acer-wmi: Detect communication hot key number

Currently we set a fixed hot key number to 0x01 for communction button,
but, actually, the key number is different on each acer laptop and it was
reported by SMBIOS.

So, add this patch to get the communication hot key number from Acer
OEM-specific SMBIOS Type AA.

Tested on Acer TravelMate 4750

Cc: Carlos Corbacho <carlos@strangeworlds.co.uk>
Cc: Matthew Garrett <mjg@redhat.com>
Cc: Dmitry Torokhov <dtor@mail.ru>
Cc: Corentin Chary <corentincj@iksaif.net>
Cc: Thomas Renninger <trenn@suse.de>
Signed-off-by: Lee, Chun-Yi <jlee@suse.com>
Signed-off-by: Matthew Garrett <mjg@redhat.com>

drivers/platform/x86/acer-wmi.c

@@ -177,6 +177,11 @@ struct hotkey_function_type_aa {
 	u8 length;
 	u16 handle;
 	u16 commun_func_bitmap;
+	u16 application_func_bitmap;
+	u16 media_func_bitmap;
+	u16 display_func_bitmap;
+	u16 others_func_bitmap;
+	u8 commun_fn_key_number;
 } __attribute__((packed));
 
 /*
@@ -213,6 +218,7 @@ static int force_series;
 static bool ec_raw_mode;
 static bool has_type_aa;
 static u16 commun_func_bitmap;
+static u8 commun_fn_key_number;
 
 module_param(mailled, int, 0444);
 module_param(brightness, int, 0444);
@@ -918,7 +924,7 @@ static acpi_status wmid3_get_device_status(u32 *value, u16 device)
 	union acpi_object *obj;
 	struct wmid3_gds_input_param params = {
 		.function_num = 0x1,
-		.hotkey_number = 0x01,
+		.hotkey_number = commun_fn_key_number,
 		.devices = device,
 	};
 	struct acpi_buffer input = {
@@ -987,7 +993,7 @@ static acpi_status wmid3_set_device_status(u32 value, u16 device)
 	u16 devices;
 	struct wmid3_gds_input_param params = {
 		.function_num = 0x1,
-		.hotkey_number = 0x01,
+		.hotkey_number = commun_fn_key_number,
 		.devices = commun_func_bitmap,
 	};
 	struct acpi_buffer input = {
@@ -1027,7 +1033,7 @@ static acpi_status wmid3_set_device_status(u32 value, u16 device)
 
 	devices = return_value.devices;
 	params.function_num = 0x2;
-	params.hotkey_number = 0x01;
+	params.hotkey_number = commun_fn_key_number;
 	params.devices = (value) ? (devices | device) : (devices & ~device);
 
 	status = wmi_evaluate_method(WMID_GUID3, 0, 0x1, &input, &output2);
@@ -1100,6 +1106,8 @@ static void type_aa_dmi_decode(const struct dmi_header *header, void *dummy)
 		interface->capability |= ACER_CAP_THREEG;
 	if (type_aa->commun_func_bitmap & ACER_WMID3_GDS_BLUETOOTH)
 		interface->capability |= ACER_CAP_BLUETOOTH;
+
+	commun_fn_key_number = type_aa->commun_fn_key_number;
 }
 
 static acpi_status WMID_set_capabilities(void)