--- /dev/null
+/*
+ * SBC EPX C3 0.1 A Hardware Watchdog Device for the Winsystems EPX-C3
+ * single board computer
+ *
+ * (c) Copyright 2006 Calin A. Culianu <calin@ajvar.org>, 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.
+ *
+ * based on softdog.c by Alan Cox <alan@redhat.com>
+ */
+
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/config.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/notifier.h>
+#include <linux/reboot.h>
+#include <linux/init.h>
+#include <linux/ioport.h>
+#include <asm/uaccess.h>
+#include <asm/io.h>
+
+#define PFX "epx_c3: "
+static int epx_c3_alive;
+
+#define WATCHDOG_TIMEOUT 1 /* 1 sec default timeout */
+
+static int nowayout = WATCHDOG_NOWAYOUT;
+module_param(nowayout, int, 0);
+MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=CONFIG_WATCHDOG_NOWAYOUT)");
+
+#define EPXC3_WATCHDOG_CTL_REG 0x1ee /* write 1 to enable, 0 to disable */
+#define EPXC3_WATCHDOG_PET_REG 0x1ef /* write anything to pet once enabled */
+
+static void epx_c3_start(void)
+{
+ outb(1, EPXC3_WATCHDOG_CTL_REG);
+}
+
+static void epx_c3_stop(void)
+{
+
+ outb(0, EPXC3_WATCHDOG_CTL_REG);
+
+ printk(KERN_INFO PFX "Stopped watchdog timer.\n");
+}
+
+static void epx_c3_pet(void)
+{
+ outb(1, EPXC3_WATCHDOG_PET_REG);
+}
+
+/*
+ * Allow only one person to hold it open
+ */
+static int epx_c3_open(struct inode *inode, struct file *file)
+{
+ if (epx_c3_alive)
+ return -EBUSY;
+
+ if (nowayout)
+ __module_get(THIS_MODULE);
+
+ /* Activate timer */
+ epx_c3_start();
+ epx_c3_pet();
+
+ epx_c3_alive = 1;
+ printk(KERN_INFO "Started watchdog timer.\n");
+
+ return nonseekable_open(inode, file);
+}
+
+static int epx_c3_release(struct inode *inode, struct file *file)
+{
+ /* Shut off the timer.
+ * Lock it in if it's a module and we defined ...NOWAYOUT */
+ if (!nowayout)
+ epx_c3_stop(); /* Turn the WDT off */
+
+ epx_c3_alive = 0;
+
+ return 0;
+}
+
+static ssize_t epx_c3_write(struct file *file, const char __user *data,
+ size_t len, loff_t *ppos)
+{
+ /* Refresh the timer. */
+ if (len)
+ epx_c3_pet();
+ return len;
+}
+
+static int epx_c3_ioctl(struct inode *inode, struct file *file,
+ unsigned int cmd, unsigned long arg)
+{
+ int options, retval = -EINVAL;
+ int __user *argp = (void __user *)arg;
+ static struct watchdog_info ident = {
+ .options = WDIOF_KEEPALIVEPING |
+ WDIOF_MAGICCLOSE,
+ .firmware_version = 0,
+ .identity = "Winsystems EPX-C3 H/W Watchdog",
+ };
+
+ switch (cmd) {
+ case WDIOC_GETSUPPORT:
+ if (copy_to_user(argp, &ident, sizeof(ident)))
+ return -EFAULT;
+ return 0;
+ case WDIOC_GETSTATUS:
+ case WDIOC_GETBOOTSTATUS:
+ return put_user(0, argp);
+ case WDIOC_KEEPALIVE:
+ epx_c3_pet();
+ return 0;
+ case WDIOC_GETTIMEOUT:
+ return put_user(WATCHDOG_TIMEOUT, argp);
+ case WDIOC_SETOPTIONS:
+ if (get_user(options, argp))
+ return -EFAULT;
+
+ if (options & WDIOS_DISABLECARD) {
+ epx_c3_stop();
+ retval = 0;
+ }
+
+ if (options & WDIOS_ENABLECARD) {
+ epx_c3_start();
+ retval = 0;
+ }
+
+ return retval;
+ default:
+ return -ENOIOCTLCMD;
+ }
+}
+
+static int epx_c3_notify_sys(struct notifier_block *this, unsigned long code,
+ void *unused)
+{
+ if (code == SYS_DOWN || code == SYS_HALT)
+ epx_c3_stop(); /* Turn the WDT off */
+
+ return NOTIFY_DONE;
+}
+
+static struct file_operations epx_c3_fops = {
+ .owner = THIS_MODULE,
+ .llseek = no_llseek,
+ .write = epx_c3_write,
+ .ioctl = epx_c3_ioctl,
+ .open = epx_c3_open,
+ .release = epx_c3_release,
+};
+
+static struct miscdevice epx_c3_miscdev = {
+ .minor = WATCHDOG_MINOR,
+ .name = "watchdog",
+ .fops = &epx_c3_fops,
+};
+
+static struct notifier_block epx_c3_notifier = {
+ .notifier_call = epx_c3_notify_sys,
+};
+
+static const char banner[] __initdata =
+ KERN_INFO PFX "Hardware Watchdog Timer for Winsystems EPX-C3 SBC: 0.1\n";
+
+static int __init watchdog_init(void)
+{
+ int ret;
+
+ if (!request_region(EPXC3_WATCHDOG_CTL_REG, 2, "epxc3_watchdog"))
+ return -EBUSY;
+
+ ret = register_reboot_notifier(&epx_c3_notifier);
+ if (ret) {
+ printk(KERN_ERR PFX "cannot register reboot notifier "
+ "(err=%d)\n", ret);
+ goto out;
+ }
+
+ ret = misc_register(&epx_c3_miscdev);
+ if (ret) {
+ printk(KERN_ERR PFX "cannot register miscdev on minor=%d "
+ "(err=%d)\n", WATCHDOG_MINOR, ret);
+ unregister_reboot_notifier(&epx_c3_notifier);
+ goto out;
+ }
+
+ printk(banner);
+
+ return 0;
+
+out:
+ release_region(EPXC3_WATCHDOG_CTL_REG, 2);
+ return ret;
+}
+
+static void __exit watchdog_exit(void)
+{
+ misc_deregister(&epx_c3_miscdev);
+ unregister_reboot_notifier(&epx_c3_notifier);
+ release_region(EPXC3_WATCHDOG_CTL_REG, 2);
+}
+
+module_init(watchdog_init);
+module_exit(watchdog_exit);
+
+MODULE_AUTHOR("Calin A. Culianu <calin@ajvar.org>");
+MODULE_DESCRIPTION("Hardware Watchdog Device for Winsystems EPX-C3 SBC. Note that there is no way to probe for this device -- so only use it if you are *sure* you are runnning on this specific SBC system from Winsystems! It writes to IO ports 0x1ee and 0x1ef!");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
git://git.onelab.eu / linux-2.6.git / blobdiff