/*
 * Synopsys Designware PCIe host controller driver
 *
 * Copyright (C) 2013 Samsung Electronics Co., Ltd.
 *		http://www.samsung.com
 *
 * Author: Jingoo Han <jg1.han@samsung.com>
 *
 * 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.
 */


#include <common.h>
#include <clock.h>
#include <malloc.h>
#include <io.h>
#include <init.h>
#include <asm/mmu.h>

#include <linux/clk.h>
#include <linux/kernel.h>
#include <of_address.h>
#include <of_pci.h>
#include <linux/pci.h>
#include <linux/phy/phy.h>
#include <linux/reset.h>
#include <linux/sizes.h>

#include "pcie-designware.h"

/* Synopsis specific PCIE configuration registers */
#define PCIE_PORT_LINK_CONTROL		0x710
#define PORT_LINK_MODE_MASK		(0x3f << 16)
#define PORT_LINK_MODE_1_LANES		(0x1 << 16)
#define PORT_LINK_MODE_2_LANES		(0x3 << 16)
#define PORT_LINK_MODE_4_LANES		(0x7 << 16)

#define PCIE_LINK_WIDTH_SPEED_CONTROL	0x80C
#define PORT_LOGIC_SPEED_CHANGE		(0x1 << 17)
#define PORT_LOGIC_LINK_WIDTH_MASK	(0x1ff << 8)
#define PORT_LOGIC_LINK_WIDTH_1_LANES	(0x1 << 8)
#define PORT_LOGIC_LINK_WIDTH_2_LANES	(0x2 << 8)
#define PORT_LOGIC_LINK_WIDTH_4_LANES	(0x4 << 8)

#define PCIE_MSI_ADDR_LO		0x820
#define PCIE_MSI_ADDR_HI		0x824
#define PCIE_MSI_INTR0_ENABLE		0x828
#define PCIE_MSI_INTR0_MASK		0x82C
#define PCIE_MSI_INTR0_STATUS		0x830

#define PCIE_ATU_VIEWPORT		0x900
#define PCIE_ATU_REGION_INBOUND		(0x1 << 31)
#define PCIE_ATU_REGION_OUTBOUND	(0x0 << 31)
#define PCIE_ATU_REGION_INDEX1		(0x1 << 0)
#define PCIE_ATU_REGION_INDEX0		(0x0 << 0)
#define PCIE_ATU_CR1			0x904
#define PCIE_ATU_TYPE_MEM		(0x0 << 0)
#define PCIE_ATU_TYPE_IO		(0x2 << 0)
#define PCIE_ATU_TYPE_CFG0		(0x4 << 0)
#define PCIE_ATU_TYPE_CFG1		(0x5 << 0)
#define PCIE_ATU_CR2			0x908
#define PCIE_ATU_ENABLE			(0x1 << 31)
#define PCIE_ATU_BAR_MODE_ENABLE	(0x1 << 30)
#define PCIE_ATU_LOWER_BASE		0x90C
#define PCIE_ATU_UPPER_BASE		0x910
#define PCIE_ATU_LIMIT			0x914
#define PCIE_ATU_LOWER_TARGET		0x918
#define PCIE_ATU_BUS(x)			(((x) & 0xff) << 24)
#define PCIE_ATU_DEV(x)			(((x) & 0x1f) << 19)
#define PCIE_ATU_FUNC(x)		(((x) & 0x7) << 16)
#define PCIE_ATU_UPPER_TARGET		0x91C

static unsigned long global_io_offset;

int dw_pcie_cfg_read(void __iomem *addr, int where, int size, u32 *val)
{
	*val = readl(addr);

	if (size == 1)
		*val = (*val >> (8 * (where & 3))) & 0xff;
	else if (size == 2)
		*val = (*val >> (8 * (where & 3))) & 0xffff;
	else if (size != 4)
		return PCIBIOS_BAD_REGISTER_NUMBER;

	return PCIBIOS_SUCCESSFUL;
}

int dw_pcie_cfg_write(void __iomem *addr, int where, int size, u32 val)
{
	if (size == 4)
		writel(val, addr);
	else if (size == 2)
		writew(val, addr + (where & 2));
	else if (size == 1)
		writeb(val, addr + (where & 3));
	else
		return PCIBIOS_BAD_REGISTER_NUMBER;

	return PCIBIOS_SUCCESSFUL;
}

static inline void dw_pcie_readl_rc(struct pcie_port *pp, u32 reg, u32 *val)
{
	if (pp->ops->readl_rc)
		pp->ops->readl_rc(pp, pp->dbi_base + reg, val);
	else
		*val = readl(pp->dbi_base + reg);
}

static inline void dw_pcie_writel_rc(struct pcie_port *pp, u32 val, u32 reg)
{
	if (pp->ops->writel_rc)
		pp->ops->writel_rc(pp, val, pp->dbi_base + reg);
	else
		writel(val, pp->dbi_base + reg);
}

#include <abort.h>

static int dw_pcie_rd_own_conf(struct pcie_port *pp, int where, int size,
			       u32 *val)
{
	int ret;

	if (pp->ops->rd_own_conf)
		ret = pp->ops->rd_own_conf(pp, where, size, val);
	else
		ret = dw_pcie_cfg_read(pp->dbi_base + (where & ~0x3), where,
				size, val);

	return ret;
}

static int dw_pcie_wr_own_conf(struct pcie_port *pp, int where, int size,
			       u32 val)
{
	int ret;

	if (pp->ops->wr_own_conf)
		ret = pp->ops->wr_own_conf(pp, where, size, val);
	else
		ret = dw_pcie_cfg_write(pp->dbi_base + (where & ~0x3), where,
				size, val);

	return ret;
}

int dw_pcie_link_up(struct pcie_port *pp)
{
	if (pp->ops->link_up)
		return pp->ops->link_up(pp);
	else
		return 0;
}

static inline struct pcie_port *host_to_pcie(struct pci_controller *host)
{
	return container_of(host, struct pcie_port, pci);
}

static void dw_pcie_set_local_bus_nr(struct pci_controller *host, int busno)
{
	struct pcie_port *pp = host_to_pcie(host);

	pp->root_bus_nr = busno;
}

static struct pci_ops dw_pcie_ops;

int __init dw_pcie_host_init(struct pcie_port *pp)
{
	struct device_node *np = pp->dev->device_node;
	struct of_pci_range range;
	struct of_pci_range_parser parser;
	struct resource *cfg_res;
	u32 val, na, ns;
	const __be32 *addrp;
	int index;

	/* Find the address cell size and the number of cells in order to get
	 * the untranslated address.
	 */
	of_property_read_u32(np, "#address-cells", &na);
	ns = of_n_size_cells(np);

	cfg_res = dev_get_resource_by_name(pp->dev, IORESOURCE_MEM, "config");
	if (cfg_res) {
		pp->cfg0_size = resource_size(cfg_res)/2;
		pp->cfg1_size = resource_size(cfg_res)/2;
		pp->cfg0_base = cfg_res->start;
		pp->cfg1_base = cfg_res->start + pp->cfg0_size;

		/* Find the untranslated configuration space address */
		index = of_property_match_string(np, "reg-names", "config");
		addrp = of_get_address(np, index, NULL, NULL);
		pp->cfg0_mod_base = of_read_number(addrp, ns);
		pp->cfg1_mod_base = pp->cfg0_mod_base + pp->cfg0_size;
	} else {
		dev_err(pp->dev, "missing *config* reg space\n");
	}

	if (of_pci_range_parser_init(&parser, np)) {
		dev_err(pp->dev, "missing ranges property\n");
		return -EINVAL;
	}

	/* Get the I/O and memory ranges from DT */
	for_each_of_pci_range(&parser, &range) {
		unsigned long restype = range.flags & IORESOURCE_TYPE_BITS;

		if (restype == IORESOURCE_IO) {
			of_pci_range_to_resource(&range, np, &pp->io);
			pp->io.name = "I/O";
			pp->io.start = range.pci_addr + global_io_offset;
			pp->io.end =  range.pci_addr + range.size + global_io_offset - 1;
			pp->io_size = resource_size(&pp->io);
			pp->io_bus_addr = range.pci_addr;
			pp->io_base = range.cpu_addr;

			/* Find the untranslated IO space address */
			pp->io_mod_base = of_read_number(parser.range -
							 parser.np + na, ns);
		}
		if (restype == IORESOURCE_MEM) {
			of_pci_range_to_resource(&range, np, &pp->mem);
			pp->mem.name = "MEM";
			pp->mem_size = resource_size(&pp->mem);
			pp->mem_bus_addr = range.pci_addr;

			/* Find the untranslated MEM space address */
			pp->mem_mod_base = of_read_number(parser.range -
							  parser.np + na, ns);
		}
		if (restype == 0) {
			of_pci_range_to_resource(&range, np, &pp->cfg);
			pp->cfg0_size = resource_size(&pp->cfg)/2;
			pp->cfg1_size = resource_size(&pp->cfg)/2;
			pp->cfg0_base = pp->cfg.start;
			pp->cfg1_base = pp->cfg.start + pp->cfg0_size;

			/* Find the untranslated configuration space address */
			pp->cfg0_mod_base = of_read_number(parser.range -
							   parser.np + na, ns);
			pp->cfg1_mod_base = pp->cfg0_mod_base +
					    pp->cfg0_size;
		}
	}

	if (!pp->dbi_base)
		pp->dbi_base = (void __force *)pp->cfg.start;

	pp->mem_base = pp->mem.start;

	if (!pp->va_cfg0_base)
		pp->va_cfg0_base = (void __force *)(u32)pp->cfg0_base;

	if (!pp->va_cfg1_base)
		pp->va_cfg1_base = (void __force *)(u32)pp->cfg1_base;

	if (of_property_read_u32(np, "num-lanes", &pp->lanes)) {
		dev_err(pp->dev, "Failed to parse the number of lanes\n");
		return -EINVAL;
	}

	if (pp->ops->host_init)
		pp->ops->host_init(pp);

	dw_pcie_wr_own_conf(pp, PCI_BASE_ADDRESS_0, 4, 0);

	/* program correct class for RC */
	dw_pcie_wr_own_conf(pp, PCI_CLASS_DEVICE, 2, PCI_CLASS_BRIDGE_PCI);

	dw_pcie_rd_own_conf(pp, PCIE_LINK_WIDTH_SPEED_CONTROL, 4, &val);
	val |= PORT_LOGIC_SPEED_CHANGE;
	dw_pcie_wr_own_conf(pp, PCIE_LINK_WIDTH_SPEED_CONTROL, 4, val);

	pp->pci.parent = pp->dev;
	pp->pci.pci_ops = &dw_pcie_ops;
	pp->pci.set_busno = dw_pcie_set_local_bus_nr;
	pp->pci.mem_resource = &pp->mem;
	pp->pci.io_resource = &pp->io;

	register_pci_controller(&pp->pci);

	return 0;
}

static void dw_pcie_prog_viewport_cfg0(struct pcie_port *pp, u32 busdev)
{
	/* Program viewport 0 : OUTBOUND : CFG0 */
	dw_pcie_writel_rc(pp, PCIE_ATU_REGION_OUTBOUND | PCIE_ATU_REGION_INDEX0,
			  PCIE_ATU_VIEWPORT);
	dw_pcie_writel_rc(pp, pp->cfg0_mod_base, PCIE_ATU_LOWER_BASE);
	dw_pcie_writel_rc(pp, (pp->cfg0_mod_base >> 32), PCIE_ATU_UPPER_BASE);
	dw_pcie_writel_rc(pp, pp->cfg0_mod_base + pp->cfg0_size - 1,
			  PCIE_ATU_LIMIT);
	dw_pcie_writel_rc(pp, busdev, PCIE_ATU_LOWER_TARGET);
	dw_pcie_writel_rc(pp, 0, PCIE_ATU_UPPER_TARGET);
	dw_pcie_writel_rc(pp, PCIE_ATU_TYPE_CFG0, PCIE_ATU_CR1);
	dw_pcie_writel_rc(pp, PCIE_ATU_ENABLE, PCIE_ATU_CR2);
}

static void dw_pcie_prog_viewport_cfg1(struct pcie_port *pp, u32 busdev)
{
	/* Program viewport 1 : OUTBOUND : CFG1 */
	dw_pcie_writel_rc(pp, PCIE_ATU_REGION_OUTBOUND | PCIE_ATU_REGION_INDEX1,
			  PCIE_ATU_VIEWPORT);
	dw_pcie_writel_rc(pp, PCIE_ATU_TYPE_CFG1, PCIE_ATU_CR1);
	dw_pcie_writel_rc(pp, pp->cfg1_mod_base, PCIE_ATU_LOWER_BASE);
	dw_pcie_writel_rc(pp, (pp->cfg1_mod_base >> 32), PCIE_ATU_UPPER_BASE);
	dw_pcie_writel_rc(pp, pp->cfg1_mod_base + pp->cfg1_size - 1,
			  PCIE_ATU_LIMIT);
	dw_pcie_writel_rc(pp, busdev, PCIE_ATU_LOWER_TARGET);
	dw_pcie_writel_rc(pp, 0, PCIE_ATU_UPPER_TARGET);
	dw_pcie_writel_rc(pp, PCIE_ATU_ENABLE, PCIE_ATU_CR2);
}

static void dw_pcie_prog_viewport_mem_outbound(struct pcie_port *pp)
{
	/* Program viewport 0 : OUTBOUND : MEM */
	dw_pcie_writel_rc(pp, PCIE_ATU_REGION_OUTBOUND | PCIE_ATU_REGION_INDEX0,
			  PCIE_ATU_VIEWPORT);
	dw_pcie_writel_rc(pp, PCIE_ATU_TYPE_MEM, PCIE_ATU_CR1);
	dw_pcie_writel_rc(pp, pp->mem_mod_base, PCIE_ATU_LOWER_BASE);
	dw_pcie_writel_rc(pp, (pp->mem_mod_base >> 32), PCIE_ATU_UPPER_BASE);
	dw_pcie_writel_rc(pp, pp->mem_mod_base + pp->mem_size - 1,
			  PCIE_ATU_LIMIT);
	dw_pcie_writel_rc(pp, pp->mem_bus_addr, PCIE_ATU_LOWER_TARGET);
	dw_pcie_writel_rc(pp, upper_32_bits(pp->mem_bus_addr),
			  PCIE_ATU_UPPER_TARGET);
	dw_pcie_writel_rc(pp, PCIE_ATU_ENABLE, PCIE_ATU_CR2);
}

static void dw_pcie_prog_viewport_io_outbound(struct pcie_port *pp)
{
	/* Program viewport 1 : OUTBOUND : IO */
	dw_pcie_writel_rc(pp, PCIE_ATU_REGION_OUTBOUND | PCIE_ATU_REGION_INDEX1,
			  PCIE_ATU_VIEWPORT);
	dw_pcie_writel_rc(pp, PCIE_ATU_TYPE_IO, PCIE_ATU_CR1);
	dw_pcie_writel_rc(pp, pp->io_mod_base, PCIE_ATU_LOWER_BASE);
	dw_pcie_writel_rc(pp, (pp->io_mod_base >> 32), PCIE_ATU_UPPER_BASE);
	dw_pcie_writel_rc(pp, pp->io_mod_base + pp->io_size - 1,
			  PCIE_ATU_LIMIT);
	dw_pcie_writel_rc(pp, pp->io_bus_addr, PCIE_ATU_LOWER_TARGET);
	dw_pcie_writel_rc(pp, upper_32_bits(pp->io_bus_addr),
			  PCIE_ATU_UPPER_TARGET);
	dw_pcie_writel_rc(pp, PCIE_ATU_ENABLE, PCIE_ATU_CR2);
}

struct pci_bus *get_parent_bus(struct pci_bus *bus)
{
	struct pci_dev *bridge = container_of(bus->parent, struct pci_dev, dev);

	return bridge->bus;
}

static int dw_pcie_rd_other_conf(struct pcie_port *pp, struct pci_bus *bus,
		u32 devfn, int where, int size, u32 *val)
{
	int ret = PCIBIOS_SUCCESSFUL;
	u32 address, busdev;

	busdev = PCIE_ATU_BUS(bus->number) | PCIE_ATU_DEV(PCI_SLOT(devfn)) |
		 PCIE_ATU_FUNC(PCI_FUNC(devfn));
	address = where & ~0x3;

	if (get_parent_bus(bus)->number == pp->root_bus_nr) {
		dw_pcie_prog_viewport_cfg0(pp, busdev);
		ret = dw_pcie_cfg_read(pp->va_cfg0_base + address, where, size,
				val);
		dw_pcie_prog_viewport_mem_outbound(pp);
	} else {
		dw_pcie_prog_viewport_cfg1(pp, busdev);
		ret = dw_pcie_cfg_read(pp->va_cfg1_base + address, where, size,
				val);
		dw_pcie_prog_viewport_io_outbound(pp);
	}

	return ret;
}

static int dw_pcie_wr_other_conf(struct pcie_port *pp, struct pci_bus *bus,
		u32 devfn, int where, int size, u32 val)
{
	int ret = PCIBIOS_SUCCESSFUL;
	u32 address, busdev;

	busdev = PCIE_ATU_BUS(bus->number) | PCIE_ATU_DEV(PCI_SLOT(devfn)) |
		 PCIE_ATU_FUNC(PCI_FUNC(devfn));
	address = where & ~0x3;

	if (get_parent_bus(bus)->number == pp->root_bus_nr) {
		dw_pcie_prog_viewport_cfg0(pp, busdev);
		ret = dw_pcie_cfg_write(pp->va_cfg0_base + address, where, size,
				val);
		dw_pcie_prog_viewport_mem_outbound(pp);
	} else {
		dw_pcie_prog_viewport_cfg1(pp, busdev);
		ret = dw_pcie_cfg_write(pp->va_cfg1_base + address, where, size,
				val);
		dw_pcie_prog_viewport_io_outbound(pp);
	}

	return ret;
}

static int dw_pcie_valid_config(struct pcie_port *pp,
				struct pci_bus *bus, int dev)
{
	/* If there is no link, then there is no device */
	if (bus->number != pp->root_bus_nr) {
		if (!dw_pcie_link_up(pp))
			return 0;
	}

	/* access only one slot on each root port */
	if (bus->number == pp->root_bus_nr && dev > 0)
		return 0;

	/*
	 * do not read more than one device on the bus directly attached
	 * to RC's (Virtual Bridge's) DS side.
	 */
	if (bus->primary == pp->root_bus_nr && dev > 0)
		return 0;

	return 1;
}

static int dw_pcie_rd_conf(struct pci_bus *bus, u32 devfn, int where,
			int size, u32 *val)
{
	struct pcie_port *pp = host_to_pcie(bus->host);
	int ret;

	*val = 0xffffffff;

	if (dw_pcie_valid_config(pp, bus, PCI_SLOT(devfn)) == 0)
		return PCIBIOS_DEVICE_NOT_FOUND;

	data_abort_mask();

	if (bus->number != pp->root_bus_nr)
		if (pp->ops->rd_other_conf)
			ret = pp->ops->rd_other_conf(pp, bus, devfn,
						where, size, val);
		else
			ret = dw_pcie_rd_other_conf(pp, bus, devfn,
						where, size, val);
	else
		ret = dw_pcie_rd_own_conf(pp, where, size, val);

	if (data_abort_unmask())
		return PCIBIOS_DEVICE_NOT_FOUND;

	return ret;
}

static int dw_pcie_wr_conf(struct pci_bus *bus, u32 devfn,
			int where, int size, u32 val)
{
	struct pcie_port *pp = host_to_pcie(bus->host);
	int ret;

	if (dw_pcie_valid_config(pp, bus, PCI_SLOT(devfn)) == 0)
		return PCIBIOS_DEVICE_NOT_FOUND;

	data_abort_mask();

	if (bus->number != pp->root_bus_nr)
		if (pp->ops->wr_other_conf)
			ret = pp->ops->wr_other_conf(pp, bus, devfn,
						where, size, val);
		else
			ret = dw_pcie_wr_other_conf(pp, bus, devfn,
						where, size, val);
	else
		ret = dw_pcie_wr_own_conf(pp, where, size, val);

	if (data_abort_unmask())
		return PCIBIOS_DEVICE_NOT_FOUND;

	return ret;
}

static int dw_pcie_res_start(struct pci_bus *bus, resource_size_t res_addr)
{
	return res_addr;
}

static struct pci_ops dw_pcie_ops = {
	.read = dw_pcie_rd_conf,
	.write = dw_pcie_wr_conf,
	.res_start = dw_pcie_res_start,
};

void dw_pcie_setup_rc(struct pcie_port *pp)
{
	u32 val;
	u32 membase;
	u32 memlimit;

	/* set the number of lanes */
	dw_pcie_readl_rc(pp, PCIE_PORT_LINK_CONTROL, &val);
	val &= ~PORT_LINK_MODE_MASK;
	switch (pp->lanes) {
	case 1:
		val |= PORT_LINK_MODE_1_LANES;
		break;
	case 2:
		val |= PORT_LINK_MODE_2_LANES;
		break;
	case 4:
		val |= PORT_LINK_MODE_4_LANES;
		break;
	}
	dw_pcie_writel_rc(pp, val, PCIE_PORT_LINK_CONTROL);

	/* set link width speed control register */
	dw_pcie_readl_rc(pp, PCIE_LINK_WIDTH_SPEED_CONTROL, &val);
	val &= ~PORT_LOGIC_LINK_WIDTH_MASK;
	switch (pp->lanes) {
	case 1:
		val |= PORT_LOGIC_LINK_WIDTH_1_LANES;
		break;
	case 2:
		val |= PORT_LOGIC_LINK_WIDTH_2_LANES;
		break;
	case 4:
		val |= PORT_LOGIC_LINK_WIDTH_4_LANES;
		break;
	}
	dw_pcie_writel_rc(pp, val, PCIE_LINK_WIDTH_SPEED_CONTROL);

	/* setup RC BARs */
	dw_pcie_writel_rc(pp, 0x00000004, PCI_BASE_ADDRESS_0);
	dw_pcie_writel_rc(pp, 0x00000000, PCI_BASE_ADDRESS_1);

	/* setup bus numbers */
	dw_pcie_readl_rc(pp, PCI_PRIMARY_BUS, &val);
	val &= 0xff000000;
	val |= 0x00010100;
	dw_pcie_writel_rc(pp, val, PCI_PRIMARY_BUS);

	/* setup memory base, memory limit */
	membase = ((u32)pp->mem_base & 0xfff00000) >> 16;
	memlimit = (pp->mem_size + (u32)pp->mem_base) & 0xfff00000;
	val = memlimit | membase;
	dw_pcie_writel_rc(pp, val, PCI_MEMORY_BASE);

	/* setup command register */
	dw_pcie_readl_rc(pp, PCI_COMMAND, &val);
	val &= 0xffff0000;
	val |= PCI_COMMAND_IO | PCI_COMMAND_MEMORY |
		PCI_COMMAND_MASTER | PCI_COMMAND_SERR;
	dw_pcie_writel_rc(pp, val, PCI_COMMAND);
}

MODULE_AUTHOR("Jingoo Han <jg1.han@samsung.com>");
MODULE_DESCRIPTION("Designware PCIe host controller driver");
MODULE_LICENSE("GPL v2");