[media] rtl2832: wrap DVBv5 CNR to DVBv3 SNR

Change legacy DVBv3 read SNR to return values calculated by DVBv5
statistics.

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

1 files changed, 4 insertions, 38 deletions

diff --git a/drivers/media/dvb-frontends/rtl2832.c b/drivers/media/dvb-frontends/rtl2832.c
index 0a0899d2a6b2..18f150105438 100644
--- a/drivers/media/dvb-frontends/rtl2832.c
+++ b/drivers/media/dvb-frontends/rtl2832.c
@@ -791,49 +791,15 @@ err:
 
 static int rtl2832_read_snr(struct dvb_frontend *fe, u16 *snr)
 {
-        struct rtl2832_dev *dev = fe->demodulator_priv;
-        struct i2c_client *client = dev->client;
-        int ret, hierarchy, constellation;
-        u8 buf[2], tmp;
-        u16 tmp16;
-#define CONSTELLATION_NUM 3
-#define HIERARCHY_NUM 4
-        static const u32 snr_constant[CONSTELLATION_NUM][HIERARCHY_NUM] = {
-                { 85387325, 85387325, 85387325, 85387325 },
-                { 86676178, 86676178, 87167949, 87795660 },
-                { 87659938, 87659938, 87885178, 88241743 },
-        };
-
-        /* reports SNR in resolution of 0.1 dB */
-
-        ret = rtl2832_rd_reg(dev, 0x3c, 3, &tmp);
-        if (ret)
-                goto err;
-
-        constellation = (tmp >> 2) & 0x03; /* [3:2] */
-        if (constellation > CONSTELLATION_NUM - 1)
-                goto err;
-
-        hierarchy = (tmp >> 4) & 0x07; /* [6:4] */
-        if (hierarchy > HIERARCHY_NUM - 1)
-                goto err;
-
-        ret = rtl2832_rd_regs(dev, 0x0c, 4, buf, 2);
-        if (ret)
-                goto err;
-
-        tmp16 = buf[0] << 8 | buf[1];
+        struct dtv_frontend_properties *c = &fe->dtv_property_cache;
 
-        if (tmp16)
-                *snr = (snr_constant[constellation][hierarchy] -
-                                intlog10(tmp16)) / ((1 << 24) / 100);
+        /* report SNR in resolution of 0.1 dB */
+        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(&client->dev, "failed=%d\n", ret);
-        return ret;
 }
 
 static int rtl2832_read_ber(struct dvb_frontend *fe, u32 *ber)