HID: usbhid: defer LED setting to a workqueue

Defer LED setting action to a workqueue.
This is more likely to send all LED change events in a single URB.

Signed-off-by: Daniel Kurtz <djkurtz@chromium.org>
Acked-by: Oliver Neukum <oneukum@suse.de>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
diff --git a/drivers/hid/hid-input.c b/drivers/hid/hid-input.c
index b9b8c75..c6ee632 100644
--- a/drivers/hid/hid-input.c
+++ b/drivers/hid/hid-input.c
@@ -976,6 +976,48 @@
 }
 EXPORT_SYMBOL_GPL(hidinput_find_field);
 
+struct hid_field *hidinput_get_led_field(struct hid_device *hid)
+{
+	struct hid_report *report;
+	struct hid_field *field;
+	int i, j;
+
+	list_for_each_entry(report,
+			    &hid->report_enum[HID_OUTPUT_REPORT].report_list,
+			    list) {
+		for (i = 0; i < report->maxfield; i++) {
+			field = report->field[i];
+			for (j = 0; j < field->maxusage; j++)
+				if (field->usage[j].type == EV_LED)
+					return field;
+		}
+	}
+	return NULL;
+}
+EXPORT_SYMBOL_GPL(hidinput_get_led_field);
+
+unsigned int hidinput_count_leds(struct hid_device *hid)
+{
+	struct hid_report *report;
+	struct hid_field *field;
+	int i, j;
+	unsigned int count = 0;
+
+	list_for_each_entry(report,
+			    &hid->report_enum[HID_OUTPUT_REPORT].report_list,
+			    list) {
+		for (i = 0; i < report->maxfield; i++) {
+			field = report->field[i];
+			for (j = 0; j < field->maxusage; j++)
+				if (field->usage[j].type == EV_LED &&
+				    field->value[j])
+					count += 1;
+		}
+	}
+	return count;
+}
+EXPORT_SYMBOL_GPL(hidinput_count_leds);
+
 static int hidinput_open(struct input_dev *dev)
 {
 	struct hid_device *hid = input_get_drvdata(dev);