527 lines
12 KiB
C
527 lines
12 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
|
|
/*
|
|
* ACPI Hardware Watchdog (WDAT) driver.
|
|
*
|
|
* Copyright (C) 2016, Intel Corporation
|
|
* Author: Mika Westerberg <mika.westerberg@linux.intel.com>
|
|
*/
|
|
|
|
#include <linux/acpi.h>
|
|
#include <linux/ioport.h>
|
|
#include <linux/module.h>
|
|
#include <linux/platform_device.h>
|
|
#include <linux/pm.h>
|
|
#include <linux/watchdog.h>
|
|
|
|
#define MAX_WDAT_ACTIONS ACPI_WDAT_ACTION_RESERVED
|
|
|
|
/**
|
|
* struct wdat_instruction - Single ACPI WDAT instruction
|
|
* @entry: Copy of the ACPI table instruction
|
|
* @reg: Register the instruction is accessing
|
|
* @node: Next instruction in action sequence
|
|
*/
|
|
struct wdat_instruction {
|
|
struct acpi_wdat_entry entry;
|
|
void __iomem *reg;
|
|
struct list_head node;
|
|
};
|
|
|
|
/**
|
|
* struct wdat_wdt - ACPI WDAT watchdog device
|
|
* @pdev: Parent platform device
|
|
* @wdd: Watchdog core device
|
|
* @period: How long is one watchdog period in ms
|
|
* @stopped_in_sleep: Is this watchdog stopped by the firmware in S1-S5
|
|
* @stopped: Was the watchdog stopped by the driver in suspend
|
|
* @actions: An array of instruction lists indexed by an action number from
|
|
* the WDAT table. There can be %NULL entries for not implemented
|
|
* actions.
|
|
*/
|
|
struct wdat_wdt {
|
|
struct platform_device *pdev;
|
|
struct watchdog_device wdd;
|
|
unsigned int period;
|
|
bool stopped_in_sleep;
|
|
bool stopped;
|
|
struct list_head *instructions[MAX_WDAT_ACTIONS];
|
|
};
|
|
|
|
#define to_wdat_wdt(wdd) container_of(wdd, struct wdat_wdt, wdd)
|
|
|
|
static bool nowayout = WATCHDOG_NOWAYOUT;
|
|
module_param(nowayout, bool, 0);
|
|
MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="
|
|
__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
|
|
|
|
static int wdat_wdt_read(struct wdat_wdt *wdat,
|
|
const struct wdat_instruction *instr, u32 *value)
|
|
{
|
|
const struct acpi_generic_address *gas = &instr->entry.register_region;
|
|
|
|
switch (gas->access_width) {
|
|
case 1:
|
|
*value = ioread8(instr->reg);
|
|
break;
|
|
case 2:
|
|
*value = ioread16(instr->reg);
|
|
break;
|
|
case 3:
|
|
*value = ioread32(instr->reg);
|
|
break;
|
|
default:
|
|
return -EINVAL;
|
|
}
|
|
|
|
dev_dbg(&wdat->pdev->dev, "Read %#x from 0x%08llx\n", *value,
|
|
gas->address);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int wdat_wdt_write(struct wdat_wdt *wdat,
|
|
const struct wdat_instruction *instr, u32 value)
|
|
{
|
|
const struct acpi_generic_address *gas = &instr->entry.register_region;
|
|
|
|
switch (gas->access_width) {
|
|
case 1:
|
|
iowrite8((u8)value, instr->reg);
|
|
break;
|
|
case 2:
|
|
iowrite16((u16)value, instr->reg);
|
|
break;
|
|
case 3:
|
|
iowrite32(value, instr->reg);
|
|
break;
|
|
default:
|
|
return -EINVAL;
|
|
}
|
|
|
|
dev_dbg(&wdat->pdev->dev, "Wrote %#x to 0x%08llx\n", value,
|
|
gas->address);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int wdat_wdt_run_action(struct wdat_wdt *wdat, unsigned int action,
|
|
u32 param, u32 *retval)
|
|
{
|
|
struct wdat_instruction *instr;
|
|
|
|
if (action >= ARRAY_SIZE(wdat->instructions))
|
|
return -EINVAL;
|
|
|
|
if (!wdat->instructions[action])
|
|
return -EOPNOTSUPP;
|
|
|
|
dev_dbg(&wdat->pdev->dev, "Running action %#x\n", action);
|
|
|
|
/* Run each instruction sequentially */
|
|
list_for_each_entry(instr, wdat->instructions[action], node) {
|
|
const struct acpi_wdat_entry *entry = &instr->entry;
|
|
const struct acpi_generic_address *gas;
|
|
u32 flags, value, mask, x, y;
|
|
bool preserve;
|
|
int ret;
|
|
|
|
gas = &entry->register_region;
|
|
|
|
preserve = entry->instruction & ACPI_WDAT_PRESERVE_REGISTER;
|
|
flags = entry->instruction & ~ACPI_WDAT_PRESERVE_REGISTER;
|
|
value = entry->value;
|
|
mask = entry->mask;
|
|
|
|
switch (flags) {
|
|
case ACPI_WDAT_READ_VALUE:
|
|
ret = wdat_wdt_read(wdat, instr, &x);
|
|
if (ret)
|
|
return ret;
|
|
x >>= gas->bit_offset;
|
|
x &= mask;
|
|
if (retval)
|
|
*retval = x == value;
|
|
break;
|
|
|
|
case ACPI_WDAT_READ_COUNTDOWN:
|
|
ret = wdat_wdt_read(wdat, instr, &x);
|
|
if (ret)
|
|
return ret;
|
|
x >>= gas->bit_offset;
|
|
x &= mask;
|
|
if (retval)
|
|
*retval = x;
|
|
break;
|
|
|
|
case ACPI_WDAT_WRITE_VALUE:
|
|
x = value & mask;
|
|
x <<= gas->bit_offset;
|
|
if (preserve) {
|
|
ret = wdat_wdt_read(wdat, instr, &y);
|
|
if (ret)
|
|
return ret;
|
|
y = y & ~(mask << gas->bit_offset);
|
|
x |= y;
|
|
}
|
|
ret = wdat_wdt_write(wdat, instr, x);
|
|
if (ret)
|
|
return ret;
|
|
break;
|
|
|
|
case ACPI_WDAT_WRITE_COUNTDOWN:
|
|
x = param;
|
|
x &= mask;
|
|
x <<= gas->bit_offset;
|
|
if (preserve) {
|
|
ret = wdat_wdt_read(wdat, instr, &y);
|
|
if (ret)
|
|
return ret;
|
|
y = y & ~(mask << gas->bit_offset);
|
|
x |= y;
|
|
}
|
|
ret = wdat_wdt_write(wdat, instr, x);
|
|
if (ret)
|
|
return ret;
|
|
break;
|
|
|
|
default:
|
|
dev_err(&wdat->pdev->dev, "Unknown instruction: %u\n",
|
|
flags);
|
|
return -EINVAL;
|
|
}
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int wdat_wdt_enable_reboot(struct wdat_wdt *wdat)
|
|
{
|
|
int ret;
|
|
|
|
/*
|
|
* WDAT specification says that the watchdog is required to reboot
|
|
* the system when it fires. However, it also states that it is
|
|
* recommeded to make it configurable through hardware register. We
|
|
* enable reboot now if it is configrable, just in case.
|
|
*/
|
|
ret = wdat_wdt_run_action(wdat, ACPI_WDAT_SET_REBOOT, 0, NULL);
|
|
if (ret && ret != -EOPNOTSUPP) {
|
|
dev_err(&wdat->pdev->dev,
|
|
"Failed to enable reboot when watchdog triggers\n");
|
|
return ret;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void wdat_wdt_boot_status(struct wdat_wdt *wdat)
|
|
{
|
|
u32 boot_status = 0;
|
|
int ret;
|
|
|
|
ret = wdat_wdt_run_action(wdat, ACPI_WDAT_GET_STATUS, 0, &boot_status);
|
|
if (ret && ret != -EOPNOTSUPP) {
|
|
dev_err(&wdat->pdev->dev, "Failed to read boot status\n");
|
|
return;
|
|
}
|
|
|
|
if (boot_status)
|
|
wdat->wdd.bootstatus = WDIOF_CARDRESET;
|
|
|
|
/* Clear the boot status in case BIOS did not do it */
|
|
ret = wdat_wdt_run_action(wdat, ACPI_WDAT_SET_STATUS, 0, NULL);
|
|
if (ret && ret != -EOPNOTSUPP)
|
|
dev_err(&wdat->pdev->dev, "Failed to clear boot status\n");
|
|
}
|
|
|
|
static void wdat_wdt_set_running(struct wdat_wdt *wdat)
|
|
{
|
|
u32 running = 0;
|
|
int ret;
|
|
|
|
ret = wdat_wdt_run_action(wdat, ACPI_WDAT_GET_RUNNING_STATE, 0,
|
|
&running);
|
|
if (ret && ret != -EOPNOTSUPP)
|
|
dev_err(&wdat->pdev->dev, "Failed to read running state\n");
|
|
|
|
if (running)
|
|
set_bit(WDOG_HW_RUNNING, &wdat->wdd.status);
|
|
}
|
|
|
|
static int wdat_wdt_start(struct watchdog_device *wdd)
|
|
{
|
|
return wdat_wdt_run_action(to_wdat_wdt(wdd),
|
|
ACPI_WDAT_SET_RUNNING_STATE, 0, NULL);
|
|
}
|
|
|
|
static int wdat_wdt_stop(struct watchdog_device *wdd)
|
|
{
|
|
return wdat_wdt_run_action(to_wdat_wdt(wdd),
|
|
ACPI_WDAT_SET_STOPPED_STATE, 0, NULL);
|
|
}
|
|
|
|
static int wdat_wdt_ping(struct watchdog_device *wdd)
|
|
{
|
|
return wdat_wdt_run_action(to_wdat_wdt(wdd), ACPI_WDAT_RESET, 0, NULL);
|
|
}
|
|
|
|
static int wdat_wdt_set_timeout(struct watchdog_device *wdd,
|
|
unsigned int timeout)
|
|
{
|
|
struct wdat_wdt *wdat = to_wdat_wdt(wdd);
|
|
unsigned int periods;
|
|
int ret;
|
|
|
|
periods = timeout * 1000 / wdat->period;
|
|
ret = wdat_wdt_run_action(wdat, ACPI_WDAT_SET_COUNTDOWN, periods, NULL);
|
|
if (!ret)
|
|
wdd->timeout = timeout;
|
|
return ret;
|
|
}
|
|
|
|
static unsigned int wdat_wdt_get_timeleft(struct watchdog_device *wdd)
|
|
{
|
|
struct wdat_wdt *wdat = to_wdat_wdt(wdd);
|
|
u32 periods = 0;
|
|
|
|
wdat_wdt_run_action(wdat, ACPI_WDAT_GET_CURRENT_COUNTDOWN, 0, &periods);
|
|
return periods * wdat->period / 1000;
|
|
}
|
|
|
|
static const struct watchdog_info wdat_wdt_info = {
|
|
.options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE,
|
|
.firmware_version = 0,
|
|
.identity = "wdat_wdt",
|
|
};
|
|
|
|
static const struct watchdog_ops wdat_wdt_ops = {
|
|
.owner = THIS_MODULE,
|
|
.start = wdat_wdt_start,
|
|
.stop = wdat_wdt_stop,
|
|
.ping = wdat_wdt_ping,
|
|
.set_timeout = wdat_wdt_set_timeout,
|
|
.get_timeleft = wdat_wdt_get_timeleft,
|
|
};
|
|
|
|
static int wdat_wdt_probe(struct platform_device *pdev)
|
|
{
|
|
struct device *dev = &pdev->dev;
|
|
const struct acpi_wdat_entry *entries;
|
|
const struct acpi_table_wdat *tbl;
|
|
struct wdat_wdt *wdat;
|
|
struct resource *res;
|
|
void __iomem **regs;
|
|
acpi_status status;
|
|
int i, ret;
|
|
|
|
status = acpi_get_table(ACPI_SIG_WDAT, 0,
|
|
(struct acpi_table_header **)&tbl);
|
|
if (ACPI_FAILURE(status))
|
|
return -ENODEV;
|
|
|
|
wdat = devm_kzalloc(dev, sizeof(*wdat), GFP_KERNEL);
|
|
if (!wdat)
|
|
return -ENOMEM;
|
|
|
|
regs = devm_kcalloc(dev, pdev->num_resources, sizeof(*regs),
|
|
GFP_KERNEL);
|
|
if (!regs)
|
|
return -ENOMEM;
|
|
|
|
/* WDAT specification wants to have >= 1ms period */
|
|
if (tbl->timer_period < 1)
|
|
return -EINVAL;
|
|
if (tbl->min_count > tbl->max_count)
|
|
return -EINVAL;
|
|
|
|
wdat->period = tbl->timer_period;
|
|
wdat->wdd.min_hw_heartbeat_ms = wdat->period * tbl->min_count;
|
|
wdat->wdd.max_hw_heartbeat_ms = wdat->period * tbl->max_count;
|
|
wdat->stopped_in_sleep = tbl->flags & ACPI_WDAT_STOPPED;
|
|
wdat->wdd.info = &wdat_wdt_info;
|
|
wdat->wdd.ops = &wdat_wdt_ops;
|
|
wdat->pdev = pdev;
|
|
|
|
/* Request and map all resources */
|
|
for (i = 0; i < pdev->num_resources; i++) {
|
|
void __iomem *reg;
|
|
|
|
res = &pdev->resource[i];
|
|
if (resource_type(res) == IORESOURCE_MEM) {
|
|
reg = devm_ioremap_resource(dev, res);
|
|
if (IS_ERR(reg))
|
|
return PTR_ERR(reg);
|
|
} else if (resource_type(res) == IORESOURCE_IO) {
|
|
reg = devm_ioport_map(dev, res->start, 1);
|
|
if (!reg)
|
|
return -ENOMEM;
|
|
} else {
|
|
dev_err(dev, "Unsupported resource\n");
|
|
return -EINVAL;
|
|
}
|
|
|
|
regs[i] = reg;
|
|
}
|
|
|
|
entries = (struct acpi_wdat_entry *)(tbl + 1);
|
|
for (i = 0; i < tbl->entries; i++) {
|
|
const struct acpi_generic_address *gas;
|
|
struct wdat_instruction *instr;
|
|
struct list_head *instructions;
|
|
unsigned int action;
|
|
struct resource r;
|
|
int j;
|
|
|
|
action = entries[i].action;
|
|
if (action >= MAX_WDAT_ACTIONS) {
|
|
dev_dbg(dev, "Skipping unknown action: %u\n", action);
|
|
continue;
|
|
}
|
|
|
|
instr = devm_kzalloc(dev, sizeof(*instr), GFP_KERNEL);
|
|
if (!instr)
|
|
return -ENOMEM;
|
|
|
|
INIT_LIST_HEAD(&instr->node);
|
|
instr->entry = entries[i];
|
|
|
|
gas = &entries[i].register_region;
|
|
|
|
memset(&r, 0, sizeof(r));
|
|
r.start = gas->address;
|
|
r.end = r.start + gas->access_width - 1;
|
|
if (gas->space_id == ACPI_ADR_SPACE_SYSTEM_MEMORY) {
|
|
r.flags = IORESOURCE_MEM;
|
|
} else if (gas->space_id == ACPI_ADR_SPACE_SYSTEM_IO) {
|
|
r.flags = IORESOURCE_IO;
|
|
} else {
|
|
dev_dbg(dev, "Unsupported address space: %d\n",
|
|
gas->space_id);
|
|
continue;
|
|
}
|
|
|
|
/* Find the matching resource */
|
|
for (j = 0; j < pdev->num_resources; j++) {
|
|
res = &pdev->resource[j];
|
|
if (resource_contains(res, &r)) {
|
|
instr->reg = regs[j] + r.start - res->start;
|
|
break;
|
|
}
|
|
}
|
|
|
|
if (!instr->reg) {
|
|
dev_err(dev, "I/O resource not found\n");
|
|
return -EINVAL;
|
|
}
|
|
|
|
instructions = wdat->instructions[action];
|
|
if (!instructions) {
|
|
instructions = devm_kzalloc(dev,
|
|
sizeof(*instructions),
|
|
GFP_KERNEL);
|
|
if (!instructions)
|
|
return -ENOMEM;
|
|
|
|
INIT_LIST_HEAD(instructions);
|
|
wdat->instructions[action] = instructions;
|
|
}
|
|
|
|
list_add_tail(&instr->node, instructions);
|
|
}
|
|
|
|
wdat_wdt_boot_status(wdat);
|
|
wdat_wdt_set_running(wdat);
|
|
|
|
ret = wdat_wdt_enable_reboot(wdat);
|
|
if (ret)
|
|
return ret;
|
|
|
|
platform_set_drvdata(pdev, wdat);
|
|
|
|
watchdog_set_nowayout(&wdat->wdd, nowayout);
|
|
return devm_watchdog_register_device(dev, &wdat->wdd);
|
|
}
|
|
|
|
#ifdef CONFIG_PM_SLEEP
|
|
static int wdat_wdt_suspend_noirq(struct device *dev)
|
|
{
|
|
struct wdat_wdt *wdat = dev_get_drvdata(dev);
|
|
int ret;
|
|
|
|
if (!watchdog_active(&wdat->wdd))
|
|
return 0;
|
|
|
|
/*
|
|
* We need to stop the watchdog if firmare is not doing it or if we
|
|
* are going suspend to idle (where firmware is not involved). If
|
|
* firmware is stopping the watchdog we kick it here one more time
|
|
* to give it some time.
|
|
*/
|
|
wdat->stopped = false;
|
|
if (acpi_target_system_state() == ACPI_STATE_S0 ||
|
|
!wdat->stopped_in_sleep) {
|
|
ret = wdat_wdt_stop(&wdat->wdd);
|
|
if (!ret)
|
|
wdat->stopped = true;
|
|
} else {
|
|
ret = wdat_wdt_ping(&wdat->wdd);
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
static int wdat_wdt_resume_noirq(struct device *dev)
|
|
{
|
|
struct wdat_wdt *wdat = dev_get_drvdata(dev);
|
|
int ret;
|
|
|
|
if (!watchdog_active(&wdat->wdd))
|
|
return 0;
|
|
|
|
if (!wdat->stopped) {
|
|
/*
|
|
* Looks like the boot firmware reinitializes the watchdog
|
|
* before it hands off to the OS on resume from sleep so we
|
|
* stop and reprogram the watchdog here.
|
|
*/
|
|
ret = wdat_wdt_stop(&wdat->wdd);
|
|
if (ret)
|
|
return ret;
|
|
|
|
ret = wdat_wdt_set_timeout(&wdat->wdd, wdat->wdd.timeout);
|
|
if (ret)
|
|
return ret;
|
|
|
|
ret = wdat_wdt_enable_reboot(wdat);
|
|
if (ret)
|
|
return ret;
|
|
|
|
ret = wdat_wdt_ping(&wdat->wdd);
|
|
if (ret)
|
|
return ret;
|
|
}
|
|
|
|
return wdat_wdt_start(&wdat->wdd);
|
|
}
|
|
#endif
|
|
|
|
static const struct dev_pm_ops wdat_wdt_pm_ops = {
|
|
SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(wdat_wdt_suspend_noirq,
|
|
wdat_wdt_resume_noirq)
|
|
};
|
|
|
|
static struct platform_driver wdat_wdt_driver = {
|
|
.probe = wdat_wdt_probe,
|
|
.driver = {
|
|
.name = "wdat_wdt",
|
|
.pm = &wdat_wdt_pm_ops,
|
|
},
|
|
};
|
|
|
|
module_platform_driver(wdat_wdt_driver);
|
|
|
|
MODULE_AUTHOR("Mika Westerberg <mika.westerberg@linux.intel.com>");
|
|
MODULE_DESCRIPTION("ACPI Hardware Watchdog (WDAT) driver");
|
|
MODULE_LICENSE("GPL v2");
|
|
MODULE_ALIAS("platform:wdat_wdt");
|