target/linux/brcm2708/patches-3.18/0005-bcm2708-watchdog-driver.patch

   1 From 633194396e40f919974dd8b81e97ddfea463b733 Mon Sep 17 00:00:00 2001
   2 From: popcornmix <popcornmix@gmail.com>
   3 Date: Wed, 1 May 2013 19:54:32 +0100
   4 Subject: [PATCH 005/114] bcm2708 watchdog driver
   5
   6 Signed-off-by: popcornmix <popcornmix@gmail.com>
   7 ---
   8  drivers/watchdog/Kconfig        |   6 +
   9  drivers/watchdog/Makefile       |   1 +
  10  drivers/watchdog/bcm2708_wdog.c | 382 ++++++++++++++++++++++++++++++++++++++++
  11  3 files changed, 389 insertions(+)
  12  create mode 100644 drivers/watchdog/bcm2708_wdog.c
  13
  14 diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig
  15 index d0107d4..ff56894 100644
  16 --- a/drivers/watchdog/Kconfig
  17 +++ b/drivers/watchdog/Kconfig
  18 @@ -452,6 +452,12 @@ config RETU_WATCHDOG
  19           To compile this driver as a module, choose M here: the
  20           module will be called retu_wdt.
  21
  22 +config BCM2708_WDT
  23 +       tristate "BCM2708 Watchdog"
  24 +       depends on ARCH_BCM2708
  25 +       help
  26 +         Enables BCM2708 watchdog support.
  27 +
  28  config MOXART_WDT
  29         tristate "MOXART watchdog"
  30         depends on ARCH_MOXART
  31 diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile
  32 index c569ec8..10e0665 100644
  33 --- a/drivers/watchdog/Makefile
  34 +++ b/drivers/watchdog/Makefile
  35 @@ -56,6 +56,7 @@ obj-$(CONFIG_TS72XX_WATCHDOG) += ts72xx_wdt.o
  36  obj-$(CONFIG_IMX2_WDT) += imx2_wdt.o
  37  obj-$(CONFIG_UX500_WATCHDOG) += ux500_wdt.o
  38  obj-$(CONFIG_RETU_WATCHDOG) += retu_wdt.o
  39 +obj-$(CONFIG_BCM2708_WDT) += bcm2708_wdog.o
  40  obj-$(CONFIG_BCM2835_WDT) += bcm2835_wdt.o
  41  obj-$(CONFIG_MOXART_WDT) += moxart_wdt.o
  42  obj-$(CONFIG_SIRFSOC_WATCHDOG) += sirfsoc_wdt.o
  43 diff --git a/drivers/watchdog/bcm2708_wdog.c b/drivers/watchdog/bcm2708_wdog.c
  44 new file mode 100644
  45 index 0000000..8a27d68
  46 --- /dev/null
  47 +++ b/drivers/watchdog/bcm2708_wdog.c
  48 @@ -0,0 +1,382 @@
  49 +/*
  50 + *     Broadcom BCM2708 watchdog driver.
  51 + *
  52 + *     (c) Copyright 2010 Broadcom Europe Ltd
  53 + *
  54 + *     This program is free software; you can redistribute it and/or
  55 + *     modify it under the terms of the GNU General Public License
  56 + *     as published by the Free Software Foundation; either version
  57 + *     2 of the License, or (at your option) any later version.
  58 + *
  59 + *      BCM2708 watchdog driver. Loosely based on wdt driver.
  60 + */
  61 +
  62 +#include <linux/interrupt.h>
  63 +#include <linux/module.h>
  64 +#include <linux/moduleparam.h>
  65 +#include <linux/types.h>
  66 +#include <linux/miscdevice.h>
  67 +#include <linux/watchdog.h>
  68 +#include <linux/fs.h>
  69 +#include <linux/ioport.h>
  70 +#include <linux/notifier.h>
  71 +#include <linux/reboot.h>
  72 +#include <linux/init.h>
  73 +#include <linux/io.h>
  74 +#include <linux/uaccess.h>
  75 +#include <mach/platform.h>
  76 +
  77 +#define SECS_TO_WDOG_TICKS(x) ((x) << 16)
  78 +#define WDOG_TICKS_TO_SECS(x) ((x) >> 16)
  79 +
  80 +static unsigned long wdog_is_open;
  81 +static uint32_t wdog_ticks;           /* Ticks to load into wdog timer */
  82 +static char expect_close;
  83 +
  84 +/*
  85 + *     Module parameters
  86 + */
  87 +
  88 +#define WD_TIMO 10                    /* Default heartbeat = 60 seconds */
  89 +static int heartbeat = WD_TIMO;               /* Heartbeat in seconds */
  90 +
  91 +module_param(heartbeat, int, 0);
  92 +MODULE_PARM_DESC(heartbeat,
  93 +       "Watchdog heartbeat in seconds. (0 < heartbeat < 65536, default="
  94 +                               __MODULE_STRING(WD_TIMO) ")");
  95 +
  96 +static int nowayout = WATCHDOG_NOWAYOUT;
  97 +module_param(nowayout, int, 0);
  98 +MODULE_PARM_DESC(nowayout,
  99 +       "Watchdog cannot be stopped once started (default="
 100 +                               __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
 101 +
 102 +static DEFINE_SPINLOCK(wdog_lock);
 103 +
 104 +/**
 105 + *     Start the watchdog driver.
 106 + */
 107 +
 108 +static int wdog_start(unsigned long timeout)
 109 +{
 110 +       uint32_t cur;
 111 +       unsigned long flags;
 112 +       spin_lock_irqsave(&wdog_lock, flags);
 113 +
 114 +       /* enable the watchdog */
 115 +       iowrite32(PM_PASSWORD | (timeout & PM_WDOG_TIME_SET),
 116 +                 __io_address(PM_WDOG));
 117 +       cur = ioread32(__io_address(PM_RSTC));
 118 +       iowrite32(PM_PASSWORD | (cur & PM_RSTC_WRCFG_CLR) |
 119 +                 PM_RSTC_WRCFG_FULL_RESET, __io_address(PM_RSTC));
 120 +
 121 +       spin_unlock_irqrestore(&wdog_lock, flags);
 122 +       return 0;
 123 +}
 124 +
 125 +/**
 126 + *     Stop the watchdog driver.
 127 + */
 128 +
 129 +static int wdog_stop(void)
 130 +{
 131 +       iowrite32(PM_PASSWORD | PM_RSTC_RESET, __io_address(PM_RSTC));
 132 +       printk(KERN_INFO "watchdog stopped\n");
 133 +       return 0;
 134 +}
 135 +
 136 +/**
 137 + *     Reload counter one with the watchdog heartbeat. We don't bother
 138 + *     reloading the cascade counter.
 139 + */
 140 +
 141 +static void wdog_ping(void)
 142 +{
 143 +       wdog_start(wdog_ticks);
 144 +}
 145 +
 146 +/**
 147 + *     @t:             the new heartbeat value that needs to be set.
 148 + *
 149 + *     Set a new heartbeat value for the watchdog device. If the heartbeat
 150 + *     value is incorrect we keep the old value and return -EINVAL. If
 151 + *     successful we return 0.
 152 + */
 153 +
 154 +static int wdog_set_heartbeat(int t)
 155 +{
 156 +       if (t < 1 || t > WDOG_TICKS_TO_SECS(PM_WDOG_TIME_SET))
 157 +               return -EINVAL;
 158 +
 159 +       heartbeat = t;
 160 +       wdog_ticks = SECS_TO_WDOG_TICKS(t);
 161 +       return 0;
 162 +}
 163 +
 164 +/**
 165 + *     @file: file handle to the watchdog
 166 + *     @buf: buffer to write (unused as data does not matter here
 167 + *     @count: count of bytes
 168 + *     @ppos: pointer to the position to write. No seeks allowed
 169 + *
 170 + *     A write to a watchdog device is defined as a keepalive signal.
 171 + *
 172 + *      if 'nowayout' is set then normally a close() is ignored. But
 173 + *      if you write 'V' first then the close() will stop the timer.
 174 + */
 175 +
 176 +static ssize_t wdog_write(struct file *file, const char __user *buf,
 177 +                                               size_t count, loff_t *ppos)
 178 +{
 179 +       if (count) {
 180 +               if (!nowayout) {
 181 +                       size_t i;
 182 +
 183 +                       /* In case it was set long ago */
 184 +                       expect_close = 0;
 185 +
 186 +                       for (i = 0; i != count; i++) {
 187 +                               char c;
 188 +                               if (get_user(c, buf + i))
 189 +                                       return -EFAULT;
 190 +                               if (c == 'V')
 191 +                                       expect_close = 42;
 192 +                       }
 193 +               }
 194 +               wdog_ping();
 195 +       }
 196 +       return count;
 197 +}
 198 +
 199 +static int wdog_get_status(void)
 200 +{
 201 +       unsigned long flags;
 202 +       int status = 0;
 203 +       spin_lock_irqsave(&wdog_lock, flags);
 204 +       /* FIXME: readback reset reason */
 205 +       spin_unlock_irqrestore(&wdog_lock, flags);
 206 +       return status;
 207 +}
 208 +
 209 +static uint32_t wdog_get_remaining(void)
 210 +{
 211 +       uint32_t ret = ioread32(__io_address(PM_WDOG));
 212 +       return ret & PM_WDOG_TIME_SET;
 213 +}
 214 +
 215 +/**
 216 + *     @file: file handle to the device
 217 + *     @cmd: watchdog command
 218 + *     @arg: argument pointer
 219 + *
 220 + *     The watchdog API defines a common set of functions for all watchdogs
 221 + *     according to their available features. We only actually usefully support
 222 + *     querying capabilities and current status.
 223 + */
 224 +
 225 +static long wdog_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 226 +{
 227 +       void __user *argp = (void __user *)arg;
 228 +       int __user *p = argp;
 229 +       int new_heartbeat;
 230 +       int status;
 231 +       int options;
 232 +       uint32_t remaining;
 233 +
 234 +       struct watchdog_info ident = {
 235 +               .options =              WDIOF_SETTIMEOUT|
 236 +                                       WDIOF_MAGICCLOSE|
 237 +                                       WDIOF_KEEPALIVEPING,
 238 +               .firmware_version =     1,
 239 +               .identity =             "BCM2708",
 240 +       };
 241 +
 242 +       switch (cmd) {
 243 +       case WDIOC_GETSUPPORT:
 244 +               return copy_to_user(argp, &ident, sizeof(ident)) ? -EFAULT : 0;
 245 +       case WDIOC_GETSTATUS:
 246 +               status = wdog_get_status();
 247 +               return put_user(status, p);
 248 +       case WDIOC_GETBOOTSTATUS:
 249 +               return put_user(0, p);
 250 +       case WDIOC_KEEPALIVE:
 251 +               wdog_ping();
 252 +               return 0;
 253 +       case WDIOC_SETTIMEOUT:
 254 +               if (get_user(new_heartbeat, p))
 255 +                       return -EFAULT;
 256 +               if (wdog_set_heartbeat(new_heartbeat))
 257 +                       return -EINVAL;
 258 +               wdog_ping();
 259 +               /* Fall */
 260 +       case WDIOC_GETTIMEOUT:
 261 +               return put_user(heartbeat, p);
 262 +       case WDIOC_GETTIMELEFT:
 263 +               remaining = WDOG_TICKS_TO_SECS(wdog_get_remaining());
 264 +               return put_user(remaining, p);
 265 +       case WDIOC_SETOPTIONS:
 266 +               if (get_user(options, p))
 267 +                       return -EFAULT;
 268 +               if (options & WDIOS_DISABLECARD)
 269 +                       wdog_stop();
 270 +               if (options & WDIOS_ENABLECARD)
 271 +                       wdog_start(wdog_ticks);
 272 +               return 0;
 273 +       default:
 274 +               return -ENOTTY;
 275 +       }
 276 +}
 277 +
 278 +/**
 279 + *     @inode: inode of device
 280 + *     @file: file handle to device
 281 + *
 282 + *     The watchdog device has been opened. The watchdog device is single
 283 + *     open and on opening we load the counters.
 284 + */
 285 +
 286 +static int wdog_open(struct inode *inode, struct file *file)
 287 +{
 288 +       if (test_and_set_bit(0, &wdog_is_open))
 289 +               return -EBUSY;
 290 +       /*
 291 +        *      Activate
 292 +        */
 293 +       wdog_start(wdog_ticks);
 294 +       return nonseekable_open(inode, file);
 295 +}
 296 +
 297 +/**
 298 + *     @inode: inode to board
 299 + *     @file: file handle to board
 300 + *
 301 + *     The watchdog has a configurable API. There is a religious dispute
 302 + *     between people who want their watchdog to be able to shut down and
 303 + *     those who want to be sure if the watchdog manager dies the machine
 304 + *     reboots. In the former case we disable the counters, in the latter
 305 + *     case you have to open it again very soon.
 306 + */
 307 +
 308 +static int wdog_release(struct inode *inode, struct file *file)
 309 +{
 310 +       if (expect_close == 42) {
 311 +               wdog_stop();
 312 +       } else {
 313 +               printk(KERN_CRIT
 314 +                "wdt: WDT device closed unexpectedly.  WDT will not stop!\n");
 315 +               wdog_ping();
 316 +       }
 317 +       clear_bit(0, &wdog_is_open);
 318 +       expect_close = 0;
 319 +       return 0;
 320 +}
 321 +
 322 +/**
 323 + *     @this: our notifier block
 324 + *     @code: the event being reported
 325 + *     @unused: unused
 326 + *
 327 + *     Our notifier is called on system shutdowns. Turn the watchdog
 328 + *     off so that it does not fire during the next reboot.
 329 + */
 330 +
 331 +static int wdog_notify_sys(struct notifier_block *this, unsigned long code,
 332 +       void *unused)
 333 +{
 334 +       if (code == SYS_DOWN || code == SYS_HALT)
 335 +               wdog_stop();
 336 +       return NOTIFY_DONE;
 337 +}
 338 +
 339 +/*
 340 + *     Kernel Interfaces
 341 + */
 342 +
 343 +
 344 +static const struct file_operations wdog_fops = {
 345 +       .owner          = THIS_MODULE,
 346 +       .llseek         = no_llseek,
 347 +       .write          = wdog_write,
 348 +       .unlocked_ioctl = wdog_ioctl,
 349 +       .open           = wdog_open,
 350 +       .release        = wdog_release,
 351 +};
 352 +
 353 +static struct miscdevice wdog_miscdev = {
 354 +       .minor  = WATCHDOG_MINOR,
 355 +       .name   = "watchdog",
 356 +       .fops   = &wdog_fops,
 357 +};
 358 +
 359 +/*
 360 + *     The WDT card needs to learn about soft shutdowns in order to
 361 + *     turn the timebomb registers off.
 362 + */
 363 +
 364 +static struct notifier_block wdog_notifier = {
 365 +       .notifier_call = wdog_notify_sys,
 366 +};
 367 +
 368 +/**
 369 + *     cleanup_module:
 370 + *
 371 + *     Unload the watchdog. You cannot do this with any file handles open.
 372 + *     If your watchdog is set to continue ticking on close and you unload
 373 + *     it, well it keeps ticking. We won't get the interrupt but the board
 374 + *     will not touch PC memory so all is fine. You just have to load a new
 375 + *     module in 60 seconds or reboot.
 376 + */
 377 +
 378 +static void __exit wdog_exit(void)
 379 +{
 380 +       misc_deregister(&wdog_miscdev);
 381 +       unregister_reboot_notifier(&wdog_notifier);
 382 +}
 383 +
 384 +static int __init wdog_init(void)
 385 +{
 386 +       int ret;
 387 +
 388 +       /* Check that the heartbeat value is within it's range;
 389 +          if not reset to the default */
 390 +       if (wdog_set_heartbeat(heartbeat)) {
 391 +               wdog_set_heartbeat(WD_TIMO);
 392 +               printk(KERN_INFO "bcm2708_wdog: heartbeat value must be "
 393 +                       "0 < heartbeat < %d, using %d\n",
 394 +                               WDOG_TICKS_TO_SECS(PM_WDOG_TIME_SET),
 395 +                               WD_TIMO);
 396 +       }
 397 +
 398 +       ret = register_reboot_notifier(&wdog_notifier);
 399 +       if (ret) {
 400 +               printk(KERN_ERR
 401 +                     "wdt: cannot register reboot notifier (err=%d)\n", ret);
 402 +               goto out_reboot;
 403 +       }
 404 +
 405 +       ret = misc_register(&wdog_miscdev);
 406 +       if (ret) {
 407 +               printk(KERN_ERR
 408 +                       "wdt: cannot register miscdev on minor=%d (err=%d)\n",
 409 +                                                       WATCHDOG_MINOR, ret);
 410 +               goto out_misc;
 411 +       }
 412 +
 413 +       printk(KERN_INFO "bcm2708 watchdog, heartbeat=%d sec (nowayout=%d)\n",
 414 +               heartbeat, nowayout);
 415 +       return 0;
 416 +
 417 +out_misc:
 418 +       unregister_reboot_notifier(&wdog_notifier);
 419 +out_reboot:
 420 +       return ret;
 421 +}
 422 +
 423 +module_init(wdog_init);
 424 +module_exit(wdog_exit);
 425 +
 426 +MODULE_AUTHOR("Luke Diamand");
 427 +MODULE_DESCRIPTION("Driver for BCM2708 watchdog");
 428 +MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
 429 +MODULE_ALIAS_MISCDEV(TEMP_MINOR);
 430 +MODULE_LICENSE("GPL");
 431 --
 432 1.8.3.2
 433