5 * Copyright (c) by Jaroslav Kysela <perex@perex.cz>
7 * More accurate positioning and full-duplex support:
8 * Copyright (c) Ahmet İnan <ainan at mathematik.uni-freiburg.de>
10 * Major (almost complete) rewrite:
11 * Copyright (c) by Takashi Iwai <tiwai@suse.de>
13 * A next major update in 2010 (separate timers for playback and capture):
14 * Copyright (c) Jaroslav Kysela <perex@perex.cz>
16 * This program is free software; you can redistribute it and/or modify
17 * it under the terms of the GNU General Public License as published by
18 * the Free Software Foundation; either version 2 of the License, or
19 * (at your option) any later version.
21 * This program is distributed in the hope that it will be useful,
22 * but WITHOUT ANY WARRANTY; without even the implied warranty of
23 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
24 * GNU General Public License for more details.
26 * You should have received a copy of the GNU General Public License
27 * along with this program; if not, write to the Free Software
28 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
32 #include <linux/init.h>
33 #include <linux/jiffies.h>
34 #include <linux/slab.h>
35 #include <linux/time.h>
36 #include <linux/wait.h>
37 #include <linux/moduleparam.h>
38 #include <linux/platform_device.h>
39 #include <sound/core.h>
40 #include <sound/control.h>
41 #include <sound/pcm.h>
42 #include <sound/initval.h>
44 MODULE_AUTHOR("Jaroslav Kysela <perex@perex.cz>");
45 MODULE_DESCRIPTION("A loopback soundcard");
46 MODULE_LICENSE("GPL");
47 MODULE_SUPPORTED_DEVICE("{{ALSA,Loopback soundcard}}");
49 #define MAX_PCM_SUBSTREAMS 8
51 static int index
[SNDRV_CARDS
] = SNDRV_DEFAULT_IDX
; /* Index 0-MAX */
52 static char *id
[SNDRV_CARDS
] = SNDRV_DEFAULT_STR
; /* ID for this card */
53 static int enable
[SNDRV_CARDS
] = {1, [1 ... (SNDRV_CARDS
- 1)] = 0};
54 static int pcm_substreams
[SNDRV_CARDS
] = {[0 ... (SNDRV_CARDS
- 1)] = 8};
55 static int pcm_notify
[SNDRV_CARDS
];
57 module_param_array(index
, int, NULL
, 0444);
58 MODULE_PARM_DESC(index
, "Index value for loopback soundcard.");
59 module_param_array(id
, charp
, NULL
, 0444);
60 MODULE_PARM_DESC(id
, "ID string for loopback soundcard.");
61 module_param_array(enable
, bool, NULL
, 0444);
62 MODULE_PARM_DESC(enable
, "Enable this loopback soundcard.");
63 module_param_array(pcm_substreams
, int, NULL
, 0444);
64 MODULE_PARM_DESC(pcm_substreams
, "PCM substreams # (1-8) for loopback driver.");
65 module_param_array(pcm_notify
, int, NULL
, 0444);
66 MODULE_PARM_DESC(pcm_notify
, "Break capture when PCM format/rate/channels changes.");
68 #define NO_PITCH 100000
72 struct loopback_cable
{
74 struct loopback_pcm
*streams
[2];
75 struct snd_pcm_hardware hw
;
81 struct loopback_setup
{
82 unsigned int notify
: 1;
83 unsigned int rate_shift
;
86 unsigned int channels
;
87 struct snd_ctl_elem_id active_id
;
88 struct snd_ctl_elem_id format_id
;
89 struct snd_ctl_elem_id rate_id
;
90 struct snd_ctl_elem_id channels_id
;
94 struct snd_card
*card
;
95 struct mutex cable_lock
;
96 struct loopback_cable
*cables
[MAX_PCM_SUBSTREAMS
][2];
97 struct snd_pcm
*pcm
[2];
98 struct loopback_setup setup
[MAX_PCM_SUBSTREAMS
][2];
101 struct loopback_pcm
{
102 struct loopback
*loopback
;
103 struct snd_pcm_substream
*substream
;
104 struct loopback_cable
*cable
;
105 unsigned int pcm_buffer_size
;
106 unsigned int buf_pos
; /* position in buffer */
107 unsigned int silent_size
;
109 unsigned int pcm_period_size
;
110 unsigned int pcm_bps
; /* bytes per second */
111 unsigned int pcm_salign
; /* bytes per sample * channels */
112 unsigned int pcm_rate_shift
; /* rate shift value */
114 unsigned int period_update_pending
:1;
116 unsigned int irq_pos
; /* fractional IRQ position */
117 unsigned int period_size_frac
;
118 unsigned long last_jiffies
;
119 struct timer_list timer
;
122 static struct platform_device
*devices
[SNDRV_CARDS
];
124 static inline unsigned int byte_pos(struct loopback_pcm
*dpcm
, unsigned int x
)
126 if (dpcm
->pcm_rate_shift
== NO_PITCH
) {
129 x
= div_u64(NO_PITCH
* (unsigned long long)x
,
130 HZ
* (unsigned long long)dpcm
->pcm_rate_shift
);
132 return x
- (x
% dpcm
->pcm_salign
);
135 static inline unsigned int frac_pos(struct loopback_pcm
*dpcm
, unsigned int x
)
137 if (dpcm
->pcm_rate_shift
== NO_PITCH
) { /* no pitch */
140 x
= div_u64(dpcm
->pcm_rate_shift
* (unsigned long long)x
* HZ
,
146 static inline struct loopback_setup
*get_setup(struct loopback_pcm
*dpcm
)
148 int device
= dpcm
->substream
->pstr
->pcm
->device
;
150 if (dpcm
->substream
->stream
== SNDRV_PCM_STREAM_PLAYBACK
)
152 return &dpcm
->loopback
->setup
[dpcm
->substream
->number
][device
];
155 static inline unsigned int get_notify(struct loopback_pcm
*dpcm
)
157 return get_setup(dpcm
)->notify
;
160 static inline unsigned int get_rate_shift(struct loopback_pcm
*dpcm
)
162 return get_setup(dpcm
)->rate_shift
;
165 static void loopback_timer_start(struct loopback_pcm
*dpcm
)
168 unsigned int rate_shift
= get_rate_shift(dpcm
);
170 if (rate_shift
!= dpcm
->pcm_rate_shift
) {
171 dpcm
->pcm_rate_shift
= rate_shift
;
172 dpcm
->period_size_frac
= frac_pos(dpcm
, dpcm
->pcm_period_size
);
174 tick
= dpcm
->period_size_frac
- dpcm
->irq_pos
;
175 tick
= (tick
+ dpcm
->pcm_bps
- 1) / dpcm
->pcm_bps
;
176 dpcm
->timer
.expires
= jiffies
+ tick
;
177 add_timer(&dpcm
->timer
);
180 static inline void loopback_timer_stop(struct loopback_pcm
*dpcm
)
182 del_timer(&dpcm
->timer
);
185 #define CABLE_VALID_PLAYBACK (1 << SNDRV_PCM_STREAM_PLAYBACK)
186 #define CABLE_VALID_CAPTURE (1 << SNDRV_PCM_STREAM_CAPTURE)
187 #define CABLE_VALID_BOTH (CABLE_VALID_PLAYBACK|CABLE_VALID_CAPTURE)
189 static int loopback_check_format(struct loopback_cable
*cable
, int stream
)
191 struct snd_pcm_runtime
*runtime
, *cruntime
;
192 struct loopback_setup
*setup
;
193 struct snd_card
*card
;
196 if (cable
->valid
!= CABLE_VALID_BOTH
) {
197 if (stream
== SNDRV_PCM_STREAM_PLAYBACK
)
201 runtime
= cable
->streams
[SNDRV_PCM_STREAM_PLAYBACK
]->
203 cruntime
= cable
->streams
[SNDRV_PCM_STREAM_CAPTURE
]->
205 check
= runtime
->format
!= cruntime
->format
||
206 runtime
->rate
!= cruntime
->rate
||
207 runtime
->channels
!= cruntime
->channels
;
210 if (stream
== SNDRV_PCM_STREAM_CAPTURE
) {
213 snd_pcm_stop(cable
->streams
[SNDRV_PCM_STREAM_CAPTURE
]->
214 substream
, SNDRV_PCM_STATE_DRAINING
);
216 runtime
= cable
->streams
[SNDRV_PCM_STREAM_PLAYBACK
]->
218 setup
= get_setup(cable
->streams
[SNDRV_PCM_STREAM_PLAYBACK
]);
219 card
= cable
->streams
[SNDRV_PCM_STREAM_PLAYBACK
]->loopback
->card
;
220 if (setup
->format
!= runtime
->format
) {
221 snd_ctl_notify(card
, SNDRV_CTL_EVENT_MASK_VALUE
,
223 setup
->format
= runtime
->format
;
225 if (setup
->rate
!= runtime
->rate
) {
226 snd_ctl_notify(card
, SNDRV_CTL_EVENT_MASK_VALUE
,
228 setup
->rate
= runtime
->rate
;
230 if (setup
->channels
!= runtime
->channels
) {
231 snd_ctl_notify(card
, SNDRV_CTL_EVENT_MASK_VALUE
,
232 &setup
->channels_id
);
233 setup
->channels
= runtime
->channels
;
239 static void loopback_active_notify(struct loopback_pcm
*dpcm
)
241 snd_ctl_notify(dpcm
->loopback
->card
,
242 SNDRV_CTL_EVENT_MASK_VALUE
,
243 &get_setup(dpcm
)->active_id
);
246 static int loopback_trigger(struct snd_pcm_substream
*substream
, int cmd
)
248 struct snd_pcm_runtime
*runtime
= substream
->runtime
;
249 struct loopback_pcm
*dpcm
= runtime
->private_data
;
250 struct loopback_cable
*cable
= dpcm
->cable
;
254 case SNDRV_PCM_TRIGGER_START
:
255 err
= loopback_check_format(cable
, substream
->stream
);
258 dpcm
->last_jiffies
= jiffies
;
259 dpcm
->pcm_rate_shift
= 0;
260 loopback_timer_start(dpcm
);
261 cable
->running
|= (1 << substream
->stream
);
262 if (substream
->stream
== SNDRV_PCM_STREAM_PLAYBACK
)
263 loopback_active_notify(dpcm
);
265 case SNDRV_PCM_TRIGGER_STOP
:
266 cable
->running
&= ~(1 << substream
->stream
);
267 loopback_timer_stop(dpcm
);
268 if (substream
->stream
== SNDRV_PCM_STREAM_PLAYBACK
)
269 loopback_active_notify(dpcm
);
277 static void params_change_substream(struct loopback_pcm
*dpcm
,
278 struct snd_pcm_runtime
*runtime
)
280 struct snd_pcm_runtime
*dst_runtime
;
282 if (dpcm
== NULL
|| dpcm
->substream
== NULL
)
284 dst_runtime
= dpcm
->substream
->runtime
;
285 if (dst_runtime
== NULL
)
287 dst_runtime
->hw
= dpcm
->cable
->hw
;
290 static void params_change(struct snd_pcm_substream
*substream
)
292 struct snd_pcm_runtime
*runtime
= substream
->runtime
;
293 struct loopback_pcm
*dpcm
= runtime
->private_data
;
294 struct loopback_cable
*cable
= dpcm
->cable
;
296 cable
->hw
.formats
= (1ULL << runtime
->format
);
297 cable
->hw
.rate_min
= runtime
->rate
;
298 cable
->hw
.rate_max
= runtime
->rate
;
299 cable
->hw
.channels_min
= runtime
->channels
;
300 cable
->hw
.channels_max
= runtime
->channels
;
301 params_change_substream(cable
->streams
[SNDRV_PCM_STREAM_PLAYBACK
],
303 params_change_substream(cable
->streams
[SNDRV_PCM_STREAM_CAPTURE
],
307 static int loopback_prepare(struct snd_pcm_substream
*substream
)
309 struct snd_pcm_runtime
*runtime
= substream
->runtime
;
310 struct loopback_pcm
*dpcm
= runtime
->private_data
;
311 struct loopback_cable
*cable
= dpcm
->cable
;
314 salign
= (snd_pcm_format_width(runtime
->format
) *
315 runtime
->channels
) / 8;
316 bps
= salign
* runtime
->rate
;
317 if (bps
<= 0 || salign
<= 0)
321 dpcm
->pcm_buffer_size
= frames_to_bytes(runtime
, runtime
->buffer_size
);
322 if (substream
->stream
== SNDRV_PCM_STREAM_CAPTURE
) {
323 /* clear capture buffer */
324 dpcm
->silent_size
= dpcm
->pcm_buffer_size
;
325 snd_pcm_format_set_silence(runtime
->format
, runtime
->dma_area
,
326 runtime
->buffer_size
* runtime
->channels
);
330 dpcm
->period_update_pending
= 0;
332 dpcm
->pcm_salign
= salign
;
333 dpcm
->pcm_period_size
= frames_to_bytes(runtime
, runtime
->period_size
);
335 mutex_lock(&dpcm
->loopback
->cable_lock
);
336 if (!(cable
->valid
& ~(1 << substream
->stream
)) ||
337 (get_setup(dpcm
)->notify
&&
338 substream
->stream
== SNDRV_PCM_STREAM_PLAYBACK
))
339 params_change(substream
);
340 cable
->valid
|= 1 << substream
->stream
;
341 mutex_unlock(&dpcm
->loopback
->cable_lock
);
346 static void clear_capture_buf(struct loopback_pcm
*dpcm
, unsigned int bytes
)
348 struct snd_pcm_runtime
*runtime
= dpcm
->substream
->runtime
;
349 char *dst
= runtime
->dma_area
;
350 unsigned int dst_off
= dpcm
->buf_pos
;
352 if (dpcm
->silent_size
>= dpcm
->pcm_buffer_size
)
354 if (dpcm
->silent_size
+ bytes
> dpcm
->pcm_buffer_size
)
355 bytes
= dpcm
->pcm_buffer_size
- dpcm
->silent_size
;
358 unsigned int size
= bytes
;
359 if (dst_off
+ size
> dpcm
->pcm_buffer_size
)
360 size
= dpcm
->pcm_buffer_size
- dst_off
;
361 snd_pcm_format_set_silence(runtime
->format
, dst
+ dst_off
,
362 bytes_to_frames(runtime
, size
) *
364 dpcm
->silent_size
+= size
;
372 static void copy_play_buf(struct loopback_pcm
*play
,
373 struct loopback_pcm
*capt
,
376 struct snd_pcm_runtime
*runtime
= play
->substream
->runtime
;
377 char *src
= runtime
->dma_area
;
378 char *dst
= capt
->substream
->runtime
->dma_area
;
379 unsigned int src_off
= play
->buf_pos
;
380 unsigned int dst_off
= capt
->buf_pos
;
381 unsigned int clear_bytes
= 0;
383 /* check if playback is draining, trim the capture copy size
384 * when our pointer is at the end of playback ring buffer */
385 if (runtime
->status
->state
== SNDRV_PCM_STATE_DRAINING
&&
386 snd_pcm_playback_hw_avail(runtime
) < runtime
->buffer_size
) {
387 snd_pcm_uframes_t appl_ptr
, appl_ptr1
, diff
;
388 appl_ptr
= appl_ptr1
= runtime
->control
->appl_ptr
;
389 appl_ptr1
-= appl_ptr1
% runtime
->buffer_size
;
390 appl_ptr1
+= play
->buf_pos
/ play
->pcm_salign
;
391 if (appl_ptr
< appl_ptr1
)
392 appl_ptr1
-= runtime
->buffer_size
;
393 diff
= (appl_ptr
- appl_ptr1
) * play
->pcm_salign
;
395 clear_bytes
= bytes
- diff
;
401 unsigned int size
= bytes
;
402 if (src_off
+ size
> play
->pcm_buffer_size
)
403 size
= play
->pcm_buffer_size
- src_off
;
404 if (dst_off
+ size
> capt
->pcm_buffer_size
)
405 size
= capt
->pcm_buffer_size
- dst_off
;
406 memcpy(dst
+ dst_off
, src
+ src_off
, size
);
407 capt
->silent_size
= 0;
411 src_off
= (src_off
+ size
) % play
->pcm_buffer_size
;
412 dst_off
= (dst_off
+ size
) % capt
->pcm_buffer_size
;
415 if (clear_bytes
> 0) {
416 clear_capture_buf(capt
, clear_bytes
);
417 capt
->silent_size
= 0;
421 #define BYTEPOS_UPDATE_POSONLY 0
422 #define BYTEPOS_UPDATE_CLEAR 1
423 #define BYTEPOS_UPDATE_COPY 2
425 static void loopback_bytepos_update(struct loopback_pcm
*dpcm
,
430 unsigned long last_pos
;
432 last_pos
= byte_pos(dpcm
, dpcm
->irq_pos
);
433 dpcm
->irq_pos
+= delta
* dpcm
->pcm_bps
;
434 count
= byte_pos(dpcm
, dpcm
->irq_pos
) - last_pos
;
437 if (cmd
== BYTEPOS_UPDATE_CLEAR
)
438 clear_capture_buf(dpcm
, count
);
439 else if (cmd
== BYTEPOS_UPDATE_COPY
)
440 copy_play_buf(dpcm
->cable
->streams
[SNDRV_PCM_STREAM_PLAYBACK
],
441 dpcm
->cable
->streams
[SNDRV_PCM_STREAM_CAPTURE
],
443 dpcm
->buf_pos
+= count
;
444 dpcm
->buf_pos
%= dpcm
->pcm_buffer_size
;
445 if (dpcm
->irq_pos
>= dpcm
->period_size_frac
) {
446 dpcm
->irq_pos
%= dpcm
->period_size_frac
;
447 dpcm
->period_update_pending
= 1;
451 static void loopback_pos_update(struct loopback_cable
*cable
)
453 struct loopback_pcm
*dpcm_play
=
454 cable
->streams
[SNDRV_PCM_STREAM_PLAYBACK
];
455 struct loopback_pcm
*dpcm_capt
=
456 cable
->streams
[SNDRV_PCM_STREAM_CAPTURE
];
457 unsigned long delta_play
= 0, delta_capt
= 0;
459 spin_lock(&cable
->lock
);
460 if (cable
->running
& (1 << SNDRV_PCM_STREAM_PLAYBACK
)) {
461 delta_play
= jiffies
- dpcm_play
->last_jiffies
;
462 dpcm_play
->last_jiffies
+= delta_play
;
465 if (cable
->running
& (1 << SNDRV_PCM_STREAM_CAPTURE
)) {
466 delta_capt
= jiffies
- dpcm_capt
->last_jiffies
;
467 dpcm_capt
->last_jiffies
+= delta_capt
;
470 if (delta_play
== 0 && delta_capt
== 0) {
471 spin_unlock(&cable
->lock
);
475 if (delta_play
> delta_capt
) {
476 loopback_bytepos_update(dpcm_play
, delta_play
- delta_capt
,
477 BYTEPOS_UPDATE_POSONLY
);
478 delta_play
= delta_capt
;
479 } else if (delta_play
< delta_capt
) {
480 loopback_bytepos_update(dpcm_capt
, delta_capt
- delta_play
,
481 BYTEPOS_UPDATE_CLEAR
);
482 delta_capt
= delta_play
;
485 if (delta_play
== 0 && delta_capt
== 0) {
486 spin_unlock(&cable
->lock
);
489 /* note delta_capt == delta_play at this moment */
490 loopback_bytepos_update(dpcm_capt
, delta_capt
, BYTEPOS_UPDATE_COPY
);
491 loopback_bytepos_update(dpcm_play
, delta_play
, BYTEPOS_UPDATE_POSONLY
);
492 spin_unlock(&cable
->lock
);
495 static void loopback_timer_function(unsigned long data
)
497 struct loopback_pcm
*dpcm
= (struct loopback_pcm
*)data
;
500 loopback_pos_update(dpcm
->cable
);
501 stream
= dpcm
->substream
->stream
;
502 if (dpcm
->cable
->running
& (1 << stream
))
503 loopback_timer_start(dpcm
);
504 if (dpcm
->period_update_pending
) {
505 dpcm
->period_update_pending
= 0;
506 if (dpcm
->cable
->running
& (1 << stream
))
507 snd_pcm_period_elapsed(dpcm
->substream
);
511 static snd_pcm_uframes_t
loopback_pointer(struct snd_pcm_substream
*substream
)
513 struct snd_pcm_runtime
*runtime
= substream
->runtime
;
514 struct loopback_pcm
*dpcm
= runtime
->private_data
;
516 loopback_pos_update(dpcm
->cable
);
517 return bytes_to_frames(runtime
, dpcm
->buf_pos
);
520 static struct snd_pcm_hardware loopback_pcm_hardware
=
522 .info
= (SNDRV_PCM_INFO_INTERLEAVED
| SNDRV_PCM_INFO_MMAP
|
523 SNDRV_PCM_INFO_MMAP_VALID
),
524 .formats
= (SNDRV_PCM_FMTBIT_S16_LE
| SNDRV_PCM_FMTBIT_S16_BE
|
525 SNDRV_PCM_FMTBIT_S32_LE
| SNDRV_PCM_FMTBIT_S32_BE
|
526 SNDRV_PCM_FMTBIT_FLOAT_LE
| SNDRV_PCM_FMTBIT_FLOAT_BE
),
527 .rates
= SNDRV_PCM_RATE_CONTINUOUS
| SNDRV_PCM_RATE_8000_192000
,
532 .buffer_bytes_max
= 2 * 1024 * 1024,
533 .period_bytes_min
= 64,
534 .period_bytes_max
= 2 * 1024 * 1024,
540 static void loopback_runtime_free(struct snd_pcm_runtime
*runtime
)
542 struct loopback_pcm
*dpcm
= runtime
->private_data
;
546 static int loopback_hw_params(struct snd_pcm_substream
*substream
,
547 struct snd_pcm_hw_params
*params
)
549 return snd_pcm_lib_malloc_pages(substream
, params_buffer_bytes(params
));
552 static int loopback_hw_free(struct snd_pcm_substream
*substream
)
554 struct snd_pcm_runtime
*runtime
= substream
->runtime
;
555 struct loopback_pcm
*dpcm
= runtime
->private_data
;
556 struct loopback_cable
*cable
= dpcm
->cable
;
558 mutex_lock(&dpcm
->loopback
->cable_lock
);
559 cable
->valid
&= ~(1 << substream
->stream
);
560 mutex_unlock(&dpcm
->loopback
->cable_lock
);
561 return snd_pcm_lib_free_pages(substream
);
564 static unsigned int get_cable_index(struct snd_pcm_substream
*substream
)
566 if (!substream
->pcm
->device
)
567 return substream
->stream
;
569 return !substream
->stream
;
572 static int rule_format(struct snd_pcm_hw_params
*params
,
573 struct snd_pcm_hw_rule
*rule
)
576 struct snd_pcm_hardware
*hw
= rule
->private;
577 struct snd_mask
*maskp
= hw_param_mask(params
, rule
->var
);
579 maskp
->bits
[0] &= (u_int32_t
)hw
->formats
;
580 maskp
->bits
[1] &= (u_int32_t
)(hw
->formats
>> 32);
581 memset(maskp
->bits
+ 2, 0, (SNDRV_MASK_MAX
-64) / 8); /* clear rest */
582 if (! maskp
->bits
[0] && ! maskp
->bits
[1])
587 static int rule_rate(struct snd_pcm_hw_params
*params
,
588 struct snd_pcm_hw_rule
*rule
)
590 struct snd_pcm_hardware
*hw
= rule
->private;
591 struct snd_interval t
;
593 t
.min
= hw
->rate_min
;
594 t
.max
= hw
->rate_max
;
595 t
.openmin
= t
.openmax
= 0;
597 return snd_interval_refine(hw_param_interval(params
, rule
->var
), &t
);
600 static int rule_channels(struct snd_pcm_hw_params
*params
,
601 struct snd_pcm_hw_rule
*rule
)
603 struct snd_pcm_hardware
*hw
= rule
->private;
604 struct snd_interval t
;
606 t
.min
= hw
->channels_min
;
607 t
.max
= hw
->channels_max
;
608 t
.openmin
= t
.openmax
= 0;
610 return snd_interval_refine(hw_param_interval(params
, rule
->var
), &t
);
613 static int loopback_open(struct snd_pcm_substream
*substream
)
615 struct snd_pcm_runtime
*runtime
= substream
->runtime
;
616 struct loopback
*loopback
= substream
->private_data
;
617 struct loopback_pcm
*dpcm
;
618 struct loopback_cable
*cable
;
620 int dev
= get_cable_index(substream
);
622 mutex_lock(&loopback
->cable_lock
);
623 dpcm
= kzalloc(sizeof(*dpcm
), GFP_KERNEL
);
628 dpcm
->loopback
= loopback
;
629 dpcm
->substream
= substream
;
630 setup_timer(&dpcm
->timer
, loopback_timer_function
,
631 (unsigned long)dpcm
);
633 cable
= loopback
->cables
[substream
->number
][dev
];
635 cable
= kzalloc(sizeof(*cable
), GFP_KERNEL
);
641 spin_lock_init(&cable
->lock
);
642 cable
->hw
= loopback_pcm_hardware
;
643 loopback
->cables
[substream
->number
][dev
] = cable
;
646 cable
->streams
[substream
->stream
] = dpcm
;
648 snd_pcm_hw_constraint_integer(runtime
, SNDRV_PCM_HW_PARAM_PERIODS
);
650 /* use dynamic rules based on actual runtime->hw values */
651 /* note that the default rules created in the PCM midlevel code */
652 /* are cached -> they do not reflect the actual state */
653 err
= snd_pcm_hw_rule_add(runtime
, 0,
654 SNDRV_PCM_HW_PARAM_FORMAT
,
655 rule_format
, &runtime
->hw
,
656 SNDRV_PCM_HW_PARAM_FORMAT
, -1);
659 err
= snd_pcm_hw_rule_add(runtime
, 0,
660 SNDRV_PCM_HW_PARAM_RATE
,
661 rule_rate
, &runtime
->hw
,
662 SNDRV_PCM_HW_PARAM_RATE
, -1);
665 err
= snd_pcm_hw_rule_add(runtime
, 0,
666 SNDRV_PCM_HW_PARAM_CHANNELS
,
667 rule_channels
, &runtime
->hw
,
668 SNDRV_PCM_HW_PARAM_CHANNELS
, -1);
672 runtime
->private_data
= dpcm
;
673 runtime
->private_free
= loopback_runtime_free
;
674 if (get_notify(dpcm
))
675 runtime
->hw
= loopback_pcm_hardware
;
677 runtime
->hw
= cable
->hw
;
679 mutex_unlock(&loopback
->cable_lock
);
683 static int loopback_close(struct snd_pcm_substream
*substream
)
685 struct loopback
*loopback
= substream
->private_data
;
686 struct loopback_pcm
*dpcm
= substream
->runtime
->private_data
;
687 struct loopback_cable
*cable
;
688 int dev
= get_cable_index(substream
);
690 loopback_timer_stop(dpcm
);
691 mutex_lock(&loopback
->cable_lock
);
692 cable
= loopback
->cables
[substream
->number
][dev
];
693 if (cable
->streams
[!substream
->stream
]) {
694 /* other stream is still alive */
695 cable
->streams
[substream
->stream
] = NULL
;
698 loopback
->cables
[substream
->number
][dev
] = NULL
;
701 mutex_unlock(&loopback
->cable_lock
);
705 static struct snd_pcm_ops loopback_playback_ops
= {
706 .open
= loopback_open
,
707 .close
= loopback_close
,
708 .ioctl
= snd_pcm_lib_ioctl
,
709 .hw_params
= loopback_hw_params
,
710 .hw_free
= loopback_hw_free
,
711 .prepare
= loopback_prepare
,
712 .trigger
= loopback_trigger
,
713 .pointer
= loopback_pointer
,
716 static struct snd_pcm_ops loopback_capture_ops
= {
717 .open
= loopback_open
,
718 .close
= loopback_close
,
719 .ioctl
= snd_pcm_lib_ioctl
,
720 .hw_params
= loopback_hw_params
,
721 .hw_free
= loopback_hw_free
,
722 .prepare
= loopback_prepare
,
723 .trigger
= loopback_trigger
,
724 .pointer
= loopback_pointer
,
727 static int __devinit
loopback_pcm_new(struct loopback
*loopback
,
728 int device
, int substreams
)
733 err
= snd_pcm_new(loopback
->card
, "Loopback PCM", device
,
734 substreams
, substreams
, &pcm
);
737 snd_pcm_set_ops(pcm
, SNDRV_PCM_STREAM_PLAYBACK
, &loopback_playback_ops
);
738 snd_pcm_set_ops(pcm
, SNDRV_PCM_STREAM_CAPTURE
, &loopback_capture_ops
);
740 pcm
->private_data
= loopback
;
742 strcpy(pcm
->name
, "Loopback PCM");
744 loopback
->pcm
[device
] = pcm
;
746 snd_pcm_lib_preallocate_pages_for_all(pcm
, SNDRV_DMA_TYPE_CONTINUOUS
,
747 snd_dma_continuous_data(GFP_KERNEL
),
752 static int loopback_rate_shift_info(struct snd_kcontrol
*kcontrol
,
753 struct snd_ctl_elem_info
*uinfo
)
755 uinfo
->type
= SNDRV_CTL_ELEM_TYPE_INTEGER
;
757 uinfo
->value
.integer
.min
= 80000;
758 uinfo
->value
.integer
.max
= 120000;
759 uinfo
->value
.integer
.step
= 1;
763 static int loopback_rate_shift_get(struct snd_kcontrol
*kcontrol
,
764 struct snd_ctl_elem_value
*ucontrol
)
766 struct loopback
*loopback
= snd_kcontrol_chip(kcontrol
);
768 ucontrol
->value
.integer
.value
[0] =
769 loopback
->setup
[kcontrol
->id
.subdevice
]
770 [kcontrol
->id
.device
].rate_shift
;
774 static int loopback_rate_shift_put(struct snd_kcontrol
*kcontrol
,
775 struct snd_ctl_elem_value
*ucontrol
)
777 struct loopback
*loopback
= snd_kcontrol_chip(kcontrol
);
781 val
= ucontrol
->value
.integer
.value
[0];
786 mutex_lock(&loopback
->cable_lock
);
787 if (val
!= loopback
->setup
[kcontrol
->id
.subdevice
]
788 [kcontrol
->id
.device
].rate_shift
) {
789 loopback
->setup
[kcontrol
->id
.subdevice
]
790 [kcontrol
->id
.device
].rate_shift
= val
;
793 mutex_unlock(&loopback
->cable_lock
);
797 static int loopback_notify_get(struct snd_kcontrol
*kcontrol
,
798 struct snd_ctl_elem_value
*ucontrol
)
800 struct loopback
*loopback
= snd_kcontrol_chip(kcontrol
);
802 ucontrol
->value
.integer
.value
[0] =
803 loopback
->setup
[kcontrol
->id
.subdevice
]
804 [kcontrol
->id
.device
].notify
;
808 static int loopback_notify_put(struct snd_kcontrol
*kcontrol
,
809 struct snd_ctl_elem_value
*ucontrol
)
811 struct loopback
*loopback
= snd_kcontrol_chip(kcontrol
);
815 val
= ucontrol
->value
.integer
.value
[0] ? 1 : 0;
816 if (val
!= loopback
->setup
[kcontrol
->id
.subdevice
]
817 [kcontrol
->id
.device
].notify
) {
818 loopback
->setup
[kcontrol
->id
.subdevice
]
819 [kcontrol
->id
.device
].notify
= val
;
825 static int loopback_active_get(struct snd_kcontrol
*kcontrol
,
826 struct snd_ctl_elem_value
*ucontrol
)
828 struct loopback
*loopback
= snd_kcontrol_chip(kcontrol
);
829 struct loopback_cable
*cable
= loopback
->cables
830 [kcontrol
->id
.subdevice
][kcontrol
->id
.device
^ 1];
831 unsigned int val
= 0;
834 val
= (cable
->running
& (1 << SNDRV_PCM_STREAM_PLAYBACK
)) ?
836 ucontrol
->value
.integer
.value
[0] = val
;
840 static int loopback_format_info(struct snd_kcontrol
*kcontrol
,
841 struct snd_ctl_elem_info
*uinfo
)
843 uinfo
->type
= SNDRV_CTL_ELEM_TYPE_INTEGER
;
845 uinfo
->value
.integer
.min
= 0;
846 uinfo
->value
.integer
.max
= SNDRV_PCM_FORMAT_LAST
;
847 uinfo
->value
.integer
.step
= 1;
851 static int loopback_format_get(struct snd_kcontrol
*kcontrol
,
852 struct snd_ctl_elem_value
*ucontrol
)
854 struct loopback
*loopback
= snd_kcontrol_chip(kcontrol
);
856 ucontrol
->value
.integer
.value
[0] =
857 loopback
->setup
[kcontrol
->id
.subdevice
]
858 [kcontrol
->id
.device
].format
;
862 static int loopback_rate_info(struct snd_kcontrol
*kcontrol
,
863 struct snd_ctl_elem_info
*uinfo
)
865 uinfo
->type
= SNDRV_CTL_ELEM_TYPE_INTEGER
;
867 uinfo
->value
.integer
.min
= 0;
868 uinfo
->value
.integer
.max
= 192000;
869 uinfo
->value
.integer
.step
= 1;
873 static int loopback_rate_get(struct snd_kcontrol
*kcontrol
,
874 struct snd_ctl_elem_value
*ucontrol
)
876 struct loopback
*loopback
= snd_kcontrol_chip(kcontrol
);
878 ucontrol
->value
.integer
.value
[0] =
879 loopback
->setup
[kcontrol
->id
.subdevice
]
880 [kcontrol
->id
.device
].rate
;
884 static int loopback_channels_info(struct snd_kcontrol
*kcontrol
,
885 struct snd_ctl_elem_info
*uinfo
)
887 uinfo
->type
= SNDRV_CTL_ELEM_TYPE_INTEGER
;
889 uinfo
->value
.integer
.min
= 1;
890 uinfo
->value
.integer
.max
= 1024;
891 uinfo
->value
.integer
.step
= 1;
895 static int loopback_channels_get(struct snd_kcontrol
*kcontrol
,
896 struct snd_ctl_elem_value
*ucontrol
)
898 struct loopback
*loopback
= snd_kcontrol_chip(kcontrol
);
900 ucontrol
->value
.integer
.value
[0] =
901 loopback
->setup
[kcontrol
->id
.subdevice
]
902 [kcontrol
->id
.device
].channels
;
906 static struct snd_kcontrol_new loopback_controls
[] __devinitdata
= {
908 .iface
= SNDRV_CTL_ELEM_IFACE_PCM
,
909 .name
= "PCM Rate Shift 100000",
910 .info
= loopback_rate_shift_info
,
911 .get
= loopback_rate_shift_get
,
912 .put
= loopback_rate_shift_put
,
915 .iface
= SNDRV_CTL_ELEM_IFACE_PCM
,
916 .name
= "PCM Notify",
917 .info
= snd_ctl_boolean_mono_info
,
918 .get
= loopback_notify_get
,
919 .put
= loopback_notify_put
,
923 .access
= SNDRV_CTL_ELEM_ACCESS_READ
,
924 .iface
= SNDRV_CTL_ELEM_IFACE_PCM
,
925 .name
= "PCM Slave Active",
926 .info
= snd_ctl_boolean_mono_info
,
927 .get
= loopback_active_get
,
931 .access
= SNDRV_CTL_ELEM_ACCESS_READ
,
932 .iface
= SNDRV_CTL_ELEM_IFACE_PCM
,
933 .name
= "PCM Slave Format",
934 .info
= loopback_format_info
,
935 .get
= loopback_format_get
939 .access
= SNDRV_CTL_ELEM_ACCESS_READ
,
940 .iface
= SNDRV_CTL_ELEM_IFACE_PCM
,
941 .name
= "PCM Slave Rate",
942 .info
= loopback_rate_info
,
943 .get
= loopback_rate_get
945 #define CHANNELS_IDX 5
947 .access
= SNDRV_CTL_ELEM_ACCESS_READ
,
948 .iface
= SNDRV_CTL_ELEM_IFACE_PCM
,
949 .name
= "PCM Slave Channels",
950 .info
= loopback_channels_info
,
951 .get
= loopback_channels_get
955 static int __devinit
loopback_mixer_new(struct loopback
*loopback
, int notify
)
957 struct snd_card
*card
= loopback
->card
;
959 struct snd_kcontrol
*kctl
;
960 struct loopback_setup
*setup
;
961 int err
, dev
, substr
, substr_count
, idx
;
963 strcpy(card
->mixername
, "Loopback Mixer");
964 for (dev
= 0; dev
< 2; dev
++) {
965 pcm
= loopback
->pcm
[dev
];
967 pcm
->streams
[SNDRV_PCM_STREAM_CAPTURE
].substream_count
;
968 for (substr
= 0; substr
< substr_count
; substr
++) {
969 setup
= &loopback
->setup
[substr
][dev
];
970 setup
->notify
= notify
;
971 setup
->rate_shift
= NO_PITCH
;
972 setup
->format
= SNDRV_PCM_FORMAT_S16_LE
;
975 for (idx
= 0; idx
< ARRAY_SIZE(loopback_controls
);
977 kctl
= snd_ctl_new1(&loopback_controls
[idx
],
981 kctl
->id
.device
= dev
;
982 kctl
->id
.subdevice
= substr
;
985 setup
->active_id
= kctl
->id
;
988 setup
->format_id
= kctl
->id
;
991 setup
->rate_id
= kctl
->id
;
994 setup
->channels_id
= kctl
->id
;
999 err
= snd_ctl_add(card
, kctl
);
1008 static int __devinit
loopback_probe(struct platform_device
*devptr
)
1010 struct snd_card
*card
;
1011 struct loopback
*loopback
;
1012 int dev
= devptr
->id
;
1015 err
= snd_card_create(index
[dev
], id
[dev
], THIS_MODULE
,
1016 sizeof(struct loopback
), &card
);
1019 loopback
= card
->private_data
;
1021 if (pcm_substreams
[dev
] < 1)
1022 pcm_substreams
[dev
] = 1;
1023 if (pcm_substreams
[dev
] > MAX_PCM_SUBSTREAMS
)
1024 pcm_substreams
[dev
] = MAX_PCM_SUBSTREAMS
;
1026 loopback
->card
= card
;
1027 mutex_init(&loopback
->cable_lock
);
1029 err
= loopback_pcm_new(loopback
, 0, pcm_substreams
[dev
]);
1032 err
= loopback_pcm_new(loopback
, 1, pcm_substreams
[dev
]);
1035 err
= loopback_mixer_new(loopback
, pcm_notify
[dev
] ? 1 : 0);
1038 strcpy(card
->driver
, "Loopback");
1039 strcpy(card
->shortname
, "Loopback");
1040 sprintf(card
->longname
, "Loopback %i", dev
+ 1);
1041 err
= snd_card_register(card
);
1043 platform_set_drvdata(devptr
, card
);
1047 snd_card_free(card
);
1051 static int __devexit
loopback_remove(struct platform_device
*devptr
)
1053 snd_card_free(platform_get_drvdata(devptr
));
1054 platform_set_drvdata(devptr
, NULL
);
1059 static int loopback_suspend(struct platform_device
*pdev
,
1062 struct snd_card
*card
= platform_get_drvdata(pdev
);
1063 struct loopback
*loopback
= card
->private_data
;
1065 snd_power_change_state(card
, SNDRV_CTL_POWER_D3hot
);
1067 snd_pcm_suspend_all(loopback
->pcm
[0]);
1068 snd_pcm_suspend_all(loopback
->pcm
[1]);
1072 static int loopback_resume(struct platform_device
*pdev
)
1074 struct snd_card
*card
= platform_get_drvdata(pdev
);
1076 snd_power_change_state(card
, SNDRV_CTL_POWER_D0
);
1081 #define SND_LOOPBACK_DRIVER "snd_aloop"
1083 static struct platform_driver loopback_driver
= {
1084 .probe
= loopback_probe
,
1085 .remove
= __devexit_p(loopback_remove
),
1087 .suspend
= loopback_suspend
,
1088 .resume
= loopback_resume
,
1091 .name
= SND_LOOPBACK_DRIVER
1095 static void loopback_unregister_all(void)
1099 for (i
= 0; i
< ARRAY_SIZE(devices
); ++i
)
1100 platform_device_unregister(devices
[i
]);
1101 platform_driver_unregister(&loopback_driver
);
1104 static int __init
alsa_card_loopback_init(void)
1108 err
= platform_driver_register(&loopback_driver
);
1114 for (i
= 0; i
< SNDRV_CARDS
; i
++) {
1115 struct platform_device
*device
;
1118 device
= platform_device_register_simple(SND_LOOPBACK_DRIVER
,
1122 if (!platform_get_drvdata(device
)) {
1123 platform_device_unregister(device
);
1126 devices
[i
] = device
;
1131 printk(KERN_ERR
"aloop: No loopback enabled\n");
1133 loopback_unregister_all();
1139 static void __exit
alsa_card_loopback_exit(void)
1141 loopback_unregister_all();
1144 module_init(alsa_card_loopback_init
)
1145 module_exit(alsa_card_loopback_exit
)