// SPDX-License-Identifier: GPL-2.0+
/*
* BRIEF MODULE DESCRIPTION
* PCI init for Ralink RT2880 solution
*
* Copyright 2007 Ralink Inc. ([email protected])
*
* May 2007 Bruce Chang
* Initial Release
*
* May 2009 Bruce Chang
* support RT2880/RT3883 PCIe
*
* May 2011 Bruce Chang
* support RT6855/MT7620 PCIe
*/
#include <linux/bitops.h>
#include <linux/clk.h>
#include <linux/delay.h>
#include <linux/gpio/consumer.h>
#include <linux/module.h>
#include <linux/of.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/reset.h>
#include <linux/sys_soc.h>
#include "../pci.h"
/* 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)
/* Host-PCI bridge registers */
#define RALINK_PCI_PCICFG_ADDR 0x0000
#define RALINK_PCI_PCIMSK_ADDR 0x000c
#define RALINK_PCI_CONFIG_ADDR 0x0020
#define RALINK_PCI_CONFIG_DATA 0x0024
#define RALINK_PCI_MEMBASE 0x0028
#define RALINK_PCI_IOBASE 0x002c
/* PCIe RC control registers */
#define RALINK_PCI_ID 0x0030
#define RALINK_PCI_CLASS 0x0034
#define RALINK_PCI_SUBID 0x0038
#define RALINK_PCI_STATUS 0x0050
/* Some definition values */
#define PCIE_REVISION_ID BIT(0)
#define PCIE_CLASS_CODE (0x60400 << 8)
#define PCIE_BAR_MAP_MAX GENMASK(30, 16)
#define PCIE_BAR_ENABLE BIT(0)
#define PCIE_PORT_INT_EN(x) BIT(20 + (x))
#define PCIE_PORT_LINKUP BIT(0)
#define PCIE_PORT_CNT 3
#define INIT_PORTS_DELAY_MS 100
#define PERST_DELAY_MS 100
/**
* struct mt7621_pcie_port - PCIe port information
* @base: I/O mapped register base
* @list: port list
* @pcie: pointer to PCIe host info
* @clk: pointer to the port clock gate
* @phy: pointer to PHY control block
* @pcie_rst: pointer to port reset control
* @gpio_rst: gpio reset
* @slot: port slot
* @enabled: indicates if port is enabled
*/
struct mt7621_pcie_port {
void __iomem *base;
struct list_head list;
struct mt7621_pcie *pcie;
struct clk *clk;
struct phy *phy;
struct reset_control *pcie_rst;
struct gpio_desc *gpio_rst;
u32 slot;
bool enabled;
};
/**
* struct mt7621_pcie - PCIe host information
* @base: IO Mapped Register Base
* @dev: Pointer to PCIe device
* @ports: pointer to PCIe port information
* @resets_inverted: depends on chip revision
* reset lines are inverted.
*/
struct mt7621_pcie {
struct device *dev;
void __iomem *base;
struct list_head ports;
bool resets_inverted;
};
static inline u32 pcie_read(struct mt7621_pcie *pcie, u32 reg)
{
return readl_relaxed(pcie->base + reg);
}
static inline void pcie_write(struct mt7621_pcie *pcie, u32 val, u32 reg)
{
writel_relaxed(val, pcie->base + reg);
}
static inline u32 pcie_port_read(struct mt7621_pcie_port *port, u32 reg)
{
return readl_relaxed(port->base + reg);
}
static inline void pcie_port_write(struct mt7621_pcie_port *port,
u32 val, u32 reg)
{
writel_relaxed(val, port->base + reg);
}
static void __iomem *mt7621_pcie_map_bus(struct pci_bus *bus,
unsigned int devfn, int where)
{
struct mt7621_pcie *pcie = bus->sysdata;
u32 address = PCI_CONF1_EXT_ADDRESS(bus->number, PCI_SLOT(devfn),
PCI_FUNC(devfn), where);
writel_relaxed(address, pcie->base + RALINK_PCI_CONFIG_ADDR);
return pcie->base + RALINK_PCI_CONFIG_DATA + (where & 3);
}
static struct pci_ops mt7621_pcie_ops = {
.map_bus = mt7621_pcie_map_bus,
.read = pci_generic_config_read,
.write = pci_generic_config_write,
};
static u32 read_config(struct mt7621_pcie *pcie, unsigned int dev, u32 reg)
{
u32 address = PCI_CONF1_EXT_ADDRESS(0, dev, 0, reg);
pcie_write(pcie, address, RALINK_PCI_CONFIG_ADDR);
return pcie_read(pcie, RALINK_PCI_CONFIG_DATA);
}
static void write_config(struct mt7621_pcie *pcie, unsigned int dev,
u32 reg, u32 val)
{
u32 address = PCI_CONF1_EXT_ADDRESS(0, dev, 0, reg);
pcie_write(pcie, address, RALINK_PCI_CONFIG_ADDR);
pcie_write(pcie, val, RALINK_PCI_CONFIG_DATA);
}
static inline void mt7621_rst_gpio_pcie_assert(struct mt7621_pcie_port *port)
{
if (port->gpio_rst)
gpiod_set_value(port->gpio_rst, 1);
}
static inline void mt7621_rst_gpio_pcie_deassert(struct mt7621_pcie_port *port)
{
if (port->gpio_rst)
gpiod_set_value(port->gpio_rst, 0);
}
static inline bool mt7621_pcie_port_is_linkup(struct mt7621_pcie_port *port)
{
return (pcie_port_read(port, RALINK_PCI_STATUS) & PCIE_PORT_LINKUP) != 0;
}
static inline void mt7621_control_assert(struct mt7621_pcie_port *port)
{
struct mt7621_pcie *pcie = port->pcie;
if (pcie->resets_inverted)
reset_control_assert(port->pcie_rst);
else
reset_control_deassert(port->pcie_rst);
}
static inline void mt7621_control_deassert(struct mt7621_pcie_port *port)
{
struct mt7621_pcie *pcie = port->pcie;
if (pcie->resets_inverted)
reset_control_deassert(port->pcie_rst);
else
reset_control_assert(port->pcie_rst);
}
static int mt7621_pcie_parse_port(struct mt7621_pcie *pcie,
struct device_node *node,
int slot)
{
struct mt7621_pcie_port *port;
struct device *dev = pcie->dev;
struct platform_device *pdev = to_platform_device(dev);
char name[11];
int err;
port = devm_kzalloc(dev, sizeof(*port), GFP_KERNEL);
if (!port)
return -ENOMEM;
port->base = devm_platform_ioremap_resource(pdev, slot + 1);
if (IS_ERR(port->base))
return PTR_ERR(port->base);
port->clk = devm_get_clk_from_child(dev, node, NULL);
if (IS_ERR(port->clk)) {
dev_err(dev, "failed to get pcie%d clock\n", slot);
return PTR_ERR(port->clk);
}
port->pcie_rst = of_reset_control_get_exclusive(node, NULL);
if (PTR_ERR(port->pcie_rst) == -EPROBE_DEFER) {
dev_err(dev, "failed to get pcie%d reset control\n", slot);
return PTR_ERR(port->pcie_rst);
}
snprintf(name, sizeof(name), "pcie-phy%d", slot);
port->phy = devm_of_phy_get(dev, node, name);
if (IS_ERR(port->phy)) {
dev_err(dev, "failed to get pcie-phy%d\n", slot);
err = PTR_ERR(port->phy);
goto remove_reset;
}
port->gpio_rst = devm_gpiod_get_index_optional(dev, "reset", slot,
GPIOD_OUT_LOW);
if (IS_ERR(port->gpio_rst)) {
dev_err(dev, "failed to get GPIO for PCIe%d\n", slot);
err = PTR_ERR(port->gpio_rst);
goto remove_reset;
}
port->slot = slot;
port->pcie = pcie;
INIT_LIST_HEAD(&port->list);
list_add_tail(&port->list, &pcie->ports);
return 0;
remove_reset:
reset_control_put(port->pcie_rst);
return err;
}
static int mt7621_pcie_parse_dt(struct mt7621_pcie *pcie)
{
struct device *dev = pcie->dev;
struct platform_device *pdev = to_platform_device(dev);
struct device_node *node = dev->of_node, *child;
int err;
pcie->base = devm_platform_ioremap_resource(pdev, 0);
if (IS_ERR(pcie->base))
return PTR_ERR(pcie->base);
for_each_available_child_of_node(node, child) {
int slot;
err = of_pci_get_devfn(child);
if (err < 0) {
of_node_put(child);
dev_err(dev, "failed to parse devfn: %d\n", err);
return err;
}
slot = PCI_SLOT(err);
err = mt7621_pcie_parse_port(pcie, child, slot);
if (err) {
of_node_put(child);
return err;
}
}
return 0;
}
static int mt7621_pcie_init_port(struct mt7621_pcie_port *port)
{
struct mt7621_pcie *pcie = port->pcie;
struct device *dev = pcie->dev;
u32 slot = port->slot;
int err;
err = phy_init(port->phy);
if (err) {
dev_err(dev, "failed to initialize port%d phy\n", slot);
return err;
}
err = phy_power_on(port->phy);
if (err) {
dev_err(dev, "failed to power on port%d phy\n", slot);
phy_exit(port->phy);
return err;
}
port->enabled = true;
return 0;
}
static void mt7621_pcie_reset_assert(struct mt7621_pcie *pcie)
{
struct mt7621_pcie_port *port;
list_for_each_entry(port, &pcie->ports, list) {
/* PCIe RC reset assert */
mt7621_control_assert(port);
/* PCIe EP reset assert */
mt7621_rst_gpio_pcie_assert(port);
}
msleep(PERST_DELAY_MS);
}
static void mt7621_pcie_reset_rc_deassert(struct mt7621_pcie *pcie)
{
struct mt7621_pcie_port *port;
list_for_each_entry(port, &pcie->ports, list)
mt7621_control_deassert(port);
}
static void mt7621_pcie_reset_ep_deassert(struct mt7621_pcie *pcie)
{
struct mt7621_pcie_port *port;
list_for_each_entry(port, &pcie->ports, list)
mt7621_rst_gpio_pcie_deassert(port);
msleep(PERST_DELAY_MS);
}
static int mt7621_pcie_init_ports(struct mt7621_pcie *pcie)
{
struct device *dev = pcie->dev;
struct mt7621_pcie_port *port, *tmp;
u8 num_disabled = 0;
int err;
mt7621_pcie_reset_assert(pcie);
mt7621_pcie_reset_rc_deassert(pcie);
list_for_each_entry_safe(port, tmp, &pcie->ports, list) {
u32 slot = port->slot;
if (slot == 1) {
port->enabled = true;
continue;
}
err = mt7621_pcie_init_port(port);
if (err) {
dev_err(dev, "initializing port %d failed\n", slot);
list_del(&port->list);
}
}
msleep(INIT_PORTS_DELAY_MS);
mt7621_pcie_reset_ep_deassert(pcie);
tmp = NULL;
list_for_each_entry(port, &pcie->ports, list) {
u32 slot = port->slot;
if (!mt7621_pcie_port_is_linkup(port)) {
dev_info(dev, "pcie%d no card, disable it (RST & CLK)\n",
slot);
mt7621_control_assert(port);
port->enabled = false;
num_disabled++;
if (slot == 0) {
tmp = port;
continue;
}
if (slot == 1 && tmp && !tmp->enabled)
phy_power_off(tmp->phy);
}
}
return (num_disabled != PCIE_PORT_CNT) ? 0 : -ENODEV;
}
static void mt7621_pcie_enable_port(struct mt7621_pcie_port *port)
{
struct mt7621_pcie *pcie = port->pcie;
u32 slot = port->slot;
u32 val;
/* enable pcie interrupt */
val = pcie_read(pcie, RALINK_PCI_PCIMSK_ADDR);
val |= PCIE_PORT_INT_EN(slot);
pcie_write(pcie, val, RALINK_PCI_PCIMSK_ADDR);
/* map 2G DDR region */
pcie_port_write(port, PCIE_BAR_MAP_MAX | PCIE_BAR_ENABLE,
PCI_BASE_ADDRESS_0);
/* configure class code and revision ID */
pcie_port_write(port, PCIE_CLASS_CODE | PCIE_REVISION_ID,
RALINK_PCI_CLASS);
/* configure RC FTS number to 250 when it leaves L0s */
val = read_config(pcie, slot, PCIE_FTS_NUM);
val &= ~PCIE_FTS_NUM_MASK;
val |= PCIE_FTS_NUM_L0(0x50);
write_config(pcie, slot, PCIE_FTS_NUM, val);
}
static int mt7621_pcie_enable_ports(struct pci_host_bridge *host)
{
struct mt7621_pcie *pcie = pci_host_bridge_priv(host);
struct device *dev = pcie->dev;
struct mt7621_pcie_port *port;
struct resource_entry *entry;
int err;
entry = resource_list_first_type(&host->windows, IORESOURCE_IO);
if (!entry) {
dev_err(dev, "cannot get io resource\n");
return -EINVAL;
}
/* Setup MEMWIN and IOWIN */
pcie_write(pcie, 0xffffffff, RALINK_PCI_MEMBASE);
pcie_write(pcie, entry->res->start - entry->offset, RALINK_PCI_IOBASE);
list_for_each_entry(port, &pcie->ports, list) {
if (port->enabled) {
err = clk_prepare_enable(port->clk);
if (err) {
dev_err(dev, "enabling clk pcie%d\n",
port->slot);
return err;
}
mt7621_pcie_enable_port(port);
dev_info(dev, "PCIE%d enabled\n", port->slot);
}
}
return 0;
}
static int mt7621_pcie_register_host(struct pci_host_bridge *host)
{
struct mt7621_pcie *pcie = pci_host_bridge_priv(host);
host->ops = &mt7621_pcie_ops;
host->sysdata = pcie;
return pci_host_probe(host);
}
static const struct soc_device_attribute mt7621_pcie_quirks_match[] = {
{ .soc_id = "mt7621", .revision = "E2" },
{ /* sentinel */ }
};
static int mt7621_pcie_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
const struct soc_device_attribute *attr;
struct mt7621_pcie_port *port;
struct mt7621_pcie *pcie;
struct pci_host_bridge *bridge;
int err;
if (!dev->of_node)
return -ENODEV;
bridge = devm_pci_alloc_host_bridge(dev, sizeof(*pcie));
if (!bridge)
return -ENOMEM;
pcie = pci_host_bridge_priv(bridge);
pcie->dev = dev;
platform_set_drvdata(pdev, pcie);
INIT_LIST_HEAD(&pcie->ports);
attr = soc_device_match(mt7621_pcie_quirks_match);
if (attr)
pcie->resets_inverted = true;
err = mt7621_pcie_parse_dt(pcie);
if (err) {
dev_err(dev, "parsing DT failed\n");
return err;
}
err = mt7621_pcie_init_ports(pcie);
if (err) {
dev_err(dev, "nothing connected in virtual bridges\n");
return 0;
}
err = mt7621_pcie_enable_ports(bridge);
if (err) {
dev_err(dev, "error enabling pcie ports\n");
goto remove_resets;
}
return mt7621_pcie_register_host(bridge);
remove_resets:
list_for_each_entry(port, &pcie->ports, list)
reset_control_put(port->pcie_rst);
return err;
}
static void mt7621_pcie_remove(struct platform_device *pdev)
{
struct mt7621_pcie *pcie = platform_get_drvdata(pdev);
struct mt7621_pcie_port *port;
list_for_each_entry(port, &pcie->ports, list)
reset_control_put(port->pcie_rst);
}
static const struct of_device_id mt7621_pcie_ids[] = {
{ .compatible = "mediatek,mt7621-pci" },
{},
};
MODULE_DEVICE_TABLE(of, mt7621_pcie_ids);
static struct platform_driver mt7621_pcie_driver = {
.probe = mt7621_pcie_probe,
.remove_new = mt7621_pcie_remove,
.driver = {
.name = "mt7621-pci",
.of_match_table = mt7621_pcie_ids,
},
};
builtin_platform_driver(mt7621_pcie_driver);
MODULE_DESCRIPTION("MediaTek MT7621 PCIe host controller driver");
MODULE_LICENSE("GPL v2");
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