--- /dev/null
+/*
+ * Intel 21285 watchdog driver
+ * Copyright (c) Phil Blundell <pb@nexus.co.uk>, 1998
+ *
+ * based on
+ *
+ * SoftDog 0.05: A Software Watchdog Device
+ *
+ * (c) Copyright 1996 Alan Cox <alan@lxorguk.ukuu.org.uk>,
+ * All Rights Reserved.
+ *
+ * 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.
+ *
+ */
+
+#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/mm.h>
+#include <linux/miscdevice.h>
+#include <linux/watchdog.h>
+#include <linux/reboot.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/uaccess.h>
+#include <linux/irq.h>
+#include <mach/hardware.h>
+
+#include <asm/mach-types.h>
+#include <asm/system_info.h>
+#include <asm/hardware/dec21285.h>
+
+/*
+ * Define this to stop the watchdog actually rebooting the machine.
+ */
+#undef ONLY_TESTING
+
+static unsigned int soft_margin = 60; /* in seconds */
+static unsigned int reload;
+static unsigned long timer_alive;
+
+#ifdef ONLY_TESTING
+/*
+ * If the timer expires..
+ */
+static void watchdog_fire(int irq, void *dev_id)
+{
+ pr_crit("Would Reboot\n");
+ *CSR_TIMER4_CNTL = 0;
+ *CSR_TIMER4_CLR = 0;
+}
+#endif
+
+/*
+ * Refresh the timer.
+ */
+static void watchdog_ping(void)
+{
+ *CSR_TIMER4_LOAD = reload;
+}
+
+/*
+ * Allow only one person to hold it open
+ */
+static int watchdog_open(struct inode *inode, struct file *file)
+{
+ int ret;
+
+ if (*CSR_SA110_CNTL & (1 << 13))
+ return -EBUSY;
+
+ if (test_and_set_bit(1, &timer_alive))
+ return -EBUSY;
+
+ reload = soft_margin * (mem_fclk_21285 / 256);
+
+ *CSR_TIMER4_CLR = 0;
+ watchdog_ping();
+ *CSR_TIMER4_CNTL = TIMER_CNTL_ENABLE | TIMER_CNTL_AUTORELOAD
+ | TIMER_CNTL_DIV256;
+
+#ifdef ONLY_TESTING
+ ret = request_irq(IRQ_TIMER4, watchdog_fire, 0, "watchdog", NULL);
+ if (ret) {
+ *CSR_TIMER4_CNTL = 0;
+ clear_bit(1, &timer_alive);
+ }
+#else
+ /*
+ * Setting this bit is irreversible; once enabled, there is
+ * no way to disable the watchdog.
+ */
+ *CSR_SA110_CNTL |= 1 << 13;
+
+ ret = 0;
+#endif
+ nonseekable_open(inode, file);
+ return ret;
+}
+
+/*
+ * Shut off the timer.
+ * Note: if we really have enabled the watchdog, there
+ * is no way to turn off.
+ */
+static int watchdog_release(struct inode *inode, struct file *file)
+{
+#ifdef ONLY_TESTING
+ free_irq(IRQ_TIMER4, NULL);
+ clear_bit(1, &timer_alive);
+#endif
+ return 0;
+}
+
+static ssize_t watchdog_write(struct file *file, const char __user *data,
+ size_t len, loff_t *ppos)
+{
+ /*
+ * Refresh the timer.
+ */
+ if (len)
+ watchdog_ping();
+
+ return len;
+}
+
+static const struct watchdog_info ident = {
+ .options = WDIOF_SETTIMEOUT,
+ .identity = "Footbridge Watchdog",
+};
+
+static long watchdog_ioctl(struct file *file, unsigned int cmd,
+ unsigned long arg)
+{
+ int __user *int_arg = (int __user *)arg;
+ int new_margin, ret = -ENOTTY;
+
+ switch (cmd) {
+ case WDIOC_GETSUPPORT:
+ ret = 0;
+ if (copy_to_user((void __user *)arg, &ident, sizeof(ident)))
+ ret = -EFAULT;
+ break;
+
+ case WDIOC_GETSTATUS:
+ case WDIOC_GETBOOTSTATUS:
+ ret = put_user(0, int_arg);
+ break;
+
+ case WDIOC_KEEPALIVE:
+ watchdog_ping();
+ ret = 0;
+ break;
+
+ case WDIOC_SETTIMEOUT:
+ ret = get_user(new_margin, int_arg);
+ if (ret)
+ break;
+
+ /* Arbitrary, can't find the card's limits */
+ if (new_margin < 0 || new_margin > 60) {
+ ret = -EINVAL;
+ break;
+ }
+
+ soft_margin = new_margin;
+ reload = soft_margin * (mem_fclk_21285 / 256);
+ watchdog_ping();
+ /* Fall */
+ case WDIOC_GETTIMEOUT:
+ ret = put_user(soft_margin, int_arg);
+ break;
+ }
+ return ret;
+}
+
+static const struct file_operations watchdog_fops = {
+ .owner = THIS_MODULE,
+ .llseek = no_llseek,
+ .write = watchdog_write,
+ .unlocked_ioctl = watchdog_ioctl,
+ .open = watchdog_open,
+ .release = watchdog_release,
+};
+
+static struct miscdevice watchdog_miscdev = {
+ .minor = WATCHDOG_MINOR,
+ .name = "watchdog",
+ .fops = &watchdog_fops,
+};
+
+static int __init footbridge_watchdog_init(void)
+{
+ int retval;
+
+ if (machine_is_netwinder())
+ return -ENODEV;
+
+ retval = misc_register(&watchdog_miscdev);
+ if (retval < 0)
+ return retval;
+
+ pr_info("Footbridge Watchdog Timer: 0.01, timer margin: %d sec\n",
+ soft_margin);
+
+ if (machine_is_cats())
+ pr_warn("Warning: Watchdog reset may not work on this machine\n");
+ return 0;
+}
+
+static void __exit footbridge_watchdog_exit(void)
+{
+ misc_deregister(&watchdog_miscdev);
+}
+
+MODULE_AUTHOR("Phil Blundell <pb@nexus.co.uk>");
+MODULE_DESCRIPTION("Footbridge watchdog driver");
+MODULE_LICENSE("GPL");
+
+module_param(soft_margin, int, 0);
+MODULE_PARM_DESC(soft_margin, "Watchdog timeout in seconds");
+
+module_init(footbridge_watchdog_init);
+module_exit(footbridge_watchdog_exit);
Code Review / kvmfornfv.git / blobdiff