Lines Matching +full:re +full:- +full:tuning
1 .. SPDX-License-Identifier: GPL-2.0
4 ------------------------
9 The Digital TV Frontend kABI defines a driver-internal interface for
10 registering low-level, hardware specific driver to a hardware independent
29 .name = "foo DVB-T/T2/C driver",
70 .name = "Bar DVB-S/S2 demodulator",
91 /* Satellite-specific */
100 #) For satellite digital TV standards (DVB-S, DVB-S2, ISDB-S), the
102 standards, they're specified in Hz. Due to that, if the same frontend
124 responsible for tuning the device. It supports multiple algorithms to
129 ``DVBFE_ALGO_SW``, meaning that the dvb-core will do a zigzag when tuning,
131 then, it will do ``f`` + |delta|, ``f`` - |delta|, ``f`` + 2 x |delta|,
132 ``f`` - 2 x |delta| and so on.
141 define its own hardware-assisted algorithm. Very few hardware need to
173 :ref:`statistics <frontend-stat-properties>` meant to help tuning the device
185 struct dtv_frontend_properties *c = &state->fe.dtv_property_cache;
187 c->strength.len = 1;
188 c->strength.stat[0].scale = FE_SCALE_NOT_AVAILABLE;
192 c->strength.stat[0].scale = FE_SCALE_DECIBEL;
193 c->strength.stat[0].uvalue = strength;
195 .. [#f2] For ISDB-T, it may provide both a global statistics and a per-layer
199 - c->cnr.stat[0] for global S/N carrier ratio,
200 - c->cnr.stat[1] for Layer A S/N carrier ratio,
201 - c->cnr.stat[2] for layer B S/N carrier ratio,
202 - c->cnr.stat[3] for layer C S/N carrier ratio.
212 Signal strength (:ref:`DTV-STAT-SIGNAL-STRENGTH`)
213 - Measures the signal strength level at the analog part of the tuner or
216 - Typically obtained from the gain applied to the tuner and/or frontend
220 - As the gain is visible through the set of registers that adjust the gain,
223 - Drivers should try to make it available all the times, as these statistics
232 Carrier Signal to Noise ratio (:ref:`DTV-STAT-CNR`)
233 - Signal to Noise ratio for the main carrier.
235 - Signal to Noise measurement depends on the device. On some hardware, it is
246 Bit counts post-FEC (:ref:`DTV-STAT-POST-ERROR-BIT-COUNT` and :ref:`DTV-STAT-POST-TOTAL-BIT-COUNT`)
247 - Those counters measure the number of bits and bit errors after
251 - Due to its nature, those statistics depend on full coding lock
255 Bit counts pre-FEC (:ref:`DTV-STAT-PRE-ERROR-BIT-COUNT` and :ref:`DTV-STAT-PRE-TOTAL-BIT-COUNT`)
256 - Those counters measure the number of bits and bit errors before
260 - Not all frontends provide this kind of statistics.
262 - Due to its nature, those statistics depend on inner coding lock (e. g.
265 Block counts (:ref:`DTV-STAT-ERROR-BLOCK-COUNT` and :ref:`DTV-STAT-TOTAL-BLOCK-COUNT`)
266 - Those counters measure the number of blocks and block errors after
270 - Due to its nature, those statistics depend on full coding lock
274 .. note:: All counters should be monotonically increased as they're
281 struct foo_state *state = fe->demodulator_priv;
282 struct dtv_frontend_properties *c = &fe->dtv_property_cache;
297 if (!(fe->status & FE_HAS_CARRIER))
304 /* Check if pre-BER stats are available */
305 if (!(fe->status & FE_HAS_VITERBI))
312 /* Check if post-BER stats are available */
313 if (!(fe->status & FE_HAS_SYNC))
351 struct foo_state *state = fe->demodulator_priv;
352 struct dtv_frontend_properties *c = &fe->dtv_property_cache;
373 c->pre_bit_error.stat[0].scale = FE_SCALE_COUNTER;
374 c->pre_bit_error.stat[0].uvalue += bit_error;
375 c->pre_bit_count.stat[0].scale = FE_SCALE_COUNTER;
376 c->pre_bit_count.stat[0].uvalue += rc;
402 struct foo_state *state = fe->demodulator_priv;
403 struct dtv_frontend_properties *c = &fe->dtv_property_cache;
408 if (!time_after(jiffies, state->per_jiffies_stats))
412 state->per_jiffies_stats = jiffies + msecs_to_jiffies(1000);
426 c->pre_bit_error.stat[0].scale = FE_SCALE_COUNTER;
427 c->pre_bit_error.stat[0].uvalue += bit_error;
428 c->pre_bit_count.stat[0].scale = FE_SCALE_COUNTER;
429 c->pre_bit_count.stat[0].uvalue += bits;
434 Please notice that, on both cases, we're getting the statistics using the
445 .. kernel-doc:: include/media/dvb_frontend.h