target/linux/brcm47xx/patches-2.6.28/815-watchdog.patch

   1 This add watchdog driver for broadcom 47xx device.
   2 It uses the ssb subsytem to access embeded watchdog device.
   3
   4 Because the watchdog timeout is very short (about 2s), a soft timer is used
   5 to increase the watchdog period.
   6
   7 Note : A patch for exporting the ssb_watchdog_timer_set will
   8 be submitted on next linux-mips merge. Without this patch it can't
   9 be build as a module.
  10
  11 Signed-off-by: Aleksandar Radovanovic <biblbroks@sezampro.rs>
  12 Signed-off-by: Matthieu CASTET <castet.matthieu@free.fr>
  13 --- a/drivers/watchdog/Kconfig
  14 +++ b/drivers/watchdog/Kconfig
  15 @@ -747,6 +747,12 @@ config TXX9_WDT
  16         help
  17           Hardware driver for the built-in watchdog timer on TXx9 MIPS SoCs.
  18
  19 +config BCM47XX_WDT
  20 +       tristate "Broadcom BCM47xx Watchdog Timer"
  21 +       depends on BCM47XX
  22 +       help
  23 +         Hardware driver for the Broadcom BCM47xx Watchog Timer.
  24 +
  25  # PARISC Architecture
  26
  27  # POWERPC Architecture
  28 --- a/drivers/watchdog/Makefile
  29 +++ b/drivers/watchdog/Makefile
  30 @@ -106,6 +106,7 @@ obj-$(CONFIG_WDT_RM9K_GPI) += rm9k_wdt.o
  31  obj-$(CONFIG_SIBYTE_WDOG) += sb_wdog.o
  32  obj-$(CONFIG_AR7_WDT) += ar7_wdt.o
  33  obj-$(CONFIG_TXX9_WDT) += txx9wdt.o
  34 +obj-$(CONFIG_BCM47XX_WDT) += bcm47xx_wdt.o
  35
  36  # PARISC Architecture
  37
  38 --- /dev/null
  39 +++ b/drivers/watchdog/bcm47xx_wdt.c
  40 @@ -0,0 +1,286 @@
  41 +/*
  42 + *  Watchdog driver for Broadcom BCM47XX
  43 + *
  44 + *  Copyright (C) 2008 Aleksandar Radovanovic <biblbroks@sezampro.rs>
  45 + *  Copyright (C) 2009 Matthieu CASTET <castet.matthieu@free.fr>
  46 + *
  47 + *  This program is free software; you can redistribute it and/or
  48 + *  modify it under the terms of the GNU General Public License
  49 + *  as published by the Free Software Foundation; either version
  50 + *  2 of the License, or (at your option) any later version.
  51 + */
  52 +
  53 +#include <linux/bitops.h>
  54 +#include <linux/errno.h>
  55 +#include <linux/fs.h>
  56 +#include <linux/init.h>
  57 +#include <linux/kernel.h>
  58 +#include <linux/miscdevice.h>
  59 +#include <linux/module.h>
  60 +#include <linux/moduleparam.h>
  61 +#include <linux/reboot.h>
  62 +#include <linux/types.h>
  63 +#include <linux/uaccess.h>
  64 +#include <linux/watchdog.h>
  65 +#include <linux/timer.h>
  66 +#include <linux/jiffies.h>
  67 +#include <linux/ssb/ssb_embedded.h>
  68 +#include <asm/mach-bcm47xx/bcm47xx.h>
  69 +
  70 +#define DRV_NAME               "bcm47xx_wdt"
  71 +
  72 +#define WDT_DEFAULT_TIME       30      /* seconds */
  73 +#define WDT_MAX_TIME           256     /* seconds */
  74 +
  75 +static int wdt_time = WDT_DEFAULT_TIME;
  76 +static int nowayout = WATCHDOG_NOWAYOUT;
  77 +
  78 +module_param(wdt_time, int, 0);
  79 +MODULE_PARM_DESC(wdt_time, "Watchdog time in seconds. (default="
  80 +                               __MODULE_STRING(WDT_DEFAULT_TIME) ")");
  81 +
  82 +#ifdef CONFIG_WATCHDOG_NOWAYOUT
  83 +module_param(nowayout, int, 0);
  84 +MODULE_PARM_DESC(nowayout,
  85 +               "Watchdog cannot be stopped once started (default="
  86 +                               __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
  87 +#endif
  88 +
  89 +static unsigned long bcm47xx_wdt_busy;
  90 +static char expect_release;
  91 +static struct timer_list wdt_timer;
  92 +static atomic_t ticks;
  93 +
  94 +static inline void bcm47xx_wdt_hw_start(void)
  95 +{
  96 +       /* this is 2,5s on 100Mhz clock  and 2s on 133 Mhz */
  97 +       ssb_watchdog_timer_set(&ssb_bcm47xx, 0xfffffff);
  98 +}
  99 +
 100 +static inline int bcm47xx_wdt_hw_stop(void)
 101 +{
 102 +       return ssb_watchdog_timer_set(&ssb_bcm47xx, 0);
 103 +}
 104 +
 105 +static void bcm47xx_timer_tick(unsigned long unused)
 106 +{
 107 +       if (!atomic_dec_and_test(&ticks)) {
 108 +               bcm47xx_wdt_hw_start();
 109 +               mod_timer(&wdt_timer, jiffies + HZ);
 110 +       } else {
 111 +               printk(KERN_CRIT DRV_NAME "Watchdog will fire soon!!!\n");
 112 +       }
 113 +}
 114 +
 115 +static inline void bcm47xx_wdt_pet(void)
 116 +{
 117 +       atomic_set(&ticks, wdt_time);
 118 +}
 119 +
 120 +static void bcm47xx_wdt_start(void)
 121 +{
 122 +       bcm47xx_wdt_pet();
 123 +       bcm47xx_timer_tick(0);
 124 +}
 125 +
 126 +static void bcm47xx_wdt_pause(void)
 127 +{
 128 +       del_timer_sync(&wdt_timer);
 129 +       bcm47xx_wdt_hw_stop();
 130 +}
 131 +
 132 +static void bcm47xx_wdt_stop(void)
 133 +{
 134 +       bcm47xx_wdt_pause();
 135 +}
 136 +
 137 +static int bcm47xx_wdt_settimeout(int new_time)
 138 +{
 139 +       if ((new_time <= 0) || (new_time > WDT_MAX_TIME))
 140 +               return -EINVAL;
 141 +
 142 +       wdt_time = new_time;
 143 +       return 0;
 144 +}
 145 +
 146 +static int bcm47xx_wdt_open(struct inode *inode, struct file *file)
 147 +{
 148 +       if (test_and_set_bit(0, &bcm47xx_wdt_busy))
 149 +               return -EBUSY;
 150 +
 151 +       bcm47xx_wdt_start();
 152 +       return nonseekable_open(inode, file);
 153 +}
 154 +
 155 +static int bcm47xx_wdt_release(struct inode *inode, struct file *file)
 156 +{
 157 +       if (expect_release == 42) {
 158 +               bcm47xx_wdt_stop();
 159 +       } else {
 160 +               printk(KERN_CRIT DRV_NAME
 161 +                       ": Unexpected close, not stopping watchdog!\n");
 162 +               bcm47xx_wdt_start();
 163 +       }
 164 +
 165 +       clear_bit(0, &bcm47xx_wdt_busy);
 166 +       expect_release = 0;
 167 +       return 0;
 168 +}
 169 +
 170 +static ssize_t bcm47xx_wdt_write(struct file *file, const char __user *data,
 171 +                             size_t len, loff_t *ppos)
 172 +{
 173 +       if (len) {
 174 +               if (!nowayout) {
 175 +                       size_t i;
 176 +
 177 +                       expect_release = 0;
 178 +
 179 +                       for (i = 0; i != len; i++) {
 180 +                               char c;
 181 +                               if (get_user(c, data + i))
 182 +                                       return -EFAULT;
 183 +                               if (c == 'V')
 184 +                                       expect_release = 42;
 185 +                       }
 186 +               }
 187 +               bcm47xx_wdt_pet();
 188 +       }
 189 +       return len;
 190 +}
 191 +
 192 +static struct watchdog_info bcm47xx_wdt_info = {
 193 +       .identity       = DRV_NAME,
 194 +       .options        = WDIOF_SETTIMEOUT |
 195 +                               WDIOF_KEEPALIVEPING |
 196 +                               WDIOF_MAGICCLOSE,
 197 +};
 198 +
 199 +static long bcm47xx_wdt_ioctl(struct file *file,
 200 +                                       unsigned int cmd, unsigned long arg)
 201 +{
 202 +       void __user *argp = (void __user *)arg;
 203 +       int __user *p = argp;
 204 +       int new_value, retval = -EINVAL;;
 205 +
 206 +       switch (cmd) {
 207 +       case WDIOC_GETSUPPORT:
 208 +               return copy_to_user(argp, &bcm47xx_wdt_info,
 209 +                               sizeof(bcm47xx_wdt_info)) ? -EFAULT : 0;
 210 +
 211 +       case WDIOC_GETSTATUS:
 212 +       case WDIOC_GETBOOTSTATUS:
 213 +               return put_user(0, p);
 214 +
 215 +       case WDIOC_SETOPTIONS:
 216 +               if (get_user(new_value, p))
 217 +                       return -EFAULT;
 218 +
 219 +               if (new_value & WDIOS_DISABLECARD) {
 220 +                       bcm47xx_wdt_stop();
 221 +                       retval = 0;
 222 +               }
 223 +
 224 +               if (new_value & WDIOS_ENABLECARD) {
 225 +                       bcm47xx_wdt_start();
 226 +                       retval = 0;
 227 +               }
 228 +
 229 +               return retval;
 230 +
 231 +       case WDIOC_KEEPALIVE:
 232 +               bcm47xx_wdt_pet();
 233 +               return 0;
 234 +
 235 +       case WDIOC_SETTIMEOUT:
 236 +               if (get_user(new_value, p))
 237 +                       return -EFAULT;
 238 +
 239 +               if (bcm47xx_wdt_settimeout(new_value))
 240 +                       return -EINVAL;
 241 +
 242 +               bcm47xx_wdt_pet();
 243 +
 244 +       case WDIOC_GETTIMEOUT:
 245 +               return put_user(wdt_time, p);
 246 +
 247 +       default:
 248 +               return -ENOTTY;
 249 +       }
 250 +}
 251 +
 252 +static int bcm47xx_wdt_notify_sys(struct notifier_block *this,
 253 +          unsigned long code, void *unused)
 254 +{
 255 +       if (code == SYS_DOWN || code == SYS_HALT)
 256 +               bcm47xx_wdt_stop();
 257 +       return NOTIFY_DONE;
 258 +}
 259 +
 260 +static const struct file_operations bcm47xx_wdt_fops = {
 261 +       .owner          = THIS_MODULE,
 262 +       .llseek         = no_llseek,
 263 +       .unlocked_ioctl = bcm47xx_wdt_ioctl,
 264 +       .open           = bcm47xx_wdt_open,
 265 +       .release        = bcm47xx_wdt_release,
 266 +       .write          = bcm47xx_wdt_write,
 267 +};
 268 +
 269 +static struct miscdevice bcm47xx_wdt_miscdev = {
 270 +       .minor          = WATCHDOG_MINOR,
 271 +       .name           = "watchdog",
 272 +       .fops           = &bcm47xx_wdt_fops,
 273 +};
 274 +
 275 +static struct notifier_block bcm47xx_wdt_notifier = {
 276 +       .notifier_call = bcm47xx_wdt_notify_sys,
 277 +};
 278 +
 279 +static int __init bcm47xx_wdt_init(void)
 280 +{
 281 +       int ret;
 282 +
 283 +       if (bcm47xx_wdt_hw_stop() < 0)
 284 +               return -ENODEV;
 285 +
 286 +       setup_timer(&wdt_timer, bcm47xx_timer_tick, 0L);
 287 +
 288 +       if (bcm47xx_wdt_settimeout(wdt_time)) {
 289 +               bcm47xx_wdt_settimeout(WDT_DEFAULT_TIME);
 290 +               printk(KERN_INFO DRV_NAME
 291 +                       ": wdt_time value must be 1 <= wdt_time <= 256, using %d\n",
 292 +                       wdt_time);
 293 +       }
 294 +
 295 +       ret = register_reboot_notifier(&bcm47xx_wdt_notifier);
 296 +       if (ret)
 297 +               return ret;
 298 +
 299 +       ret = misc_register(&bcm47xx_wdt_miscdev);
 300 +       if (ret) {
 301 +               unregister_reboot_notifier(&bcm47xx_wdt_notifier);
 302 +               return ret;
 303 +       }
 304 +
 305 +       printk(KERN_INFO "BCM47xx Watchdog Timer enabled (%d seconds%s)\n",
 306 +                               wdt_time, nowayout ? ", nowayout" : "");
 307 +       return 0;
 308 +}
 309 +
 310 +static void __exit bcm47xx_wdt_exit(void)
 311 +{
 312 +       if (!nowayout)
 313 +               bcm47xx_wdt_stop();
 314 +
 315 +       misc_deregister(&bcm47xx_wdt_miscdev);
 316 +
 317 +       unregister_reboot_notifier(&bcm47xx_wdt_notifier);
 318 +}
 319 +
 320 +module_init(bcm47xx_wdt_init);
 321 +module_exit(bcm47xx_wdt_exit);
 322 +
 323 +MODULE_AUTHOR("Aleksandar Radovanovic");
 324 +MODULE_DESCRIPTION("Watchdog driver for Broadcom BCM47xx");
 325 +MODULE_LICENSE("GPL");
 326 +MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);