HID: hid-ntrig: init settle and mode check

Adding a wait before the wakeup signal.

As a precautionary measure sanity check the current sensor mode.  If
needed reset it to "dual".

When the device is responding poorly and needs the wakeup call, it was
missing it.  Giving it a chance to settle first improves the chances
that signal gets through.
Signed-off-by: Rafi Rubin <rafi@seas.upenn.edu>
Tested-by: Peter Hutterer <peter.hutterer@who-t.net>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

drivers/hid/hid-ntrig.c

@@ -110,6 +110,36 @@ static int ntrig_version_string(unsigned char *raw, char *buf)
 	return sprintf(buf, "%u.%u.%u.%u.%u", a, b, c, d, e);
 }
 
+static inline int ntrig_get_mode(struct hid_device *hdev)
+{
+	struct hid_report *report = hdev->report_enum[HID_FEATURE_REPORT].
+				    report_id_hash[0x0d];
+
+	if (!report)
+		return -EINVAL;
+
+	usbhid_submit_report(hdev, report, USB_DIR_IN);
+	usbhid_wait_io(hdev);
+	return (int)report->field[0]->value[0];
+}
+
+static inline void ntrig_set_mode(struct hid_device *hdev, const int mode)
+{
+	struct hid_report *report;
+	__u8 mode_commands[4] = { 0xe, 0xf, 0x1b, 0x10 };
+
+	if (mode < 0 || mode > 3)
+		return;
+
+	report = hdev->report_enum[HID_FEATURE_REPORT].
+		 report_id_hash[mode_commands[mode]];
+
+	if (!report)
+		return;
+
+	usbhid_submit_report(hdev, report, USB_DIR_IN);
+}
+
 static void ntrig_report_version(struct hid_device *hdev)
 {
 	int ret;
@@ -905,8 +935,19 @@ static int ntrig_probe(struct hid_device *hdev, const struct hid_device_id *id)
 
 	/* This is needed for devices with more recent firmware versions */
 	report = hdev->report_enum[HID_FEATURE_REPORT].report_id_hash[0x0a];
-	if (report)
-		usbhid_submit_report(hdev, report, USB_DIR_OUT);
+	if (report) {
+		/* Let the device settle to ensure the wakeup message gets
+		 * through */
+		usbhid_wait_io(hdev);
+		usbhid_submit_report(hdev, report, USB_DIR_IN);
+
+		/*
+		 * Sanity check: if the current mode is invalid reset it to
+		 * something reasonable.
+		 */
+		if (ntrig_get_mode(hdev) >= 4)
+			ntrig_set_mode(hdev, 3);
+	}
 
 	ntrig_report_version(hdev);