ACPI: thinkpad-acpi: do not use named sysfs groups

The initial version of the thinkpad-acpi sysfs interface (not yet released
in any stable mainline kernel) made liberal use of named sysfs groups, in
order to get the attributes more organized.

This proved to be a really bad design decision.  Maybe if attribute groups
were as flexible as a real directory, and if binary attributes were not
second-class citizens, the idea of subdirs and named groups would not have
been so bad.

This patch makes all the thinkpad-acpi sysfs groups anonymous (thus
removing the subdirs), adds the former group names as a prefix (so that
hotkey/enable becomes hotkey_enable for example), and updates the
documentation.

These changes will make the thinkpad-acpi sysfs ABI a lot easier to
maintain.

Signed-off-by: Henrique de Moraes Holschuh <hmh@hmh.eng.br>
Signed-off-by: Len Brown <len.brown@intel.com>
diff --git a/Documentation/thinkpad-acpi.txt b/Documentation/thinkpad-acpi.txt
index 2d48033..9e6b94f 100644
--- a/Documentation/thinkpad-acpi.txt
+++ b/Documentation/thinkpad-acpi.txt
@@ -138,7 +138,7 @@
 --------
 
 procfs: /proc/acpi/ibm/hotkey
-sysfs device attribute: hotkey/*
+sysfs device attribute: hotkey_*
 
 Without this driver, only the Fn-F4 key (sleep button) generates an
 ACPI event. With the driver loaded, the hotkey feature enabled and the
@@ -196,10 +196,7 @@
 
 sysfs notes:
 
-	The hot keys attributes are in a hotkey/ subdirectory off the
-	thinkpad device.
-
-	bios_enabled:
+	hotkey_bios_enabled:
 		Returns the status of the hot keys feature when
 		thinkpad-acpi was loaded.  Upon module unload, the hot
 		key feature status will be restored to this value.
@@ -207,19 +204,19 @@
 		0: hot keys were disabled
 		1: hot keys were enabled
 
-	bios_mask:
+	hotkey_bios_mask:
 		Returns the hot keys mask when thinkpad-acpi was loaded.
 		Upon module unload, the hot keys mask will be restored
 		to this value.
 
-	enable:
+	hotkey_enable:
 		Enables/disables the hot keys feature, and reports
 		current status of the hot keys feature.
 
 		0: disables the hot keys feature / feature disabled
 		1: enables the hot keys feature / feature enabled
 
-	mask:
+	hotkey_mask:
 		bit mask to enable ACPI event generation for each hot
 		key (see above).  Returns the current status of the hot
 		keys mask, and allows one to modify it.
@@ -229,7 +226,7 @@
 ---------
 
 procfs: /proc/acpi/ibm/bluetooth
-sysfs device attribute: bluetooth/enable
+sysfs device attribute: bluetooth_enable
 
 This feature shows the presence and current state of a ThinkPad
 Bluetooth device in the internal ThinkPad CDC slot.
@@ -244,7 +241,7 @@
 Sysfs notes:
 
 	If the Bluetooth CDC card is installed, it can be enabled /
-	disabled through the "bluetooth/enable" thinkpad-acpi device
+	disabled through the "bluetooth_enable" thinkpad-acpi device
 	attribute, and its current status can also be queried.
 
 	enable:
@@ -252,7 +249,7 @@
 		1: enables Bluetooth / Bluetooth is enabled.
 
 	Note: this interface will be probably be superseeded by the
-	generic rfkill class.
+	generic rfkill class, so it is NOT to be considered stable yet.
 
 Video output control -- /proc/acpi/ibm/video
 --------------------------------------------
@@ -898,7 +895,7 @@
 -----------------
 
 procfs: /proc/acpi/ibm/wan
-sysfs device attribute: wwan/enable
+sysfs device attribute: wwan_enable
 
 This feature is marked EXPERIMENTAL because the implementation
 directly accesses hardware registers and may not work as expected. USE
@@ -921,7 +918,7 @@
 Sysfs notes:
 
 	If the W-WAN card is installed, it can be enabled /
-	disabled through the "wwan/enable" thinkpad-acpi device
+	disabled through the "wwan_enable" thinkpad-acpi device
 	attribute, and its current status can also be queried.
 
 	enable:
@@ -929,7 +926,7 @@
 		1: enables WWAN card / WWAN card is enabled.
 
 	Note: this interface will be probably be superseeded by the
-	generic rfkill class.
+	generic rfkill class, so it is NOT to be considered stable yet.
 
 Multiple Commands, Module Parameters
 ------------------------------------