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/info.h>
43 #include <sound/initval.h>
45 MODULE_AUTHOR("Jaroslav Kysela <perex@perex.cz>");
46 MODULE_DESCRIPTION("A loopback soundcard");
47 MODULE_LICENSE("GPL");
48 MODULE_SUPPORTED_DEVICE("{{ALSA,Loopback soundcard}}");
50 #define MAX_PCM_SUBSTREAMS 8
52 static int index
[SNDRV_CARDS
] = SNDRV_DEFAULT_IDX
; /* Index 0-MAX */
53 static char *id
[SNDRV_CARDS
] = SNDRV_DEFAULT_STR
; /* ID for this card */
54 static int enable
[SNDRV_CARDS
] = {1, [1 ... (SNDRV_CARDS
- 1)] = 0};
55 static int pcm_substreams
[SNDRV_CARDS
] = {[0 ... (SNDRV_CARDS
- 1)] = 8};
56 static int pcm_notify
[SNDRV_CARDS
];
58 module_param_array(index
, int, NULL
, 0444);
59 MODULE_PARM_DESC(index
, "Index value for loopback soundcard.");
60 module_param_array(id
, charp
, NULL
, 0444);
61 MODULE_PARM_DESC(id
, "ID string for loopback soundcard.");
62 module_param_array(enable
, bool, NULL
, 0444);
63 MODULE_PARM_DESC(enable
, "Enable this loopback soundcard.");
64 module_param_array(pcm_substreams
, int, NULL
, 0444);
65 MODULE_PARM_DESC(pcm_substreams
, "PCM substreams # (1-8) for loopback driver.");
66 module_param_array(pcm_notify
, int, NULL
, 0444);
67 MODULE_PARM_DESC(pcm_notify
, "Break capture when PCM format/rate/channels changes.");
69 #define NO_PITCH 100000
73 struct loopback_cable
{
75 struct loopback_pcm
*streams
[2];
76 struct snd_pcm_hardware hw
;
82 struct loopback_setup
{
83 unsigned int notify
: 1;
84 unsigned int rate_shift
;
87 unsigned int channels
;
88 struct snd_ctl_elem_id active_id
;
89 struct snd_ctl_elem_id format_id
;
90 struct snd_ctl_elem_id rate_id
;
91 struct snd_ctl_elem_id channels_id
;
95 struct snd_card
*card
;
96 struct mutex cable_lock
;
97 struct loopback_cable
*cables
[MAX_PCM_SUBSTREAMS
][2];
98 struct snd_pcm
*pcm
[2];
99 struct loopback_setup setup
[MAX_PCM_SUBSTREAMS
][2];
102 struct loopback_pcm
{
103 struct loopback
*loopback
;
104 struct snd_pcm_substream
*substream
;
105 struct loopback_cable
*cable
;
106 unsigned int pcm_buffer_size
;
107 unsigned int buf_pos
; /* position in buffer */
108 unsigned int silent_size
;
110 unsigned int pcm_period_size
;
111 unsigned int pcm_bps
; /* bytes per second */
112 unsigned int pcm_salign
; /* bytes per sample * channels */
113 unsigned int pcm_rate_shift
; /* rate shift value */
115 unsigned int period_update_pending
:1;
117 unsigned int irq_pos
; /* fractional IRQ position */
118 unsigned int period_size_frac
;
119 unsigned long last_jiffies
;
120 struct timer_list timer
;
123 static struct platform_device
*devices
[SNDRV_CARDS
];
125 static inline unsigned int byte_pos(struct loopback_pcm
*dpcm
, unsigned int x
)
127 if (dpcm
->pcm_rate_shift
== NO_PITCH
) {
130 x
= div_u64(NO_PITCH
* (unsigned long long)x
,
131 HZ
* (unsigned long long)dpcm
->pcm_rate_shift
);
133 return x
- (x
% dpcm
->pcm_salign
);
136 static inline unsigned int frac_pos(struct loopback_pcm
*dpcm
, unsigned int x
)
138 if (dpcm
->pcm_rate_shift
== NO_PITCH
) { /* no pitch */
141 x
= div_u64(dpcm
->pcm_rate_shift
* (unsigned long long)x
* HZ
,
147 static inline struct loopback_setup
*get_setup(struct loopback_pcm
*dpcm
)
149 int device
= dpcm
->substream
->pstr
->pcm
->device
;
151 if (dpcm
->substream
->stream
== SNDRV_PCM_STREAM_PLAYBACK
)
153 return &dpcm
->loopback
->setup
[dpcm
->substream
->number
][device
];
156 static inline unsigned int get_notify(struct loopback_pcm
*dpcm
)
158 return get_setup(dpcm
)->notify
;
161 static inline unsigned int get_rate_shift(struct loopback_pcm
*dpcm
)
163 return get_setup(dpcm
)->rate_shift
;
166 static void loopback_timer_start(struct loopback_pcm
*dpcm
)
169 unsigned int rate_shift
= get_rate_shift(dpcm
);
171 if (rate_shift
!= dpcm
->pcm_rate_shift
) {
172 dpcm
->pcm_rate_shift
= rate_shift
;
173 dpcm
->period_size_frac
= frac_pos(dpcm
, dpcm
->pcm_period_size
);
175 if (dpcm
->period_size_frac
<= dpcm
->irq_pos
) {
176 dpcm
->irq_pos
%= dpcm
->period_size_frac
;
177 dpcm
->period_update_pending
= 1;
179 tick
= dpcm
->period_size_frac
- dpcm
->irq_pos
;
180 tick
= (tick
+ dpcm
->pcm_bps
- 1) / dpcm
->pcm_bps
;
181 dpcm
->timer
.expires
= jiffies
+ tick
;
182 add_timer(&dpcm
->timer
);
185 static inline void loopback_timer_stop(struct loopback_pcm
*dpcm
)
187 del_timer(&dpcm
->timer
);
188 dpcm
->timer
.expires
= 0;
191 #define CABLE_VALID_PLAYBACK (1 << SNDRV_PCM_STREAM_PLAYBACK)
192 #define CABLE_VALID_CAPTURE (1 << SNDRV_PCM_STREAM_CAPTURE)
193 #define CABLE_VALID_BOTH (CABLE_VALID_PLAYBACK|CABLE_VALID_CAPTURE)
195 static int loopback_check_format(struct loopback_cable
*cable
, int stream
)
197 struct snd_pcm_runtime
*runtime
, *cruntime
;
198 struct loopback_setup
*setup
;
199 struct snd_card
*card
;
202 if (cable
->valid
!= CABLE_VALID_BOTH
) {
203 if (stream
== SNDRV_PCM_STREAM_PLAYBACK
)
207 runtime
= cable
->streams
[SNDRV_PCM_STREAM_PLAYBACK
]->
209 cruntime
= cable
->streams
[SNDRV_PCM_STREAM_CAPTURE
]->
211 check
= runtime
->format
!= cruntime
->format
||
212 runtime
->rate
!= cruntime
->rate
||
213 runtime
->channels
!= cruntime
->channels
;
216 if (stream
== SNDRV_PCM_STREAM_CAPTURE
) {
219 snd_pcm_stop(cable
->streams
[SNDRV_PCM_STREAM_CAPTURE
]->
220 substream
, SNDRV_PCM_STATE_DRAINING
);
222 runtime
= cable
->streams
[SNDRV_PCM_STREAM_PLAYBACK
]->
224 setup
= get_setup(cable
->streams
[SNDRV_PCM_STREAM_PLAYBACK
]);
225 card
= cable
->streams
[SNDRV_PCM_STREAM_PLAYBACK
]->loopback
->card
;
226 if (setup
->format
!= runtime
->format
) {
227 snd_ctl_notify(card
, SNDRV_CTL_EVENT_MASK_VALUE
,
229 setup
->format
= runtime
->format
;
231 if (setup
->rate
!= runtime
->rate
) {
232 snd_ctl_notify(card
, SNDRV_CTL_EVENT_MASK_VALUE
,
234 setup
->rate
= runtime
->rate
;
236 if (setup
->channels
!= runtime
->channels
) {
237 snd_ctl_notify(card
, SNDRV_CTL_EVENT_MASK_VALUE
,
238 &setup
->channels_id
);
239 setup
->channels
= runtime
->channels
;
245 static void loopback_active_notify(struct loopback_pcm
*dpcm
)
247 snd_ctl_notify(dpcm
->loopback
->card
,
248 SNDRV_CTL_EVENT_MASK_VALUE
,
249 &get_setup(dpcm
)->active_id
);
252 static int loopback_trigger(struct snd_pcm_substream
*substream
, int cmd
)
254 struct snd_pcm_runtime
*runtime
= substream
->runtime
;
255 struct loopback_pcm
*dpcm
= runtime
->private_data
;
256 struct loopback_cable
*cable
= dpcm
->cable
;
260 case SNDRV_PCM_TRIGGER_START
:
261 err
= loopback_check_format(cable
, substream
->stream
);
264 dpcm
->last_jiffies
= jiffies
;
265 dpcm
->pcm_rate_shift
= 0;
266 loopback_timer_start(dpcm
);
267 cable
->running
|= (1 << substream
->stream
);
268 if (substream
->stream
== SNDRV_PCM_STREAM_PLAYBACK
)
269 loopback_active_notify(dpcm
);
271 case SNDRV_PCM_TRIGGER_STOP
:
272 cable
->running
&= ~(1 << substream
->stream
);
273 loopback_timer_stop(dpcm
);
274 if (substream
->stream
== SNDRV_PCM_STREAM_PLAYBACK
)
275 loopback_active_notify(dpcm
);
283 static void params_change_substream(struct loopback_pcm
*dpcm
,
284 struct snd_pcm_runtime
*runtime
)
286 struct snd_pcm_runtime
*dst_runtime
;
288 if (dpcm
== NULL
|| dpcm
->substream
== NULL
)
290 dst_runtime
= dpcm
->substream
->runtime
;
291 if (dst_runtime
== NULL
)
293 dst_runtime
->hw
= dpcm
->cable
->hw
;
296 static void params_change(struct snd_pcm_substream
*substream
)
298 struct snd_pcm_runtime
*runtime
= substream
->runtime
;
299 struct loopback_pcm
*dpcm
= runtime
->private_data
;
300 struct loopback_cable
*cable
= dpcm
->cable
;
302 cable
->hw
.formats
= (1ULL << runtime
->format
);
303 cable
->hw
.rate_min
= runtime
->rate
;
304 cable
->hw
.rate_max
= runtime
->rate
;
305 cable
->hw
.channels_min
= runtime
->channels
;
306 cable
->hw
.channels_max
= runtime
->channels
;
307 params_change_substream(cable
->streams
[SNDRV_PCM_STREAM_PLAYBACK
],
309 params_change_substream(cable
->streams
[SNDRV_PCM_STREAM_CAPTURE
],
313 static int loopback_prepare(struct snd_pcm_substream
*substream
)
315 struct snd_pcm_runtime
*runtime
= substream
->runtime
;
316 struct loopback_pcm
*dpcm
= runtime
->private_data
;
317 struct loopback_cable
*cable
= dpcm
->cable
;
320 salign
= (snd_pcm_format_width(runtime
->format
) *
321 runtime
->channels
) / 8;
322 bps
= salign
* runtime
->rate
;
323 if (bps
<= 0 || salign
<= 0)
327 dpcm
->pcm_buffer_size
= frames_to_bytes(runtime
, runtime
->buffer_size
);
328 if (substream
->stream
== SNDRV_PCM_STREAM_CAPTURE
) {
329 /* clear capture buffer */
330 dpcm
->silent_size
= dpcm
->pcm_buffer_size
;
331 snd_pcm_format_set_silence(runtime
->format
, runtime
->dma_area
,
332 runtime
->buffer_size
* runtime
->channels
);
336 dpcm
->period_update_pending
= 0;
338 dpcm
->pcm_salign
= salign
;
339 dpcm
->pcm_period_size
= frames_to_bytes(runtime
, runtime
->period_size
);
341 mutex_lock(&dpcm
->loopback
->cable_lock
);
342 if (!(cable
->valid
& ~(1 << substream
->stream
)) ||
343 (get_setup(dpcm
)->notify
&&
344 substream
->stream
== SNDRV_PCM_STREAM_PLAYBACK
))
345 params_change(substream
);
346 cable
->valid
|= 1 << substream
->stream
;
347 mutex_unlock(&dpcm
->loopback
->cable_lock
);
352 static void clear_capture_buf(struct loopback_pcm
*dpcm
, unsigned int bytes
)
354 struct snd_pcm_runtime
*runtime
= dpcm
->substream
->runtime
;
355 char *dst
= runtime
->dma_area
;
356 unsigned int dst_off
= dpcm
->buf_pos
;
358 if (dpcm
->silent_size
>= dpcm
->pcm_buffer_size
)
360 if (dpcm
->silent_size
+ bytes
> dpcm
->pcm_buffer_size
)
361 bytes
= dpcm
->pcm_buffer_size
- dpcm
->silent_size
;
364 unsigned int size
= bytes
;
365 if (dst_off
+ size
> dpcm
->pcm_buffer_size
)
366 size
= dpcm
->pcm_buffer_size
- dst_off
;
367 snd_pcm_format_set_silence(runtime
->format
, dst
+ dst_off
,
368 bytes_to_frames(runtime
, size
) *
370 dpcm
->silent_size
+= size
;
378 static void copy_play_buf(struct loopback_pcm
*play
,
379 struct loopback_pcm
*capt
,
382 struct snd_pcm_runtime
*runtime
= play
->substream
->runtime
;
383 char *src
= runtime
->dma_area
;
384 char *dst
= capt
->substream
->runtime
->dma_area
;
385 unsigned int src_off
= play
->buf_pos
;
386 unsigned int dst_off
= capt
->buf_pos
;
387 unsigned int clear_bytes
= 0;
389 /* check if playback is draining, trim the capture copy size
390 * when our pointer is at the end of playback ring buffer */
391 if (runtime
->status
->state
== SNDRV_PCM_STATE_DRAINING
&&
392 snd_pcm_playback_hw_avail(runtime
) < runtime
->buffer_size
) {
393 snd_pcm_uframes_t appl_ptr
, appl_ptr1
, diff
;
394 appl_ptr
= appl_ptr1
= runtime
->control
->appl_ptr
;
395 appl_ptr1
-= appl_ptr1
% runtime
->buffer_size
;
396 appl_ptr1
+= play
->buf_pos
/ play
->pcm_salign
;
397 if (appl_ptr
< appl_ptr1
)
398 appl_ptr1
-= runtime
->buffer_size
;
399 diff
= (appl_ptr
- appl_ptr1
) * play
->pcm_salign
;
401 clear_bytes
= bytes
- diff
;
407 unsigned int size
= bytes
;
408 if (src_off
+ size
> play
->pcm_buffer_size
)
409 size
= play
->pcm_buffer_size
- src_off
;
410 if (dst_off
+ size
> capt
->pcm_buffer_size
)
411 size
= capt
->pcm_buffer_size
- dst_off
;
412 memcpy(dst
+ dst_off
, src
+ src_off
, size
);
413 capt
->silent_size
= 0;
417 src_off
= (src_off
+ size
) % play
->pcm_buffer_size
;
418 dst_off
= (dst_off
+ size
) % capt
->pcm_buffer_size
;
421 if (clear_bytes
> 0) {
422 clear_capture_buf(capt
, clear_bytes
);
423 capt
->silent_size
= 0;
427 #define BYTEPOS_UPDATE_POSONLY 0
428 #define BYTEPOS_UPDATE_CLEAR 1
429 #define BYTEPOS_UPDATE_COPY 2
431 static void loopback_bytepos_update(struct loopback_pcm
*dpcm
,
436 unsigned long last_pos
;
438 last_pos
= byte_pos(dpcm
, dpcm
->irq_pos
);
439 dpcm
->irq_pos
+= delta
* dpcm
->pcm_bps
;
440 count
= byte_pos(dpcm
, dpcm
->irq_pos
) - last_pos
;
443 if (cmd
== BYTEPOS_UPDATE_CLEAR
)
444 clear_capture_buf(dpcm
, count
);
445 else if (cmd
== BYTEPOS_UPDATE_COPY
)
446 copy_play_buf(dpcm
->cable
->streams
[SNDRV_PCM_STREAM_PLAYBACK
],
447 dpcm
->cable
->streams
[SNDRV_PCM_STREAM_CAPTURE
],
449 dpcm
->buf_pos
+= count
;
450 dpcm
->buf_pos
%= dpcm
->pcm_buffer_size
;
451 if (dpcm
->irq_pos
>= dpcm
->period_size_frac
) {
452 dpcm
->irq_pos
%= dpcm
->period_size_frac
;
453 dpcm
->period_update_pending
= 1;
457 static void loopback_pos_update(struct loopback_cable
*cable
)
459 struct loopback_pcm
*dpcm_play
=
460 cable
->streams
[SNDRV_PCM_STREAM_PLAYBACK
];
461 struct loopback_pcm
*dpcm_capt
=
462 cable
->streams
[SNDRV_PCM_STREAM_CAPTURE
];
463 unsigned long delta_play
= 0, delta_capt
= 0;
465 spin_lock(&cable
->lock
);
466 if (cable
->running
& (1 << SNDRV_PCM_STREAM_PLAYBACK
)) {
467 delta_play
= jiffies
- dpcm_play
->last_jiffies
;
468 dpcm_play
->last_jiffies
+= delta_play
;
471 if (cable
->running
& (1 << SNDRV_PCM_STREAM_CAPTURE
)) {
472 delta_capt
= jiffies
- dpcm_capt
->last_jiffies
;
473 dpcm_capt
->last_jiffies
+= delta_capt
;
476 if (delta_play
== 0 && delta_capt
== 0) {
477 spin_unlock(&cable
->lock
);
481 if (delta_play
> delta_capt
) {
482 loopback_bytepos_update(dpcm_play
, delta_play
- delta_capt
,
483 BYTEPOS_UPDATE_POSONLY
);
484 delta_play
= delta_capt
;
485 } else if (delta_play
< delta_capt
) {
486 loopback_bytepos_update(dpcm_capt
, delta_capt
- delta_play
,
487 BYTEPOS_UPDATE_CLEAR
);
488 delta_capt
= delta_play
;
491 if (delta_play
== 0 && delta_capt
== 0) {
492 spin_unlock(&cable
->lock
);
495 /* note delta_capt == delta_play at this moment */
496 loopback_bytepos_update(dpcm_capt
, delta_capt
, BYTEPOS_UPDATE_COPY
);
497 loopback_bytepos_update(dpcm_play
, delta_play
, BYTEPOS_UPDATE_POSONLY
);
498 spin_unlock(&cable
->lock
);
501 static void loopback_timer_function(unsigned long data
)
503 struct loopback_pcm
*dpcm
= (struct loopback_pcm
*)data
;
506 loopback_pos_update(dpcm
->cable
);
507 stream
= dpcm
->substream
->stream
;
508 if (dpcm
->cable
->running
& (1 << stream
))
509 loopback_timer_start(dpcm
);
510 if (dpcm
->period_update_pending
) {
511 dpcm
->period_update_pending
= 0;
512 if (dpcm
->cable
->running
& (1 << stream
))
513 snd_pcm_period_elapsed(dpcm
->substream
);
517 static snd_pcm_uframes_t
loopback_pointer(struct snd_pcm_substream
*substream
)
519 struct snd_pcm_runtime
*runtime
= substream
->runtime
;
520 struct loopback_pcm
*dpcm
= runtime
->private_data
;
522 loopback_pos_update(dpcm
->cable
);
523 return bytes_to_frames(runtime
, dpcm
->buf_pos
);
526 static struct snd_pcm_hardware loopback_pcm_hardware
=
528 .info
= (SNDRV_PCM_INFO_INTERLEAVED
| SNDRV_PCM_INFO_MMAP
|
529 SNDRV_PCM_INFO_MMAP_VALID
),
530 .formats
= (SNDRV_PCM_FMTBIT_S16_LE
| SNDRV_PCM_FMTBIT_S16_BE
|
531 SNDRV_PCM_FMTBIT_S32_LE
| SNDRV_PCM_FMTBIT_S32_BE
|
532 SNDRV_PCM_FMTBIT_FLOAT_LE
| SNDRV_PCM_FMTBIT_FLOAT_BE
),
533 .rates
= SNDRV_PCM_RATE_CONTINUOUS
| SNDRV_PCM_RATE_8000_192000
,
538 .buffer_bytes_max
= 2 * 1024 * 1024,
539 .period_bytes_min
= 64,
540 /* note check overflow in frac_pos() using pcm_rate_shift before
541 changing period_bytes_max value */
542 .period_bytes_max
= 1024 * 1024,
548 static void loopback_runtime_free(struct snd_pcm_runtime
*runtime
)
550 struct loopback_pcm
*dpcm
= runtime
->private_data
;
554 static int loopback_hw_params(struct snd_pcm_substream
*substream
,
555 struct snd_pcm_hw_params
*params
)
557 return snd_pcm_lib_malloc_pages(substream
, params_buffer_bytes(params
));
560 static int loopback_hw_free(struct snd_pcm_substream
*substream
)
562 struct snd_pcm_runtime
*runtime
= substream
->runtime
;
563 struct loopback_pcm
*dpcm
= runtime
->private_data
;
564 struct loopback_cable
*cable
= dpcm
->cable
;
566 mutex_lock(&dpcm
->loopback
->cable_lock
);
567 cable
->valid
&= ~(1 << substream
->stream
);
568 mutex_unlock(&dpcm
->loopback
->cable_lock
);
569 return snd_pcm_lib_free_pages(substream
);
572 static unsigned int get_cable_index(struct snd_pcm_substream
*substream
)
574 if (!substream
->pcm
->device
)
575 return substream
->stream
;
577 return !substream
->stream
;
580 static int rule_format(struct snd_pcm_hw_params
*params
,
581 struct snd_pcm_hw_rule
*rule
)
584 struct snd_pcm_hardware
*hw
= rule
->private;
585 struct snd_mask
*maskp
= hw_param_mask(params
, rule
->var
);
587 maskp
->bits
[0] &= (u_int32_t
)hw
->formats
;
588 maskp
->bits
[1] &= (u_int32_t
)(hw
->formats
>> 32);
589 memset(maskp
->bits
+ 2, 0, (SNDRV_MASK_MAX
-64) / 8); /* clear rest */
590 if (! maskp
->bits
[0] && ! maskp
->bits
[1])
595 static int rule_rate(struct snd_pcm_hw_params
*params
,
596 struct snd_pcm_hw_rule
*rule
)
598 struct snd_pcm_hardware
*hw
= rule
->private;
599 struct snd_interval t
;
601 t
.min
= hw
->rate_min
;
602 t
.max
= hw
->rate_max
;
603 t
.openmin
= t
.openmax
= 0;
605 return snd_interval_refine(hw_param_interval(params
, rule
->var
), &t
);
608 static int rule_channels(struct snd_pcm_hw_params
*params
,
609 struct snd_pcm_hw_rule
*rule
)
611 struct snd_pcm_hardware
*hw
= rule
->private;
612 struct snd_interval t
;
614 t
.min
= hw
->channels_min
;
615 t
.max
= hw
->channels_max
;
616 t
.openmin
= t
.openmax
= 0;
618 return snd_interval_refine(hw_param_interval(params
, rule
->var
), &t
);
621 static int loopback_open(struct snd_pcm_substream
*substream
)
623 struct snd_pcm_runtime
*runtime
= substream
->runtime
;
624 struct loopback
*loopback
= substream
->private_data
;
625 struct loopback_pcm
*dpcm
;
626 struct loopback_cable
*cable
;
628 int dev
= get_cable_index(substream
);
630 mutex_lock(&loopback
->cable_lock
);
631 dpcm
= kzalloc(sizeof(*dpcm
), GFP_KERNEL
);
636 dpcm
->loopback
= loopback
;
637 dpcm
->substream
= substream
;
638 setup_timer(&dpcm
->timer
, loopback_timer_function
,
639 (unsigned long)dpcm
);
641 cable
= loopback
->cables
[substream
->number
][dev
];
643 cable
= kzalloc(sizeof(*cable
), GFP_KERNEL
);
649 spin_lock_init(&cable
->lock
);
650 cable
->hw
= loopback_pcm_hardware
;
651 loopback
->cables
[substream
->number
][dev
] = cable
;
654 cable
->streams
[substream
->stream
] = dpcm
;
656 snd_pcm_hw_constraint_integer(runtime
, SNDRV_PCM_HW_PARAM_PERIODS
);
658 /* use dynamic rules based on actual runtime->hw values */
659 /* note that the default rules created in the PCM midlevel code */
660 /* are cached -> they do not reflect the actual state */
661 err
= snd_pcm_hw_rule_add(runtime
, 0,
662 SNDRV_PCM_HW_PARAM_FORMAT
,
663 rule_format
, &runtime
->hw
,
664 SNDRV_PCM_HW_PARAM_FORMAT
, -1);
667 err
= snd_pcm_hw_rule_add(runtime
, 0,
668 SNDRV_PCM_HW_PARAM_RATE
,
669 rule_rate
, &runtime
->hw
,
670 SNDRV_PCM_HW_PARAM_RATE
, -1);
673 err
= snd_pcm_hw_rule_add(runtime
, 0,
674 SNDRV_PCM_HW_PARAM_CHANNELS
,
675 rule_channels
, &runtime
->hw
,
676 SNDRV_PCM_HW_PARAM_CHANNELS
, -1);
680 runtime
->private_data
= dpcm
;
681 runtime
->private_free
= loopback_runtime_free
;
682 if (get_notify(dpcm
))
683 runtime
->hw
= loopback_pcm_hardware
;
685 runtime
->hw
= cable
->hw
;
687 mutex_unlock(&loopback
->cable_lock
);
691 static int loopback_close(struct snd_pcm_substream
*substream
)
693 struct loopback
*loopback
= substream
->private_data
;
694 struct loopback_pcm
*dpcm
= substream
->runtime
->private_data
;
695 struct loopback_cable
*cable
;
696 int dev
= get_cable_index(substream
);
698 loopback_timer_stop(dpcm
);
699 mutex_lock(&loopback
->cable_lock
);
700 cable
= loopback
->cables
[substream
->number
][dev
];
701 if (cable
->streams
[!substream
->stream
]) {
702 /* other stream is still alive */
703 cable
->streams
[substream
->stream
] = NULL
;
706 loopback
->cables
[substream
->number
][dev
] = NULL
;
709 mutex_unlock(&loopback
->cable_lock
);
713 static struct snd_pcm_ops loopback_playback_ops
= {
714 .open
= loopback_open
,
715 .close
= loopback_close
,
716 .ioctl
= snd_pcm_lib_ioctl
,
717 .hw_params
= loopback_hw_params
,
718 .hw_free
= loopback_hw_free
,
719 .prepare
= loopback_prepare
,
720 .trigger
= loopback_trigger
,
721 .pointer
= loopback_pointer
,
724 static struct snd_pcm_ops loopback_capture_ops
= {
725 .open
= loopback_open
,
726 .close
= loopback_close
,
727 .ioctl
= snd_pcm_lib_ioctl
,
728 .hw_params
= loopback_hw_params
,
729 .hw_free
= loopback_hw_free
,
730 .prepare
= loopback_prepare
,
731 .trigger
= loopback_trigger
,
732 .pointer
= loopback_pointer
,
735 static int __devinit
loopback_pcm_new(struct loopback
*loopback
,
736 int device
, int substreams
)
741 err
= snd_pcm_new(loopback
->card
, "Loopback PCM", device
,
742 substreams
, substreams
, &pcm
);
745 snd_pcm_set_ops(pcm
, SNDRV_PCM_STREAM_PLAYBACK
, &loopback_playback_ops
);
746 snd_pcm_set_ops(pcm
, SNDRV_PCM_STREAM_CAPTURE
, &loopback_capture_ops
);
748 pcm
->private_data
= loopback
;
750 strcpy(pcm
->name
, "Loopback PCM");
752 loopback
->pcm
[device
] = pcm
;
754 snd_pcm_lib_preallocate_pages_for_all(pcm
, SNDRV_DMA_TYPE_CONTINUOUS
,
755 snd_dma_continuous_data(GFP_KERNEL
),
760 static int loopback_rate_shift_info(struct snd_kcontrol
*kcontrol
,
761 struct snd_ctl_elem_info
*uinfo
)
763 uinfo
->type
= SNDRV_CTL_ELEM_TYPE_INTEGER
;
765 uinfo
->value
.integer
.min
= 80000;
766 uinfo
->value
.integer
.max
= 120000;
767 uinfo
->value
.integer
.step
= 1;
771 static int loopback_rate_shift_get(struct snd_kcontrol
*kcontrol
,
772 struct snd_ctl_elem_value
*ucontrol
)
774 struct loopback
*loopback
= snd_kcontrol_chip(kcontrol
);
776 ucontrol
->value
.integer
.value
[0] =
777 loopback
->setup
[kcontrol
->id
.subdevice
]
778 [kcontrol
->id
.device
].rate_shift
;
782 static int loopback_rate_shift_put(struct snd_kcontrol
*kcontrol
,
783 struct snd_ctl_elem_value
*ucontrol
)
785 struct loopback
*loopback
= snd_kcontrol_chip(kcontrol
);
789 val
= ucontrol
->value
.integer
.value
[0];
794 mutex_lock(&loopback
->cable_lock
);
795 if (val
!= loopback
->setup
[kcontrol
->id
.subdevice
]
796 [kcontrol
->id
.device
].rate_shift
) {
797 loopback
->setup
[kcontrol
->id
.subdevice
]
798 [kcontrol
->id
.device
].rate_shift
= val
;
801 mutex_unlock(&loopback
->cable_lock
);
805 static int loopback_notify_get(struct snd_kcontrol
*kcontrol
,
806 struct snd_ctl_elem_value
*ucontrol
)
808 struct loopback
*loopback
= snd_kcontrol_chip(kcontrol
);
810 ucontrol
->value
.integer
.value
[0] =
811 loopback
->setup
[kcontrol
->id
.subdevice
]
812 [kcontrol
->id
.device
].notify
;
816 static int loopback_notify_put(struct snd_kcontrol
*kcontrol
,
817 struct snd_ctl_elem_value
*ucontrol
)
819 struct loopback
*loopback
= snd_kcontrol_chip(kcontrol
);
823 val
= ucontrol
->value
.integer
.value
[0] ? 1 : 0;
824 if (val
!= loopback
->setup
[kcontrol
->id
.subdevice
]
825 [kcontrol
->id
.device
].notify
) {
826 loopback
->setup
[kcontrol
->id
.subdevice
]
827 [kcontrol
->id
.device
].notify
= val
;
833 static int loopback_active_get(struct snd_kcontrol
*kcontrol
,
834 struct snd_ctl_elem_value
*ucontrol
)
836 struct loopback
*loopback
= snd_kcontrol_chip(kcontrol
);
837 struct loopback_cable
*cable
= loopback
->cables
838 [kcontrol
->id
.subdevice
][kcontrol
->id
.device
^ 1];
839 unsigned int val
= 0;
842 val
= (cable
->running
& (1 << SNDRV_PCM_STREAM_PLAYBACK
)) ?
844 ucontrol
->value
.integer
.value
[0] = val
;
848 static int loopback_format_info(struct snd_kcontrol
*kcontrol
,
849 struct snd_ctl_elem_info
*uinfo
)
851 uinfo
->type
= SNDRV_CTL_ELEM_TYPE_INTEGER
;
853 uinfo
->value
.integer
.min
= 0;
854 uinfo
->value
.integer
.max
= SNDRV_PCM_FORMAT_LAST
;
855 uinfo
->value
.integer
.step
= 1;
859 static int loopback_format_get(struct snd_kcontrol
*kcontrol
,
860 struct snd_ctl_elem_value
*ucontrol
)
862 struct loopback
*loopback
= snd_kcontrol_chip(kcontrol
);
864 ucontrol
->value
.integer
.value
[0] =
865 loopback
->setup
[kcontrol
->id
.subdevice
]
866 [kcontrol
->id
.device
].format
;
870 static int loopback_rate_info(struct snd_kcontrol
*kcontrol
,
871 struct snd_ctl_elem_info
*uinfo
)
873 uinfo
->type
= SNDRV_CTL_ELEM_TYPE_INTEGER
;
875 uinfo
->value
.integer
.min
= 0;
876 uinfo
->value
.integer
.max
= 192000;
877 uinfo
->value
.integer
.step
= 1;
881 static int loopback_rate_get(struct snd_kcontrol
*kcontrol
,
882 struct snd_ctl_elem_value
*ucontrol
)
884 struct loopback
*loopback
= snd_kcontrol_chip(kcontrol
);
886 ucontrol
->value
.integer
.value
[0] =
887 loopback
->setup
[kcontrol
->id
.subdevice
]
888 [kcontrol
->id
.device
].rate
;
892 static int loopback_channels_info(struct snd_kcontrol
*kcontrol
,
893 struct snd_ctl_elem_info
*uinfo
)
895 uinfo
->type
= SNDRV_CTL_ELEM_TYPE_INTEGER
;
897 uinfo
->value
.integer
.min
= 1;
898 uinfo
->value
.integer
.max
= 1024;
899 uinfo
->value
.integer
.step
= 1;
903 static int loopback_channels_get(struct snd_kcontrol
*kcontrol
,
904 struct snd_ctl_elem_value
*ucontrol
)
906 struct loopback
*loopback
= snd_kcontrol_chip(kcontrol
);
908 ucontrol
->value
.integer
.value
[0] =
909 loopback
->setup
[kcontrol
->id
.subdevice
]
910 [kcontrol
->id
.device
].channels
;
914 static struct snd_kcontrol_new loopback_controls
[] __devinitdata
= {
916 .iface
= SNDRV_CTL_ELEM_IFACE_PCM
,
917 .name
= "PCM Rate Shift 100000",
918 .info
= loopback_rate_shift_info
,
919 .get
= loopback_rate_shift_get
,
920 .put
= loopback_rate_shift_put
,
923 .iface
= SNDRV_CTL_ELEM_IFACE_PCM
,
924 .name
= "PCM Notify",
925 .info
= snd_ctl_boolean_mono_info
,
926 .get
= loopback_notify_get
,
927 .put
= loopback_notify_put
,
931 .access
= SNDRV_CTL_ELEM_ACCESS_READ
,
932 .iface
= SNDRV_CTL_ELEM_IFACE_PCM
,
933 .name
= "PCM Slave Active",
934 .info
= snd_ctl_boolean_mono_info
,
935 .get
= loopback_active_get
,
939 .access
= SNDRV_CTL_ELEM_ACCESS_READ
,
940 .iface
= SNDRV_CTL_ELEM_IFACE_PCM
,
941 .name
= "PCM Slave Format",
942 .info
= loopback_format_info
,
943 .get
= loopback_format_get
947 .access
= SNDRV_CTL_ELEM_ACCESS_READ
,
948 .iface
= SNDRV_CTL_ELEM_IFACE_PCM
,
949 .name
= "PCM Slave Rate",
950 .info
= loopback_rate_info
,
951 .get
= loopback_rate_get
953 #define CHANNELS_IDX 5
955 .access
= SNDRV_CTL_ELEM_ACCESS_READ
,
956 .iface
= SNDRV_CTL_ELEM_IFACE_PCM
,
957 .name
= "PCM Slave Channels",
958 .info
= loopback_channels_info
,
959 .get
= loopback_channels_get
963 static int __devinit
loopback_mixer_new(struct loopback
*loopback
, int notify
)
965 struct snd_card
*card
= loopback
->card
;
967 struct snd_kcontrol
*kctl
;
968 struct loopback_setup
*setup
;
969 int err
, dev
, substr
, substr_count
, idx
;
971 strcpy(card
->mixername
, "Loopback Mixer");
972 for (dev
= 0; dev
< 2; dev
++) {
973 pcm
= loopback
->pcm
[dev
];
975 pcm
->streams
[SNDRV_PCM_STREAM_CAPTURE
].substream_count
;
976 for (substr
= 0; substr
< substr_count
; substr
++) {
977 setup
= &loopback
->setup
[substr
][dev
];
978 setup
->notify
= notify
;
979 setup
->rate_shift
= NO_PITCH
;
980 setup
->format
= SNDRV_PCM_FORMAT_S16_LE
;
983 for (idx
= 0; idx
< ARRAY_SIZE(loopback_controls
);
985 kctl
= snd_ctl_new1(&loopback_controls
[idx
],
989 kctl
->id
.device
= dev
;
990 kctl
->id
.subdevice
= substr
;
993 setup
->active_id
= kctl
->id
;
996 setup
->format_id
= kctl
->id
;
999 setup
->rate_id
= kctl
->id
;
1002 setup
->channels_id
= kctl
->id
;
1007 err
= snd_ctl_add(card
, kctl
);
1016 #ifdef CONFIG_PROC_FS
1018 static void print_dpcm_info(struct snd_info_buffer
*buffer
,
1019 struct loopback_pcm
*dpcm
,
1022 snd_iprintf(buffer
, " %s\n", id
);
1024 snd_iprintf(buffer
, " inactive\n");
1027 snd_iprintf(buffer
, " buffer_size:\t%u\n", dpcm
->pcm_buffer_size
);
1028 snd_iprintf(buffer
, " buffer_pos:\t\t%u\n", dpcm
->buf_pos
);
1029 snd_iprintf(buffer
, " silent_size:\t%u\n", dpcm
->silent_size
);
1030 snd_iprintf(buffer
, " period_size:\t%u\n", dpcm
->pcm_period_size
);
1031 snd_iprintf(buffer
, " bytes_per_sec:\t%u\n", dpcm
->pcm_bps
);
1032 snd_iprintf(buffer
, " sample_align:\t%u\n", dpcm
->pcm_salign
);
1033 snd_iprintf(buffer
, " rate_shift:\t\t%u\n", dpcm
->pcm_rate_shift
);
1034 snd_iprintf(buffer
, " update_pending:\t%u\n",
1035 dpcm
->period_update_pending
);
1036 snd_iprintf(buffer
, " irq_pos:\t\t%u\n", dpcm
->irq_pos
);
1037 snd_iprintf(buffer
, " period_frac:\t%u\n", dpcm
->period_size_frac
);
1038 snd_iprintf(buffer
, " last_jiffies:\t%lu (%lu)\n",
1039 dpcm
->last_jiffies
, jiffies
);
1040 snd_iprintf(buffer
, " timer_expires:\t%lu\n", dpcm
->timer
.expires
);
1043 static void print_substream_info(struct snd_info_buffer
*buffer
,
1044 struct loopback
*loopback
,
1048 struct loopback_cable
*cable
= loopback
->cables
[sub
][num
];
1050 snd_iprintf(buffer
, "Cable %i substream %i:\n", num
, sub
);
1051 if (cable
== NULL
) {
1052 snd_iprintf(buffer
, " inactive\n");
1055 snd_iprintf(buffer
, " valid: %u\n", cable
->valid
);
1056 snd_iprintf(buffer
, " running: %u\n", cable
->running
);
1057 print_dpcm_info(buffer
, cable
->streams
[0], "Playback");
1058 print_dpcm_info(buffer
, cable
->streams
[1], "Capture");
1061 static void print_cable_info(struct snd_info_entry
*entry
,
1062 struct snd_info_buffer
*buffer
)
1064 struct loopback
*loopback
= entry
->private_data
;
1067 mutex_lock(&loopback
->cable_lock
);
1068 num
= entry
->name
[strlen(entry
->name
)-1];
1069 num
= num
== '0' ? 0 : 1;
1070 for (sub
= 0; sub
< MAX_PCM_SUBSTREAMS
; sub
++)
1071 print_substream_info(buffer
, loopback
, sub
, num
);
1072 mutex_unlock(&loopback
->cable_lock
);
1075 static int __devinit
loopback_proc_new(struct loopback
*loopback
, int cidx
)
1078 struct snd_info_entry
*entry
;
1081 snprintf(name
, sizeof(name
), "cable#%d", cidx
);
1082 err
= snd_card_proc_new(loopback
->card
, name
, &entry
);
1086 snd_info_set_text_ops(entry
, loopback
, print_cable_info
);
1090 #else /* !CONFIG_PROC_FS */
1092 #define loopback_proc_new(loopback, cidx) do { } while (0)
1096 static int __devinit
loopback_probe(struct platform_device
*devptr
)
1098 struct snd_card
*card
;
1099 struct loopback
*loopback
;
1100 int dev
= devptr
->id
;
1103 err
= snd_card_create(index
[dev
], id
[dev
], THIS_MODULE
,
1104 sizeof(struct loopback
), &card
);
1107 loopback
= card
->private_data
;
1109 if (pcm_substreams
[dev
] < 1)
1110 pcm_substreams
[dev
] = 1;
1111 if (pcm_substreams
[dev
] > MAX_PCM_SUBSTREAMS
)
1112 pcm_substreams
[dev
] = MAX_PCM_SUBSTREAMS
;
1114 loopback
->card
= card
;
1115 mutex_init(&loopback
->cable_lock
);
1117 err
= loopback_pcm_new(loopback
, 0, pcm_substreams
[dev
]);
1120 err
= loopback_pcm_new(loopback
, 1, pcm_substreams
[dev
]);
1123 err
= loopback_mixer_new(loopback
, pcm_notify
[dev
] ? 1 : 0);
1126 loopback_proc_new(loopback
, 0);
1127 loopback_proc_new(loopback
, 1);
1128 strcpy(card
->driver
, "Loopback");
1129 strcpy(card
->shortname
, "Loopback");
1130 sprintf(card
->longname
, "Loopback %i", dev
+ 1);
1131 err
= snd_card_register(card
);
1133 platform_set_drvdata(devptr
, card
);
1137 snd_card_free(card
);
1141 static int __devexit
loopback_remove(struct platform_device
*devptr
)
1143 snd_card_free(platform_get_drvdata(devptr
));
1144 platform_set_drvdata(devptr
, NULL
);
1149 static int loopback_suspend(struct platform_device
*pdev
,
1152 struct snd_card
*card
= platform_get_drvdata(pdev
);
1153 struct loopback
*loopback
= card
->private_data
;
1155 snd_power_change_state(card
, SNDRV_CTL_POWER_D3hot
);
1157 snd_pcm_suspend_all(loopback
->pcm
[0]);
1158 snd_pcm_suspend_all(loopback
->pcm
[1]);
1162 static int loopback_resume(struct platform_device
*pdev
)
1164 struct snd_card
*card
= platform_get_drvdata(pdev
);
1166 snd_power_change_state(card
, SNDRV_CTL_POWER_D0
);
1171 #define SND_LOOPBACK_DRIVER "snd_aloop"
1173 static struct platform_driver loopback_driver
= {
1174 .probe
= loopback_probe
,
1175 .remove
= __devexit_p(loopback_remove
),
1177 .suspend
= loopback_suspend
,
1178 .resume
= loopback_resume
,
1181 .name
= SND_LOOPBACK_DRIVER
1185 static void loopback_unregister_all(void)
1189 for (i
= 0; i
< ARRAY_SIZE(devices
); ++i
)
1190 platform_device_unregister(devices
[i
]);
1191 platform_driver_unregister(&loopback_driver
);
1194 static int __init
alsa_card_loopback_init(void)
1198 err
= platform_driver_register(&loopback_driver
);
1204 for (i
= 0; i
< SNDRV_CARDS
; i
++) {
1205 struct platform_device
*device
;
1208 device
= platform_device_register_simple(SND_LOOPBACK_DRIVER
,
1212 if (!platform_get_drvdata(device
)) {
1213 platform_device_unregister(device
);
1216 devices
[i
] = device
;
1221 printk(KERN_ERR
"aloop: No loopback enabled\n");
1223 loopback_unregister_all();
1229 static void __exit
alsa_card_loopback_exit(void)
1231 loopback_unregister_all();
1234 module_init(alsa_card_loopback_init
)
1235 module_exit(alsa_card_loopback_exit
)