[power] Improve suspend functions.

- Implement pm_suspend(), which is callable from anywhere in the kernel, 
  and takes one of 

  	PM_SUSPEND_STANDBY
	PM_SUSPEND_MEM
	PM_SUSPEND_DISK

  and enters the appropriate state. 

- Change sysfs file to look for 

  "standby"
  "mem"
  "disk"

  for what state to enter (rather than 'suspend' and 'hibernate' for the 
  latter two). 

- Add pm_sem to block multiple suspend sequences happening at once. 

- Allocate a console and stop processes from common code before entering
  state.

- Add pm_power_down() callback for platform drivers to implement. Will be 
  called to actually enter the low-power state.

1 files changed, 22 insertions, 0 deletions

diff --git a/include/linux/pm.h b/include/linux/pm.h
index e4c795f71cea..a5e4d115d172 100644
--- a/include/linux/pm.h
+++ b/include/linux/pm.h
@@ -186,9 +186,31 @@ static inline void pm_dev_idle(struct pm_dev *dev) {}
 
 #endif /* CONFIG_PM */
 
+
+/*
+ * Callbacks for platform drivers to implement.
+ */
 extern void (*pm_idle)(void);
 extern void (*pm_power_off)(void);
 
+enum {
+	PM_SUSPEND_ON,
+	PM_SUSPEND_STANDBY,
+	PM_SUSPEND_MEM,
+	PM_SUSPEND_DISK,
+	PM_SUSPEND_MAX,
+};
+
+extern int (*pm_power_down)(u32 state);
+
+
+extern int pm_suspend(u32 state);
+
+
+/*
+ * Device power management
+ */
+
 struct device;
 
 struct dev_pm_info {