diff options
Diffstat (limited to 'drivers/media/dvb-frontends/ts2020.c')
| -rw-r--r-- | drivers/media/dvb-frontends/ts2020.c | 138 |
1 files changed, 120 insertions, 18 deletions
diff --git a/drivers/media/dvb-frontends/ts2020.c b/drivers/media/dvb-frontends/ts2020.c index f674717fa921..277e1cff627b 100644 --- a/drivers/media/dvb-frontends/ts2020.c +++ b/drivers/media/dvb-frontends/ts2020.c @@ -32,6 +32,7 @@ struct ts2020_priv { struct regmap_config regmap_config; struct regmap *regmap; struct dvb_frontend *fe; + int (*get_agc_pwm)(struct dvb_frontend *fe, u8 *_agc_pwm); /* i2c details */ int i2c_address; struct i2c_adapter *i2c; @@ -313,32 +314,132 @@ static int ts2020_get_if_frequency(struct dvb_frontend *fe, u32 *frequency) return 0; } -/* read TS2020 signal strength */ -static int ts2020_read_signal_strength(struct dvb_frontend *fe, - u16 *signal_strength) +/* + * Get the tuner gain. + * @fe: The front end for which we're determining the gain + * @v_agc: The voltage of the AGC from the demodulator (0-2600mV) + * @_gain: Where to store the gain (in 0.001dB units) + * + * Returns 0 or a negative error code. + */ +static int ts2020_read_tuner_gain(struct dvb_frontend *fe, unsigned v_agc, + __s64 *_gain) { struct ts2020_priv *priv = fe->tuner_priv; - unsigned int utmp; - u16 sig_reading, sig_strength; - u8 rfgain, bbgain; + unsigned long gain1, gain2, gain3; + unsigned utmp; + int ret; + + /* Read the RF gain */ + ret = regmap_read(priv->regmap, 0x3d, &utmp); + if (ret < 0) + return ret; + gain1 = utmp & 0x1f; + + /* Read the baseband gain */ + ret = regmap_read(priv->regmap, 0x21, &utmp); + if (ret < 0) + return ret; + gain2 = utmp & 0x1f; + + switch (priv->tuner) { + case TS2020_M88TS2020: + gain1 = clamp_t(long, gain1, 0, 15); + gain2 = clamp_t(long, gain2, 0, 13); + v_agc = clamp_t(long, v_agc, 400, 1100); + + *_gain = -(gain1 * 2330 + + gain2 * 3500 + + v_agc * 24 / 10 * 10 + + 10000); + /* gain in range -19600 to -116850 in units of 0.001dB */ + break; + + case TS2020_M88TS2022: + ret = regmap_read(priv->regmap, 0x66, &utmp); + if (ret < 0) + return ret; + gain3 = (utmp >> 3) & 0x07; + + gain1 = clamp_t(long, gain1, 0, 15); + gain2 = clamp_t(long, gain2, 2, 16); + gain3 = clamp_t(long, gain3, 0, 6); + v_agc = clamp_t(long, v_agc, 600, 1600); + + *_gain = -(gain1 * 2650 + + gain2 * 3380 + + gain3 * 2850 + + v_agc * 176 / 100 * 10 - + 30000); + /* gain in range -47320 to -158950 in units of 0.001dB */ + break; + } + + return 0; +} + +/* + * Get the AGC information from the demodulator and use that to calculate the + * tuner gain. + */ +static int ts2020_get_tuner_gain(struct dvb_frontend *fe, __s64 *_gain) +{ + struct ts2020_priv *priv = fe->tuner_priv; + int v_agc = 0, ret; + u8 agc_pwm; - regmap_read(priv->regmap, 0x3d, &utmp); - rfgain = utmp & 0x1f; - regmap_read(priv->regmap, 0x21, &utmp); - bbgain = utmp & 0x1f; + /* Read the AGC PWM rate from the demodulator */ + if (priv->get_agc_pwm) { + ret = priv->get_agc_pwm(fe, &agc_pwm); + if (ret < 0) + return ret; - if (rfgain > 15) - rfgain = 15; - if (bbgain > 13) - bbgain = 13; + switch (priv->tuner) { + case TS2020_M88TS2020: + v_agc = (int)agc_pwm * 20 - 1166; + break; + case TS2020_M88TS2022: + v_agc = (int)agc_pwm * 16 - 670; + break; + } - sig_reading = rfgain * 2 + bbgain * 3; + if (v_agc < 0) + v_agc = 0; + } - sig_strength = 40 + (64 - sig_reading) * 50 / 64 ; + return ts2020_read_tuner_gain(fe, v_agc, _gain); +} - /* cook the value to be suitable for szap-s2 human readable output */ - *signal_strength = sig_strength * 1000; +/* + * Read TS2020 signal strength in v3 format. + */ +static int ts2020_read_signal_strength(struct dvb_frontend *fe, + u16 *signal_strength) +{ + unsigned strength; + __s64 gain; + int ret; + + /* Determine the total gain of the tuner */ + ret = ts2020_get_tuner_gain(fe, &gain); + if (ret < 0) + return ret; + + /* Calculate the signal strength based on the total gain of the tuner */ + if (gain < -85000) + /* 0%: no signal or weak signal */ + strength = 0; + else if (gain < -65000) + /* 0% - 60%: weak signal */ + strength = 0 + (85000 + gain) * 3 / 1000; + else if (gain < -45000) + /* 60% - 90%: normal signal */ + strength = 60 + (65000 + gain) * 3 / 2000; + else + /* 90% - 99%: strong signal */ + strength = 90 + (45000 + gain) / 5000; + *signal_strength = strength * 65535 / 100; return 0; } @@ -442,6 +543,7 @@ static int ts2020_probe(struct i2c_client *client, dev->clk_out_div = pdata->clk_out_div; dev->frequency_div = pdata->frequency_div; dev->fe = fe; + dev->get_agc_pwm = pdata->get_agc_pwm; fe->tuner_priv = dev; dev->client = client; |