redonkable/alistair23-linux
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media: af9013: dvbv5 signal strength

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Implement dvbv5 signal strength estimate. We know tuner dependent
-80dBm and -50dBm agc values, construct line equation and use it to
map agc value to signal strength estimate.

Signed-off-by: Antti Palosaari <crope@iki.fi>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
This commit is contained in:
Antti Palosaari 2017-06-18 01:17:49 -04:00 committed by Mauro Carvalho Chehab
parent 7903fbe3a6
commit 943a720f5c
1 changed files with 81 additions and 2 deletions
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83
drivers/media/dvb-frontends/af9013.c
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@ -41,8 +41,11 @@ struct af9013_state {
u16 snr;
u32 bandwidth_hz;
enum fe_status fe_status;
/* RF and IF AGC limits used for signal strength calc */
u8 strength_en, rf_agc_50, rf_agc_80, if_agc_50, if_agc_80;
unsigned long set_frontend_jiffies;
unsigned long read_status_jiffies;
unsigned long strength_jiffies;
bool first_tune;
bool i2c_gate_state;
unsigned int statistics_step:3;
@ -751,8 +754,12 @@ static int af9013_read_status(struct dvb_frontend *fe, enum fe_status *status)
{
struct af9013_state *state = fe->demodulator_priv;
struct i2c_client *client = state->client;
int ret;
unsigned int utmp, utmp1;
struct dtv_frontend_properties *c = &fe->dtv_property_cache;
int ret, stmp1;
unsigned int utmp, utmp1, utmp2, utmp3, utmp4;
u8 buf[2];
dev_dbg(&client->dev, "\n");
/*
* Return status from the cache if it is younger than 2000ms with the
@ -791,6 +798,77 @@ static int af9013_read_status(struct dvb_frontend *fe, enum fe_status *status)
*status = utmp1;
}
/* Signal strength */
switch (state->strength_en) {
case 0:
/* Check if we support signal strength */
ret = regmap_read(state->regmap, 0x9bee, &utmp);
if (ret)
goto err;
if ((utmp >> 0) & 0x01) {
/* Read agc values for signal strength estimation */
ret = regmap_read(state->regmap, 0x9bbd, &utmp1);
if (ret)
goto err;
ret = regmap_read(state->regmap, 0x9bd0, &utmp2);
if (ret)
goto err;
ret = regmap_read(state->regmap, 0x9be2, &utmp3);
if (ret)
goto err;
ret = regmap_read(state->regmap, 0x9be4, &utmp4);
if (ret)
goto err;
state->rf_agc_50 = utmp1;
state->rf_agc_80 = utmp2;
state->if_agc_50 = utmp3;
state->if_agc_80 = utmp4;
dev_dbg(&client->dev,
"rf_agc_50 %u, rf_agc_80 %u, if_agc_50 %u, if_agc_80 %u\n",
utmp1, utmp2, utmp3, utmp4);
state->strength_en = 1;
} else {
/* Signal strength is not supported */
state->strength_en = 2;
break;
}
/* Fall through */
case 1:
if (time_is_after_jiffies(state->strength_jiffies + msecs_to_jiffies(2000)))
break;
/* Read value */
ret = regmap_bulk_read(state->regmap, 0xd07c, buf, 2);
if (ret)
goto err;
/*
* Construct line equation from tuner dependent -80/-50 dBm agc
* limits and use it to map current agc value to dBm estimate
*/
#define agc_gain (buf[0] + buf[1])
#define agc_gain_50dbm (state->rf_agc_50 + state->if_agc_50)
#define agc_gain_80dbm (state->rf_agc_80 + state->if_agc_80)
stmp1 = 30000 * (agc_gain - agc_gain_80dbm) /
(agc_gain_50dbm - agc_gain_80dbm) - 80000;
dev_dbg(&client->dev,
"strength %d, agc_gain %d, agc_gain_50dbm %d, agc_gain_80dbm %d\n",
stmp1, agc_gain, agc_gain_50dbm, agc_gain_80dbm);
state->strength_jiffies = jiffies;
c->strength.stat[0].scale = FE_SCALE_DECIBEL;
c->strength.stat[0].svalue = stmp1;
break;
default:
c->strength.stat[0].scale = FE_SCALE_NOT_AVAILABLE;
break;
}
return 0;
err:
dev_dbg(&client->dev, "failed %d\n", ret);
@ -1512,6 +1590,7 @@ static int af9013_probe(struct i2c_client *client,
/* Init stats to indicate which stats are supported */
c = &state->fe.dtv_property_cache;
c->strength.len = 1;
c->cnr.len = 1;
dev_info(&client->dev, "Afatech AF9013 successfully attached\n");