[media] m88ds3103: implement DVBv5 CNR statistics

Implement DVBv5 CNR statistics.
Wrap legacy DVBv3 SNR to DVBv5 CNR.

Signed-off-by: Antti Palosaari <crope@iki.fi>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>

drivers/media/dvb-frontends/m88ds3103.c

@@ -190,8 +190,9 @@ static int m88ds3103_read_status(struct dvb_frontend *fe, fe_status_t *status)
 {
 	struct m88ds3103_priv *priv = fe->demodulator_priv;
 	struct dtv_frontend_properties *c = &fe->dtv_property_cache;
-	int ret;
+	int ret, i, itmp;
 	u8 u8tmp;
+	u8 buf[3];
 
 	*status = 0;
 
@@ -233,6 +234,77 @@ static int m88ds3103_read_status(struct dvb_frontend *fe, fe_status_t *status)
 	dev_dbg(&priv->i2c->dev, "%s: lock=%02x status=%02x\n",
 			__func__, u8tmp, *status);
 
+	/* CNR */
+	if (priv->fe_status & FE_HAS_VITERBI) {
+		unsigned int cnr, noise, signal, noise_tot, signal_tot;
+
+		cnr = 0;
+		/* more iterations for more accurate estimation */
+		#define M88DS3103_SNR_ITERATIONS 3
+
+		switch (c->delivery_system) {
+		case SYS_DVBS:
+			itmp = 0;
+
+			for (i = 0; i < M88DS3103_SNR_ITERATIONS; i++) {
+				ret = m88ds3103_rd_reg(priv, 0xff, &buf[0]);
+				if (ret)
+					goto err;
+
+				itmp += buf[0];
+			}
+
+			/* use of single register limits max value to 15 dB */
+			/* SNR(X) dB = 10 * ln(X) / ln(10) dB */
+			itmp = DIV_ROUND_CLOSEST(itmp, 8 * M88DS3103_SNR_ITERATIONS);
+			if (itmp)
+				cnr = div_u64((u64) 10000 * intlog2(itmp), intlog2(10));
+			break;
+		case SYS_DVBS2:
+			noise_tot = 0;
+			signal_tot = 0;
+
+			for (i = 0; i < M88DS3103_SNR_ITERATIONS; i++) {
+				ret = m88ds3103_rd_regs(priv, 0x8c, buf, 3);
+				if (ret)
+					goto err;
+
+				noise = buf[1] << 6;    /* [13:6] */
+				noise |= buf[0] & 0x3f; /*  [5:0] */
+				noise >>= 2;
+				signal = buf[2] * buf[2];
+				signal >>= 1;
+
+				noise_tot += noise;
+				signal_tot += signal;
+			}
+
+			noise = noise_tot / M88DS3103_SNR_ITERATIONS;
+			signal = signal_tot / M88DS3103_SNR_ITERATIONS;
+
+			/* SNR(X) dB = 10 * log10(X) dB */
+			if (signal > noise) {
+				itmp = signal / noise;
+				cnr = div_u64((u64) 10000 * intlog10(itmp), (1 << 24));
+			}
+			break;
+		default:
+			dev_dbg(&priv->i2c->dev,
+				"%s: invalid delivery_system\n", __func__);
+			ret = -EINVAL;
+			goto err;
+		}
+
+		if (cnr) {
+			c->cnr.stat[0].scale = FE_SCALE_DECIBEL;
+			c->cnr.stat[0].svalue = cnr;
+		} else {
+			c->cnr.stat[0].scale = FE_SCALE_NOT_AVAILABLE;
+		}
+	} else {
+		c->cnr.stat[0].scale = FE_SCALE_NOT_AVAILABLE;
+	}
+
 	return 0;
 err:
 	dev_dbg(&priv->i2c->dev, "%s: failed=%d\n", __func__, ret);
@@ -577,6 +649,7 @@ err:
 static int m88ds3103_init(struct dvb_frontend *fe)
 {
 	struct m88ds3103_priv *priv = fe->demodulator_priv;
+	struct dtv_frontend_properties *c = &fe->dtv_property_cache;
 	int ret, len, remaining;
 	const struct firmware *fw = NULL;
 	u8 *fw_file;
@@ -684,7 +757,9 @@ static int m88ds3103_init(struct dvb_frontend *fe)
 skip_fw_download:
 	/* warm state */
 	priv->warm = true;
-
+	/* init stats here in order signal app which stats are supported */
+	c->cnr.len = 1;
+	c->cnr.stat[0].scale = FE_SCALE_NOT_AVAILABLE;
 	return 0;
 
 error_fw_release:
@@ -702,6 +777,7 @@ static int m88ds3103_sleep(struct dvb_frontend *fe)
 
 	dev_dbg(&priv->i2c->dev, "%s:\n", __func__);
 
+	priv->fe_status = 0;
 	priv->delivery_system = SYS_UNDEFINED;
 
 	/* TS Hi-Z */
@@ -908,80 +984,14 @@ err:
 
 static int m88ds3103_read_snr(struct dvb_frontend *fe, u16 *snr)
 {
-	struct m88ds3103_priv *priv = fe->demodulator_priv;
 	struct dtv_frontend_properties *c = &fe->dtv_property_cache;
-	int ret, i, tmp;
-	u8 buf[3];
-	u16 noise, signal;
-	u32 noise_tot, signal_tot;
 
-	dev_dbg(&priv->i2c->dev, "%s:\n", __func__);
-	/* reports SNR in resolution of 0.1 dB */
-
-	/* more iterations for more accurate estimation */
-	#define M88DS3103_SNR_ITERATIONS 3
-
-	switch (c->delivery_system) {
-	case SYS_DVBS:
-		tmp = 0;
-
-		for (i = 0; i < M88DS3103_SNR_ITERATIONS; i++) {
-			ret = m88ds3103_rd_reg(priv, 0xff, &buf[0]);
-			if (ret)
-				goto err;
-
-			tmp += buf[0];
-		}
-
-		/* use of one register limits max value to 15 dB */
-		/* SNR(X) dB = 10 * ln(X) / ln(10) dB */
-		tmp = DIV_ROUND_CLOSEST(tmp, 8 * M88DS3103_SNR_ITERATIONS);
-		if (tmp)
-			*snr = div_u64((u64) 100 * intlog2(tmp), intlog2(10));
-		else
-			*snr = 0;
-		break;
-	case SYS_DVBS2:
-		noise_tot = 0;
-		signal_tot = 0;
-
-		for (i = 0; i < M88DS3103_SNR_ITERATIONS; i++) {
-			ret = m88ds3103_rd_regs(priv, 0x8c, buf, 3);
-			if (ret)
-				goto err;
-
-			noise = buf[1] << 6;    /* [13:6] */
-			noise |= buf[0] & 0x3f; /*  [5:0] */
-			noise >>= 2;
-			signal = buf[2] * buf[2];
-			signal >>= 1;
-
-			noise_tot += noise;
-			signal_tot += signal;
-		}
-
-		noise = noise_tot / M88DS3103_SNR_ITERATIONS;
-		signal = signal_tot / M88DS3103_SNR_ITERATIONS;
-
-		/* SNR(X) dB = 10 * log10(X) dB */
-		if (signal > noise) {
-			tmp = signal / noise;
-			*snr = div_u64((u64) 100 * intlog10(tmp), (1 << 24));
-		} else {
-			*snr = 0;
-		}
-		break;
-	default:
-		dev_dbg(&priv->i2c->dev, "%s: invalid delivery_system\n",
-				__func__);
-		ret = -EINVAL;
-		goto err;
-	}
+	if (c->cnr.stat[0].scale == FE_SCALE_DECIBEL)
+		*snr = div_s64(c->cnr.stat[0].svalue, 100);
+	else
+		*snr = 0;
 
 	return 0;
-err:
-	dev_dbg(&priv->i2c->dev, "%s: failed=%d\n", __func__, ret);
-	return ret;
 }
 
 static int m88ds3103_read_ber(struct dvb_frontend *fe, u32 *ber)