[PATCH 05/05] PM: Runtime PM v13 - platform device bus support

[Magnus Damm <magnus.damm@gmail.com>]

From: Magnus Damm <damm@igel.co.jp>

This patch adds default Runtime PM callbacks to the dev_pm_ops
belonging to the platform bus. The callbacks are weak symbols
that architecture specific code may override. Also, call
pm_runtime_enable() for the platform bus struct device.

Allows Runtime PM even though CONFIG_PM_SLEEP=n.

Signed-off-by: Magnus Damm <damm@igel.co.jp>
---

 Please let me know if this platform device core change is acceptable.

 Changes:
 - Based on "Driver Core: Runtime PM callbacks for the Platform Bus V2"
 - Reworked to handle CONFIG_PM_SLEEP=n case

 drivers/base/platform.c |   48 ++++++++++++++++++++++++++++++++++++++---------
 1 file changed, 39 insertions(+), 9 deletions(-)

--- 0001/drivers/base/platform.c
+++ work/drivers/base/platform.c	2009-08-07 15:25:14.000000000 +0900
@@ -17,6 +17,7 @@
 #include <linux/bootmem.h>
 #include <linux/err.h>
 #include <linux/slab.h>
+#include <linux/pm_runtime.h>
 
 #include "base.h"
 
@@ -683,6 +684,13 @@ static void platform_pm_complete(struct 
 		drv->pm->complete(dev);
 }
 
+#else /* !CONFIG_PM_SLEEP */
+
+#define platform_pm_prepare		NULL
+#define platform_pm_complete		NULL
+
+#endif /* !CONFIG_PM_SLEEP */
+
 #ifdef CONFIG_SUSPEND
 
 static int platform_pm_suspend(struct device *dev)
@@ -925,6 +933,30 @@ static int platform_pm_restore_noirq(str
 
 #endif /* !CONFIG_HIBERNATION */
 
+#ifdef CONFIG_PM_RUNTIME
+
+int __weak platform_pm_runtime_suspend(struct device *dev)
+{
+	return -ENOSYS;
+};
+
+int __weak platform_pm_runtime_resume(struct device *dev)
+{
+	return -ENOSYS;
+};
+
+void __weak platform_pm_runtime_idle(struct device *dev)
+{
+};
+
+#else /* !CONFIG_PM_RUNTIME */
+
+#define platform_pm_runtime_suspend NULL
+#define platform_pm_runtime_resume NULL
+#define platform_pm_runtime_idle NULL
+
+#endif /* !CONFIG_PM_RUNTIME */
+
 static struct dev_pm_ops platform_dev_pm_ops = {
 	.prepare = platform_pm_prepare,
 	.complete = platform_pm_complete,
@@ -940,22 +972,17 @@ static struct dev_pm_ops platform_dev_pm
 	.thaw_noirq = platform_pm_thaw_noirq,
 	.poweroff_noirq = platform_pm_poweroff_noirq,
 	.restore_noirq = platform_pm_restore_noirq,
+	.runtime_suspend = platform_pm_runtime_suspend,
+	.runtime_resume = platform_pm_runtime_resume,
+	.runtime_idle = platform_pm_runtime_idle,
 };
 
-#define PLATFORM_PM_OPS_PTR	(&platform_dev_pm_ops)
-
-#else /* !CONFIG_PM_SLEEP */
-
-#define PLATFORM_PM_OPS_PTR	NULL
-
-#endif /* !CONFIG_PM_SLEEP */
-
 struct bus_type platform_bus_type = {
 	.name		= "platform",
 	.dev_attrs	= platform_dev_attrs,
 	.match		= platform_match,
 	.uevent		= platform_uevent,
-	.pm		= PLATFORM_PM_OPS_PTR,
+	.pm		= &platform_dev_pm_ops,
 };
 EXPORT_SYMBOL_GPL(platform_bus_type);
 
@@ -968,6 +995,9 @@ int __init platform_bus_init(void)
 	error = device_register(&platform_bus);
 	if (error)
 		return error;
+
+	pm_runtime_enable(&platform_bus);
+
 	error =  bus_register(&platform_bus_type);
 	if (error)
 		device_unregister(&platform_bus);