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 <linux/platform_device.h>
  27 #include <linux/watchdog.h>
  28 #include <linux/miscdevice.h>
  29 #include <asm-mips/ifxmips/ifxmips_wdt.h>
  30 #include <asm-mips/ifxmips/ifxmips.h>
  31
  32 #define DRVNAME                 "ifxmips_wdt"
  33
  34 // TODO remove magic numbers and weirdo macros
  35 extern unsigned int ifxmips_get_fpi_hz (void);
  36
  37 static int ifxmips_wdt_inuse = 0;
  38 static int ifxmips_wdt_major = 0;
  39
  40 int
  41 ifxmips_wdt_enable (unsigned int timeout)
  42 {
  43         unsigned int wdt_cr = 0;
  44         unsigned int wdt_reload = 0;
  45         unsigned int wdt_clkdiv, wdt_pwl, ffpi;
  46         int retval = 0;
  47
  48         /* clock divider & prewarning limit */
  49         wdt_clkdiv = 1 << (7 * IFXMIPS_BIU_WDT_CR_CLKDIV_GET(readl(IFXMIPS_BIU_WDT_CR)));
  50         wdt_pwl = 0x8000 >> IFXMIPS_BIU_WDT_CR_PWL_GET(readl(IFXMIPS_BIU_WDT_CR));
  51
  52         //TODO
  53         printk("WARNING FUNCTION CALL MISSING!!!");
  54         //ffpi = cgu_get_io_region_clock();
  55         printk("cpu clock = %d\n", ffpi);
  56
  57         /* caculate reload value */
  58         wdt_reload = (timeout * (ffpi / wdt_clkdiv)) + wdt_pwl;
  59
  60         printk(KERN_WARNING DRVNAME ": wdt_pwl=0x%x, wdt_clkdiv=%d, ffpi=%d, wdt_reload = 0x%x\n",
  61                 wdt_pwl, wdt_clkdiv, ffpi, wdt_reload);
  62
  63         if (wdt_reload > 0xFFFF)
  64         {
  65                 printk(KERN_WARNING DRVNAME ": timeout too large %d\n", timeout);
  66                 retval = -EINVAL;
  67                 goto out;
  68         }
  69
  70         /* Write first part of password access */
  71         writel(IFXMIPS_BIU_WDT_CR_PW_SET(IFXMIPS_WDT_PW1), IFXMIPS_BIU_WDT_CR);
  72
  73         wdt_cr = readl(IFXMIPS_BIU_WDT_CR);
  74         wdt_cr &= (!IFXMIPS_BIU_WDT_CR_PW_SET(0xff) &
  75                    !IFXMIPS_BIU_WDT_CR_PWL_SET(0x3) &
  76                    !IFXMIPS_BIU_WDT_CR_CLKDIV_SET(0x3) &
  77                    !IFXMIPS_BIU_WDT_CR_RELOAD_SET(0xffff));
  78
  79         wdt_cr |= (IFXMIPS_BIU_WDT_CR_PW_SET(IFXMIPS_WDT_PW2) |
  80                    IFXMIPS_BIU_WDT_CR_PWL_SET(IFXMIPS_BIU_WDT_CR_PWL_GET(readl(IFXMIPS_BIU_WDT_CR))) |
  81                    IFXMIPS_BIU_WDT_CR_CLKDIV_SET(IFXMIPS_BIU_WDT_CR_CLKDIV_GET(readl(IFXMIPS_BIU_WDT_CR))) |
  82                    IFXMIPS_BIU_WDT_CR_RELOAD_SET(wdt_reload) |
  83                    IFXMIPS_BIU_WDT_CR_GEN);
  84
  85         writel(wdt_cr, IFXMIPS_BIU_WDT_CR);
  86
  87         printk("watchdog enabled\n");
  88
  89 out:
  90         return retval;
  91 }
  92
  93 void
  94 ifxmips_wdt_disable (void)
  95 {
  96         writel(IFXMIPS_BIU_WDT_CR_PW_SET(IFXMIPS_WDT_PW1), IFXMIPS_BIU_WDT_CR);
  97         writel(IFXMIPS_BIU_WDT_CR_PW_SET(IFXMIPS_WDT_PW2), IFXMIPS_BIU_WDT_CR);
  98
  99         printk("watchdog disabled\n");
 100 }
 101
 102 /* passed LPEN or DSEN */
 103 void
 104 ifxmips_wdt_enable_feature (int en, int type)
 105 {
 106         unsigned int wdt_cr = 0;
 107
 108         writel(IFXMIPS_BIU_WDT_CR_PW_SET(IFXMIPS_WDT_PW1), IFXMIPS_BIU_WDT_CR);
 109
 110         wdt_cr = readl(IFXMIPS_BIU_WDT_CR);
 111
 112         if (en)
 113         {
 114                 wdt_cr &= (~IFXMIPS_BIU_WDT_CR_PW_SET(0xff));
 115                 wdt_cr |= (IFXMIPS_BIU_WDT_CR_PW_SET(IFXMIPS_WDT_PW2) | type);
 116         } else {
 117                 wdt_cr &= (~IFXMIPS_BIU_WDT_CR_PW_SET(0xff) & ~type);
 118                 wdt_cr |= IFXMIPS_BIU_WDT_CR_PW_SET(IFXMIPS_WDT_PW2);
 119         }
 120
 121         writel(wdt_cr, IFXMIPS_BIU_WDT_CR);
 122 }
 123
 124 void
 125 ifxmips_wdt_prewarning_limit (int pwl)
 126 {
 127         unsigned int wdt_cr = 0;
 128
 129         wdt_cr = readl(IFXMIPS_BIU_WDT_CR);
 130         writel(IFXMIPS_BIU_WDT_CR_PW_SET(IFXMIPS_WDT_PW1), IFXMIPS_BIU_WDT_CR);
 131
 132         wdt_cr &= 0xf300ffff;
 133         wdt_cr |= (IFXMIPS_BIU_WDT_CR_PW_SET(IFXMIPS_WDT_PW2) | IFXMIPS_BIU_WDT_CR_PWL_SET(pwl));
 134
 135         /* Set reload value in second password access */
 136         writel(wdt_cr, IFXMIPS_BIU_WDT_CR);
 137 }
 138
 139 void
 140 ifxmips_wdt_set_clkdiv (int clkdiv)
 141 {
 142         unsigned int wdt_cr = 0;
 143
 144         wdt_cr = readl(IFXMIPS_BIU_WDT_CR);
 145         writel(IFXMIPS_BIU_WDT_CR_PW_SET(IFXMIPS_WDT_PW1), IFXMIPS_BIU_WDT_CR);
 146
 147         wdt_cr &= 0xfc00ffff;
 148         wdt_cr |= (IFXMIPS_BIU_WDT_CR_PW_SET(IFXMIPS_WDT_PW2) | IFXMIPS_BIU_WDT_CR_CLKDIV_SET(clkdiv));
 149
 150         /* Set reload value in second password access */
 151         writel(wdt_cr, IFXMIPS_BIU_WDT_CR);
 152 }
 153
 154 static int
 155 ifxmips_wdt_ioctl (struct inode *inode, struct file *file, unsigned int cmd,
 156            unsigned long arg)
 157 {
 158         int result = 0;
 159         static int timeout = -1;
 160         unsigned int user_arg;
 161
 162         if ((cmd != IFXMIPS_WDT_IOC_STOP) && (cmd != IFXMIPS_WDT_IOC_PING) && (cmd != IFXMIPS_WDT_IOC_GET_STATUS))
 163         {
 164                 if (copy_from_user((void *) &user_arg, (void *) arg, sizeof (int))){
 165                         result = -EINVAL;
 166                         goto out;
 167                 }
 168         }
 169
 170         switch (cmd)
 171         {
 172         case IFXMIPS_WDT_IOC_START:
 173                 if ((result = ifxmips_wdt_enable(user_arg)) < 0)
 174                         timeout = -1;
 175                 else
 176                         timeout = user_arg;
 177                 break;
 178
 179         case IFXMIPS_WDT_IOC_STOP:
 180                 printk(KERN_INFO DRVNAME ": disable watch dog timer\n");
 181                 ifxmips_wdt_disable();
 182                 break;
 183
 184         case IFXMIPS_WDT_IOC_PING:
 185                 if (timeout < 0)
 186                         result = -EIO;
 187                 else
 188                         result = ifxmips_wdt_enable(timeout);
 189                 break;
 190
 191         case IFXMIPS_WDT_IOC_GET_STATUS:
 192                 user_arg = readl(IFXMIPS_BIU_WDT_SR);
 193                 copy_to_user((int*)arg, (int*)&user_arg, sizeof(int));
 194                 break;
 195
 196         case IFXMIPS_WDT_IOC_SET_PWL:
 197                 ifxmips_wdt_prewarning_limit(user_arg);
 198                 break;
 199
 200         case IFXMIPS_WDT_IOC_SET_DSEN:
 201                 ifxmips_wdt_enable_feature(user_arg, IFXMIPS_BIU_WDT_CR_DSEN);
 202                 break;
 203
 204         case IFXMIPS_WDT_IOC_SET_LPEN:
 205                 ifxmips_wdt_enable_feature(user_arg, IFXMIPS_BIU_WDT_CR_LPEN);
 206                 break;
 207
 208         case IFXMIPS_WDT_IOC_SET_CLKDIV:
 209                 ifxmips_wdt_set_clkdiv(user_arg);
 210                 break;
 211
 212         default:
 213                 printk(KERN_WARNING DRVNAME ": unknown watchdog iotcl\n");
 214         }
 215
 216 out:
 217         return result;
 218 }
 219
 220 static int
 221 ifxmips_wdt_open (struct inode *inode, struct file *file)
 222 {
 223         if (ifxmips_wdt_inuse)
 224                 return -EBUSY;
 225
 226         ifxmips_wdt_inuse = 1;
 227
 228         return 0;
 229 }
 230
 231 static int
 232 ifxmips_wdt_release (struct inode *inode, struct file *file)
 233 {
 234         ifxmips_wdt_inuse = 0;
 235
 236         return 0;
 237 }
 238
 239 int
 240 ifxmips_wdt_register_proc_read (char *buf, char **start, off_t offset, int count,
 241                         int *eof, void *data)
 242 {
 243         int len = 0;
 244
 245         len += sprintf (buf + len, "IFXMIPS_BIU_WDT_PROC_READ\n");
 246         len += sprintf (buf + len, "IFXMIPS_BIU_WDT_CR(0x%08x)  : 0x%08x\n",
 247                         (unsigned int)IFXMIPS_BIU_WDT_CR, readl(IFXMIPS_BIU_WDT_CR));
 248         len += sprintf (buf + len, "IFXMIPS_BIU_WDT_SR(0x%08x)  : 0x%08x\n",
 249                         (unsigned int)IFXMIPS_BIU_WDT_SR, readl(IFXMIPS_BIU_WDT_SR));
 250
 251         *eof = 1;
 252
 253         return len;
 254 }
 255
 256 static const struct file_operations ifxmips_wdt_fops = {
 257         .owner          = THIS_MODULE,
 258         .llseek         = no_llseek,
 259         .ioctl          = ifxmips_wdt_ioctl,
 260         .open           = ifxmips_wdt_open,
 261         .release        = ifxmips_wdt_release,
 262 //      .write          = at91_wdt_write,
 263 };
 264
 265 static struct miscdevice ifxmips_wdt_miscdev = {
 266         .minor          = WATCHDOG_MINOR,
 267         .name           = "ifxmips_wdt",
 268         .fops           = &ifxmips_wdt_fops,
 269 };
 270
 271
 272 static int
 273 ifxmips_wdt_probe (struct platform_device *pdev)
 274 {
 275         int ret = misc_register(&ifxmips_wdt_miscdev);
 276         if (ret)
 277                 return ret;
 278
 279         create_proc_read_entry(DRVNAME, 0, NULL, ifxmips_wdt_register_proc_read, NULL);
 280
 281         printk(KERN_INFO DRVNAME ": ifxmips watchdog loaded\n");
 282
 283         return 0;
 284 }
 285
 286 static int
 287 ifxmips_wdt_remove (struct platform_device *pdev)
 288 {
 289         misc_deregister(&ifxmips_wdt_miscdev);
 290         remove_proc_entry(DRVNAME, NULL);
 291         return 0;
 292 }
 293
 294 static struct
 295 platform_driver ifxmips_wdt_driver = {
 296         .probe = ifxmips_wdt_probe,
 297         .remove = ifxmips_wdt_remove,
 298         .driver = {
 299                 .name = DRVNAME,
 300                 .owner = THIS_MODULE,
 301         },
 302 };
 303
 304 int __init
 305 ifxmips_wdt_init_module (void)
 306 {
 307         int ret = platform_driver_register(&ifxmips_wdt_driver);
 308         if (ret)
 309                 printk(KERN_INFO DRVNAME ": Error registering platfom driver!");
 310         return ret;
 311 }
 312
 313 void
 314 ifxmips_wdt_cleanup_module (void)
 315 {
 316         platform_driver_unregister(&ifxmips_wdt_driver);
 317 }
 318
 319 module_init(ifxmips_wdt_init_module);
 320 module_exit(ifxmips_wdt_cleanup_module);
 321
 322 MODULE_AUTHOR("John Crispin <blogic@openwrt.org>");
 323 MODULE_DESCRIPTION("Watchdog driver for infineon ifxmips family");
 324 MODULE_LICENSE("GPL");
 325 MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);