target/linux/cns3xxx/patches-2.6.31/209-cns3xxx_watchdog_support.patch

   1 --- /dev/null
   2 +++ b/drivers/watchdog/cns3xxx_wdt.c
   3 @@ -0,0 +1,465 @@
   4 +/*******************************************************************************
   5 + *
   6 + *  drivers/watchdog/cns3xxx_wdt.c
   7 + *
   8 + *  Watchdog timer driver for the CNS3XXX SOCs
   9 + *
  10 + *  Author: Scott Shu
  11 + *
  12 + *  Copyright (c) 2008 Cavium Networks
  13 + *
  14 + *  This file is free software; you can redistribute it and/or modify
  15 + *  it under the terms of the GNU General Public License, Version 2, as
  16 + *  published by the Free Software Foundation.
  17 + *
  18 + *  This file is distributed in the hope that it will be useful,
  19 + *  but AS-IS and WITHOUT ANY WARRANTY; without even the implied warranty of
  20 + *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE, TITLE, or
  21 + *  NONINFRINGEMENT.  See the GNU General Public License for more details.
  22 + *
  23 + *  You should have received a copy of the GNU General Public License
  24 + *  along with this file; if not, write to the Free Software
  25 + *  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA or
  26 + *  visit http://www.gnu.org/licenses/.
  27 + *
  28 + *  This file may also be available under a different license from Cavium.
  29 + *  Contact Cavium Networks for more information
  30 + *
  31 + ******************************************************************************/
  32 +
  33 +#include <linux/module.h>
  34 +#include <linux/moduleparam.h>
  35 +#include <linux/types.h>
  36 +#include <linux/miscdevice.h>
  37 +#include <linux/watchdog.h>
  38 +#include <linux/fs.h>
  39 +#include <linux/reboot.h>
  40 +#include <linux/init.h>
  41 +#include <linux/interrupt.h>
  42 +#include <linux/platform_device.h>
  43 +#include <linux/io.h>
  44 +#include <linux/uaccess.h>
  45 +
  46 +#include <asm/hardware/arm_twd.h>
  47 +
  48 +struct cns3xxx_wdt {
  49 +       unsigned long   timer_alive;
  50 +       struct device   *dev;
  51 +       void __iomem    *base;
  52 +       int             irq;
  53 +       unsigned int    perturb;
  54 +       char            expect_close;
  55 +};
  56 +
  57 +static struct platform_device *cns3xxx_wdt_dev;
  58 +extern unsigned int twd_timer_rate;
  59 +static spinlock_t wdt_lock;
  60 +
  61 +#define TIMER_MARGIN   60
  62 +static int cns3xxx_margin = TIMER_MARGIN;
  63 +module_param(cns3xxx_margin, int, 0);
  64 +MODULE_PARM_DESC(cns3xxx_margin,
  65 +       "CNS3XXX timer margin in seconds. (0 < cns3xxx_margin < 65536, default="
  66 +                               __MODULE_STRING(TIMER_MARGIN) ")");
  67 +
  68 +static int nowayout = WATCHDOG_NOWAYOUT;
  69 +module_param(nowayout, int, 0);
  70 +MODULE_PARM_DESC(nowayout,
  71 +       "Watchdog cannot be stopped once started (default="
  72 +                               __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
  73 +
  74 +#define ONLY_TESTING   0
  75 +static int cns3xxx_noboot = ONLY_TESTING;
  76 +module_param(cns3xxx_noboot, int, 0);
  77 +MODULE_PARM_DESC(cns3xxx_noboot, "CNS3XXX watchdog action, "
  78 +       "set to 1 to ignore reboots, 0 to reboot (default="
  79 +                                       __MODULE_STRING(ONLY_TESTING) ")");
  80 +
  81 +/*
  82 + *     This is the interrupt handler.  Note that we only use this
  83 + *     in testing mode, so don't actually do a reboot here.
  84 + */
  85 +static irqreturn_t cns3xxx_wdt_fire(int irq, void *arg)
  86 +{
  87 +       struct cns3xxx_wdt *wdt = arg;
  88 +
  89 +       /* Check it really was our interrupt */
  90 +       if (readl(wdt->base + TWD_WDOG_INTSTAT)) {
  91 +               dev_printk(KERN_CRIT, wdt->dev,
  92 +                                       "Triggered - Reboot ignored.\n");
  93 +               /* Clear the interrupt on the watchdog */
  94 +               writel(1, wdt->base + TWD_WDOG_INTSTAT);
  95 +               return IRQ_HANDLED;
  96 +       }
  97 +       return IRQ_NONE;
  98 +}
  99 +
 100 +/*
 101 + *     cns3xxx_wdt_keepalive - reload the timer
 102 + *
 103 + *     Note that the spec says a DIFFERENT value must be written to the reload
 104 + *     register each time.  The "perturb" variable deals with this by adding 1
 105 + *     to the count every other time the function is called.
 106 + */
 107 +static void cns3xxx_wdt_keepalive(struct cns3xxx_wdt *wdt)
 108 +{
 109 +       unsigned int count;
 110 +
 111 +       /* Assume prescale is set to 256 */
 112 +       count = (twd_timer_rate / 256) * cns3xxx_margin;
 113 +
 114 +       /* Reload the counter */
 115 +       spin_lock(&wdt_lock);
 116 +       writel(count + wdt->perturb, wdt->base + TWD_WDOG_LOAD);
 117 +       wdt->perturb = wdt->perturb ? 0 : 1;
 118 +       spin_unlock(&wdt_lock);
 119 +}
 120 +
 121 +static void cns3xxx_wdt_stop(struct cns3xxx_wdt *wdt)
 122 +{
 123 +       spin_lock(&wdt_lock);
 124 +       writel(0x12345678, wdt->base + TWD_WDOG_DISABLE);
 125 +       writel(0x87654321, wdt->base + TWD_WDOG_DISABLE);
 126 +       writel(0x0, wdt->base + TWD_WDOG_CONTROL);
 127 +       spin_unlock(&wdt_lock);
 128 +}
 129 +
 130 +static void cns3xxx_wdt_start(struct cns3xxx_wdt *wdt)
 131 +{
 132 +       dev_printk(KERN_INFO, wdt->dev, "enabling watchdog.\n");
 133 +
 134 +       //spin_lock(&wdt_lock);
 135 +       /* This loads the count register but does NOT start the count yet */
 136 +       cns3xxx_wdt_keepalive(wdt);
 137 +       spin_lock(&wdt_lock);
 138 +
 139 +       if (cns3xxx_noboot) {
 140 +               /* Enable watchdog - prescale=256, watchdog mode=0, enable=1 */
 141 +               writel(0x0000FF01, wdt->base + TWD_WDOG_CONTROL);
 142 +       } else {
 143 +               /* Enable watchdog - prescale=256, watchdog mode=1, enable=1 */
 144 +               writel(0x0000FF09, wdt->base + TWD_WDOG_CONTROL);
 145 +       }
 146 +       spin_unlock(&wdt_lock);
 147 +}
 148 +
 149 +static int cns3xxx_wdt_set_heartbeat(int t)
 150 +{
 151 +       if (t < 0x0001 || t > 0xFFFF)
 152 +               return -EINVAL;
 153 +
 154 +       cns3xxx_margin = t;
 155 +       return 0;
 156 +}
 157 +
 158 +/*
 159 + *     /dev/watchdog handling
 160 + */
 161 +static int cns3xxx_wdt_open(struct inode *inode, struct file *file)
 162 +{
 163 +       struct cns3xxx_wdt *wdt = platform_get_drvdata(cns3xxx_wdt_dev);
 164 +
 165 +       if (test_and_set_bit(0, &wdt->timer_alive))
 166 +               return -EBUSY;
 167 +
 168 +       if (nowayout)
 169 +               __module_get(THIS_MODULE);
 170 +
 171 +       file->private_data = wdt;
 172 +
 173 +       /*
 174 +        *      Activate timer
 175 +        */
 176 +       cns3xxx_wdt_start(wdt);
 177 +
 178 +       return nonseekable_open(inode, file);
 179 +}
 180 +
 181 +static int cns3xxx_wdt_release(struct inode *inode, struct file *file)
 182 +{
 183 +       struct cns3xxx_wdt *wdt = file->private_data;
 184 +
 185 +       /*
 186 +        *      Shut off the timer.
 187 +        *      Lock it in if it's a module and we set nowayout
 188 +        */
 189 +       if (wdt->expect_close == 42)
 190 +               cns3xxx_wdt_stop(wdt);
 191 +       else {
 192 +               dev_printk(KERN_CRIT, wdt->dev,
 193 +                               "unexpected close, not stopping watchdog!\n");
 194 +               cns3xxx_wdt_keepalive(wdt);
 195 +       }
 196 +       clear_bit(0, &wdt->timer_alive);
 197 +       wdt->expect_close = 0;
 198 +       return 0;
 199 +}
 200 +
 201 +static ssize_t cns3xxx_wdt_write(struct file *file, const char *data,
 202 +                                               size_t len, loff_t *ppos)
 203 +{
 204 +       struct cns3xxx_wdt *wdt = file->private_data;
 205 +
 206 +       /*
 207 +        *      Refresh the timer.
 208 +        */
 209 +       if (len) {
 210 +               if (!nowayout) {
 211 +                       size_t i;
 212 +
 213 +                       /* In case it was set long ago */
 214 +                       wdt->expect_close = 0;
 215 +
 216 +                       for (i = 0; i != len; i++) {
 217 +                               char c;
 218 +
 219 +                               if (get_user(c, data + i))
 220 +                                       return -EFAULT;
 221 +                               if (c == 'V')
 222 +                                       wdt->expect_close = 42;
 223 +                       }
 224 +               }
 225 +               cns3xxx_wdt_keepalive(wdt);
 226 +       }
 227 +       return len;
 228 +}
 229 +
 230 +static struct watchdog_info ident = {
 231 +       .options                = WDIOF_SETTIMEOUT |
 232 +                                 WDIOF_KEEPALIVEPING |
 233 +                                 WDIOF_MAGICCLOSE,
 234 +       .identity               = "CNS3XXX Watchdog",
 235 +};
 236 +
 237 +static long cns3xxx_wdt_ioctl(struct file *file, unsigned int cmd,
 238 +                                                       unsigned long arg)
 239 +{
 240 +       struct cns3xxx_wdt *wdt = file->private_data;
 241 +       int ret;
 242 +       union {
 243 +               struct watchdog_info ident;
 244 +               int i;
 245 +       } uarg;
 246 +
 247 +       if (_IOC_DIR(cmd) && _IOC_SIZE(cmd) > sizeof(uarg))
 248 +               return -ENOTTY;
 249 +
 250 +       if (_IOC_DIR(cmd) & _IOC_WRITE) {
 251 +               ret = copy_from_user(&uarg, (void __user *)arg, _IOC_SIZE(cmd));
 252 +               if (ret)
 253 +                       return -EFAULT;
 254 +       }
 255 +
 256 +       switch (cmd) {
 257 +       case WDIOC_GETSUPPORT:
 258 +               uarg.ident = ident;
 259 +               ret = 0;
 260 +               break;
 261 +
 262 +       case WDIOC_GETSTATUS:
 263 +       case WDIOC_GETBOOTSTATUS:
 264 +               uarg.i = 0;
 265 +               ret = 0;
 266 +               break;
 267 +
 268 +       case WDIOC_SETOPTIONS:
 269 +               ret = -EINVAL;
 270 +               if (uarg.i & WDIOS_DISABLECARD) {
 271 +                       cns3xxx_wdt_stop(wdt);
 272 +                       ret = 0;
 273 +               }
 274 +               if (uarg.i & WDIOS_ENABLECARD) {
 275 +                       cns3xxx_wdt_start(wdt);
 276 +                       ret = 0;
 277 +               }
 278 +               break;
 279 +
 280 +       case WDIOC_KEEPALIVE:
 281 +               cns3xxx_wdt_keepalive(wdt);
 282 +               ret = 0;
 283 +               break;
 284 +
 285 +       case WDIOC_SETTIMEOUT:
 286 +               ret = cns3xxx_wdt_set_heartbeat(uarg.i);
 287 +               if (ret)
 288 +                       break;
 289 +
 290 +               cns3xxx_wdt_keepalive(wdt);
 291 +               /* Fall */
 292 +       case WDIOC_GETTIMEOUT:
 293 +               uarg.i = cns3xxx_margin;
 294 +               ret = 0;
 295 +               break;
 296 +
 297 +       default:
 298 +               return -ENOTTY;
 299 +       }
 300 +
 301 +       if (ret == 0 && _IOC_DIR(cmd) & _IOC_READ) {
 302 +               ret = copy_to_user((void __user *)arg, &uarg, _IOC_SIZE(cmd));
 303 +               if (ret)
 304 +                       ret = -EFAULT;
 305 +       }
 306 +       return ret;
 307 +}
 308 +
 309 +/*
 310 + *     System shutdown handler.  Turn off the watchdog if we're
 311 + *     restarting or halting the system.
 312 + */
 313 +static void cns3xxx_wdt_shutdown(struct platform_device *dev)
 314 +{
 315 +       struct cns3xxx_wdt *wdt = platform_get_drvdata(dev);
 316 +
 317 +       if (system_state == SYSTEM_RESTART || system_state == SYSTEM_HALT)
 318 +               cns3xxx_wdt_stop(wdt);
 319 +}
 320 +
 321 +/*
 322 + *     Kernel Interfaces
 323 + */
 324 +static const struct file_operations cns3xxx_wdt_fops = {
 325 +       .owner          = THIS_MODULE,
 326 +       .llseek         = no_llseek,
 327 +       .write          = cns3xxx_wdt_write,
 328 +       .unlocked_ioctl = cns3xxx_wdt_ioctl,
 329 +       .open           = cns3xxx_wdt_open,
 330 +       .release        = cns3xxx_wdt_release,
 331 +};
 332 +
 333 +static struct miscdevice cns3xxx_wdt_miscdev = {
 334 +       .minor          = WATCHDOG_MINOR,
 335 +       .name           = "watchdog",
 336 +       .fops           = &cns3xxx_wdt_fops,
 337 +};
 338 +
 339 +static int __devinit cns3xxx_wdt_probe(struct platform_device *dev)
 340 +{
 341 +       struct cns3xxx_wdt *wdt;
 342 +       struct resource *res;
 343 +       int ret;
 344 +
 345 +       /* We only accept one device, and it must have an id of -1 */
 346 +       if (dev->id != -1)
 347 +               return -ENODEV;
 348 +
 349 +       res = platform_get_resource(dev, IORESOURCE_MEM, 0);
 350 +       if (!res) {
 351 +               ret = -ENODEV;
 352 +               goto err_out;
 353 +       }
 354 +
 355 +       wdt = kzalloc(sizeof(struct cns3xxx_wdt), GFP_KERNEL);
 356 +       if (!wdt) {
 357 +               ret = -ENOMEM;
 358 +               goto err_out;
 359 +       }
 360 +
 361 +       wdt->dev = &dev->dev;
 362 +       wdt->irq = platform_get_irq(dev, 0);
 363 +       if (wdt->irq < 0) {
 364 +               ret = -ENXIO;
 365 +               goto err_free;
 366 +       }
 367 +       wdt->base = ioremap(res->start, res->end - res->start + 1);
 368 +       if (!wdt->base) {
 369 +               ret = -ENOMEM;
 370 +               goto err_free;
 371 +       }
 372 +
 373 +       cns3xxx_wdt_miscdev.parent = &dev->dev;
 374 +       ret = misc_register(&cns3xxx_wdt_miscdev);
 375 +       if (ret) {
 376 +               dev_printk(KERN_ERR, wdt->dev,
 377 +                       "cannot register miscdev on minor=%d (err=%d)\n",
 378 +                                                       WATCHDOG_MINOR, ret);
 379 +               goto err_misc;
 380 +       }
 381 +
 382 +       ret = request_irq(wdt->irq, cns3xxx_wdt_fire, IRQF_DISABLED,
 383 +                       dev->name, wdt);
 384 +       if (ret) {
 385 +               dev_printk(KERN_ERR, wdt->dev,
 386 +                       "cannot register IRQ%d for watchdog\n", wdt->irq);
 387 +               goto err_irq;
 388 +       }
 389 +
 390 +       cns3xxx_wdt_stop(wdt);
 391 +       platform_set_drvdata(dev, wdt);
 392 +       cns3xxx_wdt_dev = dev;
 393 +
 394 +       return 0;
 395 +
 396 +err_irq:
 397 +       misc_deregister(&cns3xxx_wdt_miscdev);
 398 +err_misc:
 399 +       platform_set_drvdata(dev, NULL);
 400 +       iounmap(wdt->base);
 401 +err_free:
 402 +       kfree(wdt);
 403 +err_out:
 404 +       return ret;
 405 +}
 406 +
 407 +static int __devexit cns3xxx_wdt_remove(struct platform_device *dev)
 408 +{
 409 +       struct cns3xxx_wdt *wdt = platform_get_drvdata(dev);
 410 +
 411 +       platform_set_drvdata(dev, NULL);
 412 +
 413 +       misc_deregister(&cns3xxx_wdt_miscdev);
 414 +
 415 +       cns3xxx_wdt_dev = NULL;
 416 +
 417 +       free_irq(wdt->irq, wdt);
 418 +       iounmap(wdt->base);
 419 +       kfree(wdt);
 420 +       return 0;
 421 +}
 422 +
 423 +
 424 +static struct platform_driver cns3xxx_wdt_driver = {
 425 +       .probe          = cns3xxx_wdt_probe,
 426 +       .remove         = __devexit_p(cns3xxx_wdt_remove),
 427 +       .shutdown       = cns3xxx_wdt_shutdown,
 428 +       .driver         = {
 429 +               .owner  = THIS_MODULE,
 430 +               .name   = "cns3xxx-wdt",
 431 +       },
 432 +};
 433 +
 434 +static char banner[] __initdata = KERN_INFO
 435 +               "CNS3XXX Watchdog Timer, noboot=%d margin=%d sec (nowayout= %d)\n";
 436 +
 437 +static int __init cns3xxx_wdt_init(void)
 438 +{
 439 +       /*
 440 +        * Check that the margin value is within it's range;
 441 +        * if not reset to the default
 442 +        */
 443 +       if (cns3xxx_wdt_set_heartbeat(cns3xxx_margin)) {
 444 +               cns3xxx_wdt_set_heartbeat(TIMER_MARGIN);
 445 +               printk(KERN_INFO "cns3xxx_margin value must be 0 < cns3xxx_margin < 65536, using %d\n",
 446 +                       TIMER_MARGIN);
 447 +       }
 448 +
 449 +       printk(banner, cns3xxx_noboot, cns3xxx_margin, nowayout);
 450 +
 451 +       spin_lock_init(&wdt_lock);
 452 +
 453 +       return platform_driver_register(&cns3xxx_wdt_driver);
 454 +}
 455 +
 456 +static void __exit cns3xxx_wdt_exit(void)
 457 +{
 458 +       platform_driver_unregister(&cns3xxx_wdt_driver);
 459 +}
 460 +
 461 +module_init(cns3xxx_wdt_init);
 462 +module_exit(cns3xxx_wdt_exit);
 463 +
 464 +MODULE_AUTHOR("Scott Shu");
 465 +MODULE_DESCRIPTION("CNS3XXX Watchdog Device Driver");
 466 +MODULE_LICENSE("GPL");
 467 +MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
 468 +MODULE_ALIAS("platform:cns3xxx-wdt");
 469 --- a/drivers/watchdog/Kconfig
 470 +++ b/drivers/watchdog/Kconfig
 471 @@ -231,6 +231,15 @@ config DAVINCI_WATCHDOG
 472           NOTE: once enabled, this timer cannot be disabled.
 473           Say N if you are unsure.
 474
 475 +config CNS3XXX_WATCHDOG
 476 +       tristate "CNS3XXX watchdog"
 477 +       depends on ARCH_CNS3XXX && LOCAL_TIMERS
 478 +       help
 479 +         Watchdog timer embedded into the CNS3XXX SoCs system.
 480 +
 481 +         To compile this driver as a module, choose M here: the
 482 +         module will be called cns3xxx_wdt.
 483 +
 484  config ORION_WATCHDOG
 485         tristate "Orion watchdog"
 486         depends on ARCH_ORION5X || ARCH_KIRKWOOD
 487 --- a/drivers/watchdog/Makefile
 488 +++ b/drivers/watchdog/Makefile
 489 @@ -41,6 +41,7 @@ obj-$(CONFIG_EP93XX_WATCHDOG) += ep93xx_
 490  obj-$(CONFIG_PNX4008_WATCHDOG) += pnx4008_wdt.o
 491  obj-$(CONFIG_IOP_WATCHDOG) += iop_wdt.o
 492  obj-$(CONFIG_DAVINCI_WATCHDOG) += davinci_wdt.o
 493 +obj-$(CONFIG_CNS3XXX_WATCHDOG) += cns3xxx_wdt.o
 494  obj-$(CONFIG_ORION_WATCHDOG) += orion_wdt.o
 495  obj-$(CONFIG_COH901327_WATCHDOG) += coh901327_wdt.o
 496  obj-$(CONFIG_STMP3XXX_WATCHDOG) += stmp3xxx_wdt.o