drivers/char/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  */
  29
  30 #define VERSION "0.3.1"
  31
  32 #include <linux/module.h>
  33 #include <linux/config.h>
  34 #include <linux/types.h>
  35 #include <linux/kernel.h>
  36 #include <linux/fs.h>
  37 #include <linux/mm.h>
  38 #include <linux/miscdevice.h>
  39 #include <linux/ioport.h>
  40 #include <linux/watchdog.h>
  41 #include <linux/reboot.h>
  42 #include <linux/init.h>
  43 #include <asm/uaccess.h>
  44 #include <asm/io.h>
  45
  46 static int mixcomwd_ioports[] = { 0x180, 0x280, 0x380, 0x000 };
  47
  48 #define MIXCOM_WATCHDOG_OFFSET 0xc10
  49 #define MIXCOM_ID1 0x11
  50 #define MIXCOM_ID2 0x13
  51
  52 static int mixcomwd_opened;
  53 static int mixcomwd_port;
  54
  55 #ifndef CONFIG_WATCHDOG_NOWAYOUT
  56 static int mixcomwd_timer_alive;
  57 static struct timer_list mixcomwd_timer;
  58 #endif
  59
  60 static void mixcomwd_ping(void)
  61 {
  62         outb_p(55,mixcomwd_port+MIXCOM_WATCHDOG_OFFSET);
  63         return;
  64 }
  65
  66 #ifndef CONFIG_WATCHDOG_NOWAYOUT
  67 static void mixcomwd_timerfun(unsigned long d)
  68 {
  69         mixcomwd_ping();
  70
  71         mod_timer(&mixcomwd_timer,jiffies+ 5*HZ);
  72 }
  73 #endif
  74
  75 /*
  76  *      Allow only one person to hold it open
  77  */
  78
  79 static int mixcomwd_open(struct inode *inode, struct file *file)
  80 {
  81         if(test_and_set_bit(0,&mixcomwd_opened)) {
  82                 return -EBUSY;
  83         }
  84         mixcomwd_ping();
  85
  86 #ifndef CONFIG_WATCHDOG_NOWAYOUT
  87         if(mixcomwd_timer_alive) {
  88                 del_timer(&mixcomwd_timer);
  89                 mixcomwd_timer_alive=0;
  90         }
  91 #endif
  92         MOD_INC_USE_COUNT;
  93
  94         return 0;
  95 }
  96
  97 static int mixcomwd_release(struct inode *inode, struct file *file)
  98 {
  99
 100 #ifndef CONFIG_WATCHDOG_NOWAYOUT
 101         if(mixcomwd_timer_alive) {
 102                 printk(KERN_ERR "mixcomwd: release called while internal timer alive");
 103                 return -EBUSY;
 104         }
 105         init_timer(&mixcomwd_timer);
 106         mixcomwd_timer.expires=jiffies + 5 * HZ;
 107         mixcomwd_timer.function=mixcomwd_timerfun;
 108         mixcomwd_timer.data=0;
 109         mixcomwd_timer_alive=1;
 110         add_timer(&mixcomwd_timer);
 111 #endif
 112         MOD_DEC_USE_COUNT;
 113
 114         clear_bit(0,&mixcomwd_opened);
 115         return 0;
 116 }
 117
 118
 119 static ssize_t mixcomwd_write(struct file *file, const char *data, size_t len, loff_t *ppos)
 120 {
 121         if (ppos != &file->f_pos) {
 122                 return -ESPIPE;
 123         }
 124
 125         if(len)
 126         {
 127                 mixcomwd_ping();
 128                 return 1;
 129         }
 130         return 0;
 131 }
 132
 133 static int mixcomwd_ioctl(struct inode *inode, struct file *file,
 134         unsigned int cmd, unsigned long arg)
 135 {
 136         int status;
 137         static struct watchdog_info ident = {
 138                 WDIOF_KEEPALIVEPING, 1, "MixCOM watchdog"
 139         };
 140
 141         switch(cmd)
 142         {
 143                 case WDIOC_GETSTATUS:
 144                         status=mixcomwd_opened;
 145 #ifndef CONFIG_WATCHDOG_NOWAYOUT
 146                         status|=mixcomwd_timer_alive;
 147 #endif
 148                         if (copy_to_user((int *)arg, &status, sizeof(int))) {
 149                                 return -EFAULT;
 150                         }
 151                         break;
 152                 case WDIOC_GETSUPPORT:
 153                         if (copy_to_user((struct watchdog_info *)arg, &ident,
 154                             sizeof(ident))) {
 155                                 return -EFAULT;
 156                         }
 157                         break;
 158                 case WDIOC_KEEPALIVE:
 159                         mixcomwd_ping();
 160                         break;
 161                 default:
 162                         return -ENOIOCTLCMD;
 163         }
 164         return 0;
 165 }
 166
 167 static struct file_operations mixcomwd_fops=
 168 {
 169         NULL,           /* Seek */
 170         NULL,           /* Read */
 171         mixcomwd_write, /* Write */
 172         NULL,           /* Readdir */
 173         NULL,           /* Select */
 174         mixcomwd_ioctl, /* Ioctl */
 175         NULL,           /* MMap */
 176         mixcomwd_open,
 177         NULL,           /* flush */
 178         mixcomwd_release,
 179         NULL,
 180         NULL            /* Fasync */
 181 };
 182
 183 static struct miscdevice mixcomwd_miscdev=
 184 {
 185         WATCHDOG_MINOR,
 186         "watchdog",
 187         &mixcomwd_fops
 188 };
 189
 190 static int __init mixcomwd_checkcard(int port)
 191 {
 192         int id;
 193
 194         if(check_region(port,1)) {
 195                 return 0;
 196         }
 197
 198         id=inb_p(port + MIXCOM_WATCHDOG_OFFSET) & 0x3f;
 199         if(id!=MIXCOM_ID1 && id!=MIXCOM_ID2) {
 200                 return 0;
 201         }
 202         return 1;
 203 }
 204
 205
 206 void __init mixcomwd_init(void)
 207 {
 208         int i;
 209         int found=0;
 210
 211         for (i = 0; mixcomwd_ioports[i] != 0; i++) {
 212                 if (mixcomwd_checkcard(mixcomwd_ioports[i])) {
 213                         found = 1;
 214                         mixcomwd_port = mixcomwd_ioports[i];
 215                         break;
 216                 }
 217         }
 218
 219         if (!found) {
 220                 printk("mixcomwd: No card detected, or port not available.\n");
 221                 return;
 222         }
 223
 224         request_region(mixcomwd_port+MIXCOM_WATCHDOG_OFFSET,1,"MixCOM watchdog");
 225
 226         misc_register(&mixcomwd_miscdev);
 227         printk("MixCOM watchdog driver v%s, MixCOM card at 0x%3x\n",VERSION,mixcomwd_port);
 228 }
 229
 230 #ifdef MODULE
 231 int init_module(void)
 232 {
 233         mixcomwd_init();
 234         return 0;
 235 }
 236
 237 void cleanup_module(void)
 238 {
 239 #ifndef CONFIG_WATCHDOG_NOWAYOUT
 240         if(mixcomwd_timer_alive) {
 241                 printk(KERN_WARNING "mixcomwd: I quit now, hardware will"
 242                         " probably reboot!\n");
 243                 del_timer(&mixcomwd_timer);
 244                 mixcomwd_timer_alive=0;
 245         }
 246 #endif
 247         release_region(mixcomwd_port+MIXCOM_WATCHDOG_OFFSET,1);
 248         misc_deregister(&mixcomwd_miscdev);
 249 }
 250 #endif