u-boot/drivers/watchdog/imx_watchdog.c

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/*
* watchdog.c - driver for i.mx on-chip watchdog
*
* Licensed under the GPL-2 or later.
*/
#include <common.h>
#include <asm/io.h>
#include <watchdog.h>
#include <asm/arch/imx-regs.h>
struct watchdog_regs {
u16 wcr; /* Control */
u16 wsr; /* Service */
u16 wrsr; /* Reset Status */
};
#define WCR_WDZST 0x01
#define WCR_WDBG 0x02
#define WCR_WDE 0x04 /* WDOG enable */
#define WCR_WDT 0x08
#define WCR_WDW 0x80
#define SET_WCR_WT(x) (x << 8)
#ifdef CONFIG_IMX_WATCHDOG
void hw_watchdog_reset(void)
{
struct watchdog_regs *wdog = (struct watchdog_regs *)WDOG1_BASE_ADDR;
writew(0x5555, &wdog->wsr);
writew(0xaaaa, &wdog->wsr);
}
void hw_watchdog_init(void)
{
struct watchdog_regs *wdog = (struct watchdog_regs *)WDOG1_BASE_ADDR;
u16 timeout;
/*
* The timer watchdog can be set between
* 0.5 and 128 Seconds. If not defined
* in configuration file, sets 128 Seconds
*/
#ifndef CONFIG_WATCHDOG_TIMEOUT_MSECS
#define CONFIG_WATCHDOG_TIMEOUT_MSECS 128000
#endif
timeout = (CONFIG_WATCHDOG_TIMEOUT_MSECS / 500) - 1;
writew(WCR_WDZST | WCR_WDBG | WCR_WDE | WCR_WDT |
WCR_WDW | SET_WCR_WT(timeout), &wdog->wcr);
hw_watchdog_reset();
}
#endif
void reset_cpu(ulong addr)
{
struct watchdog_regs *wdog = (struct watchdog_regs *)WDOG1_BASE_ADDR;
writew(WCR_WDE, &wdog->wcr);
writew(0x5555, &wdog->wsr);
writew(0xaaaa, &wdog->wsr); /* load minimum 1/2 second timeout */
while (1) {
/*
* spin for .5 seconds before reset
*/
}
}