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 #include <linux/platform_device.h>
  29
  30 #define DRVNAME                 "ifxmips_wdt"
  31
  32 // TODO remove magic numbers and weirdo macros
  33 extern unsigned int ifxmips_get_fpi_hz (void);
  34
  35 static int ifxmips_wdt_inuse = 0;
  36 static int ifxmips_wdt_major = 0;
  37
  38 int
  39 ifxmips_wdt_enable (unsigned int timeout)
  40 {
  41         unsigned int wdt_cr = 0;
  42         unsigned int wdt_reload = 0;
  43         unsigned int wdt_clkdiv, wdt_pwl, ffpi;
  44         int retval = 0;
  45
  46         /* clock divider & prewarning limit */
  47         wdt_clkdiv = 1 << (7 * IFXMIPS_BIU_WDT_CR_CLKDIV_GET(readl(IFXMIPS_BIU_WDT_CR)));
  48         wdt_pwl = 0x8000 >> IFXMIPS_BIU_WDT_CR_PWL_GET(readl(IFXMIPS_BIU_WDT_CR));
  49
  50         //TODO
  51         printk("WARNING FUNCTION CALL MISSING!!!");
  52         //ffpi = cgu_get_io_region_clock();
  53         printk("cpu clock = %d\n", ffpi);
  54
  55         /* caculate reload value */
  56         wdt_reload = (timeout * (ffpi / wdt_clkdiv)) + wdt_pwl;
  57
  58         printk(KERN_WARNING DRVNAME ": wdt_pwl=0x%x, wdt_clkdiv=%d, ffpi=%d, wdt_reload = 0x%x\n",
  59                 wdt_pwl, wdt_clkdiv, ffpi, wdt_reload);
  60
  61         if (wdt_reload > 0xFFFF)
  62         {
  63                 printk(KERN_WARNING DRVNAME ": timeout too large %d\n", timeout);
  64                 retval = -EINVAL;
  65                 goto out;
  66         }
  67
  68         /* Write first part of password access */
  69         writel(IFXMIPS_BIU_WDT_CR_PW_SET(IFXMIPS_WDT_PW1), IFXMIPS_BIU_WDT_CR);
  70
  71         wdt_cr = readl(IFXMIPS_BIU_WDT_CR);
  72         wdt_cr &= (!IFXMIPS_BIU_WDT_CR_PW_SET(0xff) &
  73                    !IFXMIPS_BIU_WDT_CR_PWL_SET(0x3) &
  74                    !IFXMIPS_BIU_WDT_CR_CLKDIV_SET(0x3) &
  75                    !IFXMIPS_BIU_WDT_CR_RELOAD_SET(0xffff));
  76
  77         wdt_cr |= (IFXMIPS_BIU_WDT_CR_PW_SET(IFXMIPS_WDT_PW2) |
  78                    IFXMIPS_BIU_WDT_CR_PWL_SET(IFXMIPS_BIU_WDT_CR_PWL_GET(readl(IFXMIPS_BIU_WDT_CR))) |
  79                    IFXMIPS_BIU_WDT_CR_CLKDIV_SET(IFXMIPS_BIU_WDT_CR_CLKDIV_GET(readl(IFXMIPS_BIU_WDT_CR))) |
  80                    IFXMIPS_BIU_WDT_CR_RELOAD_SET(wdt_reload) |
  81                    IFXMIPS_BIU_WDT_CR_GEN);
  82
  83         writel(wdt_cr, IFXMIPS_BIU_WDT_CR);
  84
  85         printk("watchdog enabled\n");
  86
  87 out:
  88         return retval;
  89 }
  90
  91 void
  92 ifxmips_wdt_disable (void)
  93 {
  94         writel(IFXMIPS_BIU_WDT_CR_PW_SET(IFXMIPS_WDT_PW1), IFXMIPS_BIU_WDT_CR);
  95         writel(IFXMIPS_BIU_WDT_CR_PW_SET(IFXMIPS_WDT_PW2), IFXMIPS_BIU_WDT_CR);
  96
  97         printk("watchdog disabled\n");
  98 }
  99
 100 /* passed LPEN or DSEN */
 101 void
 102 ifxmips_wdt_enable_feature (int en, int type)
 103 {
 104         unsigned int wdt_cr = 0;
 105
 106         writel(IFXMIPS_BIU_WDT_CR_PW_SET(IFXMIPS_WDT_PW1), IFXMIPS_BIU_WDT_CR);
 107
 108         wdt_cr = readl(IFXMIPS_BIU_WDT_CR);
 109
 110         if (en)
 111         {
 112                 wdt_cr &= (~IFXMIPS_BIU_WDT_CR_PW_SET(0xff));
 113                 wdt_cr |= (IFXMIPS_BIU_WDT_CR_PW_SET(IFXMIPS_WDT_PW2) | type);
 114         } else {
 115                 wdt_cr &= (~IFXMIPS_BIU_WDT_CR_PW_SET(0xff) & ~type);
 116                 wdt_cr |= IFXMIPS_BIU_WDT_CR_PW_SET(IFXMIPS_WDT_PW2);
 117         }
 118
 119         writel(wdt_cr, IFXMIPS_BIU_WDT_CR);
 120 }
 121
 122 void
 123 ifxmips_wdt_prewarning_limit (int pwl)
 124 {
 125         unsigned int wdt_cr = 0;
 126
 127         wdt_cr = readl(IFXMIPS_BIU_WDT_CR);
 128         writel(IFXMIPS_BIU_WDT_CR_PW_SET(IFXMIPS_WDT_PW1), IFXMIPS_BIU_WDT_CR);
 129
 130         wdt_cr &= 0xf300ffff;
 131         wdt_cr |= (IFXMIPS_BIU_WDT_CR_PW_SET(IFXMIPS_WDT_PW2) | IFXMIPS_BIU_WDT_CR_PWL_SET(pwl));
 132
 133         /* Set reload value in second password access */
 134         writel(wdt_cr, IFXMIPS_BIU_WDT_CR);
 135 }
 136
 137 void
 138 ifxmips_wdt_set_clkdiv (int clkdiv)
 139 {
 140         unsigned int wdt_cr = 0;
 141
 142         wdt_cr = readl(IFXMIPS_BIU_WDT_CR);
 143         writel(IFXMIPS_BIU_WDT_CR_PW_SET(IFXMIPS_WDT_PW1), IFXMIPS_BIU_WDT_CR);
 144
 145         wdt_cr &= 0xfc00ffff;
 146         wdt_cr |= (IFXMIPS_BIU_WDT_CR_PW_SET(IFXMIPS_WDT_PW2) | IFXMIPS_BIU_WDT_CR_CLKDIV_SET(clkdiv));
 147
 148         /* Set reload value in second password access */
 149         writel(wdt_cr, IFXMIPS_BIU_WDT_CR);
 150 }
 151
 152 static int
 153 ifxmips_wdt_ioctl (struct inode *inode, struct file *file, unsigned int cmd,
 154            unsigned long arg)
 155 {
 156         int result = 0;
 157         static int timeout = -1;
 158         unsigned int user_arg;
 159
 160         if ((cmd != IFXMIPS_WDT_IOC_STOP) && (cmd != IFXMIPS_WDT_IOC_PING) && (cmd != IFXMIPS_WDT_IOC_GET_STATUS))
 161         {
 162                 if (copy_from_user((void *) &user_arg, (void *) arg, sizeof (int))){
 163                         result = -EINVAL;
 164                         goto out;
 165                 }
 166         }
 167
 168         switch (cmd)
 169         {
 170         case IFXMIPS_WDT_IOC_START:
 171                 if ((result = ifxmips_wdt_enable(user_arg)) < 0)
 172                         timeout = -1;
 173                 else
 174                         timeout = user_arg;
 175                 break;
 176
 177         case IFXMIPS_WDT_IOC_STOP:
 178                 printk(KERN_INFO DRVNAME ": disable watch dog timer\n");
 179                 ifxmips_wdt_disable();
 180                 break;
 181
 182         case IFXMIPS_WDT_IOC_PING:
 183                 if (timeout < 0)
 184                         result = -EIO;
 185                 else
 186                         result = ifxmips_wdt_enable(timeout);
 187                 break;
 188
 189         case IFXMIPS_WDT_IOC_GET_STATUS:
 190                 user_arg = readl(IFXMIPS_BIU_WDT_SR);
 191                 copy_to_user((int*)arg, (int*)&user_arg, sizeof(int));
 192                 break;
 193
 194         case IFXMIPS_WDT_IOC_SET_PWL:
 195                 ifxmips_wdt_prewarning_limit(user_arg);
 196                 break;
 197
 198         case IFXMIPS_WDT_IOC_SET_DSEN:
 199                 ifxmips_wdt_enable_feature(user_arg, IFXMIPS_BIU_WDT_CR_DSEN);
 200                 break;
 201
 202         case IFXMIPS_WDT_IOC_SET_LPEN:
 203                 ifxmips_wdt_enable_feature(user_arg, IFXMIPS_BIU_WDT_CR_LPEN);
 204                 break;
 205
 206         case IFXMIPS_WDT_IOC_SET_CLKDIV:
 207                 ifxmips_wdt_set_clkdiv(user_arg);
 208                 break;
 209
 210         default:
 211                 printk(KERN_WARNING DRVNAME ": unknown watchdog iotcl\n");
 212         }
 213
 214 out:
 215         return result;
 216 }
 217
 218 static int
 219 ifxmips_wdt_open (struct inode *inode, struct file *file)
 220 {
 221         if (ifxmips_wdt_inuse)
 222                 return -EBUSY;
 223
 224         ifxmips_wdt_inuse = 1;
 225
 226         return 0;
 227 }
 228
 229 static int
 230 ifxmips_wdt_release (struct inode *inode, struct file *file)
 231 {
 232         ifxmips_wdt_inuse = 0;
 233
 234         return 0;
 235 }
 236
 237 int
 238 ifxmips_wdt_register_proc_read (char *buf, char **start, off_t offset, int count,
 239                         int *eof, void *data)
 240 {
 241         int len = 0;
 242
 243         len += sprintf (buf + len, "IFXMIPS_BIU_WDT_PROC_READ\n");
 244         len += sprintf (buf + len, "IFXMIPS_BIU_WDT_CR(0x%08x)  : 0x%08x\n",
 245                         (unsigned int)IFXMIPS_BIU_WDT_CR, readl(IFXMIPS_BIU_WDT_CR));
 246         len += sprintf (buf + len, "IFXMIPS_BIU_WDT_SR(0x%08x)  : 0x%08x\n",
 247                         (unsigned int)IFXMIPS_BIU_WDT_SR, readl(IFXMIPS_BIU_WDT_SR));
 248
 249         *eof = 1;
 250
 251         return len;
 252 }
 253
 254 static struct file_operations wdt_fops = {
 255       .owner = THIS_MODULE,
 256       .ioctl = ifxmips_wdt_ioctl,
 257       .open = ifxmips_wdt_open,
 258       .release = ifxmips_wdt_release,
 259 };
 260
 261 static int
 262 ifxmips_wdt_probe (struct platform_device *pdev)
 263 {
 264         ifxmips_wdt_major = register_chrdev(0, "wdt", &wdt_fops);
 265
 266         if (ifxmips_wdt_major < 0)
 267         {
 268                 printk("cannot register watchdog device\n");
 269
 270                 return -EINVAL;
 271         }
 272
 273         create_proc_read_entry("ifxmips_wdt", 0, NULL, ifxmips_wdt_register_proc_read, NULL);
 274
 275         printk("ifxmips watchdog loaded\n");
 276
 277         return 0;
 278 }
 279
 280 static int
 281 ifxmips_wdt_remove (struct platform_device *pdev)
 282 {
 283         unregister_chrdev(ifxmips_wdt_major, "wdt");
 284         remove_proc_entry(DRVNAME, NULL);
 285         return 0;
 286 }
 287
 288 static struct
 289 platform_driver ifxmips_wdt_driver = {
 290         .probe = ifxmips_wdt_probe,
 291         .remove = ifxmips_wdt_remove,
 292         .driver = {
 293                 .name = DRVNAME,
 294                 .owner = THIS_MODULE,
 295         },
 296 };
 297
 298 int __init
 299 ifxmips_wdt_init_module (void)
 300 {
 301         int ret = platform_driver_register(&ifxmips_wdt_driver);
 302         if (ret)
 303                 printk(KERN_INFO DRVNAME ": Error registering platfom driver!");
 304         return ret;
 305 }
 306
 307 void
 308 ifxmips_wdt_cleanup_module (void)
 309 {
 310         platform_driver_unregister(&ifxmips_wdt_driver);
 311 }
 312
 313 module_init(ifxmips_wdt_init_module);
 314 module_exit(ifxmips_wdt_cleanup_module);