HID: Kysona: Add periodic online check

This patch adds a periodic online check at the same interval the battery
status gets requested.
With this change the driver can detect when the mouse is turned off while
the dongle is still plugged in.

Tested with a Kysona M600 V-HUB Special Edition.

Signed-off-by: Lode Willems <me@lodewillems.com>
Signed-off-by: Jiri Kosina <jkosina@suse.com>

Author: Lode Willems

drivers/hid/hid-kysona.c

@@ -14,6 +14,7 @@
 
 #define BATTERY_TIMEOUT_MS 5000
 
+#define ONLINE_REPORT_ID 3
 #define BATTERY_REPORT_ID 4
 
 struct kysona_drvdata {
@@ -80,11 +81,46 @@ static int kysona_battery_get_property(struct power_supply *psy,
 	return ret;
 }
 
+static const char kysona_online_request[] = {
+	0x08, ONLINE_REPORT_ID, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x4a
+};
+
 static const char kysona_battery_request[] = {
 	0x08, BATTERY_REPORT_ID, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
 	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x49
 };
 
+static int kysona_m600_fetch_online(struct hid_device *hdev)
+{
+	u8 *write_buf;
+	int ret;
+
+	/* Request online information */
+	write_buf = kmemdup(kysona_online_request, sizeof(kysona_online_request), GFP_KERNEL);
+	if (!write_buf)
+		return -ENOMEM;
+
+	ret = hid_hw_raw_request(hdev, kysona_online_request[0],
+				 write_buf, sizeof(kysona_online_request),
+				 HID_OUTPUT_REPORT, HID_REQ_SET_REPORT);
+	if (ret < (int)sizeof(kysona_online_request)) {
+		hid_err(hdev, "hid_hw_raw_request() failed with %d\n", ret);
+		ret = -ENODATA;
+	}
+	kfree(write_buf);
+	return ret;
+}
+
+static void kysona_fetch_online(struct hid_device *hdev)
+{
+	int ret = kysona_m600_fetch_online(hdev);
+
+	if (ret < 0)
+		hid_dbg(hdev,
+			"Online query failed (err: %d)\n", ret);
+}
+
 static int kysona_m600_fetch_battery(struct hid_device *hdev)
 {
 	u8 *write_buf;
@@ -121,6 +157,7 @@ static void kysona_battery_timer_tick(struct work_struct *work)
 		struct kysona_drvdata, battery_work.work);
 	struct hid_device *hdev = drv_data->hdev;
 
+	kysona_fetch_online(hdev);
 	kysona_fetch_battery(hdev);
 	schedule_delayed_work(&drv_data->battery_work,
 			      msecs_to_jiffies(BATTERY_TIMEOUT_MS));
@@ -160,6 +197,7 @@ static int kysona_battery_probe(struct hid_device *hdev)
 	power_supply_powers(drv_data->battery, &hdev->dev);
 
 	INIT_DELAYED_WORK(&drv_data->battery_work, kysona_battery_timer_tick);
+	kysona_fetch_online(hdev);
 	kysona_fetch_battery(hdev);
 	schedule_delayed_work(&drv_data->battery_work,
 			      msecs_to_jiffies(BATTERY_TIMEOUT_MS));
@@ -206,12 +244,16 @@ static int kysona_raw_event(struct hid_device *hdev,
 {
 	struct kysona_drvdata *drv_data = hid_get_drvdata(hdev);
 
-	if (drv_data->battery && size == sizeof(kysona_battery_request) &&
+	if (size == sizeof(kysona_online_request) &&
+	    data[0] == 8 && data[1] == ONLINE_REPORT_ID) {
+		drv_data->online = data[6];
+	}
+
+	if (size == sizeof(kysona_battery_request) &&
 	    data[0] == 8 && data[1] == BATTERY_REPORT_ID) {
 		drv_data->battery_capacity = data[6];
 		drv_data->battery_charging = data[7];
 		drv_data->battery_voltage = (data[8] << 8) | data[9];
-		drv_data->online = true;
 	}
 
 	return 0;