Re: [linux-pm] Re: [PATCH, RFC] [1/3] Generic in-kernel AC status

[Matthew Garrett <mjg59@srcf.ucam.org>]

On Wed, Feb 08, 2006 at 09:16:49AM -0800, Greg KH wrote:

> kerneldoc will not work with this.  It needs to be a one line, short,
> description.  Put the full description below the function paramaters, it
> can be as many lines as you want there.

Ok, how's this one?

Signed-Off-By: Matthew Garrett <mjg59@srcf.ucam.org>

diff --git a/include/linux/pm.h b/include/linux/pm.h
index 5be87ba..59ece0f 100644
--- a/include/linux/pm.h
+++ b/include/linux/pm.h
@@ -129,6 +129,8 @@ struct pm_ops {
 
 extern void pm_set_ops(struct pm_ops *);
 extern struct pm_ops *pm_ops;
+extern void pm_set_ac_status(int (*ac_status_function)(void));
+extern int pm_get_ac_status(void);
 extern int pm_suspend(suspend_state_t state);
 
 
diff --git a/kernel/power/main.c b/kernel/power/main.c
index 46110d5..31745fb 100644
--- a/kernel/power/main.c
+++ b/kernel/power/main.c
@@ -15,7 +15,7 @@
 #include <linux/errno.h>
 #include <linux/init.h>
 #include <linux/pm.h>
-
+#include <linux/module.h>
 
 #include "power.h"
 
@@ -25,6 +25,7 @@
 DECLARE_MUTEX(pm_sem);
 
 struct pm_ops *pm_ops = NULL;
+int (*get_ac_status)(void);
 suspend_disk_method_t pm_disk_mode = PM_DISK_SHUTDOWN;
 
 /**
@@ -39,6 +40,41 @@ void pm_set_ops(struct pm_ops * ops)
 	up(&pm_sem);
 }
 
+/**
+ *	pm_set_ac_status - Set the ac status callback.
+ *	@ops:	Pointer to function
+ *
+ *      Provide a callback that returns true if the system is currently on
+ *      AC power. This should be called by power management subsystems.
+ */
+
+void pm_set_ac_status(int (*ac_status_function)(void))
+{
+	down(&pm_sem);
+	get_ac_status = ac_status_function;
+	up(&pm_sem);
+}
+EXPORT_SYMBOL_GPL(pm_set_ac_status);
+
+/**
+ *	pm_get_ac_status - return true if the system is on AC
+ *
+ *      Returns true if the system has a registered callback for determining 
+ *      AC state and is currently on AC power, false otherwise.
+ */
+
+int pm_get_ac_status(void)
+{
+	int status=0;
+
+	down (&pm_sem);
+	if (get_ac_status)
+		status = get_ac_status();
+	up (&pm_sem);
+
+	return status;
+}
+EXPORT_SYMBOL_GPL(pm_get_ac_status);
 
 /**
  *	suspend_prepare - Do prep work before entering low-power state.

-- 
Matthew Garrett | mjg59@srcf.ucam.org