staging: nvec: make touchpad init synchronous

Currently, we are constantly sending commands to the EC without waiting for them to be
executed. For the touchpad initialization this only worked because we were waiting 200 µs
between each submitted command byte, so the EC had enough time to execute. In the furture
we like to avoid this delay, so we need to wait for each command to be executed first.
Do this by switching from asynchronous to synchronous command transmission.
Signed-off-by: Marc Dietrich <marvin24@gmx.de>
Link: https://lore.kernel.org/r/20240406123123.37148-4-marvin24@gmx.deSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/nvec/nvec_ps2.c

@@ -60,16 +60,6 @@ static void ps2_stopstreaming(struct serio *ser_dev)
 	nvec_write_async(ps2_dev.nvec, buf, sizeof(buf));
 }
 
-static int ps2_sendcommand(struct serio *ser_dev, unsigned char cmd)
-{
-	unsigned char buf[] = { NVEC_PS2, SEND_COMMAND, ENABLE_MOUSE, 1 };
-
-	buf[2] = cmd & 0xff;
-
-	dev_dbg(&ser_dev->dev, "Sending ps2 cmd %02x\n", cmd);
-	return nvec_write_async(ps2_dev.nvec, buf, sizeof(buf));
-}
-
 static int nvec_ps2_notifier(struct notifier_block *nb,
 			     unsigned long event_type, void *data)
 {
@@ -98,6 +88,27 @@ static int nvec_ps2_notifier(struct notifier_block *nb,
 	return NOTIFY_DONE;
 }
 
+static int ps2_sendcommand(struct serio *ser_dev, unsigned char cmd)
+{
+	unsigned char buf[] = { NVEC_PS2, SEND_COMMAND, ENABLE_MOUSE, 1 };
+	struct nvec_msg *msg;
+	int ret;
+
+	buf[2] = cmd & 0xff;
+
+	dev_dbg(&ser_dev->dev, "Sending ps2 cmd %02x\n", cmd);
+
+	ret = nvec_write_sync(ps2_dev.nvec, buf, sizeof(buf), &msg);
+	if (ret < 0)
+		return ret;
+
+	nvec_ps2_notifier(NULL, NVEC_PS2, msg->data);
+
+	nvec_msg_free(ps2_dev.nvec, msg);
+
+	return 0;
+}
+
 static int nvec_mouse_probe(struct platform_device *pdev)
 {
 	struct nvec_chip *nvec = dev_get_drvdata(pdev->dev.parent);