Commit 9bf13062 authored Jul 27, 2020 by Chris Packham Committed by Alexandre Belloni Aug 05, 2020

rtc: ds1307: provide an indication that the watchdog has fired

There's not much feedback when the ds1388 watchdog fires. Generally it
yanks on the reset line and the board reboots. Capture the fact that the
watchdog has fired in the past so that userspace can retrieve it via
WDIOC_GETBOOTSTATUS. This should help distinguish a watchdog triggered
reset from a power interruption.

Signed-off-by: Chris Packham <chris.packham@alliedtelesis.co.nz>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Link: https://lore.kernel.org/r/20200727034615.19755-1-chris.packham@alliedtelesis.co.nz

parent 3d6cfb36

drivers/rtc/rtc-ds1307.c

+6 −0

Original line number	Diff line number	Diff line
		@@ -1668,6 +1668,8 @@ static const struct watchdog_ops ds1388_wdt_ops = {
		static void ds1307_wdt_register(struct ds1307 *ds1307)
		{
		struct watchdog_device *wdt;
		int err;
		int val;

		if (ds1307->type != ds_1388)
		return;
		@@ -1676,6 +1678,10 @@ static void ds1307_wdt_register(struct ds1307 *ds1307)
		if (!wdt)
		return;

		err = regmap_read(ds1307->regmap, DS1388_REG_FLAG, &val);
		if (!err && val & DS1388_BIT_WF)
		wdt->bootstatus = WDIOF_CARDRESET;

		wdt->info = &ds1388_wdt_info;
		wdt->ops = &ds1388_wdt_ops;
		wdt->timeout = 99;