Use DVBv5 CNR logic to calculate DVBv3 SNR too.
Signed-off-by: Antti Palosaari <cr...@iki.fi>
---
drivers/media/dvb-frontends/m88ds3103.c | 74 ++-------------------------------
1 file changed, 4 insertions(+), 70 deletions(-)
diff --git a/drivers/media/dvb-frontends/m88ds3103.c
b/drivers/media/dvb-frontends/m88ds3103.c
index 980a89e..381a8ad 100644
--- a/drivers/media/dvb-frontends/m88ds3103.c
+++ b/drivers/media/dvb-frontends/m88ds3103.c
@@ -984,80 +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)
--
http://palosaari.fi/
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