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path: root/drivers/char/watchdog/advantechwdt.c
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Diffstat (limited to 'drivers/char/watchdog/advantechwdt.c')
-rw-r--r--drivers/char/watchdog/advantechwdt.c333
1 files changed, 333 insertions, 0 deletions
diff --git a/drivers/char/watchdog/advantechwdt.c b/drivers/char/watchdog/advantechwdt.c
new file mode 100644
index 000000000000..ea73c8379bdd
--- /dev/null
+++ b/drivers/char/watchdog/advantechwdt.c
@@ -0,0 +1,333 @@
+/*
+ * Advantech Single Board Computer WDT driver
+ *
+ * (c) Copyright 2000-2001 Marek Michalkiewicz <marekm@linux.org.pl>
+ *
+ * Based on acquirewdt.c which is based on wdt.c.
+ * Original copyright messages:
+ *
+ * (c) Copyright 1996 Alan Cox <alan@redhat.com>, All Rights Reserved.
+ * http://www.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 Alan Cox nor CymruNet Ltd. admit liability nor provide
+ * warranty for any of this software. This material is provided
+ * "AS-IS" and at no charge.
+ *
+ * (c) Copyright 1995 Alan Cox <alan@redhat.com>
+ *
+ * 14-Dec-2001 Matt Domsch <Matt_Domsch@dell.com>
+ * Added nowayout module option to override CONFIG_WATCHDOG_NOWAYOUT
+ *
+ * 16-Oct-2002 Rob Radez <rob@osinvestor.com>
+ * Clean up ioctls, clean up init + exit, add expect close support,
+ * add wdt_start and wdt_stop as parameters.
+ */
+
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/types.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 <asm/io.h>
+#include <asm/uaccess.h>
+#include <asm/system.h>
+
+#define WATCHDOG_NAME "Advantech WDT"
+#define PFX WATCHDOG_NAME ": "
+#define WATCHDOG_TIMEOUT 60 /* 60 sec default timeout */
+
+static unsigned long advwdt_is_open;
+static char adv_expect_close;
+
+/*
+ * You must set these - there is no sane way to probe for this board.
+ *
+ * To enable or restart, write the timeout value in seconds (1 to 63)
+ * to I/O port wdt_start. To disable, read I/O port wdt_stop.
+ * Both are 0x443 for most boards (tested on a PCA-6276VE-00B1), but
+ * check your manual (at least the PCA-6159 seems to be different -
+ * the manual says wdt_stop is 0x43, not 0x443).
+ * (0x43 is also a write-only control register for the 8254 timer!)
+ */
+
+static int wdt_stop = 0x443;
+module_param(wdt_stop, int, 0);
+MODULE_PARM_DESC(wdt_stop, "Advantech WDT 'stop' io port (default 0x443)");
+
+static int wdt_start = 0x443;
+module_param(wdt_start, int, 0);
+MODULE_PARM_DESC(wdt_start, "Advantech WDT 'start' io port (default 0x443)");
+
+static int timeout = WATCHDOG_TIMEOUT; /* in seconds */
+module_param(timeout, int, 0);
+MODULE_PARM_DESC(timeout, "Watchdog timeout in seconds. 1<= timeout <=63, default=" __MODULE_STRING(WATCHDOG_TIMEOUT) ".");
+
+#ifdef CONFIG_WATCHDOG_NOWAYOUT
+static int nowayout = 1;
+#else
+static int nowayout = 0;
+#endif
+
+module_param(nowayout, int, 0);
+MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=CONFIG_WATCHDOG_NOWAYOUT)");
+
+/*
+ * Kernel methods.
+ */
+
+static void
+advwdt_ping(void)
+{
+ /* Write a watchdog value */
+ outb_p(timeout, wdt_start);
+}
+
+static void
+advwdt_disable(void)
+{
+ inb_p(wdt_stop);
+}
+
+static ssize_t
+advwdt_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos)
+{
+ if (count) {
+ if (!nowayout) {
+ size_t i;
+
+ adv_expect_close = 0;
+
+ for (i = 0; i != count; i++) {
+ char c;
+ if (get_user(c, buf+i))
+ return -EFAULT;
+ if (c == 'V')
+ adv_expect_close = 42;
+ }
+ }
+ advwdt_ping();
+ }
+ return count;
+}
+
+static int
+advwdt_ioctl(struct inode *inode, struct file *file, unsigned int cmd,
+ unsigned long arg)
+{
+ int new_timeout;
+ void __user *argp = (void __user *)arg;
+ int __user *p = argp;
+ static struct watchdog_info ident = {
+ .options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE,
+ .firmware_version = 1,
+ .identity = "Advantech WDT",
+ };
+
+ switch (cmd) {
+ case WDIOC_GETSUPPORT:
+ if (copy_to_user(argp, &ident, sizeof(ident)))
+ return -EFAULT;
+ break;
+
+ case WDIOC_GETSTATUS:
+ case WDIOC_GETBOOTSTATUS:
+ return put_user(0, p);
+
+ case WDIOC_KEEPALIVE:
+ advwdt_ping();
+ break;
+
+ case WDIOC_SETTIMEOUT:
+ if (get_user(new_timeout, p))
+ return -EFAULT;
+ if ((new_timeout < 1) || (new_timeout > 63))
+ return -EINVAL;
+ timeout = new_timeout;
+ advwdt_ping();
+ /* Fall */
+
+ case WDIOC_GETTIMEOUT:
+ return put_user(timeout, p);
+
+ case WDIOC_SETOPTIONS:
+ {
+ int options, retval = -EINVAL;
+
+ if (get_user(options, p))
+ return -EFAULT;
+
+ if (options & WDIOS_DISABLECARD) {
+ advwdt_disable();
+ retval = 0;
+ }
+
+ if (options & WDIOS_ENABLECARD) {
+ advwdt_ping();
+ retval = 0;
+ }
+
+ return retval;
+ }
+
+ default:
+ return -ENOIOCTLCMD;
+ }
+ return 0;
+}
+
+static int
+advwdt_open(struct inode *inode, struct file *file)
+{
+ if (test_and_set_bit(0, &advwdt_is_open))
+ return -EBUSY;
+ /*
+ * Activate
+ */
+
+ advwdt_ping();
+ return nonseekable_open(inode, file);
+}
+
+static int
+advwdt_close(struct inode *inode, struct file *file)
+{
+ if (adv_expect_close == 42) {
+ advwdt_disable();
+ } else {
+ printk(KERN_CRIT PFX "Unexpected close, not stopping watchdog!\n");
+ advwdt_ping();
+ }
+ clear_bit(0, &advwdt_is_open);
+ adv_expect_close = 0;
+ return 0;
+}
+
+/*
+ * Notifier for system down
+ */
+
+static int
+advwdt_notify_sys(struct notifier_block *this, unsigned long code,
+ void *unused)
+{
+ if (code == SYS_DOWN || code == SYS_HALT) {
+ /* Turn the WDT off */
+ advwdt_disable();
+ }
+ return NOTIFY_DONE;
+}
+
+/*
+ * Kernel Interfaces
+ */
+
+static struct file_operations advwdt_fops = {
+ .owner = THIS_MODULE,
+ .llseek = no_llseek,
+ .write = advwdt_write,
+ .ioctl = advwdt_ioctl,
+ .open = advwdt_open,
+ .release = advwdt_close,
+};
+
+static struct miscdevice advwdt_miscdev = {
+ .minor = WATCHDOG_MINOR,
+ .name = "watchdog",
+ .fops = &advwdt_fops,
+};
+
+/*
+ * The WDT needs to learn about soft shutdowns in order to
+ * turn the timebomb registers off.
+ */
+
+static struct notifier_block advwdt_notifier = {
+ .notifier_call = advwdt_notify_sys,
+};
+
+static int __init
+advwdt_init(void)
+{
+ int ret;
+
+ printk(KERN_INFO "WDT driver for Advantech single board computer initialising.\n");
+
+ if (timeout < 1 || timeout > 63) {
+ timeout = WATCHDOG_TIMEOUT;
+ printk (KERN_INFO PFX "timeout value must be 1<=x<=63, using %d\n",
+ timeout);
+ }
+
+ if (wdt_stop != wdt_start) {
+ if (!request_region(wdt_stop, 1, WATCHDOG_NAME)) {
+ printk (KERN_ERR PFX "I/O address 0x%04x already in use\n",
+ wdt_stop);
+ ret = -EIO;
+ goto out;
+ }
+ }
+
+ if (!request_region(wdt_start, 1, WATCHDOG_NAME)) {
+ printk (KERN_ERR PFX "I/O address 0x%04x already in use\n",
+ wdt_start);
+ ret = -EIO;
+ goto unreg_stop;
+ }
+
+ ret = register_reboot_notifier(&advwdt_notifier);
+ if (ret != 0) {
+ printk (KERN_ERR PFX "cannot register reboot notifier (err=%d)\n",
+ ret);
+ goto unreg_regions;
+ }
+
+ ret = misc_register(&advwdt_miscdev);
+ if (ret != 0) {
+ printk (KERN_ERR PFX "cannot register miscdev on minor=%d (err=%d)\n",
+ WATCHDOG_MINOR, ret);
+ goto unreg_reboot;
+ }
+
+ printk (KERN_INFO PFX "initialized. timeout=%d sec (nowayout=%d)\n",
+ timeout, nowayout);
+
+out:
+ return ret;
+unreg_reboot:
+ unregister_reboot_notifier(&advwdt_notifier);
+unreg_regions:
+ release_region(wdt_start, 1);
+unreg_stop:
+ if (wdt_stop != wdt_start)
+ release_region(wdt_stop, 1);
+ goto out;
+}
+
+static void __exit
+advwdt_exit(void)
+{
+ misc_deregister(&advwdt_miscdev);
+ unregister_reboot_notifier(&advwdt_notifier);
+ if(wdt_stop != wdt_start)
+ release_region(wdt_stop,1);
+ release_region(wdt_start,1);
+}
+
+module_init(advwdt_init);
+module_exit(advwdt_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Marek Michalkiewicz <marekm@linux.org.pl>");
+MODULE_DESCRIPTION("Advantech Single Board Computer WDT driver");
+MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);