Commit | Line | Data |
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31ef9134 CL |
1 | /* |
2 | * Audio and Music Data Transmission Protocol (IEC 61883-6) streams | |
3 | * with Common Isochronous Packet (IEC 61883-1) headers | |
4 | * | |
5 | * Copyright (c) Clemens Ladisch <clemens@ladisch.de> | |
6 | * Licensed under the terms of the GNU General Public License, version 2. | |
7 | */ | |
8 | ||
9 | #include <linux/device.h> | |
10 | #include <linux/err.h> | |
11 | #include <linux/firewire.h> | |
12 | #include <linux/module.h> | |
13 | #include <linux/slab.h> | |
14 | #include <sound/pcm.h> | |
15 | #include "amdtp.h" | |
16 | ||
17 | #define TICKS_PER_CYCLE 3072 | |
18 | #define CYCLES_PER_SECOND 8000 | |
19 | #define TICKS_PER_SECOND (TICKS_PER_CYCLE * CYCLES_PER_SECOND) | |
20 | ||
21 | #define TRANSFER_DELAY_TICKS 0x2e00 /* 479.17 µs */ | |
22 | ||
23 | #define TAG_CIP 1 | |
24 | ||
25 | #define CIP_EOH (1u << 31) | |
26 | #define CIP_FMT_AM (0x10 << 24) | |
27 | #define AMDTP_FDF_AM824 (0 << 19) | |
28 | #define AMDTP_FDF_SFC_SHIFT 16 | |
29 | ||
30 | /* TODO: make these configurable */ | |
31 | #define INTERRUPT_INTERVAL 16 | |
32 | #define QUEUE_LENGTH 48 | |
33 | ||
34 | /** | |
35 | * amdtp_out_stream_init - initialize an AMDTP output stream structure | |
36 | * @s: the AMDTP output stream to initialize | |
37 | * @unit: the target of the stream | |
38 | * @flags: the packet transmission method to use | |
39 | */ | |
40 | int amdtp_out_stream_init(struct amdtp_out_stream *s, struct fw_unit *unit, | |
41 | enum cip_out_flags flags) | |
42 | { | |
43 | if (flags != CIP_NONBLOCKING) | |
44 | return -EINVAL; | |
45 | ||
46 | s->unit = fw_unit_get(unit); | |
47 | s->flags = flags; | |
48 | s->context = ERR_PTR(-1); | |
49 | mutex_init(&s->mutex); | |
ec00f5e4 | 50 | s->packet_index = 0; |
31ef9134 CL |
51 | |
52 | return 0; | |
53 | } | |
54 | EXPORT_SYMBOL(amdtp_out_stream_init); | |
55 | ||
56 | /** | |
57 | * amdtp_out_stream_destroy - free stream resources | |
58 | * @s: the AMDTP output stream to destroy | |
59 | */ | |
60 | void amdtp_out_stream_destroy(struct amdtp_out_stream *s) | |
61 | { | |
62 | WARN_ON(!IS_ERR(s->context)); | |
63 | mutex_destroy(&s->mutex); | |
64 | fw_unit_put(s->unit); | |
65 | } | |
66 | EXPORT_SYMBOL(amdtp_out_stream_destroy); | |
67 | ||
68 | /** | |
69 | * amdtp_out_stream_set_rate - set the sample rate | |
70 | * @s: the AMDTP output stream to configure | |
71 | * @rate: the sample rate | |
72 | * | |
73 | * The sample rate must be set before the stream is started, and must not be | |
74 | * changed while the stream is running. | |
75 | */ | |
76 | void amdtp_out_stream_set_rate(struct amdtp_out_stream *s, unsigned int rate) | |
77 | { | |
78 | static const struct { | |
79 | unsigned int rate; | |
80 | unsigned int syt_interval; | |
81 | } rate_info[] = { | |
82 | [CIP_SFC_32000] = { 32000, 8, }, | |
83 | [CIP_SFC_44100] = { 44100, 8, }, | |
84 | [CIP_SFC_48000] = { 48000, 8, }, | |
85 | [CIP_SFC_88200] = { 88200, 16, }, | |
86 | [CIP_SFC_96000] = { 96000, 16, }, | |
87 | [CIP_SFC_176400] = { 176400, 32, }, | |
88 | [CIP_SFC_192000] = { 192000, 32, }, | |
89 | }; | |
90 | unsigned int sfc; | |
91 | ||
92 | if (WARN_ON(!IS_ERR(s->context))) | |
93 | return; | |
94 | ||
95 | for (sfc = 0; sfc < ARRAY_SIZE(rate_info); ++sfc) | |
96 | if (rate_info[sfc].rate == rate) { | |
97 | s->sfc = sfc; | |
98 | s->syt_interval = rate_info[sfc].syt_interval; | |
99 | return; | |
100 | } | |
101 | WARN_ON(1); | |
102 | } | |
103 | EXPORT_SYMBOL(amdtp_out_stream_set_rate); | |
104 | ||
105 | /** | |
106 | * amdtp_out_stream_get_max_payload - get the stream's packet size | |
107 | * @s: the AMDTP output stream | |
108 | * | |
109 | * This function must not be called before the stream has been configured | |
110 | * with amdtp_out_stream_set_hw_params(), amdtp_out_stream_set_pcm(), and | |
111 | * amdtp_out_stream_set_midi(). | |
112 | */ | |
113 | unsigned int amdtp_out_stream_get_max_payload(struct amdtp_out_stream *s) | |
114 | { | |
115 | static const unsigned int max_data_blocks[] = { | |
116 | [CIP_SFC_32000] = 4, | |
117 | [CIP_SFC_44100] = 6, | |
118 | [CIP_SFC_48000] = 6, | |
119 | [CIP_SFC_88200] = 12, | |
120 | [CIP_SFC_96000] = 12, | |
121 | [CIP_SFC_176400] = 23, | |
122 | [CIP_SFC_192000] = 24, | |
123 | }; | |
124 | ||
125 | s->data_block_quadlets = s->pcm_channels; | |
126 | s->data_block_quadlets += DIV_ROUND_UP(s->midi_ports, 8); | |
127 | ||
128 | return 8 + max_data_blocks[s->sfc] * 4 * s->data_block_quadlets; | |
129 | } | |
130 | EXPORT_SYMBOL(amdtp_out_stream_get_max_payload); | |
131 | ||
132 | static void amdtp_write_s16(struct amdtp_out_stream *s, | |
133 | struct snd_pcm_substream *pcm, | |
134 | __be32 *buffer, unsigned int frames); | |
135 | static void amdtp_write_s32(struct amdtp_out_stream *s, | |
136 | struct snd_pcm_substream *pcm, | |
137 | __be32 *buffer, unsigned int frames); | |
138 | ||
139 | /** | |
140 | * amdtp_out_stream_set_pcm_format - set the PCM format | |
141 | * @s: the AMDTP output stream to configure | |
142 | * @format: the format of the ALSA PCM device | |
143 | * | |
144 | * The sample format must be set before the stream is started, and must not be | |
145 | * changed while the stream is running. | |
146 | */ | |
147 | void amdtp_out_stream_set_pcm_format(struct amdtp_out_stream *s, | |
148 | snd_pcm_format_t format) | |
149 | { | |
150 | if (WARN_ON(!IS_ERR(s->context))) | |
151 | return; | |
152 | ||
153 | switch (format) { | |
154 | default: | |
155 | WARN_ON(1); | |
156 | /* fall through */ | |
157 | case SNDRV_PCM_FORMAT_S16: | |
158 | s->transfer_samples = amdtp_write_s16; | |
159 | break; | |
160 | case SNDRV_PCM_FORMAT_S32: | |
161 | s->transfer_samples = amdtp_write_s32; | |
162 | break; | |
163 | } | |
164 | } | |
165 | EXPORT_SYMBOL(amdtp_out_stream_set_pcm_format); | |
166 | ||
167 | static unsigned int calculate_data_blocks(struct amdtp_out_stream *s) | |
168 | { | |
169 | unsigned int phase, data_blocks; | |
170 | ||
171 | if (!cip_sfc_is_base_44100(s->sfc)) { | |
172 | /* Sample_rate / 8000 is an integer, and precomputed. */ | |
173 | data_blocks = s->data_block_state; | |
174 | } else { | |
175 | phase = s->data_block_state; | |
176 | ||
177 | /* | |
178 | * This calculates the number of data blocks per packet so that | |
179 | * 1) the overall rate is correct and exactly synchronized to | |
180 | * the bus clock, and | |
181 | * 2) packets with a rounded-up number of blocks occur as early | |
182 | * as possible in the sequence (to prevent underruns of the | |
183 | * device's buffer). | |
184 | */ | |
185 | if (s->sfc == CIP_SFC_44100) | |
186 | /* 6 6 5 6 5 6 5 ... */ | |
187 | data_blocks = 5 + ((phase & 1) ^ | |
188 | (phase == 0 || phase >= 40)); | |
189 | else | |
190 | /* 12 11 11 11 11 ... or 23 22 22 22 22 ... */ | |
191 | data_blocks = 11 * (s->sfc >> 1) + (phase == 0); | |
192 | if (++phase >= (80 >> (s->sfc >> 1))) | |
193 | phase = 0; | |
194 | s->data_block_state = phase; | |
195 | } | |
196 | ||
197 | return data_blocks; | |
198 | } | |
199 | ||
200 | static unsigned int calculate_syt(struct amdtp_out_stream *s, | |
201 | unsigned int cycle) | |
202 | { | |
203 | unsigned int syt_offset, phase, index, syt; | |
204 | ||
205 | if (s->last_syt_offset < TICKS_PER_CYCLE) { | |
206 | if (!cip_sfc_is_base_44100(s->sfc)) | |
207 | syt_offset = s->last_syt_offset + s->syt_offset_state; | |
208 | else { | |
209 | /* | |
210 | * The time, in ticks, of the n'th SYT_INTERVAL sample is: | |
211 | * n * SYT_INTERVAL * 24576000 / sample_rate | |
212 | * Modulo TICKS_PER_CYCLE, the difference between successive | |
213 | * elements is about 1386.23. Rounding the results of this | |
214 | * formula to the SYT precision results in a sequence of | |
215 | * differences that begins with: | |
216 | * 1386 1386 1387 1386 1386 1386 1387 1386 1386 1386 1387 ... | |
217 | * This code generates _exactly_ the same sequence. | |
218 | */ | |
219 | phase = s->syt_offset_state; | |
220 | index = phase % 13; | |
221 | syt_offset = s->last_syt_offset; | |
222 | syt_offset += 1386 + ((index && !(index & 3)) || | |
223 | phase == 146); | |
224 | if (++phase >= 147) | |
225 | phase = 0; | |
226 | s->syt_offset_state = phase; | |
227 | } | |
228 | } else | |
229 | syt_offset = s->last_syt_offset - TICKS_PER_CYCLE; | |
230 | s->last_syt_offset = syt_offset; | |
231 | ||
be454366 CL |
232 | if (syt_offset < TICKS_PER_CYCLE) { |
233 | syt_offset += TRANSFER_DELAY_TICKS - TICKS_PER_CYCLE; | |
234 | syt = (cycle + syt_offset / TICKS_PER_CYCLE) << 12; | |
235 | syt += syt_offset % TICKS_PER_CYCLE; | |
31ef9134 | 236 | |
be454366 CL |
237 | return syt & 0xffff; |
238 | } else { | |
239 | return 0xffff; /* no info */ | |
240 | } | |
31ef9134 CL |
241 | } |
242 | ||
243 | static void amdtp_write_s32(struct amdtp_out_stream *s, | |
244 | struct snd_pcm_substream *pcm, | |
245 | __be32 *buffer, unsigned int frames) | |
246 | { | |
247 | struct snd_pcm_runtime *runtime = pcm->runtime; | |
248 | unsigned int channels, remaining_frames, frame_step, i, c; | |
249 | const u32 *src; | |
250 | ||
251 | channels = s->pcm_channels; | |
252 | src = (void *)runtime->dma_area + | |
253 | s->pcm_buffer_pointer * (runtime->frame_bits / 8); | |
254 | remaining_frames = runtime->buffer_size - s->pcm_buffer_pointer; | |
255 | frame_step = s->data_block_quadlets - channels; | |
256 | ||
257 | for (i = 0; i < frames; ++i) { | |
258 | for (c = 0; c < channels; ++c) { | |
259 | *buffer = cpu_to_be32((*src >> 8) | 0x40000000); | |
260 | src++; | |
261 | buffer++; | |
262 | } | |
263 | buffer += frame_step; | |
264 | if (--remaining_frames == 0) | |
265 | src = (void *)runtime->dma_area; | |
266 | } | |
267 | } | |
268 | ||
269 | static void amdtp_write_s16(struct amdtp_out_stream *s, | |
270 | struct snd_pcm_substream *pcm, | |
271 | __be32 *buffer, unsigned int frames) | |
272 | { | |
273 | struct snd_pcm_runtime *runtime = pcm->runtime; | |
274 | unsigned int channels, remaining_frames, frame_step, i, c; | |
275 | const u16 *src; | |
276 | ||
277 | channels = s->pcm_channels; | |
278 | src = (void *)runtime->dma_area + | |
279 | s->pcm_buffer_pointer * (runtime->frame_bits / 8); | |
280 | remaining_frames = runtime->buffer_size - s->pcm_buffer_pointer; | |
281 | frame_step = s->data_block_quadlets - channels; | |
282 | ||
283 | for (i = 0; i < frames; ++i) { | |
284 | for (c = 0; c < channels; ++c) { | |
285 | *buffer = cpu_to_be32((*src << 8) | 0x40000000); | |
286 | src++; | |
287 | buffer++; | |
288 | } | |
289 | buffer += frame_step; | |
290 | if (--remaining_frames == 0) | |
291 | src = (void *)runtime->dma_area; | |
292 | } | |
293 | } | |
294 | ||
295 | static void amdtp_fill_pcm_silence(struct amdtp_out_stream *s, | |
296 | __be32 *buffer, unsigned int frames) | |
297 | { | |
298 | unsigned int i, c; | |
299 | ||
300 | for (i = 0; i < frames; ++i) { | |
301 | for (c = 0; c < s->pcm_channels; ++c) | |
302 | buffer[c] = cpu_to_be32(0x40000000); | |
303 | buffer += s->data_block_quadlets; | |
304 | } | |
305 | } | |
306 | ||
307 | static void amdtp_fill_midi(struct amdtp_out_stream *s, | |
308 | __be32 *buffer, unsigned int frames) | |
309 | { | |
310 | unsigned int i; | |
311 | ||
312 | for (i = 0; i < frames; ++i) | |
313 | buffer[s->pcm_channels + i * s->data_block_quadlets] = | |
314 | cpu_to_be32(0x80000000); | |
315 | } | |
316 | ||
317 | static void queue_out_packet(struct amdtp_out_stream *s, unsigned int cycle) | |
318 | { | |
319 | __be32 *buffer; | |
ec00f5e4 | 320 | unsigned int index, data_blocks, syt, ptr; |
31ef9134 CL |
321 | struct snd_pcm_substream *pcm; |
322 | struct fw_iso_packet packet; | |
323 | int err; | |
324 | ||
ec00f5e4 CL |
325 | if (s->packet_index < 0) |
326 | return; | |
327 | index = s->packet_index; | |
328 | ||
31ef9134 CL |
329 | data_blocks = calculate_data_blocks(s); |
330 | syt = calculate_syt(s, cycle); | |
331 | ||
ec00f5e4 | 332 | buffer = s->buffer.packets[index].buffer; |
31ef9134 CL |
333 | buffer[0] = cpu_to_be32(ACCESS_ONCE(s->source_node_id_field) | |
334 | (s->data_block_quadlets << 16) | | |
335 | s->data_block_counter); | |
336 | buffer[1] = cpu_to_be32(CIP_EOH | CIP_FMT_AM | AMDTP_FDF_AM824 | | |
337 | (s->sfc << AMDTP_FDF_SFC_SHIFT) | syt); | |
338 | buffer += 2; | |
339 | ||
340 | pcm = ACCESS_ONCE(s->pcm); | |
341 | if (pcm) | |
342 | s->transfer_samples(s, pcm, buffer, data_blocks); | |
343 | else | |
344 | amdtp_fill_pcm_silence(s, buffer, data_blocks); | |
345 | if (s->midi_ports) | |
346 | amdtp_fill_midi(s, buffer, data_blocks); | |
347 | ||
348 | s->data_block_counter = (s->data_block_counter + data_blocks) & 0xff; | |
349 | ||
350 | packet.payload_length = 8 + data_blocks * 4 * s->data_block_quadlets; | |
ec00f5e4 | 351 | packet.interrupt = IS_ALIGNED(index + 1, INTERRUPT_INTERVAL); |
31ef9134 CL |
352 | packet.skip = 0; |
353 | packet.tag = TAG_CIP; | |
354 | packet.sy = 0; | |
355 | packet.header_length = 0; | |
356 | ||
357 | err = fw_iso_context_queue(s->context, &packet, &s->buffer.iso_buffer, | |
ec00f5e4 CL |
358 | s->buffer.packets[index].offset); |
359 | if (err < 0) { | |
31ef9134 | 360 | dev_err(&s->unit->device, "queueing error: %d\n", err); |
ec00f5e4 CL |
361 | s->packet_index = -1; |
362 | amdtp_out_stream_pcm_abort(s); | |
363 | return; | |
364 | } | |
31ef9134 | 365 | |
ec00f5e4 CL |
366 | if (++index >= QUEUE_LENGTH) |
367 | index = 0; | |
368 | s->packet_index = index; | |
31ef9134 CL |
369 | |
370 | if (pcm) { | |
371 | ptr = s->pcm_buffer_pointer + data_blocks; | |
372 | if (ptr >= pcm->runtime->buffer_size) | |
373 | ptr -= pcm->runtime->buffer_size; | |
374 | ACCESS_ONCE(s->pcm_buffer_pointer) = ptr; | |
375 | ||
376 | s->pcm_period_pointer += data_blocks; | |
377 | if (s->pcm_period_pointer >= pcm->runtime->period_size) { | |
378 | s->pcm_period_pointer -= pcm->runtime->period_size; | |
379 | snd_pcm_period_elapsed(pcm); | |
380 | } | |
381 | } | |
382 | } | |
383 | ||
384 | static void out_packet_callback(struct fw_iso_context *context, u32 cycle, | |
385 | size_t header_length, void *header, void *data) | |
386 | { | |
387 | struct amdtp_out_stream *s = data; | |
388 | unsigned int i, packets = header_length / 4; | |
389 | ||
390 | /* | |
391 | * Compute the cycle of the last queued packet. | |
392 | * (We need only the four lowest bits for the SYT, so we can ignore | |
393 | * that bits 0-11 must wrap around at 3072.) | |
394 | */ | |
395 | cycle += QUEUE_LENGTH - packets; | |
396 | ||
397 | for (i = 0; i < packets; ++i) | |
398 | queue_out_packet(s, ++cycle); | |
399 | } | |
400 | ||
401 | static int queue_initial_skip_packets(struct amdtp_out_stream *s) | |
402 | { | |
403 | struct fw_iso_packet skip_packet = { | |
404 | .skip = 1, | |
405 | }; | |
406 | unsigned int i; | |
407 | int err; | |
408 | ||
409 | for (i = 0; i < QUEUE_LENGTH; ++i) { | |
ec00f5e4 | 410 | skip_packet.interrupt = IS_ALIGNED(s->packet_index + 1, |
31ef9134 CL |
411 | INTERRUPT_INTERVAL); |
412 | err = fw_iso_context_queue(s->context, &skip_packet, NULL, 0); | |
413 | if (err < 0) | |
414 | return err; | |
ec00f5e4 CL |
415 | if (++s->packet_index >= QUEUE_LENGTH) |
416 | s->packet_index = 0; | |
31ef9134 CL |
417 | } |
418 | ||
419 | return 0; | |
420 | } | |
421 | ||
422 | /** | |
423 | * amdtp_out_stream_start - start sending packets | |
424 | * @s: the AMDTP output stream to start | |
425 | * @channel: the isochronous channel on the bus | |
426 | * @speed: firewire speed code | |
427 | * | |
428 | * The stream cannot be started until it has been configured with | |
429 | * amdtp_out_stream_set_hw_params(), amdtp_out_stream_set_pcm(), and | |
430 | * amdtp_out_stream_set_midi(); and it must be started before any | |
431 | * PCM or MIDI device can be started. | |
432 | */ | |
433 | int amdtp_out_stream_start(struct amdtp_out_stream *s, int channel, int speed) | |
434 | { | |
435 | static const struct { | |
436 | unsigned int data_block; | |
437 | unsigned int syt_offset; | |
438 | } initial_state[] = { | |
439 | [CIP_SFC_32000] = { 4, 3072 }, | |
440 | [CIP_SFC_48000] = { 6, 1024 }, | |
441 | [CIP_SFC_96000] = { 12, 1024 }, | |
442 | [CIP_SFC_192000] = { 24, 1024 }, | |
443 | [CIP_SFC_44100] = { 0, 67 }, | |
444 | [CIP_SFC_88200] = { 0, 67 }, | |
445 | [CIP_SFC_176400] = { 0, 67 }, | |
446 | }; | |
447 | int err; | |
448 | ||
449 | mutex_lock(&s->mutex); | |
450 | ||
451 | if (WARN_ON(!IS_ERR(s->context) || | |
452 | (!s->pcm_channels && !s->midi_ports))) { | |
453 | err = -EBADFD; | |
454 | goto err_unlock; | |
455 | } | |
456 | ||
457 | s->data_block_state = initial_state[s->sfc].data_block; | |
458 | s->syt_offset_state = initial_state[s->sfc].syt_offset; | |
459 | s->last_syt_offset = TICKS_PER_CYCLE; | |
460 | ||
461 | err = iso_packets_buffer_init(&s->buffer, s->unit, QUEUE_LENGTH, | |
462 | amdtp_out_stream_get_max_payload(s), | |
463 | DMA_TO_DEVICE); | |
464 | if (err < 0) | |
465 | goto err_unlock; | |
466 | ||
467 | s->context = fw_iso_context_create(fw_parent_device(s->unit)->card, | |
468 | FW_ISO_CONTEXT_TRANSMIT, | |
469 | channel, speed, 0, | |
470 | out_packet_callback, s); | |
471 | if (IS_ERR(s->context)) { | |
472 | err = PTR_ERR(s->context); | |
473 | if (err == -EBUSY) | |
474 | dev_err(&s->unit->device, | |
475 | "no free output stream on this controller\n"); | |
476 | goto err_buffer; | |
477 | } | |
478 | ||
479 | amdtp_out_stream_update(s); | |
480 | ||
ec00f5e4 | 481 | s->packet_index = 0; |
31ef9134 CL |
482 | s->data_block_counter = 0; |
483 | err = queue_initial_skip_packets(s); | |
484 | if (err < 0) | |
485 | goto err_context; | |
486 | ||
487 | err = fw_iso_context_start(s->context, -1, 0, 0); | |
488 | if (err < 0) | |
489 | goto err_context; | |
490 | ||
491 | mutex_unlock(&s->mutex); | |
492 | ||
493 | return 0; | |
494 | ||
495 | err_context: | |
496 | fw_iso_context_destroy(s->context); | |
497 | s->context = ERR_PTR(-1); | |
498 | err_buffer: | |
499 | iso_packets_buffer_destroy(&s->buffer, s->unit); | |
500 | err_unlock: | |
501 | mutex_unlock(&s->mutex); | |
502 | ||
503 | return err; | |
504 | } | |
505 | EXPORT_SYMBOL(amdtp_out_stream_start); | |
506 | ||
507 | /** | |
508 | * amdtp_out_stream_update - update the stream after a bus reset | |
509 | * @s: the AMDTP output stream | |
510 | */ | |
511 | void amdtp_out_stream_update(struct amdtp_out_stream *s) | |
512 | { | |
513 | ACCESS_ONCE(s->source_node_id_field) = | |
514 | (fw_parent_device(s->unit)->card->node_id & 0x3f) << 24; | |
515 | } | |
516 | EXPORT_SYMBOL(amdtp_out_stream_update); | |
517 | ||
518 | /** | |
519 | * amdtp_out_stream_stop - stop sending packets | |
520 | * @s: the AMDTP output stream to stop | |
521 | * | |
522 | * All PCM and MIDI devices of the stream must be stopped before the stream | |
523 | * itself can be stopped. | |
524 | */ | |
525 | void amdtp_out_stream_stop(struct amdtp_out_stream *s) | |
526 | { | |
527 | mutex_lock(&s->mutex); | |
528 | ||
529 | if (IS_ERR(s->context)) { | |
530 | mutex_unlock(&s->mutex); | |
531 | return; | |
532 | } | |
533 | ||
534 | fw_iso_context_stop(s->context); | |
535 | fw_iso_context_destroy(s->context); | |
536 | s->context = ERR_PTR(-1); | |
537 | iso_packets_buffer_destroy(&s->buffer, s->unit); | |
538 | ||
539 | mutex_unlock(&s->mutex); | |
540 | } | |
541 | EXPORT_SYMBOL(amdtp_out_stream_stop); | |
542 | ||
543 | /** | |
544 | * amdtp_out_stream_pcm_abort - abort the running PCM device | |
545 | * @s: the AMDTP stream about to be stopped | |
546 | * | |
547 | * If the isochronous stream needs to be stopped asynchronously, call this | |
548 | * function first to stop the PCM device. | |
549 | */ | |
550 | void amdtp_out_stream_pcm_abort(struct amdtp_out_stream *s) | |
551 | { | |
552 | struct snd_pcm_substream *pcm; | |
553 | ||
554 | pcm = ACCESS_ONCE(s->pcm); | |
555 | if (pcm) { | |
556 | snd_pcm_stream_lock_irq(pcm); | |
557 | if (snd_pcm_running(pcm)) | |
558 | snd_pcm_stop(pcm, SNDRV_PCM_STATE_XRUN); | |
559 | snd_pcm_stream_unlock_irq(pcm); | |
560 | } | |
561 | } | |
562 | EXPORT_SYMBOL(amdtp_out_stream_pcm_abort); |