target/linux/ifxmips/files/drivers/char/watchdog/ifxmips_wdt.c

   1 /*
   2  *   This program is free software; you can redistribute it and/or modify
   3  *   it under the terms of the GNU General Public License as published by
   4  *   the Free Software Foundation; either version 2 of the License, or
   5  *   (at your option) any later version.
   6  *
   7  *   This program is distributed in the hope that it will be useful,
   8  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
   9  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  10  *   GNU General Public License for more details.
  11  *
  12  *   You should have received a copy of the GNU General Public License
  13  *   along with this program; if not, write to the Free Software
  14  *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307, USA.
  15  *
  16  *   Copyright (C) 2006 infineon
  17  *   Copyright (C) 2007 John Crispin <blogic@openwrt.org>
  18  *
  19  */
  20
  21 #include <asm/uaccess.h>
  22 #include <linux/errno.h>
  23 #include <linux/proc_fs.h>
  24 #include <linux/ioctl.h>
  25 #include <linux/module.h>
  26 #include <asm-mips/ifxmips/ifxmips_wdt.h>
  27 #include <asm-mips/ifxmips/ifxmips.h>
  28
  29
  30 // TODO remove magic numbers and weirdo macros
  31
  32 extern unsigned int ifxmips_get_fpi_hz (void);
  33
  34 static int ifxmips_wdt_inuse = 0;
  35 static int ifxmips_wdt_major = 0;
  36
  37 int
  38 ifxmips_wdt_enable (unsigned int timeout)
  39 {
  40         unsigned int wdt_cr = 0;
  41         unsigned int wdt_reload = 0;
  42         unsigned int wdt_clkdiv, wdt_pwl, ffpi;
  43         int retval = 0;
  44
  45         /* clock divider & prewarning limit */
  46         wdt_clkdiv = 1 << (7 * IFXMIPS_BIU_WDT_CR_CLKDIV_GET(readl(IFXMIPS_BIU_WDT_CR)));
  47         wdt_pwl = 0x8000 >> IFXMIPS_BIU_WDT_CR_PWL_GET(readl(IFXMIPS_BIU_WDT_CR));
  48
  49         //TODO
  50         printk("WARNING FUNCTION CALL MISSING!!!");
  51         //ffpi = cgu_get_io_region_clock();
  52         printk("cpu clock = %d\n", ffpi);
  53
  54         /* caculate reload value */
  55         wdt_reload = (timeout * (ffpi / wdt_clkdiv)) + wdt_pwl;
  56
  57         printk("wdt_pwl=0x%x, wdt_clkdiv=%d, ffpi=%d, wdt_reload = 0x%x\n",
  58                 wdt_pwl, wdt_clkdiv, ffpi, wdt_reload);
  59
  60         if (wdt_reload > 0xFFFF)
  61         {
  62                 printk ("timeout too large %d\n", timeout);
  63                 retval = -EINVAL;
  64                 goto out;
  65         }
  66
  67         /* Write first part of password access */
  68         writel(IFXMIPS_BIU_WDT_CR_PW_SET(IFXMIPS_WDT_PW1), IFXMIPS_BIU_WDT_CR);
  69
  70         wdt_cr = readl(IFXMIPS_BIU_WDT_CR);
  71         wdt_cr &= (!IFXMIPS_BIU_WDT_CR_PW_SET(0xff) &
  72                    !IFXMIPS_BIU_WDT_CR_PWL_SET(0x3) &
  73                    !IFXMIPS_BIU_WDT_CR_CLKDIV_SET(0x3) &
  74                    !IFXMIPS_BIU_WDT_CR_RELOAD_SET(0xffff));
  75
  76         wdt_cr |= (IFXMIPS_BIU_WDT_CR_PW_SET(IFXMIPS_WDT_PW2) |
  77                    IFXMIPS_BIU_WDT_CR_PWL_SET(IFXMIPS_BIU_WDT_CR_PWL_GET(readl(IFXMIPS_BIU_WDT_CR))) |
  78                    IFXMIPS_BIU_WDT_CR_CLKDIV_SET(IFXMIPS_BIU_WDT_CR_CLKDIV_GET(readl(IFXMIPS_BIU_WDT_CR))) |
  79                    IFXMIPS_BIU_WDT_CR_RELOAD_SET(wdt_reload) |
  80                    IFXMIPS_BIU_WDT_CR_GEN);
  81
  82         writel(wdt_cr, IFXMIPS_BIU_WDT_CR);
  83
  84         printk("watchdog enabled\n");
  85
  86 out:
  87         return retval;
  88 }
  89
  90 void
  91 ifxmips_wdt_disable (void)
  92 {
  93         writel(IFXMIPS_BIU_WDT_CR_PW_SET(IFXMIPS_WDT_PW1), IFXMIPS_BIU_WDT_CR);
  94         writel(IFXMIPS_BIU_WDT_CR_PW_SET(IFXMIPS_WDT_PW2), IFXMIPS_BIU_WDT_CR);
  95
  96         printk("watchdog disabled\n");
  97 }
  98
  99 /* passed LPEN or DSEN */
 100 void
 101 ifxmips_wdt_enable_feature (int en, int type)
 102 {
 103         unsigned int wdt_cr = 0;
 104
 105         writel(IFXMIPS_BIU_WDT_CR_PW_SET(IFXMIPS_WDT_PW1), IFXMIPS_BIU_WDT_CR);
 106
 107         wdt_cr = readl(IFXMIPS_BIU_WDT_CR);
 108
 109         if (en)
 110         {
 111                 wdt_cr &= (~IFXMIPS_BIU_WDT_CR_PW_SET(0xff));
 112                 wdt_cr |= (IFXMIPS_BIU_WDT_CR_PW_SET(IFXMIPS_WDT_PW2) | type);
 113         } else {
 114                 wdt_cr &= (~IFXMIPS_BIU_WDT_CR_PW_SET(0xff) & ~type);
 115                 wdt_cr |= IFXMIPS_BIU_WDT_CR_PW_SET(IFXMIPS_WDT_PW2);
 116         }
 117
 118         writel(wdt_cr, IFXMIPS_BIU_WDT_CR);
 119 }
 120
 121 void
 122 ifxmips_wdt_prewarning_limit (int pwl)
 123 {
 124         unsigned int wdt_cr = 0;
 125
 126         wdt_cr = readl(IFXMIPS_BIU_WDT_CR);
 127         writel(IFXMIPS_BIU_WDT_CR_PW_SET(IFXMIPS_WDT_PW1), IFXMIPS_BIU_WDT_CR);
 128
 129         wdt_cr &= 0xf300ffff;
 130         wdt_cr |= (IFXMIPS_BIU_WDT_CR_PW_SET(IFXMIPS_WDT_PW2) | IFXMIPS_BIU_WDT_CR_PWL_SET(pwl));
 131
 132         /* Set reload value in second password access */
 133         writel(wdt_cr, IFXMIPS_BIU_WDT_CR);
 134 }
 135
 136 void
 137 ifxmips_wdt_set_clkdiv (int clkdiv)
 138 {
 139         unsigned int wdt_cr = 0;
 140
 141         wdt_cr = readl(IFXMIPS_BIU_WDT_CR);
 142         writel(IFXMIPS_BIU_WDT_CR_PW_SET(IFXMIPS_WDT_PW1), IFXMIPS_BIU_WDT_CR);
 143
 144         wdt_cr &= 0xfc00ffff;
 145         wdt_cr |= (IFXMIPS_BIU_WDT_CR_PW_SET(IFXMIPS_WDT_PW2) | IFXMIPS_BIU_WDT_CR_CLKDIV_SET(clkdiv));
 146
 147         /* Set reload value in second password access */
 148         writel(wdt_cr, IFXMIPS_BIU_WDT_CR);
 149 }
 150
 151 static int
 152 ifxmips_wdt_ioctl (struct inode *inode, struct file *file, unsigned int cmd,
 153            unsigned long arg)
 154 {
 155         int result = 0;
 156         static int timeout = -1;
 157         unsigned int user_arg;
 158
 159         if ((cmd != IFXMIPS_WDT_IOC_STOP) && (cmd != IFXMIPS_WDT_IOC_PING) && (cmd != IFXMIPS_WDT_IOC_GET_STATUS))
 160         {
 161                 if (copy_from_user((void *) &user_arg, (void *) arg, sizeof (int))){
 162                         result = -EINVAL;
 163                         goto out;
 164                 }
 165         }
 166
 167         switch (cmd)
 168         {
 169         case IFXMIPS_WDT_IOC_START:
 170                 if ((result = ifxmips_wdt_enable(user_arg)) < 0)
 171                         timeout = -1;
 172                 else
 173                         timeout = user_arg;
 174                 break;
 175
 176         case IFXMIPS_WDT_IOC_STOP:
 177                 printk("disable watch dog timer\n");
 178                 ifxmips_wdt_disable();
 179                 break;
 180
 181         case IFXMIPS_WDT_IOC_PING:
 182                 if (timeout < 0)
 183                         result = -EIO;
 184                 else
 185                         result = ifxmips_wdt_enable(timeout);
 186                 break;
 187
 188         case IFXMIPS_WDT_IOC_GET_STATUS:
 189                 user_arg = readl(IFXMIPS_BIU_WDT_SR);
 190                 copy_to_user((int*)arg, (int*)&user_arg, sizeof(int));
 191                 break;
 192
 193         case IFXMIPS_WDT_IOC_SET_PWL:
 194                 ifxmips_wdt_prewarning_limit(user_arg);
 195                 break;
 196
 197         case IFXMIPS_WDT_IOC_SET_DSEN:
 198                 ifxmips_wdt_enable_feature(user_arg, IFXMIPS_BIU_WDT_CR_DSEN);
 199                 break;
 200
 201         case IFXMIPS_WDT_IOC_SET_LPEN:
 202                 ifxmips_wdt_enable_feature(user_arg, IFXMIPS_BIU_WDT_CR_LPEN);
 203                 break;
 204
 205         case IFXMIPS_WDT_IOC_SET_CLKDIV:
 206                 ifxmips_wdt_set_clkdiv(user_arg);
 207                 break;
 208
 209         default:
 210                 printk("unknown watchdog iotcl\n");
 211         }
 212
 213 out:
 214         return result;
 215 }
 216
 217 static int
 218 ifxmips_wdt_open (struct inode *inode, struct file *file)
 219 {
 220         if (ifxmips_wdt_inuse)
 221                 return -EBUSY;
 222
 223         ifxmips_wdt_inuse = 1;
 224
 225         return 0;
 226 }
 227
 228 static int
 229 ifxmips_wdt_release (struct inode *inode, struct file *file)
 230 {
 231         ifxmips_wdt_inuse = 0;
 232
 233         return 0;
 234 }
 235
 236 int
 237 ifxmips_wdt_register_proc_read (char *buf, char **start, off_t offset, int count,
 238                         int *eof, void *data)
 239 {
 240         int len = 0;
 241
 242         len += sprintf (buf + len, "IFXMIPS_BIU_WDT_PROC_READ\n");
 243         len += sprintf (buf + len, "IFXMIPS_BIU_WDT_CR(0x%08x)  : 0x%08x\n",
 244                         (unsigned int)IFXMIPS_BIU_WDT_CR, readl(IFXMIPS_BIU_WDT_CR));
 245         len += sprintf (buf + len, "IFXMIPS_BIU_WDT_SR(0x%08x)  : 0x%08x\n",
 246                         (unsigned int)IFXMIPS_BIU_WDT_SR, readl(IFXMIPS_BIU_WDT_SR));
 247
 248         *eof = 1;
 249
 250         return len;
 251 }
 252
 253 static struct file_operations wdt_fops = {
 254       .owner = THIS_MODULE,
 255       .ioctl = ifxmips_wdt_ioctl,
 256       .open = ifxmips_wdt_open,
 257       .release = ifxmips_wdt_release,
 258 };
 259
 260 int __init
 261 ifxmips_wdt_init_module (void)
 262 {
 263         ifxmips_wdt_major = register_chrdev(0, "wdt", &wdt_fops);
 264
 265         if (ifxmips_wdt_major < 0)
 266         {
 267                 printk("cannot register watchdog device\n");
 268
 269                 return -EINVAL;
 270         }
 271
 272         create_proc_read_entry("ifxmips_wdt", 0, NULL, ifxmips_wdt_register_proc_read, NULL);
 273
 274         printk("ifxmips watchdog loaded\n");
 275
 276         return 0;
 277 }
 278
 279 void
 280 ifxmips_wdt_cleanup_module (void)
 281 {
 282         unregister_chrdev(ifxmips_wdt_major, "wdt");
 283         remove_proc_entry("ifxmips_wdt", NULL);
 284 }
 285
 286 module_init(ifxmips_wdt_init_module);
 287 module_exit(ifxmips_wdt_cleanup_module);