/*
- * drivers/char/watchdog/booke_wdt.c
- *
* Watchdog timer for PowerPC Book-E systems
*
* Author: Matthew McClintock
* Maintainer: Kumar Gala <galak@kernel.crashing.org>
*
- * Copyright 2005 Freescale Semiconductor Inc.
+ * Copyright 2005, 2008 Freescale Semiconductor Inc.
*
* 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
#include <linux/module.h>
#include <linux/fs.h>
+#include <linux/smp.h>
#include <linux/miscdevice.h>
#include <linux/notifier.h>
#include <linux/watchdog.h>
+#include <linux/uaccess.h>
#include <asm/reg_booke.h>
-#include <asm/uaccess.h>
#include <asm/system.h>
+#include <asm/time.h>
+#include <asm/div64.h>
/* If the kernel parameter wdt=1, the watchdog will be enabled at boot.
* Also, the wdt_period sets the watchdog timer period timeout.
*/
#ifdef CONFIG_FSL_BOOKE
-#define WDT_PERIOD_DEFAULT 63 /* Ex. wdt_period=28 bus=333Mhz , reset=~40sec */
+#define WDT_PERIOD_DEFAULT 38 /* Ex. wdt_period=28 bus=333Mhz,reset=~40sec */
#else
#define WDT_PERIOD_DEFAULT 3 /* Refer to the PPC40x and PPC4xx manuals */
#endif /* for timing information */
-u32 booke_wdt_enabled = 0;
+u32 booke_wdt_enabled;
u32 booke_wdt_period = WDT_PERIOD_DEFAULT;
#ifdef CONFIG_FSL_BOOKE
-#define WDTP(x) ((((63-x)&0x3)<<30)|(((63-x)&0x3c)<<15))
+#define WDTP(x) ((((x)&0x3)<<30)|(((x)&0x3c)<<15))
+#define WDTP_MASK (WDTP(0))
#else
#define WDTP(x) (TCR_WP(x))
+#define WDTP_MASK (TCR_WP_MASK)
#endif
-/*
- * booke_wdt_ping:
+static DEFINE_SPINLOCK(booke_wdt_lock);
+
+/* For the specified period, determine the number of seconds
+ * corresponding to the reset time. There will be a watchdog
+ * exception at approximately 3/5 of this time.
+ *
+ * The formula to calculate this is given by:
+ * 2.5 * (2^(63-period+1)) / timebase_freq
+ *
+ * In order to simplify things, we assume that period is
+ * at least 1. This will still result in a very long timeout.
*/
-static __inline__ void booke_wdt_ping(void)
+static unsigned long long period_to_sec(unsigned int period)
{
- mtspr(SPRN_TSR, TSR_ENW|TSR_WIS);
+ unsigned long long tmp = 1ULL << (64 - period);
+ unsigned long tmp2 = ppc_tb_freq;
+
+ /* tmp may be a very large number and we don't want to overflow,
+ * so divide the timebase freq instead of multiplying tmp
+ */
+ tmp2 = tmp2 / 5 * 2;
+
+ do_div(tmp, tmp2);
+ return tmp;
}
/*
- * booke_wdt_enable:
+ * This procedure will find the highest period which will give a timeout
+ * greater than the one required. e.g. for a bus speed of 66666666 and
+ * and a parameter of 2 secs, then this procedure will return a value of 38.
*/
-static __inline__ void booke_wdt_enable(void)
+static unsigned int sec_to_period(unsigned int secs)
+{
+ unsigned int period;
+ for (period = 63; period > 0; period--) {
+ if (period_to_sec(period) >= secs)
+ return period;
+ }
+ return 0;
+}
+
+static void __booke_wdt_ping(void *data)
+{
+ mtspr(SPRN_TSR, TSR_ENW|TSR_WIS);
+}
+
+static void booke_wdt_ping(void)
+{
+ on_each_cpu(__booke_wdt_ping, NULL, 0);
+}
+
+static void __booke_wdt_enable(void *data)
{
u32 val;
/* clear status before enabling watchdog */
- booke_wdt_ping();
+ __booke_wdt_ping(NULL);
val = mfspr(SPRN_TCR);
+ val &= ~WDTP_MASK;
val |= (TCR_WIE|TCR_WRC(WRC_CHIP)|WDTP(booke_wdt_period));
mtspr(SPRN_TCR, val);
}
-/*
- * booke_wdt_write:
- */
-static ssize_t booke_wdt_write (struct file *file, const char __user *buf,
+static ssize_t booke_wdt_write(struct file *file, const char __user *buf,
size_t count, loff_t *ppos)
{
booke_wdt_ping();
return count;
}
-static struct watchdog_info ident = {
- .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING,
- .firmware_version = 0,
- .identity = "PowerPC Book-E Watchdog",
+static const struct watchdog_info ident = {
+ .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING,
+ .identity = "PowerPC Book-E Watchdog",
};
-/*
- * booke_wdt_ioctl:
- */
-static int booke_wdt_ioctl (struct inode *inode, struct file *file,
- unsigned int cmd, unsigned long arg)
+static long booke_wdt_ioctl(struct file *file,
+ unsigned int cmd, unsigned long arg)
{
u32 tmp = 0;
u32 __user *p = (u32 __user *)arg;
switch (cmd) {
case WDIOC_GETSUPPORT:
- if (copy_to_user ((struct watchdog_info __user *) arg, &ident,
- sizeof(struct watchdog_info)))
+ if (copy_to_user((void *)arg, &ident, sizeof(ident)))
return -EFAULT;
case WDIOC_GETSTATUS:
return put_user(ident.options, p);
tmp = mfspr(SPRN_TSR) & TSR_WRS(3);
/* returns 1 if last reset was caused by the WDT */
return (tmp ? 1 : 0);
- case WDIOC_KEEPALIVE:
- booke_wdt_ping();
- return 0;
- case WDIOC_SETTIMEOUT:
- if (get_user(booke_wdt_period, p))
- return -EFAULT;
- mtspr(SPRN_TCR, (mfspr(SPRN_TCR)&~WDTP(0))|WDTP(booke_wdt_period));
- return 0;
- case WDIOC_GETTIMEOUT:
- return put_user(booke_wdt_period, p);
case WDIOC_SETOPTIONS:
if (get_user(tmp, p))
return -EINVAL;
} else
return -EINVAL;
return 0;
+ case WDIOC_KEEPALIVE:
+ booke_wdt_ping();
+ return 0;
+ case WDIOC_SETTIMEOUT:
+ if (get_user(tmp, p))
+ return -EFAULT;
+#ifdef CONFIG_FSL_BOOKE
+ /* period of 1 gives the largest possible timeout */
+ if (tmp > period_to_sec(1))
+ return -EINVAL;
+ booke_wdt_period = sec_to_period(tmp);
+#else
+ booke_wdt_period = tmp;
+#endif
+ mtspr(SPRN_TCR, (mfspr(SPRN_TCR) & ~WDTP_MASK) |
+ WDTP(booke_wdt_period));
+ return 0;
+ case WDIOC_GETTIMEOUT:
+ return put_user(booke_wdt_period, p);
default:
return -ENOTTY;
}
return 0;
}
-/*
- * booke_wdt_open:
- */
-static int booke_wdt_open (struct inode *inode, struct file *file)
+
+static int booke_wdt_open(struct inode *inode, struct file *file)
{
+ spin_lock(&booke_wdt_lock);
if (booke_wdt_enabled == 0) {
booke_wdt_enabled = 1;
- booke_wdt_enable();
- printk (KERN_INFO "PowerPC Book-E Watchdog Timer Enabled (wdt_period=%d)\n",
+ on_each_cpu(__booke_wdt_enable, NULL, 0);
+ printk(KERN_INFO
+ "PowerPC Book-E Watchdog Timer Enabled (wdt_period=%d)\n",
booke_wdt_period);
}
+ spin_unlock(&booke_wdt_lock);
return nonseekable_open(inode, file);
}
static const struct file_operations booke_wdt_fops = {
- .owner = THIS_MODULE,
- .llseek = no_llseek,
- .write = booke_wdt_write,
- .ioctl = booke_wdt_ioctl,
- .open = booke_wdt_open,
+ .owner = THIS_MODULE,
+ .llseek = no_llseek,
+ .write = booke_wdt_write,
+ .unlocked_ioctl = booke_wdt_ioctl,
+ .open = booke_wdt_open,
};
static struct miscdevice booke_wdt_miscdev = {
- .minor = WATCHDOG_MINOR,
- .name = "watchdog",
- .fops = &booke_wdt_fops,
+ .minor = WATCHDOG_MINOR,
+ .name = "watchdog",
+ .fops = &booke_wdt_fops,
};
static void __exit booke_wdt_exit(void)
misc_deregister(&booke_wdt_miscdev);
}
-/*
- * booke_wdt_init:
- */
static int __init booke_wdt_init(void)
{
int ret = 0;
- printk (KERN_INFO "PowerPC Book-E Watchdog Timer Loaded\n");
+ printk(KERN_INFO "PowerPC Book-E Watchdog Timer Loaded\n");
ident.firmware_version = cur_cpu_spec->pvr_value;
ret = misc_register(&booke_wdt_miscdev);
if (ret) {
- printk (KERN_CRIT "Cannot register miscdev on minor=%d (err=%d)\n",
+ printk(KERN_CRIT "Cannot register miscdev on minor=%d: %d\n",
WATCHDOG_MINOR, ret);
return ret;
}
+ spin_lock(&booke_wdt_lock);
if (booke_wdt_enabled == 1) {
- printk (KERN_INFO "PowerPC Book-E Watchdog Timer Enabled (wdt_period=%d)\n",
+ printk(KERN_INFO
+ "PowerPC Book-E Watchdog Timer Enabled (wdt_period=%d)\n",
booke_wdt_period);
- booke_wdt_enable();
+ on_each_cpu(__booke_wdt_enable, NULL, 0);
}
+ spin_unlock(&booke_wdt_lock);
return ret;
}
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff