/*
- * 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.
#include <linux/fs.h>
#include <linux/init.h>
#include <linux/kernel.h>
+#include <linux/timer.h>
#include <linux/miscdevice.h>
-#include <linux/platform_device.h>
+#include <linux/of_platform.h>
#include <linux/module.h>
#include <linux/watchdog.h>
-#include <asm/io.h>
-#include <asm/uaccess.h>
+#include <linux/io.h>
+#include <linux/uaccess.h>
+#include <sysdev/fsl_soc.h>
struct mpc83xx_wdt {
__be32 res0;
u8 res2[0xF0];
};
+struct mpc83xx_wdt_type {
+ int prescaler;
+ bool hw_enabled;
+};
+
static struct mpc83xx_wdt __iomem *wd_base;
static u16 timeout = 0xffff;
module_param(timeout, ushort, 0);
-MODULE_PARM_DESC(timeout, "Watchdog timeout in ticks. (0<timeout<65536, default=65535");
+MODULE_PARM_DESC(timeout,
+ "Watchdog timeout in ticks. (0<timeout<65536, default=65535");
static int reset = 1;
module_param(reset, bool, 0);
-MODULE_PARM_DESC(reset, "Watchdog Interrupt/Reset Mode. 0 = interrupt, 1 = reset");
+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
static unsigned int timeout_sec;
static unsigned long wdt_is_open;
-static spinlock_t wdt_spinlock;
+static DEFINE_SPINLOCK(wdt_spinlock);
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)
{
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)
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;
}
-static int mpc83xx_wdt_ioctl(struct inode *inode, struct file *file,
- unsigned int cmd, unsigned long arg)
+static long mpc83xx_wdt_ioctl(struct file *file, unsigned int cmd,
+ unsigned long arg)
{
void __user *argp = (void __user *)arg;
int __user *p = argp;
.owner = THIS_MODULE,
.llseek = no_llseek,
.write = mpc83xx_wdt_write,
- .ioctl = mpc83xx_wdt_ioctl,
+ .unlocked_ioctl = mpc83xx_wdt_ioctl,
.open = mpc83xx_wdt_open,
.release = mpc83xx_wdt_release,
};
.fops = &mpc83xx_wdt_fops,
};
-static int __devinit mpc83xx_wdt_probe(struct platform_device *dev)
+static int __devinit mpc83xx_wdt_probe(struct of_device *ofdev,
+ const struct of_device_id *match)
{
- struct resource *r;
int ret;
- unsigned int *freq = dev->dev.platform_data;
-
- /* get a pointer to the register memory */
- r = platform_get_resource(dev, IORESOURCE_MEM, 0);
-
- if (!r) {
- ret = -ENODEV;
- goto err_out;
- }
-
- wd_base = ioremap(r->start, sizeof (struct mpc83xx_wdt));
-
- if (wd_base == NULL) {
- ret = -ENOMEM;
- goto err_out;
+ 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(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) {
- printk(KERN_ERR "cannot register miscdev on minor=%d "
- "(err=%d)\n",
- WATCHDOG_MINOR, ret);
+ pr_err("cannot register miscdev on minor=%d (err=%d)\n",
+ WATCHDOG_MINOR, ret);
goto err_unmap;
}
/* Calculate the timeout in seconds */
if (prescale)
- timeout_sec = (timeout * 0x10000) / (*freq);
+ timeout_sec = (timeout * wdt_type->prescaler) / freq;
else
- timeout_sec = timeout / (*freq);
-
- printk(KERN_INFO "WDT driver for MPC83xx initialized. "
- "mode:%s timeout=%d (%d seconds)\n",
- reset ? "reset":"interrupt", timeout, timeout_sec);
-
- spin_lock_init(&wdt_spinlock);
-
+ 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);
-err_out:
return ret;
}
-static int __devexit mpc83xx_wdt_remove(struct platform_device *dev)
+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);
return 0;
}
-static struct platform_driver mpc83xx_wdt_driver = {
+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,
+ },
+ },
+ {},
+};
+MODULE_DEVICE_TABLE(of, mpc83xx_wdt_match);
+
+static struct of_platform_driver mpc83xx_wdt_driver = {
+ .match_table = mpc83xx_wdt_match,
.probe = mpc83xx_wdt_probe,
.remove = __devexit_p(mpc83xx_wdt_remove),
.driver = {
.name = "mpc83xx_wdt",
+ .owner = THIS_MODULE,
},
};
static int __init mpc83xx_wdt_init(void)
{
- return platform_driver_register(&mpc83xx_wdt_driver);
+ return of_register_platform_driver(&mpc83xx_wdt_driver);
}
static void __exit mpc83xx_wdt_exit(void)
{
- platform_driver_unregister(&mpc83xx_wdt_driver);
+ 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);
projects / linux-2.6 / blobdiff