[media] it913x: init tuner on attach

That register is needed to program very first in order to operate
correctly.

[crope@iki.fi: returned sequence back, removed sleep, moved reg
write earlier to prevent populating tuner ops in case of failure]

Cc: <stable@vger.kernel.org> # v3.15+
Signed-off-by: Bimow Chen <Bimow.Chen@ite.com.tw>
Signed-off-by: Antti Palosaari <crope@iki.fi>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>

drivers/media/tuners/tuner_it913x.c

@@ -396,6 +396,7 @@ struct dvb_frontend *it913x_attach(struct dvb_frontend *fe,
 		struct i2c_adapter *i2c_adap, u8 i2c_addr, u8 config)
 {
 	struct it913x_state *state = NULL;
+	int ret;
 
 	/* allocate memory for the internal state */
 	state = kzalloc(sizeof(struct it913x_state), GFP_KERNEL);
@@ -425,6 +426,11 @@ struct dvb_frontend *it913x_attach(struct dvb_frontend *fe,
 	state->tuner_type = config;
 	state->firmware_ver = 1;
 
+	/* tuner RF initial */
+	ret = it913x_wr_reg(state, PRO_DMOD, 0xec4c, 0x68);
+	if (ret < 0)
+		goto error;
+
 	fe->tuner_priv = state;
 	memcpy(&fe->ops.tuner_ops, &it913x_tuner_ops,
 			sizeof(struct dvb_tuner_ops));