--- /dev/null
+/*
+ * Driver for the MTX-1 Watchdog.
+ *
+ * (C) Copyright 2005 4G Systems <info@4g-systems.biz>, All Rights Reserved.
+ * http://www.4g-systems.biz
+ *
+ * (C) Copyright 2007 OpenWrt.org, Florian Fainelli <florian@openwrt.org>
+ *
+ * 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 Michael Stickel nor 4G Systems admit liability nor provide
+ * warranty for any of this software. This material is provided
+ * "AS-IS" and at no charge.
+ *
+ * (c) Copyright 2005 4G Systems <info@4g-systems.biz>
+ *
+ * Release 0.01.
+ * Author: Michael Stickel michael.stickel@4g-systems.biz
+ *
+ * Release 0.02.
+ * Author: Florian Fainelli florian@openwrt.org
+ * use the Linux watchdog/timer APIs
+ *
+ * The Watchdog is configured to reset the MTX-1
+ * if it is not triggered for 100 seconds.
+ * It should not be triggered more often than 1.6 seconds.
+ *
+ * A timer triggers the watchdog every 5 seconds, until
+ * it is opened for the first time. After the first open
+ * it MUST be triggered every 2..95 seconds.
+ */
+
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/types.h>
+#include <linux/errno.h>
+#include <linux/miscdevice.h>
+#include <linux/fs.h>
+#include <linux/init.h>
+#include <linux/ioport.h>
+#include <linux/timer.h>
+#include <linux/completion.h>
+#include <linux/jiffies.h>
+#include <linux/watchdog.h>
+#include <asm/io.h>
+#include <asm/uaccess.h>
+
+#include <asm/mach-au1x00/au1000.h>
+
+#define MTX1_WDT_INTERVAL (5 * HZ)
+
+static int ticks = 100 * HZ;
+
+static struct {
+ struct completion stop;
+ volatile int running;
+ struct timer_list timer;
+ volatile int queue;
+ int default_ticks;
+ unsigned long inuse;
+} mtx1_wdt_device;
+
+static void mtx1_wdt_trigger(unsigned long unused)
+{
+ u32 tmp;
+
+ if (mtx1_wdt_device.running)
+ ticks--;
+ /*
+ * toggle GPIO2_15
+ */
+ tmp = au_readl(GPIO2_DIR);
+ tmp = (tmp & ~(1<<15)) | ((~tmp) & (1<<15));
+ au_writel (tmp, GPIO2_DIR);
+
+ if (mtx1_wdt_device.queue && ticks)
+ mod_timer(&mtx1_wdt_device.timer, jiffies + MTX1_WDT_INTERVAL);
+ else {
+ complete(&mtx1_wdt_device.stop);
+ }
+}
+
+static void mtx1_wdt_reset(void)
+{
+ ticks = mtx1_wdt_device.default_ticks;
+}
+
+
+static void mtx1_wdt_start(void)
+{
+ if (!mtx1_wdt_device.queue) {
+ mtx1_wdt_device.queue = 1;
+ au_writel (au_readl(GPIO2_DIR) | (u32)(1<<15), GPIO2_DIR);
+ mod_timer(&mtx1_wdt_device.timer, jiffies + MTX1_WDT_INTERVAL);
+ }
+ mtx1_wdt_device.running++;
+}
+
+static int mtx1_wdt_stop(void)
+{
+ if (mtx1_wdt_device.queue) {
+ mtx1_wdt_device.queue = 0;
+ au_writel (au_readl(GPIO2_DIR) & ~((u32)(1<<15)), GPIO2_DIR);
+ }
+
+ ticks = mtx1_wdt_device.default_ticks;
+
+ return 0;
+}
+
+/* Filesystem functions */
+
+static int mtx1_wdt_open(struct inode *inode, struct file *file)
+{
+ if (test_and_set_bit(0, &mtx1_wdt_device.inuse))
+ return -EBUSY;
+
+ return nonseekable_open(inode, file);
+}
+
+
+static int mtx1_wdt_release(struct inode *inode, struct file *file)
+{
+ clear_bit(0, &mtx1_wdt_device.inuse);
+ return 0;
+}
+
+static int mtx1_wdt_ioctl(struct inode *inode, struct file *file, unsigned int cmd, unsigned long arg)
+{
+ void __user *argp = (void __user *)arg;
+ unsigned int value;
+ static struct watchdog_info ident =
+ {
+ .options = WDIOF_CARDRESET,
+ .identity = "MTX-1 WDT",
+ };
+
+ switch(cmd) {
+ case WDIOC_KEEPALIVE:
+ mtx1_wdt_reset();
+ break;
+ case WDIOC_GETSTATUS:
+ 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;
+ switch(value) {
+ case WDIOS_ENABLECARD:
+ mtx1_wdt_start();
+ break;
+ case WDIOS_DISABLECARD:
+ return mtx1_wdt_stop();
+ default:
+ return -EINVAL;
+ }
+ break;
+ default:
+ return -ENOTTY;
+ }
+ return 0;
+}
+
+
+static ssize_t mtx1_wdt_write(struct file *file, const char *buf, size_t count, loff_t *ppos)
+{
+ if (!count)
+ return -EIO;
+
+ mtx1_wdt_reset();
+ return count;
+}
+
+static struct file_operations mtx1_wdt_fops = {
+ .owner = THIS_MODULE,
+ .llseek = no_llseek,
+ .ioctl = mtx1_wdt_ioctl,
+ .open = mtx1_wdt_open,
+ .write = mtx1_wdt_write,
+ .release = mtx1_wdt_release
+};
+
+
+static struct miscdevice mtx1_wdt_misc = {
+ .minor = WATCHDOG_MINOR,
+ .name = "watchdog",
+ .fops = &mtx1_wdt_fops
+};
+
+
+static int __init mtx1_wdt_init(void)
+{
+ int ret;
+
+ if ((ret = misc_register(&mtx1_wdt_misc)) < 0) {
+ printk(KERN_ERR " mtx-1_wdt : failed to register\n");
+ return ret;
+ }
+
+ init_completion(&mtx1_wdt_device.stop);
+ mtx1_wdt_device.queue = 0;
+
+ clear_bit(0, &mtx1_wdt_device.inuse);
+
+ setup_timer(&mtx1_wdt_device.timer, mtx1_wdt_trigger, 0L);
+
+ mtx1_wdt_device.default_ticks = ticks;
+
+ mtx1_wdt_start();
+
+ printk(KERN_INFO "MTX-1 Watchdog driver\n");
+
+ return 0;
+}
+
+static void __exit mtx1_wdt_exit(void)
+{
+ if (mtx1_wdt_device.queue) {
+ mtx1_wdt_device.queue = 0;
+ wait_for_completion(&mtx1_wdt_device.stop);
+ }
+ misc_deregister(&mtx1_wdt_misc);
+}
+
+module_init(mtx1_wdt_init);
+module_exit(mtx1_wdt_exit);
+
+MODULE_AUTHOR("Michael Stickel, Florian Fainelli");
+MODULE_DESCRIPTION("Driver for the MTX-1 watchdog");
+MODULE_LICENSE("GPL");
projects / linux-2.6 / commitdiff