* based on
* SoftDog 0.05: A Software Watchdog Device
*
- * (c) Copyright 1996 Alan Cox <alan@redhat.com>, All Rights Reserved.
+ * (c) Copyright 1996 Alan Cox <alan@lxorguk.ukuu.org.uk>,
+ * All Rights Reserved.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
*
*/
-#include <linux/module.h>
-#include <linux/types.h>
-#include <linux/kernel.h>
-#include <linux/fs.h>
-#include <linux/mm.h>
-#include <linux/miscdevice.h>
-#include <linux/watchdog.h>
-#include <linux/reboot.h>
-#include <linux/smp_lock.h>
-#include <linux/init.h>
-#include <linux/platform_device.h>
-#include <linux/uaccess.h>
+#include <linux/module.h> /* For module specific items */
+#include <linux/moduleparam.h> /* For new moduleparam's */
+#include <linux/types.h> /* For standard types (like size_t) */
+#include <linux/errno.h> /* For the -ENODEV/... values */
+#include <linux/kernel.h> /* For printk/panic/... */
+#include <linux/fs.h> /* For file operations */
+#include <linux/miscdevice.h> /* For MODULE_ALIAS_MISCDEV
+ (WATCHDOG_MINOR) */
+#include <linux/watchdog.h> /* For the watchdog specific items */
+#include <linux/init.h> /* For __init/__exit/... */
+#include <linux/platform_device.h> /* For platform_driver framework */
+#include <linux/spinlock.h> /* For spin_lock/spin_unlock/... */
+#include <linux/uaccess.h> /* For copy_to_user/put_user/... */
-#include <asm/bootinfo.h>
-#include <asm/time.h>
-#include <asm/mach-rc32434/integ.h>
+#include <asm/mach-rc32434/integ.h> /* For the Watchdog registers */
-#define MAX_TIMEOUT 20
-#define RC32434_WDT_INTERVAL (15 * HZ)
+#define PFX KBUILD_MODNAME ": "
-#define VERSION "0.2"
+#define VERSION "1.0"
static struct {
- struct completion stop;
- int running;
- struct timer_list timer;
- int queue;
- int default_ticks;
unsigned long inuse;
+ spinlock_t io_lock;
} rc32434_wdt_device;
static struct integ __iomem *wdt_reg;
-static int ticks = 100 * HZ;
static int expect_close;
-static int timeout;
+
+/* Board internal clock speed in Hz,
+ * the watchdog timer ticks at. */
+extern unsigned int idt_cpu_freq;
+
+/* translate wtcompare value to seconds and vice versa */
+#define WTCOMP2SEC(x) (x / idt_cpu_freq)
+#define SEC2WTCOMP(x) (x * idt_cpu_freq)
+
+/* Use a default timeout of 20s. This should be
+ * safe for CPU clock speeds up to 400MHz, as
+ * ((2 ^ 32) - 1) / (400MHz / 2) = 21s. */
+#define WATCHDOG_TIMEOUT 20
+
+static int timeout = WATCHDOG_TIMEOUT;
+module_param(timeout, int, 0);
+MODULE_PARM_DESC(timeout, "Watchdog timeout value, in seconds (default="
+ WATCHDOG_TIMEOUT ")");
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) ")");
+/* apply or and nand masks to data read from addr and write back */
+#define SET_BITS(addr, or, nand) \
+ writel((readl(&addr) | or) & ~nand, &addr)
-static void rc32434_wdt_start(void)
+static int rc32434_wdt_set(int new_timeout)
{
- u32 val;
-
- if (!rc32434_wdt_device.inuse) {
- writel(0, &wdt_reg->wtcount);
+ int max_to = WTCOMP2SEC((u32)-1);
- val = RC32434_ERR_WRE;
- writel(readl(&wdt_reg->errcs) | val, &wdt_reg->errcs);
-
- val = RC32434_WTC_EN;
- writel(readl(&wdt_reg->wtc) | val, &wdt_reg->wtc);
+ if (new_timeout < 0 || new_timeout > max_to) {
+ printk(KERN_ERR PFX "timeout value must be between 0 and %d",
+ max_to);
+ return -EINVAL;
}
- rc32434_wdt_device.running++;
+ timeout = new_timeout;
+ spin_lock(&rc32434_wdt_device.io_lock);
+ writel(SEC2WTCOMP(timeout), &wdt_reg->wtcompare);
+ spin_unlock(&rc32434_wdt_device.io_lock);
+
+ return 0;
}
-static void rc32434_wdt_stop(void)
+static void rc32434_wdt_start(void)
{
- u32 val;
+ u32 or, nand;
- if (rc32434_wdt_device.running) {
+ spin_lock(&rc32434_wdt_device.io_lock);
- val = ~RC32434_WTC_EN;
- writel(readl(&wdt_reg->wtc) & val, &wdt_reg->wtc);
+ /* zero the counter before enabling */
+ writel(0, &wdt_reg->wtcount);
- val = ~RC32434_ERR_WRE;
- writel(readl(&wdt_reg->errcs) & val, &wdt_reg->errcs);
+ /* don't generate a non-maskable interrupt,
+ * do a warm reset instead */
+ nand = 1 << RC32434_ERR_WNE;
+ or = 1 << RC32434_ERR_WRE;
- rc32434_wdt_device.running = 0;
- }
-}
+ /* reset the ERRCS timeout bit in case it's set */
+ nand |= 1 << RC32434_ERR_WTO;
-static void rc32434_wdt_set(int new_timeout)
-{
- u32 cmp = new_timeout * HZ;
- u32 state, val;
+ SET_BITS(wdt_reg->errcs, or, nand);
- timeout = new_timeout;
- /*
- * store and disable WTC
- */
- state = (u32)(readl(&wdt_reg->wtc) & RC32434_WTC_EN);
- val = ~RC32434_WTC_EN;
- writel(readl(&wdt_reg->wtc) & val, &wdt_reg->wtc);
+ /* set the timeout (either default or based on module param) */
+ rc32434_wdt_set(timeout);
- writel(0, &wdt_reg->wtcount);
- writel(cmp, &wdt_reg->wtcompare);
+ /* reset WTC timeout bit and enable WDT */
+ nand = 1 << RC32434_WTC_TO;
+ or = 1 << RC32434_WTC_EN;
- /*
- * restore WTC
- */
+ SET_BITS(wdt_reg->wtc, or, nand);
- writel(readl(&wdt_reg->wtc) | state, &wdt_reg);
+ spin_unlock(&rc32434_wdt_device.io_lock);
+ printk(KERN_INFO PFX "Started watchdog timer.\n");
}
-static void rc32434_wdt_reset(void)
+static void rc32434_wdt_stop(void)
{
- ticks = rc32434_wdt_device.default_ticks;
+ spin_lock(&rc32434_wdt_device.io_lock);
+
+ /* Disable WDT */
+ SET_BITS(wdt_reg->wtc, 0, 1 << RC32434_WTC_EN);
+
+ spin_unlock(&rc32434_wdt_device.io_lock);
+ printk(KERN_INFO PFX "Stopped watchdog timer.\n");
}
-static void rc32434_wdt_update(unsigned long unused)
+static void rc32434_wdt_ping(void)
{
- if (rc32434_wdt_device.running)
- ticks--;
-
+ spin_lock(&rc32434_wdt_device.io_lock);
writel(0, &wdt_reg->wtcount);
-
- if (rc32434_wdt_device.queue && ticks)
- mod_timer(&rc32434_wdt_device.timer,
- jiffies + RC32434_WDT_INTERVAL);
- else
- complete(&rc32434_wdt_device.stop);
+ spin_unlock(&rc32434_wdt_device.io_lock);
}
static int rc32434_wdt_open(struct inode *inode, struct file *file)
if (nowayout)
__module_get(THIS_MODULE);
+ rc32434_wdt_start();
+ rc32434_wdt_ping();
+
return nonseekable_open(inode, file);
}
static int rc32434_wdt_release(struct inode *inode, struct file *file)
{
- if (expect_close && nowayout == 0) {
+ if (expect_close == 42) {
rc32434_wdt_stop();
- printk(KERN_INFO KBUILD_MODNAME ": disabling watchdog timer\n");
module_put(THIS_MODULE);
- } else
- printk(KERN_CRIT KBUILD_MODNAME
- ": device closed unexpectedly. WDT will not stop !\n");
-
+ } else {
+ printk(KERN_CRIT PFX
+ "device closed unexpectedly. WDT will not stop!\n");
+ rc32434_wdt_ping();
+ }
clear_bit(0, &rc32434_wdt_device.inuse);
return 0;
}
if (get_user(c, data + i))
return -EFAULT;
if (c == 'V')
- expect_close = 1;
+ expect_close = 42;
}
}
- rc32434_wdt_update(0);
+ rc32434_wdt_ping();
return len;
}
return 0;
.identity = "RC32434_WDT Watchdog",
};
switch (cmd) {
- case WDIOC_KEEPALIVE:
- rc32434_wdt_reset();
+ case WDIOC_GETSUPPORT:
+ if (copy_to_user(argp, &ident, sizeof(ident)))
+ return -EFAULT;
break;
case WDIOC_GETSTATUS:
case WDIOC_GETBOOTSTATUS:
- value = readl(&wdt_reg->wtcount);
+ value = 0;
if (copy_to_user(argp, &value, sizeof(int)))
return -EFAULT;
break;
- case WDIOC_GETSUPPORT:
- if (copy_to_user(argp, &ident, sizeof(ident)))
- return -EFAULT;
- break;
case WDIOC_SETOPTIONS:
if (copy_from_user(&value, argp, sizeof(int)))
return -EFAULT;
break;
case WDIOS_DISABLECARD:
rc32434_wdt_stop();
+ break;
default:
return -EINVAL;
}
break;
+ case WDIOC_KEEPALIVE:
+ rc32434_wdt_ping();
+ break;
case WDIOC_SETTIMEOUT:
if (copy_from_user(&new_timeout, argp, sizeof(int)))
return -EFAULT;
- if (new_timeout < 1)
+ if (rc32434_wdt_set(new_timeout))
return -EINVAL;
- if (new_timeout > MAX_TIMEOUT)
- return -EINVAL;
- rc32434_wdt_set(new_timeout);
+ /* Fall through */
case WDIOC_GETTIMEOUT:
return copy_to_user(argp, &timeout, sizeof(int));
default:
return 0;
}
-static struct file_operations rc32434_wdt_fops = {
+static const struct file_operations rc32434_wdt_fops = {
.owner = THIS_MODULE,
.llseek = no_llseek,
.write = rc32434_wdt_write,
.fops = &rc32434_wdt_fops,
};
-static char banner[] = KERN_INFO KBUILD_MODNAME
- ": Watchdog Timer version " VERSION ", timer margin: %d sec\n";
+static char banner[] __devinitdata = KERN_INFO PFX
+ "Watchdog Timer version " VERSION ", timer margin: %d sec\n";
-static int rc32434_wdt_probe(struct platform_device *pdev)
+static int __devinit rc32434_wdt_probe(struct platform_device *pdev)
{
int ret;
struct resource *r;
- r = platform_get_resource_byname(pdev, IORESOURCE_MEM, "rb500_wdt_res");
+ r = platform_get_resource_byname(pdev, IORESOURCE_MEM, "rb532_wdt_res");
if (!r) {
- printk(KERN_ERR KBUILD_MODNAME
- "failed to retrieve resources\n");
+ printk(KERN_ERR PFX "failed to retrieve resources\n");
return -ENODEV;
}
wdt_reg = ioremap_nocache(r->start, r->end - r->start);
if (!wdt_reg) {
- printk(KERN_ERR KBUILD_MODNAME
- "failed to remap I/O resources\n");
+ printk(KERN_ERR PFX "failed to remap I/O resources\n");
return -ENXIO;
}
- ret = misc_register(&rc32434_wdt_miscdev);
+ spin_lock_init(&rc32434_wdt_device.io_lock);
+
+ /* Make sure the watchdog is not running */
+ rc32434_wdt_stop();
+
+ /* Check that the heartbeat value is within it's range;
+ * if not reset to the default */
+ if (rc32434_wdt_set(timeout)) {
+ rc32434_wdt_set(WATCHDOG_TIMEOUT);
+ printk(KERN_INFO PFX
+ "timeout value must be between 0 and %d\n",
+ WTCOMP2SEC((u32)-1));
+ }
+ ret = misc_register(&rc32434_wdt_miscdev);
if (ret < 0) {
- printk(KERN_ERR KBUILD_MODNAME
- "failed to register watchdog device\n");
+ printk(KERN_ERR PFX "failed to register watchdog device\n");
goto unmap;
}
- init_completion(&rc32434_wdt_device.stop);
- rc32434_wdt_device.queue = 0;
-
- clear_bit(0, &rc32434_wdt_device.inuse);
-
- setup_timer(&rc32434_wdt_device.timer, rc32434_wdt_update, 0L);
-
- rc32434_wdt_device.default_ticks = ticks;
-
- rc32434_wdt_start();
-
printk(banner, timeout);
return 0;
return ret;
}
-static int rc32434_wdt_remove(struct platform_device *pdev)
+static int __devexit rc32434_wdt_remove(struct platform_device *pdev)
{
- if (rc32434_wdt_device.queue) {
- rc32434_wdt_device.queue = 0;
- wait_for_completion(&rc32434_wdt_device.stop);
- }
misc_deregister(&rc32434_wdt_miscdev);
-
iounmap(wdt_reg);
-
return 0;
}
-static struct platform_driver rc32434_wdt = {
- .probe = rc32434_wdt_probe,
- .remove = rc32434_wdt_remove,
- .driver = {
- .name = "rc32434_wdt",
+static void rc32434_wdt_shutdown(struct platform_device *pdev)
+{
+ rc32434_wdt_stop();
+}
+
+static struct platform_driver rc32434_wdt_driver = {
+ .probe = rc32434_wdt_probe,
+ .remove = __devexit_p(rc32434_wdt_remove),
+ .shutdown = rc32434_wdt_shutdown,
+ .driver = {
+ .name = "rc32434_wdt",
}
};
static int __init rc32434_wdt_init(void)
{
- return platform_driver_register(&rc32434_wdt);
+ return platform_driver_register(&rc32434_wdt_driver);
}
static void __exit rc32434_wdt_exit(void)
{
- platform_driver_unregister(&rc32434_wdt);
+ platform_driver_unregister(&rc32434_wdt_driver);
}
module_init(rc32434_wdt_init);
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff