[PATCH 14/15] sh: MTU2: Basic runtime PM support

From: Rafael J. Wysocki
Date: Sun Aug 05 2012 - 19:49:56 EST



Modify the SH MTU2 clock event device driver to support runtime PM at
a basic level (i.e. device clocks can be disabled and enabled, but
domain power must be on, because the device has to be marked as
"irq safe").

Signed-off-by: Rafael J. Wysocki <rjw@xxxxxxx>
---
drivers/clocksource/sh_mtu2.c | 28 ++++++++++++++++++++++------
1 file changed, 22 insertions(+), 6 deletions(-)

Index: linux/drivers/clocksource/sh_mtu2.c
===================================================================
--- linux.orig/drivers/clocksource/sh_mtu2.c
+++ linux/drivers/clocksource/sh_mtu2.c
@@ -32,6 +32,7 @@
#include <linux/slab.h>
#include <linux/module.h>
#include <linux/pm_domain.h>
+#include <linux/pm_runtime.h>

struct sh_mtu2_priv {
void __iomem *mapbase;
@@ -123,6 +124,9 @@ static int sh_mtu2_enable(struct sh_mtu2
{
int ret;

+ pm_runtime_get_sync(&p->pdev->dev);
+ dev_pm_syscore_device(&p->pdev->dev, true);
+
/* enable clock */
ret = clk_enable(p->clk);
if (ret) {
@@ -157,6 +161,9 @@ static void sh_mtu2_disable(struct sh_mt

/* stop clock */
clk_disable(p->clk);
+
+ dev_pm_syscore_device(&p->pdev->dev, false);
+ pm_runtime_put(&p->pdev->dev);
}

static irqreturn_t sh_mtu2_interrupt(int irq, void *dev_id)
@@ -320,15 +327,13 @@ static int __devinit sh_mtu2_probe(struc
int ret;

if (!is_early_platform_device(pdev)) {
- struct sh_timer_config *cfg = pdev->dev.platform_data;
-
- if (cfg->clockevent_rating)
- dev_pm_syscore_device(&pdev->dev, true);
+ pm_runtime_set_active(&pdev->dev);
+ pm_runtime_enable(&pdev->dev);
}

if (p) {
dev_info(&pdev->dev, "kept as earlytimer\n");
- return 0;
+ goto out;
}

p = kmalloc(sizeof(*p), GFP_KERNEL);
@@ -341,8 +346,19 @@ static int __devinit sh_mtu2_probe(struc
if (ret) {
kfree(p);
platform_set_drvdata(pdev, NULL);
+ pm_runtime_idle(&pdev->dev);
+ return ret;
}
- return ret;
+ if (is_early_platform_device(pdev))
+ return 0;
+
+ out:
+ if (cfg->clockevent_rating)
+ pm_runtime_irq_safe(&pdev->dev);
+ else
+ pm_runtime_idle(&pdev->dev);
+
+ return 0;
}

static int __devexit sh_mtu2_remove(struct platform_device *pdev)

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