sh: CMT: Introduce clocksource/clock events suspend/resume routines

Introduce suspend/resume routines for SH CMT clock event devices and
modify the suspend/resume routines for SH CMT clock sources such that
if those devices belong to a PM domain, the generic PM domains
framework will be notified that the given domain may be turned off
(during system suspend) or that it has to be turned on (during system
resume).

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Magnus Damm <damm@opensource.se>

drivers/clocksource/sh_cmt.c

@@ -464,9 +464,20 @@ static void sh_cmt_clocksource_disable(struct clocksource *cs)
 	sh_cmt_stop(cs_to_sh_cmt(cs), FLAG_CLOCKSOURCE);
 }
 
+static void sh_cmt_clocksource_suspend(struct clocksource *cs)
+{
+	struct sh_cmt_priv *p = cs_to_sh_cmt(cs);
+
+	sh_cmt_stop(p, FLAG_CLOCKSOURCE);
+	pm_genpd_syscore_poweroff(&p->pdev->dev);
+}
+
 static void sh_cmt_clocksource_resume(struct clocksource *cs)
 {
-	sh_cmt_start(cs_to_sh_cmt(cs), FLAG_CLOCKSOURCE);
+	struct sh_cmt_priv *p = cs_to_sh_cmt(cs);
+
+	pm_genpd_syscore_poweron(&p->pdev->dev);
+	sh_cmt_start(p, FLAG_CLOCKSOURCE);
 }
 
 static int sh_cmt_register_clocksource(struct sh_cmt_priv *p,
@@ -479,7 +490,7 @@ static int sh_cmt_register_clocksource(struct sh_cmt_priv *p,
 	cs->read = sh_cmt_clocksource_read;
 	cs->enable = sh_cmt_clocksource_enable;
 	cs->disable = sh_cmt_clocksource_disable;
-	cs->suspend = sh_cmt_clocksource_disable;
+	cs->suspend = sh_cmt_clocksource_suspend;
 	cs->resume = sh_cmt_clocksource_resume;
 	cs->mask = CLOCKSOURCE_MASK(sizeof(unsigned long) * 8);
 	cs->flags = CLOCK_SOURCE_IS_CONTINUOUS;
@@ -562,6 +573,16 @@ static int sh_cmt_clock_event_next(unsigned long delta,
 	return 0;
 }
 
+static void sh_cmt_clock_event_suspend(struct clock_event_device *ced)
+{
+	pm_genpd_syscore_poweroff(&ced_to_sh_cmt(ced)->pdev->dev);
+}
+
+static void sh_cmt_clock_event_resume(struct clock_event_device *ced)
+{
+	pm_genpd_syscore_poweron(&ced_to_sh_cmt(ced)->pdev->dev);
+}
+
 static void sh_cmt_register_clockevent(struct sh_cmt_priv *p,
 				       char *name, unsigned long rating)
 {
@@ -576,6 +597,8 @@ static void sh_cmt_register_clockevent(struct sh_cmt_priv *p,
 	ced->cpumask = cpumask_of(0);
 	ced->set_next_event = sh_cmt_clock_event_next;
 	ced->set_mode = sh_cmt_clock_event_mode;
+	ced->suspend = sh_cmt_clock_event_suspend;
+	ced->resume = sh_cmt_clock_event_resume;
 
 	dev_info(&p->pdev->dev, "used for clock events\n");
 	clockevents_register_device(ced);
@@ -690,8 +713,12 @@ static int __devinit sh_cmt_probe(struct platform_device *pdev)
 	struct sh_cmt_priv *p = platform_get_drvdata(pdev);
 	int ret;
 
-	if (!is_early_platform_device(pdev))
-		pm_genpd_dev_always_on(&pdev->dev, true);
+	if (!is_early_platform_device(pdev)) {
+		struct sh_timer_config *cfg = pdev->dev.platform_data;
+
+		if (cfg->clocksource_rating || cfg->clockevent_rating)
+			pm_genpd_dev_always_on(&pdev->dev, true);
+	}
 
 	if (p) {
 		dev_info(&pdev->dev, "kept as earlytimer\n");