Subject: Fwd: [PATCH 3/8] watchdog: davinci: add GET_TIMELEFT option support

From: [email-masked] (Guenter Roeck)
Date: Sat, 16 Nov 2013 18:22:02 -0800

On 11/06/2013 03:31 AM, ivan.khoronzhuk wrote:
> Currently, the davinci watchdog can be read while counting,
> so we can add ability to report the remaining time before
> the system will reboot.
>
> Signed-off-by: Ivan Khoronzhuk <[email-masked]>
> ---
>   drivers/watchdog/davinci_wdt.c |   28 ++++++++++++++++++++++++++++
>   1 file changed, 28 insertions(+)
>
> diff --git a/drivers/watchdog/davinci_wdt.c b/drivers/watchdog/davinci_wdt.c
> index 1fc2093..6cbf2e1 100644
> --- a/drivers/watchdog/davinci_wdt.c
> +++ b/drivers/watchdog/davinci_wdt.c
> @@ -117,6 +117,33 @@ static int davinci_wdt_ping(struct watchdog_device *wdd)
>   	return 0;
>   }
>
> +static unsigned int davinci_wdt_get_timeleft(struct watchdog_device *wdd)
> +{
> +	u64 timer_counter;
> +	unsigned long freq;
> +	u32 val;
> +	struct davinci_wdt_device *davinci_wdt = watchdog_get_drvdata(wdd);
> +
> +	/* if timeout is occured then return 0 */

is -> has ?

> +	val = ioread32(davinci_wdt->base + WDTCR);
> +	if (val & WDFLAG)
> +		return 0;
> +
> +	freq = clk_get_rate(davinci_wdt->clk);
> +
> +	if (!freq) {
> +		dev_err(wdd->dev, "clock freq is not set\n");
> +		return 0;
> +	}
> +
This error check doesn't make sense to me; elsewhere the clock rate is not validated.
I would suggest to just return 0 here.

> +	timer_counter = ioread32(davinci_wdt->base + TIM12);
> +	timer_counter |= ((u64)ioread32(davinci_wdt->base + TIM34) << 32);
> +
> +	do_div(timer_counter, freq);
> +
> +	return wdd->timeout - timer_counter;
> +}
> +
>   static const struct watchdog_info davinci_wdt_info = {
>   	.options = WDIOF_KEEPALIVEPING,
>   	.identity = "DaVinci Watchdog",
> @@ -127,6 +154,7 @@ static const struct watchdog_ops davinci_wdt_ops = {
>   	.start		= davinci_wdt_start,
>   	.stop		= davinci_wdt_ping,
>   	.ping		= davinci_wdt_ping,
> +	.get_timeleft	= davinci_wdt_get_timeleft,
>   };
>
>   static int davinci_wdt_probe(struct platform_device *pdev)
>