diff options
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/watchdog/Kconfig | 4 | ||||
| -rw-r--r-- | drivers/watchdog/mpc83xx_wdt.c | 80 |
2 files changed, 74 insertions, 10 deletions
diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig index 48399e134c0..93329620f44 100644 --- a/drivers/watchdog/Kconfig +++ b/drivers/watchdog/Kconfig @@ -696,8 +696,8 @@ config 8xx_WDT depends on 8xx config 83xx_WDT - tristate "MPC83xx Watchdog Timer" - depends on PPC_83xx + tristate "MPC83xx/MPC86xx Watchdog Timer" + depends on PPC_83xx || PPC_86xx config MV64X60_WDT tristate "MV64X60 (Marvell Discovery) Watchdog Timer" diff --git a/drivers/watchdog/mpc83xx_wdt.c b/drivers/watchdog/mpc83xx_wdt.c index 5f1b7bff8f1..fa82ec99ba8 100644 --- a/drivers/watchdog/mpc83xx_wdt.c +++ b/drivers/watchdog/mpc83xx_wdt.c @@ -1,10 +1,12 @@ /* - * mpc83xx_wdt.c - MPC83xx watchdog userspace interface + * mpc83xx_wdt.c - MPC83xx/MPC86xx watchdog userspace interface * * Authors: Dave Updegraff <dave@cray.org> * Kumar Gala <galak@kernel.crashing.org> * Attribution: from 83xx_wst: Florian Schirmer <jolt@tuxbox.org> * ..and from sc520_wdt + * Copyright (c) 2008 MontaVista Software, Inc. + * Anton Vorontsov <avorontsov@ru.mvista.com> * * Note: it appears that you can only actually ENABLE or DISABLE the thing * once after POR. Once enabled, you cannot disable, and vice versa. @@ -18,6 +20,7 @@ #include <linux/fs.h> #include <linux/init.h> #include <linux/kernel.h> +#include <linux/timer.h> #include <linux/miscdevice.h> #include <linux/of_platform.h> #include <linux/module.h> @@ -39,6 +42,11 @@ struct mpc83xx_wdt { u8 res2[0xF0]; }; +struct mpc83xx_wdt_type { + int prescaler; + bool hw_enabled; +}; + static struct mpc83xx_wdt __iomem *wd_base; static u16 timeout = 0xffff; @@ -51,6 +59,11 @@ module_param(reset, bool, 0); MODULE_PARM_DESC(reset, "Watchdog Interrupt/Reset Mode. 0 = interrupt, 1 = reset"); +static int nowayout = WATCHDOG_NOWAYOUT; +module_param(nowayout, int, 0); +MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started " + "(default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); + /* * We always prescale, but if someone really doesn't want to they can set this * to 0 @@ -70,6 +83,22 @@ static void mpc83xx_wdt_keepalive(void) spin_unlock(&wdt_spinlock); } +static void mpc83xx_wdt_timer_ping(unsigned long arg); +static DEFINE_TIMER(wdt_timer, mpc83xx_wdt_timer_ping, 0, 0); + +static void mpc83xx_wdt_timer_ping(unsigned long arg) +{ + mpc83xx_wdt_keepalive(); + /* We're pinging it twice faster than needed, just to be sure. */ + mod_timer(&wdt_timer, jiffies + HZ * timeout_sec / 2); +} + +static void mpc83xx_wdt_pr_warn(const char *msg) +{ + pr_crit("mpc83xx_wdt: %s, expect the %s soon!\n", msg, + reset ? "reset" : "machine check exception"); +} + static ssize_t mpc83xx_wdt_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos) { @@ -85,7 +114,8 @@ static int mpc83xx_wdt_open(struct inode *inode, struct file *file) return -EBUSY; /* Once we start the watchdog we can't stop it */ - __module_get(THIS_MODULE); + if (nowayout) + __module_get(THIS_MODULE); /* Good, fire up the show */ if (prescale) @@ -97,13 +127,17 @@ static int mpc83xx_wdt_open(struct inode *inode, struct file *file) out_be32(&wd_base->swcrr, tmp); + del_timer_sync(&wdt_timer); + return nonseekable_open(inode, file); } static int mpc83xx_wdt_release(struct inode *inode, struct file *file) { - printk(KERN_CRIT "Unexpected close, not stopping watchdog!\n"); - mpc83xx_wdt_keepalive(); + if (!nowayout) + mpc83xx_wdt_timer_ping(0); + else + mpc83xx_wdt_pr_warn("watchdog closed"); clear_bit(0, &wdt_is_open); return 0; } @@ -154,15 +188,25 @@ static int __devinit mpc83xx_wdt_probe(struct of_device *ofdev, const struct of_device_id *match) { int ret; + struct device_node *np = ofdev->node; + struct mpc83xx_wdt_type *wdt_type = match->data; u32 freq = fsl_get_sys_freq(); + bool enabled; if (!freq || freq == -1) return -EINVAL; - wd_base = of_iomap(ofdev->node, 0); + wd_base = of_iomap(np, 0); if (!wd_base) return -ENOMEM; + enabled = in_be32(&wd_base->swcrr) & SWCRR_SWEN; + if (!enabled && wdt_type->hw_enabled) { + pr_info("mpc83xx_wdt: could not be enabled in software\n"); + ret = -ENOSYS; + goto err_unmap; + } + ret = misc_register(&mpc83xx_wdt_miscdev); if (ret) { pr_err("cannot register miscdev on minor=%d (err=%d)\n", @@ -172,13 +216,21 @@ static int __devinit mpc83xx_wdt_probe(struct of_device *ofdev, /* Calculate the timeout in seconds */ if (prescale) - timeout_sec = (timeout * 0x10000) / freq; + timeout_sec = (timeout * wdt_type->prescaler) / freq; else timeout_sec = timeout / freq; pr_info("WDT driver for MPC83xx initialized. mode:%s timeout=%d " "(%d seconds)\n", reset ? "reset" : "interrupt", timeout, timeout_sec); + + /* + * If the watchdog was previously enabled or we're running on + * MPC86xx, we should ping the wdt from the kernel until the + * userspace handles it. + */ + if (enabled) + mpc83xx_wdt_timer_ping(0); return 0; err_unmap: iounmap(wd_base); @@ -187,6 +239,8 @@ err_unmap: static int __devexit mpc83xx_wdt_remove(struct of_device *ofdev) { + mpc83xx_wdt_pr_warn("watchdog removed"); + del_timer_sync(&wdt_timer); misc_deregister(&mpc83xx_wdt_miscdev); iounmap(wd_base); @@ -196,6 +250,16 @@ static int __devexit mpc83xx_wdt_remove(struct of_device *ofdev) static const struct of_device_id mpc83xx_wdt_match[] = { { .compatible = "mpc83xx_wdt", + .data = &(struct mpc83xx_wdt_type) { + .prescaler = 0x10000, + }, + }, + { + .compatible = "fsl,mpc8610-wdt", + .data = &(struct mpc83xx_wdt_type) { + .prescaler = 0x10000, + .hw_enabled = true, + }, }, {}, }; @@ -221,10 +285,10 @@ static void __exit mpc83xx_wdt_exit(void) of_unregister_platform_driver(&mpc83xx_wdt_driver); } -module_init(mpc83xx_wdt_init); +subsys_initcall(mpc83xx_wdt_init); module_exit(mpc83xx_wdt_exit); MODULE_AUTHOR("Dave Updegraff, Kumar Gala"); -MODULE_DESCRIPTION("Driver for watchdog timer in MPC83xx uProcessor"); +MODULE_DESCRIPTION("Driver for watchdog timer in MPC83xx/MPC86xx uProcessors"); MODULE_LICENSE("GPL"); MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR); |