sony-laptop: enumerate rfkill devices using SN06

SN06 makes sure we get back a longer buffer which seems to be necessary
going forward as the SNC devices describes more and more devices (or
features more precisely). Moreover SN06 should be called with only the
descriptor offset to make sure we hit the rfkill controlling function
(F124 or F135) with a 0 argument to get a full list of features.
Signed-off-by: Mattia Dongili <malattia@linux.it>
Tested-by: Miguel Rodríguez Pérez <miguelrp@gmail.com>
Signed-off-by: Len Brown <len.brown@intel.com>

drivers/platform/x86/sony-laptop.c

@@ -1156,35 +1156,73 @@ static void sony_nc_rfkill_update()
 	}
 }
 
-static int sony_nc_rfkill_setup(struct acpi_device *device)
+static void sony_nc_rfkill_setup(struct acpi_device *device)
 {
-	int result, ret;
+	int offset;
+	u8 dev_code, i;
+	acpi_status status;
+	struct acpi_object_list params;
+	union acpi_object in_obj;
+	union acpi_object *device_enum;
+	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 
-	if (sony_find_snc_handle(0x124) == -1) {
-		if (sony_find_snc_handle(0x135) == -1)
-			return -1;
+	offset = sony_find_snc_handle(0x124);
+	if (offset == -1) {
+		offset = sony_find_snc_handle(0x135);
+		if (offset == -1)
+			return;
 		else
 			sony_rfkill_handle = 0x135;
 	} else
 		sony_rfkill_handle = 0x124;
+	dprintk("Found rkfill handle: 0x%.4x\n", sony_rfkill_handle);
 
-	ret = sony_call_snc_handle(sony_rfkill_handle, 0xb00, &result);
-	if (ret) {
-		printk(KERN_INFO DRV_PFX
-		       "Unable to enumerate rfkill devices: %x\n", ret);
-		return ret;
+	/* need to read the whole buffer returned by the acpi call to SN06
+	 * here otherwise we may miss some features
+	 */
+	params.count = 1;
+	params.pointer = &in_obj;
+	in_obj.type = ACPI_TYPE_INTEGER;
+	in_obj.integer.value = offset;
+	status = acpi_evaluate_object(sony_nc_acpi_handle, "SN06", &params,
+			&buffer);
+	if (ACPI_FAILURE(status)) {
+		dprintk("Radio device enumeration failed\n");
+		return;
+	}
+
+	device_enum = (union acpi_object *) buffer.pointer;
+	if (!device_enum || device_enum->type != ACPI_TYPE_BUFFER) {
+		printk(KERN_ERR "Invalid SN06 return object 0x%.2x\n",
+				device_enum->type);
+		goto out_no_enum;
 	}
 
-	if (result & 0x1)
+	/* the buffer is filled with magic numbers describing the devices
+	 * available, 0xff terminates the enumeration
+	 */
+	while ((dev_code = *(device_enum->buffer.pointer + i)) != 0xff &&
+			i < device_enum->buffer.length) {
+		i++;
+		dprintk("Radio devices, looking at 0x%.2x\n", dev_code);
+
+		if (dev_code == 0 && !sony_rfkill_devices[SONY_WIFI])
 			sony_nc_setup_rfkill(device, SONY_WIFI);
-	if (result & 0x2)
+
+		if (dev_code == 0x10 && !sony_rfkill_devices[SONY_BLUETOOTH])
 			sony_nc_setup_rfkill(device, SONY_BLUETOOTH);
-	if (result & 0x1c)
+
+		if ((0xf0 & dev_code) == 0x20 &&
+				!sony_rfkill_devices[SONY_WWAN])
 			sony_nc_setup_rfkill(device, SONY_WWAN);
-	if (result & 0x20)
+
+		if (dev_code == 0x30 && !sony_rfkill_devices[SONY_WIMAX])
 			sony_nc_setup_rfkill(device, SONY_WIMAX);
+	}
 
-	return 0;
+out_no_enum:
+	kfree(buffer.pointer);
+	return;
 }
 
 static int sony_nc_add(struct acpi_device *device)