android_kernel_motorola_sm6225/include/asm-arm/arch-s3c2410/system.h
Ben Dooks ff44b49b55 [ARM] 4722/1: S3C24XX: Improve output if watchdog reset fails
If the watchdog reset fails and we decided to take the jump
to zero approach, allow 50ms for the UARTS to drain the FIFOs
before calling into a bootloader that may flush the output.

Also reduece the waits and the timeout values as 5 seconds is
rather long.

Signed-off-by: Ben Dooks <ben-linux@fluff.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2008-01-28 13:20:49 +00:00

102 lines
2.4 KiB
C

/* linux/include/asm-arm/arch-s3c2410/system.h
*
* Copyright (c) 2003 Simtec Electronics
* Ben Dooks <ben@simtec.co.uk>
*
* S3C2410 - System function defines and includes
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <asm/hardware.h>
#include <asm/io.h>
#include <asm/arch/map.h>
#include <asm/arch/idle.h>
#include <asm/arch/reset.h>
#include <asm/plat-s3c/regs-watchdog.h>
#include <asm/arch/regs-clock.h>
#include <linux/clk.h>
#include <linux/err.h>
void (*s3c24xx_idle)(void);
void (*s3c24xx_reset_hook)(void);
void s3c24xx_default_idle(void)
{
unsigned long tmp;
int i;
/* idle the system by using the idle mode which will wait for an
* interrupt to happen before restarting the system.
*/
/* Warning: going into idle state upsets jtag scanning */
__raw_writel(__raw_readl(S3C2410_CLKCON) | S3C2410_CLKCON_IDLE,
S3C2410_CLKCON);
/* the samsung port seems to do a loop and then unset idle.. */
for (i = 0; i < 50; i++) {
tmp += __raw_readl(S3C2410_CLKCON); /* ensure loop not optimised out */
}
/* this bit is not cleared on re-start... */
__raw_writel(__raw_readl(S3C2410_CLKCON) & ~S3C2410_CLKCON_IDLE,
S3C2410_CLKCON);
}
static void arch_idle(void)
{
if (s3c24xx_idle != NULL)
(s3c24xx_idle)();
else
s3c24xx_default_idle();
}
static void
arch_reset(char mode)
{
struct clk *wdtclk;
if (mode == 's') {
cpu_reset(0);
}
if (s3c24xx_reset_hook)
s3c24xx_reset_hook();
printk("arch_reset: attempting watchdog reset\n");
__raw_writel(0, S3C2410_WTCON); /* disable watchdog, to be safe */
wdtclk = clk_get(NULL, "watchdog");
if (!IS_ERR(wdtclk)) {
clk_enable(wdtclk);
} else
printk(KERN_WARNING "%s: warning: cannot get watchdog clock\n", __func__);
/* put initial values into count and data */
__raw_writel(0x80, S3C2410_WTCNT);
__raw_writel(0x80, S3C2410_WTDAT);
/* set the watchdog to go and reset... */
__raw_writel(S3C2410_WTCON_ENABLE|S3C2410_WTCON_DIV16|S3C2410_WTCON_RSTEN |
S3C2410_WTCON_PRESCALE(0x20), S3C2410_WTCON);
/* wait for reset to assert... */
mdelay(500);
printk(KERN_ERR "Watchdog reset failed to assert reset\n");
/* delay to allow the serial port to show the message */
mdelay(50);
/* we'll take a jump through zero as a poor second */
cpu_reset(0);
}