[PATCH v3 3/6] watchdog: davinci: add GET_TIMELEFT option support

From: Ivan Khoronzhuk
Date: Mon Nov 25 2013 - 09:06:51 EST


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 <ivan.khoronzhuk@xxxxxx>
Acked-by: Santosh Shilimkar <santosh.shilimkar@xxxxxx>
Reviewed-by: Guenter Roeck <linux@xxxxxxxxxxxx>
---
drivers/watchdog/davinci_wdt.c | 26 ++++++++++++++++++++++++++
1 file changed, 26 insertions(+)

diff --git a/drivers/watchdog/davinci_wdt.c b/drivers/watchdog/davinci_wdt.c
index 4c3f417..d342fc2 100644
--- a/drivers/watchdog/davinci_wdt.c
+++ b/drivers/watchdog/davinci_wdt.c
@@ -116,6 +116,31 @@ 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 has occured then return 0 */
+ val = ioread32(davinci_wdt->base + WDTCR);
+ if (val & WDFLAG)
+ return 0;
+
+ freq = clk_get_rate(davinci_wdt->clk);
+
+ if (!freq)
+ return 0;
+
+ 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",
@@ -126,6 +151,7 @@ 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)
--
1.7.9.5

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