[ACPI] generic Hot Key support

See Documentation/acpi-hotkey.txt

Use cmdline "acpi_specific_hotkey" to enable
legacy platform specific drivers.

http://bugzilla.kernel.org/show_bug.cgi?id=3887

Signed-off-by: Luming Yu <luming.yu@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>

1 files changed, 35 insertions, 0 deletions

diff --git a/Documentation/acpi-hotkey.txt b/Documentation/acpi-hotkey.txt
new file mode 100644
index 000000000000..4c115a7bb826
--- /dev/null
+++ b/Documentation/acpi-hotkey.txt
@@ -0,0 +1,35 @@
+driver/acpi/hotkey.c implement:
+1. /proc/acpi/hotkey/event_config 
+(event based hotkey or event config interface):
+a. add a  event based hotkey(event) : 
+echo "0:bus::action:method:num:num" > event_config
+
+b. delete a event based hotkey(event): 
+echo "1:::::num:num" > event_config
+
+c.  modify a event based hotkey(event):    
+echo "2:bus::action:method:num:num" > event_config
+
+2. /proc/acpi/hotkey/poll_config 
+(polling based hotkey or event config interface):
+a.add a polling based hotkey(event) : 	
+echo "0:bus:method:action:method:num" > poll_config
+this adding command will create a proc file 
+/proc/acpi/hotkey/method, which is used to get 
+result of polling.
+
+b.delete a polling based hotkey(event): 	
+echo "1:::::num" > event_config
+
+c.modify a polling based hotkey(event):    
+echo "2:bus:method:action:method:num" > poll_config
+
+3./proc/acpi/hotkey/action 
+(interface to call aml method associated with a 
+specific hotkey(event))
+echo "event_num:event_type:event_argument" > 
+	/proc/acpi/hotkey/action.
+The result of the execution of this aml method is 
+attached to /proc/acpi/hotkey/poll_method, which is dnyamically
+created.  Please use command "cat /proc/acpi/hotkey/polling_method" 
+to retrieve it.