--- /dev/null
+/*
+ * drivers/char/watchdog/ixp4xx_wdt.c
+ *
+ * Watchdog driver for Intel IXP4xx network processors
+ *
+ * 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.
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#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 <linux/uaccess.h>
+#include <mach/hardware.h>
+
+static bool nowayout = WATCHDOG_NOWAYOUT;
+static int heartbeat = 60; /* (secs) Default is 1 minute */
+static unsigned long wdt_status;
+static unsigned long boot_status;
+static DEFINE_SPINLOCK(wdt_lock);
+
+#define WDT_TICK_RATE (IXP4XX_PERIPHERAL_BUS_CLOCK * 1000000UL)
+
+#define WDT_IN_USE 0
+#define WDT_OK_TO_CLOSE 1
+
+static void wdt_enable(void)
+{
+ spin_lock(&wdt_lock);
+ *IXP4XX_OSWK = IXP4XX_WDT_KEY;
+ *IXP4XX_OSWE = 0;
+ *IXP4XX_OSWT = WDT_TICK_RATE * heartbeat;
+ *IXP4XX_OSWE = IXP4XX_WDT_COUNT_ENABLE | IXP4XX_WDT_RESET_ENABLE;
+ *IXP4XX_OSWK = 0;
+ spin_unlock(&wdt_lock);
+}
+
+static void wdt_disable(void)
+{
+ spin_lock(&wdt_lock);
+ *IXP4XX_OSWK = IXP4XX_WDT_KEY;
+ *IXP4XX_OSWE = 0;
+ *IXP4XX_OSWK = 0;
+ spin_unlock(&wdt_lock);
+}
+
+static int ixp4xx_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
+ixp4xx_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_enable();
+ }
+ return len;
+}
+
+static const struct watchdog_info ident = {
+ .options = WDIOF_CARDRESET | WDIOF_MAGICCLOSE |
+ WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING,
+ .identity = "IXP4xx Watchdog",
+};
+
+
+static long ixp4xx_wdt_ioctl(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(boot_status, (int *)arg);
+ break;
+
+ case WDIOC_KEEPALIVE:
+ wdt_enable();
+ ret = 0;
+ break;
+
+ case WDIOC_SETTIMEOUT:
+ ret = get_user(time, (int *)arg);
+ if (ret)
+ break;
+
+ if (time <= 0 || time > 60) {
+ ret = -EINVAL;
+ break;
+ }
+
+ heartbeat = time;
+ wdt_enable();
+ /* Fall through */
+
+ case WDIOC_GETTIMEOUT:
+ ret = put_user(heartbeat, (int *)arg);
+ break;
+ }
+ return ret;
+}
+
+static int ixp4xx_wdt_release(struct inode *inode, struct file *file)
+{
+ if (test_bit(WDT_OK_TO_CLOSE, &wdt_status))
+ wdt_disable();
+ else
+ pr_crit("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 ixp4xx_wdt_fops = {
+ .owner = THIS_MODULE,
+ .llseek = no_llseek,
+ .write = ixp4xx_wdt_write,
+ .unlocked_ioctl = ixp4xx_wdt_ioctl,
+ .open = ixp4xx_wdt_open,
+ .release = ixp4xx_wdt_release,
+};
+
+static struct miscdevice ixp4xx_wdt_miscdev = {
+ .minor = WATCHDOG_MINOR,
+ .name = "watchdog",
+ .fops = &ixp4xx_wdt_fops,
+};
+
+static int __init ixp4xx_wdt_init(void)
+{
+ int ret;
+
+ if (!(read_cpuid_id() & 0xf) && !cpu_is_ixp46x()) {
+ pr_err("Rev. A0 IXP42x CPU detected - watchdog disabled\n");
+
+ return -ENODEV;
+ }
+ boot_status = (*IXP4XX_OSST & IXP4XX_OSST_TIMER_WARM_RESET) ?
+ WDIOF_CARDRESET : 0;
+ ret = misc_register(&ixp4xx_wdt_miscdev);
+ if (ret == 0)
+ pr_info("timer heartbeat %d sec\n", heartbeat);
+ return ret;
+}
+
+static void __exit ixp4xx_wdt_exit(void)
+{
+ misc_deregister(&ixp4xx_wdt_miscdev);
+}
+
+
+module_init(ixp4xx_wdt_init);
+module_exit(ixp4xx_wdt_exit);
+
+MODULE_AUTHOR("Deepak Saxena <dsaxena@plexity.net>");
+MODULE_DESCRIPTION("IXP4xx Network Processor Watchdog");
+
+module_param(heartbeat, int, 0);
+MODULE_PARM_DESC(heartbeat, "Watchdog heartbeat in seconds (default 60s)");
+
+module_param(nowayout, bool, 0);
+MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started");
+
+MODULE_LICENSE("GPL");
Code Review / kvmfornfv.git / blobdiff