// SPDX-License-Identifier: GPL-2.0-or-later /* * Digital Audio (PCM) abstract layer * Copyright (c) by Jaroslav Kysela * Abramo Bagnara */ #include #include #include #include #include #include #include #include #include #include #include #include #include "pcm_local.h" #ifdef CONFIG_SND_PCM_XRUN_DEBUG #define CREATE_TRACE_POINTS #include "pcm_trace.h" #else #define trace_hwptr(substream, pos, in_interrupt) #define trace_xrun(substream) #define trace_hw_ptr_error(substream, reason) #define trace_applptr(substream, prev, curr) #endif static int fill_silence_frames(struct snd_pcm_substream *substream, snd_pcm_uframes_t off, snd_pcm_uframes_t frames); static inline void update_silence_vars(struct snd_pcm_runtime *runtime, snd_pcm_uframes_t ptr, snd_pcm_uframes_t new_ptr) { snd_pcm_sframes_t delta; delta = new_ptr - ptr; if (delta == 0) return; if (delta < 0) delta += runtime->boundary; if ((snd_pcm_uframes_t)delta < runtime->silence_filled) runtime->silence_filled -= delta; else runtime->silence_filled = 0; runtime->silence_start = new_ptr; } /* * fill ring buffer with silence * runtime->silence_start: starting pointer to silence area * runtime->silence_filled: size filled with silence * runtime->silence_threshold: threshold from application * runtime->silence_size: maximal size from application * * when runtime->silence_size >= runtime->boundary - fill processed area with silence immediately */ void snd_pcm_playback_silence(struct snd_pcm_substream *substream, snd_pcm_uframes_t new_hw_ptr) { struct snd_pcm_runtime *runtime = substream->runtime; snd_pcm_uframes_t frames, ofs, transfer; int err; if (runtime->silence_size < runtime->boundary) { snd_pcm_sframes_t noise_dist; snd_pcm_uframes_t appl_ptr = READ_ONCE(runtime->control->appl_ptr); update_silence_vars(runtime, runtime->silence_start, appl_ptr); /* initialization outside pointer updates */ if (new_hw_ptr == ULONG_MAX) new_hw_ptr = runtime->status->hw_ptr; /* get hw_avail with the boundary crossing */ noise_dist = appl_ptr - new_hw_ptr; if (noise_dist < 0) noise_dist += runtime->boundary; /* total noise distance */ noise_dist += runtime->silence_filled; if (noise_dist >= (snd_pcm_sframes_t) runtime->silence_threshold) return; frames = runtime->silence_threshold - noise_dist; if (frames > runtime->silence_size) frames = runtime->silence_size; } else { /* * This filling mode aims at free-running mode (used for example by dmix), * which doesn't update the application pointer. */ snd_pcm_uframes_t hw_ptr = runtime->status->hw_ptr; if (new_hw_ptr == ULONG_MAX) { /* * Initialization, fill the whole unused buffer with silence. * * Usually, this is entered while stopped, before data is queued, * so both pointers are expected to be zero. */ snd_pcm_sframes_t avail = runtime->control->appl_ptr - hw_ptr; if (avail < 0) avail += runtime->boundary; /* * In free-running mode, appl_ptr will be zero even while running, * so we end up with a huge number. There is no useful way to * handle this, so we just clear the whole buffer. */ runtime->silence_filled = avail > runtime->buffer_size ? 0 : avail; runtime->silence_start = hw_ptr; } else { /* Silence the just played area immediately */ update_silence_vars(runtime, hw_ptr, new_hw_ptr); } /* * In this mode, silence_filled actually includes the valid * sample data from the user. */ frames = runtime->buffer_size - runtime->silence_filled; } if (snd_BUG_ON(frames > runtime->buffer_size)) return; if (frames == 0) return; ofs = (runtime->silence_start + runtime->silence_filled) % runtime->buffer_size; do { transfer = ofs + frames > runtime->buffer_size ? runtime->buffer_size - ofs : frames; err = fill_silence_frames(substream, ofs, transfer); snd_BUG_ON(err < 0); runtime->silence_filled += transfer; frames -= transfer; ofs = 0; } while (frames > 0); snd_pcm_dma_buffer_sync(substream, SNDRV_DMA_SYNC_DEVICE); } #ifdef CONFIG_SND_DEBUG void snd_pcm_debug_name(struct snd_pcm_substream *substream, char *name, size_t len) { snprintf(name, len, "pcmC%dD%d%c:%d", substream->pcm->card->number, substream->pcm->device, substream->stream ? 'c' : 'p', substream->number); } EXPORT_SYMBOL(snd_pcm_debug_name); #endif #define XRUN_DEBUG_BASIC (1<<0) #define XRUN_DEBUG_STACK (1<<1) /* dump also stack */ #define XRUN_DEBUG_JIFFIESCHECK (1<<2) /* do jiffies check */ #ifdef CONFIG_SND_PCM_XRUN_DEBUG #define xrun_debug(substream, mask) \ ((substream)->pstr->xrun_debug & (mask)) #else #define xrun_debug(substream, mask) 0 #endif #define dump_stack_on_xrun(substream) do { \ if (xrun_debug(substream, XRUN_DEBUG_STACK)) \ dump_stack(); \ } while (0) /* call with stream lock held */ void __snd_pcm_xrun(struct snd_pcm_substream *substream) { struct snd_pcm_runtime *runtime = substream->runtime; trace_xrun(substream); if (runtime->tstamp_mode == SNDRV_PCM_TSTAMP_ENABLE) { struct timespec64 tstamp; snd_pcm_gettime(runtime, &tstamp); runtime->status->tstamp.tv_sec = tstamp.tv_sec; runtime->status->tstamp.tv_nsec = tstamp.tv_nsec; } snd_pcm_stop(substream, SNDRV_PCM_STATE_XRUN); if (xrun_debug(substream, XRUN_DEBUG_BASIC)) { char name[16]; snd_pcm_debug_name(substream, name, sizeof(name)); pcm_warn(substream->pcm, "XRUN: %s\n", name); dump_stack_on_xrun(substream); } #ifdef CONFIG_SND_PCM_XRUN_DEBUG substream->xrun_counter++; #endif } #ifdef CONFIG_SND_PCM_XRUN_DEBUG #define hw_ptr_error(substream, in_interrupt, reason, fmt, args...) \ do { \ trace_hw_ptr_error(substream, reason); \ if (xrun_debug(substream, XRUN_DEBUG_BASIC)) { \ pr_err_ratelimited("ALSA: PCM: [%c] " reason ": " fmt, \ (in_interrupt) ? 'Q' : 'P', ##args); \ dump_stack_on_xrun(substream); \ } \ } while (0) #else /* ! CONFIG_SND_PCM_XRUN_DEBUG */ #define hw_ptr_error(substream, fmt, args...) do { } while (0) #endif int snd_pcm_update_state(struct snd_pcm_substream *substream, struct snd_pcm_runtime *runtime) { snd_pcm_uframes_t avail; avail = snd_pcm_avail(substream); if (avail > runtime->avail_max) runtime->avail_max = avail; if (runtime->state == SNDRV_PCM_STATE_DRAINING) { if (avail >= runtime->buffer_size) { snd_pcm_drain_done(substream); return -EPIPE; } } else { if (avail >= runtime->stop_threshold) { __snd_pcm_xrun(substream); return -EPIPE; } } if (runtime->twake) { if (avail >= runtime->twake) wake_up(&runtime->tsleep); } else if (avail >= runtime->control->avail_min) wake_up(&runtime->sleep); return 0; } static void update_audio_tstamp(struct snd_pcm_substream *substream, struct timespec64 *curr_tstamp, struct timespec64 *audio_tstamp) { struct snd_pcm_runtime *runtime = substream->runtime; u64 audio_frames, audio_nsecs; struct timespec64 driver_tstamp; if (runtime->tstamp_mode != SNDRV_PCM_TSTAMP_ENABLE) return; if (!(substream->ops->get_time_info) || (runtime->audio_tstamp_report.actual_type == SNDRV_PCM_AUDIO_TSTAMP_TYPE_DEFAULT)) { /* * provide audio timestamp derived from pointer position * add delay only if requested */ audio_frames = runtime->hw_ptr_wrap + runtime->status->hw_ptr; if (runtime->audio_tstamp_config.report_delay) { if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) audio_frames -= runtime->delay; else audio_frames += runtime->delay; } audio_nsecs = div_u64(audio_frames * 1000000000LL, runtime->rate); *audio_tstamp = ns_to_timespec64(audio_nsecs); } if (runtime->status->audio_tstamp.tv_sec != audio_tstamp->tv_sec || runtime->status->audio_tstamp.tv_nsec != audio_tstamp->tv_nsec) { runtime->status->audio_tstamp.tv_sec = audio_tstamp->tv_sec; runtime->status->audio_tstamp.tv_nsec = audio_tstamp->tv_nsec; runtime->status->tstamp.tv_sec = curr_tstamp->tv_sec; runtime->status->tstamp.tv_nsec = curr_tstamp->tv_nsec; } /* * re-take a driver timestamp to let apps detect if the reference tstamp * read by low-level hardware was provided with a delay */ snd_pcm_gettime(substream->runtime, &driver_tstamp); runtime->driver_tstamp = driver_tstamp; } static int snd_pcm_update_hw_ptr0(struct snd_pcm_substream *substream, unsigned int in_interrupt) { struct snd_pcm_runtime *runtime = substream->runtime; snd_pcm_uframes_t pos; snd_pcm_uframes_t old_hw_ptr, new_hw_ptr, hw_base; snd_pcm_sframes_t hdelta, delta; unsigned long jdelta; unsigned long curr_jiffies; struct timespec64 curr_tstamp; struct timespec64 audio_tstamp; int crossed_boundary = 0; old_hw_ptr = runtime->status->hw_ptr; /* * group pointer, time and jiffies reads to allow for more * accurate correlations/corrections. * The values are stored at the end of this routine after * corrections for hw_ptr position */ pos = substream->ops->pointer(substream); curr_jiffies = jiffies; if (runtime->tstamp_mode == SNDRV_PCM_TSTAMP_ENABLE) { if ((substream->ops->get_time_info) && (runtime->audio_tstamp_config.type_requested != SNDRV_PCM_AUDIO_TSTAMP_TYPE_DEFAULT)) { substream->ops->get_time_info(substream, &curr_tstamp, &audio_tstamp, &runtime->audio_tstamp_config, &runtime->audio_tstamp_report); /* re-test in case tstamp type is not supported in hardware and was demoted to DEFAULT */ if (runtime->audio_tstamp_report.actual_type == SNDRV_PCM_AUDIO_TSTAMP_TYPE_DEFAULT) snd_pcm_gettime(runtime, &curr_tstamp); } else snd_pcm_gettime(runtime, &curr_tstamp); } if (pos == SNDRV_PCM_POS_XRUN) { __snd_pcm_xrun(substream); return -EPIPE; } if (pos >= runtime->buffer_size) { if (printk_ratelimit()) { char name[16]; snd_pcm_debug_name(substream, name, sizeof(name)); pcm_err(substream->pcm, "invalid position: %s, pos = %ld, buffer size = %ld, period size = %ld\n", name, pos, runtime->buffer_size, runtime->period_size); } pos = 0; } pos -= pos % runtime->min_align; trace_hwptr(substream, pos, in_interrupt); hw_base = runtime->hw_ptr_base; new_hw_ptr = hw_base + pos; if (in_interrupt) { /* we know that one period was processed */ /* delta = "expected next hw_ptr" for in_interrupt != 0 */ delta = runtime->hw_ptr_interrupt + runtime->period_size; if (delta > new_hw_ptr) { /* check for double acknowledged interrupts */ hdelta = curr_jiffies - runtime->hw_ptr_jiffies; if (hdelta > runtime->hw_ptr_buffer_jiffies/2 + 1) { hw_base += runtime->buffer_size; if (hw_base >= runtime->boundary) { hw_base = 0; crossed_boundary++; } new_hw_ptr = hw_base + pos; goto __delta; } } } /* new_hw_ptr might be lower than old_hw_ptr in case when */ /* pointer crosses the end of the ring buffer */ if (new_hw_ptr < old_hw_ptr) { hw_base += runtime->buffer_size; if (hw_base >= runtime->boundary) { hw_base = 0; crossed_boundary++; } new_hw_ptr = hw_base + pos; } __delta: delta = new_hw_ptr - old_hw_ptr; if (delta < 0) delta += runtime->boundary; if (runtime->no_period_wakeup) { snd_pcm_sframes_t xrun_threshold; /* * Without regular period interrupts, we have to check * the elapsed time to detect xruns. */ jdelta = curr_jiffies - runtime->hw_ptr_jiffies; if (jdelta < runtime->hw_ptr_buffer_jiffies / 2) goto no_delta_check; hdelta = jdelta - delta * HZ / runtime->rate; xrun_threshold = runtime->hw_ptr_buffer_jiffies / 2 + 1; while (hdelta > xrun_threshold) { delta += runtime->buffer_size; hw_base += runtime->buffer_size; if (hw_base >= runtime->boundary) { hw_base = 0; crossed_boundary++; } new_hw_ptr = hw_base + pos; hdelta -= runtime->hw_ptr_buffer_jiffies; } goto no_delta_check; } /* something must be really wrong */ if (delta >= runtime->buffer_size + runtime->period_size) { hw_ptr_error(substream, in_interrupt, "Unexpected hw_ptr", "(stream=%i, pos=%ld, new_hw_ptr=%ld, old_hw_ptr=%ld)\n", substream->stream, (long)pos, (long)new_hw_ptr, (long)old_hw_ptr); return 0; } /* Do jiffies check only in xrun_debug mode */ if (!xrun_debug(substream, XRUN_DEBUG_JIFFIESCHECK)) goto no_jiffies_check; /* Skip the jiffies check for hardwares with BATCH flag. * Such hardware usually just increases the position at each IRQ, * thus it can't give any strange position. */ if (runtime->hw.info & SNDRV_PCM_INFO_BATCH) goto no_jiffies_check; hdelta = delta; if (hdelta < runtime->delay) goto no_jiffies_check; hdelta -= runtime->delay; jdelta = curr_jiffies - runtime->hw_ptr_jiffies; if (((hdelta * HZ) / runtime->rate) > jdelta + HZ/100) { delta = jdelta / (((runtime->period_size * HZ) / runtime->rate) + HZ/100); /* move new_hw_ptr according jiffies not pos variable */ new_hw_ptr = old_hw_ptr; hw_base = delta; /* use loop to avoid checks for delta overflows */ /* the delta value is small or zero in most cases */ while (delta > 0) { new_hw_ptr += runtime->period_size; if (new_hw_ptr >= runtime->boundary) { new_hw_ptr -= runtime->boundary; crossed_boundary--; } delta--; } /* align hw_base to buffer_size */ hw_ptr_error(substream, in_interrupt, "hw_ptr skipping", "(pos=%ld, delta=%ld, period=%ld, jdelta=%lu/%lu/%lu, hw_ptr=%ld/%ld)\n", (long)pos, (long)hdelta, (long)runtime->period_size, jdelta, ((hdelta * HZ) / runtime->rate), hw_base, (unsigned long)old_hw_ptr, (unsigned long)new_hw_ptr); /* reset values to proper state */ delta = 0; hw_base = new_hw_ptr - (new_hw_ptr % runtime->buffer_size); } no_jiffies_check: if (delta > runtime->period_size + runtime->period_size / 2) { hw_ptr_error(substream, in_interrupt, "Lost interrupts?", "(stream=%i, delta=%ld, new_hw_ptr=%ld, old_hw_ptr=%ld)\n", substream->stream, (long)delta, (long)new_hw_ptr, (long)old_hw_ptr); } no_delta_check: if (runtime->status->hw_ptr == new_hw_ptr) { runtime->hw_ptr_jiffies = curr_jiffies; update_audio_tstamp(substream, &curr_tstamp, &audio_tstamp); return 0; } if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK && runtime->silence_size > 0) snd_pcm_playback_silence(substream, new_hw_ptr); if (in_interrupt) { delta = new_hw_ptr - runtime->hw_ptr_interrupt; if (delta < 0) delta += runtime->boundary; delta -= (snd_pcm_uframes_t)delta % runtime->period_size; runtime->hw_ptr_interrupt += delta; if (runtime->hw_ptr_interrupt >= runtime->boundary) runtime->hw_ptr_interrupt -= runtime->boundary; } runtime->hw_ptr_base = hw_base; runtime->status->hw_ptr = new_hw_ptr; runtime->hw_ptr_jiffies = curr_jiffies; if (crossed_boundary) { snd_BUG_ON(crossed_boundary != 1); runtime->hw_ptr_wrap += runtime->boundary; } update_audio_tstamp(substream, &curr_tstamp, &audio_tstamp); return snd_pcm_update_state(substream, runtime); } /* CAUTION: call it with irq disabled */ int snd_pcm_update_hw_ptr(struct snd_pcm_substream *substream) { return snd_pcm_update_hw_ptr0(substream, 0); } /** * snd_pcm_set_ops - set the PCM operators * @pcm: the pcm instance * @direction: stream direction, SNDRV_PCM_STREAM_XXX * @ops: the operator table * * Sets the given PCM operators to the pcm instance. */ void snd_pcm_set_ops(struct snd_pcm *pcm, int direction, const struct snd_pcm_ops *ops) { struct snd_pcm_str *stream = &pcm->streams[direction]; struct snd_pcm_substream *substream; for (substream = stream->substream; substream != NULL; substream = substream->next) substream->ops = ops; } EXPORT_SYMBOL(snd_pcm_set_ops); /** * snd_pcm_set_sync_per_card - set the PCM sync id with card number * @substream: the pcm substream * @params: modified hardware parameters * @id: identifier (max 12 bytes) * @len: identifier length (max 12 bytes) * * Sets the PCM sync identifier for the card with zero padding. * * User space or any user should use this 16-byte identifier for a comparison only * to check if two IDs are similar or different. Special case is the identifier * containing only zeros. Interpretation for this combination is - empty (not set). * The contents of the identifier should not be interpreted in any other way. * * The synchronization ID must be unique per clock source (usually one sound card, * but multiple soundcard may use one PCM word clock source which means that they * are fully synchronized). * * This routine composes this ID using card number in first four bytes and * 12-byte additional ID. When other ID composition is used (e.g. for multiple * sound cards), make sure that the composition does not clash with this * composition scheme. */ void snd_pcm_set_sync_per_card(struct snd_pcm_substream *substream, struct snd_pcm_hw_params *params, const unsigned char *id, unsigned int len) { *(__u32 *)params->sync = cpu_to_le32(substream->pcm->card->number); len = min(12, len); memcpy(params->sync + 4, id, len); memset(params->sync + 4 + len, 0, 12 - len); } EXPORT_SYMBOL_GPL(snd_pcm_set_sync_per_card); /* * Standard ioctl routine */ static inline unsigned int div32(unsigned int a, unsigned int b, unsigned int *r) { if (b == 0) { *r = 0; return UINT_MAX; } *r = a % b; return a / b; } static inline unsigned int div_down(unsigned int a, unsigned int b) { if (b == 0) return UINT_MAX; return a / b; } static inline unsigned int div_up(unsigned int a, unsigned int b) { unsigned int r; unsigned int q; if (b == 0) return UINT_MAX; q = div32(a, b, &r); if (r) ++q; return q; } static inline unsigned int mul(unsigned int a, unsigned int b) { if (a == 0) return 0; if (div_down(UINT_MAX, a) < b) return UINT_MAX; return a * b; } static inline unsigned int muldiv32(unsigned int a, unsigned int b, unsigned int c, unsigned int *r) { u_int64_t n = (u_int64_t) a * b; if (c == 0) { *r = 0; return UINT_MAX; } n = div_u64_rem(n, c, r); if (n >= UINT_MAX) { *r = 0; return UINT_MAX; } return n; } /** * snd_interval_refine - refine the interval value of configurator * @i: the interval value to refine * @v: the interval value to refer to * * Refines the interval value with the reference value. * The interval is changed to the range satisfying both intervals. * The interval status (min, max, integer, etc.) are evaluated. * * Return: Positive if the value is changed, zero if it's not changed, or a * negative error code. */ int snd_interval_refine(struct snd_interval *i, const struct snd_interval *v) { int changed = 0; if (snd_BUG_ON(snd_interval_empty(i))) return -EINVAL; if (i->min < v->min) { i->min = v->min; i->openmin = v->openmin; changed = 1; } else if (i->min == v->min && !i->openmin && v->openmin) { i->openmin = 1; changed = 1; } if (i->max > v->max) { i->max = v->max; i->openmax = v->openmax; changed = 1; } else if (i->max == v->max && !i->openmax && v->openmax) { i->openmax = 1; changed = 1; } if (!i->integer && v->integer) { i->integer = 1; changed = 1; } if (i->integer) { if (i->openmin) { i->min++; i->openmin = 0; } if (i->openmax) { i->max--; i->openmax = 0; } } else if (!i->openmin && !i->openmax && i->min == i->max) i->integer = 1; if (snd_interval_checkempty(i)) { snd_interval_none(i); return -EINVAL; } return changed; } EXPORT_SYMBOL(snd_interval_refine); static int snd_interval_refine_first(struct snd_interval *i) { const unsigned int last_max = i->max; if (snd_BUG_ON(snd_interval_empty(i))) return -EINVAL; if (snd_interval_single(i)) return 0; i->max = i->min; if (i->openmin) i->max++; /* only exclude max value if also excluded before refine */ i->openmax = (i->openmax && i->max >= last_max); return 1; } static int snd_interval_refine_last(struct snd_interval *i) { const unsigned int last_min = i->min; if (snd_BUG_ON(snd_interval_empty(i))) return -EINVAL; if (snd_interval_single(i)) return 0; i->min = i->max; if (i->openmax) i->min--; /* only exclude min value if also excluded before refine */ i->openmin = (i->openmin && i->min <= last_min); return 1; } void snd_interval_mul(const struct snd_interval *a, const struct snd_interval *b, struct snd_interval *c) { if (a->empty || b->empty) { snd_interval_none(c); return; } c->empty = 0; c->min = mul(a->min, b->min); c->openmin = (a->openmin || b->openmin); c->max = mul(a->max, b->max); c->openmax = (a->openmax || b->openmax); c->integer = (a->integer && b->integer); } /** * snd_interval_div - refine the interval value with division * @a: dividend * @b: divisor * @c: quotient * * c = a / b * * Returns non-zero if the value is changed, zero if not changed. */ void snd_interval_div(const struct snd_interval *a, const struct snd_interval *b, struct snd_interval *c) { unsigned int r; if (a->empty || b->empty) { snd_interval_none(c); return; } c->empty = 0; c->min = div32(a->min, b->max, &r); c->openmin = (r || a->openmin || b->openmax); if (b->min > 0) { c->max = div32(a->max, b->min, &r); if (r) { c->max++; c->openmax = 1; } else c->openmax = (a->openmax || b->openmin); } else { c->max = UINT_MAX; c->openmax = 0; } c->integer = 0; } /** * snd_interval_muldivk - refine the interval value * @a: dividend 1 * @b: dividend 2 * @k: divisor (as integer) * @c: result * * c = a * b / k * * Returns non-zero if the value is changed, zero if not changed. */ void snd_interval_muldivk(const struct snd_interval *a, const struct snd_interval *b, unsigned int k, struct snd_interval *c) { unsigned int r; if (a->empty || b->empty) { snd_interval_none(c); return; } c->empty = 0; c->min = muldiv32(a->min, b->min, k, &r); c->openmin = (r || a->openmin || b->openmin); c->max = muldiv32(a->max, b->max, k, &r); if (r) { c->max++; c->openmax = 1; } else c->openmax = (a->openmax || b->openmax); c->integer = 0; } /** * snd_interval_mulkdiv - refine the interval value * @a: dividend 1 * @k: dividend 2 (as integer) * @b: divisor * @c: result * * c = a * k / b * * Returns non-zero if the value is changed, zero if not changed. */ void snd_interval_mulkdiv(const struct snd_interval *a, unsigned int k, const struct snd_interval *b, struct snd_interval *c) { unsigned int r; if (a->empty || b->empty) { snd_interval_none(c); return; } c->empty = 0; c->min = muldiv32(a->min, k, b->max, &r); c->openmin = (r || a->openmin || b->openmax); if (b->min > 0) { c->max = muldiv32(a->max, k, b->min, &r); if (r) { c->max++; c->openmax = 1; } else c->openmax = (a->openmax || b->openmin); } else { c->max = UINT_MAX; c->openmax = 0; } c->integer = 0; } /* ---- */ /** * snd_interval_ratnum - refine the interval value * @i: interval to refine * @rats_count: number of ratnum_t * @rats: ratnum_t array * @nump: pointer to store the resultant numerator * @denp: pointer to store the resultant denominator * * Return: Positive if the value is changed, zero if it's not changed, or a * negative error code. */ int snd_interval_ratnum(struct snd_interval *i, unsigned int rats_count, const struct snd_ratnum *rats, unsigned int *nump, unsigned int *denp) { unsigned int best_num, best_den; int best_diff; unsigned int k; struct snd_interval t; int err; unsigned int result_num, result_den; int result_diff; best_num = best_den = best_diff = 0; for (k = 0; k < rats_count; ++k) { unsigned int num = rats[k].num; unsigned int den; unsigned int q = i->min; int diff; if (q == 0) q = 1; den = div_up(num, q); if (den < rats[k].den_min) continue; if (den > rats[k].den_max) den = rats[k].den_max; else { unsigned int r; r = (den - rats[k].den_min) % rats[k].den_step; if (r != 0) den -= r; } diff = num - q * den; if (diff < 0) diff = -diff; if (best_num == 0 || diff * best_den < best_diff * den) { best_diff = diff; best_den = den; best_num = num; } } if (best_den == 0) { i->empty = 1; return -EINVAL; } t.min = div_down(best_num, best_den); t.openmin = !!(best_num % best_den); result_num = best_num; result_diff = best_diff; result_den = best_den; best_num = best_den = best_diff = 0; for (k = 0; k < rats_count; ++k) { unsigned int num = rats[k].num; unsigned int den; unsigned int q = i->max; int diff; if (q == 0) { i->empty = 1; return -EINVAL; } den = div_down(num, q); if (den > rats[k].den_max) continue; if (den < rats[k].den_min) den = rats[k].den_min; else { unsigned int r; r = (den - rats[k].den_min) % rats[k].den_step; if (r != 0) den += rats[k].den_step - r; } diff = q * den - num; if (diff < 0) diff = -diff; if (best_num == 0 || diff * best_den < best_diff * den) { best_diff = diff; best_den = den; best_num = num; } } if (best_den == 0) { i->empty = 1; return -EINVAL; } t.max = div_up(best_num, best_den); t.openmax = !!(best_num % best_den); t.integer = 0; err = snd_interval_refine(i, &t); if (err < 0) return err; if (snd_interval_single(i)) { if (best_diff * result_den < result_diff * best_den) { result_num = best_num; result_den = best_den; } if (nump) *nump = result_num; if (denp) *denp = result_den; } return err; } EXPORT_SYMBOL(snd_interval_ratnum); /** * snd_interval_ratden - refine the interval value * @i: interval to refine * @rats_count: number of struct ratden * @rats: struct ratden array * @nump: pointer to store the resultant numerator * @denp: pointer to store the resultant denominator * * Return: Positive if the value is changed, zero if it's not changed, or a * negative error code. */ static int snd_interval_ratden(struct snd_interval *i, unsigned int rats_count, const struct snd_ratden *rats, unsigned int *nump, unsigned int *denp) { unsigned int best_num, best_diff, best_den; unsigned int k; struct snd_interval t; int err; best_num = best_den = best_diff = 0; for (k = 0; k < rats_count; ++k) { unsigned int num; unsigned int den = rats[k].den; unsigned int q = i->min; int diff; num = mul(q, den); if (num > rats[k].num_max) continue; if (num < rats[k].num_min) num = rats[k].num_max; else { unsigned int r; r = (num - rats[k].num_min) % rats[k].num_step; if (r != 0) num += rats[k].num_step - r; } diff = num - q * den; if (best_num == 0 || diff * best_den < best_diff * den) { best_diff = diff; best_den = den; best_num = num; } } if (best_den == 0) { i->empty = 1; return -EINVAL; } t.min = div_down(best_num, best_den); t.openmin = !!(best_num % best_den); best_num = best_den = best_diff = 0; for (k = 0; k < rats_count; ++k) { unsigned int num; unsigned int den = rats[k].den; unsigned int q = i->max; int diff; num = mul(q, den); if (num < rats[k].num_min) continue; if (num > rats[k].num_max) num = rats[k].num_max; else { unsigned int r; r = (num - rats[k].num_min) % rats[k].num_step; if (r != 0) num -= r; } diff = q * den - num; if (best_num == 0 || diff * best_den < best_diff * den) { best_diff = diff; best_den = den; best_num = num; } } if (best_den == 0) { i->empty = 1; return -EINVAL; } t.max = div_up(best_num, best_den); t.openmax = !!(best_num % best_den); t.integer = 0; err = snd_interval_refine(i, &t); if (err < 0) return err; if (snd_interval_single(i)) { if (nump) *nump = best_num; if (denp) *denp = best_den; } return err; } /** * snd_interval_list - refine the interval value from the list * @i: the interval value to refine * @count: the number of elements in the list * @list: the value list * @mask: the bit-mask to evaluate * * Refines the interval value from the list. * When mask is non-zero, only the elements corresponding to bit 1 are * evaluated. * * Return: Positive if the value is changed, zero if it's not changed, or a * negative error code. */ int snd_interval_list(struct snd_interval *i, unsigned int count, const unsigned int *list, unsigned int mask) { unsigned int k; struct snd_interval list_range; if (!count) { i->empty = 1; return -EINVAL; } snd_interval_any(&list_range); list_range.min = UINT_MAX; list_range.max = 0; for (k = 0; k < count; k++) { if (mask && !(mask & (1 << k))) continue; if (!snd_interval_test(i, list[k])) continue; list_range.min = min(list_range.min, list[k]); list_range.max = max(list_range.max, list[k]); } return snd_interval_refine(i, &list_range); } EXPORT_SYMBOL(snd_interval_list); /** * snd_interval_ranges - refine the interval value from the list of ranges * @i: the interval value to refine * @count: the number of elements in the list of ranges * @ranges: the ranges list * @mask: the bit-mask to evaluate * * Refines the interval value from the list of ranges. * When mask is non-zero, only the elements corresponding to bit 1 are * evaluated. * * Return: Positive if the value is changed, zero if it's not changed, or a * negative error code. */ int snd_interval_ranges(struct snd_interval *i, unsigned int count, const struct snd_interval *ranges, unsigned int mask) { unsigned int k; struct snd_interval range_union; struct snd_interval range; if (!count) { snd_interval_none(i); return -EINVAL; } snd_interval_any(&range_union); range_union.min = UINT_MAX; range_union.max = 0; for (k = 0; k < count; k++) { if (mask && !(mask & (1 << k))) continue; snd_interval_copy(&range, &ranges[k]); if (snd_interval_refine(&range, i) < 0) continue; if (snd_interval_empty(&range)) continue; if (range.min < range_union.min) { range_union.min = range.min; range_union.openmin = 1; } if (range.min == range_union.min && !range.openmin) range_union.openmin = 0; if (range.max > range_union.max) { range_union.max = range.max; range_union.openmax = 1; } if (range.max == range_union.max && !range.openmax) range_union.openmax = 0; } return snd_interval_refine(i, &range_union); } EXPORT_SYMBOL(snd_interval_ranges); static int snd_interval_step(struct snd_interval *i, unsigned int step) { unsigned int n; int changed = 0; n = i->min % step; if (n != 0 || i->openmin) { i->min += step - n; i->openmin = 0; changed = 1; } n = i->max % step; if (n != 0 || i->openmax) { i->max -= n; i->openmax = 0; changed = 1; } if (snd_interval_checkempty(i)) { i->empty = 1; return -EINVAL; } return changed; } /* Info constraints helpers */ /** * snd_pcm_hw_rule_add - add the hw-constraint rule * @runtime: the pcm runtime instance * @cond: condition bits * @var: the variable to evaluate * @func: the evaluation function * @private: the private data pointer passed to function * @dep: the dependent variables * * Return: Zero if successful, or a negative error code on failure. */ int snd_pcm_hw_rule_add(struct snd_pcm_runtime *runtime, unsigned int cond, int var, snd_pcm_hw_rule_func_t func, void *private, int dep, ...) { struct snd_pcm_hw_constraints *constrs = &runtime->hw_constraints; struct snd_pcm_hw_rule *c; unsigned int k; va_list args; va_start(args, dep); if (constrs->rules_num >= constrs->rules_all) { struct snd_pcm_hw_rule *new; unsigned int new_rules = constrs->rules_all + 16; new = krealloc_array(constrs->rules, new_rules, sizeof(*c), GFP_KERNEL); if (!new) { va_end(args); return -ENOMEM; } constrs->rules = new; constrs->rules_all = new_rules; } c = &constrs->rules[constrs->rules_num]; c->cond = cond; c->func = func; c->var = var; c->private = private; k = 0; while (1) { if (snd_BUG_ON(k >= ARRAY_SIZE(c->deps))) { va_end(args); return -EINVAL; } c->deps[k++] = dep; if (dep < 0) break; dep = va_arg(args, int); } constrs->rules_num++; va_end(args); return 0; } EXPORT_SYMBOL(snd_pcm_hw_rule_add); /** * snd_pcm_hw_constraint_mask - apply the given bitmap mask constraint * @runtime: PCM runtime instance * @var: hw_params variable to apply the mask * @mask: the bitmap mask * * Apply the constraint of the given bitmap mask to a 32-bit mask parameter. * * Return: Zero if successful, or a negative error code on failure. */ int snd_pcm_hw_constraint_mask(struct snd_pcm_runtime *runtime, snd_pcm_hw_param_t var, u_int32_t mask) { struct snd_pcm_hw_constraints *constrs = &runtime->hw_constraints; struct snd_mask *maskp = constrs_mask(constrs, var); *maskp->bits &= mask; memset(maskp->bits + 1, 0, (SNDRV_MASK_MAX-32) / 8); /* clear rest */ if (*maskp->bits == 0) return -EINVAL; return 0; } /** * snd_pcm_hw_constraint_mask64 - apply the given bitmap mask constraint * @runtime: PCM runtime instance * @var: hw_params variable to apply the mask * @mask: the 64bit bitmap mask * * Apply the constraint of the given bitmap mask to a 64-bit mask parameter. * * Return: Zero if successful, or a negative error code on failure. */ int snd_pcm_hw_constraint_mask64(struct snd_pcm_runtime *runtime, snd_pcm_hw_param_t var, u_int64_t mask) { struct snd_pcm_hw_constraints *constrs = &runtime->hw_constraints; struct snd_mask *maskp = constrs_mask(constrs, var); maskp->bits[0] &= (u_int32_t)mask; maskp->bits[1] &= (u_int32_t)(mask >> 32); memset(maskp->bits + 2, 0, (SNDRV_MASK_MAX-64) / 8); /* clear rest */ if (! maskp->bits[0] && ! maskp->bits[1]) return -EINVAL; return 0; } EXPORT_SYMBOL(snd_pcm_hw_constraint_mask64); /** * snd_pcm_hw_constraint_integer - apply an integer constraint to an interval * @runtime: PCM runtime instance * @var: hw_params variable to apply the integer constraint * * Apply the constraint of integer to an interval parameter. * * Return: Positive if the value is changed, zero if it's not changed, or a * negative error code. */ int snd_pcm_hw_constraint_integer(struct snd_pcm_runtime *runtime, snd_pcm_hw_param_t var) { struct snd_pcm_hw_constraints *constrs = &runtime->hw_constraints; return snd_interval_setinteger(constrs_interval(constrs, var)); } EXPORT_SYMBOL(snd_pcm_hw_constraint_integer); /** * snd_pcm_hw_constraint_minmax - apply a min/max range constraint to an interval * @runtime: PCM runtime instance * @var: hw_params variable to apply the range * @min: the minimal value * @max: the maximal value * * Apply the min/max range constraint to an interval parameter. * * Return: Positive if the value is changed, zero if it's not changed, or a * negative error code. */ int snd_pcm_hw_constraint_minmax(struct snd_pcm_runtime *runtime, snd_pcm_hw_param_t var, unsigned int min, unsigned int max) { struct snd_pcm_hw_constraints *constrs = &runtime->hw_constraints; struct snd_interval t; t.min = min; t.max = max; t.openmin = t.openmax = 0; t.integer = 0; return snd_interval_refine(constrs_interval(constrs, var), &t); } EXPORT_SYMBOL(snd_pcm_hw_constraint_minmax); static int snd_pcm_hw_rule_list(struct snd_pcm_hw_params *params, struct snd_pcm_hw_rule *rule) { struct snd_pcm_hw_constraint_list *list = rule->private; return snd_interval_list(hw_param_interval(params, rule->var), list->count, list->list, list->mask); } /** * snd_pcm_hw_constraint_list - apply a list of constraints to a parameter * @runtime: PCM runtime instance * @cond: condition bits * @var: hw_params variable to apply the list constraint * @l: list * * Apply the list of constraints to an interval parameter. * * Return: Zero if successful, or a negative error code on failure. */ int snd_pcm_hw_constraint_list(struct snd_pcm_runtime *runtime, unsigned int cond, snd_pcm_hw_param_t var, const struct snd_pcm_hw_constraint_list *l) { return snd_pcm_hw_rule_add(runtime, cond, var, snd_pcm_hw_rule_list, (void *)l, var, -1); } EXPORT_SYMBOL(snd_pcm_hw_constraint_list); static int snd_pcm_hw_rule_ranges(struct snd_pcm_hw_params *params, struct snd_pcm_hw_rule *rule) { struct snd_pcm_hw_constraint_ranges *r = rule->private; return snd_interval_ranges(hw_param_interval(params, rule->var), r->count, r->ranges, r->mask); } /** * snd_pcm_hw_constraint_ranges - apply list of range constraints to a parameter * @runtime: PCM runtime instance * @cond: condition bits * @var: hw_params variable to apply the list of range constraints * @r: ranges * * Apply the list of range constraints to an interval parameter. * * Return: Zero if successful, or a negative error code on failure. */ int snd_pcm_hw_constraint_ranges(struct snd_pcm_runtime *runtime, unsigned int cond, snd_pcm_hw_param_t var, const struct snd_pcm_hw_constraint_ranges *r) { return snd_pcm_hw_rule_add(runtime, cond, var, snd_pcm_hw_rule_ranges, (void *)r, var, -1); } EXPORT_SYMBOL(snd_pcm_hw_constraint_ranges); static int snd_pcm_hw_rule_ratnums(struct snd_pcm_hw_params *params, struct snd_pcm_hw_rule *rule) { const struct snd_pcm_hw_constraint_ratnums *r = rule->private; unsigned int num = 0, den = 0; int err; err = snd_interval_ratnum(hw_param_interval(params, rule->var), r->nrats, r->rats, &num, &den); if (err >= 0 && den && rule->var == SNDRV_PCM_HW_PARAM_RATE) { params->rate_num = num; params->rate_den = den; } return err; } /** * snd_pcm_hw_constraint_ratnums - apply ratnums constraint to a parameter * @runtime: PCM runtime instance * @cond: condition bits * @var: hw_params variable to apply the ratnums constraint * @r: struct snd_ratnums constriants * * Return: Zero if successful, or a negative error code on failure. */ int snd_pcm_hw_constraint_ratnums(struct snd_pcm_runtime *runtime, unsigned int cond, snd_pcm_hw_param_t var, const struct snd_pcm_hw_constraint_ratnums *r) { return snd_pcm_hw_rule_add(runtime, cond, var, snd_pcm_hw_rule_ratnums, (void *)r, var, -1); } EXPORT_SYMBOL(snd_pcm_hw_constraint_ratnums); static int snd_pcm_hw_rule_ratdens(struct snd_pcm_hw_params *params, struct snd_pcm_hw_rule *rule) { const struct snd_pcm_hw_constraint_ratdens *r = rule->private; unsigned int num = 0, den = 0; int err = snd_interval_ratden(hw_param_interval(params, rule->var), r->nrats, r->rats, &num, &den); if (err >= 0 && den && rule->var == SNDRV_PCM_HW_PARAM_RATE) { params->rate_num = num; params->rate_den = den; } return err; } /** * snd_pcm_hw_constraint_ratdens - apply ratdens constraint to a parameter * @runtime: PCM runtime instance * @cond: condition bits * @var: hw_params variable to apply the ratdens constraint * @r: struct snd_ratdens constriants * * Return: Zero if successful, or a negative error code on failure. */ int snd_pcm_hw_constraint_ratdens(struct snd_pcm_runtime *runtime, unsigned int cond, snd_pcm_hw_param_t var, const struct snd_pcm_hw_constraint_ratdens *r) { return snd_pcm_hw_rule_add(runtime, cond, var, snd_pcm_hw_rule_ratdens, (void *)r, var, -1); } EXPORT_SYMBOL(snd_pcm_hw_constraint_ratdens); static int snd_pcm_hw_rule_msbits(struct snd_pcm_hw_params *params, struct snd_pcm_hw_rule *rule) { unsigned int l = (unsigned long) rule->private; int width = l & 0xffff; unsigned int msbits = l >> 16; const struct snd_interval *i = hw_param_interval_c(params, SNDRV_PCM_HW_PARAM_SAMPLE_BITS); if (!snd_interval_single(i)) return 0; if ((snd_interval_value(i) == width) || (width == 0 && snd_interval_value(i) > msbits)) params->msbits = min_not_zero(params->msbits, msbits); return 0; } /** * snd_pcm_hw_constraint_msbits - add a hw constraint msbits rule * @runtime: PCM runtime instance * @cond: condition bits * @width: sample bits width * @msbits: msbits width * * This constraint will set the number of most significant bits (msbits) if a * sample format with the specified width has been select. If width is set to 0 * the msbits will be set for any sample format with a width larger than the * specified msbits. * * Return: Zero if successful, or a negative error code on failure. */ int snd_pcm_hw_constraint_msbits(struct snd_pcm_runtime *runtime, unsigned int cond, unsigned int width, unsigned int msbits) { unsigned long l = (msbits << 16) | width; return snd_pcm_hw_rule_add(runtime, cond, -1, snd_pcm_hw_rule_msbits, (void*) l, SNDRV_PCM_HW_PARAM_SAMPLE_BITS, -1); } EXPORT_SYMBOL(snd_pcm_hw_constraint_msbits); static int snd_pcm_hw_rule_step(struct snd_pcm_hw_params *params, struct snd_pcm_hw_rule *rule) { unsigned long step = (unsigned long) rule->private; return snd_interval_step(hw_param_interval(params, rule->var), step); } /** * snd_pcm_hw_constraint_step - add a hw constraint step rule * @runtime: PCM runtime instance * @cond: condition bits * @var: hw_params variable to apply the step constraint * @step: step size * * Return: Zero if successful, or a negative error code on failure. */ int snd_pcm_hw_constraint_step(struct snd_pcm_runtime *runtime, unsigned int cond, snd_pcm_hw_param_t var, unsigned long step) { return snd_pcm_hw_rule_add(runtime, cond, var, snd_pcm_hw_rule_step, (void *) step, var, -1); } EXPORT_SYMBOL(snd_pcm_hw_constraint_step); static int snd_pcm_hw_rule_pow2(struct snd_pcm_hw_params *params, struct snd_pcm_hw_rule *rule) { static const unsigned int pow2_sizes[] = { 1<<0, 1<<1, 1<<2, 1<<3, 1<<4, 1<<5, 1<<6, 1<<7, 1<<8, 1<<9, 1<<10, 1<<11, 1<<12, 1<<13, 1<<14, 1<<15, 1<<16, 1<<17, 1<<18, 1<<19, 1<<20, 1<<21, 1<<22, 1<<23, 1<<24, 1<<25, 1<<26, 1<<27, 1<<28, 1<<29, 1<<30 }; return snd_interval_list(hw_param_interval(params, rule->var), ARRAY_SIZE(pow2_sizes), pow2_sizes, 0); } /** * snd_pcm_hw_constraint_pow2 - add a hw constraint power-of-2 rule * @runtime: PCM runtime instance * @cond: condition bits * @var: hw_params variable to apply the power-of-2 constraint * * Return: Zero if successful, or a negative error code on failure. */ int snd_pcm_hw_constraint_pow2(struct snd_pcm_runtime *runtime, unsigned int cond, snd_pcm_hw_param_t var) { return snd_pcm_hw_rule_add(runtime, cond, var, snd_pcm_hw_rule_pow2, NULL, var, -1); } EXPORT_SYMBOL(snd_pcm_hw_constraint_pow2); static int snd_pcm_hw_rule_noresample_func(struct snd_pcm_hw_params *params, struct snd_pcm_hw_rule *rule) { unsigned int base_rate = (unsigned int)(uintptr_t)rule->private; struct snd_interval *rate; rate = hw_param_interval(params, SNDRV_PCM_HW_PARAM_RATE); return snd_interval_list(rate, 1, &base_rate, 0); } /** * snd_pcm_hw_rule_noresample - add a rule to allow disabling hw resampling * @runtime: PCM runtime instance * @base_rate: the rate at which the hardware does not resample * * Return: Zero if successful, or a negative error code on failure. */ int snd_pcm_hw_rule_noresample(struct snd_pcm_runtime *runtime, unsigned int base_rate) { return snd_pcm_hw_rule_add(runtime, SNDRV_PCM_HW_PARAMS_NORESAMPLE, SNDRV_PCM_HW_PARAM_RATE, snd_pcm_hw_rule_noresample_func, (void *)(uintptr_t)base_rate, SNDRV_PCM_HW_PARAM_RATE, -1); } EXPORT_SYMBOL(snd_pcm_hw_rule_noresample); static void _snd_pcm_hw_param_any(struct snd_pcm_hw_params *params, snd_pcm_hw_param_t var) { if (hw_is_mask(var)) { snd_mask_any(hw_param_mask(params, var)); params->cmask |= 1 << var; params->rmask |= 1 << var; return; } if (hw_is_interval(var)) { snd_interval_any(hw_param_interval(params, var)); params->cmask |= 1 << var; params->rmask |= 1 << var; return; } snd_BUG(); } void _snd_pcm_hw_params_any(struct snd_pcm_hw_params *params) { unsigned int k; memset(params, 0, sizeof(*params)); for (k = SNDRV_PCM_HW_PARAM_FIRST_MASK; k <= SNDRV_PCM_HW_PARAM_LAST_MASK; k++) _snd_pcm_hw_param_any(params, k); for (k = SNDRV_PCM_HW_PARAM_FIRST_INTERVAL; k <= SNDRV_PCM_HW_PARAM_LAST_INTERVAL; k++) _snd_pcm_hw_param_any(params, k); params->info = ~0U; } EXPORT_SYMBOL(_snd_pcm_hw_params_any); /** * snd_pcm_hw_param_value - return @params field @var value * @params: the hw_params instance * @var: parameter to retrieve * @dir: pointer to the direction (-1,0,1) or %NULL * * Return: The value for field @var if it's fixed in configuration space * defined by @params. -%EINVAL otherwise. */ int snd_pcm_hw_param_value(const struct snd_pcm_hw_params *params, snd_pcm_hw_param_t var, int *dir) { if (hw_is_mask(var)) { const struct snd_mask *mask = hw_param_mask_c(params, var); if (!snd_mask_single(mask)) return -EINVAL; if (dir) *dir = 0; return snd_mask_value(mask); } if (hw_is_interval(var)) { const struct snd_interval *i = hw_param_interval_c(params, var); if (!snd_interval_single(i)) return -EINVAL; if (dir) *dir = i->openmin; return snd_interval_value(i); } return -EINVAL; } EXPORT_SYMBOL(snd_pcm_hw_param_value); void _snd_pcm_hw_param_setempty(struct snd_pcm_hw_params *params, snd_pcm_hw_param_t var) { if (hw_is_mask(var)) { snd_mask_none(hw_param_mask(params, var)); params->cmask |= 1 << var; params->rmask |= 1 << var; } else if (hw_is_interval(var)) { snd_interval_none(hw_param_interval(params, var)); params->cmask |= 1 << var; params->rmask |= 1 << var; } else { snd_BUG(); } } EXPORT_SYMBOL(_snd_pcm_hw_param_setempty); static int _snd_pcm_hw_param_first(struct snd_pcm_hw_params *params, snd_pcm_hw_param_t var) { int changed; if (hw_is_mask(var)) changed = snd_mask_refine_first(hw_param_mask(params, var)); else if (hw_is_interval(var)) changed = snd_interval_refine_first(hw_param_interval(params, var)); else return -EINVAL; if (changed > 0) { params->cmask |= 1 << var; params->rmask |= 1 << var; } return changed; } /** * snd_pcm_hw_param_first - refine config space and return minimum value * @pcm: PCM instance * @params: the hw_params instance * @var: parameter to retrieve * @dir: pointer to the direction (-1,0,1) or %NULL * * Inside configuration space defined by @params remove from @var all * values > minimum. Reduce configuration space accordingly. * * Return: The minimum, or a negative error code on failure. */ int snd_pcm_hw_param_first(struct snd_pcm_substream *pcm, struct snd_pcm_hw_params *params, snd_pcm_hw_param_t var, int *dir) { int changed = _snd_pcm_hw_param_first(params, var); if (changed < 0) return changed; if (params->rmask) { int err = snd_pcm_hw_refine(pcm, params); if (err < 0) return err; } return snd_pcm_hw_param_value(params, var, dir); } EXPORT_SYMBOL(snd_pcm_hw_param_first); static int _snd_pcm_hw_param_last(struct snd_pcm_hw_params *params, snd_pcm_hw_param_t var) { int changed; if (hw_is_mask(var)) changed = snd_mask_refine_last(hw_param_mask(params, var)); else if (hw_is_interval(var)) changed = snd_interval_refine_last(hw_param_interval(params, var)); else return -EINVAL; if (changed > 0) { params->cmask |= 1 << var; params->rmask |= 1 << var; } return changed; } /** * snd_pcm_hw_param_last - refine config space and return maximum value * @pcm: PCM instance * @params: the hw_params instance * @var: parameter to retrieve * @dir: pointer to the direction (-1,0,1) or %NULL * * Inside configuration space defined by @params remove from @var all * values < maximum. Reduce configuration space accordingly. * * Return: The maximum, or a negative error code on failure. */ int snd_pcm_hw_param_last(struct snd_pcm_substream *pcm, struct snd_pcm_hw_params *params, snd_pcm_hw_param_t var, int *dir) { int changed = _snd_pcm_hw_param_last(params, var); if (changed < 0) return changed; if (params->rmask) { int err = snd_pcm_hw_refine(pcm, params); if (err < 0) return err; } return snd_pcm_hw_param_value(params, var, dir); } EXPORT_SYMBOL(snd_pcm_hw_param_last); /** * snd_pcm_hw_params_bits - Get the number of bits per the sample. * @p: hardware parameters * * Return: The number of bits per sample based on the format, * subformat and msbits the specified hw params has. */ int snd_pcm_hw_params_bits(const struct snd_pcm_hw_params *p) { snd_pcm_subformat_t subformat = params_subformat(p); snd_pcm_format_t format = params_format(p); switch (format) { case SNDRV_PCM_FORMAT_S32_LE: case SNDRV_PCM_FORMAT_U32_LE: case SNDRV_PCM_FORMAT_S32_BE: case SNDRV_PCM_FORMAT_U32_BE: switch (subformat) { case SNDRV_PCM_SUBFORMAT_MSBITS_20: return 20; case SNDRV_PCM_SUBFORMAT_MSBITS_24: return 24; case SNDRV_PCM_SUBFORMAT_MSBITS_MAX: case SNDRV_PCM_SUBFORMAT_STD: default: break; } fallthrough; default: return snd_pcm_format_width(format); } } EXPORT_SYMBOL(snd_pcm_hw_params_bits); static int snd_pcm_lib_ioctl_reset(struct snd_pcm_substream *substream, void *arg) { struct snd_pcm_runtime *runtime = substream->runtime; guard(pcm_stream_lock_irqsave)(substream); if (snd_pcm_running(substream) && snd_pcm_update_hw_ptr(substream) >= 0) runtime->status->hw_ptr %= runtime->buffer_size; else { runtime->status->hw_ptr = 0; runtime->hw_ptr_wrap = 0; } return 0; } static int snd_pcm_lib_ioctl_channel_info(struct snd_pcm_substream *substream, void *arg) { struct snd_pcm_channel_info *info = arg; struct snd_pcm_runtime *runtime = substream->runtime; int width; if (!(runtime->info & SNDRV_PCM_INFO_MMAP)) { info->offset = -1; return 0; } width = snd_pcm_format_physical_width(runtime->format); if (width < 0) return width; info->offset = 0; switch (runtime->access) { case SNDRV_PCM_ACCESS_MMAP_INTERLEAVED: case SNDRV_PCM_ACCESS_RW_INTERLEAVED: info->first = info->channel * width; info->step = runtime->channels * width; break; case SNDRV_PCM_ACCESS_MMAP_NONINTERLEAVED: case SNDRV_PCM_ACCESS_RW_NONINTERLEAVED: { size_t size = runtime->dma_bytes / runtime->channels; info->first = info->channel * size * 8; info->step = width; break; } default: snd_BUG(); break; } return 0; } static int snd_pcm_lib_ioctl_fifo_size(struct snd_pcm_substream *substream, void *arg) { struct snd_pcm_hw_params *params = arg; snd_pcm_format_t format; int channels; ssize_t frame_size; params->fifo_size = substream->runtime->hw.fifo_size; if (!(substream->runtime->hw.info & SNDRV_PCM_INFO_FIFO_IN_FRAMES)) { format = params_format(params); channels = params_channels(params); frame_size = snd_pcm_format_size(format, channels); if (frame_size > 0) params->fifo_size /= frame_size; } return 0; } static int snd_pcm_lib_ioctl_sync_id(struct snd_pcm_substream *substream, void *arg) { static const unsigned char id[12] = { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff }; if (substream->runtime->std_sync_id) snd_pcm_set_sync_per_card(substream, arg, id, sizeof(id)); return 0; } /** * snd_pcm_lib_ioctl - a generic PCM ioctl callback * @substream: the pcm substream instance * @cmd: ioctl command * @arg: ioctl argument * * Processes the generic ioctl commands for PCM. * Can be passed as the ioctl callback for PCM ops. * * Return: Zero if successful, or a negative error code on failure. */ int snd_pcm_lib_ioctl(struct snd_pcm_substream *substream, unsigned int cmd, void *arg) { switch (cmd) { case SNDRV_PCM_IOCTL1_RESET: return snd_pcm_lib_ioctl_reset(substream, arg); case SNDRV_PCM_IOCTL1_CHANNEL_INFO: return snd_pcm_lib_ioctl_channel_info(substream, arg); case SNDRV_PCM_IOCTL1_FIFO_SIZE: return snd_pcm_lib_ioctl_fifo_size(substream, arg); case SNDRV_PCM_IOCTL1_SYNC_ID: return snd_pcm_lib_ioctl_sync_id(substream, arg); } return -ENXIO; } EXPORT_SYMBOL(snd_pcm_lib_ioctl); /** * snd_pcm_period_elapsed_under_stream_lock() - update the status of runtime for the next period * under acquired lock of PCM substream. * @substream: the instance of pcm substream. * * This function is called when the batch of audio data frames as the same size as the period of * buffer is already processed in audio data transmission. * * The call of function updates the status of runtime with the latest position of audio data * transmission, checks overrun and underrun over buffer, awaken user processes from waiting for * available audio data frames, sampling audio timestamp, and performs stop or drain the PCM * substream according to configured threshold. * * The function is intended to use for the case that PCM driver operates audio data frames under * acquired lock of PCM substream; e.g. in callback of any operation of &snd_pcm_ops in process * context. In any interrupt context, it's preferrable to use ``snd_pcm_period_elapsed()`` instead * since lock of PCM substream should be acquired in advance. * * Developer should pay enough attention that some callbacks in &snd_pcm_ops are done by the call of * function: * * - .pointer - to retrieve current position of audio data transmission by frame count or XRUN state. * - .trigger - with SNDRV_PCM_TRIGGER_STOP at XRUN or DRAINING state. * - .get_time_info - to retrieve audio time stamp if needed. * * Even if more than one periods have elapsed since the last call, you have to call this only once. */ void snd_pcm_period_elapsed_under_stream_lock(struct snd_pcm_substream *substream) { struct snd_pcm_runtime *runtime; if (PCM_RUNTIME_CHECK(substream)) return; runtime = substream->runtime; if (!snd_pcm_running(substream) || snd_pcm_update_hw_ptr0(substream, 1) < 0) goto _end; #ifdef CONFIG_SND_PCM_TIMER if (substream->timer_running) snd_timer_interrupt(substream->timer, 1); #endif _end: snd_kill_fasync(runtime->fasync, SIGIO, POLL_IN); } EXPORT_SYMBOL(snd_pcm_period_elapsed_under_stream_lock); /** * snd_pcm_period_elapsed() - update the status of runtime for the next period by acquiring lock of * PCM substream. * @substream: the instance of PCM substream. * * This function is mostly similar to ``snd_pcm_period_elapsed_under_stream_lock()`` except for * acquiring lock of PCM substream voluntarily. * * It's typically called by any type of IRQ handler when hardware IRQ occurs to notify event that * the batch of audio data frames as the same size as the period of buffer is already processed in * audio data transmission. */ void snd_pcm_period_elapsed(struct snd_pcm_substream *substream) { if (snd_BUG_ON(!substream)) return; guard(pcm_stream_lock_irqsave)(substream); snd_pcm_period_elapsed_under_stream_lock(substream); } EXPORT_SYMBOL(snd_pcm_period_elapsed); /* * Wait until avail_min data becomes available * Returns a negative error code if any error occurs during operation. * The available space is stored on availp. When err = 0 and avail = 0 * on the capture stream, it indicates the stream is in DRAINING state. */ static int wait_for_avail(struct snd_pcm_substream *substream, snd_pcm_uframes_t *availp) { struct snd_pcm_runtime *runtime = substream->runtime; int is_playback = substream->stream == SNDRV_PCM_STREAM_PLAYBACK; wait_queue_entry_t wait; int err = 0; snd_pcm_uframes_t avail = 0; long wait_time, tout; init_waitqueue_entry(&wait, current); set_current_state(TASK_INTERRUPTIBLE); add_wait_queue(&runtime->tsleep, &wait); if (runtime->no_period_wakeup) wait_time = MAX_SCHEDULE_TIMEOUT; else { /* use wait time from substream if available */ if (substream->wait_time) { wait_time = substream->wait_time; } else { wait_time = 100; if (runtime->rate) { long t = runtime->buffer_size * 1100 / runtime->rate; wait_time = max(t, wait_time); } } wait_time = msecs_to_jiffies(wait_time); } for (;;) { if (signal_pending(current)) { err = -ERESTARTSYS; break; } /* * We need to check if space became available already * (and thus the wakeup happened already) first to close * the race of space already having become available. * This check must happen after been added to the waitqueue * and having current state be INTERRUPTIBLE. */ avail = snd_pcm_avail(substream); if (avail >= runtime->twake) break; snd_pcm_stream_unlock_irq(substream); tout = schedule_timeout(wait_time); snd_pcm_stream_lock_irq(substream); set_current_state(TASK_INTERRUPTIBLE); switch (runtime->state) { case SNDRV_PCM_STATE_SUSPENDED: err = -ESTRPIPE; goto _endloop; case SNDRV_PCM_STATE_XRUN: err = -EPIPE; goto _endloop; case SNDRV_PCM_STATE_DRAINING: if (is_playback) err = -EPIPE; else avail = 0; /* indicate draining */ goto _endloop; case SNDRV_PCM_STATE_OPEN: case SNDRV_PCM_STATE_SETUP: case SNDRV_PCM_STATE_DISCONNECTED: err = -EBADFD; goto _endloop; case SNDRV_PCM_STATE_PAUSED: continue; } if (!tout) { pcm_dbg(substream->pcm, "%s timeout (DMA or IRQ trouble?)\n", is_playback ? "playback write" : "capture read"); err = -EIO; break; } } _endloop: set_current_state(TASK_RUNNING); remove_wait_queue(&runtime->tsleep, &wait); *availp = avail; return err; } typedef int (*pcm_transfer_f)(struct snd_pcm_substream *substream, int channel, unsigned long hwoff, struct iov_iter *iter, unsigned long bytes); typedef int (*pcm_copy_f)(struct snd_pcm_substream *, snd_pcm_uframes_t, void *, snd_pcm_uframes_t, snd_pcm_uframes_t, pcm_transfer_f, bool); /* calculate the target DMA-buffer position to be written/read */ static void *get_dma_ptr(struct snd_pcm_runtime *runtime, int channel, unsigned long hwoff) { return runtime->dma_area + hwoff + channel * (runtime->dma_bytes / runtime->channels); } /* default copy ops for write; used for both interleaved and non- modes */ static int default_write_copy(struct snd_pcm_substream *substream, int channel, unsigned long hwoff, struct iov_iter *iter, unsigned long bytes) { if (copy_from_iter(get_dma_ptr(substream->runtime, channel, hwoff), bytes, iter) != bytes) return -EFAULT; return 0; } /* fill silence instead of copy data; called as a transfer helper * from __snd_pcm_lib_write() or directly from noninterleaved_copy() when * a NULL buffer is passed */ static int fill_silence(struct snd_pcm_substream *substream, int channel, unsigned long hwoff, struct iov_iter *iter, unsigned long bytes) { struct snd_pcm_runtime *runtime = substream->runtime; if (substream->stream != SNDRV_PCM_STREAM_PLAYBACK) return 0; if (substream->ops->fill_silence) return substream->ops->fill_silence(substream, channel, hwoff, bytes); snd_pcm_format_set_silence(runtime->format, get_dma_ptr(runtime, channel, hwoff), bytes_to_samples(runtime, bytes)); return 0; } /* default copy ops for read; used for both interleaved and non- modes */ static int default_read_copy(struct snd_pcm_substream *substream, int channel, unsigned long hwoff, struct iov_iter *iter, unsigned long bytes) { if (copy_to_iter(get_dma_ptr(substream->runtime, channel, hwoff), bytes, iter) != bytes) return -EFAULT; return 0; } /* call transfer with the filled iov_iter */ static int do_transfer(struct snd_pcm_substream *substream, int c, unsigned long hwoff, void *data, unsigned long bytes, pcm_transfer_f transfer, bool in_kernel) { struct iov_iter iter; int err, type; if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) type = ITER_SOURCE; else type = ITER_DEST; if (in_kernel) { struct kvec kvec = { data, bytes }; iov_iter_kvec(&iter, type, &kvec, 1, bytes); return transfer(substream, c, hwoff, &iter, bytes); } err = import_ubuf(type, (__force void __user *)data, bytes, &iter); if (err) return err; return transfer(substream, c, hwoff, &iter, bytes); } /* call transfer function with the converted pointers and sizes; * for interleaved mode, it's one shot for all samples */ static int interleaved_copy(struct snd_pcm_substream *substream, snd_pcm_uframes_t hwoff, void *data, snd_pcm_uframes_t off, snd_pcm_uframes_t frames, pcm_transfer_f transfer, bool in_kernel) { struct snd_pcm_runtime *runtime = substream->runtime; /* convert to bytes */ hwoff = frames_to_bytes(runtime, hwoff); off = frames_to_bytes(runtime, off); frames = frames_to_bytes(runtime, frames); return do_transfer(substream, 0, hwoff, data + off, frames, transfer, in_kernel); } /* call transfer function with the converted pointers and sizes for each * non-interleaved channel; when buffer is NULL, silencing instead of copying */ static int noninterleaved_copy(struct snd_pcm_substream *substream, snd_pcm_uframes_t hwoff, void *data, snd_pcm_uframes_t off, snd_pcm_uframes_t frames, pcm_transfer_f transfer, bool in_kernel) { struct snd_pcm_runtime *runtime = substream->runtime; int channels = runtime->channels; void **bufs = data; int c, err; /* convert to bytes; note that it's not frames_to_bytes() here. * in non-interleaved mode, we copy for each channel, thus * each copy is n_samples bytes x channels = whole frames. */ off = samples_to_bytes(runtime, off); frames = samples_to_bytes(runtime, frames); hwoff = samples_to_bytes(runtime, hwoff); for (c = 0; c < channels; ++c, ++bufs) { if (!data || !*bufs) err = fill_silence(substream, c, hwoff, NULL, frames); else err = do_transfer(substream, c, hwoff, *bufs + off, frames, transfer, in_kernel); if (err < 0) return err; } return 0; } /* fill silence on the given buffer position; * called from snd_pcm_playback_silence() */ static int fill_silence_frames(struct snd_pcm_substream *substream, snd_pcm_uframes_t off, snd_pcm_uframes_t frames) { if (substream->runtime->access == SNDRV_PCM_ACCESS_RW_INTERLEAVED || substream->runtime->access == SNDRV_PCM_ACCESS_MMAP_INTERLEAVED) return interleaved_copy(substream, off, NULL, 0, frames, fill_silence, true); else return noninterleaved_copy(substream, off, NULL, 0, frames, fill_silence, true); } /* sanity-check for read/write methods */ static int pcm_sanity_check(struct snd_pcm_substream *substream) { struct snd_pcm_runtime *runtime; if (PCM_RUNTIME_CHECK(substream)) return -ENXIO; runtime = substream->runtime; if (snd_BUG_ON(!substream->ops->copy && !runtime->dma_area)) return -EINVAL; if (runtime->state == SNDRV_PCM_STATE_OPEN) return -EBADFD; return 0; } static int pcm_accessible_state(struct snd_pcm_runtime *runtime) { switch (runtime->state) { case SNDRV_PCM_STATE_PREPARED: case SNDRV_PCM_STATE_RUNNING: case SNDRV_PCM_STATE_PAUSED: return 0; case SNDRV_PCM_STATE_XRUN: return -EPIPE; case SNDRV_PCM_STATE_SUSPENDED: return -ESTRPIPE; default: return -EBADFD; } } /* update to the given appl_ptr and call ack callback if needed; * when an error is returned, take back to the original value */ int pcm_lib_apply_appl_ptr(struct snd_pcm_substream *substream, snd_pcm_uframes_t appl_ptr) { struct snd_pcm_runtime *runtime = substream->runtime; snd_pcm_uframes_t old_appl_ptr = runtime->control->appl_ptr; snd_pcm_sframes_t diff; int ret; if (old_appl_ptr == appl_ptr) return 0; if (appl_ptr >= runtime->boundary) return -EINVAL; /* * check if a rewind is requested by the application */ if (substream->runtime->info & SNDRV_PCM_INFO_NO_REWINDS) { diff = appl_ptr - old_appl_ptr; if (diff >= 0) { if (diff > runtime->buffer_size) return -EINVAL; } else { if (runtime->boundary + diff > runtime->buffer_size) return -EINVAL; } } runtime->control->appl_ptr = appl_ptr; if (substream->ops->ack) { ret = substream->ops->ack(substream); if (ret < 0) { runtime->control->appl_ptr = old_appl_ptr; if (ret == -EPIPE) __snd_pcm_xrun(substream); return ret; } } trace_applptr(substream, old_appl_ptr, appl_ptr); return 0; } /* the common loop for read/write data */ snd_pcm_sframes_t __snd_pcm_lib_xfer(struct snd_pcm_substream *substream, void *data, bool interleaved, snd_pcm_uframes_t size, bool in_kernel) { struct snd_pcm_runtime *runtime = substream->runtime; snd_pcm_uframes_t xfer = 0; snd_pcm_uframes_t offset = 0; snd_pcm_uframes_t avail; pcm_copy_f writer; pcm_transfer_f transfer; bool nonblock; bool is_playback; int err; err = pcm_sanity_check(substream); if (err < 0) return err; is_playback = substream->stream == SNDRV_PCM_STREAM_PLAYBACK; if (interleaved) { if (runtime->access != SNDRV_PCM_ACCESS_RW_INTERLEAVED && runtime->channels > 1) return -EINVAL; writer = interleaved_copy; } else { if (runtime->access != SNDRV_PCM_ACCESS_RW_NONINTERLEAVED) return -EINVAL; writer = noninterleaved_copy; } if (!data) { if (is_playback) transfer = fill_silence; else return -EINVAL; } else { if (substream->ops->copy) transfer = substream->ops->copy; else transfer = is_playback ? default_write_copy : default_read_copy; } if (size == 0) return 0; nonblock = !!(substream->f_flags & O_NONBLOCK); snd_pcm_stream_lock_irq(substream); err = pcm_accessible_state(runtime); if (err < 0) goto _end_unlock; runtime->twake = runtime->control->avail_min ? : 1; if (runtime->state == SNDRV_PCM_STATE_RUNNING) snd_pcm_update_hw_ptr(substream); /* * If size < start_threshold, wait indefinitely. Another * thread may start capture */ if (!is_playback && runtime->state == SNDRV_PCM_STATE_PREPARED && size >= runtime->start_threshold) { err = snd_pcm_start(substream); if (err < 0) goto _end_unlock; } avail = snd_pcm_avail(substream); while (size > 0) { snd_pcm_uframes_t frames, appl_ptr, appl_ofs; snd_pcm_uframes_t cont; if (!avail) { if (!is_playback && runtime->state == SNDRV_PCM_STATE_DRAINING) { snd_pcm_stop(substream, SNDRV_PCM_STATE_SETUP); goto _end_unlock; } if (nonblock) { err = -EAGAIN; goto _end_unlock; } runtime->twake = min_t(snd_pcm_uframes_t, size, runtime->control->avail_min ? : 1); err = wait_for_avail(substream, &avail); if (err < 0) goto _end_unlock; if (!avail) continue; /* draining */ } frames = size > avail ? avail : size; appl_ptr = READ_ONCE(runtime->control->appl_ptr); appl_ofs = appl_ptr % runtime->buffer_size; cont = runtime->buffer_size - appl_ofs; if (frames > cont) frames = cont; if (snd_BUG_ON(!frames)) { err = -EINVAL; goto _end_unlock; } if (!atomic_inc_unless_negative(&runtime->buffer_accessing)) { err = -EBUSY; goto _end_unlock; } snd_pcm_stream_unlock_irq(substream); if (!is_playback) snd_pcm_dma_buffer_sync(substream, SNDRV_DMA_SYNC_CPU); err = writer(substream, appl_ofs, data, offset, frames, transfer, in_kernel); if (is_playback) snd_pcm_dma_buffer_sync(substream, SNDRV_DMA_SYNC_DEVICE); snd_pcm_stream_lock_irq(substream); atomic_dec(&runtime->buffer_accessing); if (err < 0) goto _end_unlock; err = pcm_accessible_state(runtime); if (err < 0) goto _end_unlock; appl_ptr += frames; if (appl_ptr >= runtime->boundary) appl_ptr -= runtime->boundary; err = pcm_lib_apply_appl_ptr(substream, appl_ptr); if (err < 0) goto _end_unlock; offset += frames; size -= frames; xfer += frames; avail -= frames; if (is_playback && runtime->state == SNDRV_PCM_STATE_PREPARED && snd_pcm_playback_hw_avail(runtime) >= (snd_pcm_sframes_t)runtime->start_threshold) { err = snd_pcm_start(substream); if (err < 0) goto _end_unlock; } } _end_unlock: runtime->twake = 0; if (xfer > 0 && err >= 0) snd_pcm_update_state(substream, runtime); snd_pcm_stream_unlock_irq(substream); return xfer > 0 ? (snd_pcm_sframes_t)xfer : err; } EXPORT_SYMBOL(__snd_pcm_lib_xfer); /* * standard channel mapping helpers */ /* default channel maps for multi-channel playbacks, up to 8 channels */ const struct snd_pcm_chmap_elem snd_pcm_std_chmaps[] = { { .channels = 1, .map = { SNDRV_CHMAP_MONO } }, { .channels = 2, .map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR } }, { .channels = 4, .map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR, SNDRV_CHMAP_RL, SNDRV_CHMAP_RR } }, { .channels = 6, .map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR, SNDRV_CHMAP_RL, SNDRV_CHMAP_RR, SNDRV_CHMAP_FC, SNDRV_CHMAP_LFE } }, { .channels = 8, .map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR, SNDRV_CHMAP_RL, SNDRV_CHMAP_RR, SNDRV_CHMAP_FC, SNDRV_CHMAP_LFE, SNDRV_CHMAP_SL, SNDRV_CHMAP_SR } }, { } }; EXPORT_SYMBOL_GPL(snd_pcm_std_chmaps); /* alternative channel maps with CLFE <-> surround swapped for 6/8 channels */ const struct snd_pcm_chmap_elem snd_pcm_alt_chmaps[] = { { .channels = 1, .map = { SNDRV_CHMAP_MONO } }, { .channels = 2, .map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR } }, { .channels = 4, .map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR, SNDRV_CHMAP_RL, SNDRV_CHMAP_RR } }, { .channels = 6, .map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR, SNDRV_CHMAP_FC, SNDRV_CHMAP_LFE, SNDRV_CHMAP_RL, SNDRV_CHMAP_RR } }, { .channels = 8, .map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR, SNDRV_CHMAP_FC, SNDRV_CHMAP_LFE, SNDRV_CHMAP_RL, SNDRV_CHMAP_RR, SNDRV_CHMAP_SL, SNDRV_CHMAP_SR } }, { } }; EXPORT_SYMBOL_GPL(snd_pcm_alt_chmaps); static bool valid_chmap_channels(const struct snd_pcm_chmap *info, int ch) { if (ch > info->max_channels) return false; return !info->channel_mask || (info->channel_mask & (1U << ch)); } static int pcm_chmap_ctl_info(struct snd_kcontrol *kcontrol, struct snd_ctl_elem_info *uinfo) { struct snd_pcm_chmap *info = snd_kcontrol_chip(kcontrol); uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER; uinfo->count = info->max_channels; uinfo->value.integer.min = 0; uinfo->value.integer.max = SNDRV_CHMAP_LAST; return 0; } /* get callback for channel map ctl element * stores the channel position firstly matching with the current channels */ static int pcm_chmap_ctl_get(struct snd_kcontrol *kcontrol, struct snd_ctl_elem_value *ucontrol) { struct snd_pcm_chmap *info = snd_kcontrol_chip(kcontrol); unsigned int idx = snd_ctl_get_ioffidx(kcontrol, &ucontrol->id); struct snd_pcm_substream *substream; const struct snd_pcm_chmap_elem *map; if (!info->chmap) return -EINVAL; substream = snd_pcm_chmap_substream(info, idx); if (!substream) return -ENODEV; memset(ucontrol->value.integer.value, 0, sizeof(long) * info->max_channels); if (!substream->runtime) return 0; /* no channels set */ for (map = info->chmap; map->channels; map++) { int i; if (map->channels == substream->runtime->channels && valid_chmap_channels(info, map->channels)) { for (i = 0; i < map->channels; i++) ucontrol->value.integer.value[i] = map->map[i]; return 0; } } return -EINVAL; } /* tlv callback for channel map ctl element * expands the pre-defined channel maps in a form of TLV */ static int pcm_chmap_ctl_tlv(struct snd_kcontrol *kcontrol, int op_flag, unsigned int size, unsigned int __user *tlv) { struct snd_pcm_chmap *info = snd_kcontrol_chip(kcontrol); const struct snd_pcm_chmap_elem *map; unsigned int __user *dst; int c, count = 0; if (!info->chmap) return -EINVAL; if (size < 8) return -ENOMEM; if (put_user(SNDRV_CTL_TLVT_CONTAINER, tlv)) return -EFAULT; size -= 8; dst = tlv + 2; for (map = info->chmap; map->channels; map++) { int chs_bytes = map->channels * 4; if (!valid_chmap_channels(info, map->channels)) continue; if (size < 8) return -ENOMEM; if (put_user(SNDRV_CTL_TLVT_CHMAP_FIXED, dst) || put_user(chs_bytes, dst + 1)) return -EFAULT; dst += 2; size -= 8; count += 8; if (size < chs_bytes) return -ENOMEM; size -= chs_bytes; count += chs_bytes; for (c = 0; c < map->channels; c++) { if (put_user(map->map[c], dst)) return -EFAULT; dst++; } } if (put_user(count, tlv + 1)) return -EFAULT; return 0; } static void pcm_chmap_ctl_private_free(struct snd_kcontrol *kcontrol) { struct snd_pcm_chmap *info = snd_kcontrol_chip(kcontrol); info->pcm->streams[info->stream].chmap_kctl = NULL; kfree(info); } /** * snd_pcm_add_chmap_ctls - create channel-mapping control elements * @pcm: the assigned PCM instance * @stream: stream direction * @chmap: channel map elements (for query) * @max_channels: the max number of channels for the stream * @private_value: the value passed to each kcontrol's private_value field * @info_ret: store struct snd_pcm_chmap instance if non-NULL * * Create channel-mapping control elements assigned to the given PCM stream(s). * Return: Zero if successful, or a negative error value. */ int snd_pcm_add_chmap_ctls(struct snd_pcm *pcm, int stream, const struct snd_pcm_chmap_elem *chmap, int max_channels, unsigned long private_value, struct snd_pcm_chmap **info_ret) { struct snd_pcm_chmap *info; struct snd_kcontrol_new knew = { .iface = SNDRV_CTL_ELEM_IFACE_PCM, .access = SNDRV_CTL_ELEM_ACCESS_READ | SNDRV_CTL_ELEM_ACCESS_VOLATILE | SNDRV_CTL_ELEM_ACCESS_TLV_READ | SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK, .info = pcm_chmap_ctl_info, .get = pcm_chmap_ctl_get, .tlv.c = pcm_chmap_ctl_tlv, }; int err; if (WARN_ON(pcm->streams[stream].chmap_kctl)) return -EBUSY; info = kzalloc(sizeof(*info), GFP_KERNEL); if (!info) return -ENOMEM; info->pcm = pcm; info->stream = stream; info->chmap = chmap; info->max_channels = max_channels; if (stream == SNDRV_PCM_STREAM_PLAYBACK) knew.name = "Playback Channel Map"; else knew.name = "Capture Channel Map"; knew.device = pcm->device; knew.count = pcm->streams[stream].substream_count; knew.private_value = private_value; info->kctl = snd_ctl_new1(&knew, info); if (!info->kctl) { kfree(info); return -ENOMEM; } info->kctl->private_free = pcm_chmap_ctl_private_free; err = snd_ctl_add(pcm->card, info->kctl); if (err < 0) return err; pcm->streams[stream].chmap_kctl = info->kctl; if (info_ret) *info_ret = info; return 0; } EXPORT_SYMBOL_GPL(snd_pcm_add_chmap_ctls);