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-rw-r--r--sound/drivers/aloop.c1837
1 files changed, 1837 insertions, 0 deletions
diff --git a/sound/drivers/aloop.c b/sound/drivers/aloop.c
new file mode 100644
index 000000000..a38e602b4
--- /dev/null
+++ b/sound/drivers/aloop.c
@@ -0,0 +1,1837 @@
+// 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;
+ unsigned int channels;
+ struct snd_ctl_elem_id active_id;
+ struct snd_ctl_elem_id format_id;
+ struct snd_ctl_elem_id rate_id;
+ struct snd_ctl_elem_id channels_id;
+};
+
+struct loopback {
+ struct snd_card *card;
+ struct mutex cable_lock;
+ struct loopback_cable *cables[MAX_PCM_SUBSTREAMS][2];
+ struct snd_pcm *pcm[2];
+ struct loopback_setup setup[MAX_PCM_SUBSTREAMS][2];
+ 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;
+};
+
+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 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 = 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);
+ 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->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_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),
+ .formats = (SNDRV_PCM_FMTBIT_S16_LE | SNDRV_PCM_FMTBIT_S16_BE |
+ SNDRV_PCM_FMTBIT_S24_LE | SNDRV_PCM_FMTBIT_S24_BE |
+ SNDRV_PCM_FMTBIT_S24_3LE | SNDRV_PCM_FMTBIT_S24_3BE |
+ SNDRV_PCM_FMTBIT_S32_LE | SNDRV_PCM_FMTBIT_S32_BE |
+ SNDRV_PCM_FMTBIT_FLOAT_LE | SNDRV_PCM_FMTBIT_FLOAT_BE),
+ .rates = SNDRV_PCM_RATE_CONTINUOUS | SNDRV_PCM_RATE_8000_192000,
+ .rate_min = 8000,
+ .rate_max = 192000,
+ .channels_min = 1,
+ .channels_max = 32,
+ .buffer_bytes_max = 2 * 1024 * 1024,
+ .period_bytes_min = 64,
+ /* note check overflow in frac_pos() using pcm_rate_shift before
+ changing period_bytes_max value */
+ .period_bytes_max = 1024 * 1024,
+ .periods_min = 1,
+ .periods_max = 1024,
+ .fifo_size = 0,
+};
+
+static void loopback_runtime_free(struct snd_pcm_runtime *runtime)
+{
+ struct loopback_pcm *dpcm = runtime->private_data;
+ kfree(dpcm);
+}
+
+static int loopback_hw_free(struct snd_pcm_substream *substream)
+{
+ struct snd_pcm_runtime *runtime = substream->runtime;
+ struct loopback_pcm *dpcm = runtime->private_data;
+ struct loopback_cable *cable = dpcm->cable;
+
+ mutex_lock(&dpcm->loopback->cable_lock);
+ cable->valid &= ~(1 << substream->stream);
+ mutex_unlock(&dpcm->loopback->cable_lock);
+ return 0;
+}
+
+static unsigned int get_cable_index(struct snd_pcm_substream *substream)
+{
+ if (!substream->pcm->device)
+ return substream->stream;
+ else
+ return !substream->stream;
+}
+
+static int rule_format(struct snd_pcm_hw_params *params,
+ struct snd_pcm_hw_rule *rule)
+{
+ struct loopback_pcm *dpcm = rule->private;
+ struct loopback_cable *cable = dpcm->cable;
+ struct snd_mask m;
+
+ snd_mask_none(&m);
+ mutex_lock(&dpcm->loopback->cable_lock);
+ m.bits[0] = (u_int32_t)cable->hw.formats;
+ m.bits[1] = (u_int32_t)(cable->hw.formats >> 32);
+ mutex_unlock(&dpcm->loopback->cable_lock);
+ return snd_mask_refine(hw_param_mask(params, rule->var), &m);
+}
+
+static int rule_rate(struct snd_pcm_hw_params *params,
+ struct snd_pcm_hw_rule *rule)
+{
+ struct loopback_pcm *dpcm = rule->private;
+ struct loopback_cable *cable = dpcm->cable;
+ struct snd_interval t;
+
+ mutex_lock(&dpcm->loopback->cable_lock);
+ t.min = cable->hw.rate_min;
+ t.max = cable->hw.rate_max;
+ mutex_unlock(&dpcm->loopback->cable_lock);
+ t.openmin = t.openmax = 0;
+ t.integer = 0;
+ return snd_interval_refine(hw_param_interval(params, rule->var), &t);
+}
+
+static int rule_channels(struct snd_pcm_hw_params *params,
+ struct snd_pcm_hw_rule *rule)
+{
+ struct loopback_pcm *dpcm = rule->private;
+ struct loopback_cable *cable = dpcm->cable;
+ struct snd_interval t;
+
+ mutex_lock(&dpcm->loopback->cable_lock);
+ t.min = cable->hw.channels_min;
+ t.max = cable->hw.channels_max;
+ mutex_unlock(&dpcm->loopback->cable_lock);
+ t.openmin = t.openmax = 0;
+ t.integer = 0;
+ return snd_interval_refine(hw_param_interval(params, rule->var), &t);
+}
+
+static int rule_period_bytes(struct snd_pcm_hw_params *params,
+ struct snd_pcm_hw_rule *rule)
+{
+ struct loopback_pcm *dpcm = rule->private;
+ struct loopback_cable *cable = dpcm->cable;
+ struct snd_interval t;
+
+ mutex_lock(&dpcm->loopback->cable_lock);
+ t.min = cable->hw.period_bytes_min;
+ t.max = cable->hw.period_bytes_max;
+ mutex_unlock(&dpcm->loopback->cable_lock);
+ t.openmin = 0;
+ t.openmax = 0;
+ t.integer = 0;
+ return snd_interval_refine(hw_param_interval(params, rule->var), &t);
+}
+
+static void free_cable(struct snd_pcm_substream *substream)
+{
+ struct loopback *loopback = substream->private_data;
+ int dev = get_cable_index(substream);
+ struct loopback_cable *cable;
+
+ cable = loopback->cables[substream->number][dev];
+ if (!cable)
+ return;
+ if (cable->streams[!substream->stream]) {
+ /* other stream is still alive */
+ spin_lock_irq(&cable->lock);
+ cable->streams[substream->stream] = NULL;
+ spin_unlock_irq(&cable->lock);
+ } else {
+ struct loopback_pcm *dpcm = substream->runtime->private_data;
+
+ if (cable->ops && cable->ops->close_cable && dpcm)
+ cable->ops->close_cable(dpcm);
+ /* free the cable */
+ loopback->cables[substream->number][dev] = NULL;
+ kfree(cable);
+ }
+}
+
+static int loopback_jiffies_timer_open(struct loopback_pcm *dpcm)
+{
+ timer_setup(&dpcm->timer, loopback_jiffies_timer_function, 0);
+
+ return 0;
+}
+
+static const struct loopback_ops loopback_jiffies_timer_ops = {
+ .open = loopback_jiffies_timer_open,
+ .start = loopback_jiffies_timer_start,
+ .stop = loopback_jiffies_timer_stop,
+ .stop_sync = loopback_jiffies_timer_stop_sync,
+ .close_substream = loopback_jiffies_timer_stop_sync,
+ .pos_update = loopback_jiffies_timer_pos_update,
+ .dpcm_info = loopback_jiffies_timer_dpcm_info,
+};
+
+static int loopback_parse_timer_id(const char *str,
+ struct snd_timer_id *tid)
+{
+ /* [<pref>:](<card name>|<card idx>)[{.,}<dev idx>[{.,}<subdev idx>]] */
+ const char * const sep_dev = ".,";
+ const char * const sep_pref = ":";
+ const char *name = str;
+ char *sep, save = '\0';
+ int card_idx = 0, dev = 0, subdev = 0;
+ int err;
+
+ sep = strpbrk(str, sep_pref);
+ if (sep)
+ name = sep + 1;
+ sep = strpbrk(name, sep_dev);
+ if (sep) {
+ save = *sep;
+ *sep = '\0';
+ }
+ err = kstrtoint(name, 0, &card_idx);
+ if (err == -EINVAL) {
+ /* Must be the name, not number */
+ for (card_idx = 0; card_idx < snd_ecards_limit; card_idx++) {
+ struct snd_card *card = snd_card_ref(card_idx);
+
+ if (card) {
+ if (!strcmp(card->id, name))
+ err = 0;
+ snd_card_unref(card);
+ }
+ if (!err)
+ break;
+ }
+ }
+ if (sep) {
+ *sep = save;
+ if (!err) {
+ char *sep2, save2 = '\0';
+
+ sep2 = strpbrk(sep + 1, sep_dev);
+ if (sep2) {
+ save2 = *sep2;
+ *sep2 = '\0';
+ }
+ err = kstrtoint(sep + 1, 0, &dev);
+ if (sep2) {
+ *sep2 = save2;
+ if (!err)
+ err = kstrtoint(sep2 + 1, 0, &subdev);
+ }
+ }
+ }
+ if (!err && tid) {
+ tid->card = card_idx;
+ tid->device = dev;
+ tid->subdevice = subdev;
+ }
+ return err;
+}
+
+/* call in loopback->cable_lock */
+static int loopback_snd_timer_open(struct loopback_pcm *dpcm)
+{
+ int err = 0;
+ struct snd_timer_id tid = {
+ .dev_class = SNDRV_TIMER_CLASS_PCM,
+ .dev_sclass = SNDRV_TIMER_SCLASS_APPLICATION,
+ };
+ struct snd_timer_instance *timeri;
+ struct loopback_cable *cable = dpcm->cable;
+
+ /* check if timer was already opened. It is only opened once
+ * per playback and capture subdevice (aka cable).
+ */
+ if (cable->snd_timer.instance)
+ goto exit;
+
+ err = loopback_parse_timer_id(dpcm->loopback->timer_source, &tid);
+ if (err < 0) {
+ pcm_err(dpcm->substream->pcm,
+ "Parsing timer source \'%s\' failed with %d",
+ dpcm->loopback->timer_source, err);
+ goto exit;
+ }
+
+ cable->snd_timer.stream = dpcm->substream->stream;
+ cable->snd_timer.id = tid;
+
+ timeri = snd_timer_instance_new(dpcm->loopback->card->id);
+ if (!timeri) {
+ err = -ENOMEM;
+ goto exit;
+ }
+ /* The callback has to be called from another work. If
+ * SNDRV_TIMER_IFLG_FAST is specified it will be called from the
+ * snd_pcm_period_elapsed() call of the selected sound card.
+ * snd_pcm_period_elapsed() helds snd_pcm_stream_lock_irqsave().
+ * Due to our callback loopback_snd_timer_function() also calls
+ * snd_pcm_period_elapsed() which calls snd_pcm_stream_lock_irqsave().
+ * This would end up in a dead lock.
+ */
+ timeri->flags |= SNDRV_TIMER_IFLG_AUTO;
+ timeri->callback = loopback_snd_timer_function;
+ timeri->callback_data = (void *)cable;
+ timeri->ccallback = loopback_snd_timer_event;
+
+ /* initialise a work used for draining */
+ INIT_WORK(&cable->snd_timer.event_work, loopback_snd_timer_work);
+
+ /* The mutex loopback->cable_lock is kept locked.
+ * Therefore snd_timer_open() cannot be called a second time
+ * by the other device of the same cable.
+ * Therefore the following issue cannot happen:
+ * [proc1] Call loopback_timer_open() ->
+ * Unlock cable->lock for snd_timer_close/open() call
+ * [proc2] Call loopback_timer_open() -> snd_timer_open(),
+ * snd_timer_start()
+ * [proc1] Call snd_timer_open() and overwrite running timer
+ * instance
+ */
+ err = snd_timer_open(timeri, &cable->snd_timer.id, current->pid);
+ if (err < 0) {
+ pcm_err(dpcm->substream->pcm,
+ "snd_timer_open (%d,%d,%d) failed with %d",
+ cable->snd_timer.id.card,
+ cable->snd_timer.id.device,
+ cable->snd_timer.id.subdevice,
+ err);
+ snd_timer_instance_free(timeri);
+ goto exit;
+ }
+
+ cable->snd_timer.instance = timeri;
+
+exit:
+ return err;
+}
+
+/* stop_sync() is not required for sound timer because it does not need to be
+ * restarted in loopback_prepare() on Xrun recovery
+ */
+static const struct loopback_ops loopback_snd_timer_ops = {
+ .open = loopback_snd_timer_open,
+ .start = loopback_snd_timer_start,
+ .stop = loopback_snd_timer_stop,
+ .close_cable = loopback_snd_timer_close_cable,
+ .dpcm_info = loopback_snd_timer_dpcm_info,
+};
+
+static int loopback_open(struct snd_pcm_substream *substream)
+{
+ struct snd_pcm_runtime *runtime = substream->runtime;
+ struct loopback *loopback = substream->private_data;
+ struct loopback_pcm *dpcm;
+ struct loopback_cable *cable = NULL;
+ int err = 0;
+ int dev = get_cable_index(substream);
+
+ mutex_lock(&loopback->cable_lock);
+ dpcm = kzalloc(sizeof(*dpcm), GFP_KERNEL);
+ if (!dpcm) {
+ err = -ENOMEM;
+ goto unlock;
+ }
+ dpcm->loopback = loopback;
+ dpcm->substream = substream;
+
+ cable = loopback->cables[substream->number][dev];
+ if (!cable) {
+ cable = kzalloc(sizeof(*cable), GFP_KERNEL);
+ if (!cable) {
+ err = -ENOMEM;
+ goto unlock;
+ }
+ spin_lock_init(&cable->lock);
+ cable->hw = loopback_pcm_hardware;
+ if (loopback->timer_source)
+ cable->ops = &loopback_snd_timer_ops;
+ else
+ cable->ops = &loopback_jiffies_timer_ops;
+ loopback->cables[substream->number][dev] = cable;
+ }
+ dpcm->cable = cable;
+ runtime->private_data = dpcm;
+
+ if (cable->ops->open) {
+ err = cable->ops->open(dpcm);
+ if (err < 0)
+ goto unlock;
+ }
+
+ snd_pcm_hw_constraint_integer(runtime, SNDRV_PCM_HW_PARAM_PERIODS);
+
+ /* use dynamic rules based on actual runtime->hw values */
+ /* note that the default rules created in the PCM midlevel code */
+ /* are cached -> they do not reflect the actual state */
+ err = snd_pcm_hw_rule_add(runtime, 0,
+ SNDRV_PCM_HW_PARAM_FORMAT,
+ rule_format, dpcm,
+ SNDRV_PCM_HW_PARAM_FORMAT, -1);
+ if (err < 0)
+ goto unlock;
+ err = snd_pcm_hw_rule_add(runtime, 0,
+ SNDRV_PCM_HW_PARAM_RATE,
+ rule_rate, dpcm,
+ SNDRV_PCM_HW_PARAM_RATE, -1);
+ if (err < 0)
+ goto unlock;
+ err = snd_pcm_hw_rule_add(runtime, 0,
+ SNDRV_PCM_HW_PARAM_CHANNELS,
+ rule_channels, dpcm,
+ SNDRV_PCM_HW_PARAM_CHANNELS, -1);
+ if (err < 0)
+ goto unlock;
+
+ /* In case of sound timer the period time of both devices of the same
+ * loop has to be the same.
+ * This rule only takes effect if a sound timer was chosen
+ */
+ if (cable->snd_timer.instance) {
+ err = snd_pcm_hw_rule_add(runtime, 0,
+ SNDRV_PCM_HW_PARAM_PERIOD_BYTES,
+ rule_period_bytes, dpcm,
+ SNDRV_PCM_HW_PARAM_PERIOD_BYTES, -1);
+ if (err < 0)
+ goto unlock;
+ }
+
+ /* loopback_runtime_free() has not to be called if kfree(dpcm) was
+ * already called here. Otherwise it will end up with a double free.
+ */
+ runtime->private_free = loopback_runtime_free;
+ if (get_notify(dpcm))
+ runtime->hw = loopback_pcm_hardware;
+ else
+ runtime->hw = cable->hw;
+
+ spin_lock_irq(&cable->lock);
+ cable->streams[substream->stream] = dpcm;
+ spin_unlock_irq(&cable->lock);
+
+ unlock:
+ if (err < 0) {
+ free_cable(substream);
+ kfree(dpcm);
+ }
+ mutex_unlock(&loopback->cable_lock);
+ return err;
+}
+
+static int loopback_close(struct snd_pcm_substream *substream)
+{
+ struct loopback *loopback = substream->private_data;
+ struct loopback_pcm *dpcm = substream->runtime->private_data;
+ int err = 0;
+
+ if (dpcm->cable->ops->close_substream)
+ err = dpcm->cable->ops->close_substream(dpcm);
+ mutex_lock(&loopback->cable_lock);
+ free_cable(substream);
+ mutex_unlock(&loopback->cable_lock);
+ return err;
+}
+
+static const struct snd_pcm_ops loopback_pcm_ops = {
+ .open = loopback_open,
+ .close = loopback_close,
+ .hw_free = loopback_hw_free,
+ .prepare = loopback_prepare,
+ .trigger = loopback_trigger,
+ .pointer = loopback_pointer,
+};
+
+static int loopback_pcm_new(struct loopback *loopback,
+ int device, int substreams)
+{
+ struct snd_pcm *pcm;
+ int err;
+
+ err = snd_pcm_new(loopback->card, "Loopback PCM", device,
+ substreams, substreams, &pcm);
+ if (err < 0)
+ return err;
+ snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_PLAYBACK, &loopback_pcm_ops);
+ snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_CAPTURE, &loopback_pcm_ops);
+ snd_pcm_set_managed_buffer_all(pcm, SNDRV_DMA_TYPE_VMALLOC, NULL, 0, 0);
+
+ pcm->private_data = loopback;
+ pcm->info_flags = 0;
+ strcpy(pcm->name, "Loopback PCM");
+
+ loopback->pcm[device] = pcm;
+ return 0;
+}
+
+static int loopback_rate_shift_info(struct snd_kcontrol *kcontrol,
+ struct snd_ctl_elem_info *uinfo)
+{
+ uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
+ uinfo->count = 1;
+ uinfo->value.integer.min = 80000;
+ uinfo->value.integer.max = 120000;
+ uinfo->value.integer.step = 1;
+ return 0;
+}
+
+static int loopback_rate_shift_get(struct snd_kcontrol *kcontrol,
+ struct snd_ctl_elem_value *ucontrol)
+{
+ struct loopback *loopback = snd_kcontrol_chip(kcontrol);
+
+ mutex_lock(&loopback->cable_lock);
+ ucontrol->value.integer.value[0] =
+ loopback->setup[kcontrol->id.subdevice]
+ [kcontrol->id.device].rate_shift;
+ mutex_unlock(&loopback->cable_lock);
+ return 0;
+}
+
+static int loopback_rate_shift_put(struct snd_kcontrol *kcontrol,
+ struct snd_ctl_elem_value *ucontrol)
+{
+ struct loopback *loopback = snd_kcontrol_chip(kcontrol);
+ unsigned int val;
+ int change = 0;
+
+ val = ucontrol->value.integer.value[0];
+ if (val < 80000)
+ val = 80000;
+ if (val > 120000)
+ val = 120000;
+ mutex_lock(&loopback->cable_lock);
+ if (val != loopback->setup[kcontrol->id.subdevice]
+ [kcontrol->id.device].rate_shift) {
+ loopback->setup[kcontrol->id.subdevice]
+ [kcontrol->id.device].rate_shift = val;
+ change = 1;
+ }
+ mutex_unlock(&loopback->cable_lock);
+ return change;
+}
+
+static int loopback_notify_get(struct snd_kcontrol *kcontrol,
+ struct snd_ctl_elem_value *ucontrol)
+{
+ struct loopback *loopback = snd_kcontrol_chip(kcontrol);
+
+ mutex_lock(&loopback->cable_lock);
+ ucontrol->value.integer.value[0] =
+ loopback->setup[kcontrol->id.subdevice]
+ [kcontrol->id.device].notify;
+ mutex_unlock(&loopback->cable_lock);
+ return 0;
+}
+
+static int loopback_notify_put(struct snd_kcontrol *kcontrol,
+ struct snd_ctl_elem_value *ucontrol)
+{
+ struct loopback *loopback = snd_kcontrol_chip(kcontrol);
+ unsigned int val;
+ int change = 0;
+
+ val = ucontrol->value.integer.value[0] ? 1 : 0;
+ mutex_lock(&loopback->cable_lock);
+ if (val != loopback->setup[kcontrol->id.subdevice]
+ [kcontrol->id.device].notify) {
+ loopback->setup[kcontrol->id.subdevice]
+ [kcontrol->id.device].notify = val;
+ change = 1;
+ }
+ mutex_unlock(&loopback->cable_lock);
+ return change;
+}
+
+static int loopback_active_get(struct snd_kcontrol *kcontrol,
+ struct snd_ctl_elem_value *ucontrol)
+{
+ struct loopback *loopback = snd_kcontrol_chip(kcontrol);
+ struct loopback_cable *cable;
+
+ unsigned int val = 0;
+
+ mutex_lock(&loopback->cable_lock);
+ cable = loopback->cables[kcontrol->id.subdevice][kcontrol->id.device ^ 1];
+ if (cable != NULL) {
+ unsigned int running = cable->running ^ cable->pause;
+
+ val = (running & (1 << SNDRV_PCM_STREAM_PLAYBACK)) ? 1 : 0;
+ }
+ mutex_unlock(&loopback->cable_lock);
+ ucontrol->value.integer.value[0] = val;
+ return 0;
+}
+
+static int loopback_format_info(struct snd_kcontrol *kcontrol,
+ struct snd_ctl_elem_info *uinfo)
+{
+ uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
+ uinfo->count = 1;
+ uinfo->value.integer.min = 0;
+ uinfo->value.integer.max = (__force int)SNDRV_PCM_FORMAT_LAST;
+ uinfo->value.integer.step = 1;
+ return 0;
+}
+
+static int loopback_format_get(struct snd_kcontrol *kcontrol,
+ struct snd_ctl_elem_value *ucontrol)
+{
+ struct loopback *loopback = snd_kcontrol_chip(kcontrol);
+
+ ucontrol->value.integer.value[0] =
+ (__force int)loopback->setup[kcontrol->id.subdevice]
+ [kcontrol->id.device].format;
+ return 0;
+}
+
+static int loopback_rate_info(struct snd_kcontrol *kcontrol,
+ struct snd_ctl_elem_info *uinfo)
+{
+ uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
+ uinfo->count = 1;
+ uinfo->value.integer.min = 0;
+ uinfo->value.integer.max = 192000;
+ uinfo->value.integer.step = 1;
+ return 0;
+}
+
+static int loopback_rate_get(struct snd_kcontrol *kcontrol,
+ struct snd_ctl_elem_value *ucontrol)
+{
+ struct loopback *loopback = snd_kcontrol_chip(kcontrol);
+
+ mutex_lock(&loopback->cable_lock);
+ ucontrol->value.integer.value[0] =
+ loopback->setup[kcontrol->id.subdevice]
+ [kcontrol->id.device].rate;
+ mutex_unlock(&loopback->cable_lock);
+ return 0;
+}
+
+static int loopback_channels_info(struct snd_kcontrol *kcontrol,
+ struct snd_ctl_elem_info *uinfo)
+{
+ uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
+ uinfo->count = 1;
+ uinfo->value.integer.min = 1;
+ uinfo->value.integer.max = 1024;
+ uinfo->value.integer.step = 1;
+ return 0;
+}
+
+static int loopback_channels_get(struct snd_kcontrol *kcontrol,
+ struct snd_ctl_elem_value *ucontrol)
+{
+ struct loopback *loopback = snd_kcontrol_chip(kcontrol);
+
+ mutex_lock(&loopback->cable_lock);
+ ucontrol->value.integer.value[0] =
+ loopback->setup[kcontrol->id.subdevice]
+ [kcontrol->id.device].channels;
+ mutex_unlock(&loopback->cable_lock);
+ return 0;
+}
+
+static 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
+}
+};
+
+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->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;
+ 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;
+}
+
+#ifdef CONFIG_PM_SLEEP
+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 SIMPLE_DEV_PM_OPS(loopback_pm, loopback_suspend, loopback_resume);
+#define LOOPBACK_PM_OPS &loopback_pm
+#else
+#define LOOPBACK_PM_OPS NULL
+#endif
+
+#define SND_LOOPBACK_DRIVER "snd_aloop"
+
+static struct platform_driver loopback_driver = {
+ .probe = loopback_probe,
+ .driver = {
+ .name = SND_LOOPBACK_DRIVER,
+ .pm = LOOPBACK_PM_OPS,
+ },
+};
+
+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)