/* * Loopback soundcard * * Original code: * Copyright (c) by Jaroslav Kysela * * More accurate positioning and full-duplex support: * Copyright (c) Ahmet İnan * * Major (almost complete) rewrite: * Copyright (c) by Takashi Iwai * * A next major update in 2010 (separate timers for playback and capture): * Copyright (c) Jaroslav Kysela * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA * */ #include #include #include #include #include #include #include #include #include #include #include #include MODULE_AUTHOR("Jaroslav Kysela "); MODULE_DESCRIPTION("A loopback soundcard"); MODULE_LICENSE("GPL"); MODULE_SUPPORTED_DEVICE("{{ALSA,Loopback soundcard}}"); #define MAX_PCM_SUBSTREAMS 8 static int index[SNDRV_CARDS] = SNDRV_DEFAULT_IDX; /* Index 0-MAX */ static char *id[SNDRV_CARDS] = SNDRV_DEFAULT_STR; /* ID for this card */ static int enable[SNDRV_CARDS] = {1, [1 ... (SNDRV_CARDS - 1)] = 0}; static int pcm_substreams[SNDRV_CARDS] = {[0 ... (SNDRV_CARDS - 1)] = 8}; static int pcm_notify[SNDRV_CARDS]; module_param_array(index, int, NULL, 0444); MODULE_PARM_DESC(index, "Index value for loopback soundcard."); module_param_array(id, charp, NULL, 0444); MODULE_PARM_DESC(id, "ID string for loopback soundcard."); module_param_array(enable, bool, NULL, 0444); MODULE_PARM_DESC(enable, "Enable this loopback soundcard."); module_param_array(pcm_substreams, int, NULL, 0444); MODULE_PARM_DESC(pcm_substreams, "PCM substreams # (1-8) for loopback driver."); module_param_array(pcm_notify, int, NULL, 0444); MODULE_PARM_DESC(pcm_notify, "Break capture when PCM format/rate/channels changes."); #define NO_PITCH 100000 struct loopback_pcm; struct loopback_cable { spinlock_t lock; struct loopback_pcm *streams[2]; struct snd_pcm_hardware hw; /* flags */ unsigned int valid; unsigned int running; }; struct loopback_setup { unsigned int notify: 1; unsigned int rate_shift; unsigned int format; unsigned int rate; unsigned int channels; struct snd_ctl_elem_id active_id; struct snd_ctl_elem_id format_id; struct snd_ctl_elem_id rate_id; struct snd_ctl_elem_id channels_id; }; struct loopback { struct snd_card *card; struct mutex cable_lock; struct loopback_cable *cables[MAX_PCM_SUBSTREAMS][2]; struct snd_pcm *pcm[2]; struct loopback_setup setup[MAX_PCM_SUBSTREAMS][2]; }; struct loopback_pcm { struct loopback *loopback; struct snd_pcm_substream *substream; struct loopback_cable *cable; unsigned int pcm_buffer_size; unsigned int buf_pos; /* position in buffer */ unsigned int silent_size; /* PCM parameters */ unsigned int pcm_period_size; unsigned int pcm_bps; /* bytes per second */ unsigned int pcm_salign; /* bytes per sample * channels */ unsigned int pcm_rate_shift; /* rate shift value */ /* flags */ unsigned int period_update_pending :1; /* timer stuff */ unsigned int irq_pos; /* fractional IRQ position */ unsigned int period_size_frac; unsigned long last_jiffies; struct timer_list timer; }; static struct platform_device *devices[SNDRV_CARDS]; static inline unsigned int byte_pos(struct loopback_pcm *dpcm, unsigned int x) { if (dpcm->pcm_rate_shift == NO_PITCH) { x /= HZ; } else { x = div_u64(NO_PITCH * (unsigned long long)x, HZ * (unsigned long long)dpcm->pcm_rate_shift); } return x - (x % dpcm->pcm_salign); } static inline unsigned int frac_pos(struct loopback_pcm *dpcm, unsigned int x) { if (dpcm->pcm_rate_shift == NO_PITCH) { /* no pitch */ return x * HZ; } else { x = div_u64(dpcm->pcm_rate_shift * (unsigned long long)x * HZ, NO_PITCH); } return x; } static inline struct loopback_setup *get_setup(struct loopback_pcm *dpcm) { int device = dpcm->substream->pstr->pcm->device; if (dpcm->substream->stream == SNDRV_PCM_STREAM_PLAYBACK) device ^= 1; return &dpcm->loopback->setup[dpcm->substream->number][device]; } static inline unsigned int get_notify(struct loopback_pcm *dpcm) { return get_setup(dpcm)->notify; } static inline unsigned int get_rate_shift(struct loopback_pcm *dpcm) { return get_setup(dpcm)->rate_shift; } static void loopback_timer_start(struct loopback_pcm *dpcm) { unsigned long tick; unsigned int rate_shift = get_rate_shift(dpcm); if (rate_shift != dpcm->pcm_rate_shift) { dpcm->pcm_rate_shift = rate_shift; dpcm->period_size_frac = frac_pos(dpcm, dpcm->pcm_period_size); } if (dpcm->period_size_frac <= dpcm->irq_pos) { dpcm->irq_pos %= dpcm->period_size_frac; dpcm->period_update_pending = 1; } tick = dpcm->period_size_frac - dpcm->irq_pos; tick = (tick + dpcm->pcm_bps - 1) / dpcm->pcm_bps; dpcm->timer.expires = jiffies + tick; add_timer(&dpcm->timer); } static inline void loopback_timer_stop(struct loopback_pcm *dpcm) { del_timer(&dpcm->timer); dpcm->timer.expires = 0; } #define CABLE_VALID_PLAYBACK (1 << SNDRV_PCM_STREAM_PLAYBACK) #define CABLE_VALID_CAPTURE (1 << SNDRV_PCM_STREAM_CAPTURE) #define CABLE_VALID_BOTH (CABLE_VALID_PLAYBACK|CABLE_VALID_CAPTURE) static int loopback_check_format(struct loopback_cable *cable, int stream) { struct snd_pcm_runtime *runtime, *cruntime; struct loopback_setup *setup; struct snd_card *card; int check; if (cable->valid != CABLE_VALID_BOTH) { if (stream == SNDRV_PCM_STREAM_PLAYBACK) goto __notify; return 0; } runtime = cable->streams[SNDRV_PCM_STREAM_PLAYBACK]-> substream->runtime; cruntime = cable->streams[SNDRV_PCM_STREAM_CAPTURE]-> substream->runtime; check = runtime->format != cruntime->format || runtime->rate != cruntime->rate || runtime->channels != cruntime->channels; if (!check) return 0; if (stream == SNDRV_PCM_STREAM_CAPTURE) { return -EIO; } else { snd_pcm_stop(cable->streams[SNDRV_PCM_STREAM_CAPTURE]-> substream, SNDRV_PCM_STATE_DRAINING); __notify: runtime = cable->streams[SNDRV_PCM_STREAM_PLAYBACK]-> substream->runtime; setup = get_setup(cable->streams[SNDRV_PCM_STREAM_PLAYBACK]); card = cable->streams[SNDRV_PCM_STREAM_PLAYBACK]->loopback->card; if (setup->format != runtime->format) { snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_VALUE, &setup->format_id); setup->format = runtime->format; } if (setup->rate != runtime->rate) { snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_VALUE, &setup->rate_id); setup->rate = runtime->rate; } if (setup->channels != runtime->channels) { snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_VALUE, &setup->channels_id); setup->channels = runtime->channels; } } return 0; } static void loopback_active_notify(struct loopback_pcm *dpcm) { snd_ctl_notify(dpcm->loopback->card, SNDRV_CTL_EVENT_MASK_VALUE, &get_setup(dpcm)->active_id); } static int loopback_trigger(struct snd_pcm_substream *substream, int cmd) { struct snd_pcm_runtime *runtime = substream->runtime; struct loopback_pcm *dpcm = runtime->private_data; struct loopback_cable *cable = dpcm->cable; int err; switch (cmd) { case SNDRV_PCM_TRIGGER_START: err = loopback_check_format(cable, substream->stream); if (err < 0) return err; dpcm->last_jiffies = jiffies; dpcm->pcm_rate_shift = 0; loopback_timer_start(dpcm); cable->running |= (1 << substream->stream); if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) loopback_active_notify(dpcm); break; case SNDRV_PCM_TRIGGER_STOP: cable->running &= ~(1 << substream->stream); loopback_timer_stop(dpcm); if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) loopback_active_notify(dpcm); break; default: return -EINVAL; } return 0; } static void params_change_substream(struct loopback_pcm *dpcm, struct snd_pcm_runtime *runtime) { struct snd_pcm_runtime *dst_runtime; if (dpcm == NULL || dpcm->substream == NULL) return; dst_runtime = dpcm->substream->runtime; if (dst_runtime == NULL) return; dst_runtime->hw = dpcm->cable->hw; } static void params_change(struct snd_pcm_substream *substream) { struct snd_pcm_runtime *runtime = substream->runtime; struct loopback_pcm *dpcm = runtime->private_data; struct loopback_cable *cable = dpcm->cable; cable->hw.formats = (1ULL << runtime->format); cable->hw.rate_min = runtime->rate; cable->hw.rate_max = runtime->rate; cable->hw.channels_min = runtime->channels; cable->hw.channels_max = runtime->channels; params_change_substream(cable->streams[SNDRV_PCM_STREAM_PLAYBACK], runtime); params_change_substream(cable->streams[SNDRV_PCM_STREAM_CAPTURE], runtime); } static int loopback_prepare(struct snd_pcm_substream *substream) { struct snd_pcm_runtime *runtime = substream->runtime; struct loopback_pcm *dpcm = runtime->private_data; struct loopback_cable *cable = dpcm->cable; int bps, salign; salign = (snd_pcm_format_width(runtime->format) * runtime->channels) / 8; bps = salign * runtime->rate; if (bps <= 0 || salign <= 0) return -EINVAL; dpcm->buf_pos = 0; dpcm->pcm_buffer_size = frames_to_bytes(runtime, runtime->buffer_size); if (substream->stream == SNDRV_PCM_STREAM_CAPTURE) { /* clear capture buffer */ dpcm->silent_size = dpcm->pcm_buffer_size; snd_pcm_format_set_silence(runtime->format, runtime->dma_area, runtime->buffer_size * runtime->channels); } dpcm->irq_pos = 0; dpcm->period_update_pending = 0; dpcm->pcm_bps = bps; dpcm->pcm_salign = salign; dpcm->pcm_period_size = frames_to_bytes(runtime, runtime->period_size); mutex_lock(&dpcm->loopback->cable_lock); if (!(cable->valid & ~(1 << substream->stream)) || (get_setup(dpcm)->notify && substream->stream == SNDRV_PCM_STREAM_PLAYBACK)) params_change(substream); cable->valid |= 1 << substream->stream; mutex_unlock(&dpcm->loopback->cable_lock); return 0; } static void clear_capture_buf(struct loopback_pcm *dpcm, unsigned int bytes) { struct snd_pcm_runtime *runtime = dpcm->substream->runtime; char *dst = runtime->dma_area; unsigned int dst_off = dpcm->buf_pos; if (dpcm->silent_size >= dpcm->pcm_buffer_size) return; if (dpcm->silent_size + bytes > dpcm->pcm_buffer_size) bytes = dpcm->pcm_buffer_size - dpcm->silent_size; for (;;) { unsigned int size = bytes; if (dst_off + size > dpcm->pcm_buffer_size) size = dpcm->pcm_buffer_size - dst_off; snd_pcm_format_set_silence(runtime->format, dst + dst_off, bytes_to_frames(runtime, size) * runtime->channels); dpcm->silent_size += size; bytes -= size; if (!bytes) break; dst_off = 0; } } static void copy_play_buf(struct loopback_pcm *play, struct loopback_pcm *capt, unsigned int bytes) { struct snd_pcm_runtime *runtime = play->substream->runtime; char *src = runtime->dma_area; char *dst = capt->substream->runtime->dma_area; unsigned int src_off = play->buf_pos; unsigned int dst_off = capt->buf_pos; unsigned int clear_bytes = 0; /* check if playback is draining, trim the capture copy size * when our pointer is at the end of playback ring buffer */ if (runtime->status->state == SNDRV_PCM_STATE_DRAINING && snd_pcm_playback_hw_avail(runtime) < runtime->buffer_size) { snd_pcm_uframes_t appl_ptr, appl_ptr1, diff; appl_ptr = appl_ptr1 = runtime->control->appl_ptr; appl_ptr1 -= appl_ptr1 % runtime->buffer_size; appl_ptr1 += play->buf_pos / play->pcm_salign; if (appl_ptr < appl_ptr1) appl_ptr1 -= runtime->buffer_size; diff = (appl_ptr - appl_ptr1) * play->pcm_salign; if (diff < bytes) { clear_bytes = bytes - diff; bytes = diff; } } for (;;) { unsigned int size = bytes; if (src_off + size > play->pcm_buffer_size) size = play->pcm_buffer_size - src_off; if (dst_off + size > capt->pcm_buffer_size) size = capt->pcm_buffer_size - dst_off; memcpy(dst + dst_off, src + src_off, size); capt->silent_size = 0; bytes -= size; if (!bytes) break; src_off = (src_off + size) % play->pcm_buffer_size; dst_off = (dst_off + size) % capt->pcm_buffer_size; } if (clear_bytes > 0) { clear_capture_buf(capt, clear_bytes); capt->silent_size = 0; } } #define BYTEPOS_UPDATE_POSONLY 0 #define BYTEPOS_UPDATE_CLEAR 1 #define BYTEPOS_UPDATE_COPY 2 static void loopback_bytepos_update(struct loopback_pcm *dpcm, unsigned int delta, unsigned int cmd) { unsigned int count; unsigned long last_pos; last_pos = byte_pos(dpcm, dpcm->irq_pos); dpcm->irq_pos += delta * dpcm->pcm_bps; count = byte_pos(dpcm, dpcm->irq_pos) - last_pos; if (!count) return; if (cmd == BYTEPOS_UPDATE_CLEAR) clear_capture_buf(dpcm, count); else if (cmd == BYTEPOS_UPDATE_COPY) copy_play_buf(dpcm->cable->streams[SNDRV_PCM_STREAM_PLAYBACK], dpcm->cable->streams[SNDRV_PCM_STREAM_CAPTURE], count); dpcm->buf_pos += count; dpcm->buf_pos %= dpcm->pcm_buffer_size; if (dpcm->irq_pos >= dpcm->period_size_frac) { dpcm->irq_pos %= dpcm->period_size_frac; dpcm->period_update_pending = 1; } } static void loopback_pos_update(struct loopback_cable *cable) { struct loopback_pcm *dpcm_play = cable->streams[SNDRV_PCM_STREAM_PLAYBACK]; struct loopback_pcm *dpcm_capt = cable->streams[SNDRV_PCM_STREAM_CAPTURE]; unsigned long delta_play = 0, delta_capt = 0; spin_lock(&cable->lock); if (cable->running & (1 << SNDRV_PCM_STREAM_PLAYBACK)) { delta_play = jiffies - dpcm_play->last_jiffies; dpcm_play->last_jiffies += delta_play; } if (cable->running & (1 << SNDRV_PCM_STREAM_CAPTURE)) { delta_capt = jiffies - dpcm_capt->last_jiffies; dpcm_capt->last_jiffies += delta_capt; } if (delta_play == 0 && delta_capt == 0) { spin_unlock(&cable->lock); return; } if (delta_play > delta_capt) { loopback_bytepos_update(dpcm_play, delta_play - delta_capt, BYTEPOS_UPDATE_POSONLY); delta_play = delta_capt; } else if (delta_play < delta_capt) { loopback_bytepos_update(dpcm_capt, delta_capt - delta_play, BYTEPOS_UPDATE_CLEAR); delta_capt = delta_play; } if (delta_play == 0 && delta_capt == 0) { spin_unlock(&cable->lock); return; } /* note delta_capt == delta_play at this moment */ loopback_bytepos_update(dpcm_capt, delta_capt, BYTEPOS_UPDATE_COPY); loopback_bytepos_update(dpcm_play, delta_play, BYTEPOS_UPDATE_POSONLY); spin_unlock(&cable->lock); } static void loopback_timer_function(unsigned long data) { struct loopback_pcm *dpcm = (struct loopback_pcm *)data; int stream; loopback_pos_update(dpcm->cable); stream = dpcm->substream->stream; if (dpcm->cable->running & (1 << stream)) loopback_timer_start(dpcm); if (dpcm->period_update_pending) { dpcm->period_update_pending = 0; if (dpcm->cable->running & (1 << stream)) snd_pcm_period_elapsed(dpcm->substream); } } static snd_pcm_uframes_t loopback_pointer(struct snd_pcm_substream *substream) { struct snd_pcm_runtime *runtime = substream->runtime; struct loopback_pcm *dpcm = runtime->private_data; loopback_pos_update(dpcm->cable); return bytes_to_frames(runtime, dpcm->buf_pos); } static struct snd_pcm_hardware loopback_pcm_hardware = { .info = (SNDRV_PCM_INFO_INTERLEAVED | SNDRV_PCM_INFO_MMAP | SNDRV_PCM_INFO_MMAP_VALID), .formats = (SNDRV_PCM_FMTBIT_S16_LE | SNDRV_PCM_FMTBIT_S16_BE | SNDRV_PCM_FMTBIT_S32_LE | SNDRV_PCM_FMTBIT_S32_BE | SNDRV_PCM_FMTBIT_FLOAT_LE | SNDRV_PCM_FMTBIT_FLOAT_BE), .rates = SNDRV_PCM_RATE_CONTINUOUS | SNDRV_PCM_RATE_8000_192000, .rate_min = 8000, .rate_max = 192000, .channels_min = 1, .channels_max = 32, .buffer_bytes_max = 2 * 1024 * 1024, .period_bytes_min = 64, /* note check overflow in frac_pos() using pcm_rate_shift before changing period_bytes_max value */ .period_bytes_max = 1024 * 1024, .periods_min = 1, .periods_max = 1024, .fifo_size = 0, }; static void loopback_runtime_free(struct snd_pcm_runtime *runtime) { struct loopback_pcm *dpcm = runtime->private_data; kfree(dpcm); } static int loopback_hw_params(struct snd_pcm_substream *substream, struct snd_pcm_hw_params *params) { return snd_pcm_lib_malloc_pages(substream, params_buffer_bytes(params)); } static int loopback_hw_free(struct snd_pcm_substream *substream) { struct snd_pcm_runtime *runtime = substream->runtime; struct loopback_pcm *dpcm = runtime->private_data; struct loopback_cable *cable = dpcm->cable; mutex_lock(&dpcm->loopback->cable_lock); cable->valid &= ~(1 << substream->stream); mutex_unlock(&dpcm->loopback->cable_lock); return snd_pcm_lib_free_pages(substream); } static unsigned int get_cable_index(struct snd_pcm_substream *substream) { if (!substream->pcm->device) return substream->stream; else return !substream->stream; } static int rule_format(struct snd_pcm_hw_params *params, struct snd_pcm_hw_rule *rule) { struct snd_pcm_hardware *hw = rule->private; struct snd_mask *maskp = hw_param_mask(params, rule->var); maskp->bits[0] &= (u_int32_t)hw->formats; maskp->bits[1] &= (u_int32_t)(hw->formats >> 32); memset(maskp->bits + 2, 0, (SNDRV_MASK_MAX-64) / 8); /* clear rest */ if (! maskp->bits[0] && ! maskp->bits[1]) return -EINVAL; return 0; } static int rule_rate(struct snd_pcm_hw_params *params, struct snd_pcm_hw_rule *rule) { struct snd_pcm_hardware *hw = rule->private; struct snd_interval t; t.min = hw->rate_min; t.max = hw->rate_max; t.openmin = t.openmax = 0; t.integer = 0; return snd_interval_refine(hw_param_interval(params, rule->var), &t); } static int rule_channels(struct snd_pcm_hw_params *params, struct snd_pcm_hw_rule *rule) { struct snd_pcm_hardware *hw = rule->private; struct snd_interval t; t.min = hw->channels_min; t.max = hw->channels_max; t.openmin = t.openmax = 0; t.integer = 0; return snd_interval_refine(hw_param_interval(params, rule->var), &t); } static int loopback_open(struct snd_pcm_substream *substream) { struct snd_pcm_runtime *runtime = substream->runtime; struct loopback *loopback = substream->private_data; struct loopback_pcm *dpcm; struct loopback_cable *cable; int err = 0; int dev = get_cable_index(substream); mutex_lock(&loopback->cable_lock); dpcm = kzalloc(sizeof(*dpcm), GFP_KERNEL); if (!dpcm) { err = -ENOMEM; goto unlock; } dpcm->loopback = loopback; dpcm->substream = substream; setup_timer(&dpcm->timer, loopback_timer_function, (unsigned long)dpcm); cable = loopback->cables[substream->number][dev]; if (!cable) { cable = kzalloc(sizeof(*cable), GFP_KERNEL); if (!cable) { kfree(dpcm); err = -ENOMEM; goto unlock; } spin_lock_init(&cable->lock); cable->hw = loopback_pcm_hardware; loopback->cables[substream->number][dev] = cable; } dpcm->cable = cable; cable->streams[substream->stream] = dpcm; snd_pcm_hw_constraint_integer(runtime, SNDRV_PCM_HW_PARAM_PERIODS); /* use dynamic rules based on actual runtime->hw values */ /* note that the default rules created in the PCM midlevel code */ /* are cached -> they do not reflect the actual state */ err = snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_FORMAT, rule_format, &runtime->hw, SNDRV_PCM_HW_PARAM_FORMAT, -1); if (err < 0) goto unlock; err = snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_RATE, rule_rate, &runtime->hw, SNDRV_PCM_HW_PARAM_RATE, -1); if (err < 0) goto unlock; err = snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_CHANNELS, rule_channels, &runtime->hw, SNDRV_PCM_HW_PARAM_CHANNELS, -1); if (err < 0) goto unlock; runtime->private_data = dpcm; runtime->private_free = loopback_runtime_free; if (get_notify(dpcm)) runtime->hw = loopback_pcm_hardware; else runtime->hw = cable->hw; unlock: mutex_unlock(&loopback->cable_lock); return err; } static int loopback_close(struct snd_pcm_substream *substream) { struct loopback *loopback = substream->private_data; struct loopback_pcm *dpcm = substream->runtime->private_data; struct loopback_cable *cable; int dev = get_cable_index(substream); loopback_timer_stop(dpcm); mutex_lock(&loopback->cable_lock); cable = loopback->cables[substream->number][dev]; if (cable->streams[!substream->stream]) { /* other stream is still alive */ cable->streams[substream->stream] = NULL; } else { /* free the cable */ loopback->cables[substream->number][dev] = NULL; kfree(cable); } mutex_unlock(&loopback->cable_lock); return 0; } static struct snd_pcm_ops loopback_playback_ops = { .open = loopback_open, .close = loopback_close, .ioctl = snd_pcm_lib_ioctl, .hw_params = loopback_hw_params, .hw_free = loopback_hw_free, .prepare = loopback_prepare, .trigger = loopback_trigger, .pointer = loopback_pointer, }; static struct snd_pcm_ops loopback_capture_ops = { .open = loopback_open, .close = loopback_close, .ioctl = snd_pcm_lib_ioctl, .hw_params = loopback_hw_params, .hw_free = loopback_hw_free, .prepare = loopback_prepare, .trigger = loopback_trigger, .pointer = loopback_pointer, }; static int __devinit loopback_pcm_new(struct loopback *loopback, int device, int substreams) { struct snd_pcm *pcm; int err; err = snd_pcm_new(loopback->card, "Loopback PCM", device, substreams, substreams, &pcm); if (err < 0) return err; snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_PLAYBACK, &loopback_playback_ops); snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_CAPTURE, &loopback_capture_ops); pcm->private_data = loopback; pcm->info_flags = 0; strcpy(pcm->name, "Loopback PCM"); loopback->pcm[device] = pcm; snd_pcm_lib_preallocate_pages_for_all(pcm, SNDRV_DMA_TYPE_CONTINUOUS, snd_dma_continuous_data(GFP_KERNEL), 0, 2 * 1024 * 1024); return 0; } static int loopback_rate_shift_info(struct snd_kcontrol *kcontrol, struct snd_ctl_elem_info *uinfo) { uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER; uinfo->count = 1; uinfo->value.integer.min = 80000; uinfo->value.integer.max = 120000; uinfo->value.integer.step = 1; return 0; } static int loopback_rate_shift_get(struct snd_kcontrol *kcontrol, struct snd_ctl_elem_value *ucontrol) { struct loopback *loopback = snd_kcontrol_chip(kcontrol); ucontrol->value.integer.value[0] = loopback->setup[kcontrol->id.subdevice] [kcontrol->id.device].rate_shift; return 0; } static int loopback_rate_shift_put(struct snd_kcontrol *kcontrol, struct snd_ctl_elem_value *ucontrol) { struct loopback *loopback = snd_kcontrol_chip(kcontrol); unsigned int val; int change = 0; val = ucontrol->value.integer.value[0]; if (val < 80000) val = 80000; if (val > 120000) val = 120000; mutex_lock(&loopback->cable_lock); if (val != loopback->setup[kcontrol->id.subdevice] [kcontrol->id.device].rate_shift) { loopback->setup[kcontrol->id.subdevice] [kcontrol->id.device].rate_shift = val; change = 1; } mutex_unlock(&loopback->cable_lock); return change; } static int loopback_notify_get(struct snd_kcontrol *kcontrol, struct snd_ctl_elem_value *ucontrol) { struct loopback *loopback = snd_kcontrol_chip(kcontrol); ucontrol->value.integer.value[0] = loopback->setup[kcontrol->id.subdevice] [kcontrol->id.device].notify; return 0; } static int loopback_notify_put(struct snd_kcontrol *kcontrol, struct snd_ctl_elem_value *ucontrol) { struct loopback *loopback = snd_kcontrol_chip(kcontrol); unsigned int val; int change = 0; val = ucontrol->value.integer.value[0] ? 1 : 0; if (val != loopback->setup[kcontrol->id.subdevice] [kcontrol->id.device].notify) { loopback->setup[kcontrol->id.subdevice] [kcontrol->id.device].notify = val; change = 1; } return change; } static int loopback_active_get(struct snd_kcontrol *kcontrol, struct snd_ctl_elem_value *ucontrol) { struct loopback *loopback = snd_kcontrol_chip(kcontrol); struct loopback_cable *cable = loopback->cables [kcontrol->id.subdevice][kcontrol->id.device ^ 1]; unsigned int val = 0; if (cable != NULL) val = (cable->running & (1 << SNDRV_PCM_STREAM_PLAYBACK)) ? 1 : 0; ucontrol->value.integer.value[0] = val; return 0; } static int loopback_format_info(struct snd_kcontrol *kcontrol, struct snd_ctl_elem_info *uinfo) { uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER; uinfo->count = 1; uinfo->value.integer.min = 0; uinfo->value.integer.max = SNDRV_PCM_FORMAT_LAST; uinfo->value.integer.step = 1; return 0; } static int loopback_format_get(struct snd_kcontrol *kcontrol, struct snd_ctl_elem_value *ucontrol) { struct loopback *loopback = snd_kcontrol_chip(kcontrol); ucontrol->value.integer.value[0] = loopback->setup[kcontrol->id.subdevice] [kcontrol->id.device].format; return 0; } static int loopback_rate_info(struct snd_kcontrol *kcontrol, struct snd_ctl_elem_info *uinfo) { uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER; uinfo->count = 1; uinfo->value.integer.min = 0; uinfo->value.integer.max = 192000; uinfo->value.integer.step = 1; return 0; } static int loopback_rate_get(struct snd_kcontrol *kcontrol, struct snd_ctl_elem_value *ucontrol) { struct loopback *loopback = snd_kcontrol_chip(kcontrol); ucontrol->value.integer.value[0] = loopback->setup[kcontrol->id.subdevice] [kcontrol->id.device].rate; return 0; } static int loopback_channels_info(struct snd_kcontrol *kcontrol, struct snd_ctl_elem_info *uinfo) { uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER; uinfo->count = 1; uinfo->value.integer.min = 1; uinfo->value.integer.max = 1024; uinfo->value.integer.step = 1; return 0; } static int loopback_channels_get(struct snd_kcontrol *kcontrol, struct snd_ctl_elem_value *ucontrol) { struct loopback *loopback = snd_kcontrol_chip(kcontrol); ucontrol->value.integer.value[0] = loopback->setup[kcontrol->id.subdevice] [kcontrol->id.device].channels; return 0; } static struct snd_kcontrol_new loopback_controls[] __devinitdata = { { .iface = SNDRV_CTL_ELEM_IFACE_PCM, .name = "PCM Rate Shift 100000", .info = loopback_rate_shift_info, .get = loopback_rate_shift_get, .put = loopback_rate_shift_put, }, { .iface = SNDRV_CTL_ELEM_IFACE_PCM, .name = "PCM Notify", .info = snd_ctl_boolean_mono_info, .get = loopback_notify_get, .put = loopback_notify_put, }, #define ACTIVE_IDX 2 { .access = SNDRV_CTL_ELEM_ACCESS_READ, .iface = SNDRV_CTL_ELEM_IFACE_PCM, .name = "PCM Slave Active", .info = snd_ctl_boolean_mono_info, .get = loopback_active_get, }, #define FORMAT_IDX 3 { .access = SNDRV_CTL_ELEM_ACCESS_READ, .iface = SNDRV_CTL_ELEM_IFACE_PCM, .name = "PCM Slave Format", .info = loopback_format_info, .get = loopback_format_get }, #define RATE_IDX 4 { .access = SNDRV_CTL_ELEM_ACCESS_READ, .iface = SNDRV_CTL_ELEM_IFACE_PCM, .name = "PCM Slave Rate", .info = loopback_rate_info, .get = loopback_rate_get }, #define CHANNELS_IDX 5 { .access = SNDRV_CTL_ELEM_ACCESS_READ, .iface = SNDRV_CTL_ELEM_IFACE_PCM, .name = "PCM Slave Channels", .info = loopback_channels_info, .get = loopback_channels_get } }; static int __devinit loopback_mixer_new(struct loopback *loopback, int notify) { struct snd_card *card = loopback->card; struct snd_pcm *pcm; struct snd_kcontrol *kctl; struct loopback_setup *setup; int err, dev, substr, substr_count, idx; strcpy(card->mixername, "Loopback Mixer"); for (dev = 0; dev < 2; dev++) { pcm = loopback->pcm[dev]; substr_count = pcm->streams[SNDRV_PCM_STREAM_CAPTURE].substream_count; for (substr = 0; substr < substr_count; substr++) { setup = &loopback->setup[substr][dev]; setup->notify = notify; setup->rate_shift = NO_PITCH; setup->format = SNDRV_PCM_FORMAT_S16_LE; setup->rate = 48000; setup->channels = 2; for (idx = 0; idx < ARRAY_SIZE(loopback_controls); idx++) { kctl = snd_ctl_new1(&loopback_controls[idx], loopback); if (!kctl) return -ENOMEM; kctl->id.device = dev; kctl->id.subdevice = substr; switch (idx) { case ACTIVE_IDX: setup->active_id = kctl->id; break; case FORMAT_IDX: setup->format_id = kctl->id; break; case RATE_IDX: setup->rate_id = kctl->id; break; case CHANNELS_IDX: setup->channels_id = kctl->id; break; default: break; } err = snd_ctl_add(card, kctl); if (err < 0) return err; } } } return 0; } #ifdef CONFIG_PROC_FS static void print_dpcm_info(struct snd_info_buffer *buffer, struct loopback_pcm *dpcm, const char *id) { snd_iprintf(buffer, " %s\n", id); if (dpcm == NULL) { snd_iprintf(buffer, " inactive\n"); return; } snd_iprintf(buffer, " buffer_size:\t%u\n", dpcm->pcm_buffer_size); snd_iprintf(buffer, " buffer_pos:\t\t%u\n", dpcm->buf_pos); snd_iprintf(buffer, " silent_size:\t%u\n", dpcm->silent_size); snd_iprintf(buffer, " period_size:\t%u\n", dpcm->pcm_period_size); snd_iprintf(buffer, " bytes_per_sec:\t%u\n", dpcm->pcm_bps); snd_iprintf(buffer, " sample_align:\t%u\n", dpcm->pcm_salign); snd_iprintf(buffer, " rate_shift:\t\t%u\n", dpcm->pcm_rate_shift); snd_iprintf(buffer, " update_pending:\t%u\n", dpcm->period_update_pending); snd_iprintf(buffer, " irq_pos:\t\t%u\n", dpcm->irq_pos); snd_iprintf(buffer, " period_frac:\t%u\n", dpcm->period_size_frac); snd_iprintf(buffer, " last_jiffies:\t%lu (%lu)\n", dpcm->last_jiffies, jiffies); snd_iprintf(buffer, " timer_expires:\t%lu\n", dpcm->timer.expires); } static void print_substream_info(struct snd_info_buffer *buffer, struct loopback *loopback, int sub, int num) { struct loopback_cable *cable = loopback->cables[sub][num]; snd_iprintf(buffer, "Cable %i substream %i:\n", num, sub); if (cable == NULL) { snd_iprintf(buffer, " inactive\n"); return; } snd_iprintf(buffer, " valid: %u\n", cable->valid); snd_iprintf(buffer, " running: %u\n", cable->running); print_dpcm_info(buffer, cable->streams[0], "Playback"); print_dpcm_info(buffer, cable->streams[1], "Capture"); } static void print_cable_info(struct snd_info_entry *entry, struct snd_info_buffer *buffer) { struct loopback *loopback = entry->private_data; int sub, num; mutex_lock(&loopback->cable_lock); num = entry->name[strlen(entry->name)-1]; num = num == '0' ? 0 : 1; for (sub = 0; sub < MAX_PCM_SUBSTREAMS; sub++) print_substream_info(buffer, loopback, sub, num); mutex_unlock(&loopback->cable_lock); } static int __devinit loopback_proc_new(struct loopback *loopback, int cidx) { char name[32]; struct snd_info_entry *entry; int err; snprintf(name, sizeof(name), "cable#%d", cidx); err = snd_card_proc_new(loopback->card, name, &entry); if (err < 0) return err; snd_info_set_text_ops(entry, loopback, print_cable_info); return 0; } #else /* !CONFIG_PROC_FS */ #define loopback_proc_new(loopback, cidx) do { } while (0) #endif static int __devinit loopback_probe(struct platform_device *devptr) { struct snd_card *card; struct loopback *loopback; int dev = devptr->id; int err; err = snd_card_create(index[dev], id[dev], THIS_MODULE, sizeof(struct loopback), &card); if (err < 0) return err; loopback = card->private_data; if (pcm_substreams[dev] < 1) pcm_substreams[dev] = 1; if (pcm_substreams[dev] > MAX_PCM_SUBSTREAMS) pcm_substreams[dev] = MAX_PCM_SUBSTREAMS; loopback->card = card; mutex_init(&loopback->cable_lock); err = loopback_pcm_new(loopback, 0, pcm_substreams[dev]); if (err < 0) goto __nodev; err = loopback_pcm_new(loopback, 1, pcm_substreams[dev]); if (err < 0) goto __nodev; err = loopback_mixer_new(loopback, pcm_notify[dev] ? 1 : 0); if (err < 0) goto __nodev; loopback_proc_new(loopback, 0); loopback_proc_new(loopback, 1); strcpy(card->driver, "Loopback"); strcpy(card->shortname, "Loopback"); sprintf(card->longname, "Loopback %i", dev + 1); err = snd_card_register(card); if (!err) { platform_set_drvdata(devptr, card); return 0; } __nodev: snd_card_free(card); return err; } static int __devexit loopback_remove(struct platform_device *devptr) { snd_card_free(platform_get_drvdata(devptr)); platform_set_drvdata(devptr, NULL); return 0; } #ifdef CONFIG_PM static int loopback_suspend(struct platform_device *pdev, pm_message_t state) { struct snd_card *card = platform_get_drvdata(pdev); struct loopback *loopback = card->private_data; snd_power_change_state(card, SNDRV_CTL_POWER_D3hot); snd_pcm_suspend_all(loopback->pcm[0]); snd_pcm_suspend_all(loopback->pcm[1]); return 0; } static int loopback_resume(struct platform_device *pdev) { struct snd_card *card = platform_get_drvdata(pdev); snd_power_change_state(card, SNDRV_CTL_POWER_D0); return 0; } #endif #define SND_LOOPBACK_DRIVER "snd_aloop" static struct platform_driver loopback_driver = { .probe = loopback_probe, .remove = __devexit_p(loopback_remove), #ifdef CONFIG_PM .suspend = loopback_suspend, .resume = loopback_resume, #endif .driver = { .name = SND_LOOPBACK_DRIVER }, }; static void loopback_unregister_all(void) { int i; for (i = 0; i < ARRAY_SIZE(devices); ++i) platform_device_unregister(devices[i]); platform_driver_unregister(&loopback_driver); } static int __init alsa_card_loopback_init(void) { int i, err, cards; err = platform_driver_register(&loopback_driver); if (err < 0) return err; cards = 0; for (i = 0; i < SNDRV_CARDS; i++) { struct platform_device *device; if (!enable[i]) continue; device = platform_device_register_simple(SND_LOOPBACK_DRIVER, i, NULL, 0); if (IS_ERR(device)) continue; if (!platform_get_drvdata(device)) { platform_device_unregister(device); continue; } devices[i] = device; cards++; } if (!cards) { #ifdef MODULE printk(KERN_ERR "aloop: No loopback enabled\n"); #endif loopback_unregister_all(); return -ENODEV; } return 0; } static void __exit alsa_card_loopback_exit(void) { loopback_unregister_all(); } module_init(alsa_card_loopback_init) module_exit(alsa_card_loopback_exit)