target/linux/brcm2708/patches-3.10/003-bcm2708-watchdog-driver.patch

   1 diff -urN linux-3.10/drivers/watchdog/bcm2708_wdog.c linux-rpi-3.10.y/drivers/watchdog/bcm2708_wdog.c
   2 --- linux-3.10/drivers/watchdog/bcm2708_wdog.c  1970-01-01 01:00:00.000000000 +0100
   3 +++ linux-rpi-3.10.y/drivers/watchdog/bcm2708_wdog.c    2013-07-06 15:25:50.000000000 +0100
   4 @@ -0,0 +1,385 @@
   5 +/*
   6 + *     Broadcom BCM2708 watchdog driver.
   7 + *
   8 + *     (c) Copyright 2010 Broadcom Europe Ltd
   9 + *
  10 + *     This program is free software; you can redistribute it and/or
  11 + *     modify it under the terms of the GNU General Public License
  12 + *     as published by the Free Software Foundation; either version
  13 + *     2 of the License, or (at your option) any later version.
  14 + *
  15 + *      BCM2708 watchdog driver. Loosely based on wdt driver.
  16 + */
  17 +
  18 +#include <linux/interrupt.h>
  19 +#include <linux/module.h>
  20 +#include <linux/moduleparam.h>
  21 +#include <linux/types.h>
  22 +#include <linux/miscdevice.h>
  23 +#include <linux/watchdog.h>
  24 +#include <linux/fs.h>
  25 +#include <linux/ioport.h>
  26 +#include <linux/notifier.h>
  27 +#include <linux/reboot.h>
  28 +#include <linux/init.h>
  29 +#include <linux/io.h>
  30 +#include <linux/uaccess.h>
  31 +#include <mach/platform.h>
  32 +
  33 +#include <asm/system.h>
  34 +
  35 +#define SECS_TO_WDOG_TICKS(x) ((x) << 16)
  36 +#define WDOG_TICKS_TO_SECS(x) ((x) >> 16)
  37 +
  38 +static unsigned long wdog_is_open;
  39 +static uint32_t wdog_ticks;           /* Ticks to load into wdog timer */
  40 +static char expect_close;
  41 +
  42 +/*
  43 + *     Module parameters
  44 + */
  45 +
  46 +#define WD_TIMO 10                    /* Default heartbeat = 60 seconds */
  47 +static int heartbeat = WD_TIMO;               /* Heartbeat in seconds */
  48 +
  49 +module_param(heartbeat, int, 0);
  50 +MODULE_PARM_DESC(heartbeat,
  51 +       "Watchdog heartbeat in seconds. (0 < heartbeat < 65536, default="
  52 +                               __MODULE_STRING(WD_TIMO) ")");
  53 +
  54 +static int nowayout = WATCHDOG_NOWAYOUT;
  55 +module_param(nowayout, int, 0);
  56 +MODULE_PARM_DESC(nowayout,
  57 +       "Watchdog cannot be stopped once started (default="
  58 +                               __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
  59 +
  60 +static DEFINE_SPINLOCK(wdog_lock);
  61 +
  62 +/**
  63 + *     Start the watchdog driver.
  64 + */
  65 +
  66 +static int wdog_start(unsigned long timeout)
  67 +{
  68 +       uint32_t cur;
  69 +       unsigned long flags;
  70 +       spin_lock_irqsave(&wdog_lock, flags);
  71 +
  72 +       /* enable the watchdog */
  73 +       iowrite32(PM_PASSWORD | (timeout & PM_WDOG_TIME_SET),
  74 +                 __io_address(PM_WDOG));
  75 +       cur = ioread32(__io_address(PM_RSTC));
  76 +       iowrite32(PM_PASSWORD | (cur & PM_RSTC_WRCFG_CLR) |
  77 +                 PM_RSTC_WRCFG_FULL_RESET, __io_address(PM_RSTC));
  78 +
  79 +       spin_unlock_irqrestore(&wdog_lock, flags);
  80 +       return 0;
  81 +}
  82 +
  83 +/**
  84 + *     Stop the watchdog driver.
  85 + */
  86 +
  87 +static int wdog_stop(void)
  88 +{
  89 +       iowrite32(PM_PASSWORD | PM_RSTC_RESET, __io_address(PM_RSTC));
  90 +       printk(KERN_INFO "watchdog stopped\n");
  91 +       return 0;
  92 +}
  93 +
  94 +/**
  95 + *     Reload counter one with the watchdog heartbeat. We don't bother
  96 + *     reloading the cascade counter.
  97 + */
  98 +
  99 +static void wdog_ping(void)
 100 +{
 101 +       wdog_start(wdog_ticks);
 102 +}
 103 +
 104 +/**
 105 + *     @t:             the new heartbeat value that needs to be set.
 106 + *
 107 + *     Set a new heartbeat value for the watchdog device. If the heartbeat
 108 + *     value is incorrect we keep the old value and return -EINVAL. If
 109 + *     successful we return 0.
 110 + */
 111 +
 112 +static int wdog_set_heartbeat(int t)
 113 +{
 114 +       if (t < 1 || t > WDOG_TICKS_TO_SECS(PM_WDOG_TIME_SET))
 115 +               return -EINVAL;
 116 +
 117 +       heartbeat = t;
 118 +       wdog_ticks = SECS_TO_WDOG_TICKS(t);
 119 +       return 0;
 120 +}
 121 +
 122 +/**
 123 + *     @file: file handle to the watchdog
 124 + *     @buf: buffer to write (unused as data does not matter here
 125 + *     @count: count of bytes
 126 + *     @ppos: pointer to the position to write. No seeks allowed
 127 + *
 128 + *     A write to a watchdog device is defined as a keepalive signal.
 129 + *
 130 + *      if 'nowayout' is set then normally a close() is ignored. But
 131 + *      if you write 'V' first then the close() will stop the timer.
 132 + */
 133 +
 134 +static ssize_t wdog_write(struct file *file, const char __user *buf,
 135 +                                               size_t count, loff_t *ppos)
 136 +{
 137 +       if (count) {
 138 +               if (!nowayout) {
 139 +                       size_t i;
 140 +
 141 +                       /* In case it was set long ago */
 142 +                       expect_close = 0;
 143 +
 144 +                       for (i = 0; i != count; i++) {
 145 +                               char c;
 146 +                               if (get_user(c, buf + i))
 147 +                                       return -EFAULT;
 148 +                               if (c == 'V')
 149 +                                       expect_close = 42;
 150 +                       }
 151 +               }
 152 +               wdog_ping();
 153 +       }
 154 +       return count;
 155 +}
 156 +
 157 +static int wdog_get_status(void)
 158 +{
 159 +       unsigned long flags;
 160 +       int status = 0;
 161 +       spin_lock_irqsave(&wdog_lock, flags);
 162 +       /* FIXME: readback reset reason */
 163 +       spin_unlock_irqrestore(&wdog_lock, flags);
 164 +       return status;
 165 +}
 166 +
 167 +static uint32_t wdog_get_remaining(void)
 168 +{
 169 +       uint32_t ret = ioread32(__io_address(PM_WDOG));
 170 +       return ret & PM_WDOG_TIME_SET;
 171 +}
 172 +
 173 +/**
 174 + *     @file: file handle to the device
 175 + *     @cmd: watchdog command
 176 + *     @arg: argument pointer
 177 + *
 178 + *     The watchdog API defines a common set of functions for all watchdogs
 179 + *     according to their available features. We only actually usefully support
 180 + *     querying capabilities and current status.
 181 + */
 182 +
 183 +static long wdog_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 184 +{
 185 +       void __user *argp = (void __user *)arg;
 186 +       int __user *p = argp;
 187 +       int new_heartbeat;
 188 +       int status;
 189 +       int options;
 190 +       uint32_t remaining;
 191 +
 192 +       struct watchdog_info ident = {
 193 +               .options =              WDIOF_SETTIMEOUT|
 194 +                                       WDIOF_MAGICCLOSE|
 195 +                                       WDIOF_KEEPALIVEPING,
 196 +               .firmware_version =     1,
 197 +               .identity =             "BCM2708",
 198 +       };
 199 +
 200 +       switch (cmd) {
 201 +       case WDIOC_GETSUPPORT:
 202 +               return copy_to_user(argp, &ident, sizeof(ident)) ? -EFAULT : 0;
 203 +       case WDIOC_GETSTATUS:
 204 +               status = wdog_get_status();
 205 +               return put_user(status, p);
 206 +       case WDIOC_GETBOOTSTATUS:
 207 +               return put_user(0, p);
 208 +       case WDIOC_KEEPALIVE:
 209 +               wdog_ping();
 210 +               return 0;
 211 +       case WDIOC_SETTIMEOUT:
 212 +               if (get_user(new_heartbeat, p))
 213 +                       return -EFAULT;
 214 +               if (wdog_set_heartbeat(new_heartbeat))
 215 +                       return -EINVAL;
 216 +               wdog_ping();
 217 +               /* Fall */
 218 +       case WDIOC_GETTIMEOUT:
 219 +               return put_user(heartbeat, p);
 220 +       case WDIOC_GETTIMELEFT:
 221 +               remaining = WDOG_TICKS_TO_SECS(wdog_get_remaining());
 222 +               return put_user(remaining, p);
 223 +       case WDIOC_SETOPTIONS:
 224 +               if (get_user(options, p))
 225 +                       return -EFAULT;
 226 +               if (options & WDIOS_DISABLECARD)
 227 +                       wdog_stop();
 228 +               if (options & WDIOS_ENABLECARD)
 229 +                       wdog_start(wdog_ticks);
 230 +               return 0;
 231 +       default:
 232 +               return -ENOTTY;
 233 +       }
 234 +}
 235 +
 236 +/**
 237 + *     @inode: inode of device
 238 + *     @file: file handle to device
 239 + *
 240 + *     The watchdog device has been opened. The watchdog device is single
 241 + *     open and on opening we load the counters.
 242 + */
 243 +
 244 +static int wdog_open(struct inode *inode, struct file *file)
 245 +{
 246 +       if (test_and_set_bit(0, &wdog_is_open))
 247 +               return -EBUSY;
 248 +       /*
 249 +        *      Activate
 250 +        */
 251 +       wdog_start(wdog_ticks);
 252 +       return nonseekable_open(inode, file);
 253 +}
 254 +
 255 +/**
 256 + *     @inode: inode to board
 257 + *     @file: file handle to board
 258 + *
 259 + *     The watchdog has a configurable API. There is a religious dispute
 260 + *     between people who want their watchdog to be able to shut down and
 261 + *     those who want to be sure if the watchdog manager dies the machine
 262 + *     reboots. In the former case we disable the counters, in the latter
 263 + *     case you have to open it again very soon.
 264 + */
 265 +
 266 +static int wdog_release(struct inode *inode, struct file *file)
 267 +{
 268 +       if (expect_close == 42) {
 269 +               wdog_stop();
 270 +       } else {
 271 +               printk(KERN_CRIT
 272 +                "wdt: WDT device closed unexpectedly.  WDT will not stop!\n");
 273 +               wdog_ping();
 274 +       }
 275 +       clear_bit(0, &wdog_is_open);
 276 +       expect_close = 0;
 277 +       return 0;
 278 +}
 279 +
 280 +/**
 281 + *     @this: our notifier block
 282 + *     @code: the event being reported
 283 + *     @unused: unused
 284 + *
 285 + *     Our notifier is called on system shutdowns. Turn the watchdog
 286 + *     off so that it does not fire during the next reboot.
 287 + */
 288 +
 289 +static int wdog_notify_sys(struct notifier_block *this, unsigned long code,
 290 +       void *unused)
 291 +{
 292 +       if (code == SYS_DOWN || code == SYS_HALT)
 293 +               wdog_stop();
 294 +       return NOTIFY_DONE;
 295 +}
 296 +
 297 +/*
 298 + *     Kernel Interfaces
 299 + */
 300 +
 301 +
 302 +static const struct file_operations wdog_fops = {
 303 +       .owner          = THIS_MODULE,
 304 +       .llseek         = no_llseek,
 305 +       .write          = wdog_write,
 306 +       .unlocked_ioctl = wdog_ioctl,
 307 +       .open           = wdog_open,
 308 +       .release        = wdog_release,
 309 +};
 310 +
 311 +static struct miscdevice wdog_miscdev = {
 312 +       .minor  = WATCHDOG_MINOR,
 313 +       .name   = "watchdog",
 314 +       .fops   = &wdog_fops,
 315 +};
 316 +
 317 +/*
 318 + *     The WDT card needs to learn about soft shutdowns in order to
 319 + *     turn the timebomb registers off.
 320 + */
 321 +
 322 +static struct notifier_block wdog_notifier = {
 323 +       .notifier_call = wdog_notify_sys,
 324 +};
 325 +
 326 +/**
 327 + *     cleanup_module:
 328 + *
 329 + *     Unload the watchdog. You cannot do this with any file handles open.
 330 + *     If your watchdog is set to continue ticking on close and you unload
 331 + *     it, well it keeps ticking. We won't get the interrupt but the board
 332 + *     will not touch PC memory so all is fine. You just have to load a new
 333 + *     module in 60 seconds or reboot.
 334 + */
 335 +
 336 +static void __exit wdog_exit(void)
 337 +{
 338 +       misc_deregister(&wdog_miscdev);
 339 +       unregister_reboot_notifier(&wdog_notifier);
 340 +}
 341 +
 342 +static int __init wdog_init(void)
 343 +{
 344 +       int ret;
 345 +
 346 +       /* Check that the heartbeat value is within it's range;
 347 +          if not reset to the default */
 348 +       if (wdog_set_heartbeat(heartbeat)) {
 349 +               wdog_set_heartbeat(WD_TIMO);
 350 +               printk(KERN_INFO "bcm2708_wdog: heartbeat value must be "
 351 +                       "0 < heartbeat < %d, using %d\n",
 352 +                               WDOG_TICKS_TO_SECS(PM_WDOG_TIME_SET),
 353 +                               WD_TIMO);
 354 +       }
 355 +
 356 +       ret = register_reboot_notifier(&wdog_notifier);
 357 +       if (ret) {
 358 +               printk(KERN_ERR
 359 +                     "wdt: cannot register reboot notifier (err=%d)\n", ret);
 360 +               goto out_reboot;
 361 +       }
 362 +
 363 +       ret = misc_register(&wdog_miscdev);
 364 +       if (ret) {
 365 +               printk(KERN_ERR
 366 +                       "wdt: cannot register miscdev on minor=%d (err=%d)\n",
 367 +                                                       WATCHDOG_MINOR, ret);
 368 +               goto out_misc;
 369 +       }
 370 +
 371 +       printk(KERN_INFO "bcm2708 watchdog, heartbeat=%d sec (nowayout=%d)\n",
 372 +               heartbeat, nowayout);
 373 +       return 0;
 374 +
 375 +out_misc:
 376 +       unregister_reboot_notifier(&wdog_notifier);
 377 +out_reboot:
 378 +       return ret;
 379 +}
 380 +
 381 +module_init(wdog_init);
 382 +module_exit(wdog_exit);
 383 +
 384 +MODULE_AUTHOR("Luke Diamand");
 385 +MODULE_DESCRIPTION("Driver for BCM2708 watchdog");
 386 +MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
 387 +MODULE_ALIAS_MISCDEV(TEMP_MINOR);
 388 +MODULE_LICENSE("GPL");
 389 +
 390 diff -urN linux-3.10/drivers/watchdog/Kconfig linux-rpi-3.10.y/drivers/watchdog/Kconfig
 391 --- linux-3.10/drivers/watchdog/Kconfig 2013-06-30 23:13:29.000000000 +0100
 392 +++ linux-rpi-3.10.y/drivers/watchdog/Kconfig   2013-07-06 15:25:50.000000000 +0100
 393 @@ -391,6 +391,12 @@
 394           To compile this driver as a module, choose M here: the
 395           module will be called retu_wdt.
 396
 397 +config BCM2708_WDT
 398 +       tristate "BCM2708 Watchdog"
 399 +       depends on ARCH_BCM2708
 400 +       help
 401 +         Enables BCM2708 watchdog support.
 402 +
 403  # AVR32 Architecture
 404
 405  config AT32AP700X_WDT
 406 diff -urN linux-3.10/drivers/watchdog/Makefile linux-rpi-3.10.y/drivers/watchdog/Makefile
 407 --- linux-3.10/drivers/watchdog/Makefile        2013-06-30 23:13:29.000000000 +0100
 408 +++ linux-rpi-3.10.y/drivers/watchdog/Makefile  2013-07-06 15:25:50.000000000 +0100
 409 @@ -54,6 +54,7 @@
 410  obj-$(CONFIG_IMX2_WDT) += imx2_wdt.o
 411  obj-$(CONFIG_UX500_WATCHDOG) += ux500_wdt.o
 412  obj-$(CONFIG_RETU_WATCHDOG) += retu_wdt.o
 413 +obj-$(CONFIG_BCM2708_WDT) += bcm2708_wdog.o
 414
 415  # AVR32 Architecture
 416  obj-$(CONFIG_AT32AP700X_WDT) += at32ap700x_wdt.o