[media] mn88472: implement cnr statistics

Implement DVBv5 CNR.

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

diff --git a/drivers/media/dvb-frontends/mn88472.c b/drivers/media/dvb-frontends/mn88472.c
index 25dd742..c7e5f63 100644 (file)
--- a/drivers/media/dvb-frontends/mn88472.c
+++ b/drivers/media/dvb-frontends/mn88472.c
@@ -28,9 +28,9 @@ static int mn88472_read_status(struct dvb_frontend *fe, enum fe_status *status)
        struct i2c_client *client = fe->demodulator_priv;
        struct mn88472_dev *dev = i2c_get_clientdata(client);
        struct dtv_frontend_properties *c = &fe->dtv_property_cache;
-       int ret, i;
-       unsigned int utmp, utmp1;
-       u8 buf[2];
+       int ret, i, stmp;
+       unsigned int utmp, utmp1, utmp2;
+       u8 buf[5];
 
        if (!dev->active) {
                ret = -EAGAIN;
@@ -96,6 +96,89 @@ static int mn88472_read_status(struct dvb_frontend *fe, enum fe_status *status)
                c->strength.stat[0].scale = FE_SCALE_NOT_AVAILABLE;
        }
 
+       /* CNR */
+       if (*status & FE_HAS_VITERBI && c->delivery_system == SYS_DVBT) {
+               /* DVB-T CNR */
+               ret = regmap_bulk_read(dev->regmap[0], 0x9c, buf, 2);
+               if (ret)
+                       goto err;
+
+               utmp = buf[0] << 8 | buf[1] << 0;
+               if (utmp) {
+                       /* CNR[dB]: 10 * log10(65536 / value) + 2 */
+                       /* log10(65536) = 80807124, 0.2 = 3355443 */
+                       stmp = ((u64)80807124 - intlog10(utmp) + 3355443)
+                              * 10000 >> 24;
+
+                       dev_dbg(&client->dev, "cnr=%d value=%u\n", stmp, utmp);
+               } else {
+                       stmp = 0;
+               }
+
+               c->cnr.stat[0].svalue = stmp;
+               c->cnr.stat[0].scale = FE_SCALE_DECIBEL;
+       } else if (*status & FE_HAS_VITERBI &&
+                  c->delivery_system == SYS_DVBT2) {
+               /* DVB-T2 CNR */
+               for (i = 0; i < 3; i++) {
+                       ret = regmap_bulk_read(dev->regmap[2], 0xbc + i,
+                                              &buf[i], 1);
+                       if (ret)
+                               goto err;
+               }
+
+               utmp = buf[1] << 8 | buf[2] << 0;
+               utmp1 = (buf[0] >> 2) & 0x01; /* 0=SISO, 1=MISO */
+               if (utmp) {
+                       if (utmp1) {
+                               /* CNR[dB]: 10 * log10(16384 / value) - 6 */
+                               /* log10(16384) = 70706234, 0.6 = 10066330 */
+                               stmp = ((u64)70706234 - intlog10(utmp)
+                                      - 10066330) * 10000 >> 24;
+                               dev_dbg(&client->dev, "cnr=%d value=%u MISO\n",
+                                       stmp, utmp);
+                       } else {
+                               /* CNR[dB]: 10 * log10(65536 / value) + 2 */
+                               /* log10(65536) = 80807124, 0.2 = 3355443 */
+                               stmp = ((u64)80807124 - intlog10(utmp)
+                                      + 3355443) * 10000 >> 24;
+
+                               dev_dbg(&client->dev, "cnr=%d value=%u SISO\n",
+                                       stmp, utmp);
+                       }
+               } else {
+                       stmp = 0;
+               }
+
+               c->cnr.stat[0].svalue = stmp;
+               c->cnr.stat[0].scale = FE_SCALE_DECIBEL;
+       } else if (*status & FE_HAS_VITERBI &&
+                  c->delivery_system == SYS_DVBC_ANNEX_A) {
+               /* DVB-C CNR */
+               ret = regmap_bulk_read(dev->regmap[1], 0xa1, buf, 4);
+               if (ret)
+                       goto err;
+
+               utmp1 = buf[0] << 8 | buf[1] << 0; /* signal */
+               utmp2 = buf[2] << 8 | buf[3] << 0; /* noise */
+               if (utmp1 && utmp2) {
+                       /* CNR[dB]: 10 * log10(8 * (signal / noise)) */
+                       /* log10(8) = 15151336 */
+                       stmp = ((u64)15151336 + intlog10(utmp1)
+                              - intlog10(utmp2)) * 10000 >> 24;
+
+                       dev_dbg(&client->dev, "cnr=%d signal=%u noise=%u\n",
+                               stmp, utmp1, utmp2);
+               } else {
+                       stmp = 0;
+               }
+
+               c->cnr.stat[0].svalue = stmp;
+               c->cnr.stat[0].scale = FE_SCALE_DECIBEL;
+       } else {
+               c->cnr.stat[0].scale = FE_SCALE_NOT_AVAILABLE;
+       }
+
        return 0;
 err:
        dev_dbg(&client->dev, "failed=%d\n", ret);
@@ -570,6 +653,7 @@ static int mn88472_probe(struct i2c_client *client,
        /* Init stats to indicate which stats are supported */
        c = &dev->fe.dtv_property_cache;
        c->strength.len = 1;
+       c->cnr.len = 1;
 
        /* Setup callbacks */
        pdata->get_dvb_frontend = mn88472_get_dvb_frontend;

diff --git a/drivers/media/dvb-frontends/mn88472_priv.h b/drivers/media/dvb-frontends/mn88472_priv.h
index cdf2597..fb50f56 100644 (file)
--- a/drivers/media/dvb-frontends/mn88472_priv.h
+++ b/drivers/media/dvb-frontends/mn88472_priv.h
@@ -18,6 +18,7 @@
 #define MN88472_PRIV_H
 
 #include "dvb_frontend.h"
+#include "dvb_math.h"
 #include "mn88472.h"
 #include <linux/firmware.h>
 #include <linux/regmap.h>