--- /dev/null
+/*
+ * MixCom Watchdog: A Simple Hardware Watchdog Device
+ * Based on Softdog driver by Alan Cox and PC Watchdog driver by Ken Hollis
+ *
+ * Author: Gergely Madarasz <gorgo@itc.hu>
+ *
+ * Copyright (c) 1999 ITConsult-Pro Co. <info@itc.hu>
+ *
+ * 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.
+ *
+ * Version 0.1 (99/04/15):
+ * - first version
+ *
+ * Version 0.2 (99/06/16):
+ * - added kernel timer watchdog ping after close
+ * since the hardware does not support watchdog shutdown
+ *
+ * Version 0.3 (99/06/21):
+ * - added WDIOC_GETSTATUS and WDIOC_GETSUPPORT ioctl calls
+ *
+ * Version 0.3.1 (99/06/22):
+ * - allow module removal while internal timer is active,
+ * print warning about probable reset
+ *
+ * Version 0.4 (99/11/15):
+ * - support for one more type board
+ *
+ * Version 0.5 (2001/12/14) Matt Domsch <Matt_Domsch@dell.com>
+ * - added nowayout module option to override
+ * CONFIG_WATCHDOG_NOWAYOUT
+ *
+ * Version 0.6 (2002/04/12): Rob Radez <rob@osinvestor.com>
+ * - make mixcomwd_opened unsigned,
+ * removed lock_kernel/unlock_kernel from mixcomwd_release,
+ * modified ioctl a bit to conform to API
+ *
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#define VERSION "0.6"
+#define WATCHDOG_NAME "mixcomwd"
+
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/types.h>
+#include <linux/miscdevice.h>
+#include <linux/ioport.h>
+#include <linux/watchdog.h>
+#include <linux/fs.h>
+#include <linux/reboot.h>
+#include <linux/init.h>
+#include <linux/jiffies.h>
+#include <linux/timer.h>
+#include <linux/uaccess.h>
+#include <linux/io.h>
+
+/*
+ * We have two types of cards that can be probed:
+ * 1) The Mixcom cards: these cards can be found at addresses
+ * 0x180, 0x280, 0x380 with an additional offset of 0xc10.
+ * (Or 0xd90, 0xe90, 0xf90).
+ * 2) The FlashCOM cards: these cards can be set up at
+ * 0x300 -> 0x378, in 0x8 jumps with an offset of 0x04.
+ * (Or 0x304 -> 0x37c in 0x8 jumps).
+ * Each card has it's own ID.
+ */
+#define MIXCOM_ID 0x11
+#define FLASHCOM_ID 0x18
+static struct {
+ int ioport;
+ int id;
+} mixcomwd_io_info[] = {
+ /* The Mixcom cards */
+ {0x0d90, MIXCOM_ID},
+ {0x0e90, MIXCOM_ID},
+ {0x0f90, MIXCOM_ID},
+ /* The FlashCOM cards */
+ {0x0304, FLASHCOM_ID},
+ {0x030c, FLASHCOM_ID},
+ {0x0314, FLASHCOM_ID},
+ {0x031c, FLASHCOM_ID},
+ {0x0324, FLASHCOM_ID},
+ {0x032c, FLASHCOM_ID},
+ {0x0334, FLASHCOM_ID},
+ {0x033c, FLASHCOM_ID},
+ {0x0344, FLASHCOM_ID},
+ {0x034c, FLASHCOM_ID},
+ {0x0354, FLASHCOM_ID},
+ {0x035c, FLASHCOM_ID},
+ {0x0364, FLASHCOM_ID},
+ {0x036c, FLASHCOM_ID},
+ {0x0374, FLASHCOM_ID},
+ {0x037c, FLASHCOM_ID},
+ /* The end of the list */
+ {0x0000, 0},
+};
+
+static void mixcomwd_timerfun(unsigned long d);
+
+static unsigned long mixcomwd_opened; /* long req'd for setbit --RR */
+
+static int watchdog_port;
+static int mixcomwd_timer_alive;
+static DEFINE_TIMER(mixcomwd_timer, mixcomwd_timerfun, 0, 0);
+static char expect_close;
+
+static bool nowayout = WATCHDOG_NOWAYOUT;
+module_param(nowayout, bool, 0);
+MODULE_PARM_DESC(nowayout,
+ "Watchdog cannot be stopped once started (default="
+ __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
+
+static void mixcomwd_ping(void)
+{
+ outb_p(55, watchdog_port);
+ return;
+}
+
+static void mixcomwd_timerfun(unsigned long d)
+{
+ mixcomwd_ping();
+ mod_timer(&mixcomwd_timer, jiffies + 5 * HZ);
+}
+
+/*
+ * Allow only one person to hold it open
+ */
+
+static int mixcomwd_open(struct inode *inode, struct file *file)
+{
+ if (test_and_set_bit(0, &mixcomwd_opened))
+ return -EBUSY;
+
+ mixcomwd_ping();
+
+ if (nowayout)
+ /*
+ * fops_get() code via open() has already done
+ * a try_module_get() so it is safe to do the
+ * __module_get().
+ */
+ __module_get(THIS_MODULE);
+ else {
+ if (mixcomwd_timer_alive) {
+ del_timer(&mixcomwd_timer);
+ mixcomwd_timer_alive = 0;
+ }
+ }
+ return nonseekable_open(inode, file);
+}
+
+static int mixcomwd_release(struct inode *inode, struct file *file)
+{
+ if (expect_close == 42) {
+ if (mixcomwd_timer_alive) {
+ pr_err("release called while internal timer alive\n");
+ return -EBUSY;
+ }
+ mixcomwd_timer_alive = 1;
+ mod_timer(&mixcomwd_timer, jiffies + 5 * HZ);
+ } else
+ pr_crit("WDT device closed unexpectedly. WDT will not stop!\n");
+
+ clear_bit(0, &mixcomwd_opened);
+ expect_close = 0;
+ return 0;
+}
+
+
+static ssize_t mixcomwd_write(struct file *file, const char __user *data,
+ size_t len, loff_t *ppos)
+{
+ if (len) {
+ if (!nowayout) {
+ size_t i;
+
+ /* In case it was set long ago */
+ expect_close = 0;
+
+ for (i = 0; i != len; i++) {
+ char c;
+ if (get_user(c, data + i))
+ return -EFAULT;
+ if (c == 'V')
+ expect_close = 42;
+ }
+ }
+ mixcomwd_ping();
+ }
+ return len;
+}
+
+static long mixcomwd_ioctl(struct file *file,
+ unsigned int cmd, unsigned long arg)
+{
+ void __user *argp = (void __user *)arg;
+ int __user *p = argp;
+ int status;
+ static const struct watchdog_info ident = {
+ .options = WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE,
+ .firmware_version = 1,
+ .identity = "MixCOM watchdog",
+ };
+
+ switch (cmd) {
+ case WDIOC_GETSUPPORT:
+ if (copy_to_user(argp, &ident, sizeof(ident)))
+ return -EFAULT;
+ break;
+ case WDIOC_GETSTATUS:
+ status = mixcomwd_opened;
+ if (!nowayout)
+ status |= mixcomwd_timer_alive;
+ return put_user(status, p);
+ case WDIOC_GETBOOTSTATUS:
+ return put_user(0, p);
+ case WDIOC_KEEPALIVE:
+ mixcomwd_ping();
+ break;
+ default:
+ return -ENOTTY;
+ }
+ return 0;
+}
+
+static const struct file_operations mixcomwd_fops = {
+ .owner = THIS_MODULE,
+ .llseek = no_llseek,
+ .write = mixcomwd_write,
+ .unlocked_ioctl = mixcomwd_ioctl,
+ .open = mixcomwd_open,
+ .release = mixcomwd_release,
+};
+
+static struct miscdevice mixcomwd_miscdev = {
+ .minor = WATCHDOG_MINOR,
+ .name = "watchdog",
+ .fops = &mixcomwd_fops,
+};
+
+static int __init checkcard(int port, int card_id)
+{
+ int id;
+
+ if (!request_region(port, 1, "MixCOM watchdog"))
+ return 0;
+
+ id = inb_p(port);
+ if (card_id == MIXCOM_ID)
+ id &= 0x3f;
+
+ if (id != card_id) {
+ release_region(port, 1);
+ return 0;
+ }
+ return 1;
+}
+
+static int __init mixcomwd_init(void)
+{
+ int i, ret, found = 0;
+
+ for (i = 0; !found && mixcomwd_io_info[i].ioport != 0; i++) {
+ if (checkcard(mixcomwd_io_info[i].ioport,
+ mixcomwd_io_info[i].id)) {
+ found = 1;
+ watchdog_port = mixcomwd_io_info[i].ioport;
+ }
+ }
+
+ if (!found) {
+ pr_err("No card detected, or port not available\n");
+ return -ENODEV;
+ }
+
+ ret = misc_register(&mixcomwd_miscdev);
+ if (ret) {
+ pr_err("cannot register miscdev on minor=%d (err=%d)\n",
+ WATCHDOG_MINOR, ret);
+ goto error_misc_register_watchdog;
+ }
+
+ pr_info("MixCOM watchdog driver v%s, watchdog port at 0x%3x\n",
+ VERSION, watchdog_port);
+
+ return 0;
+
+error_misc_register_watchdog:
+ release_region(watchdog_port, 1);
+ watchdog_port = 0x0000;
+ return ret;
+}
+
+static void __exit mixcomwd_exit(void)
+{
+ if (!nowayout) {
+ if (mixcomwd_timer_alive) {
+ pr_warn("I quit now, hardware will probably reboot!\n");
+ del_timer_sync(&mixcomwd_timer);
+ mixcomwd_timer_alive = 0;
+ }
+ }
+ misc_deregister(&mixcomwd_miscdev);
+ release_region(watchdog_port, 1);
+}
+
+module_init(mixcomwd_init);
+module_exit(mixcomwd_exit);
+
+MODULE_AUTHOR("Gergely Madarasz <gorgo@itc.hu>");
+MODULE_DESCRIPTION("MixCom Watchdog driver");
+MODULE_VERSION(VERSION);
+MODULE_LICENSE("GPL");
Code Review / kvmfornfv.git / blobdiff