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Commit 149d518a authored by Mauro Carvalho Chehab's avatar Mauro Carvalho Chehab
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[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: default avatarAntti Palosaari <crope@iki.fi>
Signed-off-by: default avatarMauro Carvalho Chehab <mchehab@redhat.com>
parent 09b6d21e

drivers/media/dvb-frontends/mb86a20s.c

+178 −3
Original line number Diff line number Diff line
@@ -650,8 +650,93 @@ 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)
@@ -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;

}