V4L/DVB (6138): tea5761: add get_rf_strength and improve status reading efficiency

Signed-off-by: Michael Krufky <mkrufky@linuxtv.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>

drivers/media/video/tea5761.c

@@ -177,49 +177,66 @@ static int set_radio_freq(struct dvb_frontend *fe,
 	return 0;
 }
 
-static int tea5761_signal(struct dvb_frontend *fe)
+static int tea5761_read_status(struct dvb_frontend *fe, char *buffer)
 {
-	unsigned char buffer[16];
-	int rc;
 	struct tea5761_priv *priv = fe->tuner_priv;
+	int rc;
 
-	memset(buffer, 0, sizeof(buffer));
-	if (16 != (rc = tuner_i2c_xfer_recv(&priv->i2c_props, buffer, 16)))
-		tuner_warn("i2c i/o error: rc == %d (should be 5)\n", rc);
+	memset(buffer, 0, 16);
+	if (16 != (rc = tuner_i2c_xfer_recv(&priv->i2c_props, buffer, 16))) {
+		tuner_warn("i2c i/o error: rc == %d (should be 16)\n", rc);
+		return -EREMOTEIO;
+	}
 
-	return ((buffer[9] & TEA5761_TUNCHECK_LEV_MASK) << (13 - 4));
+	return 0;
 }
 
-static int tea5761_stereo(struct dvb_frontend *fe)
+static inline int tea5761_signal(struct dvb_frontend *fe, const char *buffer)
 {
-	unsigned char buffer[16];
-	int rc;
 	struct tea5761_priv *priv = fe->tuner_priv;
 
-	memset(buffer, 0, sizeof(buffer));
-	if (16 != (rc = tuner_i2c_xfer_recv(&priv->i2c_props, buffer, 16)))
-		tuner_warn("i2c i/o error: rc == %d (should be 5)\n", rc);
+	int signal = ((buffer[9] & TEA5761_TUNCHECK_LEV_MASK) << (13 - 4));
+
+	tuner_dbg("Signal strength: %d\n", signal);
 
-	rc = buffer[9] & TEA5761_TUNCHECK_STEREO;
+	return signal;
+}
 
-	tuner_dbg("TEA5761 radio ST GET = %02x\n", rc);
+static inline int tea5761_stereo(struct dvb_frontend *fe, const char *buffer)
+{
+	struct tea5761_priv *priv = fe->tuner_priv;
 
-	return (rc ? V4L2_TUNER_SUB_STEREO : 0);
+	int stereo = buffer[9] & TEA5761_TUNCHECK_STEREO;
+
+	tuner_dbg("Radio ST GET = %02x\n", stereo);
+
+	return (stereo ? V4L2_TUNER_SUB_STEREO : 0);
 }
 
 static int tea5761_get_status(struct dvb_frontend *fe, u32 *status)
 {
-	struct tea5761_priv *priv = fe->tuner_priv;
-	int signal = tea5761_signal(fe);
+	unsigned char buffer[16];
 
 	*status = 0;
 
-	if (signal)
+	if (0 == tea5761_read_status(fe, buffer)) {
+		if (tea5761_signal(fe, buffer))
 			*status = TUNER_STATUS_LOCKED;
-	if (tea5761_stereo(fe))
+		if (tea5761_stereo(fe, buffer))
 			*status |= TUNER_STATUS_STEREO;
+	}
+
+	return 0;
+}
+
+static int tea5761_get_rf_strength(struct dvb_frontend *fe, u16 *strength)
+{
+	unsigned char buffer[16];
+
+	*strength = 0;
 
-	tuner_dbg("tea5761: Signal strength: %d\n", signal);
+	if (0 == tea5761_read_status(fe, buffer))
+		*strength = tea5761_signal(fe, buffer);
 
 	return 0;
 }
@@ -266,6 +283,7 @@ static struct dvb_tuner_ops tea5761_tuner_ops = {
 	.release           = tea5761_release,
 	.get_frequency     = tea5761_get_frequency,
 	.get_status        = tea5761_get_status,
+	.get_rf_strength   = tea5761_get_rf_strength,
 };
 
 struct dvb_frontend *tea5761_attach(struct dvb_frontend *fe,