drivers/watchdog/rk29_wdt.c

   1 /* linux/drivers/watchdog/rk29_wdt.c
   2  *
   3  * Copyright (C) 2011 ROCKCHIP, Inc.
   4  *      hhb@rock-chips.com
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 2 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program; if not, write to the Free Software
  18  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  19 */
  20
  21
  22 #include <linux/module.h>
  23 #include <linux/moduleparam.h>
  24 #include <linux/types.h>
  25 #include <linux/timer.h>
  26 #include <linux/miscdevice.h>
  27 #include <linux/watchdog.h>
  28 #include <linux/fs.h>
  29 #include <linux/init.h>
  30 #include <linux/platform_device.h>
  31 #include <linux/interrupt.h>
  32 #include <linux/clk.h>
  33 #include <linux/uaccess.h>
  34 #include <linux/io.h>
  35 #ifndef CONFIG_ARM64
  36 #include <asm/mach/map.h>
  37 #endif
  38 #ifdef CONFIG_OF
  39 #include <linux/of.h>
  40 #endif
  41
  42
  43 /* RK29 registers define */
  44 #define RK29_WDT_CR     0X00
  45 #define RK29_WDT_TORR   0X04
  46 #define RK29_WDT_CCVR   0X08
  47 #define RK29_WDT_CRR    0X0C
  48 #define RK29_WDT_STAT   0X10
  49 #define RK29_WDT_EOI    0X14
  50
  51 #define RK29_WDT_EN     1
  52 #define RK29_RESPONSE_MODE      1
  53 #define RK29_RESET_PULSE    4
  54
  55 //THAT wdt's clock is 24MHZ
  56 #define RK29_WDT_2730US         0
  57 #define RK29_WDT_5460US         1
  58 #define RK29_WDT_10920US        2
  59 #define RK29_WDT_21840US        3
  60 #define RK29_WDT_43680US        4
  61 #define RK29_WDT_87360US        5
  62 #define RK29_WDT_174720US       6
  63 #define RK29_WDT_349440US       7
  64 #define RK29_WDT_698880US       8
  65 #define RK29_WDT_1397760US      9
  66 #define RK29_WDT_2795520US      10
  67 #define RK29_WDT_5591040US      11
  68 #define RK29_WDT_11182080US     12
  69 #define RK29_WDT_22364160US     13
  70 #define RK29_WDT_44728320US     14
  71 #define RK29_WDT_89456640US     15
  72
  73 /*
  74 #define CONFIG_RK29_WATCHDOG_ATBOOT             (1)
  75 #define CONFIG_RK29_WATCHDOG_DEFAULT_TIME       10      //unit second
  76 #define CONFIG_RK29_WATCHDOG_DEBUG      1
  77 */
  78
  79 static int nowayout     = WATCHDOG_NOWAYOUT;
  80 static int tmr_margin   = 100;//CONFIG_RK29_WATCHDOG_DEFAULT_TIME;
  81 #ifdef CONFIG_RK29_WATCHDOG_ATBOOT
  82 static int tmr_atboot   = 1;
  83 #else
  84 static int tmr_atboot   = 0;
  85 #endif
  86
  87 static int soft_noboot;
  88
  89 #ifdef CONFIG_RK29_WATCHDOG_DEBUG
  90 static int debug        = 1;
  91 #else
  92 static int debug        = 0;
  93 #endif
  94
  95 module_param(tmr_margin,  int, 0);
  96 module_param(tmr_atboot,  int, 0);
  97 module_param(nowayout,    int, 0);
  98 module_param(soft_noboot, int, 0);
  99 module_param(debug,       int, 0);
 100
 101 MODULE_PARM_DESC(tmr_margin, "Watchdog tmr_margin in seconds. default="
 102                 __MODULE_STRING(CONFIG_RK29_WATCHDOG_DEFAULT_TIME) ")");
 103 MODULE_PARM_DESC(tmr_atboot,
 104                 "Watchdog is started at boot time if set to 1, default="
 105                         __MODULE_STRING(CONFIG_RK29_WATCHDOG_ATBOOT));
 106 MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="
 107                         __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
 108 MODULE_PARM_DESC(soft_noboot, "Watchdog action, set to 1 to ignore reboots, "
 109                         "0 to reboot (default depends on ONLY_TESTING)");
 110 MODULE_PARM_DESC(debug, "Watchdog debug, set to >1 for debug, (default 0)");
 111
 112
 113 static unsigned long open_lock;
 114 static struct device    *wdt_dev;       /* platform device attached to */
 115 static struct resource  *wdt_mem;
 116 static struct resource  *wdt_irq;
 117 static struct clk       *wdt_clock;
 118 static void __iomem     *wdt_base;
 119 static char              expect_close;
 120
 121
 122 /* watchdog control routines */
 123
 124 #define DBG(msg...) do { \
 125         if (debug) \
 126                 printk(KERN_INFO msg); \
 127         } while (0)
 128
 129 #ifdef CONFIG_ARM64
 130 #define wdt_writel(v, offset) do { \
 131         writel_relaxed(v, wdt_base + offset);\
 132         dsb(sy);\
 133         } while (0)
 134 #else
 135 #define wdt_writel(v, offset) do { \
 136         writel_relaxed(v, wdt_base + offset);\
 137         dsb();\
 138         } while (0)
 139 #endif
 140
 141 /* functions */
 142 void rk29_wdt_keepalive(void)
 143 {
 144         if (wdt_base)
 145                 wdt_writel(0x76, RK29_WDT_CRR);
 146 }
 147
 148 static void __rk29_wdt_stop(void)
 149 {
 150         rk29_wdt_keepalive();    //feed dog
 151         wdt_writel(0x0a, RK29_WDT_CR);
 152 }
 153
 154 void rk29_wdt_stop(void)
 155 {
 156         __rk29_wdt_stop();
 157         clk_disable_unprepare(wdt_clock);
 158 }
 159
 160 /* timeout unit second */
 161 int rk29_wdt_set_heartbeat(int timeout)
 162 {
 163         unsigned int count = 0;
 164         unsigned int torr = 0, acc = 1, maxtime = 0;
 165         unsigned int freq = clk_get_rate(wdt_clock);
 166
 167         if (timeout < 1)
 168                 return -EINVAL;
 169         //0x80000000 is the max count of watch dog
 170         maxtime = 0x80000000 / freq + 1;
 171         if(timeout > maxtime)
 172                 timeout = maxtime;
 173
 174         count = timeout * freq;
 175         count /= 0x10000;
 176
 177         while(acc < count){
 178                 acc *= 2;
 179                 torr++;
 180         }
 181         if(torr > 15){
 182                 torr = 15;
 183         }
 184         DBG("%s:torr:%d, count:%d, maxtime:%d s\n", __func__, torr, count, maxtime);
 185         wdt_writel(torr, RK29_WDT_TORR);
 186         return 0;
 187 }
 188
 189 void rk29_wdt_start(void)
 190 {
 191         unsigned long wtcon;
 192         clk_prepare_enable(wdt_clock);
 193         rk29_wdt_set_heartbeat(tmr_margin);
 194         wtcon = (RK29_WDT_EN << 0) | (RK29_RESPONSE_MODE << 1) | (RK29_RESET_PULSE << 2);
 195         wdt_writel(wtcon, RK29_WDT_CR);
 196 }
 197
 198 /*
 199  *      /dev/watchdog handling
 200  */
 201
 202 static int rk29_wdt_open(struct inode *inode, struct file *file)
 203 {
 204         DBG("%s\n", __func__);
 205         if (test_and_set_bit(0, &open_lock))
 206                 return -EBUSY;
 207
 208         if (nowayout)
 209                 __module_get(THIS_MODULE);
 210
 211         expect_close = 0;
 212
 213         /* start the timer */
 214         rk29_wdt_start();
 215         return nonseekable_open(inode, file);
 216 }
 217
 218 static int rk29_wdt_release(struct inode *inode, struct file *file)
 219 {
 220         /*
 221          *      Shut off the timer.
 222          *      Lock it in if it's a module and we set nowayout
 223          */
 224         DBG("%s\n", __func__);
 225         if (expect_close == 42)
 226                 rk29_wdt_stop();
 227         else {
 228                 dev_err(wdt_dev, "Unexpected close, not stopping watchdog\n");
 229                 rk29_wdt_keepalive();
 230         }
 231         expect_close = 0;
 232         clear_bit(0, &open_lock);
 233         return 0;
 234 }
 235
 236 static ssize_t rk29_wdt_write(struct file *file, const char __user *data,
 237                                 size_t len, loff_t *ppos)
 238 {
 239         /*
 240          *      Refresh the timer.
 241          */
 242         DBG("%s\n", __func__);
 243         if (len) {
 244                 if (!nowayout) {
 245                         size_t i;
 246
 247                         /* In case it was set long ago */
 248                         expect_close = 0;
 249
 250                         for (i = 0; i != len; i++) {
 251                                 char c;
 252
 253                                 if (get_user(c, data + i))
 254                                         return -EFAULT;
 255                                 if (c == 'V')
 256                                         expect_close = 42;
 257                         }
 258                 }
 259                 rk29_wdt_keepalive();
 260         }
 261         return len;
 262 }
 263
 264 #define OPTIONS (WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE)
 265
 266 static const struct watchdog_info rk29_wdt_ident = {
 267         .options          =     OPTIONS,
 268         .firmware_version =     0,
 269         .identity         =     "rk29 Watchdog",
 270 };
 271
 272
 273 static long rk29_wdt_ioctl(struct file *file,   unsigned int cmd,
 274                                                         unsigned long arg)
 275 {
 276         void __user *argp = (void __user *)arg;
 277         int __user *p = argp;
 278         int new_margin;
 279         DBG("%s\n", __func__);
 280         switch (cmd) {
 281         case WDIOC_GETSUPPORT:
 282                 return copy_to_user(argp, &rk29_wdt_ident,
 283                         sizeof(rk29_wdt_ident)) ? -EFAULT : 0;
 284         case WDIOC_GETSTATUS:
 285         case WDIOC_GETBOOTSTATUS:
 286                 return put_user(0, p);
 287         case WDIOC_KEEPALIVE:
 288                 DBG("%s:rk29_wdt_keepalive\n", __func__);
 289                 rk29_wdt_keepalive();
 290                 return 0;
 291         case WDIOC_SETTIMEOUT:
 292                 if (get_user(new_margin, p))
 293                         return -EFAULT;
 294                 if (rk29_wdt_set_heartbeat(new_margin))
 295                         return -EINVAL;
 296                 rk29_wdt_keepalive();
 297                 return put_user(tmr_margin, p);
 298         case WDIOC_GETTIMEOUT:
 299                 return put_user(tmr_margin, p);
 300         default:
 301                 return -ENOTTY;
 302         }
 303 }
 304
 305
 306
 307 /* kernel interface */
 308
 309 static const struct file_operations rk29_wdt_fops = {
 310         .owner          = THIS_MODULE,
 311         .llseek         = no_llseek,
 312         .write          = rk29_wdt_write,
 313         .unlocked_ioctl = rk29_wdt_ioctl,
 314         .open           = rk29_wdt_open,
 315         .release        = rk29_wdt_release,
 316 };
 317
 318 static struct miscdevice rk29_wdt_miscdev = {
 319         .minor          = WATCHDOG_MINOR,
 320         .name           = "watchdog",
 321         .fops           = &rk29_wdt_fops,
 322 };
 323
 324
 325 /* interrupt handler code */
 326
 327 static irqreturn_t rk29_wdt_irq_handler(int irqno, void *param)
 328 {
 329         DBG("RK29_wdt:watchdog timer expired (irq)\n");
 330         rk29_wdt_keepalive();
 331         return IRQ_HANDLED;
 332 }
 333
 334
 335 /* device interface */
 336
 337 static int rk29_wdt_probe(struct platform_device *pdev)
 338 {
 339         struct resource *res;
 340         struct device *dev;
 341         int started = 0;
 342         int ret, val;
 343
 344         dev = &pdev->dev;
 345         wdt_dev = &pdev->dev;
 346
 347         /* get the memory region for the watchdog timer */
 348         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 349         if (res == NULL) {
 350                 dev_err(dev, "no memory resource specified\n");
 351                 return -ENOENT;
 352         }
 353
 354         wdt_base = devm_request_and_ioremap(&pdev->dev, res);
 355         if (wdt_base == NULL) {
 356                 dev_err(dev, "failed to ioremap() region\n");
 357                 return -EINVAL;
 358         }
 359
 360 #ifdef CONFIG_OF
 361         if(!of_property_read_u32(pdev->dev.of_node, "rockchip,atboot", &val))
 362                 tmr_atboot = val;
 363         else
 364                 tmr_atboot = 0;
 365
 366         if(!of_property_read_u32(pdev->dev.of_node, "rockchip,timeout", &val))
 367                 tmr_margin = val;
 368         else
 369                 tmr_margin = 0;
 370
 371         if(!of_property_read_u32(pdev->dev.of_node, "rockchip,debug", &val))
 372                 debug = val;
 373         else
 374                 debug = 0;
 375         DBG("probe: mapped wdt_base=%p\n", wdt_base);
 376
 377         of_property_read_u32(pdev->dev.of_node, "rockchip,irq", &val);
 378 #endif
 379
 380 #ifdef CONFIG_RK29_FEED_DOG_BY_INTE
 381         val = 1;
 382 #endif
 383         //printk("atboot:%d, timeout:%ds, debug:%d, irq:%d\n", tmr_atboot, tmr_margin, debug, val);
 384
 385         if(val == 1) {
 386                 wdt_irq = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
 387                 if (wdt_irq == NULL) {
 388                         dev_err(dev, "no irq resource specified\n");
 389                         return -ENOENT;
 390                 }
 391
 392                 ret = request_irq(wdt_irq->start, rk29_wdt_irq_handler, 0, pdev->name, pdev);
 393                 if (ret != 0) {
 394                         dev_err(dev, "failed to install irq (%d)\n", ret);
 395                         return ret;
 396                 }
 397         }
 398
 399         wdt_clock = devm_clk_get(&pdev->dev, "pclk_wdt");
 400         if (IS_ERR(wdt_clock)) {
 401                 dev_err(dev, "failed to find watchdog clock source\n");
 402                 ret = PTR_ERR(wdt_clock);
 403                 goto err_irq;
 404         }
 405
 406         ret = misc_register(&rk29_wdt_miscdev);
 407         if (ret) {
 408                 dev_err(dev, "cannot register miscdev on minor=%d (%d)\n",
 409                         WATCHDOG_MINOR, ret);
 410                 goto err_irq;
 411         }
 412         if (tmr_atboot && started == 0) {
 413                 dev_info(dev, "starting watchdog timer\n");
 414                 rk29_wdt_start();
 415         } else if (!tmr_atboot) {
 416                 /* if we're not enabling the watchdog, then ensure it is
 417                  * disabled if it has been left running from the bootloader
 418                  * or other source */
 419
 420                 rk29_wdt_stop();
 421         }
 422         return 0;
 423
 424 err_irq:
 425         free_irq(wdt_irq->start, pdev);
 426         return ret;
 427 }
 428
 429 static int rk29_wdt_remove(struct platform_device *dev)
 430 {
 431         wdt_mem = NULL;
 432         free_irq(wdt_irq->start, dev);
 433         wdt_irq = NULL;
 434         clk_disable_unprepare(wdt_clock);
 435         wdt_clock = NULL;
 436         misc_deregister(&rk29_wdt_miscdev);
 437         return 0;
 438 }
 439
 440 static void rk29_wdt_shutdown(struct platform_device *dev)
 441 {
 442         rk29_wdt_stop();
 443 }
 444
 445 #ifdef CONFIG_PM
 446
 447 static int rk29_wdt_suspend(struct platform_device *dev, pm_message_t state)
 448 {
 449         rk29_wdt_stop();
 450         return 0;
 451 }
 452
 453 static int rk29_wdt_resume(struct platform_device *dev)
 454 {
 455         rk29_wdt_start();
 456         return 0;
 457 }
 458
 459 #else
 460 #define rk29_wdt_suspend NULL
 461 #define rk29_wdt_resume  NULL
 462 #endif /* CONFIG_PM */
 463
 464 #ifdef CONFIG_OF
 465 static const struct of_device_id of_rk29_wdt_match[] = {
 466         { .compatible = "rockchip,watch dog" },
 467         { /* Sentinel */ }
 468 };
 469 #endif
 470 static struct platform_driver rk29_wdt_driver = {
 471         .probe          = rk29_wdt_probe,
 472         .remove         = rk29_wdt_remove,
 473         .shutdown       = rk29_wdt_shutdown,
 474         .suspend        = rk29_wdt_suspend,
 475         .resume         = rk29_wdt_resume,
 476         .driver         = {
 477                 .owner  = THIS_MODULE,
 478 #ifdef CONFIG_OF
 479                 .of_match_table = of_rk29_wdt_match,
 480 #endif
 481                 .name   = "rk29-wdt",
 482         },
 483 };
 484
 485
 486 static char banner[] __initdata =
 487         KERN_INFO "RK29 Watchdog Timer, (c) 2011 Rockchip Electronics\n";
 488
 489 static int __init watchdog_init(void)
 490 {
 491         printk(banner);
 492         return platform_driver_register(&rk29_wdt_driver);
 493 }
 494
 495 static void __exit watchdog_exit(void)
 496 {
 497         platform_driver_unregister(&rk29_wdt_driver);
 498 }
 499
 500 subsys_initcall(watchdog_init);
 501 module_exit(watchdog_exit);
 502
 503 MODULE_AUTHOR("hhb@rock-chips.com");
 504 MODULE_DESCRIPTION("RK29 Watchdog Device Driver");
 505 MODULE_LICENSE("GPL");
 506 MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
 507 MODULE_ALIAS("platform:rk29-wdt");