include/asm-arm/arch-s3c2410/system.h

   1 /* linux/include/asm-arm/arch-s3c2410/system.h
   2  *
   3  * Copyright (c) 2003 Simtec Electronics
   4  *      Ben Dooks <ben@simtec.co.uk>
   5  *
   6  * S3C2410 - System function defines and includes
   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 <asm/hardware.h>
  14 #include <asm/io.h>
  15
  16 #include <asm/arch/map.h>
  17 #include <asm/arch/idle.h>
  18 #include <asm/arch/reset.h>
  19
  20 #include <asm/plat-s3c/regs-watchdog.h>
  21 #include <asm/arch/regs-clock.h>
  22
  23 void (*s3c24xx_idle)(void);
  24 void (*s3c24xx_reset_hook)(void);
  25
  26 void s3c24xx_default_idle(void)
  27 {
  28         unsigned long tmp;
  29         int i;
  30
  31         /* idle the system by using the idle mode which will wait for an
  32          * interrupt to happen before restarting the system.
  33          */
  34
  35         /* Warning: going into idle state upsets jtag scanning */
  36
  37         __raw_writel(__raw_readl(S3C2410_CLKCON) | S3C2410_CLKCON_IDLE,
  38                      S3C2410_CLKCON);
  39
  40         /* the samsung port seems to do a loop and then unset idle.. */
  41         for (i = 0; i < 50; i++) {
  42                 tmp += __raw_readl(S3C2410_CLKCON); /* ensure loop not optimised out */
  43         }
  44
  45         /* this bit is not cleared on re-start... */
  46
  47         __raw_writel(__raw_readl(S3C2410_CLKCON) & ~S3C2410_CLKCON_IDLE,
  48                      S3C2410_CLKCON);
  49 }
  50
  51 static void arch_idle(void)
  52 {
  53         if (s3c24xx_idle != NULL)
  54                 (s3c24xx_idle)();
  55         else
  56                 s3c24xx_default_idle();
  57 }
  58
  59 static void
  60 arch_reset(char mode)
  61 {
  62         if (mode == 's') {
  63                 cpu_reset(0);
  64         }
  65
  66         if (s3c24xx_reset_hook)
  67                 s3c24xx_reset_hook();
  68
  69         printk("arch_reset: attempting watchdog reset\n");
  70
  71         __raw_writel(0, S3C2410_WTCON);   /* disable watchdog, to be safe  */
  72
  73         /* put initial values into count and data */
  74         __raw_writel(0x100, S3C2410_WTCNT);
  75         __raw_writel(0x100, S3C2410_WTDAT);
  76
  77         /* set the watchdog to go and reset... */
  78         __raw_writel(S3C2410_WTCON_ENABLE|S3C2410_WTCON_DIV16|S3C2410_WTCON_RSTEN |
  79                      S3C2410_WTCON_PRESCALE(0x20), S3C2410_WTCON);
  80
  81         /* wait for reset to assert... */
  82         mdelay(5000);
  83
  84         printk(KERN_ERR "Watchdog reset failed to assert reset\n");
  85
  86         /* we'll take a jump through zero as a poor second */
  87         cpu_reset(0);
  88 }