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;
81 s->rx_blocks_for_midi = UINT_MAX;
85 EXPORT_SYMBOL(amdtp_stream_init);
88 * amdtp_stream_destroy - free stream resources
89 * @s: the AMDTP stream to destroy
91 void amdtp_stream_destroy(struct amdtp_stream *s)
93 WARN_ON(amdtp_stream_running(s));
94 mutex_destroy(&s->mutex);
97 EXPORT_SYMBOL(amdtp_stream_destroy);
99 const unsigned int amdtp_syt_intervals[CIP_SFC_COUNT] = {
103 [CIP_SFC_88200] = 16,
104 [CIP_SFC_96000] = 16,
105 [CIP_SFC_176400] = 32,
106 [CIP_SFC_192000] = 32,
108 EXPORT_SYMBOL(amdtp_syt_intervals);
110 const unsigned int amdtp_rate_table[CIP_SFC_COUNT] = {
111 [CIP_SFC_32000] = 32000,
112 [CIP_SFC_44100] = 44100,
113 [CIP_SFC_48000] = 48000,
114 [CIP_SFC_88200] = 88200,
115 [CIP_SFC_96000] = 96000,
116 [CIP_SFC_176400] = 176400,
117 [CIP_SFC_192000] = 192000,
119 EXPORT_SYMBOL(amdtp_rate_table);
122 * amdtp_stream_add_pcm_hw_constraints - add hw constraints for PCM substream
123 * @s: the AMDTP stream, which must be initialized.
124 * @runtime: the PCM substream runtime
126 int amdtp_stream_add_pcm_hw_constraints(struct amdtp_stream *s,
127 struct snd_pcm_runtime *runtime)
131 /* AM824 in IEC 61883-6 can deliver 24bit data */
132 err = snd_pcm_hw_constraint_msbits(runtime, 0, 32, 24);
137 * Currently firewire-lib processes 16 packets in one software
138 * interrupt callback. This equals to 2msec but actually the
139 * interval of the interrupts has a jitter.
140 * Additionally, even if adding a constraint to fit period size to
141 * 2msec, actual calculated frames per period doesn't equal to 2msec,
142 * depending on sampling rate.
143 * Anyway, the interval to call snd_pcm_period_elapsed() cannot 2msec.
144 * Here let us use 5msec for safe period interrupt.
146 err = snd_pcm_hw_constraint_minmax(runtime,
147 SNDRV_PCM_HW_PARAM_PERIOD_TIME,
152 /* Non-Blocking stream has no more constraints */
153 if (!(s->flags & CIP_BLOCKING))
157 * One AMDTP packet can include some frames. In blocking mode, the
158 * number equals to SYT_INTERVAL. So the number is 8, 16 or 32,
159 * depending on its sampling rate. For accurate period interrupt, it's
160 * preferrable to aligh period/buffer sizes to current SYT_INTERVAL.
162 * TODO: These constraints can be improved with propper rules.
163 * Currently apply LCM of SYT_INTEVALs.
165 err = snd_pcm_hw_constraint_step(runtime, 0,
166 SNDRV_PCM_HW_PARAM_PERIOD_SIZE, 32);
169 err = snd_pcm_hw_constraint_step(runtime, 0,
170 SNDRV_PCM_HW_PARAM_BUFFER_SIZE, 32);
174 EXPORT_SYMBOL(amdtp_stream_add_pcm_hw_constraints);
177 * amdtp_stream_set_parameters - set stream parameters
178 * @s: the AMDTP stream to configure
179 * @rate: the sample rate
180 * @pcm_channels: the number of PCM samples in each data block, to be encoded
181 * as AM824 multi-bit linear audio
182 * @midi_ports: the number of MIDI ports (i.e., MPX-MIDI Data Channels)
184 * The parameters must be set before the stream is started, and must not be
185 * changed while the stream is running.
187 void amdtp_stream_set_parameters(struct amdtp_stream *s,
189 unsigned int pcm_channels,
190 unsigned int midi_ports)
192 unsigned int i, sfc, midi_channels;
194 midi_channels = DIV_ROUND_UP(midi_ports, 8);
196 if (WARN_ON(amdtp_stream_running(s)) |
197 WARN_ON(pcm_channels > AMDTP_MAX_CHANNELS_FOR_PCM) |
198 WARN_ON(midi_channels > AMDTP_MAX_CHANNELS_FOR_MIDI))
201 for (sfc = 0; sfc < ARRAY_SIZE(amdtp_rate_table); ++sfc)
202 if (amdtp_rate_table[sfc] == rate)
208 s->pcm_channels = pcm_channels;
210 s->data_block_quadlets = s->pcm_channels + midi_channels;
211 s->midi_ports = midi_ports;
213 s->syt_interval = amdtp_syt_intervals[sfc];
215 /* default buffering in the device */
216 s->transfer_delay = TRANSFER_DELAY_TICKS - TICKS_PER_CYCLE;
217 if (s->flags & CIP_BLOCKING)
218 /* additional buffering needed to adjust for no-data packets */
219 s->transfer_delay += TICKS_PER_SECOND * s->syt_interval / rate;
221 /* init the position map for PCM and MIDI channels */
222 for (i = 0; i < pcm_channels; i++)
223 s->pcm_positions[i] = i;
224 s->midi_position = s->pcm_channels;
226 EXPORT_SYMBOL(amdtp_stream_set_parameters);
229 * amdtp_stream_get_max_payload - get the stream's packet size
230 * @s: the AMDTP stream
232 * This function must not be called before the stream has been configured
233 * with amdtp_stream_set_parameters().
235 unsigned int amdtp_stream_get_max_payload(struct amdtp_stream *s)
237 return 8 + s->syt_interval * s->data_block_quadlets * 4;
239 EXPORT_SYMBOL(amdtp_stream_get_max_payload);
241 static void amdtp_write_s16(struct amdtp_stream *s,
242 struct snd_pcm_substream *pcm,
243 __be32 *buffer, unsigned int frames);
244 static void amdtp_write_s32(struct amdtp_stream *s,
245 struct snd_pcm_substream *pcm,
246 __be32 *buffer, unsigned int frames);
247 static void amdtp_read_s32(struct amdtp_stream *s,
248 struct snd_pcm_substream *pcm,
249 __be32 *buffer, unsigned int frames);
252 * amdtp_stream_set_pcm_format - set the PCM format
253 * @s: the AMDTP stream to configure
254 * @format: the format of the ALSA PCM device
256 * The sample format must be set after the other paramters (rate/PCM channels/
257 * MIDI) and before the stream is started, and must not be changed while the
260 void amdtp_stream_set_pcm_format(struct amdtp_stream *s,
261 snd_pcm_format_t format)
263 if (WARN_ON(amdtp_stream_pcm_running(s)))
270 case SNDRV_PCM_FORMAT_S16:
271 if (s->direction == AMDTP_OUT_STREAM) {
272 s->transfer_samples = amdtp_write_s16;
277 case SNDRV_PCM_FORMAT_S32:
278 if (s->direction == AMDTP_OUT_STREAM)
279 s->transfer_samples = amdtp_write_s32;
281 s->transfer_samples = amdtp_read_s32;
285 EXPORT_SYMBOL(amdtp_stream_set_pcm_format);
288 * amdtp_stream_pcm_prepare - prepare PCM device for running
289 * @s: the AMDTP stream
291 * This function should be called from the PCM device's .prepare callback.
293 void amdtp_stream_pcm_prepare(struct amdtp_stream *s)
295 tasklet_kill(&s->period_tasklet);
296 s->pcm_buffer_pointer = 0;
297 s->pcm_period_pointer = 0;
298 s->pointer_flush = true;
300 EXPORT_SYMBOL(amdtp_stream_pcm_prepare);
302 static unsigned int calculate_data_blocks(struct amdtp_stream *s)
304 unsigned int phase, data_blocks;
306 if (s->flags & CIP_BLOCKING)
307 data_blocks = s->syt_interval;
308 else if (!cip_sfc_is_base_44100(s->sfc)) {
309 /* Sample_rate / 8000 is an integer, and precomputed. */
310 data_blocks = s->data_block_state;
312 phase = s->data_block_state;
315 * This calculates the number of data blocks per packet so that
316 * 1) the overall rate is correct and exactly synchronized to
318 * 2) packets with a rounded-up number of blocks occur as early
319 * as possible in the sequence (to prevent underruns of the
322 if (s->sfc == CIP_SFC_44100)
323 /* 6 6 5 6 5 6 5 ... */
324 data_blocks = 5 + ((phase & 1) ^
325 (phase == 0 || phase >= 40));
327 /* 12 11 11 11 11 ... or 23 22 22 22 22 ... */
328 data_blocks = 11 * (s->sfc >> 1) + (phase == 0);
329 if (++phase >= (80 >> (s->sfc >> 1)))
331 s->data_block_state = phase;
337 static unsigned int calculate_syt(struct amdtp_stream *s,
340 unsigned int syt_offset, phase, index, syt;
342 if (s->last_syt_offset < TICKS_PER_CYCLE) {
343 if (!cip_sfc_is_base_44100(s->sfc))
344 syt_offset = s->last_syt_offset + s->syt_offset_state;
347 * The time, in ticks, of the n'th SYT_INTERVAL sample is:
348 * n * SYT_INTERVAL * 24576000 / sample_rate
349 * Modulo TICKS_PER_CYCLE, the difference between successive
350 * elements is about 1386.23. Rounding the results of this
351 * formula to the SYT precision results in a sequence of
352 * differences that begins with:
353 * 1386 1386 1387 1386 1386 1386 1387 1386 1386 1386 1387 ...
354 * This code generates _exactly_ the same sequence.
356 phase = s->syt_offset_state;
358 syt_offset = s->last_syt_offset;
359 syt_offset += 1386 + ((index && !(index & 3)) ||
363 s->syt_offset_state = phase;
366 syt_offset = s->last_syt_offset - TICKS_PER_CYCLE;
367 s->last_syt_offset = syt_offset;
369 if (syt_offset < TICKS_PER_CYCLE) {
370 syt_offset += s->transfer_delay;
371 syt = (cycle + syt_offset / TICKS_PER_CYCLE) << 12;
372 syt += syt_offset % TICKS_PER_CYCLE;
374 return syt & CIP_SYT_MASK;
376 return CIP_SYT_NO_INFO;
380 static void amdtp_write_s32(struct amdtp_stream *s,
381 struct snd_pcm_substream *pcm,
382 __be32 *buffer, unsigned int frames)
384 struct snd_pcm_runtime *runtime = pcm->runtime;
385 unsigned int channels, remaining_frames, i, c;
388 channels = s->pcm_channels;
389 src = (void *)runtime->dma_area +
390 frames_to_bytes(runtime, s->pcm_buffer_pointer);
391 remaining_frames = runtime->buffer_size - s->pcm_buffer_pointer;
393 for (i = 0; i < frames; ++i) {
394 for (c = 0; c < channels; ++c) {
395 buffer[s->pcm_positions[c]] =
396 cpu_to_be32((*src >> 8) | 0x40000000);
399 buffer += s->data_block_quadlets;
400 if (--remaining_frames == 0)
401 src = (void *)runtime->dma_area;
405 static void amdtp_write_s16(struct amdtp_stream *s,
406 struct snd_pcm_substream *pcm,
407 __be32 *buffer, unsigned int frames)
409 struct snd_pcm_runtime *runtime = pcm->runtime;
410 unsigned int channels, remaining_frames, i, c;
413 channels = s->pcm_channels;
414 src = (void *)runtime->dma_area +
415 frames_to_bytes(runtime, s->pcm_buffer_pointer);
416 remaining_frames = runtime->buffer_size - s->pcm_buffer_pointer;
418 for (i = 0; i < frames; ++i) {
419 for (c = 0; c < channels; ++c) {
420 buffer[s->pcm_positions[c]] =
421 cpu_to_be32((*src << 8) | 0x42000000);
424 buffer += s->data_block_quadlets;
425 if (--remaining_frames == 0)
426 src = (void *)runtime->dma_area;
430 static void amdtp_read_s32(struct amdtp_stream *s,
431 struct snd_pcm_substream *pcm,
432 __be32 *buffer, unsigned int frames)
434 struct snd_pcm_runtime *runtime = pcm->runtime;
435 unsigned int channels, remaining_frames, i, c;
438 channels = s->pcm_channels;
439 dst = (void *)runtime->dma_area +
440 frames_to_bytes(runtime, s->pcm_buffer_pointer);
441 remaining_frames = runtime->buffer_size - s->pcm_buffer_pointer;
443 for (i = 0; i < frames; ++i) {
444 for (c = 0; c < channels; ++c) {
445 *dst = be32_to_cpu(buffer[s->pcm_positions[c]]) << 8;
448 buffer += s->data_block_quadlets;
449 if (--remaining_frames == 0)
450 dst = (void *)runtime->dma_area;
454 static void amdtp_fill_pcm_silence(struct amdtp_stream *s,
455 __be32 *buffer, unsigned int frames)
459 for (i = 0; i < frames; ++i) {
460 for (c = 0; c < s->pcm_channels; ++c)
461 buffer[s->pcm_positions[c]] = cpu_to_be32(0x40000000);
462 buffer += s->data_block_quadlets;
466 static void amdtp_fill_midi(struct amdtp_stream *s,
467 __be32 *buffer, unsigned int frames)
469 unsigned int f, port;
472 for (f = 0; f < frames; f++) {
473 buffer[s->midi_position] = 0;
474 b = (u8 *)&buffer[s->midi_position];
476 port = (s->data_block_counter + f) % 8;
477 if ((f >= s->rx_blocks_for_midi) ||
478 (s->midi[port] == NULL) ||
479 (snd_rawmidi_transmit(s->midi[port], b + 1, 1) <= 0))
484 buffer += s->data_block_quadlets;
488 static void amdtp_pull_midi(struct amdtp_stream *s,
489 __be32 *buffer, unsigned int frames)
491 unsigned int f, port;
495 for (f = 0; f < frames; f++) {
496 port = (s->data_block_counter + f) % 8;
497 b = (u8 *)&buffer[s->midi_position];
500 if ((1 <= len) && (len <= 3) && (s->midi[port]))
501 snd_rawmidi_receive(s->midi[port], b + 1, len);
503 buffer += s->data_block_quadlets;
507 static void update_pcm_pointers(struct amdtp_stream *s,
508 struct snd_pcm_substream *pcm,
512 ptr = s->pcm_buffer_pointer + frames;
513 if (ptr >= pcm->runtime->buffer_size)
514 ptr -= pcm->runtime->buffer_size;
515 ACCESS_ONCE(s->pcm_buffer_pointer) = ptr;
517 s->pcm_period_pointer += frames;
518 if (s->pcm_period_pointer >= pcm->runtime->period_size) {
519 s->pcm_period_pointer -= pcm->runtime->period_size;
520 s->pointer_flush = false;
521 tasklet_hi_schedule(&s->period_tasklet);
525 static void pcm_period_tasklet(unsigned long data)
527 struct amdtp_stream *s = (void *)data;
528 struct snd_pcm_substream *pcm = ACCESS_ONCE(s->pcm);
531 snd_pcm_period_elapsed(pcm);
534 static int queue_packet(struct amdtp_stream *s,
535 unsigned int header_length,
536 unsigned int payload_length, bool skip)
538 struct fw_iso_packet p = {0};
541 if (IS_ERR(s->context))
544 p.interrupt = IS_ALIGNED(s->packet_index + 1, INTERRUPT_INTERVAL);
546 p.header_length = header_length;
547 p.payload_length = (!skip) ? payload_length : 0;
549 err = fw_iso_context_queue(s->context, &p, &s->buffer.iso_buffer,
550 s->buffer.packets[s->packet_index].offset);
552 dev_err(&s->unit->device, "queueing error: %d\n", err);
556 if (++s->packet_index >= QUEUE_LENGTH)
562 static inline int queue_out_packet(struct amdtp_stream *s,
563 unsigned int payload_length, bool skip)
565 return queue_packet(s, OUT_PACKET_HEADER_SIZE,
566 payload_length, skip);
569 static inline int queue_in_packet(struct amdtp_stream *s)
571 return queue_packet(s, IN_PACKET_HEADER_SIZE,
572 amdtp_stream_get_max_payload(s), false);
575 static void handle_out_packet(struct amdtp_stream *s, unsigned int syt)
578 unsigned int data_blocks, payload_length;
579 struct snd_pcm_substream *pcm;
581 if (s->packet_index < 0)
584 /* this module generate empty packet for 'no data' */
585 if (!(s->flags & CIP_BLOCKING) || (syt != CIP_SYT_NO_INFO))
586 data_blocks = calculate_data_blocks(s);
590 buffer = s->buffer.packets[s->packet_index].buffer;
591 buffer[0] = cpu_to_be32(ACCESS_ONCE(s->source_node_id_field) |
592 (s->data_block_quadlets << AMDTP_DBS_SHIFT) |
593 s->data_block_counter);
594 buffer[1] = cpu_to_be32(CIP_EOH | CIP_FMT_AM | AMDTP_FDF_AM824 |
595 (s->sfc << CIP_FDF_SFC_SHIFT) | syt);
598 pcm = ACCESS_ONCE(s->pcm);
600 s->transfer_samples(s, pcm, buffer, data_blocks);
602 amdtp_fill_pcm_silence(s, buffer, data_blocks);
604 amdtp_fill_midi(s, buffer, data_blocks);
606 s->data_block_counter = (s->data_block_counter + data_blocks) & 0xff;
608 payload_length = 8 + data_blocks * 4 * s->data_block_quadlets;
609 if (queue_out_packet(s, payload_length, false) < 0) {
610 s->packet_index = -1;
611 amdtp_stream_pcm_abort(s);
616 update_pcm_pointers(s, pcm, data_blocks);
619 static void handle_in_packet(struct amdtp_stream *s,
620 unsigned int payload_quadlets,
624 unsigned int data_blocks, data_block_quadlets, data_block_counter,
626 struct snd_pcm_substream *pcm = NULL;
629 cip_header[0] = be32_to_cpu(buffer[0]);
630 cip_header[1] = be32_to_cpu(buffer[1]);
633 * This module supports 'Two-quadlet CIP header with SYT field'.
634 * For convenience, also check FMT field is AM824 or not.
636 if (((cip_header[0] & CIP_EOH_MASK) == CIP_EOH) ||
637 ((cip_header[1] & CIP_EOH_MASK) != CIP_EOH) ||
638 ((cip_header[1] & CIP_FMT_MASK) != CIP_FMT_AM)) {
639 dev_info_ratelimited(&s->unit->device,
640 "Invalid CIP header for AMDTP: %08X:%08X\n",
641 cip_header[0], cip_header[1]);
645 /* Calculate data blocks */
646 if (payload_quadlets < 3 ||
647 ((cip_header[1] & CIP_FDF_MASK) ==
648 (AMDTP_FDF_NO_DATA << CIP_FDF_SFC_SHIFT))) {
651 data_block_quadlets =
652 (cip_header[0] & AMDTP_DBS_MASK) >> AMDTP_DBS_SHIFT;
653 /* avoid division by zero */
654 if (data_block_quadlets == 0) {
655 dev_info_ratelimited(&s->unit->device,
656 "Detect invalid value in dbs field: %08X\n",
660 if (s->flags & CIP_WRONG_DBS)
661 data_block_quadlets = s->data_block_quadlets;
663 data_blocks = (payload_quadlets - 2) / data_block_quadlets;
666 /* Check data block counter continuity */
667 data_block_counter = cip_header[0] & AMDTP_DBC_MASK;
668 if (data_blocks == 0 && (s->flags & CIP_EMPTY_HAS_WRONG_DBC) &&
669 s->data_block_counter != UINT_MAX)
670 data_block_counter = s->data_block_counter;
672 if (((s->flags & CIP_SKIP_DBC_ZERO_CHECK) && data_block_counter == 0) ||
673 (s->data_block_counter == UINT_MAX)) {
675 } else if (!(s->flags & CIP_DBC_IS_END_EVENT)) {
676 lost = data_block_counter != s->data_block_counter;
678 if ((data_blocks > 0) && (s->tx_dbc_interval > 0))
679 dbc_interval = s->tx_dbc_interval;
681 dbc_interval = data_blocks;
683 lost = data_block_counter !=
684 ((s->data_block_counter + dbc_interval) & 0xff);
688 dev_info(&s->unit->device,
689 "Detect discontinuity of CIP: %02X %02X\n",
690 s->data_block_counter, data_block_counter);
694 if (data_blocks > 0) {
697 pcm = ACCESS_ONCE(s->pcm);
699 s->transfer_samples(s, pcm, buffer, data_blocks);
702 amdtp_pull_midi(s, buffer, data_blocks);
705 if (s->flags & CIP_DBC_IS_END_EVENT)
706 s->data_block_counter = data_block_counter;
708 s->data_block_counter =
709 (data_block_counter + data_blocks) & 0xff;
711 if (queue_in_packet(s) < 0)
715 update_pcm_pointers(s, pcm, data_blocks);
719 s->packet_index = -1;
720 amdtp_stream_pcm_abort(s);
723 static void out_stream_callback(struct fw_iso_context *context, u32 cycle,
724 size_t header_length, void *header,
727 struct amdtp_stream *s = private_data;
728 unsigned int i, syt, packets = header_length / 4;
731 * Compute the cycle of the last queued packet.
732 * (We need only the four lowest bits for the SYT, so we can ignore
733 * that bits 0-11 must wrap around at 3072.)
735 cycle += QUEUE_LENGTH - packets;
737 for (i = 0; i < packets; ++i) {
738 syt = calculate_syt(s, ++cycle);
739 handle_out_packet(s, syt);
741 fw_iso_context_queue_flush(s->context);
744 static void in_stream_callback(struct fw_iso_context *context, u32 cycle,
745 size_t header_length, void *header,
748 struct amdtp_stream *s = private_data;
749 unsigned int p, syt, packets, payload_quadlets;
750 __be32 *buffer, *headers = header;
752 /* The number of packets in buffer */
753 packets = header_length / IN_PACKET_HEADER_SIZE;
755 for (p = 0; p < packets; p++) {
756 if (s->packet_index < 0)
759 buffer = s->buffer.packets[s->packet_index].buffer;
761 /* Process sync slave stream */
762 if (s->sync_slave && s->sync_slave->callbacked) {
763 syt = be32_to_cpu(buffer[1]) & CIP_SYT_MASK;
764 handle_out_packet(s->sync_slave, syt);
767 /* The number of quadlets in this packet */
769 (be32_to_cpu(headers[p]) >> ISO_DATA_LENGTH_SHIFT) / 4;
770 handle_in_packet(s, payload_quadlets, buffer);
773 /* Queueing error or detecting discontinuity */
774 if (s->packet_index < 0) {
775 /* Abort sync slave. */
777 s->sync_slave->packet_index = -1;
778 amdtp_stream_pcm_abort(s->sync_slave);
783 /* when sync to device, flush the packets for slave stream */
784 if (s->sync_slave && s->sync_slave->callbacked)
785 fw_iso_context_queue_flush(s->sync_slave->context);
787 fw_iso_context_queue_flush(s->context);
790 /* processing is done by master callback */
791 static void slave_stream_callback(struct fw_iso_context *context, u32 cycle,
792 size_t header_length, void *header,
798 /* this is executed one time */
799 static void amdtp_stream_first_callback(struct fw_iso_context *context,
800 u32 cycle, size_t header_length,
801 void *header, void *private_data)
803 struct amdtp_stream *s = private_data;
806 * For in-stream, first packet has come.
807 * For out-stream, prepared to transmit first packet
809 s->callbacked = true;
810 wake_up(&s->callback_wait);
812 if (s->direction == AMDTP_IN_STREAM)
813 context->callback.sc = in_stream_callback;
814 else if ((s->flags & CIP_BLOCKING) && (s->flags & CIP_SYNC_TO_DEVICE))
815 context->callback.sc = slave_stream_callback;
817 context->callback.sc = out_stream_callback;
819 context->callback.sc(context, cycle, header_length, header, s);
823 * amdtp_stream_start - start transferring packets
824 * @s: the AMDTP stream to start
825 * @channel: the isochronous channel on the bus
826 * @speed: firewire speed code
828 * The stream cannot be started until it has been configured with
829 * amdtp_stream_set_parameters() and it must be started before any PCM or MIDI
830 * device can be started.
832 int amdtp_stream_start(struct amdtp_stream *s, int channel, int speed)
834 static const struct {
835 unsigned int data_block;
836 unsigned int syt_offset;
837 } initial_state[] = {
838 [CIP_SFC_32000] = { 4, 3072 },
839 [CIP_SFC_48000] = { 6, 1024 },
840 [CIP_SFC_96000] = { 12, 1024 },
841 [CIP_SFC_192000] = { 24, 1024 },
842 [CIP_SFC_44100] = { 0, 67 },
843 [CIP_SFC_88200] = { 0, 67 },
844 [CIP_SFC_176400] = { 0, 67 },
846 unsigned int header_size;
847 enum dma_data_direction dir;
850 mutex_lock(&s->mutex);
852 if (WARN_ON(amdtp_stream_running(s) ||
853 (s->data_block_quadlets < 1))) {
858 if (s->direction == AMDTP_IN_STREAM &&
859 s->flags & CIP_SKIP_INIT_DBC_CHECK)
860 s->data_block_counter = UINT_MAX;
862 s->data_block_counter = 0;
863 s->data_block_state = initial_state[s->sfc].data_block;
864 s->syt_offset_state = initial_state[s->sfc].syt_offset;
865 s->last_syt_offset = TICKS_PER_CYCLE;
867 /* initialize packet buffer */
868 if (s->direction == AMDTP_IN_STREAM) {
869 dir = DMA_FROM_DEVICE;
870 type = FW_ISO_CONTEXT_RECEIVE;
871 header_size = IN_PACKET_HEADER_SIZE;
874 type = FW_ISO_CONTEXT_TRANSMIT;
875 header_size = OUT_PACKET_HEADER_SIZE;
877 err = iso_packets_buffer_init(&s->buffer, s->unit, QUEUE_LENGTH,
878 amdtp_stream_get_max_payload(s), dir);
882 s->context = fw_iso_context_create(fw_parent_device(s->unit)->card,
883 type, channel, speed, header_size,
884 amdtp_stream_first_callback, s);
885 if (IS_ERR(s->context)) {
886 err = PTR_ERR(s->context);
888 dev_err(&s->unit->device,
889 "no free stream on this controller\n");
893 amdtp_stream_update(s);
897 if (s->direction == AMDTP_IN_STREAM)
898 err = queue_in_packet(s);
900 err = queue_out_packet(s, 0, true);
903 } while (s->packet_index > 0);
905 /* NOTE: TAG1 matches CIP. This just affects in stream. */
906 tag = FW_ISO_CONTEXT_MATCH_TAG1;
907 if (s->flags & CIP_EMPTY_WITH_TAG0)
908 tag |= FW_ISO_CONTEXT_MATCH_TAG0;
910 s->callbacked = false;
911 err = fw_iso_context_start(s->context, -1, 0, tag);
915 mutex_unlock(&s->mutex);
920 fw_iso_context_destroy(s->context);
921 s->context = ERR_PTR(-1);
923 iso_packets_buffer_destroy(&s->buffer, s->unit);
925 mutex_unlock(&s->mutex);
929 EXPORT_SYMBOL(amdtp_stream_start);
932 * amdtp_stream_pcm_pointer - get the PCM buffer position
933 * @s: the AMDTP stream that transports the PCM data
935 * Returns the current buffer position, in frames.
937 unsigned long amdtp_stream_pcm_pointer(struct amdtp_stream *s)
939 /* this optimization is allowed to be racy */
940 if (s->pointer_flush && amdtp_stream_running(s))
941 fw_iso_context_flush_completions(s->context);
943 s->pointer_flush = true;
945 return ACCESS_ONCE(s->pcm_buffer_pointer);
947 EXPORT_SYMBOL(amdtp_stream_pcm_pointer);
950 * amdtp_stream_update - update the stream after a bus reset
951 * @s: the AMDTP stream
953 void amdtp_stream_update(struct amdtp_stream *s)
955 ACCESS_ONCE(s->source_node_id_field) =
956 (fw_parent_device(s->unit)->card->node_id & 0x3f) << 24;
958 EXPORT_SYMBOL(amdtp_stream_update);
961 * amdtp_stream_stop - stop sending packets
962 * @s: the AMDTP stream to stop
964 * All PCM and MIDI devices of the stream must be stopped before the stream
965 * itself can be stopped.
967 void amdtp_stream_stop(struct amdtp_stream *s)
969 mutex_lock(&s->mutex);
971 if (!amdtp_stream_running(s)) {
972 mutex_unlock(&s->mutex);
976 tasklet_kill(&s->period_tasklet);
977 fw_iso_context_stop(s->context);
978 fw_iso_context_destroy(s->context);
979 s->context = ERR_PTR(-1);
980 iso_packets_buffer_destroy(&s->buffer, s->unit);
982 s->callbacked = false;
984 mutex_unlock(&s->mutex);
986 EXPORT_SYMBOL(amdtp_stream_stop);
989 * amdtp_stream_pcm_abort - abort the running PCM device
990 * @s: the AMDTP stream about to be stopped
992 * If the isochronous stream needs to be stopped asynchronously, call this
993 * function first to stop the PCM device.
995 void amdtp_stream_pcm_abort(struct amdtp_stream *s)
997 struct snd_pcm_substream *pcm;
999 pcm = ACCESS_ONCE(s->pcm);
1001 snd_pcm_stream_lock_irq(pcm);
1002 if (snd_pcm_running(pcm))
1003 snd_pcm_stop(pcm, SNDRV_PCM_STATE_XRUN);
1004 snd_pcm_stream_unlock_irq(pcm);
1007 EXPORT_SYMBOL(amdtp_stream_pcm_abort);