release/src-rt-6.x.4708/linux/linux-2.6.36/drivers/watchdog/mixcomwd.c

   1 /*
   2  * MixCom Watchdog: A Simple Hardware Watchdog Device
   3  * Based on Softdog driver by Alan Cox and PC Watchdog driver by Ken Hollis
   4  *
   5  * Author: Gergely Madarasz <gorgo@itc.hu>
   6  *
   7  * Copyright (c) 1999 ITConsult-Pro Co. <info@itc.hu>
   8  *
   9  * This program is free software; you can redistribute it and/or
  10  * modify it under the terms of the GNU General Public License
  11  * as published by the Free Software Foundation; either version
  12  * 2 of the License, or (at your option) any later version.
  13  *
  14  * Version 0.1 (99/04/15):
  15  *              - first version
  16  *
  17  * Version 0.2 (99/06/16):
  18  *              - added kernel timer watchdog ping after close
  19  *                since the hardware does not support watchdog shutdown
  20  *
  21  * Version 0.3 (99/06/21):
  22  *              - added WDIOC_GETSTATUS and WDIOC_GETSUPPORT ioctl calls
  23  *
  24  * Version 0.3.1 (99/06/22):
  25  *              - allow module removal while internal timer is active,
  26  *                print warning about probable reset
  27  *
  28  * Version 0.4 (99/11/15):
  29  *              - support for one more type board
  30  *
  31  * Version 0.5 (2001/12/14) Matt Domsch <Matt_Domsch@dell.com>
  32  *              - added nowayout module option to override
  33  *                CONFIG_WATCHDOG_NOWAYOUT
  34  *
  35  * Version 0.6 (2002/04/12): Rob Radez <rob@osinvestor.com>
  36  *              - make mixcomwd_opened unsigned,
  37  *                removed lock_kernel/unlock_kernel from mixcomwd_release,
  38  *                modified ioctl a bit to conform to API
  39  *
  40  */
  41
  42 #define VERSION "0.6"
  43 #define WATCHDOG_NAME "mixcomwd"
  44 #define PFX WATCHDOG_NAME ": "
  45
  46 #include <linux/module.h>
  47 #include <linux/moduleparam.h>
  48 #include <linux/types.h>
  49 #include <linux/miscdevice.h>
  50 #include <linux/ioport.h>
  51 #include <linux/watchdog.h>
  52 #include <linux/fs.h>
  53 #include <linux/reboot.h>
  54 #include <linux/init.h>
  55 #include <linux/jiffies.h>
  56 #include <linux/timer.h>
  57 #include <linux/uaccess.h>
  58 #include <linux/io.h>
  59
  60 /*
  61  * We have two types of cards that can be probed:
  62  * 1) The Mixcom cards: these cards can be found at addresses
  63  *    0x180, 0x280, 0x380 with an additional offset of 0xc10.
  64  *    (Or 0xd90, 0xe90, 0xf90).
  65  * 2) The FlashCOM cards: these cards can be set up at
  66  *    0x300 -> 0x378, in 0x8 jumps with an offset of 0x04.
  67  *    (Or 0x304 -> 0x37c in 0x8 jumps).
  68  *    Each card has it's own ID.
  69  */
  70 #define MIXCOM_ID 0x11
  71 #define FLASHCOM_ID 0x18
  72 static struct {
  73         int ioport;
  74         int id;
  75 } mixcomwd_io_info[] __devinitdata = {
  76         /* The Mixcom cards */
  77         {0x0d90, MIXCOM_ID},
  78         {0x0e90, MIXCOM_ID},
  79         {0x0f90, MIXCOM_ID},
  80         /* The FlashCOM cards */
  81         {0x0304, FLASHCOM_ID},
  82         {0x030c, FLASHCOM_ID},
  83         {0x0314, FLASHCOM_ID},
  84         {0x031c, FLASHCOM_ID},
  85         {0x0324, FLASHCOM_ID},
  86         {0x032c, FLASHCOM_ID},
  87         {0x0334, FLASHCOM_ID},
  88         {0x033c, FLASHCOM_ID},
  89         {0x0344, FLASHCOM_ID},
  90         {0x034c, FLASHCOM_ID},
  91         {0x0354, FLASHCOM_ID},
  92         {0x035c, FLASHCOM_ID},
  93         {0x0364, FLASHCOM_ID},
  94         {0x036c, FLASHCOM_ID},
  95         {0x0374, FLASHCOM_ID},
  96         {0x037c, FLASHCOM_ID},
  97         /* The end of the list */
  98         {0x0000, 0},
  99 };
 100
 101 static void mixcomwd_timerfun(unsigned long d);
 102
 103 static unsigned long mixcomwd_opened; /* long req'd for setbit --RR */
 104
 105 static int watchdog_port;
 106 static int mixcomwd_timer_alive;
 107 static DEFINE_TIMER(mixcomwd_timer, mixcomwd_timerfun, 0, 0);
 108 static char expect_close;
 109
 110 static int nowayout = WATCHDOG_NOWAYOUT;
 111 module_param(nowayout, int, 0);
 112 MODULE_PARM_DESC(nowayout,
 113                 "Watchdog cannot be stopped once started (default="
 114                                 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
 115
 116 static void mixcomwd_ping(void)
 117 {
 118         outb_p(55, watchdog_port);
 119         return;
 120 }
 121
 122 static void mixcomwd_timerfun(unsigned long d)
 123 {
 124         mixcomwd_ping();
 125         mod_timer(&mixcomwd_timer, jiffies + 5 * HZ);
 126 }
 127
 128 /*
 129  *      Allow only one person to hold it open
 130  */
 131
 132 static int mixcomwd_open(struct inode *inode, struct file *file)
 133 {
 134         if (test_and_set_bit(0, &mixcomwd_opened))
 135                 return -EBUSY;
 136
 137         mixcomwd_ping();
 138
 139         if (nowayout)
 140                 /*
 141                  * fops_get() code via open() has already done
 142                  * a try_module_get() so it is safe to do the
 143                  * __module_get().
 144                  */
 145                 __module_get(THIS_MODULE);
 146         else {
 147                 if (mixcomwd_timer_alive) {
 148                         del_timer(&mixcomwd_timer);
 149                         mixcomwd_timer_alive = 0;
 150                 }
 151         }
 152         return nonseekable_open(inode, file);
 153 }
 154
 155 static int mixcomwd_release(struct inode *inode, struct file *file)
 156 {
 157         if (expect_close == 42) {
 158                 if (mixcomwd_timer_alive) {
 159                         printk(KERN_ERR PFX
 160                                 "release called while internal timer alive");
 161                         return -EBUSY;
 162                 }
 163                 mixcomwd_timer_alive = 1;
 164                 mod_timer(&mixcomwd_timer, jiffies + 5 * HZ);
 165         } else
 166                 printk(KERN_CRIT PFX
 167                     "WDT device closed unexpectedly.  WDT will not stop!\n");
 168
 169         clear_bit(0, &mixcomwd_opened);
 170         expect_close = 0;
 171         return 0;
 172 }
 173
 174
 175 static ssize_t mixcomwd_write(struct file *file, const char __user *data,
 176                                                 size_t len, loff_t *ppos)
 177 {
 178         if (len) {
 179                 if (!nowayout) {
 180                         size_t i;
 181
 182                         /* In case it was set long ago */
 183                         expect_close = 0;
 184
 185                         for (i = 0; i != len; i++) {
 186                                 char c;
 187                                 if (get_user(c, data + i))
 188                                         return -EFAULT;
 189                                 if (c == 'V')
 190                                         expect_close = 42;
 191                         }
 192                 }
 193                 mixcomwd_ping();
 194         }
 195         return len;
 196 }
 197
 198 static long mixcomwd_ioctl(struct file *file,
 199                                 unsigned int cmd, unsigned long arg)
 200 {
 201         void __user *argp = (void __user *)arg;
 202         int __user *p = argp;
 203         int status;
 204         static const struct watchdog_info ident = {
 205                 .options = WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE,
 206                 .firmware_version = 1,
 207                 .identity = "MixCOM watchdog",
 208         };
 209
 210         switch (cmd) {
 211         case WDIOC_GETSUPPORT:
 212                 if (copy_to_user(argp, &ident, sizeof(ident)))
 213                         return -EFAULT;
 214                 break;
 215         case WDIOC_GETSTATUS:
 216                 status = mixcomwd_opened;
 217                 if (!nowayout)
 218                         status |= mixcomwd_timer_alive;
 219                 return put_user(status, p);
 220         case WDIOC_GETBOOTSTATUS:
 221                 return put_user(0, p);
 222         case WDIOC_KEEPALIVE:
 223                 mixcomwd_ping();
 224                 break;
 225         default:
 226                 return -ENOTTY;
 227         }
 228         return 0;
 229 }
 230
 231 static const struct file_operations mixcomwd_fops = {
 232         .owner          = THIS_MODULE,
 233         .llseek         = no_llseek,
 234         .write          = mixcomwd_write,
 235         .unlocked_ioctl = mixcomwd_ioctl,
 236         .open           = mixcomwd_open,
 237         .release        = mixcomwd_release,
 238 };
 239
 240 static struct miscdevice mixcomwd_miscdev = {
 241         .minor  = WATCHDOG_MINOR,
 242         .name   = "watchdog",
 243         .fops   = &mixcomwd_fops,
 244 };
 245
 246 static int __init checkcard(int port, int card_id)
 247 {
 248         int id;
 249
 250         if (!request_region(port, 1, "MixCOM watchdog"))
 251                 return 0;
 252
 253         id = inb_p(port);
 254         if (card_id == MIXCOM_ID)
 255                 id &= 0x3f;
 256
 257         if (id != card_id) {
 258                 release_region(port, 1);
 259                 return 0;
 260         }
 261         return 1;
 262 }
 263
 264 static int __init mixcomwd_init(void)
 265 {
 266         int i, ret, found = 0;
 267
 268         for (i = 0; !found && mixcomwd_io_info[i].ioport != 0; i++) {
 269                 if (checkcard(mixcomwd_io_info[i].ioport,
 270                               mixcomwd_io_info[i].id)) {
 271                         found = 1;
 272                         watchdog_port = mixcomwd_io_info[i].ioport;
 273                 }
 274         }
 275
 276         if (!found) {
 277                 printk(KERN_ERR PFX
 278                         "No card detected, or port not available.\n");
 279                 return -ENODEV;
 280         }
 281
 282         ret = misc_register(&mixcomwd_miscdev);
 283         if (ret) {
 284                 printk(KERN_ERR PFX
 285                         "cannot register miscdev on minor=%d (err=%d)\n",
 286                                         WATCHDOG_MINOR, ret);
 287                 goto error_misc_register_watchdog;
 288         }
 289
 290         printk(KERN_INFO
 291                 "MixCOM watchdog driver v%s, watchdog port at 0x%3x\n",
 292                                         VERSION, watchdog_port);
 293
 294         return 0;
 295
 296 error_misc_register_watchdog:
 297         release_region(watchdog_port, 1);
 298         watchdog_port = 0x0000;
 299         return ret;
 300 }
 301
 302 static void __exit mixcomwd_exit(void)
 303 {
 304         if (!nowayout) {
 305                 if (mixcomwd_timer_alive) {
 306                         printk(KERN_WARNING PFX "I quit now, hardware will"
 307                                " probably reboot!\n");
 308                         del_timer_sync(&mixcomwd_timer);
 309                         mixcomwd_timer_alive = 0;
 310                 }
 311         }
 312         misc_deregister(&mixcomwd_miscdev);
 313         release_region(watchdog_port, 1);
 314 }
 315
 316 module_init(mixcomwd_init);
 317 module_exit(mixcomwd_exit);
 318
 319 MODULE_AUTHOR("Gergely Madarasz <gorgo@itc.hu>");
 320 MODULE_DESCRIPTION("MixCom Watchdog driver");
 321 MODULE_VERSION(VERSION);
 322 MODULE_LICENSE("GPL");
 323 MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);