clockevents: Handle tick device's resume separately

Upcoming patch will redefine possible states of a clockevent
device. The RESUME mode is a special case only for tick's
clockevent devices. In future it can be replaced by ->resume()
callback already available for clockevent devices.

Lets handle it separately so that clockevents_set_mode() only
handles states valid across all devices. This also renames
set_mode_resume() to tick_resume() to make it more explicit.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Kevin Hilman <khilman@linaro.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Preeti U Murthy <preeti@linux.vnet.ibm.com>
Cc: linaro-kernel@lists.linaro.org
Cc: linaro-networking@linaro.org
Cc: linux-arm-kernel@lists.infradead.org
Link: http://lkml.kernel.org/r/c1b0112410870f49e7bf06958e1483eac6c15e20.1425037853.git.viresh.kumar@linaro.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>

1 files changed, 21 insertions, 9 deletions

diff --git a/kernel/time/clockevents.c b/kernel/time/clockevents.c
index 489642b..1b0ea63 100644
--- a/kernel/time/clockevents.c
+++ b/kernel/time/clockevents.c
@@ -100,7 +100,7 @@ static int __clockevents_set_mode(struct clock_event_device *dev,
 	/* Transition with legacy set_mode() callback */
 	if (dev->set_mode) {
 		/* Legacy callback doesn't support new modes */
-		if (mode > CLOCK_EVT_MODE_RESUME)
+		if (mode > CLOCK_EVT_MODE_ONESHOT)
 			return -ENOSYS;
 		dev->set_mode(mode, dev);
 		return 0;
@@ -133,13 +133,6 @@ static int __clockevents_set_mode(struct clock_event_device *dev,
 			return -ENOSYS;
 		return dev->set_mode_oneshot(dev);
 
-	case CLOCK_EVT_MODE_RESUME:
-		/* Optional callback */
-		if (dev->set_mode_resume)
-			return dev->set_mode_resume(dev);
-		else
-			return 0;
-
 	default:
 		return -ENOSYS;
 	}
@@ -184,6 +177,25 @@ void clockevents_shutdown(struct clock_event_device *dev)
 	dev->next_event.tv64 = KTIME_MAX;
 }
 
+/**
+ * clockevents_tick_resume -	Resume the tick device before using it again
+ * @dev:			device to resume
+ */
+int clockevents_tick_resume(struct clock_event_device *dev)
+{
+	int ret = 0;
+
+	if (dev->set_mode)
+		dev->set_mode(CLOCK_EVT_MODE_RESUME, dev);
+	else if (dev->tick_resume)
+		ret = dev->tick_resume(dev);
+
+	if (likely(!ret))
+		dev->mode = CLOCK_EVT_MODE_RESUME;
+
+	return ret;
+}
+
 #ifdef CONFIG_GENERIC_CLOCKEVENTS_MIN_ADJUST
 
 /* Limit min_delta to a jiffie */
@@ -433,7 +445,7 @@ static int clockevents_sanity_check(struct clock_event_device *dev)
 	if (dev->set_mode) {
 		/* We shouldn't be supporting new modes now */
 		WARN_ON(dev->set_mode_periodic || dev->set_mode_oneshot ||
-			dev->set_mode_shutdown || dev->set_mode_resume);
+			dev->set_mode_shutdown || dev->tick_resume);
 		return 0;
 	}