swh:1:snp:c3bf2749e3476071fa748f67b0ffa2fdc5fe49d9
Tip revision: 569dbb88e80deb68974ef6fdd6a13edb9d686261 authored by Linus Torvalds on 03 September 2017, 20:56:17 UTC
Linux 4.13
Linux 4.13
Tip revision: 569dbb8
pcie-mediatek.c
/*
* MediaTek PCIe host controller driver.
*
* Copyright (c) 2017 MediaTek Inc.
* Author: Ryder Lee <ryder.lee@mediatek.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.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/
#include <linux/clk.h>
#include <linux/delay.h>
#include <linux/kernel.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>
/* 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)
/**
* 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 bus clock
* @phy: pointer to phy control block
* @lane: lane count
* @index: port index
*/
struct mtk_pcie_port {
void __iomem *base;
struct list_head list;
struct mtk_pcie *pcie;
struct reset_control *reset;
struct clk *sys_ck;
struct phy *phy;
u32 lane;
u32 index;
};
/**
* 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
*/
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;
};
static inline bool mtk_pcie_link_up(struct mtk_pcie_port *port)
{
return !!(readl(port->base + PCIE_LINK_STATUS) & PCIE_PORT_LINKUP);
}
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);
clk_disable_unprepare(port->sys_ck);
mtk_pcie_port_free(port);
}
mtk_pcie_subsys_powerdown(pcie);
}
static void __iomem *mtk_pcie_map_bus(struct pci_bus *bus,
unsigned int devfn, int where)
{
struct pci_host_bridge *host = pci_find_host_bridge(bus);
struct mtk_pcie *pcie = pci_host_bridge_priv(host);
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 void mtk_pcie_configure_rc(struct mtk_pcie_port *port)
{
struct mtk_pcie *pcie = port->pcie;
u32 func = PCI_FUNC(port->index << 3);
u32 slot = PCI_SLOT(port->index << 3);
u32 val;
/* enable interrupt */
val = readl(pcie->base + PCIE_INT_ENABLE);
val |= PCIE_PORT_INT_EN(port->index);
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);
}
static void mtk_pcie_assert_ports(struct mtk_pcie_port *port)
{
struct mtk_pcie *pcie = port->pcie;
u32 val;
/* assert port PERST_N */
val = readl(pcie->base + PCIE_SYS_CFG);
val |= PCIE_PORT_PERST(port->index);
writel(val, pcie->base + PCIE_SYS_CFG);
/* de-assert port PERST_N */
val = readl(pcie->base + PCIE_SYS_CFG);
val &= ~PCIE_PORT_PERST(port->index);
writel(val, pcie->base + PCIE_SYS_CFG);
/* PCIe v2.0 need at least 100ms delay to train from Gen1 to Gen2 */
msleep(100);
}
static void mtk_pcie_enable_ports(struct mtk_pcie_port *port)
{
struct device *dev = port->pcie->dev;
int err;
err = clk_prepare_enable(port->sys_ck);
if (err) {
dev_err(dev, "failed to enable port%d clock\n", port->index);
goto err_sys_clk;
}
reset_control_assert(port->reset);
reset_control_deassert(port->reset);
err = phy_power_on(port->phy);
if (err) {
dev_err(dev, "failed to power on port%d phy\n", port->index);
goto err_phy_on;
}
mtk_pcie_assert_ports(port);
/* if link up, then setup root port configuration space */
if (mtk_pcie_link_up(port)) {
mtk_pcie_configure_rc(port);
return;
}
dev_info(dev, "Port%d link down\n", port->index);
phy_power_off(port->phy);
err_phy_on:
clk_disable_unprepare(port->sys_ck);
err_sys_clk:
mtk_pcie_port_free(port);
}
static int mtk_pcie_parse_ports(struct mtk_pcie *pcie,
struct device_node *node,
int index)
{
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;
}
regs = platform_get_resource(pdev, IORESOURCE_MEM, index + 1);
port->base = devm_ioremap_resource(dev, regs);
if (IS_ERR(port->base)) {
dev_err(dev, "failed to map port%d base\n", index);
return PTR_ERR(port->base);
}
snprintf(name, sizeof(name), "sys_ck%d", index);
port->sys_ck = devm_clk_get(dev, name);
if (IS_ERR(port->sys_ck)) {
dev_err(dev, "failed to get port%d clock\n", index);
return PTR_ERR(port->sys_ck);
}
snprintf(name, sizeof(name), "pcie-rst%d", index);
port->reset = devm_reset_control_get_optional(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", index);
port->phy = devm_phy_optional_get(dev, name);
if (IS_ERR(port->phy))
return PTR_ERR(port->phy);
port->index = index;
port->pcie = pcie;
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 */
regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
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 index;
err = of_pci_get_devfn(child);
if (err < 0) {
dev_err(dev, "failed to parse devfn: %d\n", err);
return err;
}
index = PCI_SLOT(err);
err = mtk_pcie_parse_ports(pcie, child, index);
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_ports(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;
pci_remap_iospace(&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 = &mtk_pcie_ops;
host->map_irq = of_irq_parse_and_map_pci;
host->swizzle_irq = pci_common_swizzle;
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;
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 of_device_id mtk_pcie_ids[] = {
{ .compatible = "mediatek,mt7623-pcie"},
{ .compatible = "mediatek,mt2701-pcie"},
{},
};
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);