[driver model] Remove 'power' file in favor of 'power' directory.

- Only present when CONFIG_PM=y.
- Contains 'state' file for controlling power state with new PM 
  infrastructure.

drivers/base/interface.c

@@ -21,75 +21,6 @@ static ssize_t device_read_name(struct device * dev, char * buf)
 
 static DEVICE_ATTR(name,S_IRUGO,device_read_name,NULL);
 
-static ssize_t
-device_read_power(struct device * dev, char * page)
-{
-	return sprintf(page,"%d\n",dev->power_state);
-}
-
-static ssize_t
-device_write_power(struct device * dev, const char * buf, size_t count)
-{
-	char	str_command[20];
-	char	str_level[20];
-	int	num_args;
-	u32	state;
-	u32	int_level;
-	int	error = 0;
-
-	if (!dev->driver)
-		goto done;
-
-	num_args = sscanf(buf,"%10s %10s %u",str_command,str_level,&state);
-
-	error = -EINVAL;
-
-	if (!num_args)
-		goto done;
-
-	if (!strnicmp(str_command,"suspend",7)) {
-		if (num_args != 3)
-			goto done;
-		if (!strnicmp(str_level,"notify",6))
-			int_level = SUSPEND_NOTIFY;
-		else if (!strnicmp(str_level,"save",4))
-			int_level = SUSPEND_SAVE_STATE;
-		else if (!strnicmp(str_level,"disable",7))
-			int_level = SUSPEND_DISABLE;
-		else if (!strnicmp(str_level,"powerdown",8))
-			int_level = SUSPEND_POWER_DOWN;
-		else
-			goto done;
-
-		if (dev->driver->suspend)
-			error = dev->driver->suspend(dev,state,int_level);
-		else
-			error = 0;
-	} else if (!strnicmp(str_command,"resume",6)) {
-		if (num_args != 2)
-			goto done;
-
-		if (!strnicmp(str_level,"poweron",7))
-			int_level = RESUME_POWER_ON;
-		else if (!strnicmp(str_level,"restore",7))
-			int_level = RESUME_RESTORE_STATE;
-		else if (!strnicmp(str_level,"enable",6))
-			int_level = RESUME_ENABLE;
-		else
-			goto done;
-
-		if (dev->driver->resume)
-			error = dev->driver->resume(dev,int_level);
-		else
-			error = 0;
-	}
- done:
-	return error < 0 ? error : count;
-}
-
-static DEVICE_ATTR(power,S_IWUSR | S_IRUGO,
-		   device_read_power,device_write_power);
-
 /**
  *	detach_state - control the default power state for the device.
  *	
@@ -123,7 +54,6 @@ static DEVICE_ATTR(detach_state,0644,detach_show,detach_store);
 
 struct attribute * dev_default_attrs[] = {
 	&dev_attr_name.attr,
-	&dev_attr_power.attr,
 	&dev_attr_detach_state.attr,
 	NULL,
 };

drivers/base/power/sysfs.c

@@ -5,6 +5,25 @@
 #include <linux/device.h>
 #include "power.h"
 
+
+/**
+ *	state - Control current power state of device
+ *
+ *	show() returns the current power state of the device. '0' indicates
+ *	the device is on. Other values (1-3) indicate the device is in a low
+ *	power state. 
+ *
+ *	store() sets the current power state, which is an integer value 
+ *	between 0-3. If the device is on ('0'), and the value written is 
+ *	greater than 0, then the device is placed directly into the low-power
+ *	state (via its driver's ->suspend() method).
+ *	If the device is currently in a low-power state, and the value is 0,
+ *	the device is powered back on (via the ->resume() method).
+ *	If the device is in a low-power state, and a different low-power state
+ *	is requested, the device is first resumed, then suspended into the new
+ *	low-power state.
+ */
+
 static ssize_t state_show(struct device * dev, char * buf)
 {
 	return sprintf(buf,"%u\n",dev->power.power_state);
@@ -26,8 +45,7 @@ static ssize_t state_store(struct device * dev, const char * buf, size_t n)
 	return error ? error : n;
 }
 
-DEVICE_ATTR(state,0644,state_show,state_store);
-
+static DEVICE_ATTR(state,0644,state_show,state_store);
 
 
 static struct attribute * power_attrs[] = {
@@ -35,7 +53,7 @@ static struct attribute * power_attrs[] = {
 	NULL,
 };
 static struct attribute_group pm_attr_group = {
-	.name	= "pm",
+	.name	= "power",
 	.attrs	= power_attrs,
 };