1 files changed, 219 insertions, 0 deletions

diff --git a/drivers/watchdog/ixp2000_wdt.c b/drivers/watchdog/ixp2000_wdt.c
new file mode 100644
index 000000000000..dc7548dcaf35
--- /dev/null
+++ b/drivers/watchdog/ixp2000_wdt.c
@@ -0,0 +1,219 @@
+/*
+ * drivers/char/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/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>
+
+static int nowayout = WATCHDOG_NOWAYOUT;
+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 = -ENOTTY;
+        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 unexpectedly - "
+                                        "timer will not stop\n");
+        }
+
+        clear_bit(WDT_IN_USE, &wdt_status);
+        clear_bit(WDT_OK_TO_CLOSE, &wdt_status);
+
+        return 0;
+}
+
+
+static const 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           = "watchdog",
+        .fops           = &ixp2000_wdt_fops,
+};
+
+static int __init ixp2000_wdt_init(void)
+{
+        if ((*IXP2000_PRODUCT_ID & 0x001ffef0) == 0x00000000) {
+                printk(KERN_INFO "Unable to use IXP2000 watchdog due to IXP2800 erratum #25.\n");
+                return -EIO;
+        }
+
+        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);
+