diff options
Diffstat (limited to 'drivers/media/dvb/pt1/va1j5jf8007s.c')
| -rw-r--r-- | drivers/media/dvb/pt1/va1j5jf8007s.c | 55 |
1 files changed, 55 insertions, 0 deletions
diff --git a/drivers/media/dvb/pt1/va1j5jf8007s.c b/drivers/media/dvb/pt1/va1j5jf8007s.c index 2db940f8635..a20927e10d7 100644 --- a/drivers/media/dvb/pt1/va1j5jf8007s.c +++ b/drivers/media/dvb/pt1/va1j5jf8007s.c @@ -48,6 +48,60 @@ struct va1j5jf8007s_state { enum va1j5jf8007s_tune_state tune_state; }; +static int va1j5jf8007s_read_snr(struct dvb_frontend *fe, u16 *snr) +{ + struct va1j5jf8007s_state *state; + u8 addr; + int i; + u8 write_buf[1], read_buf[1]; + struct i2c_msg msgs[2]; + s32 word, x1, x2, x3, x4, x5, y; + + state = fe->demodulator_priv; + addr = state->config->demod_address; + + word = 0; + for (i = 0; i < 2; i++) { + write_buf[0] = 0xbc + i; + + msgs[0].addr = addr; + msgs[0].flags = 0; + msgs[0].len = sizeof(write_buf); + msgs[0].buf = write_buf; + + msgs[1].addr = addr; + msgs[1].flags = I2C_M_RD; + msgs[1].len = sizeof(read_buf); + msgs[1].buf = read_buf; + + if (i2c_transfer(state->adap, msgs, 2) != 2) + return -EREMOTEIO; + + word <<= 8; + word |= read_buf[0]; + } + + word -= 3000; + if (word < 0) + word = 0; + + x1 = int_sqrt(word << 16) * ((15625ll << 21) / 1000000); + x2 = (s64)x1 * x1 >> 31; + x3 = (s64)x2 * x1 >> 31; + x4 = (s64)x2 * x2 >> 31; + x5 = (s64)x4 * x1 >> 31; + + y = (58857ll << 23) / 1000; + y -= (s64)x1 * ((89565ll << 24) / 1000) >> 30; + y += (s64)x2 * ((88977ll << 24) / 1000) >> 28; + y -= (s64)x3 * ((50259ll << 25) / 1000) >> 27; + y += (s64)x4 * ((14341ll << 27) / 1000) >> 27; + y -= (s64)x5 * ((16346ll << 30) / 10000) >> 28; + + *snr = y < 0 ? 0 : y >> 15; + return 0; +} + static int va1j5jf8007s_get_frontend_algo(struct dvb_frontend *fe) { return DVBFE_ALGO_HW; @@ -536,6 +590,7 @@ static struct dvb_frontend_ops va1j5jf8007s_ops = { FE_CAN_GUARD_INTERVAL_AUTO | FE_CAN_HIERARCHY_AUTO, }, + .read_snr = va1j5jf8007s_read_snr, .get_frontend_algo = va1j5jf8007s_get_frontend_algo, .read_status = va1j5jf8007s_read_status, .tune = va1j5jf8007s_tune, |