Initial import

1 files changed, 408 insertions, 0 deletions

diff --git a/drivers/watchdog/w83877f_wdt.c b/drivers/watchdog/w83877f_wdt.c
new file mode 100644
index 000000000..f0483c75e
--- /dev/null
+++ b/drivers/watchdog/w83877f_wdt.c
@@ -0,0 +1,408 @@
+/*
+ *	W83877F Computer Watchdog Timer driver
+ *
+ *      Based on acquirewdt.c by Alan Cox,
+ *           and sbc60xxwdt.c by Jakob Oestergaard <jakob@unthought.net>
+ *
+ *	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.
+ *
+ *	The authors do NOT admit liability nor provide warranty for
+ *	any of this software. This material is provided "AS-IS" in
+ *      the hope that it may be useful for others.
+ *
+ *	(c) Copyright 2001    Scott Jennings <linuxdrivers@oro.net>
+ *
+ *           4/19 - 2001      [Initial revision]
+ *           9/27 - 2001      Added spinlocking
+ *           4/12 - 2002      [rob@osinvestor.com] Eliminate extra comments
+ *                            Eliminate fop_read
+ *                            Eliminate extra spin_unlock
+ *                            Added KERN_* tags to printks
+ *                            add CONFIG_WATCHDOG_NOWAYOUT support
+ *                            fix possible wdt_is_open race
+ *                            changed watchdog_info to correctly reflect what
+ *			      the driver offers
+ *                            added WDIOC_GETSTATUS, WDIOC_GETBOOTSTATUS,
+ *			      WDIOC_SETTIMEOUT,
+ *                            WDIOC_GETTIMEOUT, and WDIOC_SETOPTIONS ioctls
+ *           09/8 - 2003      [wim@iguana.be] cleanup of trailing spaces
+ *                            added extra printk's for startup problems
+ *                            use module_param
+ *                            made timeout (the emulated heartbeat) a
+ *			      module_param
+ *                            made the keepalive ping an internal subroutine
+ *
+ *  This WDT driver is different from most other Linux WDT
+ *  drivers in that the driver will ping the watchdog by itself,
+ *  because this particular WDT has a very short timeout (1.6
+ *  seconds) and it would be insane to count on any userspace
+ *  daemon always getting scheduled within that time frame.
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/types.h>
+#include <linux/timer.h>
+#include <linux/jiffies.h>
+#include <linux/miscdevice.h>
+#include <linux/watchdog.h>
+#include <linux/fs.h>
+#include <linux/ioport.h>
+#include <linux/notifier.h>
+#include <linux/reboot.h>
+#include <linux/init.h>
+#include <linux/io.h>
+#include <linux/uaccess.h>
+
+#define OUR_NAME "w83877f_wdt"
+
+#define ENABLE_W83877F_PORT 0x3F0
+#define ENABLE_W83877F 0x87
+#define DISABLE_W83877F 0xAA
+#define WDT_PING 0x443
+#define WDT_REGISTER 0x14
+#define WDT_ENABLE 0x9C
+#define WDT_DISABLE 0x8C
+
+/*
+ * The W83877F seems to be fixed at 1.6s timeout (at least on the
+ * EMACS PC-104 board I'm using). If we reset the watchdog every
+ * ~250ms we should be safe.  */
+
+#define WDT_INTERVAL (HZ/4+1)
+
+/*
+ * We must not require too good response from the userspace daemon.
+ * Here we require the userspace daemon to send us a heartbeat
+ * char to /dev/watchdog every 30 seconds.
+ */
+
+#define WATCHDOG_TIMEOUT 30            /* 30 sec default timeout */
+/* in seconds, will be multiplied by HZ to get seconds to wait for a ping */
+static int timeout = WATCHDOG_TIMEOUT;
+module_param(timeout, int, 0);
+MODULE_PARM_DESC(timeout,
+	"Watchdog timeout in seconds. (1<=timeout<=3600, default="
+				__MODULE_STRING(WATCHDOG_TIMEOUT) ")");
+
+
+static bool nowayout = WATCHDOG_NOWAYOUT;
+module_param(nowayout, bool, 0);
+MODULE_PARM_DESC(nowayout,
+		"Watchdog cannot be stopped once started (default="
+				__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
+
+static void wdt_timer_ping(unsigned long);
+static DEFINE_TIMER(timer, wdt_timer_ping, 0, 0);
+static unsigned long next_heartbeat;
+static unsigned long wdt_is_open;
+static char wdt_expect_close;
+static DEFINE_SPINLOCK(wdt_spinlock);
+
+/*
+ *	Whack the dog
+ */
+
+static void wdt_timer_ping(unsigned long data)
+{
+	/* If we got a heartbeat pulse within the WDT_US_INTERVAL
+	 * we agree to ping the WDT
+	 */
+	if (time_before(jiffies, next_heartbeat)) {
+		/* Ping the WDT */
+		spin_lock(&wdt_spinlock);
+
+		/* Ping the WDT by reading from WDT_PING */
+		inb_p(WDT_PING);
+
+		/* Re-set the timer interval */
+		mod_timer(&timer, jiffies + WDT_INTERVAL);
+
+		spin_unlock(&wdt_spinlock);
+
+	} else
+		pr_warn("Heartbeat lost! Will not ping the watchdog\n");
+}
+
+/*
+ * Utility routines
+ */
+
+static void wdt_change(int writeval)
+{
+	unsigned long flags;
+	spin_lock_irqsave(&wdt_spinlock, flags);
+
+	/* buy some time */
+	inb_p(WDT_PING);
+
+	/* make W83877F available */
+	outb_p(ENABLE_W83877F,  ENABLE_W83877F_PORT);
+	outb_p(ENABLE_W83877F,  ENABLE_W83877F_PORT);
+
+	/* enable watchdog */
+	outb_p(WDT_REGISTER,    ENABLE_W83877F_PORT);
+	outb_p(writeval,        ENABLE_W83877F_PORT+1);
+
+	/* lock the W8387FF away */
+	outb_p(DISABLE_W83877F, ENABLE_W83877F_PORT);
+
+	spin_unlock_irqrestore(&wdt_spinlock, flags);
+}
+
+static void wdt_startup(void)
+{
+	next_heartbeat = jiffies + (timeout * HZ);
+
+	/* Start the timer */
+	mod_timer(&timer, jiffies + WDT_INTERVAL);
+
+	wdt_change(WDT_ENABLE);
+
+	pr_info("Watchdog timer is now enabled\n");
+}
+
+static void wdt_turnoff(void)
+{
+	/* Stop the timer */
+	del_timer(&timer);
+
+	wdt_change(WDT_DISABLE);
+
+	pr_info("Watchdog timer is now disabled...\n");
+}
+
+static void wdt_keepalive(void)
+{
+	/* user land ping */
+	next_heartbeat = jiffies + (timeout * HZ);
+}
+
+/*
+ * /dev/watchdog handling
+ */
+
+static ssize_t fop_write(struct file *file, const char __user *buf,
+						size_t count, loff_t *ppos)
+{
+	/* See if we got the magic character 'V' and reload the timer */
+	if (count) {
+		if (!nowayout) {
+			size_t ofs;
+
+			/* note: just in case someone wrote the magic
+			   character five months ago... */
+			wdt_expect_close = 0;
+
+			/* scan to see whether or not we got the
+			   magic character */
+			for (ofs = 0; ofs != count; ofs++) {
+				char c;
+				if (get_user(c, buf + ofs))
+					return -EFAULT;
+				if (c == 'V')
+					wdt_expect_close = 42;
+			}
+		}
+
+		/* someone wrote to us, we should restart timer */
+		wdt_keepalive();
+	}
+	return count;
+}
+
+static int fop_open(struct inode *inode, struct file *file)
+{
+	/* Just in case we're already talking to someone... */
+	if (test_and_set_bit(0, &wdt_is_open))
+		return -EBUSY;
+
+	/* Good, fire up the show */
+	wdt_startup();
+	return nonseekable_open(inode, file);
+}
+
+static int fop_close(struct inode *inode, struct file *file)
+{
+	if (wdt_expect_close == 42)
+		wdt_turnoff();
+	else {
+		del_timer(&timer);
+		pr_crit("device file closed unexpectedly. Will not stop the WDT!\n");
+	}
+	clear_bit(0, &wdt_is_open);
+	wdt_expect_close = 0;
+	return 0;
+}
+
+static long fop_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
+{
+	void __user *argp = (void __user *)arg;
+	int __user *p = argp;
+	static const struct watchdog_info ident = {
+		.options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT
+							| WDIOF_MAGICCLOSE,
+		.firmware_version = 1,
+		.identity = "W83877F",
+	};
+
+	switch (cmd) {
+	case WDIOC_GETSUPPORT:
+		return copy_to_user(argp, &ident, sizeof(ident)) ? -EFAULT : 0;
+	case WDIOC_GETSTATUS:
+	case WDIOC_GETBOOTSTATUS:
+		return put_user(0, p);
+	case WDIOC_SETOPTIONS:
+	{
+		int new_options, retval = -EINVAL;
+
+		if (get_user(new_options, p))
+			return -EFAULT;
+
+		if (new_options & WDIOS_DISABLECARD) {
+			wdt_turnoff();
+			retval = 0;
+		}
+
+		if (new_options & WDIOS_ENABLECARD) {
+			wdt_startup();
+			retval = 0;
+		}
+
+		return retval;
+	}
+	case WDIOC_KEEPALIVE:
+		wdt_keepalive();
+		return 0;
+	case WDIOC_SETTIMEOUT:
+	{
+		int new_timeout;
+
+		if (get_user(new_timeout, p))
+			return -EFAULT;
+
+		/* arbitrary upper limit */
+		if (new_timeout < 1 || new_timeout > 3600)
+			return -EINVAL;
+
+		timeout = new_timeout;
+		wdt_keepalive();
+		/* Fall through */
+	}
+	case WDIOC_GETTIMEOUT:
+		return put_user(timeout, p);
+	default:
+		return -ENOTTY;
+	}
+}
+
+static const struct file_operations wdt_fops = {
+	.owner		= THIS_MODULE,
+	.llseek		= no_llseek,
+	.write		= fop_write,
+	.open		= fop_open,
+	.release	= fop_close,
+	.unlocked_ioctl	= fop_ioctl,
+};
+
+static struct miscdevice wdt_miscdev = {
+	.minor	= WATCHDOG_MINOR,
+	.name	= "watchdog",
+	.fops	= &wdt_fops,
+};
+
+/*
+ *	Notifier for system down
+ */
+
+static int wdt_notify_sys(struct notifier_block *this, unsigned long code,
+	void *unused)
+{
+	if (code == SYS_DOWN || code == SYS_HALT)
+		wdt_turnoff();
+	return NOTIFY_DONE;
+}
+
+/*
+ *	The WDT needs to learn about soft shutdowns in order to
+ *	turn the timebomb registers off.
+ */
+
+static struct notifier_block wdt_notifier = {
+	.notifier_call = wdt_notify_sys,
+};
+
+static void __exit w83877f_wdt_unload(void)
+{
+	wdt_turnoff();
+
+	/* Deregister */
+	misc_deregister(&wdt_miscdev);
+
+	unregister_reboot_notifier(&wdt_notifier);
+	release_region(WDT_PING, 1);
+	release_region(ENABLE_W83877F_PORT, 2);
+}
+
+static int __init w83877f_wdt_init(void)
+{
+	int rc = -EBUSY;
+
+	if (timeout < 1 || timeout > 3600) { /* arbitrary upper limit */
+		timeout = WATCHDOG_TIMEOUT;
+		pr_info("timeout value must be 1 <= x <= 3600, using %d\n",
+			timeout);
+	}
+
+	if (!request_region(ENABLE_W83877F_PORT, 2, "W83877F WDT")) {
+		pr_err("I/O address 0x%04x already in use\n",
+		       ENABLE_W83877F_PORT);
+		rc = -EIO;
+		goto err_out;
+	}
+
+	if (!request_region(WDT_PING, 1, "W8387FF WDT")) {
+		pr_err("I/O address 0x%04x already in use\n", WDT_PING);
+		rc = -EIO;
+		goto err_out_region1;
+	}
+
+	rc = register_reboot_notifier(&wdt_notifier);
+	if (rc) {
+		pr_err("cannot register reboot notifier (err=%d)\n", rc);
+		goto err_out_region2;
+	}
+
+	rc = misc_register(&wdt_miscdev);
+	if (rc) {
+		pr_err("cannot register miscdev on minor=%d (err=%d)\n",
+		       wdt_miscdev.minor, rc);
+		goto err_out_reboot;
+	}
+
+	pr_info("WDT driver for W83877F initialised. timeout=%d sec (nowayout=%d)\n",
+		timeout, nowayout);
+
+	return 0;
+
+err_out_reboot:
+	unregister_reboot_notifier(&wdt_notifier);
+err_out_region2:
+	release_region(WDT_PING, 1);
+err_out_region1:
+	release_region(ENABLE_W83877F_PORT, 2);
+err_out:
+	return rc;
+}
+
+module_init(w83877f_wdt_init);
+module_exit(w83877f_wdt_unload);
+
+MODULE_AUTHOR("Scott and Bill Jennings");
+MODULE_DESCRIPTION("Driver for watchdog timer in w83877f chip");
+MODULE_LICENSE("GPL");