diff options
Diffstat (limited to 'loopback')
| -rw-r--r-- | loopback/Kconfig | 12 | ||||
| -rw-r--r-- | loopback/Makefile | 7 | ||||
| -rw-r--r-- | loopback/loopback.c | 1111 |
3 files changed, 1130 insertions, 0 deletions
diff --git a/loopback/Kconfig b/loopback/Kconfig new file mode 100644 index 0000000..6293c5c --- /dev/null +++ b/loopback/Kconfig @@ -0,0 +1,12 @@ +# +# AVIRT Loopback Audio Path +# + +config AVIRT_LOOPBACKAP + tristate "LoopbackAP" + select SND_PCM + ---help--- + Say Y here if you want to add loopback audio path. + + To compile this driver as a module, choose M here: the + module will be called avirt_loopbackap. diff --git a/loopback/Makefile b/loopback/Makefile new file mode 100644 index 0000000..0546168 --- /dev/null +++ b/loopback/Makefile @@ -0,0 +1,7 @@ +# SPDX-License-Identifier: GPL-2.0 +obj-$(CONFIG_AVIRT_AP_LOOPBACK) += snd-avirt-ap-loopback.o + +$(info $(src)) +snd-avirt-ap-loopback-objs := loopback.o +ccflags-y += -Idrivers/staging/ +ccflags-y += -I$(src)/../ diff --git a/loopback/loopback.c b/loopback/loopback.c new file mode 100644 index 0000000..b4a82e5 --- /dev/null +++ b/loopback/loopback.c @@ -0,0 +1,1111 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Loopback Audio Path for AVIRT + * + * 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> + * + * Adapt to use AVIRT, looping is now conducted on the same PCM device + * Copyright (c) 2010-2018 Fiberdyne Systems Pty Ltd + * + * loopback.c - Loopback Audio Path driver implementation for AVIRT + */ + +#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/control.h> +#include <sound/pcm.h> +#include <sound/pcm_params.h> +#include <sound/info.h> +#include <sound/initval.h> +#include <sound/avirt.h> + +MODULE_AUTHOR("Jaroslav Kysela <perex@perex.cz>"); +MODULE_DESCRIPTION("Loopback Audio Path for AVIRT"); +MODULE_LICENSE("GPL"); + +#define AP_UID "ap_loopback" + +#define AP_INFOK(fmt, args...) DINFO(AP_UID, fmt, ##args) +#define AP_PRINTK(fmt, args...) DDEBUG(AP_UID, fmt, ##args) +#define AP_ERRORK(fmt, args...) DERROR(AP_UID, fmt, ##args) + +#define NO_PITCH 100000 + +static struct snd_avirt_coreinfo *coreinfo; +static struct loopback *loopback; + +struct loopback_pcm; + +struct loopback_cable { + spinlock_t lock; + struct loopback_pcm *streams[2]; + struct snd_pcm_hardware hw; + /* flags */ + unsigned int valid; + unsigned int running; + unsigned int pause; +}; + +struct loopback_setup { + unsigned int notify : 1; + unsigned int rate_shift; + unsigned int format; + unsigned int rate; + unsigned int channels; + struct snd_ctl_elem_id active_id; + struct snd_ctl_elem_id format_id; + struct snd_ctl_elem_id rate_id; + struct snd_ctl_elem_id channels_id; +}; + +struct loopback { + struct snd_card *card; + struct mutex cable_lock; + struct loopback_cable *cables[MAX_STREAMS]; + struct snd_pcm *pcm[MAX_STREAMS]; + struct loopback_setup setup[MAX_STREAMS]; +}; + +struct loopback_pcm { + struct loopback *loopback; + struct snd_pcm_substream *substream; + struct loopback_cable *cable; + unsigned int pcm_buffer_size; + unsigned int buf_pos; /* position in buffer */ + unsigned int silent_size; + /* PCM parameters */ + unsigned int pcm_period_size; + unsigned int pcm_bps; /* bytes per second */ + unsigned int pcm_salign; /* bytes per sample * channels */ + unsigned int pcm_rate_shift; /* rate shift value */ + /* flags */ + unsigned int period_update_pending : 1; + /* timer stuff */ + unsigned int irq_pos; /* fractional IRQ position */ + unsigned int period_size_frac; + unsigned int last_drift; + unsigned long last_jiffies; + struct timer_list timer; +}; + +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) +{ + return &dpcm->loopback->setup[dpcm->substream->pcm->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 void loopback_timer_start(struct loopback_pcm *dpcm) +{ + unsigned long tick; + unsigned int rate_shift = get_rate_shift(dpcm); + + if (rate_shift != dpcm->pcm_rate_shift) { + dpcm->pcm_rate_shift = rate_shift; + dpcm->period_size_frac = frac_pos(dpcm, dpcm->pcm_period_size); + } + if (dpcm->period_size_frac <= dpcm->irq_pos) { + dpcm->irq_pos %= dpcm->period_size_frac; + dpcm->period_update_pending = 1; + } + tick = dpcm->period_size_frac - dpcm->irq_pos; + tick = (tick + dpcm->pcm_bps - 1) / dpcm->pcm_bps; + mod_timer(&dpcm->timer, jiffies + tick); +} + +/* call in cable->lock */ +static inline void loopback_timer_stop(struct loopback_pcm *dpcm) +{ + del_timer(&dpcm->timer); + dpcm->timer.expires = 0; +} + +static inline void loopback_timer_stop_sync(struct loopback_pcm *dpcm) +{ + del_timer_sync(&dpcm->timer); +} + +#define CABLE_VALID_PLAYBACK (1 << SNDRV_PCM_STREAM_PLAYBACK) +#define CABLE_VALID_CAPTURE (1 << SNDRV_PCM_STREAM_CAPTURE) +#define CABLE_VALID_BOTH (CABLE_VALID_PLAYBACK | CABLE_VALID_CAPTURE) + +static int loopback_check_format(struct loopback_cable *cable, int stream) +{ + struct snd_pcm_runtime *runtime, *cruntime; + struct loopback_setup *setup; + struct snd_card *card; + int check; + + if (cable->valid != CABLE_VALID_BOTH) { + if (stream == SNDRV_PCM_STREAM_PLAYBACK) + goto __notify; + return 0; + } + runtime = cable->streams[SNDRV_PCM_STREAM_PLAYBACK]->substream->runtime; + cruntime = cable->streams[SNDRV_PCM_STREAM_CAPTURE]->substream->runtime; + check = runtime->format != cruntime->format || + runtime->rate != cruntime->rate || + runtime->channels != cruntime->channels; + if (!check) + return 0; + if (stream == SNDRV_PCM_STREAM_CAPTURE) { + return -EIO; + } else { + snd_pcm_stop( + cable->streams[SNDRV_PCM_STREAM_CAPTURE]->substream, + SNDRV_PCM_STATE_DRAINING); + __notify: + runtime = cable->streams[SNDRV_PCM_STREAM_PLAYBACK] + ->substream->runtime; + setup = get_setup(cable->streams[SNDRV_PCM_STREAM_PLAYBACK]); + card = cable->streams[SNDRV_PCM_STREAM_PLAYBACK]->loopback->card; + if (setup->format != runtime->format) { + snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_VALUE, + &setup->format_id); + setup->format = runtime->format; + } + if (setup->rate != runtime->rate) { + snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_VALUE, + &setup->rate_id); + setup->rate = runtime->rate; + } + if (setup->channels != runtime->channels) { + snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_VALUE, + &setup->channels_id); + setup->channels = runtime->channels; + } + } + return 0; +} + +static void loopback_active_notify(struct loopback_pcm *dpcm) +{ + snd_ctl_notify(dpcm->loopback->card, SNDRV_CTL_EVENT_MASK_VALUE, + &get_setup(dpcm)->active_id); +} + +static int loopback_trigger(struct snd_pcm_substream *substream, int cmd) +{ + struct snd_pcm_runtime *runtime = substream->runtime; + struct loopback_pcm *dpcm = runtime->private_data; + struct loopback_cable *cable = dpcm->cable; + int err, stream = 1 << substream->stream; + + AP_INFOK(); + + 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; + loopback_timer_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; + loopback_timer_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; + loopback_timer_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; + loopback_timer_start(dpcm); + spin_unlock(&cable->lock); + if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) + loopback_active_notify(dpcm); + break; + default: + return -EINVAL; + } + return 0; +} + +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; +} + +static int loopback_prepare(struct snd_pcm_substream *substream) +{ + struct snd_pcm_runtime *runtime = substream->runtime; + struct loopback_pcm *dpcm = runtime->private_data; + struct loopback_cable *cable = dpcm->cable; + int bps, salign; + + loopback_timer_stop_sync(dpcm); + + salign = + (snd_pcm_format_width(runtime->format) * runtime->channels) / 8; + bps = salign * runtime->rate; + if (bps <= 0 || salign <= 0) + return -EINVAL; + + dpcm->buf_pos = 0; + dpcm->pcm_buffer_size = frames_to_bytes(runtime, runtime->buffer_size); + if (substream->stream == SNDRV_PCM_STREAM_CAPTURE) { + /* clear capture buffer */ + dpcm->silent_size = dpcm->pcm_buffer_size; + snd_pcm_format_set_silence(runtime->format, runtime->dma_area, + runtime->buffer_size * + runtime->channels); + } + + dpcm->irq_pos = 0; + dpcm->period_update_pending = 0; + dpcm->pcm_bps = bps; + dpcm->pcm_salign = salign; + dpcm->pcm_period_size = frames_to_bytes(runtime, runtime->period_size); + + mutex_lock(&dpcm->loopback->cable_lock); + if (!(cable->valid & ~(1 << substream->stream)) || + (get_setup(dpcm)->notify && + substream->stream == SNDRV_PCM_STREAM_PLAYBACK)) + params_change(substream); + cable->valid |= 1 << substream->stream; + mutex_unlock(&dpcm->loopback->cable_lock); + + return 0; +} + +static void clear_capture_buf(struct loopback_pcm *dpcm, unsigned int bytes) +{ + struct snd_pcm_runtime *runtime = dpcm->substream->runtime; + char *dst = runtime->dma_area; + unsigned int dst_off = dpcm->buf_pos; + + if (dpcm->silent_size >= dpcm->pcm_buffer_size) + return; + if (dpcm->silent_size + bytes > dpcm->pcm_buffer_size) + bytes = dpcm->pcm_buffer_size - dpcm->silent_size; + + for (;;) { + unsigned int size = bytes; + if (dst_off + size > dpcm->pcm_buffer_size) + size = dpcm->pcm_buffer_size - dst_off; + snd_pcm_format_set_silence(runtime->format, dst + dst_off, + bytes_to_frames(runtime, size) * + runtime->channels); + dpcm->silent_size += size; + bytes -= size; + if (!bytes) + break; + dst_off = 0; + } +} + +static void copy_play_buf(struct loopback_pcm *play, struct loopback_pcm *capt, + unsigned int bytes) +{ + struct snd_pcm_runtime *runtime = play->substream->runtime; + char *src = runtime->dma_area; + char *dst = capt->substream->runtime->dma_area; + unsigned int src_off = play->buf_pos; + unsigned int dst_off = capt->buf_pos; + unsigned int clear_bytes = 0; + + /* check if playback is draining, trim the capture copy size + * when our pointer is at the end of playback ring buffer */ + if (runtime->status->state == SNDRV_PCM_STATE_DRAINING && + snd_pcm_playback_hw_avail(runtime) < runtime->buffer_size) { + snd_pcm_uframes_t appl_ptr, appl_ptr1, diff; + appl_ptr = appl_ptr1 = runtime->control->appl_ptr; + appl_ptr1 -= appl_ptr1 % runtime->buffer_size; + appl_ptr1 += play->buf_pos / play->pcm_salign; + if (appl_ptr < appl_ptr1) + appl_ptr1 -= runtime->buffer_size; + diff = (appl_ptr - appl_ptr1) * play->pcm_salign; + if (diff < bytes) { + clear_bytes = bytes - diff; + bytes = diff; + } + } + + for (;;) { + unsigned int size = bytes; + if (src_off + size > play->pcm_buffer_size) + size = play->pcm_buffer_size - src_off; + if (dst_off + size > capt->pcm_buffer_size) + size = capt->pcm_buffer_size - dst_off; + memcpy(dst + dst_off, src + src_off, size); + capt->silent_size = 0; + bytes -= size; + if (!bytes) + break; + src_off = (src_off + size) % play->pcm_buffer_size; + dst_off = (dst_off + size) % capt->pcm_buffer_size; + } + + if (clear_bytes > 0) { + clear_capture_buf(capt, clear_bytes); + capt->silent_size = 0; + } +} + +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_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; + unsigned int running, count1, count2; + + running = cable->running ^ cable->pause; + if (running & (1 << SNDRV_PCM_STREAM_PLAYBACK)) { + delta_play = jiffies - dpcm_play->last_jiffies; + dpcm_play->last_jiffies += delta_play; + } + + if (running & (1 << SNDRV_PCM_STREAM_CAPTURE)) { + delta_capt = jiffies - dpcm_capt->last_jiffies; + dpcm_capt->last_jiffies += delta_capt; + } + + if (delta_play == 0 && delta_capt == 0) + 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_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_pos_update(dpcm->cable) & (1 << dpcm->substream->stream)) { + loopback_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_avirt_pcm_period_elapsed(dpcm->substream); + return; + } + } + spin_unlock_irqrestore(&dpcm->cable->lock, flags); +} + +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); + loopback_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 loopbackap_pcm_hardware = { + .info = (SNDRV_PCM_INFO_INTERLEAVED | SNDRV_PCM_INFO_MMAP | + SNDRV_PCM_INFO_MMAP_VALID | SNDRV_PCM_INFO_PAUSE | + SNDRV_PCM_INFO_RESUME), + .formats = (SNDRV_PCM_FMTBIT_S16_LE | SNDRV_PCM_FMTBIT_S16_BE | + SNDRV_PCM_FMTBIT_S32_LE | SNDRV_PCM_FMTBIT_S32_BE | + SNDRV_PCM_FMTBIT_FLOAT_LE | SNDRV_PCM_FMTBIT_FLOAT_BE), + .rates = SNDRV_PCM_RATE_CONTINUOUS | SNDRV_PCM_RATE_8000_192000, + .rate_min = 8000, + .rate_max = 192000, + .channels_min = 1, + .channels_max = 32, + .buffer_bytes_max = 2 * 1024 * 1024, + .period_bytes_min = 64, + /* note check overflow in frac_pos() using pcm_rate_shift before + changing period_bytes_max value */ + .period_bytes_max = 1024 * 1024, + .periods_min = 1, + .periods_max = 1024, + .fifo_size = 0, +}; + +static void loopback_runtime_free(struct snd_pcm_runtime *runtime) +{ + struct loopback_pcm *dpcm = runtime->private_data; + kfree(dpcm); +} + +static int loopback_hw_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 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 void free_cable(struct snd_pcm_substream *substream) +{ + struct loopback_cable *cable; + + cable = loopback->cables[substream->pcm->device]; + 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 { + /* free the cable */ + loopback->cables[substream->pcm->device] = NULL; + kfree(cable); + } +} + +static int loopback_open(struct snd_pcm_substream *substream) +{ + struct snd_pcm_runtime *runtime = substream->runtime; + struct loopback_pcm *dpcm; + struct loopback_cable *cable = NULL; + int err = 0; + + mutex_lock(&loopback->cable_lock); + dpcm = kzalloc(sizeof(*dpcm), GFP_KERNEL); + if (!dpcm) { + err = -ENOMEM; + goto unlock; + } + dpcm->loopback = loopback; + dpcm->substream = substream; + timer_setup(&dpcm->timer, loopback_timer_function, 0); + + cable = loopback->cables[substream->pcm->device]; + if (!cable) { + cable = kzalloc(sizeof(*cable), GFP_KERNEL); + if (!cable) { + err = -ENOMEM; + goto unlock; + } + spin_lock_init(&cable->lock); + cable->hw = loopbackap_pcm_hardware; + loopback->cables[substream->pcm->device] = cable; + } + dpcm->cable = cable; + + 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; + + runtime->private_data = dpcm; + runtime->private_free = loopback_runtime_free; + if (get_notify(dpcm)) + runtime->hw = loopbackap_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_pcm *dpcm = substream->runtime->private_data; + + loopback_timer_stop_sync(dpcm); + mutex_lock(&loopback->cable_lock); + free_cable(substream); + mutex_unlock(&loopback->cable_lock); + return 0; +} + +static const struct snd_pcm_ops loopbackap_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_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.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.device].rate_shift) { + loopback->setup[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.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.device].notify) { + loopback->setup[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.device]; + 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 = SNDRV_PCM_FORMAT_LAST; + uinfo->value.integer.step = 1; + return 0; +} + +static int loopback_format_get(struct snd_kcontrol *kcontrol, + struct snd_ctl_elem_value *ucontrol) +{ + struct loopback *loopback = snd_kcontrol_chip(kcontrol); + + ucontrol->value.integer.value[0] = + loopback->setup[kcontrol->id.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.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.device].channels; + mutex_unlock(&loopback->cable_lock); + return 0; +} + +static 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 } +}; + +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 dev, dev_count, idx, err; + + strcpy(card->mixername, "Loopback Mixer"); + dev_count = snd_avirt_stream_count(SNDRV_PCM_STREAM_PLAYBACK); + for (dev = 0; dev < dev_count; dev++) { + pcm = loopback->pcm[dev]; + setup = &loopback->setup[dev]; + setup->notify = notify; + setup->rate_shift = NO_PITCH; + setup->format = SNDRV_PCM_FORMAT_S16_LE; + setup->rate = 48000; + setup->channels = 2; + for (idx = 0; idx < ARRAY_SIZE(loopback_controls); idx++) { + kctl = snd_ctl_new1(&loopback_controls[idx], loopback); + if (!kctl) + return -ENOMEM; + kctl->id.device = dev; + kctl->id.subdevice = 0; + switch (idx) { + case ACTIVE_IDX: + setup->active_id = kctl->id; + break; + case FORMAT_IDX: + setup->format_id = kctl->id; + break; + case RATE_IDX: + setup->rate_id = kctl->id; + break; + case CHANNELS_IDX: + setup->channels_id = kctl->id; + break; + default: + break; + } + err = snd_ctl_add(card, kctl); + if (err < 0) + return err; + } + } + return 0; +} + +static void print_dpcm_info(struct snd_info_buffer *buffer, + struct loopback_pcm *dpcm, const char *id) +{ + snd_iprintf(buffer, " %s\n", id); + if (dpcm == NULL) { + snd_iprintf(buffer, " inactive\n"); + return; + } + snd_iprintf(buffer, " buffer_size:\t%u\n", dpcm->pcm_buffer_size); + snd_iprintf(buffer, " buffer_pos:\t\t%u\n", dpcm->buf_pos); + snd_iprintf(buffer, " silent_size:\t%u\n", dpcm->silent_size); + snd_iprintf(buffer, " period_size:\t%u\n", dpcm->pcm_period_size); + snd_iprintf(buffer, " bytes_per_sec:\t%u\n", dpcm->pcm_bps); + snd_iprintf(buffer, " sample_align:\t%u\n", dpcm->pcm_salign); + snd_iprintf(buffer, " rate_shift:\t\t%u\n", dpcm->pcm_rate_shift); + snd_iprintf(buffer, " update_pending:\t%u\n", + dpcm->period_update_pending); + snd_iprintf(buffer, " irq_pos:\t\t%u\n", dpcm->irq_pos); + snd_iprintf(buffer, " period_frac:\t%u\n", dpcm->period_size_frac); + snd_iprintf(buffer, " last_jiffies:\t%lu (%lu)\n", + dpcm->last_jiffies, jiffies); + snd_iprintf(buffer, " timer_expires:\t%lu\n", dpcm->timer.expires); +} + +static void print_substream_info(struct snd_info_buffer *buffer, + struct loopback *loopback, int device) +{ + struct loopback_cable *cable = loopback->cables[device]; + + snd_iprintf(buffer, "Cable device %i:\n", device); + 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 device; + + mutex_lock(&loopback->cable_lock); + for (device = 0; device < MAX_STREAMS; device++) + print_substream_info(buffer, loopback, device); + mutex_unlock(&loopback->cable_lock); +} + +static int loopback_proc_new(struct loopback *loopback, int cidx) +{ + char name[32]; + struct snd_info_entry *entry; + int err; + + snprintf(name, sizeof(name), "cable#%d", cidx); + err = snd_card_proc_new(loopback->card, name, &entry); + if (err < 0) + return err; + + snd_info_set_text_ops(entry, loopback, print_cable_info); + return 0; +} + +static int loopbackap_configure(struct snd_card *card, + struct config_group *snd_avirt_stream_group, + unsigned int stream_count) +{ + int err; + struct list_head *entry; + + loopback = kzalloc(sizeof(struct loopback), GFP_KERNEL); + if (!loopback) + return -ENOMEM; + loopback->card = card; + mutex_init(&loopback->cable_lock); + + list_for_each (entry, &snd_avirt_stream_group->cg_children) { + struct config_item *item = + container_of(entry, struct config_item, ci_entry); + struct snd_avirt_stream *stream = + snd_avirt_stream_from_config_item(item); + loopback->pcm[stream->device] = stream->pcm; + + AP_INFOK("stream name:%s device:%d channels:%d", stream->name, + stream->device, stream->channels); + } + + err = loopback_mixer_new(loopback, 1); + if (err < 0) + return err; + + loopback_proc_new(loopback, 0); + loopback_proc_new(loopback, 1); + + return 0; +} + +/******************************************************************************* + * Loopback Audio Path AVIRT registration + ******************************************************************************/ +static struct snd_avirt_audiopath loopbackap_module = { + .uid = AP_UID, + .name = "Loopback Audio Path", + .version = { 0, 0, 1 }, + .hw = &loopbackap_pcm_hardware, + .pcm_ops = &loopbackap_pcm_ops, + .configure = loopbackap_configure, +}; + +static int __init alsa_card_loopback_init(void) +{ + int err = 0; + + err = snd_avirt_audiopath_register(&loopbackap_module, &coreinfo); + if ((err < 0) || (!coreinfo)) { + AP_ERRORK("coreinfo is NULL!"); + return err; + } + + return 0; +} + +static void __exit alsa_card_loopback_exit(void) +{ + snd_avirt_audiopath_deregister(&loopbackap_module); +} + +module_init(alsa_card_loopback_init); +module_exit(alsa_card_loopback_exit) |