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path: root/drivers/char/watchdog/ixp2000_wdt.c
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Diffstat (limited to 'drivers/char/watchdog/ixp2000_wdt.c')
-rw-r--r--drivers/char/watchdog/ixp2000_wdt.c219
1 files changed, 219 insertions, 0 deletions
diff --git a/drivers/char/watchdog/ixp2000_wdt.c b/drivers/char/watchdog/ixp2000_wdt.c
new file mode 100644
index 000000000000..ab659d37b4d2
--- /dev/null
+++ b/drivers/char/watchdog/ixp2000_wdt.c
@@ -0,0 +1,219 @@
+/*
+ * drivers/watchdog/ixp2000_wdt.c
+ *
+ * Watchdog driver for Intel IXP2000 network processors
+ *
+ * Adapted from the IXP4xx watchdog driver by Lennert Buytenhek.
+ * The original version carries these notices:
+ *
+ * Author: Deepak Saxena <dsaxena@plexity.net>
+ *
+ * Copyright 2004 (c) MontaVista, Software, Inc.
+ * Based on sa1100 driver, Copyright (C) 2000 Oleg Drokin <green@crimea.edu>
+ *
+ * This file is licensed under the terms of the GNU General Public
+ * License version 2. This program is licensed "as is" without any
+ * warranty of any kind, whether express or implied.
+ */
+
+#include <linux/config.h>
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/types.h>
+#include <linux/kernel.h>
+#include <linux/fs.h>
+#include <linux/miscdevice.h>
+#include <linux/watchdog.h>
+#include <linux/init.h>
+#include <linux/bitops.h>
+
+#include <asm/hardware.h>
+#include <asm/uaccess.h>
+
+#ifdef CONFIG_WATCHDOG_NOWAYOUT
+static int nowayout = 1;
+#else
+static int nowayout = 0;
+#endif
+static unsigned int heartbeat = 60; /* (secs) Default is 1 minute */
+static unsigned long wdt_status;
+
+#define WDT_IN_USE 0
+#define WDT_OK_TO_CLOSE 1
+
+static unsigned long wdt_tick_rate;
+
+static void
+wdt_enable(void)
+{
+ ixp2000_reg_write(IXP2000_RESET0, *(IXP2000_RESET0) | WDT_RESET_ENABLE);
+ ixp2000_reg_write(IXP2000_TWDE, WDT_ENABLE);
+ ixp2000_reg_write(IXP2000_T4_CLD, heartbeat * wdt_tick_rate);
+ ixp2000_reg_write(IXP2000_T4_CTL, TIMER_DIVIDER_256 | TIMER_ENABLE);
+}
+
+static void
+wdt_disable(void)
+{
+ ixp2000_reg_write(IXP2000_T4_CTL, 0);
+}
+
+static void
+wdt_keepalive(void)
+{
+ ixp2000_reg_write(IXP2000_T4_CLD, heartbeat * wdt_tick_rate);
+}
+
+static int
+ixp2000_wdt_open(struct inode *inode, struct file *file)
+{
+ if (test_and_set_bit(WDT_IN_USE, &wdt_status))
+ return -EBUSY;
+
+ clear_bit(WDT_OK_TO_CLOSE, &wdt_status);
+
+ wdt_enable();
+
+ return nonseekable_open(inode, file);
+}
+
+static ssize_t
+ixp2000_wdt_write(struct file *file, const char *data, size_t len, loff_t *ppos)
+{
+ if (len) {
+ if (!nowayout) {
+ size_t i;
+
+ clear_bit(WDT_OK_TO_CLOSE, &wdt_status);
+
+ for (i = 0; i != len; i++) {
+ char c;
+
+ if (get_user(c, data + i))
+ return -EFAULT;
+ if (c == 'V')
+ set_bit(WDT_OK_TO_CLOSE, &wdt_status);
+ }
+ }
+ wdt_keepalive();
+ }
+
+ return len;
+}
+
+
+static struct watchdog_info ident = {
+ .options = WDIOF_MAGICCLOSE | WDIOF_SETTIMEOUT |
+ WDIOF_KEEPALIVEPING,
+ .identity = "IXP2000 Watchdog",
+};
+
+static int
+ixp2000_wdt_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(0, (int *)arg);
+ break;
+
+ case WDIOC_SETTIMEOUT:
+ ret = get_user(time, (int *)arg);
+ if (ret)
+ break;
+
+ if (time <= 0 || time > 60) {
+ ret = -EINVAL;
+ break;
+ }
+
+ heartbeat = time;
+ wdt_keepalive();
+ /* Fall through */
+
+ case WDIOC_GETTIMEOUT:
+ ret = put_user(heartbeat, (int *)arg);
+ break;
+
+ case WDIOC_KEEPALIVE:
+ wdt_enable();
+ ret = 0;
+ break;
+ }
+
+ return ret;
+}
+
+static int
+ixp2000_wdt_release(struct inode *inode, struct file *file)
+{
+ if (test_bit(WDT_OK_TO_CLOSE, &wdt_status)) {
+ wdt_disable();
+ } else {
+ printk(KERN_CRIT "WATCHDOG: Device closed unexpectdly - "
+ "timer will not stop\n");
+ }
+
+ clear_bit(WDT_IN_USE, &wdt_status);
+ clear_bit(WDT_OK_TO_CLOSE, &wdt_status);
+
+ return 0;
+}
+
+
+static struct file_operations ixp2000_wdt_fops =
+{
+ .owner = THIS_MODULE,
+ .llseek = no_llseek,
+ .write = ixp2000_wdt_write,
+ .ioctl = ixp2000_wdt_ioctl,
+ .open = ixp2000_wdt_open,
+ .release = ixp2000_wdt_release,
+};
+
+static struct miscdevice ixp2000_wdt_miscdev =
+{
+ .minor = WATCHDOG_MINOR,
+ .name = "IXP2000 Watchdog",
+ .fops = &ixp2000_wdt_fops,
+};
+
+static int __init ixp2000_wdt_init(void)
+{
+ wdt_tick_rate = (*IXP2000_T1_CLD * HZ)/ 256;;
+
+ return misc_register(&ixp2000_wdt_miscdev);
+}
+
+static void __exit ixp2000_wdt_exit(void)
+{
+ misc_deregister(&ixp2000_wdt_miscdev);
+}
+
+module_init(ixp2000_wdt_init);
+module_exit(ixp2000_wdt_exit);
+
+MODULE_AUTHOR("Deepak Saxena <dsaxena@plexity.net">);
+MODULE_DESCRIPTION("IXP2000 Network Processor Watchdog");
+
+module_param(heartbeat, int, 0);
+MODULE_PARM_DESC(heartbeat, "Watchdog heartbeat in seconds (default 60s)");
+
+module_param(nowayout, int, 0);
+MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started");
+
+MODULE_LICENSE("GPL");
+MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
+