| Author | Tokens | Token Proportion | Commits | Commit Proportion |
|---|---|---|---|---|
| Jaroslav Kysela | 5830 | 60.60% | 10 | 17.24% |
| Timo Wischer | 2778 | 28.88% | 7 | 12.07% |
| Ivan Orlov | 351 | 3.65% | 2 | 3.45% |
| Takashi Iwai | 348 | 3.62% | 22 | 37.93% |
| Andrew Gabbasov | 209 | 2.17% | 4 | 6.90% |
| Chancel Liu | 49 | 0.51% | 1 | 1.72% |
| Robert Rosengren | 18 | 0.19% | 1 | 1.72% |
| Kees Cook | 12 | 0.12% | 1 | 1.72% |
| Pattara Teerapong | 8 | 0.08% | 1 | 1.72% |
| Lars-Peter Clausen | 4 | 0.04% | 1 | 1.72% |
| Rikard Falkeborn | 3 | 0.03% | 1 | 1.72% |
| Eldad Zack | 3 | 0.03% | 1 | 1.72% |
| Thomas Gleixner | 2 | 0.02% | 1 | 1.72% |
| Paul Gortmaker | 1 | 0.01% | 1 | 1.72% |
| Baolin Wang | 1 | 0.01% | 1 | 1.72% |
| Jonas Holmberg | 1 | 0.01% | 1 | 1.72% |
| Arvind Yadav | 1 | 0.01% | 1 | 1.72% |
| Rusty Russell | 1 | 0.01% | 1 | 1.72% |
| Total | 9620 | 58 |
// SPDX-License-Identifier: GPL-2.0-or-later /* * Loopback soundcard * * Original code: * Copyright (c) by Jaroslav Kysela <perex@perex.cz> * * More accurate positioning and full-duplex support: * Copyright (c) Ahmet İnan <ainan at mathematik.uni-freiburg.de> * * Major (almost complete) rewrite: * Copyright (c) by Takashi Iwai <tiwai@suse.de> * * A next major update in 2010 (separate timers for playback and capture): * Copyright (c) Jaroslav Kysela <perex@perex.cz> */ #include <linux/init.h> #include <linux/jiffies.h> #include <linux/slab.h> #include <linux/time.h> #include <linux/wait.h> #include <linux/module.h> #include <linux/platform_device.h> #include <sound/core.h> #include <sound/control.h> #include <sound/pcm.h> #include <sound/pcm_params.h> #include <sound/info.h> #include <sound/initval.h> #include <sound/timer.h> MODULE_AUTHOR("Jaroslav Kysela <perex@perex.cz>"); MODULE_DESCRIPTION("A loopback soundcard"); MODULE_LICENSE("GPL"); #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 bool 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]; static char *timer_source[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."); module_param_array(timer_source, charp, NULL, 0444); MODULE_PARM_DESC(timer_source, "Sound card name or number and device/subdevice number of timer to be used. Empty string for jiffies timer [default]."); #define NO_PITCH 100000 #define CABLE_VALID_PLAYBACK BIT(SNDRV_PCM_STREAM_PLAYBACK) #define CABLE_VALID_CAPTURE BIT(SNDRV_PCM_STREAM_CAPTURE) #define CABLE_VALID_BOTH (CABLE_VALID_PLAYBACK | CABLE_VALID_CAPTURE) struct loopback_cable; struct loopback_pcm; struct loopback_ops { /* optional * call in loopback->cable_lock */ int (*open)(struct loopback_pcm *dpcm); /* required * call in cable->lock */ int (*start)(struct loopback_pcm *dpcm); /* required * call in cable->lock */ int (*stop)(struct loopback_pcm *dpcm); /* optional */ int (*stop_sync)(struct loopback_pcm *dpcm); /* optional */ int (*close_substream)(struct loopback_pcm *dpcm); /* optional * call in loopback->cable_lock */ int (*close_cable)(struct loopback_pcm *dpcm); /* optional * call in cable->lock */ unsigned int (*pos_update)(struct loopback_cable *cable); /* optional */ void (*dpcm_info)(struct loopback_pcm *dpcm, struct snd_info_buffer *buffer); }; struct loopback_cable { spinlock_t lock; struct loopback_pcm *streams[2]; struct snd_pcm_hardware hw; /* flags */ unsigned int valid; unsigned int running; unsigned int pause; /* timer specific */ const struct loopback_ops *ops; /* If sound timer is used */ struct { int stream; struct snd_timer_id id; struct work_struct event_work; struct snd_timer_instance *instance; } snd_timer; }; struct loopback_setup { unsigned int notify: 1; unsigned int rate_shift; snd_pcm_format_t format; unsigned int rate; snd_pcm_access_t access; 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 snd_ctl_elem_id access_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]; const char *timer_source; }; 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 in jiffies * ticks */ unsigned int period_size_frac; /* period size in jiffies ticks */ unsigned int last_drift; unsigned long last_jiffies; /* If jiffies timer is used */ struct timer_list timer; /* size of per channel buffer in case of non-interleaved access */ unsigned int channel_buf_n; }; 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; } /* call in cable->lock */ static int loopback_jiffies_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 = DIV_ROUND_UP(tick, dpcm->pcm_bps); mod_timer(&dpcm->timer, jiffies + tick); return 0; } /* call in cable->lock */ static int loopback_snd_timer_start(struct loopback_pcm *dpcm) { struct loopback_cable *cable = dpcm->cable; int err; /* Loopback device has to use same period as timer card. Therefore * wake up for each snd_pcm_period_elapsed() call of timer card. */ err = snd_timer_start(cable->snd_timer.instance, 1); if (err < 0) { /* do not report error if trying to start but already * running. For example called by opposite substream * of the same cable */ if (err == -EBUSY) return 0; pcm_err(dpcm->substream->pcm, "snd_timer_start(%d,%d,%d) failed with %d", cable->snd_timer.id.card, cable->snd_timer.id.device, cable->snd_timer.id.subdevice, err); } return err; } /* call in cable->lock */ static inline int loopback_jiffies_timer_stop(struct loopback_pcm *dpcm) { del_timer(&dpcm->timer); dpcm->timer.expires = 0; return 0; } /* call in cable->lock */ static int loopback_snd_timer_stop(struct loopback_pcm *dpcm) { struct loopback_cable *cable = dpcm->cable; int err; /* only stop if both devices (playback and capture) are not running */ if (cable->running ^ cable->pause) return 0; err = snd_timer_stop(cable->snd_timer.instance); if (err < 0) { pcm_err(dpcm->substream->pcm, "snd_timer_stop(%d,%d,%d) failed with %d", cable->snd_timer.id.card, cable->snd_timer.id.device, cable->snd_timer.id.subdevice, err); } return err; } static inline int loopback_jiffies_timer_stop_sync(struct loopback_pcm *dpcm) { del_timer_sync(&dpcm->timer); return 0; } /* call in loopback->cable_lock */ static int loopback_snd_timer_close_cable(struct loopback_pcm *dpcm) { struct loopback_cable *cable = dpcm->cable; /* snd_timer was not opened */ if (!cable->snd_timer.instance) return 0; /* will only be called from free_cable() when other stream was * already closed. Other stream cannot be reopened as long as * loopback->cable_lock is locked. Therefore no need to lock * cable->lock; */ snd_timer_close(cable->snd_timer.instance); /* wait till drain work has finished if requested */ cancel_work_sync(&cable->snd_timer.event_work); snd_timer_instance_free(cable->snd_timer.instance); memset(&cable->snd_timer, 0, sizeof(cable->snd_timer)); return 0; } static bool is_access_interleaved(snd_pcm_access_t access) { switch (access) { case SNDRV_PCM_ACCESS_MMAP_INTERLEAVED: case SNDRV_PCM_ACCESS_RW_INTERLEAVED: return true; default: return false; } }; 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 || is_access_interleaved(runtime->access) != is_access_interleaved(cruntime->access); 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; } if (is_access_interleaved(setup->access) != is_access_interleaved(runtime->access)) { snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_VALUE, &setup->access_id); setup->access = runtime->access; } } 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 = 0, stream = 1 << substream->stream; 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; dpcm->last_drift = 0; spin_lock(&cable->lock); cable->running |= stream; cable->pause &= ~stream; err = cable->ops->start(dpcm); spin_unlock(&cable->lock); if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) loopback_active_notify(dpcm); break; case SNDRV_PCM_TRIGGER_STOP: spin_lock(&cable->lock); cable->running &= ~stream; cable->pause &= ~stream; err = cable->ops->stop(dpcm); spin_unlock(&cable->lock); if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) loopback_active_notify(dpcm); break; case SNDRV_PCM_TRIGGER_PAUSE_PUSH: case SNDRV_PCM_TRIGGER_SUSPEND: spin_lock(&cable->lock); cable->pause |= stream; err = cable->ops->stop(dpcm); spin_unlock(&cable->lock); if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) loopback_active_notify(dpcm); break; case SNDRV_PCM_TRIGGER_PAUSE_RELEASE: case SNDRV_PCM_TRIGGER_RESUME: spin_lock(&cable->lock); dpcm->last_jiffies = jiffies; cable->pause &= ~stream; err = cable->ops->start(dpcm); spin_unlock(&cable->lock); if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) loopback_active_notify(dpcm); break; default: return -EINVAL; } return err; } 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 = pcm_format_to_bits(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; if (cable->snd_timer.instance) { cable->hw.period_bytes_min = frames_to_bytes(runtime, runtime->period_size); cable->hw.period_bytes_max = cable->hw.period_bytes_min; } } 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 err, bps, salign; if (cable->ops->stop_sync) { err = cable->ops->stop_sync(dpcm); if (err < 0) return err; } salign = (snd_pcm_format_physical_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); dpcm->channel_buf_n = dpcm->pcm_buffer_size / runtime->channels; 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_part_n(struct loopback_pcm *play, struct loopback_pcm *capt, unsigned int size, unsigned int src_off, unsigned int dst_off) { unsigned int channels = capt->substream->runtime->channels; unsigned int size_p_ch = size / channels; unsigned int src_off_ch = src_off / channels; unsigned int dst_off_ch = dst_off / channels; int i; for (i = 0; i < channels; i++) { memcpy(capt->substream->runtime->dma_area + capt->channel_buf_n * i + dst_off_ch, play->substream->runtime->dma_area + play->channel_buf_n * i + src_off_ch, size_p_ch); } } 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->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; if (!is_access_interleaved(runtime->access)) copy_play_buf_part_n(play, capt, size, src_off, dst_off); else 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; } } static inline unsigned int bytepos_delta(struct loopback_pcm *dpcm, unsigned int jiffies_delta) { unsigned long last_pos; unsigned int delta; last_pos = byte_pos(dpcm, dpcm->irq_pos); dpcm->irq_pos += jiffies_delta * dpcm->pcm_bps; delta = byte_pos(dpcm, dpcm->irq_pos) - last_pos; if (delta >= dpcm->last_drift) delta -= dpcm->last_drift; dpcm->last_drift = 0; if (dpcm->irq_pos >= dpcm->period_size_frac) { dpcm->irq_pos %= dpcm->period_size_frac; dpcm->period_update_pending = 1; } return delta; } static inline void bytepos_finish(struct loopback_pcm *dpcm, unsigned int delta) { dpcm->buf_pos += delta; dpcm->buf_pos %= dpcm->pcm_buffer_size; } /* call in cable->lock */ static unsigned int loopback_jiffies_timer_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, cur_jiffies; unsigned int running, count1, count2; cur_jiffies = jiffies; running = cable->running ^ cable->pause; if (running & (1 << SNDRV_PCM_STREAM_PLAYBACK)) { delta_play = cur_jiffies - dpcm_play->last_jiffies; dpcm_play->last_jiffies += delta_play; } if (running & (1 << SNDRV_PCM_STREAM_CAPTURE)) { delta_capt = cur_jiffies - dpcm_capt->last_jiffies; dpcm_capt->last_jiffies += delta_capt; } if (delta_play == 0 && delta_capt == 0) goto unlock; if (delta_play > delta_capt) { count1 = bytepos_delta(dpcm_play, delta_play - delta_capt); bytepos_finish(dpcm_play, count1); delta_play = delta_capt; } else if (delta_play < delta_capt) { count1 = bytepos_delta(dpcm_capt, delta_capt - delta_play); clear_capture_buf(dpcm_capt, count1); bytepos_finish(dpcm_capt, count1); delta_capt = delta_play; } if (delta_play == 0 && delta_capt == 0) goto unlock; /* note delta_capt == delta_play at this moment */ count1 = bytepos_delta(dpcm_play, delta_play); count2 = bytepos_delta(dpcm_capt, delta_capt); if (count1 < count2) { dpcm_capt->last_drift = count2 - count1; count1 = count2; } else if (count1 > count2) { dpcm_play->last_drift = count1 - count2; } copy_play_buf(dpcm_play, dpcm_capt, count1); bytepos_finish(dpcm_play, count1); bytepos_finish(dpcm_capt, count1); unlock: return running; } static void loopback_jiffies_timer_function(struct timer_list *t) { struct loopback_pcm *dpcm = from_timer(dpcm, t, timer); unsigned long flags; spin_lock_irqsave(&dpcm->cable->lock, flags); if (loopback_jiffies_timer_pos_update(dpcm->cable) & (1 << dpcm->substream->stream)) { loopback_jiffies_timer_start(dpcm); if (dpcm->period_update_pending) { dpcm->period_update_pending = 0; spin_unlock_irqrestore(&dpcm->cable->lock, flags); /* need to unlock before calling below */ snd_pcm_period_elapsed(dpcm->substream); return; } } spin_unlock_irqrestore(&dpcm->cable->lock, flags); } /* call in cable->lock */ static int loopback_snd_timer_check_resolution(struct snd_pcm_runtime *runtime, unsigned long resolution) { if (resolution != runtime->timer_resolution) { struct loopback_pcm *dpcm = runtime->private_data; struct loopback_cable *cable = dpcm->cable; /* Worst case estimation of possible values for resolution * resolution <= (512 * 1024) frames / 8kHz in nsec * resolution <= 65.536.000.000 nsec * * period_size <= 65.536.000.000 nsec / 1000nsec/usec * 192kHz + * 500.000 * period_size <= 12.582.912.000.000 <64bit * / 1.000.000 usec/sec */ snd_pcm_uframes_t period_size_usec = resolution / 1000 * runtime->rate; /* round to nearest sample rate */ snd_pcm_uframes_t period_size = (period_size_usec + 500 * 1000) / (1000 * 1000); pcm_err(dpcm->substream->pcm, "Period size (%lu frames) of loopback device is not corresponding to timer resolution (%lu nsec = %lu frames) of card timer %d,%d,%d. Use period size of %lu frames for loopback device.", runtime->period_size, resolution, period_size, cable->snd_timer.id.card, cable->snd_timer.id.device, cable->snd_timer.id.subdevice, period_size); return -EINVAL; } return 0; } static void loopback_snd_timer_period_elapsed(struct loopback_cable *cable, int event, unsigned long resolution) { struct loopback_pcm *dpcm_play, *dpcm_capt; struct snd_pcm_substream *substream_play, *substream_capt; struct snd_pcm_runtime *valid_runtime; unsigned int running, elapsed_bytes; unsigned long flags; spin_lock_irqsave(&cable->lock, flags); running = cable->running ^ cable->pause; /* no need to do anything if no stream is running */ if (!running) { spin_unlock_irqrestore(&cable->lock, flags); return; } dpcm_play = cable->streams[SNDRV_PCM_STREAM_PLAYBACK]; dpcm_capt = cable->streams[SNDRV_PCM_STREAM_CAPTURE]; if (event == SNDRV_TIMER_EVENT_MSTOP) { if (!dpcm_play || dpcm_play->substream->runtime->state != SNDRV_PCM_STATE_DRAINING) { spin_unlock_irqrestore(&cable->lock, flags); return; } } substream_play = (running & (1 << SNDRV_PCM_STREAM_PLAYBACK)) ? dpcm_play->substream : NULL; substream_capt = (running & (1 << SNDRV_PCM_STREAM_CAPTURE)) ? dpcm_capt->substream : NULL; valid_runtime = (running & (1 << SNDRV_PCM_STREAM_PLAYBACK)) ? dpcm_play->substream->runtime : dpcm_capt->substream->runtime; /* resolution is only valid for SNDRV_TIMER_EVENT_TICK events */ if (event == SNDRV_TIMER_EVENT_TICK) { /* The hardware rules guarantee that playback and capture period * are the same. Therefore only one device has to be checked * here. */ if (loopback_snd_timer_check_resolution(valid_runtime, resolution) < 0) { spin_unlock_irqrestore(&cable->lock, flags); if (substream_play) snd_pcm_stop_xrun(substream_play); if (substream_capt) snd_pcm_stop_xrun(substream_capt); return; } } elapsed_bytes = frames_to_bytes(valid_runtime, valid_runtime->period_size); /* The same timer interrupt is used for playback and capture device */ if ((running & (1 << SNDRV_PCM_STREAM_PLAYBACK)) && (running & (1 << SNDRV_PCM_STREAM_CAPTURE))) { copy_play_buf(dpcm_play, dpcm_capt, elapsed_bytes); bytepos_finish(dpcm_play, elapsed_bytes); bytepos_finish(dpcm_capt, elapsed_bytes); } else if (running & (1 << SNDRV_PCM_STREAM_PLAYBACK)) { bytepos_finish(dpcm_play, elapsed_bytes); } else if (running & (1 << SNDRV_PCM_STREAM_CAPTURE)) { clear_capture_buf(dpcm_capt, elapsed_bytes); bytepos_finish(dpcm_capt, elapsed_bytes); } spin_unlock_irqrestore(&cable->lock, flags); if (substream_play) snd_pcm_period_elapsed(substream_play); if (substream_capt) snd_pcm_period_elapsed(substream_capt); } static void loopback_snd_timer_function(struct snd_timer_instance *timeri, unsigned long resolution, unsigned long ticks) { struct loopback_cable *cable = timeri->callback_data; loopback_snd_timer_period_elapsed(cable, SNDRV_TIMER_EVENT_TICK, resolution); } static void loopback_snd_timer_work(struct work_struct *work) { struct loopback_cable *cable; cable = container_of(work, struct loopback_cable, snd_timer.event_work); loopback_snd_timer_period_elapsed(cable, SNDRV_TIMER_EVENT_MSTOP, 0); } static void loopback_snd_timer_event(struct snd_timer_instance *timeri, int event, struct timespec64 *tstamp, unsigned long resolution) { /* Do not lock cable->lock here because timer->lock is already hold. * There are other functions which first lock cable->lock and than * timer->lock e.g. * loopback_trigger() * spin_lock(&cable->lock) * loopback_snd_timer_start() * snd_timer_start() * spin_lock(&timer->lock) * Therefore when using the oposit order of locks here it could result * in a deadlock. */ if (event == SNDRV_TIMER_EVENT_MSTOP) { struct loopback_cable *cable = timeri->callback_data; /* sound card of the timer was stopped. Therefore there will not * be any further timer callbacks. Due to this forward audio * data from here if in draining state. When still in running * state the streaming will be aborted by the usual timeout. It * should not be aborted here because may be the timer sound * card does only a recovery and the timer is back soon. * This work triggers loopback_snd_timer_work() */ schedule_work(&cable->snd_timer.event_work); } } static void loopback_jiffies_timer_dpcm_info(struct loopback_pcm *dpcm, struct snd_info_buffer *buffer) { 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 loopback_snd_timer_dpcm_info(struct loopback_pcm *dpcm, struct snd_info_buffer *buffer) { struct loopback_cable *cable = dpcm->cable; snd_iprintf(buffer, " sound timer:\thw:%d,%d,%d\n", cable->snd_timer.id.card, cable->snd_timer.id.device, cable->snd_timer.id.subdevice); snd_iprintf(buffer, " timer open:\t\t%s\n", (cable->snd_timer.stream == SNDRV_PCM_STREAM_CAPTURE) ? "capture" : "playback"); } 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; snd_pcm_uframes_t pos; spin_lock(&dpcm->cable->lock); if (dpcm->cable->ops->pos_update) dpcm->cable->ops->pos_update(dpcm->cable); pos = dpcm->buf_pos; spin_unlock(&dpcm->cable->lock); return bytes_to_frames(runtime, pos); } static const struct snd_pcm_hardware loopback_pcm_hardware = { .info = (SNDRV_PCM_INFO_INTERLEAVED | SNDRV_PCM_INFO_MMAP | SNDRV_PCM_INFO_MMAP_VALID | SNDRV_PCM_INFO_PAUSE | SNDRV_PCM_INFO_RESUME | SNDRV_PCM_INFO_NONINTERLEAVED), .formats = (SNDRV_PCM_FMTBIT_S16_LE | SNDRV_PCM_FMTBIT_S16_BE | SNDRV_PCM_FMTBIT_S24_LE | SNDRV_PCM_FMTBIT_S24_BE | SNDRV_PCM_FMTBIT_S24_3LE | SNDRV_PCM_FMTBIT_S24_3BE | 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_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 0; } 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 loopback_pcm *dpcm = rule->private; struct loopback_cable *cable = dpcm->cable; struct snd_mask m; snd_mask_none(&m); mutex_lock(&dpcm->loopback->cable_lock); m.bits[0] = (u_int32_t)cable->hw.formats; m.bits[1] = (u_int32_t)(cable->hw.formats >> 32); mutex_unlock(&dpcm->loopback->cable_lock); return snd_mask_refine(hw_param_mask(params, rule->var), &m); } static int rule_rate(struct snd_pcm_hw_params *params, struct snd_pcm_hw_rule *rule) { struct loopback_pcm *dpcm = rule->private; struct loopback_cable *cable = dpcm->cable; struct snd_interval t; mutex_lock(&dpcm->loopback->cable_lock); t.min = cable->hw.rate_min; t.max = cable->hw.rate_max; mutex_unlock(&dpcm->loopback->cable_lock); 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 loopback_pcm *dpcm = rule->private; struct loopback_cable *cable = dpcm->cable; struct snd_interval t; mutex_lock(&dpcm->loopback->cable_lock); t.min = cable->hw.channels_min; t.max = cable->hw.channels_max; mutex_unlock(&dpcm->loopback->cable_lock); t.openmin = t.openmax = 0; t.integer = 0; return snd_interval_refine(hw_param_interval(params, rule->var), &t); } static int rule_period_bytes(struct snd_pcm_hw_params *params, struct snd_pcm_hw_rule *rule) { struct loopback_pcm *dpcm = rule->private; struct loopback_cable *cable = dpcm->cable; struct snd_interval t; mutex_lock(&dpcm->loopback->cable_lock); t.min = cable->hw.period_bytes_min; t.max = cable->hw.period_bytes_max; mutex_unlock(&dpcm->loopback->cable_lock); t.openmin = 0; t.openmax = 0; t.integer = 0; return snd_interval_refine(hw_param_interval(params, rule->var), &t); } static void free_cable(struct snd_pcm_substream *substream) { struct loopback *loopback = substream->private_data; int dev = get_cable_index(substream); struct loopback_cable *cable; cable = loopback->cables[substream->number][dev]; if (!cable) return; if (cable->streams[!substream->stream]) { /* other stream is still alive */ spin_lock_irq(&cable->lock); cable->streams[substream->stream] = NULL; spin_unlock_irq(&cable->lock); } else { struct loopback_pcm *dpcm = substream->runtime->private_data; if (cable->ops && cable->ops->close_cable && dpcm) cable->ops->close_cable(dpcm); /* free the cable */ loopback->cables[substream->number][dev] = NULL; kfree(cable); } } static int loopback_jiffies_timer_open(struct loopback_pcm *dpcm) { timer_setup(&dpcm->timer, loopback_jiffies_timer_function, 0); return 0; } static const struct loopback_ops loopback_jiffies_timer_ops = { .open = loopback_jiffies_timer_open, .start = loopback_jiffies_timer_start, .stop = loopback_jiffies_timer_stop, .stop_sync = loopback_jiffies_timer_stop_sync, .close_substream = loopback_jiffies_timer_stop_sync, .pos_update = loopback_jiffies_timer_pos_update, .dpcm_info = loopback_jiffies_timer_dpcm_info, }; static int loopback_parse_timer_id(const char *str, struct snd_timer_id *tid) { /* [<pref>:](<card name>|<card idx>)[{.,}<dev idx>[{.,}<subdev idx>]] */ const char * const sep_dev = ".,"; const char * const sep_pref = ":"; const char *name = str; char *sep, save = '\0'; int card_idx = 0, dev = 0, subdev = 0; int err; sep = strpbrk(str, sep_pref); if (sep) name = sep + 1; sep = strpbrk(name, sep_dev); if (sep) { save = *sep; *sep = '\0'; } err = kstrtoint(name, 0, &card_idx); if (err == -EINVAL) { /* Must be the name, not number */ for (card_idx = 0; card_idx < snd_ecards_limit; card_idx++) { struct snd_card *card = snd_card_ref(card_idx); if (card) { if (!strcmp(card->id, name)) err = 0; snd_card_unref(card); } if (!err) break; } } if (sep) { *sep = save; if (!err) { char *sep2, save2 = '\0'; sep2 = strpbrk(sep + 1, sep_dev); if (sep2) { save2 = *sep2; *sep2 = '\0'; } err = kstrtoint(sep + 1, 0, &dev); if (sep2) { *sep2 = save2; if (!err) err = kstrtoint(sep2 + 1, 0, &subdev); } } } if (!err && tid) { tid->card = card_idx; tid->device = dev; tid->subdevice = subdev; } return err; } /* call in loopback->cable_lock */ static int loopback_snd_timer_open(struct loopback_pcm *dpcm) { int err = 0; struct snd_timer_id tid = { .dev_class = SNDRV_TIMER_CLASS_PCM, .dev_sclass = SNDRV_TIMER_SCLASS_APPLICATION, }; struct snd_timer_instance *timeri; struct loopback_cable *cable = dpcm->cable; /* check if timer was already opened. It is only opened once * per playback and capture subdevice (aka cable). */ if (cable->snd_timer.instance) goto exit; err = loopback_parse_timer_id(dpcm->loopback->timer_source, &tid); if (err < 0) { pcm_err(dpcm->substream->pcm, "Parsing timer source \'%s\' failed with %d", dpcm->loopback->timer_source, err); goto exit; } cable->snd_timer.stream = dpcm->substream->stream; cable->snd_timer.id = tid; timeri = snd_timer_instance_new(dpcm->loopback->card->id); if (!timeri) { err = -ENOMEM; goto exit; } /* The callback has to be called from another work. If * SNDRV_TIMER_IFLG_FAST is specified it will be called from the * snd_pcm_period_elapsed() call of the selected sound card. * snd_pcm_period_elapsed() helds snd_pcm_stream_lock_irqsave(). * Due to our callback loopback_snd_timer_function() also calls * snd_pcm_period_elapsed() which calls snd_pcm_stream_lock_irqsave(). * This would end up in a dead lock. */ timeri->flags |= SNDRV_TIMER_IFLG_AUTO; timeri->callback = loopback_snd_timer_function; timeri->callback_data = (void *)cable; timeri->ccallback = loopback_snd_timer_event; /* initialise a work used for draining */ INIT_WORK(&cable->snd_timer.event_work, loopback_snd_timer_work); /* The mutex loopback->cable_lock is kept locked. * Therefore snd_timer_open() cannot be called a second time * by the other device of the same cable. * Therefore the following issue cannot happen: * [proc1] Call loopback_timer_open() -> * Unlock cable->lock for snd_timer_close/open() call * [proc2] Call loopback_timer_open() -> snd_timer_open(), * snd_timer_start() * [proc1] Call snd_timer_open() and overwrite running timer * instance */ err = snd_timer_open(timeri, &cable->snd_timer.id, current->pid); if (err < 0) { pcm_err(dpcm->substream->pcm, "snd_timer_open (%d,%d,%d) failed with %d", cable->snd_timer.id.card, cable->snd_timer.id.device, cable->snd_timer.id.subdevice, err); snd_timer_instance_free(timeri); goto exit; } cable->snd_timer.instance = timeri; exit: return err; } /* stop_sync() is not required for sound timer because it does not need to be * restarted in loopback_prepare() on Xrun recovery */ static const struct loopback_ops loopback_snd_timer_ops = { .open = loopback_snd_timer_open, .start = loopback_snd_timer_start, .stop = loopback_snd_timer_stop, .close_cable = loopback_snd_timer_close_cable, .dpcm_info = loopback_snd_timer_dpcm_info, }; 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 = NULL; 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; cable = loopback->cables[substream->number][dev]; if (!cable) { cable = kzalloc(sizeof(*cable), GFP_KERNEL); if (!cable) { err = -ENOMEM; goto unlock; } spin_lock_init(&cable->lock); cable->hw = loopback_pcm_hardware; if (loopback->timer_source) cable->ops = &loopback_snd_timer_ops; else cable->ops = &loopback_jiffies_timer_ops; loopback->cables[substream->number][dev] = cable; } dpcm->cable = cable; runtime->private_data = dpcm; if (cable->ops->open) { err = cable->ops->open(dpcm); if (err < 0) goto unlock; } 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, dpcm, 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, dpcm, 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, dpcm, SNDRV_PCM_HW_PARAM_CHANNELS, -1); if (err < 0) goto unlock; /* In case of sound timer the period time of both devices of the same * loop has to be the same. * This rule only takes effect if a sound timer was chosen */ if (cable->snd_timer.instance) { err = snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_PERIOD_BYTES, rule_period_bytes, dpcm, SNDRV_PCM_HW_PARAM_PERIOD_BYTES, -1); if (err < 0) goto unlock; } /* loopback_runtime_free() has not to be called if kfree(dpcm) was * already called here. Otherwise it will end up with a double free. */ runtime->private_free = loopback_runtime_free; if (get_notify(dpcm)) runtime->hw = loopback_pcm_hardware; else runtime->hw = cable->hw; spin_lock_irq(&cable->lock); cable->streams[substream->stream] = dpcm; spin_unlock_irq(&cable->lock); unlock: if (err < 0) { free_cable(substream); kfree(dpcm); } 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; int err = 0; if (dpcm->cable->ops->close_substream) err = dpcm->cable->ops->close_substream(dpcm); mutex_lock(&loopback->cable_lock); free_cable(substream); mutex_unlock(&loopback->cable_lock); return err; } static const struct snd_pcm_ops loopback_pcm_ops = { .open = loopback_open, .close = loopback_close, .hw_free = loopback_hw_free, .prepare = loopback_prepare, .trigger = loopback_trigger, .pointer = loopback_pointer, }; static int 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_pcm_ops); snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_CAPTURE, &loopback_pcm_ops); snd_pcm_set_managed_buffer_all(pcm, SNDRV_DMA_TYPE_VMALLOC, NULL, 0, 0); pcm->private_data = loopback; pcm->info_flags = 0; strcpy(pcm->name, "Loopback PCM"); loopback->pcm[device] = pcm; 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); mutex_lock(&loopback->cable_lock); ucontrol->value.integer.value[0] = loopback->setup[kcontrol->id.subdevice] [kcontrol->id.device].rate_shift; mutex_unlock(&loopback->cable_lock); 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); mutex_lock(&loopback->cable_lock); ucontrol->value.integer.value[0] = loopback->setup[kcontrol->id.subdevice] [kcontrol->id.device].notify; mutex_unlock(&loopback->cable_lock); 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; mutex_lock(&loopback->cable_lock); if (val != loopback->setup[kcontrol->id.subdevice] [kcontrol->id.device].notify) { loopback->setup[kcontrol->id.subdevice] [kcontrol->id.device].notify = val; change = 1; } mutex_unlock(&loopback->cable_lock); 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; unsigned int val = 0; mutex_lock(&loopback->cable_lock); cable = loopback->cables[kcontrol->id.subdevice][kcontrol->id.device ^ 1]; if (cable != NULL) { unsigned int running = cable->running ^ cable->pause; val = (running & (1 << SNDRV_PCM_STREAM_PLAYBACK)) ? 1 : 0; } mutex_unlock(&loopback->cable_lock); 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 = (__force int)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] = (__force int)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); mutex_lock(&loopback->cable_lock); ucontrol->value.integer.value[0] = loopback->setup[kcontrol->id.subdevice] [kcontrol->id.device].rate; mutex_unlock(&loopback->cable_lock); 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); mutex_lock(&loopback->cable_lock); ucontrol->value.integer.value[0] = loopback->setup[kcontrol->id.subdevice] [kcontrol->id.device].channels; mutex_unlock(&loopback->cable_lock); return 0; } static int loopback_access_info(struct snd_kcontrol *kcontrol, struct snd_ctl_elem_info *uinfo) { const char * const texts[] = {"Interleaved", "Non-interleaved"}; return snd_ctl_enum_info(uinfo, 1, ARRAY_SIZE(texts), texts); } static int loopback_access_get(struct snd_kcontrol *kcontrol, struct snd_ctl_elem_value *ucontrol) { struct loopback *loopback = snd_kcontrol_chip(kcontrol); snd_pcm_access_t access; mutex_lock(&loopback->cable_lock); access = loopback->setup[kcontrol->id.subdevice][kcontrol->id.device].access; ucontrol->value.enumerated.item[0] = !is_access_interleaved(access); mutex_unlock(&loopback->cable_lock); return 0; } static const struct snd_kcontrol_new loopback_controls[] = { { .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 }, #define ACCESS_IDX 6 { .access = SNDRV_CTL_ELEM_ACCESS_READ, .iface = SNDRV_CTL_ELEM_IFACE_PCM, .name = "PCM Slave Access Mode", .info = loopback_access_info, .get = loopback_access_get, }, }; static int 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->access = SNDRV_PCM_ACCESS_RW_INTERLEAVED; 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; /* Add the control before copying the id so that * the numid field of the id is set in the copy. */ err = snd_ctl_add(card, kctl); if (err < 0) return err; 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; case ACCESS_IDX: setup->access_id = kctl->id; break; default: break; } } } } return 0; } 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); if (dpcm->cable->ops->dpcm_info) dpcm->cable->ops->dpcm_info(dpcm, buffer); } 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); snd_iprintf(buffer, " pause: %u\n", cable->pause); 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 loopback_cable_proc_new(struct loopback *loopback, int cidx) { char name[32]; snprintf(name, sizeof(name), "cable#%d", cidx); return snd_card_ro_proc_new(loopback->card, name, loopback, print_cable_info); } static void loopback_set_timer_source(struct loopback *loopback, const char *value) { if (loopback->timer_source) { devm_kfree(loopback->card->dev, loopback->timer_source); loopback->timer_source = NULL; } if (value && *value) loopback->timer_source = devm_kstrdup(loopback->card->dev, value, GFP_KERNEL); } static void print_timer_source_info(struct snd_info_entry *entry, struct snd_info_buffer *buffer) { struct loopback *loopback = entry->private_data; mutex_lock(&loopback->cable_lock); snd_iprintf(buffer, "%s\n", loopback->timer_source ? loopback->timer_source : ""); mutex_unlock(&loopback->cable_lock); } static void change_timer_source_info(struct snd_info_entry *entry, struct snd_info_buffer *buffer) { struct loopback *loopback = entry->private_data; char line[64]; mutex_lock(&loopback->cable_lock); if (!snd_info_get_line(buffer, line, sizeof(line))) loopback_set_timer_source(loopback, strim(line)); mutex_unlock(&loopback->cable_lock); } static int loopback_timer_source_proc_new(struct loopback *loopback) { return snd_card_rw_proc_new(loopback->card, "timer_source", loopback, print_timer_source_info, change_timer_source_info); } static int loopback_probe(struct platform_device *devptr) { struct snd_card *card; struct loopback *loopback; int dev = devptr->id; int err; err = snd_devm_card_new(&devptr->dev, 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; loopback_set_timer_source(loopback, timer_source[dev]); mutex_init(&loopback->cable_lock); err = loopback_pcm_new(loopback, 0, pcm_substreams[dev]); if (err < 0) return err; err = loopback_pcm_new(loopback, 1, pcm_substreams[dev]); if (err < 0) return err; err = loopback_mixer_new(loopback, pcm_notify[dev] ? 1 : 0); if (err < 0) return err; loopback_cable_proc_new(loopback, 0); loopback_cable_proc_new(loopback, 1); loopback_timer_source_proc_new(loopback); strcpy(card->driver, "Loopback"); strcpy(card->shortname, "Loopback"); sprintf(card->longname, "Loopback %i", dev + 1); err = snd_card_register(card); if (err < 0) return err; platform_set_drvdata(devptr, card); return 0; } static int loopback_suspend(struct device *pdev) { struct snd_card *card = dev_get_drvdata(pdev); snd_power_change_state(card, SNDRV_CTL_POWER_D3hot); return 0; } static int loopback_resume(struct device *pdev) { struct snd_card *card = dev_get_drvdata(pdev); snd_power_change_state(card, SNDRV_CTL_POWER_D0); return 0; } static DEFINE_SIMPLE_DEV_PM_OPS(loopback_pm, loopback_suspend, loopback_resume); #define SND_LOOPBACK_DRIVER "snd_aloop" static struct platform_driver loopback_driver = { .probe = loopback_probe, .driver = { .name = SND_LOOPBACK_DRIVER, .pm = &loopback_pm, }, }; 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)
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