release/src-rt-6.x.4708/linux/linux-2.6.36/arch/arm/plat-samsung/include/plat/watchdog-reset.h

   1 /* arch/arm/plat-s3c/include/plat/watchdog-reset.h
   2  *
   3  * Copyright (c) 2008 Simtec Electronics
   4  *      Ben Dooks <ben@simtec.co.uk>
   5  *
   6  * S3C2410 - System define for arch_reset() function
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License version 2 as
  10  * published by the Free Software Foundation.
  11 */
  12
  13 #include <plat/regs-watchdog.h>
  14 #include <mach/map.h>
  15
  16 #include <linux/clk.h>
  17 #include <linux/err.h>
  18 #include <linux/io.h>
  19
  20 static inline void arch_wdt_reset(void)
  21 {
  22         struct clk *wdtclk;
  23
  24         printk("arch_reset: attempting watchdog reset\n");
  25
  26         __raw_writel(0, S3C2410_WTCON);   /* disable watchdog, to be safe  */
  27
  28         wdtclk = clk_get(NULL, "watchdog");
  29         if (!IS_ERR(wdtclk)) {
  30                 clk_enable(wdtclk);
  31         } else
  32                 printk(KERN_WARNING "%s: warning: cannot get watchdog clock\n", __func__);
  33
  34         /* put initial values into count and data */
  35         __raw_writel(0x80, S3C2410_WTCNT);
  36         __raw_writel(0x80, S3C2410_WTDAT);
  37
  38         /* set the watchdog to go and reset... */
  39         __raw_writel(S3C2410_WTCON_ENABLE|S3C2410_WTCON_DIV16|S3C2410_WTCON_RSTEN |
  40                      S3C2410_WTCON_PRESCALE(0x20), S3C2410_WTCON);
  41
  42         /* wait for reset to assert... */
  43         mdelay(500);
  44
  45         printk(KERN_ERR "Watchdog reset failed to assert reset\n");
  46
  47         /* delay to allow the serial port to show the message */
  48         mdelay(50);
  49 }