1 // SPDX-License-Identifier: GPL-2.0-or-later
6 * Copyright (c) by Jaroslav Kysela <perex@perex.cz>
8 * More accurate positioning and full-duplex support:
9 * Copyright (c) Ahmet İnan <ainan at mathematik.uni-freiburg.de>
11 * Major (almost complete) rewrite:
12 * Copyright (c) by Takashi Iwai <tiwai@suse.de>
14 * A next major update in 2010 (separate timers for playback and capture):
15 * Copyright (c) Jaroslav Kysela <perex@perex.cz>
18 #include <linux/init.h>
19 #include <linux/jiffies.h>
20 #include <linux/slab.h>
21 #include <linux/time.h>
22 #include <linux/wait.h>
23 #include <linux/module.h>
24 #include <linux/platform_device.h>
25 #include <sound/core.h>
26 #include <sound/control.h>
27 #include <sound/pcm.h>
28 #include <sound/pcm_params.h>
29 #include <sound/info.h>
30 #include <sound/initval.h>
31 #include <sound/timer.h>
33 MODULE_AUTHOR("Jaroslav Kysela <perex@perex.cz>");
34 MODULE_DESCRIPTION("A loopback soundcard");
35 MODULE_LICENSE("GPL");
37 #define MAX_PCM_SUBSTREAMS 8
39 static int index
[SNDRV_CARDS
] = SNDRV_DEFAULT_IDX
; /* Index 0-MAX */
40 static char *id
[SNDRV_CARDS
] = SNDRV_DEFAULT_STR
; /* ID for this card */
41 static bool enable
[SNDRV_CARDS
] = {1, [1 ... (SNDRV_CARDS
- 1)] = 0};
42 static int pcm_substreams
[SNDRV_CARDS
] = {[0 ... (SNDRV_CARDS
- 1)] = 8};
43 static int pcm_notify
[SNDRV_CARDS
];
44 static char *timer_source
[SNDRV_CARDS
];
46 module_param_array(index
, int, NULL
, 0444);
47 MODULE_PARM_DESC(index
, "Index value for loopback soundcard.");
48 module_param_array(id
, charp
, NULL
, 0444);
49 MODULE_PARM_DESC(id
, "ID string for loopback soundcard.");
50 module_param_array(enable
, bool, NULL
, 0444);
51 MODULE_PARM_DESC(enable
, "Enable this loopback soundcard.");
52 module_param_array(pcm_substreams
, int, NULL
, 0444);
53 MODULE_PARM_DESC(pcm_substreams
, "PCM substreams # (1-8) for loopback driver.");
54 module_param_array(pcm_notify
, int, NULL
, 0444);
55 MODULE_PARM_DESC(pcm_notify
, "Break capture when PCM format/rate/channels changes.");
56 module_param_array(timer_source
, charp
, NULL
, 0444);
57 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].");
59 #define NO_PITCH 100000
61 #define CABLE_VALID_PLAYBACK BIT(SNDRV_PCM_STREAM_PLAYBACK)
62 #define CABLE_VALID_CAPTURE BIT(SNDRV_PCM_STREAM_CAPTURE)
63 #define CABLE_VALID_BOTH (CABLE_VALID_PLAYBACK | CABLE_VALID_CAPTURE)
65 struct loopback_cable
;
70 * call in loopback->cable_lock
72 int (*open
)(struct loopback_pcm
*dpcm
);
76 int (*start
)(struct loopback_pcm
*dpcm
);
80 int (*stop
)(struct loopback_pcm
*dpcm
);
82 int (*stop_sync
)(struct loopback_pcm
*dpcm
);
84 int (*close_substream
)(struct loopback_pcm
*dpcm
);
86 * call in loopback->cable_lock
88 int (*close_cable
)(struct loopback_pcm
*dpcm
);
92 unsigned int (*pos_update
)(struct loopback_cable
*cable
);
94 void (*dpcm_info
)(struct loopback_pcm
*dpcm
,
95 struct snd_info_buffer
*buffer
);
98 struct loopback_cable
{
100 struct loopback_pcm
*streams
[2];
101 struct snd_pcm_hardware hw
;
104 unsigned int running
;
107 const struct loopback_ops
*ops
;
108 /* If sound timer is used */
111 struct snd_timer_id id
;
112 struct work_struct event_work
;
113 struct snd_timer_instance
*instance
;
117 struct loopback_setup
{
118 unsigned int notify
: 1;
119 unsigned int rate_shift
;
120 snd_pcm_format_t format
;
122 unsigned int channels
;
123 struct snd_ctl_elem_id active_id
;
124 struct snd_ctl_elem_id format_id
;
125 struct snd_ctl_elem_id rate_id
;
126 struct snd_ctl_elem_id channels_id
;
130 struct snd_card
*card
;
131 struct mutex cable_lock
;
132 struct loopback_cable
*cables
[MAX_PCM_SUBSTREAMS
][2];
133 struct snd_pcm
*pcm
[2];
134 struct loopback_setup setup
[MAX_PCM_SUBSTREAMS
][2];
135 const char *timer_source
;
138 struct loopback_pcm
{
139 struct loopback
*loopback
;
140 struct snd_pcm_substream
*substream
;
141 struct loopback_cable
*cable
;
142 unsigned int pcm_buffer_size
;
143 unsigned int buf_pos
; /* position in buffer */
144 unsigned int silent_size
;
146 unsigned int pcm_period_size
;
147 unsigned int pcm_bps
; /* bytes per second */
148 unsigned int pcm_salign
; /* bytes per sample * channels */
149 unsigned int pcm_rate_shift
; /* rate shift value */
151 unsigned int period_update_pending
:1;
153 unsigned int irq_pos
; /* fractional IRQ position in jiffies
156 unsigned int period_size_frac
; /* period size in jiffies ticks */
157 unsigned int last_drift
;
158 unsigned long last_jiffies
;
159 /* If jiffies timer is used */
160 struct timer_list timer
;
163 static struct platform_device
*devices
[SNDRV_CARDS
];
165 static inline unsigned int byte_pos(struct loopback_pcm
*dpcm
, unsigned int x
)
167 if (dpcm
->pcm_rate_shift
== NO_PITCH
) {
170 x
= div_u64(NO_PITCH
* (unsigned long long)x
,
171 HZ
* (unsigned long long)dpcm
->pcm_rate_shift
);
173 return x
- (x
% dpcm
->pcm_salign
);
176 static inline unsigned int frac_pos(struct loopback_pcm
*dpcm
, unsigned int x
)
178 if (dpcm
->pcm_rate_shift
== NO_PITCH
) { /* no pitch */
181 x
= div_u64(dpcm
->pcm_rate_shift
* (unsigned long long)x
* HZ
,
187 static inline struct loopback_setup
*get_setup(struct loopback_pcm
*dpcm
)
189 int device
= dpcm
->substream
->pstr
->pcm
->device
;
191 if (dpcm
->substream
->stream
== SNDRV_PCM_STREAM_PLAYBACK
)
193 return &dpcm
->loopback
->setup
[dpcm
->substream
->number
][device
];
196 static inline unsigned int get_notify(struct loopback_pcm
*dpcm
)
198 return get_setup(dpcm
)->notify
;
201 static inline unsigned int get_rate_shift(struct loopback_pcm
*dpcm
)
203 return get_setup(dpcm
)->rate_shift
;
206 /* call in cable->lock */
207 static int loopback_jiffies_timer_start(struct loopback_pcm
*dpcm
)
210 unsigned int rate_shift
= get_rate_shift(dpcm
);
212 if (rate_shift
!= dpcm
->pcm_rate_shift
) {
213 dpcm
->pcm_rate_shift
= rate_shift
;
214 dpcm
->period_size_frac
= frac_pos(dpcm
, dpcm
->pcm_period_size
);
216 if (dpcm
->period_size_frac
<= dpcm
->irq_pos
) {
217 dpcm
->irq_pos
%= dpcm
->period_size_frac
;
218 dpcm
->period_update_pending
= 1;
220 tick
= dpcm
->period_size_frac
- dpcm
->irq_pos
;
221 tick
= DIV_ROUND_UP(tick
, dpcm
->pcm_bps
);
222 mod_timer(&dpcm
->timer
, jiffies
+ tick
);
227 /* call in cable->lock */
228 static int loopback_snd_timer_start(struct loopback_pcm
*dpcm
)
230 struct loopback_cable
*cable
= dpcm
->cable
;
233 /* Loopback device has to use same period as timer card. Therefore
234 * wake up for each snd_pcm_period_elapsed() call of timer card.
236 err
= snd_timer_start(cable
->snd_timer
.instance
, 1);
238 /* do not report error if trying to start but already
239 * running. For example called by opposite substream
245 pcm_err(dpcm
->substream
->pcm
,
246 "snd_timer_start(%d,%d,%d) failed with %d",
247 cable
->snd_timer
.id
.card
,
248 cable
->snd_timer
.id
.device
,
249 cable
->snd_timer
.id
.subdevice
,
256 /* call in cable->lock */
257 static inline int loopback_jiffies_timer_stop(struct loopback_pcm
*dpcm
)
259 del_timer(&dpcm
->timer
);
260 dpcm
->timer
.expires
= 0;
265 /* call in cable->lock */
266 static int loopback_snd_timer_stop(struct loopback_pcm
*dpcm
)
268 struct loopback_cable
*cable
= dpcm
->cable
;
271 /* only stop if both devices (playback and capture) are not running */
272 if (cable
->running
^ cable
->pause
)
275 err
= snd_timer_stop(cable
->snd_timer
.instance
);
277 pcm_err(dpcm
->substream
->pcm
,
278 "snd_timer_stop(%d,%d,%d) failed with %d",
279 cable
->snd_timer
.id
.card
,
280 cable
->snd_timer
.id
.device
,
281 cable
->snd_timer
.id
.subdevice
,
288 static inline int loopback_jiffies_timer_stop_sync(struct loopback_pcm
*dpcm
)
290 del_timer_sync(&dpcm
->timer
);
295 /* call in loopback->cable_lock */
296 static int loopback_snd_timer_close_cable(struct loopback_pcm
*dpcm
)
298 struct loopback_cable
*cable
= dpcm
->cable
;
300 /* snd_timer was not opened */
301 if (!cable
->snd_timer
.instance
)
304 /* will only be called from free_cable() when other stream was
305 * already closed. Other stream cannot be reopened as long as
306 * loopback->cable_lock is locked. Therefore no need to lock
309 snd_timer_close(cable
->snd_timer
.instance
);
311 /* wait till drain work has finished if requested */
312 cancel_work_sync(&cable
->snd_timer
.event_work
);
314 snd_timer_instance_free(cable
->snd_timer
.instance
);
315 memset(&cable
->snd_timer
, 0, sizeof(cable
->snd_timer
));
320 static int loopback_check_format(struct loopback_cable
*cable
, int stream
)
322 struct snd_pcm_runtime
*runtime
, *cruntime
;
323 struct loopback_setup
*setup
;
324 struct snd_card
*card
;
327 if (cable
->valid
!= CABLE_VALID_BOTH
) {
328 if (stream
== SNDRV_PCM_STREAM_PLAYBACK
)
332 runtime
= cable
->streams
[SNDRV_PCM_STREAM_PLAYBACK
]->
334 cruntime
= cable
->streams
[SNDRV_PCM_STREAM_CAPTURE
]->
336 check
= runtime
->format
!= cruntime
->format
||
337 runtime
->rate
!= cruntime
->rate
||
338 runtime
->channels
!= cruntime
->channels
;
341 if (stream
== SNDRV_PCM_STREAM_CAPTURE
) {
344 snd_pcm_stop(cable
->streams
[SNDRV_PCM_STREAM_CAPTURE
]->
345 substream
, SNDRV_PCM_STATE_DRAINING
);
347 runtime
= cable
->streams
[SNDRV_PCM_STREAM_PLAYBACK
]->
349 setup
= get_setup(cable
->streams
[SNDRV_PCM_STREAM_PLAYBACK
]);
350 card
= cable
->streams
[SNDRV_PCM_STREAM_PLAYBACK
]->loopback
->card
;
351 if (setup
->format
!= runtime
->format
) {
352 snd_ctl_notify(card
, SNDRV_CTL_EVENT_MASK_VALUE
,
354 setup
->format
= runtime
->format
;
356 if (setup
->rate
!= runtime
->rate
) {
357 snd_ctl_notify(card
, SNDRV_CTL_EVENT_MASK_VALUE
,
359 setup
->rate
= runtime
->rate
;
361 if (setup
->channels
!= runtime
->channels
) {
362 snd_ctl_notify(card
, SNDRV_CTL_EVENT_MASK_VALUE
,
363 &setup
->channels_id
);
364 setup
->channels
= runtime
->channels
;
370 static void loopback_active_notify(struct loopback_pcm
*dpcm
)
372 snd_ctl_notify(dpcm
->loopback
->card
,
373 SNDRV_CTL_EVENT_MASK_VALUE
,
374 &get_setup(dpcm
)->active_id
);
377 static int loopback_trigger(struct snd_pcm_substream
*substream
, int cmd
)
379 struct snd_pcm_runtime
*runtime
= substream
->runtime
;
380 struct loopback_pcm
*dpcm
= runtime
->private_data
;
381 struct loopback_cable
*cable
= dpcm
->cable
;
382 int err
= 0, stream
= 1 << substream
->stream
;
385 case SNDRV_PCM_TRIGGER_START
:
386 err
= loopback_check_format(cable
, substream
->stream
);
389 dpcm
->last_jiffies
= jiffies
;
390 dpcm
->pcm_rate_shift
= 0;
391 dpcm
->last_drift
= 0;
392 spin_lock(&cable
->lock
);
393 cable
->running
|= stream
;
394 cable
->pause
&= ~stream
;
395 err
= cable
->ops
->start(dpcm
);
396 spin_unlock(&cable
->lock
);
397 if (substream
->stream
== SNDRV_PCM_STREAM_PLAYBACK
)
398 loopback_active_notify(dpcm
);
400 case SNDRV_PCM_TRIGGER_STOP
:
401 spin_lock(&cable
->lock
);
402 cable
->running
&= ~stream
;
403 cable
->pause
&= ~stream
;
404 err
= cable
->ops
->stop(dpcm
);
405 spin_unlock(&cable
->lock
);
406 if (substream
->stream
== SNDRV_PCM_STREAM_PLAYBACK
)
407 loopback_active_notify(dpcm
);
409 case SNDRV_PCM_TRIGGER_PAUSE_PUSH
:
410 case SNDRV_PCM_TRIGGER_SUSPEND
:
411 spin_lock(&cable
->lock
);
412 cable
->pause
|= stream
;
413 err
= cable
->ops
->stop(dpcm
);
414 spin_unlock(&cable
->lock
);
415 if (substream
->stream
== SNDRV_PCM_STREAM_PLAYBACK
)
416 loopback_active_notify(dpcm
);
418 case SNDRV_PCM_TRIGGER_PAUSE_RELEASE
:
419 case SNDRV_PCM_TRIGGER_RESUME
:
420 spin_lock(&cable
->lock
);
421 dpcm
->last_jiffies
= jiffies
;
422 cable
->pause
&= ~stream
;
423 err
= cable
->ops
->start(dpcm
);
424 spin_unlock(&cable
->lock
);
425 if (substream
->stream
== SNDRV_PCM_STREAM_PLAYBACK
)
426 loopback_active_notify(dpcm
);
434 static void params_change(struct snd_pcm_substream
*substream
)
436 struct snd_pcm_runtime
*runtime
= substream
->runtime
;
437 struct loopback_pcm
*dpcm
= runtime
->private_data
;
438 struct loopback_cable
*cable
= dpcm
->cable
;
440 cable
->hw
.formats
= pcm_format_to_bits(runtime
->format
);
441 cable
->hw
.rate_min
= runtime
->rate
;
442 cable
->hw
.rate_max
= runtime
->rate
;
443 cable
->hw
.channels_min
= runtime
->channels
;
444 cable
->hw
.channels_max
= runtime
->channels
;
446 if (cable
->snd_timer
.instance
) {
447 cable
->hw
.period_bytes_min
=
448 frames_to_bytes(runtime
, runtime
->period_size
);
449 cable
->hw
.period_bytes_max
= cable
->hw
.period_bytes_min
;
454 static int loopback_prepare(struct snd_pcm_substream
*substream
)
456 struct snd_pcm_runtime
*runtime
= substream
->runtime
;
457 struct loopback_pcm
*dpcm
= runtime
->private_data
;
458 struct loopback_cable
*cable
= dpcm
->cable
;
459 int err
, bps
, salign
;
461 if (cable
->ops
->stop_sync
) {
462 err
= cable
->ops
->stop_sync(dpcm
);
467 salign
= (snd_pcm_format_physical_width(runtime
->format
) *
468 runtime
->channels
) / 8;
469 bps
= salign
* runtime
->rate
;
470 if (bps
<= 0 || salign
<= 0)
474 dpcm
->pcm_buffer_size
= frames_to_bytes(runtime
, runtime
->buffer_size
);
475 if (substream
->stream
== SNDRV_PCM_STREAM_CAPTURE
) {
476 /* clear capture buffer */
477 dpcm
->silent_size
= dpcm
->pcm_buffer_size
;
478 snd_pcm_format_set_silence(runtime
->format
, runtime
->dma_area
,
479 runtime
->buffer_size
* runtime
->channels
);
483 dpcm
->period_update_pending
= 0;
485 dpcm
->pcm_salign
= salign
;
486 dpcm
->pcm_period_size
= frames_to_bytes(runtime
, runtime
->period_size
);
488 mutex_lock(&dpcm
->loopback
->cable_lock
);
489 if (!(cable
->valid
& ~(1 << substream
->stream
)) ||
490 (get_setup(dpcm
)->notify
&&
491 substream
->stream
== SNDRV_PCM_STREAM_PLAYBACK
))
492 params_change(substream
);
493 cable
->valid
|= 1 << substream
->stream
;
494 mutex_unlock(&dpcm
->loopback
->cable_lock
);
499 static void clear_capture_buf(struct loopback_pcm
*dpcm
, unsigned int bytes
)
501 struct snd_pcm_runtime
*runtime
= dpcm
->substream
->runtime
;
502 char *dst
= runtime
->dma_area
;
503 unsigned int dst_off
= dpcm
->buf_pos
;
505 if (dpcm
->silent_size
>= dpcm
->pcm_buffer_size
)
507 if (dpcm
->silent_size
+ bytes
> dpcm
->pcm_buffer_size
)
508 bytes
= dpcm
->pcm_buffer_size
- dpcm
->silent_size
;
511 unsigned int size
= bytes
;
512 if (dst_off
+ size
> dpcm
->pcm_buffer_size
)
513 size
= dpcm
->pcm_buffer_size
- dst_off
;
514 snd_pcm_format_set_silence(runtime
->format
, dst
+ dst_off
,
515 bytes_to_frames(runtime
, size
) *
517 dpcm
->silent_size
+= size
;
525 static void copy_play_buf(struct loopback_pcm
*play
,
526 struct loopback_pcm
*capt
,
529 struct snd_pcm_runtime
*runtime
= play
->substream
->runtime
;
530 char *src
= runtime
->dma_area
;
531 char *dst
= capt
->substream
->runtime
->dma_area
;
532 unsigned int src_off
= play
->buf_pos
;
533 unsigned int dst_off
= capt
->buf_pos
;
534 unsigned int clear_bytes
= 0;
536 /* check if playback is draining, trim the capture copy size
537 * when our pointer is at the end of playback ring buffer */
538 if (runtime
->state
== SNDRV_PCM_STATE_DRAINING
&&
539 snd_pcm_playback_hw_avail(runtime
) < runtime
->buffer_size
) {
540 snd_pcm_uframes_t appl_ptr
, appl_ptr1
, diff
;
541 appl_ptr
= appl_ptr1
= runtime
->control
->appl_ptr
;
542 appl_ptr1
-= appl_ptr1
% runtime
->buffer_size
;
543 appl_ptr1
+= play
->buf_pos
/ play
->pcm_salign
;
544 if (appl_ptr
< appl_ptr1
)
545 appl_ptr1
-= runtime
->buffer_size
;
546 diff
= (appl_ptr
- appl_ptr1
) * play
->pcm_salign
;
548 clear_bytes
= bytes
- diff
;
554 unsigned int size
= bytes
;
555 if (src_off
+ size
> play
->pcm_buffer_size
)
556 size
= play
->pcm_buffer_size
- src_off
;
557 if (dst_off
+ size
> capt
->pcm_buffer_size
)
558 size
= capt
->pcm_buffer_size
- dst_off
;
559 memcpy(dst
+ dst_off
, src
+ src_off
, size
);
560 capt
->silent_size
= 0;
564 src_off
= (src_off
+ size
) % play
->pcm_buffer_size
;
565 dst_off
= (dst_off
+ size
) % capt
->pcm_buffer_size
;
568 if (clear_bytes
> 0) {
569 clear_capture_buf(capt
, clear_bytes
);
570 capt
->silent_size
= 0;
574 static inline unsigned int bytepos_delta(struct loopback_pcm
*dpcm
,
575 unsigned int jiffies_delta
)
577 unsigned long last_pos
;
580 last_pos
= byte_pos(dpcm
, dpcm
->irq_pos
);
581 dpcm
->irq_pos
+= jiffies_delta
* dpcm
->pcm_bps
;
582 delta
= byte_pos(dpcm
, dpcm
->irq_pos
) - last_pos
;
583 if (delta
>= dpcm
->last_drift
)
584 delta
-= dpcm
->last_drift
;
585 dpcm
->last_drift
= 0;
586 if (dpcm
->irq_pos
>= dpcm
->period_size_frac
) {
587 dpcm
->irq_pos
%= dpcm
->period_size_frac
;
588 dpcm
->period_update_pending
= 1;
593 static inline void bytepos_finish(struct loopback_pcm
*dpcm
,
596 dpcm
->buf_pos
+= delta
;
597 dpcm
->buf_pos
%= dpcm
->pcm_buffer_size
;
600 /* call in cable->lock */
601 static unsigned int loopback_jiffies_timer_pos_update
602 (struct loopback_cable
*cable
)
604 struct loopback_pcm
*dpcm_play
=
605 cable
->streams
[SNDRV_PCM_STREAM_PLAYBACK
];
606 struct loopback_pcm
*dpcm_capt
=
607 cable
->streams
[SNDRV_PCM_STREAM_CAPTURE
];
608 unsigned long delta_play
= 0, delta_capt
= 0, cur_jiffies
;
609 unsigned int running
, count1
, count2
;
611 cur_jiffies
= jiffies
;
612 running
= cable
->running
^ cable
->pause
;
613 if (running
& (1 << SNDRV_PCM_STREAM_PLAYBACK
)) {
614 delta_play
= cur_jiffies
- dpcm_play
->last_jiffies
;
615 dpcm_play
->last_jiffies
+= delta_play
;
618 if (running
& (1 << SNDRV_PCM_STREAM_CAPTURE
)) {
619 delta_capt
= cur_jiffies
- dpcm_capt
->last_jiffies
;
620 dpcm_capt
->last_jiffies
+= delta_capt
;
623 if (delta_play
== 0 && delta_capt
== 0)
626 if (delta_play
> delta_capt
) {
627 count1
= bytepos_delta(dpcm_play
, delta_play
- delta_capt
);
628 bytepos_finish(dpcm_play
, count1
);
629 delta_play
= delta_capt
;
630 } else if (delta_play
< delta_capt
) {
631 count1
= bytepos_delta(dpcm_capt
, delta_capt
- delta_play
);
632 clear_capture_buf(dpcm_capt
, count1
);
633 bytepos_finish(dpcm_capt
, count1
);
634 delta_capt
= delta_play
;
637 if (delta_play
== 0 && delta_capt
== 0)
640 /* note delta_capt == delta_play at this moment */
641 count1
= bytepos_delta(dpcm_play
, delta_play
);
642 count2
= bytepos_delta(dpcm_capt
, delta_capt
);
643 if (count1
< count2
) {
644 dpcm_capt
->last_drift
= count2
- count1
;
646 } else if (count1
> count2
) {
647 dpcm_play
->last_drift
= count1
- count2
;
649 copy_play_buf(dpcm_play
, dpcm_capt
, count1
);
650 bytepos_finish(dpcm_play
, count1
);
651 bytepos_finish(dpcm_capt
, count1
);
656 static void loopback_jiffies_timer_function(struct timer_list
*t
)
658 struct loopback_pcm
*dpcm
= from_timer(dpcm
, t
, timer
);
661 spin_lock_irqsave(&dpcm
->cable
->lock
, flags
);
662 if (loopback_jiffies_timer_pos_update(dpcm
->cable
) &
663 (1 << dpcm
->substream
->stream
)) {
664 loopback_jiffies_timer_start(dpcm
);
665 if (dpcm
->period_update_pending
) {
666 dpcm
->period_update_pending
= 0;
667 spin_unlock_irqrestore(&dpcm
->cable
->lock
, flags
);
668 /* need to unlock before calling below */
669 snd_pcm_period_elapsed(dpcm
->substream
);
673 spin_unlock_irqrestore(&dpcm
->cable
->lock
, flags
);
676 /* call in cable->lock */
677 static int loopback_snd_timer_check_resolution(struct snd_pcm_runtime
*runtime
,
678 unsigned long resolution
)
680 if (resolution
!= runtime
->timer_resolution
) {
681 struct loopback_pcm
*dpcm
= runtime
->private_data
;
682 struct loopback_cable
*cable
= dpcm
->cable
;
683 /* Worst case estimation of possible values for resolution
684 * resolution <= (512 * 1024) frames / 8kHz in nsec
685 * resolution <= 65.536.000.000 nsec
687 * period_size <= 65.536.000.000 nsec / 1000nsec/usec * 192kHz +
689 * period_size <= 12.582.912.000.000 <64bit
690 * / 1.000.000 usec/sec
692 snd_pcm_uframes_t period_size_usec
=
693 resolution
/ 1000 * runtime
->rate
;
694 /* round to nearest sample rate */
695 snd_pcm_uframes_t period_size
=
696 (period_size_usec
+ 500 * 1000) / (1000 * 1000);
698 pcm_err(dpcm
->substream
->pcm
,
699 "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.",
700 runtime
->period_size
, resolution
, period_size
,
701 cable
->snd_timer
.id
.card
,
702 cable
->snd_timer
.id
.device
,
703 cable
->snd_timer
.id
.subdevice
,
710 static void loopback_snd_timer_period_elapsed(struct loopback_cable
*cable
,
712 unsigned long resolution
)
714 struct loopback_pcm
*dpcm_play
, *dpcm_capt
;
715 struct snd_pcm_substream
*substream_play
, *substream_capt
;
716 struct snd_pcm_runtime
*valid_runtime
;
717 unsigned int running
, elapsed_bytes
;
720 spin_lock_irqsave(&cable
->lock
, flags
);
721 running
= cable
->running
^ cable
->pause
;
722 /* no need to do anything if no stream is running */
724 spin_unlock_irqrestore(&cable
->lock
, flags
);
728 dpcm_play
= cable
->streams
[SNDRV_PCM_STREAM_PLAYBACK
];
729 dpcm_capt
= cable
->streams
[SNDRV_PCM_STREAM_CAPTURE
];
731 if (event
== SNDRV_TIMER_EVENT_MSTOP
) {
733 dpcm_play
->substream
->runtime
->state
!=
734 SNDRV_PCM_STATE_DRAINING
) {
735 spin_unlock_irqrestore(&cable
->lock
, flags
);
740 substream_play
= (running
& (1 << SNDRV_PCM_STREAM_PLAYBACK
)) ?
741 dpcm_play
->substream
: NULL
;
742 substream_capt
= (running
& (1 << SNDRV_PCM_STREAM_CAPTURE
)) ?
743 dpcm_capt
->substream
: NULL
;
744 valid_runtime
= (running
& (1 << SNDRV_PCM_STREAM_PLAYBACK
)) ?
745 dpcm_play
->substream
->runtime
:
746 dpcm_capt
->substream
->runtime
;
748 /* resolution is only valid for SNDRV_TIMER_EVENT_TICK events */
749 if (event
== SNDRV_TIMER_EVENT_TICK
) {
750 /* The hardware rules guarantee that playback and capture period
751 * are the same. Therefore only one device has to be checked
754 if (loopback_snd_timer_check_resolution(valid_runtime
,
756 spin_unlock_irqrestore(&cable
->lock
, flags
);
758 snd_pcm_stop_xrun(substream_play
);
760 snd_pcm_stop_xrun(substream_capt
);
765 elapsed_bytes
= frames_to_bytes(valid_runtime
,
766 valid_runtime
->period_size
);
767 /* The same timer interrupt is used for playback and capture device */
768 if ((running
& (1 << SNDRV_PCM_STREAM_PLAYBACK
)) &&
769 (running
& (1 << SNDRV_PCM_STREAM_CAPTURE
))) {
770 copy_play_buf(dpcm_play
, dpcm_capt
, elapsed_bytes
);
771 bytepos_finish(dpcm_play
, elapsed_bytes
);
772 bytepos_finish(dpcm_capt
, elapsed_bytes
);
773 } else if (running
& (1 << SNDRV_PCM_STREAM_PLAYBACK
)) {
774 bytepos_finish(dpcm_play
, elapsed_bytes
);
775 } else if (running
& (1 << SNDRV_PCM_STREAM_CAPTURE
)) {
776 clear_capture_buf(dpcm_capt
, elapsed_bytes
);
777 bytepos_finish(dpcm_capt
, elapsed_bytes
);
779 spin_unlock_irqrestore(&cable
->lock
, flags
);
782 snd_pcm_period_elapsed(substream_play
);
784 snd_pcm_period_elapsed(substream_capt
);
787 static void loopback_snd_timer_function(struct snd_timer_instance
*timeri
,
788 unsigned long resolution
,
791 struct loopback_cable
*cable
= timeri
->callback_data
;
793 loopback_snd_timer_period_elapsed(cable
, SNDRV_TIMER_EVENT_TICK
,
797 static void loopback_snd_timer_work(struct work_struct
*work
)
799 struct loopback_cable
*cable
;
801 cable
= container_of(work
, struct loopback_cable
, snd_timer
.event_work
);
802 loopback_snd_timer_period_elapsed(cable
, SNDRV_TIMER_EVENT_MSTOP
, 0);
805 static void loopback_snd_timer_event(struct snd_timer_instance
*timeri
,
807 struct timespec64
*tstamp
,
808 unsigned long resolution
)
810 /* Do not lock cable->lock here because timer->lock is already hold.
811 * There are other functions which first lock cable->lock and than
814 * spin_lock(&cable->lock)
815 * loopback_snd_timer_start()
817 * spin_lock(&timer->lock)
818 * Therefore when using the oposit order of locks here it could result
822 if (event
== SNDRV_TIMER_EVENT_MSTOP
) {
823 struct loopback_cable
*cable
= timeri
->callback_data
;
825 /* sound card of the timer was stopped. Therefore there will not
826 * be any further timer callbacks. Due to this forward audio
827 * data from here if in draining state. When still in running
828 * state the streaming will be aborted by the usual timeout. It
829 * should not be aborted here because may be the timer sound
830 * card does only a recovery and the timer is back soon.
831 * This work triggers loopback_snd_timer_work()
833 schedule_work(&cable
->snd_timer
.event_work
);
837 static void loopback_jiffies_timer_dpcm_info(struct loopback_pcm
*dpcm
,
838 struct snd_info_buffer
*buffer
)
840 snd_iprintf(buffer
, " update_pending:\t%u\n",
841 dpcm
->period_update_pending
);
842 snd_iprintf(buffer
, " irq_pos:\t\t%u\n", dpcm
->irq_pos
);
843 snd_iprintf(buffer
, " period_frac:\t%u\n", dpcm
->period_size_frac
);
844 snd_iprintf(buffer
, " last_jiffies:\t%lu (%lu)\n",
845 dpcm
->last_jiffies
, jiffies
);
846 snd_iprintf(buffer
, " timer_expires:\t%lu\n", dpcm
->timer
.expires
);
849 static void loopback_snd_timer_dpcm_info(struct loopback_pcm
*dpcm
,
850 struct snd_info_buffer
*buffer
)
852 struct loopback_cable
*cable
= dpcm
->cable
;
854 snd_iprintf(buffer
, " sound timer:\thw:%d,%d,%d\n",
855 cable
->snd_timer
.id
.card
,
856 cable
->snd_timer
.id
.device
,
857 cable
->snd_timer
.id
.subdevice
);
858 snd_iprintf(buffer
, " timer open:\t\t%s\n",
859 (cable
->snd_timer
.stream
== SNDRV_PCM_STREAM_CAPTURE
) ?
860 "capture" : "playback");
863 static snd_pcm_uframes_t
loopback_pointer(struct snd_pcm_substream
*substream
)
865 struct snd_pcm_runtime
*runtime
= substream
->runtime
;
866 struct loopback_pcm
*dpcm
= runtime
->private_data
;
867 snd_pcm_uframes_t pos
;
869 spin_lock(&dpcm
->cable
->lock
);
870 if (dpcm
->cable
->ops
->pos_update
)
871 dpcm
->cable
->ops
->pos_update(dpcm
->cable
);
873 spin_unlock(&dpcm
->cable
->lock
);
874 return bytes_to_frames(runtime
, pos
);
877 static const struct snd_pcm_hardware loopback_pcm_hardware
=
879 .info
= (SNDRV_PCM_INFO_INTERLEAVED
| SNDRV_PCM_INFO_MMAP
|
880 SNDRV_PCM_INFO_MMAP_VALID
| SNDRV_PCM_INFO_PAUSE
|
881 SNDRV_PCM_INFO_RESUME
),
882 .formats
= (SNDRV_PCM_FMTBIT_S16_LE
| SNDRV_PCM_FMTBIT_S16_BE
|
883 SNDRV_PCM_FMTBIT_S24_LE
| SNDRV_PCM_FMTBIT_S24_BE
|
884 SNDRV_PCM_FMTBIT_S24_3LE
| SNDRV_PCM_FMTBIT_S24_3BE
|
885 SNDRV_PCM_FMTBIT_S32_LE
| SNDRV_PCM_FMTBIT_S32_BE
|
886 SNDRV_PCM_FMTBIT_FLOAT_LE
| SNDRV_PCM_FMTBIT_FLOAT_BE
),
887 .rates
= SNDRV_PCM_RATE_CONTINUOUS
| SNDRV_PCM_RATE_8000_192000
,
892 .buffer_bytes_max
= 2 * 1024 * 1024,
893 .period_bytes_min
= 64,
894 /* note check overflow in frac_pos() using pcm_rate_shift before
895 changing period_bytes_max value */
896 .period_bytes_max
= 1024 * 1024,
902 static void loopback_runtime_free(struct snd_pcm_runtime
*runtime
)
904 struct loopback_pcm
*dpcm
= runtime
->private_data
;
908 static int loopback_hw_free(struct snd_pcm_substream
*substream
)
910 struct snd_pcm_runtime
*runtime
= substream
->runtime
;
911 struct loopback_pcm
*dpcm
= runtime
->private_data
;
912 struct loopback_cable
*cable
= dpcm
->cable
;
914 mutex_lock(&dpcm
->loopback
->cable_lock
);
915 cable
->valid
&= ~(1 << substream
->stream
);
916 mutex_unlock(&dpcm
->loopback
->cable_lock
);
920 static unsigned int get_cable_index(struct snd_pcm_substream
*substream
)
922 if (!substream
->pcm
->device
)
923 return substream
->stream
;
925 return !substream
->stream
;
928 static int rule_format(struct snd_pcm_hw_params
*params
,
929 struct snd_pcm_hw_rule
*rule
)
931 struct loopback_pcm
*dpcm
= rule
->private;
932 struct loopback_cable
*cable
= dpcm
->cable
;
936 mutex_lock(&dpcm
->loopback
->cable_lock
);
937 m
.bits
[0] = (u_int32_t
)cable
->hw
.formats
;
938 m
.bits
[1] = (u_int32_t
)(cable
->hw
.formats
>> 32);
939 mutex_unlock(&dpcm
->loopback
->cable_lock
);
940 return snd_mask_refine(hw_param_mask(params
, rule
->var
), &m
);
943 static int rule_rate(struct snd_pcm_hw_params
*params
,
944 struct snd_pcm_hw_rule
*rule
)
946 struct loopback_pcm
*dpcm
= rule
->private;
947 struct loopback_cable
*cable
= dpcm
->cable
;
948 struct snd_interval t
;
950 mutex_lock(&dpcm
->loopback
->cable_lock
);
951 t
.min
= cable
->hw
.rate_min
;
952 t
.max
= cable
->hw
.rate_max
;
953 mutex_unlock(&dpcm
->loopback
->cable_lock
);
954 t
.openmin
= t
.openmax
= 0;
956 return snd_interval_refine(hw_param_interval(params
, rule
->var
), &t
);
959 static int rule_channels(struct snd_pcm_hw_params
*params
,
960 struct snd_pcm_hw_rule
*rule
)
962 struct loopback_pcm
*dpcm
= rule
->private;
963 struct loopback_cable
*cable
= dpcm
->cable
;
964 struct snd_interval t
;
966 mutex_lock(&dpcm
->loopback
->cable_lock
);
967 t
.min
= cable
->hw
.channels_min
;
968 t
.max
= cable
->hw
.channels_max
;
969 mutex_unlock(&dpcm
->loopback
->cable_lock
);
970 t
.openmin
= t
.openmax
= 0;
972 return snd_interval_refine(hw_param_interval(params
, rule
->var
), &t
);
975 static int rule_period_bytes(struct snd_pcm_hw_params
*params
,
976 struct snd_pcm_hw_rule
*rule
)
978 struct loopback_pcm
*dpcm
= rule
->private;
979 struct loopback_cable
*cable
= dpcm
->cable
;
980 struct snd_interval t
;
982 mutex_lock(&dpcm
->loopback
->cable_lock
);
983 t
.min
= cable
->hw
.period_bytes_min
;
984 t
.max
= cable
->hw
.period_bytes_max
;
985 mutex_unlock(&dpcm
->loopback
->cable_lock
);
989 return snd_interval_refine(hw_param_interval(params
, rule
->var
), &t
);
992 static void free_cable(struct snd_pcm_substream
*substream
)
994 struct loopback
*loopback
= substream
->private_data
;
995 int dev
= get_cable_index(substream
);
996 struct loopback_cable
*cable
;
998 cable
= loopback
->cables
[substream
->number
][dev
];
1001 if (cable
->streams
[!substream
->stream
]) {
1002 /* other stream is still alive */
1003 spin_lock_irq(&cable
->lock
);
1004 cable
->streams
[substream
->stream
] = NULL
;
1005 spin_unlock_irq(&cable
->lock
);
1007 struct loopback_pcm
*dpcm
= substream
->runtime
->private_data
;
1009 if (cable
->ops
&& cable
->ops
->close_cable
&& dpcm
)
1010 cable
->ops
->close_cable(dpcm
);
1011 /* free the cable */
1012 loopback
->cables
[substream
->number
][dev
] = NULL
;
1017 static int loopback_jiffies_timer_open(struct loopback_pcm
*dpcm
)
1019 timer_setup(&dpcm
->timer
, loopback_jiffies_timer_function
, 0);
1024 static const struct loopback_ops loopback_jiffies_timer_ops
= {
1025 .open
= loopback_jiffies_timer_open
,
1026 .start
= loopback_jiffies_timer_start
,
1027 .stop
= loopback_jiffies_timer_stop
,
1028 .stop_sync
= loopback_jiffies_timer_stop_sync
,
1029 .close_substream
= loopback_jiffies_timer_stop_sync
,
1030 .pos_update
= loopback_jiffies_timer_pos_update
,
1031 .dpcm_info
= loopback_jiffies_timer_dpcm_info
,
1034 static int loopback_parse_timer_id(const char *str
,
1035 struct snd_timer_id
*tid
)
1037 /* [<pref>:](<card name>|<card idx>)[{.,}<dev idx>[{.,}<subdev idx>]] */
1038 const char * const sep_dev
= ".,";
1039 const char * const sep_pref
= ":";
1040 const char *name
= str
;
1041 char *sep
, save
= '\0';
1042 int card_idx
= 0, dev
= 0, subdev
= 0;
1045 sep
= strpbrk(str
, sep_pref
);
1048 sep
= strpbrk(name
, sep_dev
);
1053 err
= kstrtoint(name
, 0, &card_idx
);
1054 if (err
== -EINVAL
) {
1055 /* Must be the name, not number */
1056 for (card_idx
= 0; card_idx
< snd_ecards_limit
; card_idx
++) {
1057 struct snd_card
*card
= snd_card_ref(card_idx
);
1060 if (!strcmp(card
->id
, name
))
1062 snd_card_unref(card
);
1071 char *sep2
, save2
= '\0';
1073 sep2
= strpbrk(sep
+ 1, sep_dev
);
1078 err
= kstrtoint(sep
+ 1, 0, &dev
);
1082 err
= kstrtoint(sep2
+ 1, 0, &subdev
);
1087 tid
->card
= card_idx
;
1089 tid
->subdevice
= subdev
;
1094 /* call in loopback->cable_lock */
1095 static int loopback_snd_timer_open(struct loopback_pcm
*dpcm
)
1098 struct snd_timer_id tid
= {
1099 .dev_class
= SNDRV_TIMER_CLASS_PCM
,
1100 .dev_sclass
= SNDRV_TIMER_SCLASS_APPLICATION
,
1102 struct snd_timer_instance
*timeri
;
1103 struct loopback_cable
*cable
= dpcm
->cable
;
1105 /* check if timer was already opened. It is only opened once
1106 * per playback and capture subdevice (aka cable).
1108 if (cable
->snd_timer
.instance
)
1111 err
= loopback_parse_timer_id(dpcm
->loopback
->timer_source
, &tid
);
1113 pcm_err(dpcm
->substream
->pcm
,
1114 "Parsing timer source \'%s\' failed with %d",
1115 dpcm
->loopback
->timer_source
, err
);
1119 cable
->snd_timer
.stream
= dpcm
->substream
->stream
;
1120 cable
->snd_timer
.id
= tid
;
1122 timeri
= snd_timer_instance_new(dpcm
->loopback
->card
->id
);
1127 /* The callback has to be called from another work. If
1128 * SNDRV_TIMER_IFLG_FAST is specified it will be called from the
1129 * snd_pcm_period_elapsed() call of the selected sound card.
1130 * snd_pcm_period_elapsed() helds snd_pcm_stream_lock_irqsave().
1131 * Due to our callback loopback_snd_timer_function() also calls
1132 * snd_pcm_period_elapsed() which calls snd_pcm_stream_lock_irqsave().
1133 * This would end up in a dead lock.
1135 timeri
->flags
|= SNDRV_TIMER_IFLG_AUTO
;
1136 timeri
->callback
= loopback_snd_timer_function
;
1137 timeri
->callback_data
= (void *)cable
;
1138 timeri
->ccallback
= loopback_snd_timer_event
;
1140 /* initialise a work used for draining */
1141 INIT_WORK(&cable
->snd_timer
.event_work
, loopback_snd_timer_work
);
1143 /* The mutex loopback->cable_lock is kept locked.
1144 * Therefore snd_timer_open() cannot be called a second time
1145 * by the other device of the same cable.
1146 * Therefore the following issue cannot happen:
1147 * [proc1] Call loopback_timer_open() ->
1148 * Unlock cable->lock for snd_timer_close/open() call
1149 * [proc2] Call loopback_timer_open() -> snd_timer_open(),
1151 * [proc1] Call snd_timer_open() and overwrite running timer
1154 err
= snd_timer_open(timeri
, &cable
->snd_timer
.id
, current
->pid
);
1156 pcm_err(dpcm
->substream
->pcm
,
1157 "snd_timer_open (%d,%d,%d) failed with %d",
1158 cable
->snd_timer
.id
.card
,
1159 cable
->snd_timer
.id
.device
,
1160 cable
->snd_timer
.id
.subdevice
,
1162 snd_timer_instance_free(timeri
);
1166 cable
->snd_timer
.instance
= timeri
;
1172 /* stop_sync() is not required for sound timer because it does not need to be
1173 * restarted in loopback_prepare() on Xrun recovery
1175 static const struct loopback_ops loopback_snd_timer_ops
= {
1176 .open
= loopback_snd_timer_open
,
1177 .start
= loopback_snd_timer_start
,
1178 .stop
= loopback_snd_timer_stop
,
1179 .close_cable
= loopback_snd_timer_close_cable
,
1180 .dpcm_info
= loopback_snd_timer_dpcm_info
,
1183 static int loopback_open(struct snd_pcm_substream
*substream
)
1185 struct snd_pcm_runtime
*runtime
= substream
->runtime
;
1186 struct loopback
*loopback
= substream
->private_data
;
1187 struct loopback_pcm
*dpcm
;
1188 struct loopback_cable
*cable
= NULL
;
1190 int dev
= get_cable_index(substream
);
1192 mutex_lock(&loopback
->cable_lock
);
1193 dpcm
= kzalloc(sizeof(*dpcm
), GFP_KERNEL
);
1198 dpcm
->loopback
= loopback
;
1199 dpcm
->substream
= substream
;
1201 cable
= loopback
->cables
[substream
->number
][dev
];
1203 cable
= kzalloc(sizeof(*cable
), GFP_KERNEL
);
1208 spin_lock_init(&cable
->lock
);
1209 cable
->hw
= loopback_pcm_hardware
;
1210 if (loopback
->timer_source
)
1211 cable
->ops
= &loopback_snd_timer_ops
;
1213 cable
->ops
= &loopback_jiffies_timer_ops
;
1214 loopback
->cables
[substream
->number
][dev
] = cable
;
1216 dpcm
->cable
= cable
;
1217 runtime
->private_data
= dpcm
;
1219 if (cable
->ops
->open
) {
1220 err
= cable
->ops
->open(dpcm
);
1225 snd_pcm_hw_constraint_integer(runtime
, SNDRV_PCM_HW_PARAM_PERIODS
);
1227 /* use dynamic rules based on actual runtime->hw values */
1228 /* note that the default rules created in the PCM midlevel code */
1229 /* are cached -> they do not reflect the actual state */
1230 err
= snd_pcm_hw_rule_add(runtime
, 0,
1231 SNDRV_PCM_HW_PARAM_FORMAT
,
1233 SNDRV_PCM_HW_PARAM_FORMAT
, -1);
1236 err
= snd_pcm_hw_rule_add(runtime
, 0,
1237 SNDRV_PCM_HW_PARAM_RATE
,
1239 SNDRV_PCM_HW_PARAM_RATE
, -1);
1242 err
= snd_pcm_hw_rule_add(runtime
, 0,
1243 SNDRV_PCM_HW_PARAM_CHANNELS
,
1244 rule_channels
, dpcm
,
1245 SNDRV_PCM_HW_PARAM_CHANNELS
, -1);
1249 /* In case of sound timer the period time of both devices of the same
1250 * loop has to be the same.
1251 * This rule only takes effect if a sound timer was chosen
1253 if (cable
->snd_timer
.instance
) {
1254 err
= snd_pcm_hw_rule_add(runtime
, 0,
1255 SNDRV_PCM_HW_PARAM_PERIOD_BYTES
,
1256 rule_period_bytes
, dpcm
,
1257 SNDRV_PCM_HW_PARAM_PERIOD_BYTES
, -1);
1262 /* loopback_runtime_free() has not to be called if kfree(dpcm) was
1263 * already called here. Otherwise it will end up with a double free.
1265 runtime
->private_free
= loopback_runtime_free
;
1266 if (get_notify(dpcm
))
1267 runtime
->hw
= loopback_pcm_hardware
;
1269 runtime
->hw
= cable
->hw
;
1271 spin_lock_irq(&cable
->lock
);
1272 cable
->streams
[substream
->stream
] = dpcm
;
1273 spin_unlock_irq(&cable
->lock
);
1277 free_cable(substream
);
1280 mutex_unlock(&loopback
->cable_lock
);
1284 static int loopback_close(struct snd_pcm_substream
*substream
)
1286 struct loopback
*loopback
= substream
->private_data
;
1287 struct loopback_pcm
*dpcm
= substream
->runtime
->private_data
;
1290 if (dpcm
->cable
->ops
->close_substream
)
1291 err
= dpcm
->cable
->ops
->close_substream(dpcm
);
1292 mutex_lock(&loopback
->cable_lock
);
1293 free_cable(substream
);
1294 mutex_unlock(&loopback
->cable_lock
);
1298 static const struct snd_pcm_ops loopback_pcm_ops
= {
1299 .open
= loopback_open
,
1300 .close
= loopback_close
,
1301 .hw_free
= loopback_hw_free
,
1302 .prepare
= loopback_prepare
,
1303 .trigger
= loopback_trigger
,
1304 .pointer
= loopback_pointer
,
1307 static int loopback_pcm_new(struct loopback
*loopback
,
1308 int device
, int substreams
)
1310 struct snd_pcm
*pcm
;
1313 err
= snd_pcm_new(loopback
->card
, "Loopback PCM", device
,
1314 substreams
, substreams
, &pcm
);
1317 snd_pcm_set_ops(pcm
, SNDRV_PCM_STREAM_PLAYBACK
, &loopback_pcm_ops
);
1318 snd_pcm_set_ops(pcm
, SNDRV_PCM_STREAM_CAPTURE
, &loopback_pcm_ops
);
1319 snd_pcm_set_managed_buffer_all(pcm
, SNDRV_DMA_TYPE_VMALLOC
, NULL
, 0, 0);
1321 pcm
->private_data
= loopback
;
1322 pcm
->info_flags
= 0;
1323 strcpy(pcm
->name
, "Loopback PCM");
1325 loopback
->pcm
[device
] = pcm
;
1329 static int loopback_rate_shift_info(struct snd_kcontrol
*kcontrol
,
1330 struct snd_ctl_elem_info
*uinfo
)
1332 uinfo
->type
= SNDRV_CTL_ELEM_TYPE_INTEGER
;
1334 uinfo
->value
.integer
.min
= 80000;
1335 uinfo
->value
.integer
.max
= 120000;
1336 uinfo
->value
.integer
.step
= 1;
1340 static int loopback_rate_shift_get(struct snd_kcontrol
*kcontrol
,
1341 struct snd_ctl_elem_value
*ucontrol
)
1343 struct loopback
*loopback
= snd_kcontrol_chip(kcontrol
);
1345 mutex_lock(&loopback
->cable_lock
);
1346 ucontrol
->value
.integer
.value
[0] =
1347 loopback
->setup
[kcontrol
->id
.subdevice
]
1348 [kcontrol
->id
.device
].rate_shift
;
1349 mutex_unlock(&loopback
->cable_lock
);
1353 static int loopback_rate_shift_put(struct snd_kcontrol
*kcontrol
,
1354 struct snd_ctl_elem_value
*ucontrol
)
1356 struct loopback
*loopback
= snd_kcontrol_chip(kcontrol
);
1360 val
= ucontrol
->value
.integer
.value
[0];
1365 mutex_lock(&loopback
->cable_lock
);
1366 if (val
!= loopback
->setup
[kcontrol
->id
.subdevice
]
1367 [kcontrol
->id
.device
].rate_shift
) {
1368 loopback
->setup
[kcontrol
->id
.subdevice
]
1369 [kcontrol
->id
.device
].rate_shift
= val
;
1372 mutex_unlock(&loopback
->cable_lock
);
1376 static int loopback_notify_get(struct snd_kcontrol
*kcontrol
,
1377 struct snd_ctl_elem_value
*ucontrol
)
1379 struct loopback
*loopback
= snd_kcontrol_chip(kcontrol
);
1381 mutex_lock(&loopback
->cable_lock
);
1382 ucontrol
->value
.integer
.value
[0] =
1383 loopback
->setup
[kcontrol
->id
.subdevice
]
1384 [kcontrol
->id
.device
].notify
;
1385 mutex_unlock(&loopback
->cable_lock
);
1389 static int loopback_notify_put(struct snd_kcontrol
*kcontrol
,
1390 struct snd_ctl_elem_value
*ucontrol
)
1392 struct loopback
*loopback
= snd_kcontrol_chip(kcontrol
);
1396 val
= ucontrol
->value
.integer
.value
[0] ? 1 : 0;
1397 mutex_lock(&loopback
->cable_lock
);
1398 if (val
!= loopback
->setup
[kcontrol
->id
.subdevice
]
1399 [kcontrol
->id
.device
].notify
) {
1400 loopback
->setup
[kcontrol
->id
.subdevice
]
1401 [kcontrol
->id
.device
].notify
= val
;
1404 mutex_unlock(&loopback
->cable_lock
);
1408 static int loopback_active_get(struct snd_kcontrol
*kcontrol
,
1409 struct snd_ctl_elem_value
*ucontrol
)
1411 struct loopback
*loopback
= snd_kcontrol_chip(kcontrol
);
1412 struct loopback_cable
*cable
;
1414 unsigned int val
= 0;
1416 mutex_lock(&loopback
->cable_lock
);
1417 cable
= loopback
->cables
[kcontrol
->id
.subdevice
][kcontrol
->id
.device
^ 1];
1418 if (cable
!= NULL
) {
1419 unsigned int running
= cable
->running
^ cable
->pause
;
1421 val
= (running
& (1 << SNDRV_PCM_STREAM_PLAYBACK
)) ? 1 : 0;
1423 mutex_unlock(&loopback
->cable_lock
);
1424 ucontrol
->value
.integer
.value
[0] = val
;
1428 static int loopback_format_info(struct snd_kcontrol
*kcontrol
,
1429 struct snd_ctl_elem_info
*uinfo
)
1431 uinfo
->type
= SNDRV_CTL_ELEM_TYPE_INTEGER
;
1433 uinfo
->value
.integer
.min
= 0;
1434 uinfo
->value
.integer
.max
= (__force
int)SNDRV_PCM_FORMAT_LAST
;
1435 uinfo
->value
.integer
.step
= 1;
1439 static int loopback_format_get(struct snd_kcontrol
*kcontrol
,
1440 struct snd_ctl_elem_value
*ucontrol
)
1442 struct loopback
*loopback
= snd_kcontrol_chip(kcontrol
);
1444 ucontrol
->value
.integer
.value
[0] =
1445 (__force
int)loopback
->setup
[kcontrol
->id
.subdevice
]
1446 [kcontrol
->id
.device
].format
;
1450 static int loopback_rate_info(struct snd_kcontrol
*kcontrol
,
1451 struct snd_ctl_elem_info
*uinfo
)
1453 uinfo
->type
= SNDRV_CTL_ELEM_TYPE_INTEGER
;
1455 uinfo
->value
.integer
.min
= 0;
1456 uinfo
->value
.integer
.max
= 192000;
1457 uinfo
->value
.integer
.step
= 1;
1461 static int loopback_rate_get(struct snd_kcontrol
*kcontrol
,
1462 struct snd_ctl_elem_value
*ucontrol
)
1464 struct loopback
*loopback
= snd_kcontrol_chip(kcontrol
);
1466 mutex_lock(&loopback
->cable_lock
);
1467 ucontrol
->value
.integer
.value
[0] =
1468 loopback
->setup
[kcontrol
->id
.subdevice
]
1469 [kcontrol
->id
.device
].rate
;
1470 mutex_unlock(&loopback
->cable_lock
);
1474 static int loopback_channels_info(struct snd_kcontrol
*kcontrol
,
1475 struct snd_ctl_elem_info
*uinfo
)
1477 uinfo
->type
= SNDRV_CTL_ELEM_TYPE_INTEGER
;
1479 uinfo
->value
.integer
.min
= 1;
1480 uinfo
->value
.integer
.max
= 1024;
1481 uinfo
->value
.integer
.step
= 1;
1485 static int loopback_channels_get(struct snd_kcontrol
*kcontrol
,
1486 struct snd_ctl_elem_value
*ucontrol
)
1488 struct loopback
*loopback
= snd_kcontrol_chip(kcontrol
);
1490 mutex_lock(&loopback
->cable_lock
);
1491 ucontrol
->value
.integer
.value
[0] =
1492 loopback
->setup
[kcontrol
->id
.subdevice
]
1493 [kcontrol
->id
.device
].channels
;
1494 mutex_unlock(&loopback
->cable_lock
);
1498 static const struct snd_kcontrol_new loopback_controls
[] = {
1500 .iface
= SNDRV_CTL_ELEM_IFACE_PCM
,
1501 .name
= "PCM Rate Shift 100000",
1502 .info
= loopback_rate_shift_info
,
1503 .get
= loopback_rate_shift_get
,
1504 .put
= loopback_rate_shift_put
,
1507 .iface
= SNDRV_CTL_ELEM_IFACE_PCM
,
1508 .name
= "PCM Notify",
1509 .info
= snd_ctl_boolean_mono_info
,
1510 .get
= loopback_notify_get
,
1511 .put
= loopback_notify_put
,
1513 #define ACTIVE_IDX 2
1515 .access
= SNDRV_CTL_ELEM_ACCESS_READ
,
1516 .iface
= SNDRV_CTL_ELEM_IFACE_PCM
,
1517 .name
= "PCM Slave Active",
1518 .info
= snd_ctl_boolean_mono_info
,
1519 .get
= loopback_active_get
,
1521 #define FORMAT_IDX 3
1523 .access
= SNDRV_CTL_ELEM_ACCESS_READ
,
1524 .iface
= SNDRV_CTL_ELEM_IFACE_PCM
,
1525 .name
= "PCM Slave Format",
1526 .info
= loopback_format_info
,
1527 .get
= loopback_format_get
1531 .access
= SNDRV_CTL_ELEM_ACCESS_READ
,
1532 .iface
= SNDRV_CTL_ELEM_IFACE_PCM
,
1533 .name
= "PCM Slave Rate",
1534 .info
= loopback_rate_info
,
1535 .get
= loopback_rate_get
1537 #define CHANNELS_IDX 5
1539 .access
= SNDRV_CTL_ELEM_ACCESS_READ
,
1540 .iface
= SNDRV_CTL_ELEM_IFACE_PCM
,
1541 .name
= "PCM Slave Channels",
1542 .info
= loopback_channels_info
,
1543 .get
= loopback_channels_get
1547 static int loopback_mixer_new(struct loopback
*loopback
, int notify
)
1549 struct snd_card
*card
= loopback
->card
;
1550 struct snd_pcm
*pcm
;
1551 struct snd_kcontrol
*kctl
;
1552 struct loopback_setup
*setup
;
1553 int err
, dev
, substr
, substr_count
, idx
;
1555 strcpy(card
->mixername
, "Loopback Mixer");
1556 for (dev
= 0; dev
< 2; dev
++) {
1557 pcm
= loopback
->pcm
[dev
];
1559 pcm
->streams
[SNDRV_PCM_STREAM_CAPTURE
].substream_count
;
1560 for (substr
= 0; substr
< substr_count
; substr
++) {
1561 setup
= &loopback
->setup
[substr
][dev
];
1562 setup
->notify
= notify
;
1563 setup
->rate_shift
= NO_PITCH
;
1564 setup
->format
= SNDRV_PCM_FORMAT_S16_LE
;
1565 setup
->rate
= 48000;
1566 setup
->channels
= 2;
1567 for (idx
= 0; idx
< ARRAY_SIZE(loopback_controls
);
1569 kctl
= snd_ctl_new1(&loopback_controls
[idx
],
1573 kctl
->id
.device
= dev
;
1574 kctl
->id
.subdevice
= substr
;
1576 /* Add the control before copying the id so that
1577 * the numid field of the id is set in the copy.
1579 err
= snd_ctl_add(card
, kctl
);
1585 setup
->active_id
= kctl
->id
;
1588 setup
->format_id
= kctl
->id
;
1591 setup
->rate_id
= kctl
->id
;
1594 setup
->channels_id
= kctl
->id
;
1605 static void print_dpcm_info(struct snd_info_buffer
*buffer
,
1606 struct loopback_pcm
*dpcm
,
1609 snd_iprintf(buffer
, " %s\n", id
);
1611 snd_iprintf(buffer
, " inactive\n");
1614 snd_iprintf(buffer
, " buffer_size:\t%u\n", dpcm
->pcm_buffer_size
);
1615 snd_iprintf(buffer
, " buffer_pos:\t\t%u\n", dpcm
->buf_pos
);
1616 snd_iprintf(buffer
, " silent_size:\t%u\n", dpcm
->silent_size
);
1617 snd_iprintf(buffer
, " period_size:\t%u\n", dpcm
->pcm_period_size
);
1618 snd_iprintf(buffer
, " bytes_per_sec:\t%u\n", dpcm
->pcm_bps
);
1619 snd_iprintf(buffer
, " sample_align:\t%u\n", dpcm
->pcm_salign
);
1620 snd_iprintf(buffer
, " rate_shift:\t\t%u\n", dpcm
->pcm_rate_shift
);
1621 if (dpcm
->cable
->ops
->dpcm_info
)
1622 dpcm
->cable
->ops
->dpcm_info(dpcm
, buffer
);
1625 static void print_substream_info(struct snd_info_buffer
*buffer
,
1626 struct loopback
*loopback
,
1630 struct loopback_cable
*cable
= loopback
->cables
[sub
][num
];
1632 snd_iprintf(buffer
, "Cable %i substream %i:\n", num
, sub
);
1633 if (cable
== NULL
) {
1634 snd_iprintf(buffer
, " inactive\n");
1637 snd_iprintf(buffer
, " valid: %u\n", cable
->valid
);
1638 snd_iprintf(buffer
, " running: %u\n", cable
->running
);
1639 snd_iprintf(buffer
, " pause: %u\n", cable
->pause
);
1640 print_dpcm_info(buffer
, cable
->streams
[0], "Playback");
1641 print_dpcm_info(buffer
, cable
->streams
[1], "Capture");
1644 static void print_cable_info(struct snd_info_entry
*entry
,
1645 struct snd_info_buffer
*buffer
)
1647 struct loopback
*loopback
= entry
->private_data
;
1650 mutex_lock(&loopback
->cable_lock
);
1651 num
= entry
->name
[strlen(entry
->name
)-1];
1652 num
= num
== '0' ? 0 : 1;
1653 for (sub
= 0; sub
< MAX_PCM_SUBSTREAMS
; sub
++)
1654 print_substream_info(buffer
, loopback
, sub
, num
);
1655 mutex_unlock(&loopback
->cable_lock
);
1658 static int loopback_cable_proc_new(struct loopback
*loopback
, int cidx
)
1662 snprintf(name
, sizeof(name
), "cable#%d", cidx
);
1663 return snd_card_ro_proc_new(loopback
->card
, name
, loopback
,
1667 static void loopback_set_timer_source(struct loopback
*loopback
,
1670 if (loopback
->timer_source
) {
1671 devm_kfree(loopback
->card
->dev
, loopback
->timer_source
);
1672 loopback
->timer_source
= NULL
;
1674 if (value
&& *value
)
1675 loopback
->timer_source
= devm_kstrdup(loopback
->card
->dev
,
1679 static void print_timer_source_info(struct snd_info_entry
*entry
,
1680 struct snd_info_buffer
*buffer
)
1682 struct loopback
*loopback
= entry
->private_data
;
1684 mutex_lock(&loopback
->cable_lock
);
1685 snd_iprintf(buffer
, "%s\n",
1686 loopback
->timer_source
? loopback
->timer_source
: "");
1687 mutex_unlock(&loopback
->cable_lock
);
1690 static void change_timer_source_info(struct snd_info_entry
*entry
,
1691 struct snd_info_buffer
*buffer
)
1693 struct loopback
*loopback
= entry
->private_data
;
1696 mutex_lock(&loopback
->cable_lock
);
1697 if (!snd_info_get_line(buffer
, line
, sizeof(line
)))
1698 loopback_set_timer_source(loopback
, strim(line
));
1699 mutex_unlock(&loopback
->cable_lock
);
1702 static int loopback_timer_source_proc_new(struct loopback
*loopback
)
1704 return snd_card_rw_proc_new(loopback
->card
, "timer_source", loopback
,
1705 print_timer_source_info
,
1706 change_timer_source_info
);
1709 static int loopback_probe(struct platform_device
*devptr
)
1711 struct snd_card
*card
;
1712 struct loopback
*loopback
;
1713 int dev
= devptr
->id
;
1716 err
= snd_devm_card_new(&devptr
->dev
, index
[dev
], id
[dev
], THIS_MODULE
,
1717 sizeof(struct loopback
), &card
);
1720 loopback
= card
->private_data
;
1722 if (pcm_substreams
[dev
] < 1)
1723 pcm_substreams
[dev
] = 1;
1724 if (pcm_substreams
[dev
] > MAX_PCM_SUBSTREAMS
)
1725 pcm_substreams
[dev
] = MAX_PCM_SUBSTREAMS
;
1727 loopback
->card
= card
;
1728 loopback_set_timer_source(loopback
, timer_source
[dev
]);
1730 mutex_init(&loopback
->cable_lock
);
1732 err
= loopback_pcm_new(loopback
, 0, pcm_substreams
[dev
]);
1735 err
= loopback_pcm_new(loopback
, 1, pcm_substreams
[dev
]);
1738 err
= loopback_mixer_new(loopback
, pcm_notify
[dev
] ? 1 : 0);
1741 loopback_cable_proc_new(loopback
, 0);
1742 loopback_cable_proc_new(loopback
, 1);
1743 loopback_timer_source_proc_new(loopback
);
1744 strcpy(card
->driver
, "Loopback");
1745 strcpy(card
->shortname
, "Loopback");
1746 sprintf(card
->longname
, "Loopback %i", dev
+ 1);
1747 err
= snd_card_register(card
);
1750 platform_set_drvdata(devptr
, card
);
1754 #ifdef CONFIG_PM_SLEEP
1755 static int loopback_suspend(struct device
*pdev
)
1757 struct snd_card
*card
= dev_get_drvdata(pdev
);
1759 snd_power_change_state(card
, SNDRV_CTL_POWER_D3hot
);
1763 static int loopback_resume(struct device
*pdev
)
1765 struct snd_card
*card
= dev_get_drvdata(pdev
);
1767 snd_power_change_state(card
, SNDRV_CTL_POWER_D0
);
1771 static SIMPLE_DEV_PM_OPS(loopback_pm
, loopback_suspend
, loopback_resume
);
1772 #define LOOPBACK_PM_OPS &loopback_pm
1774 #define LOOPBACK_PM_OPS NULL
1777 #define SND_LOOPBACK_DRIVER "snd_aloop"
1779 static struct platform_driver loopback_driver
= {
1780 .probe
= loopback_probe
,
1782 .name
= SND_LOOPBACK_DRIVER
,
1783 .pm
= LOOPBACK_PM_OPS
,
1787 static void loopback_unregister_all(void)
1791 for (i
= 0; i
< ARRAY_SIZE(devices
); ++i
)
1792 platform_device_unregister(devices
[i
]);
1793 platform_driver_unregister(&loopback_driver
);
1796 static int __init
alsa_card_loopback_init(void)
1800 err
= platform_driver_register(&loopback_driver
);
1806 for (i
= 0; i
< SNDRV_CARDS
; i
++) {
1807 struct platform_device
*device
;
1810 device
= platform_device_register_simple(SND_LOOPBACK_DRIVER
,
1814 if (!platform_get_drvdata(device
)) {
1815 platform_device_unregister(device
);
1818 devices
[i
] = device
;
1823 printk(KERN_ERR
"aloop: No loopback enabled\n");
1825 loopback_unregister_all();
1831 static void __exit
alsa_card_loopback_exit(void)
1833 loopback_unregister_all();
1836 module_init(alsa_card_loopback_init
)
1837 module_exit(alsa_card_loopback_exit
)