u-boot/drivers/watchdog/omap_wdt.c
Heiko Schocher 988ea35501 arm, am335x: add watchdog support
Add TI OMAP 16xx & 24xx/34xx 32KHz (non-secure) watchdog support.

Signed-off-by: Heiko Schocher <hs@denx.de>
Reviewed-by: Tom Rini <trini@ti.com>
Cc: Albert Aribaud <albert.u.boot@aribaud.net>
2013-08-28 11:44:59 -04:00

121 lines
2.8 KiB
C

/*
* omap_wdt.c
*
* (C) Copyright 2013
* Heiko Schocher, DENX Software Engineering, hs@denx.de.
*
* SPDX-License-Identifier: GPL-2.0
*
* Based on:
*
* Watchdog driver for the TI OMAP 16xx & 24xx/34xx 32KHz (non-secure) watchdog
*
* commit 2d991a164a61858012651e13c59521975504e260
* Author: Bill Pemberton <wfp5p@virginia.edu>
* Date: Mon Nov 19 13:21:41 2012 -0500
*
* watchdog: remove use of __devinit
*
* CONFIG_HOTPLUG is going away as an option so __devinit is no longer
* needed.
*
* Author: MontaVista Software, Inc.
* <gdavis@mvista.com> or <source@mvista.com>
*
* History:
*
* 20030527: George G. Davis <gdavis@mvista.com>
* Initially based on linux-2.4.19-rmk7-pxa1/drivers/char/sa1100_wdt.c
* (c) Copyright 2000 Oleg Drokin <green@crimea.edu>
* Based on SoftDog driver by Alan Cox <alan@lxorguk.ukuu.org.uk>
*
* Copyright (c) 2004 Texas Instruments.
* 1. Modified to support OMAP1610 32-KHz watchdog timer
* 2. Ported to 2.6 kernel
*
* Copyright (c) 2005 David Brownell
* Use the driver model and standard identifiers; handle bigger timeouts.
*/
#include <common.h>
#include <watchdog.h>
#include <asm/arch/hardware.h>
#include <asm/io.h>
#include <asm/processor.h>
#include <asm/arch/cpu.h>
/* Hardware timeout in seconds */
#define WDT_HW_TIMEOUT 60
static unsigned int wdt_trgr_pattern = 0x1234;
void hw_watchdog_reset(void)
{
struct wd_timer *wdt = (struct wd_timer *)WDT_BASE;
/* wait for posted write to complete */
while ((readl(&wdt->wdtwwps)) & WDT_WWPS_PEND_WTGR)
;
wdt_trgr_pattern = ~wdt_trgr_pattern;
writel(wdt_trgr_pattern, &wdt->wdtwtgr);
/* wait for posted write to complete */
while ((readl(&wdt->wdtwwps) & WDT_WWPS_PEND_WTGR))
;
}
static int omap_wdt_set_timeout(unsigned int timeout)
{
struct wd_timer *wdt = (struct wd_timer *)WDT_BASE;
u32 pre_margin = GET_WLDR_VAL(timeout);
/* just count up at 32 KHz */
while (readl(&wdt->wdtwwps) & WDT_WWPS_PEND_WLDR)
;
writel(pre_margin, &wdt->wdtwldr);
while (readl(&wdt->wdtwwps) & WDT_WWPS_PEND_WLDR)
;
return 0;
}
void hw_watchdog_init(void)
{
struct wd_timer *wdt = (struct wd_timer *)WDT_BASE;
/* initialize prescaler */
while (readl(&wdt->wdtwwps) & WDT_WWPS_PEND_WCLR)
;
writel(WDT_WCLR_PRE | (PTV << WDT_WCLR_PTV_OFF), &wdt->wdtwclr);
while (readl(&wdt->wdtwwps) & WDT_WWPS_PEND_WCLR)
;
omap_wdt_set_timeout(WDT_HW_TIMEOUT);
/* Sequence to enable the watchdog */
writel(0xBBBB, &wdt->wdtwspr);
while ((readl(&wdt->wdtwwps)) & WDT_WWPS_PEND_WSPR)
;
writel(0x4444, &wdt->wdtwspr);
while ((readl(&wdt->wdtwwps)) & WDT_WWPS_PEND_WSPR)
;
}
void hw_watchdog_disable(void)
{
struct wd_timer *wdt = (struct wd_timer *)WDT_BASE;
/*
* Disable watchdog
*/
writel(0xAAAA, &wdt->wdtwspr);
while (readl(&wdt->wdtwwps) != 0x0)
;
writel(0x5555, &wdt->wdtwspr);
while (readl(&wdt->wdtwwps) != 0x0)
;
}