[media] mb86a20s: improve bit error count for BER (d01a8ee3) · Commits · e / devices / android_kernel_teracube_emerald

drivers/media/dvb-frontends/mb86a20s.c

+157 −3

Original line number	Diff line number	Diff line
		@@ -31,6 +31,8 @@ struct mb86a20s_state {

		struct dvb_frontend frontend;

		u32 estimated_rate[3];

		bool need_init;
		};

		@@ -39,6 +41,8 @@ struct regdata {
		u8 data;
		};

		#define BER_SAMPLING_RATE 1 /* Seconds */

		/*
		* Initialization sequence: Use whatevere default values that PV SBTVD
		* does on its initialisation, obtained via USB snoop
		@@ -87,7 +91,7 @@ static struct regdata mb86a20s_init[] = {
		* it collects the bit error count. The bit counters are initialized
		* to 65535 here. This warrants that all of them will be quickly
		* calculated when device gets locked. As TMCC is parsed, the values
		* can be adjusted later in the driver's code.
		* will be adjusted later in the driver's code.
		*/
		{ 0x52, 0x01 }, /* Turn on BER before Viterbi */
		{ 0x50, 0xa7 }, { 0x51, 0x00 },
		@@ -485,6 +489,113 @@ static void mb86a20s_reset_frontend_cache(struct dvb_frontend *fe)
		c->isdbt_sb_segment_count = 0;
		}

		/*
		* Estimates the bit rate using the per-segment bit rate given by
		* ABNT/NBR 15601 spec (table 4).
		*/
		static u32 isdbt_rate[3][5][4] = {
		{ /* DQPSK/QPSK */
		{ 280850, 312060, 330420, 340430 }, /* 1/2 */
		{ 374470, 416080, 440560, 453910 }, /* 2/3 */
		{ 421280, 468090, 495630, 510650 }, /* 3/4 */
		{ 468090, 520100, 550700, 567390 }, /* 5/6 */
		{ 491500, 546110, 578230, 595760 }, /* 7/8 */
		}, { /* QAM16 */
		{ 561710, 624130, 660840, 680870 }, /* 1/2 */
		{ 748950, 832170, 881120, 907820 }, /* 2/3 */
		{ 842570, 936190, 991260, 1021300 }, /* 3/4 */
		{ 936190, 1040210, 1101400, 1134780 }, /* 5/6 */
		{ 983000, 1092220, 1156470, 1191520 }, /* 7/8 */
		}, { /* QAM64 */
		{ 842570, 936190, 991260, 1021300 }, /* 1/2 */
		{ 1123430, 1248260, 1321680, 1361740 }, /* 2/3 */
		{ 1263860, 1404290, 1486900, 1531950 }, /* 3/4 */
		{ 1404290, 1560320, 1652110, 1702170 }, /* 5/6 */
		{ 1474500, 1638340, 1734710, 1787280 }, /* 7/8 */
		}
		};

		static void mb86a20s_layer_bitrate(struct dvb_frontend *fe, u32 layer,
		u32 modulation, u32 fec, u32 interleaving,
		u32 segment)
		{
		struct mb86a20s_state *state = fe->demodulator_priv;
		u32 rate;
		int m, f, i;

		/*
		* If modulation/fec/interleaving is not detected, the default is
		* to consider the lowest bit rate, to avoid taking too long time
		* to get BER.
		*/
		switch (modulation) {
		case DQPSK:
		case QPSK:
		default:
		m = 0;
		break;
		case QAM_16:
		m = 1;
		break;
		case QAM_64:
		m = 2;
		break;
		}

		switch (fec) {
		default:
		case FEC_1_2:
		case FEC_AUTO:
		f = 0;
		break;
		case FEC_2_3:
		f = 1;
		break;
		case FEC_3_4:
		f = 2;
		break;
		case FEC_5_6:
		f = 3;
		break;
		case FEC_7_8:
		f = 4;
		break;
		}

		switch (interleaving) {
		default:
		case GUARD_INTERVAL_1_4:
		i = 0;
		break;
		case GUARD_INTERVAL_1_8:
		i = 1;
		break;
		case GUARD_INTERVAL_1_16:
		i = 2;
		break;
		case GUARD_INTERVAL_1_32:
		i = 3;
		break;
		}

		/* Samples BER at BER_SAMPLING_RATE seconds */
		rate = isdbt_rate[m][f][i] * segment * BER_SAMPLING_RATE;

		/* Avoids sampling too quickly or to overflow the register */
		if (rate < 256)
		rate = 256;
		else if (rate > (1 << 24) - 1)
		rate = (1 << 24) - 1;

		dev_dbg(&state->i2c->dev,
		"%s: layer %c bitrate: %d kbps; counter = %d (0x%06x)\n",
		__func__, 'A' + layer, segment * isdbt_rate[m][f][i]/1000,
		rate, rate);

		state->estimated_rate[i] = rate;
		}


		static int mb86a20s_get_frontend(struct dvb_frontend *fe)
		{
		struct mb86a20s_state *state = fe->demodulator_priv;
		@@ -514,10 +625,11 @@ static int mb86a20s_get_frontend(struct dvb_frontend *fe)
		rc = mb86a20s_get_segment_count(state, i);
		if (rc < 0)
		goto noperlayer_error;
		if (rc >= 0 && rc < 14)
		if (rc >= 0 && rc < 14) {
		c->layer[i].segment_count = rc;
		else {
		} else {
		c->layer[i].segment_count = 0;
		state->estimated_rate[i] = 0;
		continue;
		}
		c->isdbt_layer_enabled \|= 1 << i;
		@@ -539,6 +651,10 @@ static int mb86a20s_get_frontend(struct dvb_frontend *fe)
		dev_dbg(&state->i2c->dev, "%s: interleaving %d.\n",
		__func__, rc);
		c->layer[i].interleaving = rc;
		mb86a20s_layer_bitrate(fe, i, c->layer[i].modulation,
		c->layer[i].fec,
		c->layer[i].interleaving,
		c->layer[i].segment_count);
		}

		rc = mb86a20s_writereg(state, 0x6d, 0x84);
		@@ -730,6 +846,42 @@ static int mb86a20s_get_ber_before_vterbi(struct dvb_frontend *fe,
		__func__, 'A' + layer, *count);


		/*
		* As we get TMCC data from the frontend, we can better estimate the
		* BER bit counters, in order to do the BER measure during a longer
		* time. Use those data, if available, to update the bit count
		* measure.
		*/

		if (state->estimated_rate[layer]
		&& state->estimated_rate[layer] != *count) {
		dev_dbg(&state->i2c->dev,
		"%s: updating layer %c counter to %d.\n",
		__func__, 'A' + layer, state->estimated_rate[layer]);
		rc = mb86a20s_writereg(state, 0x50, 0xa7 + layer * 3);
		if (rc < 0)
		return rc;
		rc = mb86a20s_writereg(state, 0x51,
		state->estimated_rate[layer] >> 16);
		if (rc < 0)
		return rc;
		rc = mb86a20s_writereg(state, 0x50, 0xa8 + layer * 3);
		if (rc < 0)
		return rc;
		rc = mb86a20s_writereg(state, 0x51,
		state->estimated_rate[layer] >> 8);
		if (rc < 0)
		return rc;
		rc = mb86a20s_writereg(state, 0x50, 0xa9 + layer * 3);
		if (rc < 0)
		return rc;
		rc = mb86a20s_writereg(state, 0x51,
		state->estimated_rate[layer]);
		if (rc < 0)
		return rc;
		}


		/* Reset counter to collect new data */
		rc = mb86a20s_writereg(state, 0x53, 0x07 & ~(1 << layer));
		if (rc < 0)
		@@ -922,8 +1074,10 @@ static int mb86a20s_set_frontend(struct dvb_frontend *fe)

		if (fe->ops.i2c_gate_ctrl)
		fe->ops.i2c_gate_ctrl(fe, 0);

		rc = mb86a20s_writeregdata(state, mb86a20s_reset_reception);
		mb86a20s_reset_counters(fe);

		if (fe->ops.i2c_gate_ctrl)
		fe->ops.i2c_gate_ctrl(fe, 1);