[WATCHDOG] MTX-1 Watchdog driver

This patch adds support for the MTX-1 boards watchdog. If not available the
board will reboot every 100 seconds. It uses the Linux watchdog and timer
APIs.
Signed-off-by: Florian Fainelli <florian.fainelli@int-evry.fr>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>

drivers/char/watchdog/Kconfig

@@ -551,6 +551,13 @@ config INDYDOG
 	  timer expired and no process has written to /dev/watchdog during
 	  that time.
 
+config WDT_MTX1
+	tristate "MTX-1 Hardware Watchdog"
+	depends on MIPS_MTX1
+	help
+	  Hardware driver for the MTX-1 boards. This is a watchdog timer that
+	  will reboot the machine after a 100 seconds timer expired.
+
 config WDT_RM9K_GPI
 	tristate "RM9000/GPI hardware watchdog"
 	depends on CPU_RM9000

drivers/char/watchdog/Makefile

@@ -72,6 +72,7 @@ obj-$(CONFIG_WATCHDOG_RTAS) += wdrtas.o
 
 # MIPS Architecture
 obj-$(CONFIG_INDYDOG) += indydog.o
+obj-$(CONFIG_WDT_MTX1)	+= mtx-1_wdt.o
 obj-$(CONFIG_WDT_RM9K_GPI) += rm9k_wdt.o
 
 # S390 Architecture

drivers/char/watchdog/mtx-1_wdt.c

+/*
+ *      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");