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authorMauro Carvalho Chehab <mchehab@redhat.com>2013-01-16 15:12:05 -0300
committerMauro Carvalho Chehab <mchehab@redhat.com>2013-01-23 19:10:49 -0200
commit25188bd0e66f244d8111c4459f2c2f262a13d272 (patch)
treec14fb32b183e2ab6246ebe34e0531d007e4b1c24
parentd01a8ee37afdeb1a00458a79854a1672ada5c9f0 (diff)
[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 <crope@iki.fi> Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
-rw-r--r--drivers/media/dvb-frontends/mb86a20s.c336
1 files changed, 334 insertions, 2 deletions
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 */

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