2 * Audio and Music Data Transmission Protocol (IEC 61883-6) streams
3 * with Common Isochronous Packet (IEC 61883-1) headers
5 * Copyright (c) Clemens Ladisch <clemens@ladisch.de>
6 * Licensed under the terms of the GNU General Public License, version 2.
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 <linux/sched.h>
15 #include <sound/pcm.h>
16 #include <sound/pcm_params.h>
17 #include <sound/rawmidi.h>
20 #define TICKS_PER_CYCLE 3072
21 #define CYCLES_PER_SECOND 8000
22 #define TICKS_PER_SECOND (TICKS_PER_CYCLE * CYCLES_PER_SECOND)
24 #define TRANSFER_DELAY_TICKS 0x2e00 /* 479.17 µs */
26 /* isochronous header parameters */
27 #define ISO_DATA_LENGTH_SHIFT 16
30 /* common isochronous packet header parameters */
31 #define CIP_EOH (1u << 31)
32 #define CIP_EOH_MASK 0x80000000
33 #define CIP_FMT_AM (0x10 << 24)
34 #define CIP_FMT_MASK 0x3f000000
35 #define CIP_SYT_MASK 0x0000ffff
36 #define CIP_SYT_NO_INFO 0xffff
37 #define CIP_FDF_MASK 0x00ff0000
38 #define CIP_FDF_SFC_SHIFT 16
41 * Audio and Music transfer protocol specific parameters
42 * only "Clock-based rate control mode" is supported
44 #define AMDTP_FDF_AM824 (0 << (CIP_FDF_SFC_SHIFT + 3))
45 #define AMDTP_FDF_NO_DATA 0xff
46 #define AMDTP_DBS_MASK 0x00ff0000
47 #define AMDTP_DBS_SHIFT 16
48 #define AMDTP_DBC_MASK 0x000000ff
50 /* TODO: make these configurable */
51 #define INTERRUPT_INTERVAL 16
52 #define QUEUE_LENGTH 48
54 #define IN_PACKET_HEADER_SIZE 4
55 #define OUT_PACKET_HEADER_SIZE 0
57 static void pcm_period_tasklet(unsigned long data);
60 * amdtp_stream_init - initialize an AMDTP stream structure
61 * @s: the AMDTP stream to initialize
62 * @unit: the target of the stream
63 * @dir: the direction of stream
64 * @flags: the packet transmission method to use
66 int amdtp_stream_init(struct amdtp_stream *s, struct fw_unit *unit,
67 enum amdtp_stream_direction dir, enum cip_flags flags)
69 s->unit = fw_unit_get(unit);
72 s->context = ERR_PTR(-1);
73 mutex_init(&s->mutex);
74 tasklet_init(&s->period_tasklet, pcm_period_tasklet, (unsigned long)s);
77 init_waitqueue_head(&s->callback_wait);
78 s->callbacked = false;
83 EXPORT_SYMBOL(amdtp_stream_init);
86 * amdtp_stream_destroy - free stream resources
87 * @s: the AMDTP stream to destroy
89 void amdtp_stream_destroy(struct amdtp_stream *s)
91 WARN_ON(amdtp_stream_running(s));
92 mutex_destroy(&s->mutex);
95 EXPORT_SYMBOL(amdtp_stream_destroy);
97 const unsigned int amdtp_syt_intervals[CIP_SFC_COUNT] = {
101 [CIP_SFC_88200] = 16,
102 [CIP_SFC_96000] = 16,
103 [CIP_SFC_176400] = 32,
104 [CIP_SFC_192000] = 32,
106 EXPORT_SYMBOL(amdtp_syt_intervals);
109 * amdtp_stream_add_pcm_hw_constraints - add hw constraints for PCM substream
110 * @s: the AMDTP stream, which must be initialized.
111 * @runtime: the PCM substream runtime
113 int amdtp_stream_add_pcm_hw_constraints(struct amdtp_stream *s,
114 struct snd_pcm_runtime *runtime)
118 /* AM824 in IEC 61883-6 can deliver 24bit data */
119 err = snd_pcm_hw_constraint_msbits(runtime, 0, 32, 24);
124 * Currently firewire-lib processes 16 packets in one software
125 * interrupt callback. This equals to 2msec but actually the
126 * interval of the interrupts has a jitter.
127 * Additionally, even if adding a constraint to fit period size to
128 * 2msec, actual calculated frames per period doesn't equal to 2msec,
129 * depending on sampling rate.
130 * Anyway, the interval to call snd_pcm_period_elapsed() cannot 2msec.
131 * Here let us use 5msec for safe period interrupt.
133 err = snd_pcm_hw_constraint_minmax(runtime,
134 SNDRV_PCM_HW_PARAM_PERIOD_TIME,
139 /* Non-Blocking stream has no more constraints */
140 if (!(s->flags & CIP_BLOCKING))
144 * One AMDTP packet can include some frames. In blocking mode, the
145 * number equals to SYT_INTERVAL. So the number is 8, 16 or 32,
146 * depending on its sampling rate. For accurate period interrupt, it's
147 * preferrable to aligh period/buffer sizes to current SYT_INTERVAL.
149 * TODO: These constraints can be improved with propper rules.
150 * Currently apply LCM of SYT_INTEVALs.
152 err = snd_pcm_hw_constraint_step(runtime, 0,
153 SNDRV_PCM_HW_PARAM_PERIOD_SIZE, 32);
156 err = snd_pcm_hw_constraint_step(runtime, 0,
157 SNDRV_PCM_HW_PARAM_BUFFER_SIZE, 32);
161 EXPORT_SYMBOL(amdtp_stream_add_pcm_hw_constraints);
164 * amdtp_stream_set_parameters - set stream parameters
165 * @s: the AMDTP stream to configure
166 * @rate: the sample rate
167 * @pcm_channels: the number of PCM samples in each data block, to be encoded
168 * as AM824 multi-bit linear audio
169 * @midi_ports: the number of MIDI ports (i.e., MPX-MIDI Data Channels)
171 * The parameters must be set before the stream is started, and must not be
172 * changed while the stream is running.
174 void amdtp_stream_set_parameters(struct amdtp_stream *s,
176 unsigned int pcm_channels,
177 unsigned int midi_ports)
179 static const unsigned int rates[] = {
180 [CIP_SFC_32000] = 32000,
181 [CIP_SFC_44100] = 44100,
182 [CIP_SFC_48000] = 48000,
183 [CIP_SFC_88200] = 88200,
184 [CIP_SFC_96000] = 96000,
185 [CIP_SFC_176400] = 176400,
186 [CIP_SFC_192000] = 192000,
188 unsigned int i, sfc, midi_channels;
190 midi_channels = DIV_ROUND_UP(midi_ports, 8);
192 if (WARN_ON(amdtp_stream_running(s)) |
193 WARN_ON(pcm_channels > AMDTP_MAX_CHANNELS_FOR_PCM) |
194 WARN_ON(midi_channels > AMDTP_MAX_CHANNELS_FOR_MIDI))
197 for (sfc = 0; sfc < CIP_SFC_COUNT; ++sfc)
198 if (rates[sfc] == rate)
204 s->pcm_channels = pcm_channels;
206 s->data_block_quadlets = s->pcm_channels + midi_channels;
207 s->midi_ports = midi_ports;
209 s->syt_interval = amdtp_syt_intervals[sfc];
211 /* default buffering in the device */
212 s->transfer_delay = TRANSFER_DELAY_TICKS - TICKS_PER_CYCLE;
213 if (s->flags & CIP_BLOCKING)
214 /* additional buffering needed to adjust for no-data packets */
215 s->transfer_delay += TICKS_PER_SECOND * s->syt_interval / rate;
217 /* init the position map for PCM and MIDI channels */
218 for (i = 0; i < pcm_channels; i++)
219 s->pcm_positions[i] = i;
220 s->midi_position = s->pcm_channels;
222 EXPORT_SYMBOL(amdtp_stream_set_parameters);
225 * amdtp_stream_get_max_payload - get the stream's packet size
226 * @s: the AMDTP stream
228 * This function must not be called before the stream has been configured
229 * with amdtp_stream_set_parameters().
231 unsigned int amdtp_stream_get_max_payload(struct amdtp_stream *s)
233 return 8 + s->syt_interval * s->data_block_quadlets * 4;
235 EXPORT_SYMBOL(amdtp_stream_get_max_payload);
237 static void amdtp_write_s16(struct amdtp_stream *s,
238 struct snd_pcm_substream *pcm,
239 __be32 *buffer, unsigned int frames);
240 static void amdtp_write_s32(struct amdtp_stream *s,
241 struct snd_pcm_substream *pcm,
242 __be32 *buffer, unsigned int frames);
243 static void amdtp_read_s32(struct amdtp_stream *s,
244 struct snd_pcm_substream *pcm,
245 __be32 *buffer, unsigned int frames);
248 * amdtp_stream_set_pcm_format - set the PCM format
249 * @s: the AMDTP stream to configure
250 * @format: the format of the ALSA PCM device
252 * The sample format must be set after the other paramters (rate/PCM channels/
253 * MIDI) and before the stream is started, and must not be changed while the
256 void amdtp_stream_set_pcm_format(struct amdtp_stream *s,
257 snd_pcm_format_t format)
259 if (WARN_ON(amdtp_stream_pcm_running(s)))
266 case SNDRV_PCM_FORMAT_S16:
267 if (s->direction == AMDTP_OUT_STREAM) {
268 s->transfer_samples = amdtp_write_s16;
273 case SNDRV_PCM_FORMAT_S32:
274 if (s->direction == AMDTP_OUT_STREAM)
275 s->transfer_samples = amdtp_write_s32;
277 s->transfer_samples = amdtp_read_s32;
281 EXPORT_SYMBOL(amdtp_stream_set_pcm_format);
284 * amdtp_stream_pcm_prepare - prepare PCM device for running
285 * @s: the AMDTP stream
287 * This function should be called from the PCM device's .prepare callback.
289 void amdtp_stream_pcm_prepare(struct amdtp_stream *s)
291 tasklet_kill(&s->period_tasklet);
292 s->pcm_buffer_pointer = 0;
293 s->pcm_period_pointer = 0;
294 s->pointer_flush = true;
296 EXPORT_SYMBOL(amdtp_stream_pcm_prepare);
298 static unsigned int calculate_data_blocks(struct amdtp_stream *s)
300 unsigned int phase, data_blocks;
302 if (s->flags & CIP_BLOCKING)
303 data_blocks = s->syt_interval;
304 else if (!cip_sfc_is_base_44100(s->sfc)) {
305 /* Sample_rate / 8000 is an integer, and precomputed. */
306 data_blocks = s->data_block_state;
308 phase = s->data_block_state;
311 * This calculates the number of data blocks per packet so that
312 * 1) the overall rate is correct and exactly synchronized to
314 * 2) packets with a rounded-up number of blocks occur as early
315 * as possible in the sequence (to prevent underruns of the
318 if (s->sfc == CIP_SFC_44100)
319 /* 6 6 5 6 5 6 5 ... */
320 data_blocks = 5 + ((phase & 1) ^
321 (phase == 0 || phase >= 40));
323 /* 12 11 11 11 11 ... or 23 22 22 22 22 ... */
324 data_blocks = 11 * (s->sfc >> 1) + (phase == 0);
325 if (++phase >= (80 >> (s->sfc >> 1)))
327 s->data_block_state = phase;
333 static unsigned int calculate_syt(struct amdtp_stream *s,
336 unsigned int syt_offset, phase, index, syt;
338 if (s->last_syt_offset < TICKS_PER_CYCLE) {
339 if (!cip_sfc_is_base_44100(s->sfc))
340 syt_offset = s->last_syt_offset + s->syt_offset_state;
343 * The time, in ticks, of the n'th SYT_INTERVAL sample is:
344 * n * SYT_INTERVAL * 24576000 / sample_rate
345 * Modulo TICKS_PER_CYCLE, the difference between successive
346 * elements is about 1386.23. Rounding the results of this
347 * formula to the SYT precision results in a sequence of
348 * differences that begins with:
349 * 1386 1386 1387 1386 1386 1386 1387 1386 1386 1386 1387 ...
350 * This code generates _exactly_ the same sequence.
352 phase = s->syt_offset_state;
354 syt_offset = s->last_syt_offset;
355 syt_offset += 1386 + ((index && !(index & 3)) ||
359 s->syt_offset_state = phase;
362 syt_offset = s->last_syt_offset - TICKS_PER_CYCLE;
363 s->last_syt_offset = syt_offset;
365 if (syt_offset < TICKS_PER_CYCLE) {
366 syt_offset += s->transfer_delay;
367 syt = (cycle + syt_offset / TICKS_PER_CYCLE) << 12;
368 syt += syt_offset % TICKS_PER_CYCLE;
370 return syt & CIP_SYT_MASK;
372 return CIP_SYT_NO_INFO;
376 static void amdtp_write_s32(struct amdtp_stream *s,
377 struct snd_pcm_substream *pcm,
378 __be32 *buffer, unsigned int frames)
380 struct snd_pcm_runtime *runtime = pcm->runtime;
381 unsigned int channels, remaining_frames, i, c;
384 channels = s->pcm_channels;
385 src = (void *)runtime->dma_area +
386 frames_to_bytes(runtime, s->pcm_buffer_pointer);
387 remaining_frames = runtime->buffer_size - s->pcm_buffer_pointer;
389 for (i = 0; i < frames; ++i) {
390 for (c = 0; c < channels; ++c) {
391 buffer[s->pcm_positions[c]] =
392 cpu_to_be32((*src >> 8) | 0x40000000);
395 buffer += s->data_block_quadlets;
396 if (--remaining_frames == 0)
397 src = (void *)runtime->dma_area;
401 static void amdtp_write_s16(struct amdtp_stream *s,
402 struct snd_pcm_substream *pcm,
403 __be32 *buffer, unsigned int frames)
405 struct snd_pcm_runtime *runtime = pcm->runtime;
406 unsigned int channels, remaining_frames, i, c;
409 channels = s->pcm_channels;
410 src = (void *)runtime->dma_area +
411 frames_to_bytes(runtime, s->pcm_buffer_pointer);
412 remaining_frames = runtime->buffer_size - s->pcm_buffer_pointer;
414 for (i = 0; i < frames; ++i) {
415 for (c = 0; c < channels; ++c) {
416 buffer[s->pcm_positions[c]] =
417 cpu_to_be32((*src << 8) | 0x40000000);
420 buffer += s->data_block_quadlets;
421 if (--remaining_frames == 0)
422 src = (void *)runtime->dma_area;
426 static void amdtp_read_s32(struct amdtp_stream *s,
427 struct snd_pcm_substream *pcm,
428 __be32 *buffer, unsigned int frames)
430 struct snd_pcm_runtime *runtime = pcm->runtime;
431 unsigned int channels, remaining_frames, i, c;
434 channels = s->pcm_channels;
435 dst = (void *)runtime->dma_area +
436 frames_to_bytes(runtime, s->pcm_buffer_pointer);
437 remaining_frames = runtime->buffer_size - s->pcm_buffer_pointer;
439 for (i = 0; i < frames; ++i) {
440 for (c = 0; c < channels; ++c) {
441 *dst = be32_to_cpu(buffer[s->pcm_positions[c]]) << 8;
444 buffer += s->data_block_quadlets;
445 if (--remaining_frames == 0)
446 dst = (void *)runtime->dma_area;
450 static void amdtp_fill_pcm_silence(struct amdtp_stream *s,
451 __be32 *buffer, unsigned int frames)
455 for (i = 0; i < frames; ++i) {
456 for (c = 0; c < s->pcm_channels; ++c)
457 buffer[s->pcm_positions[c]] = cpu_to_be32(0x40000000);
458 buffer += s->data_block_quadlets;
462 static void amdtp_fill_midi(struct amdtp_stream *s,
463 __be32 *buffer, unsigned int frames)
465 unsigned int f, port;
468 for (f = 0; f < frames; f++) {
469 buffer[s->midi_position] = 0;
470 b = (u8 *)&buffer[s->midi_position];
472 port = (s->data_block_counter + f) % 8;
473 if ((s->midi[port] == NULL) ||
474 (snd_rawmidi_transmit(s->midi[port], b + 1, 1) <= 0))
479 buffer += s->data_block_quadlets;
483 static void amdtp_pull_midi(struct amdtp_stream *s,
484 __be32 *buffer, unsigned int frames)
486 unsigned int f, port;
490 for (f = 0; f < frames; f++) {
491 port = (s->data_block_counter + f) % 8;
492 b = (u8 *)&buffer[s->midi_position];
495 if ((1 <= len) && (len <= 3) && (s->midi[port]))
496 snd_rawmidi_receive(s->midi[port], b + 1, len);
498 buffer += s->data_block_quadlets;
502 static void update_pcm_pointers(struct amdtp_stream *s,
503 struct snd_pcm_substream *pcm,
507 ptr = s->pcm_buffer_pointer + frames;
508 if (ptr >= pcm->runtime->buffer_size)
509 ptr -= pcm->runtime->buffer_size;
510 ACCESS_ONCE(s->pcm_buffer_pointer) = ptr;
512 s->pcm_period_pointer += frames;
513 if (s->pcm_period_pointer >= pcm->runtime->period_size) {
514 s->pcm_period_pointer -= pcm->runtime->period_size;
515 s->pointer_flush = false;
516 tasklet_hi_schedule(&s->period_tasklet);
520 static void pcm_period_tasklet(unsigned long data)
522 struct amdtp_stream *s = (void *)data;
523 struct snd_pcm_substream *pcm = ACCESS_ONCE(s->pcm);
526 snd_pcm_period_elapsed(pcm);
529 static int queue_packet(struct amdtp_stream *s,
530 unsigned int header_length,
531 unsigned int payload_length, bool skip)
533 struct fw_iso_packet p = {0};
536 if (IS_ERR(s->context))
539 p.interrupt = IS_ALIGNED(s->packet_index + 1, INTERRUPT_INTERVAL);
541 p.header_length = header_length;
542 p.payload_length = (!skip) ? payload_length : 0;
544 err = fw_iso_context_queue(s->context, &p, &s->buffer.iso_buffer,
545 s->buffer.packets[s->packet_index].offset);
547 dev_err(&s->unit->device, "queueing error: %d\n", err);
551 if (++s->packet_index >= QUEUE_LENGTH)
557 static inline int queue_out_packet(struct amdtp_stream *s,
558 unsigned int payload_length, bool skip)
560 return queue_packet(s, OUT_PACKET_HEADER_SIZE,
561 payload_length, skip);
564 static inline int queue_in_packet(struct amdtp_stream *s)
566 return queue_packet(s, IN_PACKET_HEADER_SIZE,
567 amdtp_stream_get_max_payload(s), false);
570 static void handle_out_packet(struct amdtp_stream *s, unsigned int syt)
573 unsigned int data_blocks, payload_length;
574 struct snd_pcm_substream *pcm;
576 if (s->packet_index < 0)
579 /* this module generate empty packet for 'no data' */
580 if (!(s->flags & CIP_BLOCKING) || (syt != CIP_SYT_NO_INFO))
581 data_blocks = calculate_data_blocks(s);
585 buffer = s->buffer.packets[s->packet_index].buffer;
586 buffer[0] = cpu_to_be32(ACCESS_ONCE(s->source_node_id_field) |
587 (s->data_block_quadlets << AMDTP_DBS_SHIFT) |
588 s->data_block_counter);
589 buffer[1] = cpu_to_be32(CIP_EOH | CIP_FMT_AM | AMDTP_FDF_AM824 |
590 (s->sfc << CIP_FDF_SFC_SHIFT) | syt);
593 pcm = ACCESS_ONCE(s->pcm);
595 s->transfer_samples(s, pcm, buffer, data_blocks);
597 amdtp_fill_pcm_silence(s, buffer, data_blocks);
599 amdtp_fill_midi(s, buffer, data_blocks);
601 s->data_block_counter = (s->data_block_counter + data_blocks) & 0xff;
603 payload_length = 8 + data_blocks * 4 * s->data_block_quadlets;
604 if (queue_out_packet(s, payload_length, false) < 0) {
605 s->packet_index = -1;
606 amdtp_stream_pcm_abort(s);
611 update_pcm_pointers(s, pcm, data_blocks);
614 static void handle_in_packet(struct amdtp_stream *s,
615 unsigned int payload_quadlets,
619 unsigned int data_blocks, data_block_quadlets, data_block_counter;
620 struct snd_pcm_substream *pcm = NULL;
622 cip_header[0] = be32_to_cpu(buffer[0]);
623 cip_header[1] = be32_to_cpu(buffer[1]);
626 * This module supports 'Two-quadlet CIP header with SYT field'.
627 * For convenience, also check FMT field is AM824 or not.
629 if (((cip_header[0] & CIP_EOH_MASK) == CIP_EOH) ||
630 ((cip_header[1] & CIP_EOH_MASK) != CIP_EOH) ||
631 ((cip_header[1] & CIP_FMT_MASK) != CIP_FMT_AM)) {
632 dev_info_ratelimited(&s->unit->device,
633 "Invalid CIP header for AMDTP: %08X:%08X\n",
634 cip_header[0], cip_header[1]);
638 /* Calculate data blocks */
639 if (payload_quadlets < 3 ||
640 ((cip_header[1] & CIP_FDF_MASK) ==
641 (AMDTP_FDF_NO_DATA << CIP_FDF_SFC_SHIFT))) {
644 data_block_quadlets =
645 (cip_header[0] & AMDTP_DBS_MASK) >> AMDTP_DBS_SHIFT;
646 /* avoid division by zero */
647 if (data_block_quadlets == 0) {
648 dev_info_ratelimited(&s->unit->device,
649 "Detect invalid value in dbs field: %08X\n",
654 data_blocks = (payload_quadlets - 2) / data_block_quadlets;
657 /* Check data block counter continuity */
658 data_block_counter = cip_header[0] & AMDTP_DBC_MASK;
659 if (data_block_counter != s->data_block_counter) {
660 dev_info(&s->unit->device,
661 "Detect discontinuity of CIP: %02X %02X\n",
662 s->data_block_counter, data_block_counter);
666 if (data_blocks > 0) {
669 pcm = ACCESS_ONCE(s->pcm);
671 s->transfer_samples(s, pcm, buffer, data_blocks);
674 amdtp_pull_midi(s, buffer, data_blocks);
677 s->data_block_counter = (data_block_counter + data_blocks) & 0xff;
679 if (queue_in_packet(s) < 0)
683 update_pcm_pointers(s, pcm, data_blocks);
687 s->packet_index = -1;
688 amdtp_stream_pcm_abort(s);
691 static void out_stream_callback(struct fw_iso_context *context, u32 cycle,
692 size_t header_length, void *header,
695 struct amdtp_stream *s = private_data;
696 unsigned int i, syt, packets = header_length / 4;
699 * Compute the cycle of the last queued packet.
700 * (We need only the four lowest bits for the SYT, so we can ignore
701 * that bits 0-11 must wrap around at 3072.)
703 cycle += QUEUE_LENGTH - packets;
705 for (i = 0; i < packets; ++i) {
706 syt = calculate_syt(s, ++cycle);
707 handle_out_packet(s, syt);
709 fw_iso_context_queue_flush(s->context);
712 static void in_stream_callback(struct fw_iso_context *context, u32 cycle,
713 size_t header_length, void *header,
716 struct amdtp_stream *s = private_data;
717 unsigned int p, syt, packets, payload_quadlets;
718 __be32 *buffer, *headers = header;
720 /* The number of packets in buffer */
721 packets = header_length / IN_PACKET_HEADER_SIZE;
723 for (p = 0; p < packets; p++) {
724 if (s->packet_index < 0)
727 buffer = s->buffer.packets[s->packet_index].buffer;
729 /* Process sync slave stream */
730 if (s->sync_slave && s->sync_slave->callbacked) {
731 syt = be32_to_cpu(buffer[1]) & CIP_SYT_MASK;
732 handle_out_packet(s->sync_slave, syt);
735 /* The number of quadlets in this packet */
737 (be32_to_cpu(headers[p]) >> ISO_DATA_LENGTH_SHIFT) / 4;
738 handle_in_packet(s, payload_quadlets, buffer);
741 /* Queueing error or detecting discontinuity */
742 if (s->packet_index < 0) {
743 /* Abort sync slave. */
745 s->sync_slave->packet_index = -1;
746 amdtp_stream_pcm_abort(s->sync_slave);
751 /* when sync to device, flush the packets for slave stream */
752 if (s->sync_slave && s->sync_slave->callbacked)
753 fw_iso_context_queue_flush(s->sync_slave->context);
755 fw_iso_context_queue_flush(s->context);
758 /* processing is done by master callback */
759 static void slave_stream_callback(struct fw_iso_context *context, u32 cycle,
760 size_t header_length, void *header,
766 /* this is executed one time */
767 static void amdtp_stream_first_callback(struct fw_iso_context *context,
768 u32 cycle, size_t header_length,
769 void *header, void *private_data)
771 struct amdtp_stream *s = private_data;
774 * For in-stream, first packet has come.
775 * For out-stream, prepared to transmit first packet
777 s->callbacked = true;
778 wake_up(&s->callback_wait);
780 if (s->direction == AMDTP_IN_STREAM)
781 context->callback.sc = in_stream_callback;
782 else if ((s->flags & CIP_BLOCKING) && (s->flags & CIP_SYNC_TO_DEVICE))
783 context->callback.sc = slave_stream_callback;
785 context->callback.sc = out_stream_callback;
787 context->callback.sc(context, cycle, header_length, header, s);
791 * amdtp_stream_start - start transferring packets
792 * @s: the AMDTP stream to start
793 * @channel: the isochronous channel on the bus
794 * @speed: firewire speed code
796 * The stream cannot be started until it has been configured with
797 * amdtp_stream_set_parameters() and it must be started before any PCM or MIDI
798 * device can be started.
800 int amdtp_stream_start(struct amdtp_stream *s, int channel, int speed)
802 static const struct {
803 unsigned int data_block;
804 unsigned int syt_offset;
805 } initial_state[] = {
806 [CIP_SFC_32000] = { 4, 3072 },
807 [CIP_SFC_48000] = { 6, 1024 },
808 [CIP_SFC_96000] = { 12, 1024 },
809 [CIP_SFC_192000] = { 24, 1024 },
810 [CIP_SFC_44100] = { 0, 67 },
811 [CIP_SFC_88200] = { 0, 67 },
812 [CIP_SFC_176400] = { 0, 67 },
814 unsigned int header_size;
815 enum dma_data_direction dir;
818 mutex_lock(&s->mutex);
820 if (WARN_ON(amdtp_stream_running(s) ||
821 (s->data_block_quadlets < 1))) {
826 s->data_block_counter = 0;
827 s->data_block_state = initial_state[s->sfc].data_block;
828 s->syt_offset_state = initial_state[s->sfc].syt_offset;
829 s->last_syt_offset = TICKS_PER_CYCLE;
831 /* initialize packet buffer */
832 if (s->direction == AMDTP_IN_STREAM) {
833 dir = DMA_FROM_DEVICE;
834 type = FW_ISO_CONTEXT_RECEIVE;
835 header_size = IN_PACKET_HEADER_SIZE;
838 type = FW_ISO_CONTEXT_TRANSMIT;
839 header_size = OUT_PACKET_HEADER_SIZE;
841 err = iso_packets_buffer_init(&s->buffer, s->unit, QUEUE_LENGTH,
842 amdtp_stream_get_max_payload(s), dir);
846 s->context = fw_iso_context_create(fw_parent_device(s->unit)->card,
847 type, channel, speed, header_size,
848 amdtp_stream_first_callback, s);
849 if (IS_ERR(s->context)) {
850 err = PTR_ERR(s->context);
852 dev_err(&s->unit->device,
853 "no free stream on this controller\n");
857 amdtp_stream_update(s);
861 if (s->direction == AMDTP_IN_STREAM)
862 err = queue_in_packet(s);
864 err = queue_out_packet(s, 0, true);
867 } while (s->packet_index > 0);
869 /* NOTE: TAG1 matches CIP. This just affects in stream. */
870 s->callbacked = false;
871 err = fw_iso_context_start(s->context, -1, 0,
872 FW_ISO_CONTEXT_MATCH_TAG1);
876 mutex_unlock(&s->mutex);
881 fw_iso_context_destroy(s->context);
882 s->context = ERR_PTR(-1);
884 iso_packets_buffer_destroy(&s->buffer, s->unit);
886 mutex_unlock(&s->mutex);
890 EXPORT_SYMBOL(amdtp_stream_start);
893 * amdtp_stream_pcm_pointer - get the PCM buffer position
894 * @s: the AMDTP stream that transports the PCM data
896 * Returns the current buffer position, in frames.
898 unsigned long amdtp_stream_pcm_pointer(struct amdtp_stream *s)
900 /* this optimization is allowed to be racy */
901 if (s->pointer_flush && amdtp_stream_running(s))
902 fw_iso_context_flush_completions(s->context);
904 s->pointer_flush = true;
906 return ACCESS_ONCE(s->pcm_buffer_pointer);
908 EXPORT_SYMBOL(amdtp_stream_pcm_pointer);
911 * amdtp_stream_update - update the stream after a bus reset
912 * @s: the AMDTP stream
914 void amdtp_stream_update(struct amdtp_stream *s)
916 ACCESS_ONCE(s->source_node_id_field) =
917 (fw_parent_device(s->unit)->card->node_id & 0x3f) << 24;
919 EXPORT_SYMBOL(amdtp_stream_update);
922 * amdtp_stream_stop - stop sending packets
923 * @s: the AMDTP stream to stop
925 * All PCM and MIDI devices of the stream must be stopped before the stream
926 * itself can be stopped.
928 void amdtp_stream_stop(struct amdtp_stream *s)
930 mutex_lock(&s->mutex);
932 if (!amdtp_stream_running(s)) {
933 mutex_unlock(&s->mutex);
937 tasklet_kill(&s->period_tasklet);
938 fw_iso_context_stop(s->context);
939 fw_iso_context_destroy(s->context);
940 s->context = ERR_PTR(-1);
941 iso_packets_buffer_destroy(&s->buffer, s->unit);
943 s->callbacked = false;
945 mutex_unlock(&s->mutex);
947 EXPORT_SYMBOL(amdtp_stream_stop);
950 * amdtp_stream_pcm_abort - abort the running PCM device
951 * @s: the AMDTP stream about to be stopped
953 * If the isochronous stream needs to be stopped asynchronously, call this
954 * function first to stop the PCM device.
956 void amdtp_stream_pcm_abort(struct amdtp_stream *s)
958 struct snd_pcm_substream *pcm;
960 pcm = ACCESS_ONCE(s->pcm);
962 snd_pcm_stream_lock_irq(pcm);
963 if (snd_pcm_running(pcm))
964 snd_pcm_stop(pcm, SNDRV_PCM_STATE_XRUN);
965 snd_pcm_stream_unlock_irq(pcm);
968 EXPORT_SYMBOL(amdtp_stream_pcm_abort);