[media] si2157: implement sleep

Implement sleep for power-management.
Signed-off-by: Antti Palosaari <crope@iki.fi>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>

drivers/media/tuners/si2157.c

@@ -89,12 +89,23 @@ static int si2157_init(struct dvb_frontend *fe)
 static int si2157_sleep(struct dvb_frontend *fe)
 {
 	struct si2157 *s = fe->tuner_priv;
+	int ret;
+	struct si2157_cmd cmd;
 
 	dev_dbg(&s->client->dev, "%s:\n", __func__);
 
 	s->active = false;
 
+	memcpy(cmd.args, "\x13", 1);
+	cmd.len = 1;
+	ret = si2157_cmd_execute(s, &cmd);
+	if (ret)
+		goto err;
+
 	return 0;
+err:
+	dev_dbg(&s->client->dev, "%s: failed=%d\n", __func__, ret);
+	return ret;
 }
 
 static int si2157_set_params(struct dvb_frontend *fe)