[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 <crope@iki.fi>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
This commit is contained in:
Mauro Carvalho Chehab 2013-01-22 12:30:07 -03:00
parent 09b6d21e10
commit 149d518ad0

View File

@ -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;
}