| // 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 | |
| SNDRV_PCM_FMTBIT_DSD_U8 | |
| SNDRV_PCM_FMTBIT_DSD_U16_LE | SNDRV_PCM_FMTBIT_DSD_U16_BE | |
| SNDRV_PCM_FMTBIT_DSD_U32_LE | SNDRV_PCM_FMTBIT_DSD_U32_BE), |
| .rates = SNDRV_PCM_RATE_CONTINUOUS | SNDRV_PCM_RATE_8000_768000, |
| .rate_min = 8000, |
| .rate_max = 768000, |
| .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) |