From 25188bd0e66f244d8111c4459f2c2f262a13d272 Mon Sep 17 00:00:00 2001 From: Mauro Carvalho Chehab Date: Wed, 16 Jan 2013 15:12:05 -0300 Subject: [media] mb86a20s: add CNR measurement Add Signal/Noise ratio measurement. On this device, a global measure is taken by the demod. It also provides per-layer CNR measurements, based on Modulation Error measures (MER). Reviewed-by: Antti Palosaari Signed-off-by: Mauro Carvalho Chehab --- drivers/media/dvb-frontends/mb86a20s.c | 336 ++++++++++++++++++++++++++++++++- 1 file changed, 334 insertions(+), 2 deletions(-) (limited to 'drivers/media/dvb-frontends') diff --git a/drivers/media/dvb-frontends/mb86a20s.c b/drivers/media/dvb-frontends/mb86a20s.c index c68e4676e5fd..4f3e222a2bcf 100644 --- a/drivers/media/dvb-frontends/mb86a20s.c +++ b/drivers/media/dvb-frontends/mb86a20s.c @@ -118,10 +118,12 @@ static struct regdata mb86a20s_init[] = { { 0x50, 0xb5 }, { 0x51, 0xff }, { 0x50, 0xb6 }, { 0x51, 0xff }, { 0x50, 0xb7 }, { 0x51, 0xff }, - { 0x50, 0x50 }, { 0x51, 0x02 }, + + { 0x50, 0x50 }, { 0x51, 0x02 }, /* MER manual mode */ { 0x50, 0x51 }, { 0x51, 0x04 }, /* MER symbol 4 */ { 0x45, 0x04 }, /* CN symbol 4 */ - { 0x48, 0x04 }, + { 0x48, 0x04 }, /* CN manual mode */ + { 0x50, 0xd5 }, { 0x51, 0x01 }, /* Serial */ { 0x50, 0xd6 }, { 0x51, 0x1f }, { 0x50, 0xd2 }, { 0x51, 0x03 }, @@ -891,6 +893,330 @@ static int mb86a20s_get_ber_before_vterbi(struct dvb_frontend *fe, return 0; } +struct linear_segments { + unsigned x, y; +}; + +/* + * All tables below return a dB/1000 measurement + */ + +static struct linear_segments cnr_to_db_table[] = { + { 19648, 0}, + { 18187, 1000}, + { 16534, 2000}, + { 14823, 3000}, + { 13161, 4000}, + { 11622, 5000}, + { 10279, 6000}, + { 9089, 7000}, + { 8042, 8000}, + { 7137, 9000}, + { 6342, 10000}, + { 5641, 11000}, + { 5030, 12000}, + { 4474, 13000}, + { 3988, 14000}, + { 3556, 15000}, + { 3180, 16000}, + { 2841, 17000}, + { 2541, 18000}, + { 2276, 19000}, + { 2038, 20000}, + { 1800, 21000}, + { 1625, 22000}, + { 1462, 23000}, + { 1324, 24000}, + { 1175, 25000}, + { 1063, 26000}, + { 980, 27000}, + { 907, 28000}, + { 840, 29000}, + { 788, 30000}, +}; + +static struct linear_segments cnr_64qam_table[] = { + { 3922688, 0}, + { 3920384, 1000}, + { 3902720, 2000}, + { 3894784, 3000}, + { 3882496, 4000}, + { 3872768, 5000}, + { 3858944, 6000}, + { 3851520, 7000}, + { 3838976, 8000}, + { 3829248, 9000}, + { 3818240, 10000}, + { 3806976, 11000}, + { 3791872, 12000}, + { 3767040, 13000}, + { 3720960, 14000}, + { 3637504, 15000}, + { 3498496, 16000}, + { 3296000, 17000}, + { 3031040, 18000}, + { 2715392, 19000}, + { 2362624, 20000}, + { 1963264, 21000}, + { 1649664, 22000}, + { 1366784, 23000}, + { 1120768, 24000}, + { 890880, 25000}, + { 723456, 26000}, + { 612096, 27000}, + { 518912, 28000}, + { 448256, 29000}, + { 388864, 30000}, +}; + +static struct linear_segments cnr_16qam_table[] = { + { 5314816, 0}, + { 5219072, 1000}, + { 5118720, 2000}, + { 4998912, 3000}, + { 4875520, 4000}, + { 4736000, 5000}, + { 4604160, 6000}, + { 4458752, 7000}, + { 4300288, 8000}, + { 4092928, 9000}, + { 3836160, 10000}, + { 3521024, 11000}, + { 3155968, 12000}, + { 2756864, 13000}, + { 2347008, 14000}, + { 1955072, 15000}, + { 1593600, 16000}, + { 1297920, 17000}, + { 1043968, 18000}, + { 839680, 19000}, + { 672256, 20000}, + { 523008, 21000}, + { 424704, 22000}, + { 345088, 23000}, + { 280064, 24000}, + { 221440, 25000}, + { 179712, 26000}, + { 151040, 27000}, + { 128512, 28000}, + { 110080, 29000}, + { 95744, 30000}, +}; + +struct linear_segments cnr_qpsk_table[] = { + { 2834176, 0}, + { 2683648, 1000}, + { 2536960, 2000}, + { 2391808, 3000}, + { 2133248, 4000}, + { 1906176, 5000}, + { 1666560, 6000}, + { 1422080, 7000}, + { 1189632, 8000}, + { 976384, 9000}, + { 790272, 10000}, + { 633344, 11000}, + { 505600, 12000}, + { 402944, 13000}, + { 320768, 14000}, + { 255488, 15000}, + { 204032, 16000}, + { 163072, 17000}, + { 130304, 18000}, + { 105216, 19000}, + { 83456, 20000}, + { 65024, 21000}, + { 52480, 22000}, + { 42752, 23000}, + { 34560, 24000}, + { 27136, 25000}, + { 22016, 26000}, + { 18432, 27000}, + { 15616, 28000}, + { 13312, 29000}, + { 11520, 30000}, +}; + +static u32 interpolate_value(u32 value, struct linear_segments *segments, + unsigned len) +{ + u64 tmp64; + u32 dx, dy; + int i, ret; + + if (value >= segments[0].x) + return segments[0].y; + if (value < segments[len-1].x) + return segments[len-1].y; + + for (i = 1; i < len - 1; i++) { + /* If value is identical, no need to interpolate */ + if (value == segments[i].x) + return segments[i].y; + if (value > segments[i].x) + break; + } + + /* Linear interpolation between the two (x,y) points */ + dy = segments[i].y - segments[i - 1].y; + dx = segments[i - 1].x - segments[i].x; + tmp64 = value - segments[i].x; + tmp64 *= dy; + do_div(tmp64, dx); + ret = segments[i].y - tmp64; + + return ret; +} + +static int mb86a20s_get_main_CNR(struct dvb_frontend *fe) +{ + struct mb86a20s_state *state = fe->demodulator_priv; + struct dtv_frontend_properties *c = &fe->dtv_property_cache; + u32 cnr_linear, cnr; + int rc, val; + + /* Check if CNR is available */ + rc = mb86a20s_readreg(state, 0x45); + if (rc < 0) + return rc; + + if (!(rc & 0x40)) { + dev_info(&state->i2c->dev, "%s: CNR is not available yet.\n", + __func__); + return -EBUSY; + } + val = rc; + + rc = mb86a20s_readreg(state, 0x46); + if (rc < 0) + return rc; + cnr_linear = rc << 8; + + rc = mb86a20s_readreg(state, 0x46); + if (rc < 0) + return rc; + cnr_linear |= rc; + + cnr = interpolate_value(cnr_linear, + cnr_to_db_table, ARRAY_SIZE(cnr_to_db_table)); + + c->cnr.stat[0].scale = FE_SCALE_DECIBEL; + c->cnr.stat[0].svalue = cnr; + + dev_dbg(&state->i2c->dev, "%s: CNR is %d.%03d dB (%d)\n", + __func__, cnr / 1000, cnr % 1000, cnr_linear); + + /* CNR counter reset */ + rc = mb86a20s_writereg(state, 0x45, val | 0x10); + if (rc < 0) + return rc; + rc = mb86a20s_writereg(state, 0x45, val & 0x6f); + + return rc; +} + +static int mb86a20s_get_per_layer_CNR(struct dvb_frontend *fe) +{ + struct mb86a20s_state *state = fe->demodulator_priv; + struct dtv_frontend_properties *c = &fe->dtv_property_cache; + u32 mer, cnr; + int rc, val, i; + struct linear_segments *segs; + unsigned segs_len; + + dev_dbg(&state->i2c->dev, "%s called.\n", __func__); + + /* Check if the measures are already available */ + rc = mb86a20s_writereg(state, 0x50, 0x5b); + if (rc < 0) + return rc; + rc = mb86a20s_readreg(state, 0x51); + if (rc < 0) + return rc; + + /* Check if data is available */ + if (!(rc & 0x01)) { + dev_info(&state->i2c->dev, + "%s: MER measures aren't available yet.\n", __func__); + return -EBUSY; + } + + /* Read all layers */ + for (i = 0; i < 3; i++) { + if (!(c->isdbt_layer_enabled & (1 << i))) { + c->cnr.stat[1 + i].scale = FE_SCALE_NOT_AVAILABLE; + continue; + } + + rc = mb86a20s_writereg(state, 0x50, 0x52 + i * 3); + if (rc < 0) + return rc; + rc = mb86a20s_readreg(state, 0x51); + if (rc < 0) + return rc; + mer = rc << 16; + rc = mb86a20s_writereg(state, 0x50, 0x53 + i * 3); + if (rc < 0) + return rc; + rc = mb86a20s_readreg(state, 0x51); + if (rc < 0) + return rc; + mer |= rc << 8; + rc = mb86a20s_writereg(state, 0x50, 0x54 + i * 3); + if (rc < 0) + return rc; + rc = mb86a20s_readreg(state, 0x51); + if (rc < 0) + return rc; + mer |= rc; + + switch (c->layer[i].modulation) { + case DQPSK: + case QPSK: + segs = cnr_qpsk_table; + segs_len = ARRAY_SIZE(cnr_qpsk_table); + break; + case QAM_16: + segs = cnr_16qam_table; + segs_len = ARRAY_SIZE(cnr_16qam_table); + break; + default: + case QAM_64: + segs = cnr_64qam_table; + segs_len = ARRAY_SIZE(cnr_64qam_table); + break; + } + cnr = interpolate_value(mer, segs, segs_len); + + c->cnr.stat[1 + i].scale = FE_SCALE_DECIBEL; + c->cnr.stat[1 + i].svalue = cnr; + + dev_dbg(&state->i2c->dev, + "%s: CNR for layer %c is %d.%03d dB (MER = %d).\n", + __func__, 'A' + i, cnr / 1000, cnr % 1000, mer); + + } + + /* Start a new MER measurement */ + /* MER counter reset */ + rc = mb86a20s_writereg(state, 0x50, 0x50); + if (rc < 0) + return rc; + rc = mb86a20s_readreg(state, 0x51); + if (rc < 0) + return rc; + val = rc; + + rc = mb86a20s_writereg(state, 0x51, val | 0x01); + if (rc < 0) + return rc; + rc = mb86a20s_writereg(state, 0x51, val & 0x06); + if (rc < 0) + return rc; + + return 0; +} + static void mb86a20s_stats_not_ready(struct dvb_frontend *fe) { struct mb86a20s_state *state = fe->demodulator_priv; @@ -934,7 +1260,13 @@ static int mb86a20s_get_stats(struct dvb_frontend *fe) u32 t_pre_bit_error = 0, t_pre_bit_count = 0; int active_layers = 0, ber_layers = 0; + dev_dbg(&state->i2c->dev, "%s called.\n", __func__); + + mb86a20s_get_main_CNR(fe); + /* Get per-layer stats */ + mb86a20s_get_per_layer_CNR(fe); + for (i = 0; i < 3; i++) { if (c->isdbt_layer_enabled & (1 << i)) { /* Layer is active and has rc segments */ -- cgit v1.2.3-55-g7522