mirror of
https://github.com/torvalds/linux.git
synced 2024-12-05 10:32:35 +00:00
33a9f5bc15
Since the WDT is what's used to drive restart and power off, it makes more sense to keep it there, where the regs are already mapped and definitions for them provided. Note that this means you may need to add CONFIG_BCM2835_WDT to retain functionality of your kernel. Signed-off-by: Eric Anholt <eric@anholt.net> Acked-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Lee Jones <lee.jones@linaro.org>
247 lines
6.7 KiB
C
247 lines
6.7 KiB
C
/*
|
|
* Watchdog driver for Broadcom BCM2835
|
|
*
|
|
* "bcm2708_wdog" driver written by Luke Diamand that was obtained from
|
|
* branch "rpi-3.6.y" of git://github.com/raspberrypi/linux.git was used
|
|
* as a hardware reference for the Broadcom BCM2835 watchdog timer.
|
|
*
|
|
* Copyright (C) 2013 Lubomir Rintel <lkundrak@v3.sk>
|
|
*
|
|
* This program is free software; you can redistribute it and/or modify it
|
|
* under the terms of the GNU General Public License as published by the
|
|
* Free Software Foundation; either version 2 of the License, or (at your
|
|
* option) any later version.
|
|
*/
|
|
|
|
#include <linux/delay.h>
|
|
#include <linux/reboot.h>
|
|
#include <linux/types.h>
|
|
#include <linux/module.h>
|
|
#include <linux/io.h>
|
|
#include <linux/watchdog.h>
|
|
#include <linux/platform_device.h>
|
|
#include <linux/of_address.h>
|
|
#include <linux/of_platform.h>
|
|
|
|
#define PM_RSTC 0x1c
|
|
#define PM_RSTS 0x20
|
|
#define PM_WDOG 0x24
|
|
|
|
#define PM_PASSWORD 0x5a000000
|
|
|
|
#define PM_WDOG_TIME_SET 0x000fffff
|
|
#define PM_RSTC_WRCFG_CLR 0xffffffcf
|
|
#define PM_RSTS_HADWRH_SET 0x00000040
|
|
#define PM_RSTC_WRCFG_SET 0x00000030
|
|
#define PM_RSTC_WRCFG_FULL_RESET 0x00000020
|
|
#define PM_RSTC_RESET 0x00000102
|
|
|
|
#define SECS_TO_WDOG_TICKS(x) ((x) << 16)
|
|
#define WDOG_TICKS_TO_SECS(x) ((x) >> 16)
|
|
|
|
struct bcm2835_wdt {
|
|
void __iomem *base;
|
|
spinlock_t lock;
|
|
struct notifier_block restart_handler;
|
|
};
|
|
|
|
static unsigned int heartbeat;
|
|
static bool nowayout = WATCHDOG_NOWAYOUT;
|
|
|
|
static int bcm2835_wdt_start(struct watchdog_device *wdog)
|
|
{
|
|
struct bcm2835_wdt *wdt = watchdog_get_drvdata(wdog);
|
|
uint32_t cur;
|
|
unsigned long flags;
|
|
|
|
spin_lock_irqsave(&wdt->lock, flags);
|
|
|
|
writel_relaxed(PM_PASSWORD | (SECS_TO_WDOG_TICKS(wdog->timeout) &
|
|
PM_WDOG_TIME_SET), wdt->base + PM_WDOG);
|
|
cur = readl_relaxed(wdt->base + PM_RSTC);
|
|
writel_relaxed(PM_PASSWORD | (cur & PM_RSTC_WRCFG_CLR) |
|
|
PM_RSTC_WRCFG_FULL_RESET, wdt->base + PM_RSTC);
|
|
|
|
spin_unlock_irqrestore(&wdt->lock, flags);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int bcm2835_wdt_stop(struct watchdog_device *wdog)
|
|
{
|
|
struct bcm2835_wdt *wdt = watchdog_get_drvdata(wdog);
|
|
|
|
writel_relaxed(PM_PASSWORD | PM_RSTC_RESET, wdt->base + PM_RSTC);
|
|
dev_info(wdog->dev, "Watchdog timer stopped");
|
|
return 0;
|
|
}
|
|
|
|
static int bcm2835_wdt_set_timeout(struct watchdog_device *wdog, unsigned int t)
|
|
{
|
|
wdog->timeout = t;
|
|
return 0;
|
|
}
|
|
|
|
static unsigned int bcm2835_wdt_get_timeleft(struct watchdog_device *wdog)
|
|
{
|
|
struct bcm2835_wdt *wdt = watchdog_get_drvdata(wdog);
|
|
|
|
uint32_t ret = readl_relaxed(wdt->base + PM_WDOG);
|
|
return WDOG_TICKS_TO_SECS(ret & PM_WDOG_TIME_SET);
|
|
}
|
|
|
|
static struct watchdog_ops bcm2835_wdt_ops = {
|
|
.owner = THIS_MODULE,
|
|
.start = bcm2835_wdt_start,
|
|
.stop = bcm2835_wdt_stop,
|
|
.set_timeout = bcm2835_wdt_set_timeout,
|
|
.get_timeleft = bcm2835_wdt_get_timeleft,
|
|
};
|
|
|
|
static struct watchdog_info bcm2835_wdt_info = {
|
|
.options = WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE |
|
|
WDIOF_KEEPALIVEPING,
|
|
.identity = "Broadcom BCM2835 Watchdog timer",
|
|
};
|
|
|
|
static struct watchdog_device bcm2835_wdt_wdd = {
|
|
.info = &bcm2835_wdt_info,
|
|
.ops = &bcm2835_wdt_ops,
|
|
.min_timeout = 1,
|
|
.max_timeout = WDOG_TICKS_TO_SECS(PM_WDOG_TIME_SET),
|
|
.timeout = WDOG_TICKS_TO_SECS(PM_WDOG_TIME_SET),
|
|
};
|
|
|
|
static int
|
|
bcm2835_restart(struct notifier_block *this, unsigned long mode, void *cmd)
|
|
{
|
|
struct bcm2835_wdt *wdt = container_of(this, struct bcm2835_wdt,
|
|
restart_handler);
|
|
u32 val;
|
|
|
|
/* use a timeout of 10 ticks (~150us) */
|
|
writel_relaxed(10 | PM_PASSWORD, wdt->base + PM_WDOG);
|
|
val = readl_relaxed(wdt->base + PM_RSTC);
|
|
val &= PM_RSTC_WRCFG_CLR;
|
|
val |= PM_PASSWORD | PM_RSTC_WRCFG_FULL_RESET;
|
|
writel_relaxed(val, wdt->base + PM_RSTC);
|
|
|
|
/* No sleeping, possibly atomic. */
|
|
mdelay(1);
|
|
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* We can't really power off, but if we do the normal reset scheme, and
|
|
* indicate to bootcode.bin not to reboot, then most of the chip will be
|
|
* powered off.
|
|
*/
|
|
static void bcm2835_power_off(void)
|
|
{
|
|
struct device_node *np =
|
|
of_find_compatible_node(NULL, NULL, "brcm,bcm2835-pm-wdt");
|
|
struct platform_device *pdev = of_find_device_by_node(np);
|
|
struct bcm2835_wdt *wdt = platform_get_drvdata(pdev);
|
|
u32 val;
|
|
|
|
/*
|
|
* We set the watchdog hard reset bit here to distinguish this reset
|
|
* from the normal (full) reset. bootcode.bin will not reboot after a
|
|
* hard reset.
|
|
*/
|
|
val = readl_relaxed(wdt->base + PM_RSTS);
|
|
val &= PM_RSTC_WRCFG_CLR;
|
|
val |= PM_PASSWORD | PM_RSTS_HADWRH_SET;
|
|
writel_relaxed(val, wdt->base + PM_RSTS);
|
|
|
|
/* Continue with normal reset mechanism */
|
|
bcm2835_restart(&wdt->restart_handler, REBOOT_HARD, NULL);
|
|
}
|
|
|
|
static int bcm2835_wdt_probe(struct platform_device *pdev)
|
|
{
|
|
struct device *dev = &pdev->dev;
|
|
struct device_node *np = dev->of_node;
|
|
struct bcm2835_wdt *wdt;
|
|
int err;
|
|
|
|
wdt = devm_kzalloc(dev, sizeof(struct bcm2835_wdt), GFP_KERNEL);
|
|
if (!wdt)
|
|
return -ENOMEM;
|
|
platform_set_drvdata(pdev, wdt);
|
|
|
|
spin_lock_init(&wdt->lock);
|
|
|
|
wdt->base = of_iomap(np, 0);
|
|
if (!wdt->base) {
|
|
dev_err(dev, "Failed to remap watchdog regs");
|
|
return -ENODEV;
|
|
}
|
|
|
|
watchdog_set_drvdata(&bcm2835_wdt_wdd, wdt);
|
|
watchdog_init_timeout(&bcm2835_wdt_wdd, heartbeat, dev);
|
|
watchdog_set_nowayout(&bcm2835_wdt_wdd, nowayout);
|
|
err = watchdog_register_device(&bcm2835_wdt_wdd);
|
|
if (err) {
|
|
dev_err(dev, "Failed to register watchdog device");
|
|
iounmap(wdt->base);
|
|
return err;
|
|
}
|
|
|
|
wdt->restart_handler.notifier_call = bcm2835_restart;
|
|
wdt->restart_handler.priority = 128;
|
|
register_restart_handler(&wdt->restart_handler);
|
|
if (pm_power_off == NULL)
|
|
pm_power_off = bcm2835_power_off;
|
|
|
|
dev_info(dev, "Broadcom BCM2835 watchdog timer");
|
|
return 0;
|
|
}
|
|
|
|
static int bcm2835_wdt_remove(struct platform_device *pdev)
|
|
{
|
|
struct bcm2835_wdt *wdt = platform_get_drvdata(pdev);
|
|
|
|
unregister_restart_handler(&wdt->restart_handler);
|
|
if (pm_power_off == bcm2835_power_off)
|
|
pm_power_off = NULL;
|
|
watchdog_unregister_device(&bcm2835_wdt_wdd);
|
|
iounmap(wdt->base);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void bcm2835_wdt_shutdown(struct platform_device *pdev)
|
|
{
|
|
bcm2835_wdt_stop(&bcm2835_wdt_wdd);
|
|
}
|
|
|
|
static const struct of_device_id bcm2835_wdt_of_match[] = {
|
|
{ .compatible = "brcm,bcm2835-pm-wdt", },
|
|
{},
|
|
};
|
|
MODULE_DEVICE_TABLE(of, bcm2835_wdt_of_match);
|
|
|
|
static struct platform_driver bcm2835_wdt_driver = {
|
|
.probe = bcm2835_wdt_probe,
|
|
.remove = bcm2835_wdt_remove,
|
|
.shutdown = bcm2835_wdt_shutdown,
|
|
.driver = {
|
|
.name = "bcm2835-wdt",
|
|
.of_match_table = bcm2835_wdt_of_match,
|
|
},
|
|
};
|
|
module_platform_driver(bcm2835_wdt_driver);
|
|
|
|
module_param(heartbeat, uint, 0);
|
|
MODULE_PARM_DESC(heartbeat, "Initial watchdog heartbeat in seconds");
|
|
|
|
module_param(nowayout, bool, 0);
|
|
MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="
|
|
__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
|
|
|
|
MODULE_AUTHOR("Lubomir Rintel <lkundrak@v3.sk>");
|
|
MODULE_DESCRIPTION("Driver for Broadcom BCM2835 watchdog timer");
|
|
MODULE_LICENSE("GPL");
|