diff options
| author | Daniel Scheller <d.scheller@gmx.net> | 2017-07-03 13:20:57 -0400 |
|---|---|---|
| committer | Mauro Carvalho Chehab <mchehab@s-opensource.com> | 2017-07-20 12:59:50 -0400 |
| commit | 19bb3b718f02ff2fa38e3222cf62c9c3f46d2527 (patch) | |
| tree | 2684225a26d76a8e6a2c8d6639691e05ae8d7e27 /drivers/media/dvb-frontends/stv0910.c | |
| parent | ea71c62bdef59004a2fd835545cd02bbeb699f83 (diff) | |
media: dvb-frontends/stv0910: Add demod-only signal strength reporting
Original code at least has some signed/unsigned issues, resulting in
values like 32dBm. Implement signal strength readout to work without
asking the attached tuner, and use a lookup table instead of log calc.
Values reported appear plausible, gathered from feedback from several
testers.
Signed-off-by: Daniel Scheller <d.scheller@gmx.net>
Tested-by: Richard Scobie <r.scobie@clear.net.nz>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Diffstat (limited to 'drivers/media/dvb-frontends/stv0910.c')
| -rw-r--r-- | drivers/media/dvb-frontends/stv0910.c | 48 |
1 files changed, 44 insertions, 4 deletions
diff --git a/drivers/media/dvb-frontends/stv0910.c b/drivers/media/dvb-frontends/stv0910.c index dc848ebe1a44..dc4d829bb47a 100644 --- a/drivers/media/dvb-frontends/stv0910.c +++ b/drivers/media/dvb-frontends/stv0910.c @@ -135,7 +135,7 @@ struct sinit_table { struct slookup { s16 value; - u16 reg_value; + u32 reg_value; }; static inline int i2c_write(struct i2c_adapter *adap, u8 adr, @@ -327,6 +327,25 @@ struct slookup s2_sn_lookup[] = { { 510, 463 }, /*C/N=51.0dB*/ }; +struct slookup padc_lookup[] = { + { 0, 118000 }, /* PADC=+0dBm */ + { -100, 93600 }, /* PADC=-1dBm */ + { -200, 74500 }, /* PADC=-2dBm */ + { -300, 59100 }, /* PADC=-3dBm */ + { -400, 47000 }, /* PADC=-4dBm */ + { -500, 37300 }, /* PADC=-5dBm */ + { -600, 29650 }, /* PADC=-6dBm */ + { -700, 23520 }, /* PADC=-7dBm */ + { -900, 14850 }, /* PADC=-9dBm */ + { -1100, 9380 }, /* PADC=-11dBm */ + { -1300, 5910 }, /* PADC=-13dBm */ + { -1500, 3730 }, /* PADC=-15dBm */ + { -1700, 2354 }, /* PADC=-17dBm */ + { -1900, 1485 }, /* PADC=-19dBm */ + { -2000, 1179 }, /* PADC=-20dBm */ + { -2100, 1000 }, /* PADC=-21dBm */ +}; + /********************************************************************* * Tracking carrier loop carrier QPSK 1/4 to 8PSK 9/10 long Frame *********************************************************************/ @@ -567,7 +586,7 @@ static int tracking_optimization(struct stv *state) } static s32 table_lookup(struct slookup *table, - int table_size, u16 reg_value) + int table_size, u32 reg_value) { s32 value; int imin = 0; @@ -1300,11 +1319,32 @@ static int read_ber(struct dvb_frontend *fe) static void read_signal_strength(struct dvb_frontend *fe) { - /* FIXME: add signal strength algo */ struct stv *state = fe->demodulator_priv; struct dtv_frontend_properties *p = &state->fe.dtv_property_cache; + s64 strength; + u8 reg[2]; + u16 agc; + s32 padc, power = 0; + int i; - p->strength.stat[0].scale = FE_SCALE_NOT_AVAILABLE; + read_regs(state, RSTV0910_P2_AGCIQIN1 + state->regoff, reg, 2); + + agc = (((u32) reg[0]) << 8) | reg[1]; + + for (i = 0; i < 5; i += 1) { + read_regs(state, RSTV0910_P2_POWERI + state->regoff, reg, 2); + power += (u32) reg[0] * (u32) reg[0] + + (u32) reg[1] * (u32) reg[1]; + usleep_range(3000, 4000); + } + power /= 5; + + padc = table_lookup(padc_lookup, ARRAY_SIZE(padc_lookup), power) + 352; + + strength = (padc - agc); + + p->strength.stat[0].scale = FE_SCALE_DECIBEL; + p->strength.stat[0].uvalue = strength; } static int read_status(struct dvb_frontend *fe, enum fe_status *status) |