u-boot/drivers/watchdog/at91sam9_wdt.c
Tom Rini 83d290c56f SPDX: Convert all of our single license tags to Linux Kernel style
When U-Boot started using SPDX tags we were among the early adopters and
there weren't a lot of other examples to borrow from.  So we picked the
area of the file that usually had a full license text and replaced it
with an appropriate SPDX-License-Identifier: entry.  Since then, the
Linux Kernel has adopted SPDX tags and they place it as the very first
line in a file (except where shebangs are used, then it's second line)
and with slightly different comment styles than us.

In part due to community overlap, in part due to better tag visibility
and in part for other minor reasons, switch over to that style.

This commit changes all instances where we have a single declared
license in the tag as both the before and after are identical in tag
contents.  There's also a few places where I found we did not have a tag
and have introduced one.

Signed-off-by: Tom Rini <trini@konsulko.com>
2018-05-07 09:34:12 -04:00

80 lines
2 KiB
C

// SPDX-License-Identifier: GPL-2.0+
/*
* [origin: Linux kernel drivers/watchdog/at91sam9_wdt.c]
*
* Watchdog driver for Atmel AT91SAM9x processors.
*
* Copyright (C) 2008 Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
* Copyright (C) 2008 Renaud CERRATO r.cerrato@til-technologies.fr
*/
/*
* The Watchdog Timer Mode Register can be only written to once. If the
* timeout need to be set from U-Boot, be sure that the bootstrap doesn't
* write to this register. Inform Linux to it too
*/
#include <common.h>
#include <watchdog.h>
#include <asm/arch/hardware.h>
#include <asm/io.h>
#include <asm/arch/at91_wdt.h>
/*
* AT91SAM9 watchdog runs a 12bit counter @ 256Hz,
* use this to convert a watchdog
* value from/to milliseconds.
*/
#define ms_to_ticks(t) (((t << 8) / 1000) - 1)
#define ticks_to_ms(t) (((t + 1) * 1000) >> 8)
/* Hardware timeout in seconds */
#if !defined(CONFIG_AT91_HW_WDT_TIMEOUT)
#define WDT_HW_TIMEOUT 2
#else
#define WDT_HW_TIMEOUT CONFIG_AT91_HW_WDT_TIMEOUT
#endif
/*
* Set the watchdog time interval in 1/256Hz (write-once)
* Counter is 12 bit.
*/
static int at91_wdt_settimeout(unsigned int timeout)
{
unsigned int reg;
at91_wdt_t *wd = (at91_wdt_t *) ATMEL_BASE_WDT;
/* Check if disabled */
if (readl(&wd->mr) & AT91_WDT_MR_WDDIS) {
printf("sorry, watchdog is disabled\n");
return -1;
}
/*
* All counting occurs at SLOW_CLOCK / 128 = 256 Hz
*
* Since WDV is a 12-bit counter, the maximum period is
* 4096 / 256 = 16 seconds.
*/
reg = AT91_WDT_MR_WDRSTEN /* causes watchdog reset */
| AT91_WDT_MR_WDDBGHLT /* disabled in debug mode */
| AT91_WDT_MR_WDD(0xfff) /* restart at any time */
| AT91_WDT_MR_WDV(timeout); /* timer value */
writel(reg, &wd->mr);
return 0;
}
void hw_watchdog_reset(void)
{
at91_wdt_t *wd = (at91_wdt_t *) ATMEL_BASE_WDT;
writel(AT91_WDT_CR_WDRSTT | AT91_WDT_CR_KEY, &wd->cr);
}
void hw_watchdog_init(void)
{
/* 16 seconds timer, resets enabled */
at91_wdt_settimeout(ms_to_ticks(WDT_HW_TIMEOUT * 1000));
}