From 149d518ad0fd0d566d4859a4d3f280ee33de8ed7 Mon Sep 17 00:00:00 2001 From: Mauro Carvalho Chehab Date: Tue, 22 Jan 2013 12:30:07 -0300 Subject: [PATCH] [media] mb86a20s: add BER measurement Add the methods to read bit error/bit count measurements from mb86a20s. On ISDB-T devices, those reads are done per layer. However, as userspace applications may not be aware of that, add a global measure that will sum the bit errors and bit counts for each layer, storing them into a global value. Reviewed-by: Antti Palosaari Signed-off-by: Mauro Carvalho Chehab --- drivers/media/dvb-frontends/mb86a20s.c | 183 ++++++++++++++++++++++++- 1 file changed, 179 insertions(+), 4 deletions(-) diff --git a/drivers/media/dvb-frontends/mb86a20s.c b/drivers/media/dvb-frontends/mb86a20s.c index d7668e6292a0..354ea664b713 100644 --- a/drivers/media/dvb-frontends/mb86a20s.c +++ b/drivers/media/dvb-frontends/mb86a20s.c @@ -650,10 +650,95 @@ static int mb86a20s_reset_counters(struct dvb_frontend *fe) if (rc < 0) goto err; + goto ok; err: + dev_err(&state->i2c->dev, + "%s: Can't reset FE statistics (error %d).\n", + __func__, rc); +ok: return rc; } +static int mb86a20s_get_ber_before_vterbi(struct dvb_frontend *fe, + unsigned layer, + u32 *error, u32 *count) +{ + struct mb86a20s_state *state = fe->demodulator_priv; + int rc; + + dev_dbg(&state->i2c->dev, "%s called.\n", __func__); + + if (layer >= 3) + return -EINVAL; + + /* Check if the BER measures are already available */ + rc = mb86a20s_readreg(state, 0x54); + if (rc < 0) + return rc; + + /* Check if data is available for that layer */ + if (!(rc & (1 << layer))) { + dev_dbg(&state->i2c->dev, + "%s: BER for layer %c is not available yet.\n", + __func__, 'A' + layer); + return -EBUSY; + } + + /* Read Bit Error Count */ + rc = mb86a20s_readreg(state, 0x55 + layer * 3); + if (rc < 0) + return rc; + *error = rc << 16; + rc = mb86a20s_readreg(state, 0x56 + layer * 3); + if (rc < 0) + return rc; + *error |= rc << 8; + rc = mb86a20s_readreg(state, 0x57 + layer * 3); + if (rc < 0) + return rc; + *error |= rc; + + dev_dbg(&state->i2c->dev, + "%s: bit error before Viterbi for layer %c: %d.\n", + __func__, 'A' + layer, *error); + + /* Read Bit Count */ + rc = mb86a20s_writereg(state, 0x50, 0xa7 + layer * 3); + if (rc < 0) + return rc; + rc = mb86a20s_readreg(state, 0x51); + if (rc < 0) + return rc; + *count = rc << 16; + rc = mb86a20s_writereg(state, 0x50, 0xa8 + layer * 3); + if (rc < 0) + return rc; + rc = mb86a20s_readreg(state, 0x51); + if (rc < 0) + return rc; + *count |= rc << 8; + rc = mb86a20s_writereg(state, 0x50, 0xa9 + layer * 3); + if (rc < 0) + return rc; + rc = mb86a20s_readreg(state, 0x51); + if (rc < 0) + return rc; + *count |= rc; + + dev_dbg(&state->i2c->dev, + "%s: bit count before Viterbi for layer %c: %d.\n", + __func__, 'A' + layer, *count); + + + /* Reset counter to collect new data */ + rc = mb86a20s_writereg(state, 0x53, 0x07 & ~(1 << layer)); + if (rc < 0) + return rc; + rc = mb86a20s_writereg(state, 0x53, 0x07); + + return 0; +} + static void mb86a20s_stats_not_ready(struct dvb_frontend *fe) { struct mb86a20s_state *state = fe->demodulator_priv; @@ -688,6 +773,72 @@ static void mb86a20s_stats_not_ready(struct dvb_frontend *fe) } } +static int mb86a20s_get_stats(struct dvb_frontend *fe) +{ + struct mb86a20s_state *state = fe->demodulator_priv; + struct dtv_frontend_properties *c = &fe->dtv_property_cache; + int rc = 0, i; + u32 bit_error = 0, bit_count = 0; + u32 t_pre_bit_error = 0, t_pre_bit_count = 0; + int active_layers = 0, ber_layers = 0; + + /* Get per-layer stats */ + for (i = 0; i < 3; i++) { + if (c->isdbt_layer_enabled & (1 << i)) { + /* Layer is active and has rc segments */ + active_layers++; + + /* Read per-layer BER */ + /* Handle BER before vterbi */ + rc = mb86a20s_get_ber_before_vterbi(fe, i, + &bit_error, + &bit_count); + if (rc >= 0) { + c->pre_bit_error.stat[1 + i].scale = FE_SCALE_COUNTER; + c->pre_bit_error.stat[1 + i].uvalue += bit_error; + c->pre_bit_count.stat[1 + i].scale = FE_SCALE_COUNTER; + c->pre_bit_count.stat[1 + i].uvalue += bit_count; + } else if (rc != -EBUSY) { + /* + * If an I/O error happened, + * measures are now unavailable + */ + c->pre_bit_error.stat[1 + i].scale = FE_SCALE_NOT_AVAILABLE; + c->pre_bit_count.stat[1 + i].scale = FE_SCALE_NOT_AVAILABLE; + dev_err(&state->i2c->dev, + "%s: Can't get BER for layer %c (error %d).\n", + __func__, 'A' + i, rc); + } + + if (c->block_error.stat[1 + i].scale != FE_SCALE_NOT_AVAILABLE) + ber_layers++; + + /* Update total BER */ + t_pre_bit_error += c->pre_bit_error.stat[1 + i].uvalue; + t_pre_bit_count += c->pre_bit_count.stat[1 + i].uvalue; + } + } + + /* + * Start showing global count if at least one error count is + * available. + */ + if (ber_layers) { + /* + * At least one per-layer BER measure was read. We can now + * calculate the total BER + * + * Total Bit Error/Count is calculated as the sum of the + * bit errors on all active layers. + */ + c->pre_bit_error.stat[0].scale = FE_SCALE_COUNTER; + c->pre_bit_error.stat[0].uvalue = t_pre_bit_error; + c->pre_bit_count.stat[0].scale = FE_SCALE_COUNTER; + c->pre_bit_count.stat[0].uvalue = t_pre_bit_count; + } + + return rc; +} /* * The functions below are called via DVB callbacks, so they need to @@ -797,14 +948,21 @@ static int mb86a20s_read_status_and_stats(struct dvb_frontend *fe, mb86a20s_stats_not_ready(fe); mb86a20s_reset_frontend_cache(fe); } - if (rc < 0) + if (rc < 0) { + dev_err(&state->i2c->dev, + "%s: Can't read frontend lock status\n", __func__); goto error; + } /* Get signal strength */ rc = mb86a20s_read_signal_strength(fe); if (rc < 0) { + dev_err(&state->i2c->dev, + "%s: Can't reset VBER registers.\n", __func__); mb86a20s_stats_not_ready(fe); mb86a20s_reset_frontend_cache(fe); + + rc = 0; /* Status is OK */ goto error; } /* Fill signal strength */ @@ -813,15 +971,32 @@ static int mb86a20s_read_status_and_stats(struct dvb_frontend *fe, if (*status & FE_HAS_LOCK) { /* Get TMCC info*/ rc = mb86a20s_get_frontend(fe); - if (rc < 0) + if (rc < 0) { + dev_err(&state->i2c->dev, + "%s: Can't get FE TMCC data.\n", __func__); + rc = 0; /* Status is OK */ goto error; - } + } + /* Get statistics */ + rc = mb86a20s_get_stats(fe); + if (rc < 0 && rc != -EBUSY) { + dev_err(&state->i2c->dev, + "%s: Can't get FE statistics.\n", __func__); + rc = 0; + goto error; + } + rc = 0; /* Don't return EBUSY to userspace */ + } + goto ok; + +error: mb86a20s_stats_not_ready(fe); +ok: if (fe->ops.i2c_gate_ctrl) fe->ops.i2c_gate_ctrl(fe, 1); -error: + return rc; }