[PATCHv7 8/8] watchdog: omap_wdt: Convert to use new core extensions

[Timo Kokkonen]

Use the new watchdog core extensions to let watchdog core take over
boot time watchdog behavior. The difference is that early-timeout-sec
device tree property becomes available for this driver and a running
watchdog is not stopped unless the core decides to stop it.

Omap watchdog is running by default in the boot up but bootloader
might have stopped it. Therefore we fill the WDOG_HW_RUNNING_AT_BOOT
bit depending on the actual watchdog state so that the watchdog core
can act properly.

Signed-off-by: Timo Kokkonen <timo.kokkonen at offcode.fi>
---
 drivers/watchdog/omap_wdt.c | 28 +++++++++++++++++++++++++++-
 1 file changed, 27 insertions(+), 1 deletion(-)

diff --git a/drivers/watchdog/omap_wdt.c b/drivers/watchdog/omap_wdt.c
index bbaf39a..7164f2e 100644
--- a/drivers/watchdog/omap_wdt.c
+++ b/drivers/watchdog/omap_wdt.c
@@ -78,6 +78,13 @@ static void omap_wdt_reload(struct omap_wdt_dev *wdev)
 	/* reloaded WCRR from WLDR */
 }
 
+static int omap_wdt_is_running(struct omap_wdt_dev *wdev)
+{
+	void __iomem *base = wdev->base;
+
+	return readl_relaxed(base + OMAP_WATCHDOG_SPR) == 0x4444;
+}
+
 static void omap_wdt_enable(struct omap_wdt_dev *wdev)
 {
 	void __iomem *base = wdev->base;
@@ -183,6 +190,7 @@ static int omap_wdt_set_timeout(struct watchdog_device *wdog,
 	omap_wdt_enable(wdev);
 	omap_wdt_reload(wdev);
 	wdog->timeout = timeout;
+	wdog->hw_heartbeat = timeout * HZ / 2;
 	mutex_unlock(&wdev->lock);
 
 	return 0;
@@ -235,12 +243,15 @@ static int omap_wdt_probe(struct platform_device *pdev)
 	omap_wdt->ops	      = &omap_wdt_ops;
 	omap_wdt->min_timeout = TIMER_MARGIN_MIN;
 	omap_wdt->max_timeout = TIMER_MARGIN_MAX;
+	omap_wdt->hw_max_timeout = TIMER_MARGIN_MAX * HZ;
+	omap_wdt->hw_features = WDOG_HW_IS_STOPPABLE;
 
 	if (timer_margin >= TIMER_MARGIN_MIN &&
 	    timer_margin <= TIMER_MARGIN_MAX)
 		omap_wdt->timeout = timer_margin;
 	else
 		omap_wdt->timeout = TIMER_MARGIN_DEFAULT;
+	omap_wdt->hw_heartbeat = omap_wdt->timeout * HZ / 2;
 
 	watchdog_set_drvdata(omap_wdt, wdev);
 	watchdog_set_nowayout(omap_wdt, nowayout);
@@ -250,6 +261,18 @@ static int omap_wdt_probe(struct platform_device *pdev)
 	pm_runtime_enable(wdev->dev);
 	pm_runtime_get_sync(wdev->dev);
 
+	if (omap_wdt_is_running(wdev))
+		omap_wdt->hw_features |= WDOG_HW_RUNNING_AT_BOOT;
+	else
+		/*
+		 * The watchdog should be stopped already by
+		 * bootloader. But unless we call disable here, the
+		 * timeout might not be set correctly on the first
+		 * start. So call disable anyway to make sure the
+		 * watchdog really is stopped properly.
+		 */
+		omap_wdt_disable(wdev);
+
 	if (pdata && pdata->read_reset_sources)
 		rs = pdata->read_reset_sources();
 	else
@@ -257,7 +280,9 @@ static int omap_wdt_probe(struct platform_device *pdev)
 	omap_wdt->bootstatus = (rs & (1 << OMAP_MPU_WD_RST_SRC_ID_SHIFT)) ?
 				WDIOF_CARDRESET : 0;
 
-	omap_wdt_disable(wdev);
+	ret = watchdog_init_params(omap_wdt, &pdev->dev);
+	if (ret)
+		goto err_init_params;
 
 	ret = watchdog_register_device(omap_wdt);
 	if (ret)
@@ -271,6 +296,7 @@ static int omap_wdt_probe(struct platform_device *pdev)
 
 	return 0;
 
+err_init_params:
 err_register_device:
 	pm_runtime_disable(wdev->dev);
 err_ioremap:
-- 
2.1.0