asus-wmi: add CWAP support and clarify the meaning of WAPF bits

ref: http://dev.iksaif.net/projects/3/wiki/Asus-laptop_WAPF

Signed-off-by: Corentin Chary <corentin.chary@gmail.com>
Signed-off-by: Matthew Garrett <mjg@redhat.com>
diff --git a/drivers/platform/x86/asus-wmi.c b/drivers/platform/x86/asus-wmi.c
index 3b9fb91..8787dfa 100644
--- a/drivers/platform/x86/asus-wmi.c
+++ b/drivers/platform/x86/asus-wmi.c
@@ -1413,6 +1413,12 @@
 		return -ENODEV;
 	}
 
+	/* CWAP allow to define the behavior of the Fn+F2 key,
+	 * this method doesn't seems to be present on Eee PCs */
+	if (asus->driver->wapf >= 0)
+		asus_wmi_set_devstate(ASUS_WMI_DEVID_CWAP,
+				      asus->driver->wapf, NULL);
+
 	return asus_wmi_sysfs_init(asus->platform_device);
 }