[media] tuner, xc2028: add support for get_afc()

Implement API support to return AFC frequency shift, as this device
supports it. The only other driver that implements it is tda9887,
and the frequency there is reported in Hz. So, use Hz also for this
tuner.

Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

1 files changed, 45 insertions, 1 deletions

diff --git a/drivers/media/common/tuners/tuner-xc2028.c b/drivers/media/common/tuners/tuner-xc2028.c
index 42fdf5c57091..4857e86259a1 100644
--- a/drivers/media/common/tuners/tuner-xc2028.c
+++ b/drivers/media/common/tuners/tuner-xc2028.c
@@ -924,7 +924,7 @@ static int xc2028_signal(struct dvb_frontend *fe, u16 *strength)
 		msleep(6);
 	}
 
-	/* Frequency was not locked */
+	/* Frequency didn't lock */
 	if (frq_lock == 2)
 		goto ret;
 
@@ -947,6 +947,49 @@ ret:
 	return rc;
 }
 
+static int xc2028_get_afc(struct dvb_frontend *fe, s32 *afc)
+{
+	struct xc2028_data *priv = fe->tuner_priv;
+	int i, rc;
+	u16 frq_lock = 0;
+	s16 afc_reg = 0;
+
+	rc = check_device_status(priv);
+	if (rc < 0)
+		return rc;
+
+	mutex_lock(&priv->lock);
+
+	/* Sync Lock Indicator */
+	for (i = 0; i < 3; i++) {
+		rc = xc2028_get_reg(priv, XREG_LOCK, &frq_lock);
+		if (rc < 0)
+			goto ret;
+
+		if (frq_lock)
+			break;
+		msleep(6);
+	}
+
+	/* Frequency didn't lock */
+	if (frq_lock == 2)
+		goto ret;
+
+	/* Get AFC */
+	rc = xc2028_get_reg(priv, XREG_FREQ_ERROR, &afc_reg);
+	if (rc < 0)
+		return rc;
+
+	*afc = afc_reg * 15625; /* Hz */
+
+	tuner_dbg("AFC is %d Hz\n", *afc);
+
+ret:
+	mutex_unlock(&priv->lock);
+
+	return rc;
+}
+
 #define DIV 15625
 
 static int generic_set_freq(struct dvb_frontend *fe, u32 freq /* in HZ */,
@@ -1392,6 +1435,7 @@ static const struct dvb_tuner_ops xc2028_dvb_tuner_ops = {
 	.release           = xc2028_dvb_release,
 	.get_frequency     = xc2028_get_frequency,
 	.get_rf_strength   = xc2028_signal,
+	.get_afc           = xc2028_get_afc,
 	.set_params        = xc2028_set_params,
 	.sleep             = xc2028_sleep,
 };