omap_wdt_hardware.c

来自「Linux Kernel 2.6.9 for OMAP1710」· C语言 代码 · 共 93 行

/* 
 * drivers/char/watchdog/omap_wdt_hardware.c
 *
 * Hardware specific functions called by Watchdog Core driver OMAP platforms.
 *
 * Copyright (C) 2004 Texas Instruments, Inc. 
 * 
 * This package 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. 
 * 
 * THIS PACKAGE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR 
 * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED 
 * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE. 
 */


#include <asm/io.h>
#include <linux/delay.h>
#include <asm/hardware/clock.h>
#include "omap_wdt_core.h"
#include "omap_wdt_hardware.h"

static unsigned int wdt_trgr_pattern = 0x1234;

unsigned int omap_wdt_boot_status(void)
{
	return WDT_GET_BOOTSTATUS();
}
void
omap_wdt_ping(void)
{
	/* wait for posted write to complete */
	while ((omap_readl(OMAP_WATCHDOG_WPS)) & 0x08) ;       
        wdt_trgr_pattern = ~wdt_trgr_pattern;
	omap_writel(wdt_trgr_pattern, (OMAP_WATCHDOG_TGR));
	
	/* wait for posted write to complete */
	while ((omap_readl(OMAP_WATCHDOG_WPS)) & 0x08) ;       
	return;
}

void
omap_wdt_enable(void)
{
        /* Sequence to enable the watchdog */
	omap_writel(0xBBBB, OMAP_WATCHDOG_SPR);
	while ((omap_readl(OMAP_WATCHDOG_WPS)) & 0x10) ;
	omap_writel(0x4444, OMAP_WATCHDOG_SPR);
	while ((omap_readl(OMAP_WATCHDOG_WPS)) & 0x10) ;
	return;
}
void
omap_wdt_disable(void)
{
	 /* sequence required to disable watchdog */
	omap_writel(0xAAAA, OMAP_WATCHDOG_SPR); /* TIMER_MODE */
	while (omap_readl(OMAP_WATCHDOG_WPS) & 0x10) ;
	omap_writel(0x5555, OMAP_WATCHDOG_SPR); /* TIMER_MODE */
	while (omap_readl(OMAP_WATCHDOG_WPS) & 0x10) ;
	return;
}
void omap_wldr_write(unsigned long data)
{
	data=GET_WLDR_VAL(data);
    	omap_writel(data, (OMAP_WATCHDOG_LDR));
    	while ((omap_readl(OMAP_WATCHDOG_WPS)) & 0x04) ;
}
void omap_wdt_get_time_margin (int * min, int * max)
{
	*min = 1;
#ifdef CONFIG_ARCH_OMAP
	*max = 32;
#endif 
	*max = 10000;
}
       	
/* Hardware specific initializations */
int omap_wdt_start(int timer_margin)
{
#ifdef CONFIG_ARCH_OMAP
	struct clk *clk_info = clk_get(0,"armwdt_ck");
	WDT_CK_ENABLE();	/* Enable the clock */
	omap_wdt_disable();
	if (timer_margin < 1 || timer_margin > 32){
		timer_margin = 32;
	}
#elif CONFIG_ARCH_OMAP24XX
	WDT_CK_ENABLE();
#endif
	return timer_margin;
}