_IO		PCIE_ATR_TLP_TYPE(2)

/**
 * struct mtk_pcie_msi - MSI information for each set
 * @base: IO mapped register base
 * @irq: MSI set Interrupt number
 * @index: MSI set number
 * @msg_addr: MSI message address
 * @domain: IRQ domain
 */
struct mtk_pcie_msi {
	void __iomem *base;
	unsigned 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
 * @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;
	unsigned int busnr;

	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);
};

/**
 * mtk_pcie_config_tlp_header
 * @bus: PCI bus to query
 * @devfn: device/function number
 * @where: offset in config space
 * @size: data size in TLP header
 *
 * Set byte enable field and device information in configuration TLP header.
 */
static void mtk_pcie_config_tlp_header(struct pci_bus *bus, unsigned int devfn,
					int where, int size)
{
	struct mtk_pcie_port *port = bus->sysdata;
	int bytes;
	u32 val;

	bytes = (GENMASK(size - 1, 0) & 0xf) << (where & 0x3);

	val = PCIE_CFG_FORCE_BYTE_EN | PCIE_CFG_BYTE_EN(bytes) |
	      PCIE_CFG_HEADER(bus->number, devfn);

	writel(val, port->base + PCIE_CFGNUM_REG);
}

static void __iomem *mtk_pcie_map_bus(struct pci_bus *bus, unsigned int devfn,
				      int where)
{
	struct mtk_pcie_port *port = bus->sysdata;

	return port->base + PCIE_CFG_OFFSET_ADDR + where;
}

static int mtk_pcie_config_read(struct pci_bus *bus, unsigned int devfn,
				int where, int size, u32 *val)
{
	mtk_pcie_config_tlp_header(bus, devfn, where, size);

	return pci_generic_config_read32(bus, devfn, where, size, val);
}

static int mtk_pcie_config_write(struct pci_bus *bus, unsigned int devfn,
				 int where, int size, u32 val)
{
	mtk_pcie_config_tlp_header(bus, devfn, where, size);

	if (size <= 2)
		val <<= (where & 0x3) * 8;

	return pci_generic_config_write32(bus, devfn, where, 4, val);
}

static struct pci_ops mtk_pcie_ops = {
	.map_bus = mtk_pcie_map_bus,
	.read  = mtk_pcie_config_read,
	.write = mtk_pcie_config_write,
};

static int mtk_pcie_set_trans_table(struct mtk_pcie_port *port,
				    resource_size_t cpu_addr,
				    resource_size_t pci_addr,
				    resource_size_t size,
				    unsigned long type, int num)
{
	void __iomem *table;
	u32 val = 0;

	if (num >= PCIE_MAX_TRANS_TABLES) {
		dev_notice(port->dev, "not enough translate table[%d] for addr: %#llx, limited to [%d]\n",
			   num, (unsigned long long) cpu_addr,
			   PCIE_MAX_TRANS_TABLES);
		return -ENODEV;
	}

	table = port->base + PCIE_TRANS_TABLE_BASE_REG +
		num * PCIE_ATR_TLB_SET_OFFSET;

	writel(lower_32_bits(cpu_addr) | PCIE_ATR_SIZE(fls(size) - 1), table);
	writel(upper_32_bits(cpu_addr), table + PCIE_ATR_SRC_ADDR_MSB_OFFSET);
	writel(lower_32_bits(pci_addr), table + PCIE_ATR_TRSL_ADDR_LSB_OFFSET);
	writel(upper_32_bits(pci_addr), table + PCIE_ATR_TRSL_ADDR_MSB_OFFSET);

	if (type == IORESOURCE_IO)
		val = PCIE_ATR_TYPE_IO | PCIE_ATR_TLP_TYPE_IO;
	else
		val = PCIE_ATR_TYPE_MEM | PCIE_ATR_TLP_TYPE_MEM;

	writel(val, table + PCIE_ATR_TRSL_PARAM_OFFSET);

	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);
	unsigned int table_index = 0;
	int err;
	u32 val;

	/* 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 PERST# signal */
	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) {
		val = readl(port->base + PCIE_LTSSM_STATUS_REG);
		dev_notice(port->dev, "PCIe link down, ltssm reg val: %#x\n",
			   val);
		return err;
	}

	/* Set PCIe translation windows */
	resource_list_for_each_entry(entry, &host->windows) {
		struct resource *res = entry->res;
		unsigned long type = resource_type(res);
		resource_size_t cpu_addr;
		resource_size_t pci_addr;
		resource_size_t size;
		const char *range_type;

		if (type == IORESOURCE_IO) {
			cpu_addr = pci_pio_to_address(res->start);
			range_type = "IO";
		} else if (type == IORESOURCE_MEM) {
			cpu_addr = res->start;
			range_type = "MEM";
		} else {
			continue;
		}

		pci_addr = res->start - entry->offset;
		size = resource_size(res);
		err = mtk_pcie_set_trans_table(port, cpu_addr, pci_addr, size,
					       type, table_index);
		if (err)
			return err;

		dev_dbg(port->dev, "set %s trans window[%d]: cpu_addr = %#llx, pci_addr = %#llx, size = %#llx\n",
			range_type, table_index, (unsigned long long) cpu_addr,
			(unsigned long long) pci_addr,
			(unsigned long long) size);

		table_index++;
	}

	return 0;
}

static inline struct mtk_pcie_msi *mtk_get_msi_info(struct mtk_pcie_port *port,
						    unsigned long 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);
	struct irq_data *port_data = irq_get_irq_data(port->irq);
	struct irq_chip *port_chip = irq_data_get_irq_chip(port_data);
	int ret;

	if (!port_chip || !port_chip->irq_set_affinity)
		return -EINVAL;

	ret = port_chip->irq_set_affinity(port_data, mask, force);

	irq_data_update_effective_affinity(data, mask);

	return ret;
}

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);
	unsigned long hwirq;

	msi_info = mtk_get_msi_info(port, data->hwirq);
	hwirq =	data->hwirq % PCIE_MSI_IRQS_PER_SET;

	msg->address_hi = 0;
	msg->address_lo = lower_32_bits(msi_info->msg_addr);
	msg->data = hwirq;
	dev_dbg(port->dev, "msi#%#lx address_hi %#x address_lo %#x data %d\n",
		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);
	unsigned long hwirq;

	msi_info = mtk_get_msi_info(port, data->hwirq);
	hwirq =	data->hwirq % PCIE_MSI_IRQS_PER_SET;

	writel(BIT(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);
	unsigned long hwirq;
	u32 val;

	msi_info = mtk_get_msi_info(port, data->hwirq);
	hwirq =	data->hwirq % PCIE_MSI_IRQS_PER_SET;

	val = readl(msi_info->base + PCIE_MSI_ENABLE_OFFSET);
	val &= ~BIT(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);
	unsigned long hwirq;
	u32 val;

	msi_info = mtk_get_msi_info(port, data->hwirq);
	hwirq =	data->hwirq % PCIE_MSI_IRQS_PER_SET;

	val = readl(msi_info->base + PCIE_MSI_ENABLE_OFFSET);
	val |= BIT(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);
	unsigned long msi_irq = data->hwirq + PCIE_MSI_SHIFT;

	writel(BIT(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;
	unsigned int virq;
	irq_hw_number_t 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);
	u32 val;

	val = readl(port->base + PCIE_INT_ENABLE_REG);
	val &= ~BIT(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);
	u32 val;

	val = readl(port->base + PCIE_INT_ENABLE_REG);
	val |= BIT(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);
	unsigned long hwirq;

	/**
	 * As an emulated level IRQ, its interrupt status will remain
	 * until the corresponding de-assert message is received; hence that
	 * the status can only be cleared when the interrupt has been serviced.
	 */
	hwirq = data->hwirq + PCIE_INTX_SHIFT;
	writel(BIT(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, 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;
		u32 val;

		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->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) {
			dev_info(dev, "allocate MSI top IRQ failed\n");
			ret = -ENOSPC;
			goto err_msi_set;
		}

		val = readl(port->base + PCIE_INT_ENABLE_REG);
		val |= BIT(i + PCIE_MSI_SHIFT);
		writel(val, port->base + PCIE_INT_ENABLE_REG);

		val = readl(port->base + PCIE_MSI_SET_ENABLE_REG);
		val |= BIT(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;
	unsigned int virq;
	irq_hw_number_t 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");
	if (IS_ERR(port->phy_reset))
		return PTR_ERR(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);

	reset_control_deassert(port->phy_reset);

	err = phy_power_on(port->phy);
	if (err) {
		dev_notice(dev, "failed to power on PCIe phy\n");
		goto err_phy_on;
	}

	err = phy_init(port->phy);
	if (err) {
		dev_notice(dev, "failed to initialize PCIe phy\n");
		goto err_phy_init;
	}

	port->mac_reset = devm_reset_control_get_optional_exclusive(dev, "mac");
	if (IS_ERR(port->mac_reset)) {
		err = PTR_ERR(port->mac_reset);
		goto err_mac_rst;
	}

	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);
err_mac_rst:
	phy_exit(port->phy);
err_phy_init:
	phy_power_off(port->phy);
err_phy_on:
	reset_control_assert(port->phy_reset);

	return err;
}

static void mtk_pcie_power_down(struct mtk_pcie_port *port)
{
	clk_bulk_disable_unprepare(port->num_clks, port->clks);

	pm_runtime_put_sync(port->dev);
	pm_runtime_disable(port->dev);
	reset_control_assert(port->mac_reset);

	phy_power_off(port->phy);
	phy_exit(port->phy);
	reset_control_assert(port->phy_reset);
}

static int mtk_pcie_setup(struct mtk_pcie_port *port)
{
	struct device *dev = port->dev;
	struct platform_device *pdev = to_platform_device(dev);
	struct pci_host_bridge *host = pci_host_bridge_from_priv(port);
	struct list_head *windows = &host->windows;
	struct resource *regs, *bus;
	int err;

	err = pci_parse_request_of_pci_ranges(dev, windows, &bus);
	if (err)
		return err;

	port->busnr = bus->start;

	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 startup failed\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 void release_io_range(struct device *dev)
{
	struct logic_pio_hwaddr *iorange = NULL;

	iorange = find_io_range_by_fwnode(&dev->of_node->fwnode);
	if (iorange) {
		logic_pio_unregister_range(iorange);
		kfree(iorange);
	}
}

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)
		goto release_resource;

	host->busnr = port->busnr;
	host->dev.parent = port->dev;
	host->map_irq = of_irq_parse_and_map_pci;
	host->swizzle_irq = pci_common_swizzle;
	host->ops = &mtk_pcie_ops;
	host->sysdata = port;

	err = pci_host_probe(host);
	if (err) {
		mtk_pcie_irq_teardown(port);
		mtk_pcie_power_down(port);
		goto release_resource;
	}

	return 0;

release_resource:
	release_io_range(dev);
	pci_free_resource_list(&host->windows);

	return err;
}

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)
{
	u32 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;
	u32 val;

	/* Trigger link to L2 state */
	err = mtk_pcie_turn_off_link(port);
	if (err) {
		dev_notice(port->dev, "can not enter L2 state\n");
		return err;
	}

	/* 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_dbg(port->dev, "enter L2 state success");

	clk_bulk_disable_unprepare(port->num_clks, port->clks);

	phy_power_off(port->phy);

	return 0;
}

static int __maybe_unused mtk_pcie_resume_noirq(struct device *dev)
{
	struct mtk_pcie_port *port = dev_get_drvdata(dev);
	int err;

	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;
	}

	dev_dbg(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,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");