diff mbox series

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

Message ID 20200724045009.7293-1-chris.packham@alliedtelesis.co.nz
State Changes Requested
Headers show
Series rtc: ds1307: provide an indication that the watchdog has fired | expand

Commit Message

Chris Packham July 24, 2020, 4:50 a.m. UTC
There's not much feedback when the ds1388 watchdog fires. Generally it
yanks on the reset line and the board reboots. To provide some feedback
indicate that the watchdog has fired in the past. This should help
distinguish a watchdog triggered reset from a power interruption.

Signed-off-by: Chris Packham <chris.packham@alliedtelesis.co.nz>
---
 drivers/rtc/rtc-ds1307.c | 8 ++++++++
 1 file changed, 8 insertions(+)

Comments

Guenter Roeck July 24, 2020, 2:32 p.m. UTC | #1
On 7/23/20 9:50 PM, Chris Packham wrote:
> There's not much feedback when the ds1388 watchdog fires. Generally it
> yanks on the reset line and the board reboots. To provide some feedback
> indicate that the watchdog has fired in the past. This should help
> distinguish a watchdog triggered reset from a power interruption.
> 
> Signed-off-by: Chris Packham <chris.packham@alliedtelesis.co.nz>
> ---
>  drivers/rtc/rtc-ds1307.c | 8 ++++++++
>  1 file changed, 8 insertions(+)
> 
> diff --git a/drivers/rtc/rtc-ds1307.c b/drivers/rtc/rtc-ds1307.c
> index 49702942bb08..431b1a50c483 100644
> --- a/drivers/rtc/rtc-ds1307.c
> +++ b/drivers/rtc/rtc-ds1307.c
> @@ -868,6 +868,14 @@ static int ds1388_wdt_start(struct watchdog_device *wdt_dev)
>  	struct ds1307 *ds1307 = watchdog_get_drvdata(wdt_dev);
>  	u8 regs[2];
>  	int ret;
> +	int val;
> +
> +	ret = regmap_read(ds1307->regmap, DS1388_REG_FLAG, &val);
> +	if (ret)
> +		return ret;
> +
> +	if (val & DS1388_BIT_WF)
> +		dev_notice(ds1307->dev, "detected watchdog alarm flag\n");
>  
>  	ret = regmap_update_bits(ds1307->regmap, DS1388_REG_FLAG,
>  				 DS1388_BIT_WF, 0);
> 

This should be reported with WDIOC_GETBOOTSTATUS / WDIOF_CARDRESET,
not as log message when starting the watchdog.

Guenter
diff mbox series

Patch

diff --git a/drivers/rtc/rtc-ds1307.c b/drivers/rtc/rtc-ds1307.c
index 49702942bb08..431b1a50c483 100644
--- a/drivers/rtc/rtc-ds1307.c
+++ b/drivers/rtc/rtc-ds1307.c
@@ -868,6 +868,14 @@  static int ds1388_wdt_start(struct watchdog_device *wdt_dev)
 	struct ds1307 *ds1307 = watchdog_get_drvdata(wdt_dev);
 	u8 regs[2];
 	int ret;
+	int val;
+
+	ret = regmap_read(ds1307->regmap, DS1388_REG_FLAG, &val);
+	if (ret)
+		return ret;
+
+	if (val & DS1388_BIT_WF)
+		dev_notice(ds1307->dev, "detected watchdog alarm flag\n");
 
 	ret = regmap_update_bits(ds1307->regmap, DS1388_REG_FLAG,
 				 DS1388_BIT_WF, 0);