[ARM] Add support for the StrongARM-11x0 watchdog.

Add sa1100_wdt watchdog support.

drivers/char/watchdog/Kconfig

@@ -168,6 +168,19 @@ config 977_WATCHDOG
 
 	  Not sure? It's safe to say N.
 
+config SA1100_WATCHDOG
+	tristate "SA1100 watchdog"
+	depends on WATCHDOG && ARCH_SA1100
+	help
+	  Watchdog timer embedded into SA11x0 chips. This will reboot your
+	  system when timeout is reached.
+	  NOTE, that once enabled, this timer cannot be disabled.
+
+	  This driver is also available as a module ( = code which can be
+	  inserted in and removed from the running kernel whenever you want).
+	  If you want to compile it as a module, say M here and read
+	  Documentation/modules.txt. The module will be called sa1100_wdt.o.
+
 config EUROTECH_WDT
 	tristate "Eurotech CPU-1220/1410 Watchdog Timer"
 	depends on WATCHDOG

drivers/char/watchdog/Makefile

@@ -21,5 +21,6 @@ obj-$(CONFIG_977_WATCHDOG) += wdt977.o
 obj-$(CONFIG_I810_TCO) += i810-tco.o
 obj-$(CONFIG_MACHZ_WDT) += machzwd.o
 obj-$(CONFIG_SH_WDT) += shwdt.o
+obj-$(CONFIG_SA1100_WATCHDOG) += sa1100_wdt.o
 obj-$(CONFIG_EUROTECH_WDT) += eurotechwdt.o
 obj-$(CONFIG_SOFT_WATCHDOG) += softdog.o

drivers/char/watchdog/sa1100_wdt.c

+/*
+ *	Watchdog driver for the SA11x0
+ *
+ *      (c) Copyright 2000 Oleg Drokin <green@crimea.edu>
+ *          Based on SoftDog driver by Alan Cox <alan@redhat.com>
+ *
+ *	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.
+ *
+ *	Neither Oleg Drokin nor iXcelerator.com admit liability nor provide
+ *	warranty for any of this software. This material is provided
+ *	"AS-IS" and at no charge.
+ *
+ *	(c) Copyright 2000           Oleg Drokin <green@crimea.edu>
+ *
+ *      27/11/2000 Initial release
+ */
+#include <linux/config.h>
+#include <linux/module.h>
+#include <linux/types.h>
+#include <linux/kernel.h>
+#include <linux/fs.h>
+#include <linux/miscdevice.h>
+#include <linux/watchdog.h>
+#include <linux/smp_lock.h>
+#include <linux/init.h>
+
+#include <asm/hardware.h>
+#include <asm/bitops.h>
+#include <asm/uaccess.h>
+
+#define OSCR_FREQ		3686400
+#define SA1100_CLOSE_MAGIC	(0x5afc4453)
+
+static unsigned long sa1100wdt_users;
+static int expect_close;
+static int pre_margin;
+static int boot_status;
+#ifdef CONFIG_WATCHDOG_NOWAYOUT
+static int nowayout = 1;
+#else
+static int nowayout = 0;
+#endif
+
+/*
+ *	Allow only one person to hold it open
+ */
+static int sa1100dog_open(struct inode *inode, struct file *file)
+{
+	if (test_and_set_bit(1,&sa1100wdt_users))
+		return -EBUSY;
+
+	/* Activate SA1100 Watchdog timer */
+	OSMR3 = OSCR + pre_margin;
+	OSSR = OSSR_M3;
+	OWER = OWER_WME;
+	OIER |= OIER_E3;
+	return 0;
+}
+
+/*
+ *	Shut off the timer.
+ * 	Lock it in if it's a module and we defined ...NOWAYOUT
+ *	Oddly, the watchdog can only be enabled, but we can turn off
+ *	the interrupt, which appears to prevent the watchdog timing out.
+ */
+static int sa1100dog_release(struct inode *inode, struct file *file)
+{
+	OSMR3 = OSCR + pre_margin;
+
+	if (expect_close == SA1100_CLOSE_MAGIC) {
+		OIER &= ~OIER_E3;
+	} else {
+		printk(KERN_CRIT "WATCHDOG: WDT device closed unexpectedly.  WDT will not stop!\n");
+	}
+
+	clear_bit(1, &sa1100wdt_users);
+
+	return 0;
+}
+
+static ssize_t sa1100dog_write(struct file *file, const char *data, size_t len, loff_t *ppos)
+{
+	/* Can't seek (pwrite) on this device  */
+	if (ppos != &file->f_pos)
+		return -ESPIPE;
+
+	if (len) {
+		if (!nowayout) {
+			size_t i;
+
+			expect_close = 0;
+
+			for (i = 0; i != len; i++) {
+				char c;
+
+				if (get_user(c, data + i))
+					return -EFAULT;
+				if (c == 'V')
+					expect_close = SA1100_CLOSE_MAGIC;
+			}
+		}
+		/* Refresh OSMR3 timer. */
+		OSMR3 = OSCR + pre_margin;
+	}
+
+	return len ? 1 : 0;
+}
+
+static struct watchdog_info ident = {
+	.options	= WDIOF_CARDRESET | WDIOF_MAGICCLOSE |
+			  WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING,
+	.identity	= "SA1100 Watchdog",
+};
+
+static int sa1100dog_ioctl(struct inode *inode, struct file *file,
+	unsigned int cmd, unsigned long arg)
+{
+	int ret = -ENOIOCTLCMD;
+	int time;
+
+	switch (cmd) {
+	case WDIOC_GETSUPPORT:
+		ret = copy_to_user((struct watchdog_info *)arg, &ident,
+				   sizeof(ident)) ? -EFAULT : 0;
+		break;
+
+	case WDIOC_GETSTATUS:
+		ret = put_user(0, (int *)arg);
+		break;
+
+	case WDIOC_GETBOOTSTATUS:
+		ret = put_user(boot_status, (int *)arg);
+		break;
+
+	case WDIOC_SETTIMEOUT:
+		ret = get_user(time, (int *)arg);
+		if (ret)
+			break;
+
+		if (time <= 0 || time > 255) {
+			ret = -EINVAL;
+			break;
+		}
+
+		pre_margin = OSCR_FREQ * time;
+		OSMR3 = OSCR + pre_margin;
+		/*fall through*/
+
+	case WDIOC_GETTIMEOUT:
+		ret = put_user(pre_margin / OSCR_FREQ, (int *)arg);
+		break;
+
+	case WDIOC_KEEPALIVE:
+		OSMR3 = OSCR + pre_margin;
+		ret = 0;
+		break;
+	}
+	return ret;
+}
+
+static struct file_operations sa1100dog_fops =
+{
+	.owner		= THIS_MODULE,
+	.write		= sa1100dog_write,
+	.ioctl		= sa1100dog_ioctl,
+	.open		= sa1100dog_open,
+	.release	= sa1100dog_release,
+};
+
+static struct miscdevice sa1100dog_miscdev =
+{
+	.minor		= WATCHDOG_MINOR,
+	.name		= "SA1100 watchdog",
+	.fops		= &sa1100dog_fops,
+};
+
+static int margin __initdata = 60;		/* (secs) Default is 1 minute */
+
+static int __init sa1100dog_init(void)
+{
+	int ret;
+
+	/*
+	 * Read the reset status, and save it for later.  If
+	 * we suspend, RCSR will be cleared, and the watchdog
+	 * reset reason will be lost.
+	 */
+	boot_status = (RCSR & RCSR_WDR) ? WDIOF_CARDRESET : 0;
+	pre_margin = OSCR_FREQ * margin;
+
+	ret = misc_register(&sa1100dog_miscdev);
+	if (ret == 0)
+		printk("SA1100 Watchdog Timer: timer margin %d sec\n",
+		       margin);
+
+	return ret;
+}
+
+static void __exit sa1100dog_exit(void)
+{
+	misc_deregister(&sa1100dog_miscdev);
+}
+
+module_init(sa1100dog_init);
+module_exit(sa1100dog_exit);
+
+MODULE_AUTHOR("Oleg Drokin <green@crimea.edu>");
+MODULE_DESCRIPTION("SA1100 Watchdog");
+MODULE_PARM(margin,"i");
+MODULE_PARM_DESC(margin, "Watchdog margin in seconds (default 60s)");
+
+MODULE_PARM(nowayout, "i");
+MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started");
+MODULE_LICENSE("GPL");