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)
25 * Several devices look only at the first eight data blocks.
26 * In any case, this is more than enough for the MIDI data rate.
28 #define MAX_MIDI_RX_BLOCKS 8
30 #define TRANSFER_DELAY_TICKS 0x2e00 /* 479.17 µs */
32 /* isochronous header parameters */
33 #define ISO_DATA_LENGTH_SHIFT 16
36 /* common isochronous packet header parameters */
37 #define CIP_EOH (1u << 31)
38 #define CIP_EOH_MASK 0x80000000
39 #define CIP_FMT_AM (0x10 << 24)
40 #define CIP_FMT_MASK 0x3f000000
41 #define CIP_SYT_MASK 0x0000ffff
42 #define CIP_SYT_NO_INFO 0xffff
43 #define CIP_FDF_MASK 0x00ff0000
44 #define CIP_FDF_SFC_SHIFT 16
47 * Audio and Music transfer protocol specific parameters
48 * only "Clock-based rate control mode" is supported
50 #define AMDTP_FDF_AM824 (0 << (CIP_FDF_SFC_SHIFT + 3))
51 #define AMDTP_FDF_NO_DATA 0xff
52 #define AMDTP_DBS_MASK 0x00ff0000
53 #define AMDTP_DBS_SHIFT 16
54 #define AMDTP_DBC_MASK 0x000000ff
56 /* TODO: make these configurable */
57 #define INTERRUPT_INTERVAL 16
58 #define QUEUE_LENGTH 48
60 #define IN_PACKET_HEADER_SIZE 4
61 #define OUT_PACKET_HEADER_SIZE 0
63 static void pcm_period_tasklet(unsigned long data);
66 * amdtp_stream_init - initialize an AMDTP stream structure
67 * @s: the AMDTP stream to initialize
68 * @unit: the target of the stream
69 * @dir: the direction of stream
70 * @flags: the packet transmission method to use
72 int amdtp_stream_init(struct amdtp_stream *s, struct fw_unit *unit,
73 enum amdtp_stream_direction dir, enum cip_flags flags)
75 s->unit = fw_unit_get(unit);
78 s->context = ERR_PTR(-1);
79 mutex_init(&s->mutex);
80 tasklet_init(&s->period_tasklet, pcm_period_tasklet, (unsigned long)s);
83 init_waitqueue_head(&s->callback_wait);
84 s->callbacked = false;
89 EXPORT_SYMBOL(amdtp_stream_init);
92 * amdtp_stream_destroy - free stream resources
93 * @s: the AMDTP stream to destroy
95 void amdtp_stream_destroy(struct amdtp_stream *s)
97 WARN_ON(amdtp_stream_running(s));
98 mutex_destroy(&s->mutex);
101 EXPORT_SYMBOL(amdtp_stream_destroy);
103 const unsigned int amdtp_syt_intervals[CIP_SFC_COUNT] = {
107 [CIP_SFC_88200] = 16,
108 [CIP_SFC_96000] = 16,
109 [CIP_SFC_176400] = 32,
110 [CIP_SFC_192000] = 32,
112 EXPORT_SYMBOL(amdtp_syt_intervals);
114 const unsigned int amdtp_rate_table[CIP_SFC_COUNT] = {
115 [CIP_SFC_32000] = 32000,
116 [CIP_SFC_44100] = 44100,
117 [CIP_SFC_48000] = 48000,
118 [CIP_SFC_88200] = 88200,
119 [CIP_SFC_96000] = 96000,
120 [CIP_SFC_176400] = 176400,
121 [CIP_SFC_192000] = 192000,
123 EXPORT_SYMBOL(amdtp_rate_table);
126 * amdtp_stream_add_pcm_hw_constraints - add hw constraints for PCM substream
127 * @s: the AMDTP stream, which must be initialized.
128 * @runtime: the PCM substream runtime
130 int amdtp_stream_add_pcm_hw_constraints(struct amdtp_stream *s,
131 struct snd_pcm_runtime *runtime)
135 /* AM824 in IEC 61883-6 can deliver 24bit data */
136 err = snd_pcm_hw_constraint_msbits(runtime, 0, 32, 24);
141 * Currently firewire-lib processes 16 packets in one software
142 * interrupt callback. This equals to 2msec but actually the
143 * interval of the interrupts has a jitter.
144 * Additionally, even if adding a constraint to fit period size to
145 * 2msec, actual calculated frames per period doesn't equal to 2msec,
146 * depending on sampling rate.
147 * Anyway, the interval to call snd_pcm_period_elapsed() cannot 2msec.
148 * Here let us use 5msec for safe period interrupt.
150 err = snd_pcm_hw_constraint_minmax(runtime,
151 SNDRV_PCM_HW_PARAM_PERIOD_TIME,
156 /* Non-Blocking stream has no more constraints */
157 if (!(s->flags & CIP_BLOCKING))
161 * One AMDTP packet can include some frames. In blocking mode, the
162 * number equals to SYT_INTERVAL. So the number is 8, 16 or 32,
163 * depending on its sampling rate. For accurate period interrupt, it's
164 * preferrable to aligh period/buffer sizes to current SYT_INTERVAL.
166 * TODO: These constraints can be improved with propper rules.
167 * Currently apply LCM of SYT_INTEVALs.
169 err = snd_pcm_hw_constraint_step(runtime, 0,
170 SNDRV_PCM_HW_PARAM_PERIOD_SIZE, 32);
173 err = snd_pcm_hw_constraint_step(runtime, 0,
174 SNDRV_PCM_HW_PARAM_BUFFER_SIZE, 32);
178 EXPORT_SYMBOL(amdtp_stream_add_pcm_hw_constraints);
181 * amdtp_stream_set_parameters - set stream parameters
182 * @s: the AMDTP stream to configure
183 * @rate: the sample rate
184 * @pcm_channels: the number of PCM samples in each data block, to be encoded
185 * as AM824 multi-bit linear audio
186 * @midi_ports: the number of MIDI ports (i.e., MPX-MIDI Data Channels)
188 * The parameters must be set before the stream is started, and must not be
189 * changed while the stream is running.
191 void amdtp_stream_set_parameters(struct amdtp_stream *s,
193 unsigned int pcm_channels,
194 unsigned int midi_ports)
196 unsigned int i, sfc, midi_channels;
198 midi_channels = DIV_ROUND_UP(midi_ports, 8);
200 if (WARN_ON(amdtp_stream_running(s)) |
201 WARN_ON(pcm_channels > AMDTP_MAX_CHANNELS_FOR_PCM) |
202 WARN_ON(midi_channels > AMDTP_MAX_CHANNELS_FOR_MIDI))
205 for (sfc = 0; sfc < ARRAY_SIZE(amdtp_rate_table); ++sfc)
206 if (amdtp_rate_table[sfc] == rate)
212 s->pcm_channels = pcm_channels;
214 s->data_block_quadlets = s->pcm_channels + midi_channels;
215 s->midi_ports = midi_ports;
217 s->syt_interval = amdtp_syt_intervals[sfc];
219 /* default buffering in the device */
220 s->transfer_delay = TRANSFER_DELAY_TICKS - TICKS_PER_CYCLE;
221 if (s->flags & CIP_BLOCKING)
222 /* additional buffering needed to adjust for no-data packets */
223 s->transfer_delay += TICKS_PER_SECOND * s->syt_interval / rate;
225 /* init the position map for PCM and MIDI channels */
226 for (i = 0; i < pcm_channels; i++)
227 s->pcm_positions[i] = i;
228 s->midi_position = s->pcm_channels;
230 EXPORT_SYMBOL(amdtp_stream_set_parameters);
233 * amdtp_stream_get_max_payload - get the stream's packet size
234 * @s: the AMDTP stream
236 * This function must not be called before the stream has been configured
237 * with amdtp_stream_set_parameters().
239 unsigned int amdtp_stream_get_max_payload(struct amdtp_stream *s)
241 return 8 + s->syt_interval * s->data_block_quadlets * 4;
243 EXPORT_SYMBOL(amdtp_stream_get_max_payload);
245 static void amdtp_write_s16(struct amdtp_stream *s,
246 struct snd_pcm_substream *pcm,
247 __be32 *buffer, unsigned int frames);
248 static void amdtp_write_s32(struct amdtp_stream *s,
249 struct snd_pcm_substream *pcm,
250 __be32 *buffer, unsigned int frames);
251 static void amdtp_read_s32(struct amdtp_stream *s,
252 struct snd_pcm_substream *pcm,
253 __be32 *buffer, unsigned int frames);
256 * amdtp_stream_set_pcm_format - set the PCM format
257 * @s: the AMDTP stream to configure
258 * @format: the format of the ALSA PCM device
260 * The sample format must be set after the other paramters (rate/PCM channels/
261 * MIDI) and before the stream is started, and must not be changed while the
264 void amdtp_stream_set_pcm_format(struct amdtp_stream *s,
265 snd_pcm_format_t format)
267 if (WARN_ON(amdtp_stream_pcm_running(s)))
274 case SNDRV_PCM_FORMAT_S16:
275 if (s->direction == AMDTP_OUT_STREAM) {
276 s->transfer_samples = amdtp_write_s16;
281 case SNDRV_PCM_FORMAT_S32:
282 if (s->direction == AMDTP_OUT_STREAM)
283 s->transfer_samples = amdtp_write_s32;
285 s->transfer_samples = amdtp_read_s32;
289 EXPORT_SYMBOL(amdtp_stream_set_pcm_format);
292 * amdtp_stream_pcm_prepare - prepare PCM device for running
293 * @s: the AMDTP stream
295 * This function should be called from the PCM device's .prepare callback.
297 void amdtp_stream_pcm_prepare(struct amdtp_stream *s)
299 tasklet_kill(&s->period_tasklet);
300 s->pcm_buffer_pointer = 0;
301 s->pcm_period_pointer = 0;
302 s->pointer_flush = true;
304 EXPORT_SYMBOL(amdtp_stream_pcm_prepare);
306 static unsigned int calculate_data_blocks(struct amdtp_stream *s)
308 unsigned int phase, data_blocks;
310 if (s->flags & CIP_BLOCKING)
311 data_blocks = s->syt_interval;
312 else if (!cip_sfc_is_base_44100(s->sfc)) {
313 /* Sample_rate / 8000 is an integer, and precomputed. */
314 data_blocks = s->data_block_state;
316 phase = s->data_block_state;
319 * This calculates the number of data blocks per packet so that
320 * 1) the overall rate is correct and exactly synchronized to
322 * 2) packets with a rounded-up number of blocks occur as early
323 * as possible in the sequence (to prevent underruns of the
326 if (s->sfc == CIP_SFC_44100)
327 /* 6 6 5 6 5 6 5 ... */
328 data_blocks = 5 + ((phase & 1) ^
329 (phase == 0 || phase >= 40));
331 /* 12 11 11 11 11 ... or 23 22 22 22 22 ... */
332 data_blocks = 11 * (s->sfc >> 1) + (phase == 0);
333 if (++phase >= (80 >> (s->sfc >> 1)))
335 s->data_block_state = phase;
341 static unsigned int calculate_syt(struct amdtp_stream *s,
344 unsigned int syt_offset, phase, index, syt;
346 if (s->last_syt_offset < TICKS_PER_CYCLE) {
347 if (!cip_sfc_is_base_44100(s->sfc))
348 syt_offset = s->last_syt_offset + s->syt_offset_state;
351 * The time, in ticks, of the n'th SYT_INTERVAL sample is:
352 * n * SYT_INTERVAL * 24576000 / sample_rate
353 * Modulo TICKS_PER_CYCLE, the difference between successive
354 * elements is about 1386.23. Rounding the results of this
355 * formula to the SYT precision results in a sequence of
356 * differences that begins with:
357 * 1386 1386 1387 1386 1386 1386 1387 1386 1386 1386 1387 ...
358 * This code generates _exactly_ the same sequence.
360 phase = s->syt_offset_state;
362 syt_offset = s->last_syt_offset;
363 syt_offset += 1386 + ((index && !(index & 3)) ||
367 s->syt_offset_state = phase;
370 syt_offset = s->last_syt_offset - TICKS_PER_CYCLE;
371 s->last_syt_offset = syt_offset;
373 if (syt_offset < TICKS_PER_CYCLE) {
374 syt_offset += s->transfer_delay;
375 syt = (cycle + syt_offset / TICKS_PER_CYCLE) << 12;
376 syt += syt_offset % TICKS_PER_CYCLE;
378 return syt & CIP_SYT_MASK;
380 return CIP_SYT_NO_INFO;
384 static void amdtp_write_s32(struct amdtp_stream *s,
385 struct snd_pcm_substream *pcm,
386 __be32 *buffer, unsigned int frames)
388 struct snd_pcm_runtime *runtime = pcm->runtime;
389 unsigned int channels, remaining_frames, i, c;
392 channels = s->pcm_channels;
393 src = (void *)runtime->dma_area +
394 frames_to_bytes(runtime, s->pcm_buffer_pointer);
395 remaining_frames = runtime->buffer_size - s->pcm_buffer_pointer;
397 for (i = 0; i < frames; ++i) {
398 for (c = 0; c < channels; ++c) {
399 buffer[s->pcm_positions[c]] =
400 cpu_to_be32((*src >> 8) | 0x40000000);
403 buffer += s->data_block_quadlets;
404 if (--remaining_frames == 0)
405 src = (void *)runtime->dma_area;
409 static void amdtp_write_s16(struct amdtp_stream *s,
410 struct snd_pcm_substream *pcm,
411 __be32 *buffer, unsigned int frames)
413 struct snd_pcm_runtime *runtime = pcm->runtime;
414 unsigned int channels, remaining_frames, i, c;
417 channels = s->pcm_channels;
418 src = (void *)runtime->dma_area +
419 frames_to_bytes(runtime, s->pcm_buffer_pointer);
420 remaining_frames = runtime->buffer_size - s->pcm_buffer_pointer;
422 for (i = 0; i < frames; ++i) {
423 for (c = 0; c < channels; ++c) {
424 buffer[s->pcm_positions[c]] =
425 cpu_to_be32((*src << 8) | 0x42000000);
428 buffer += s->data_block_quadlets;
429 if (--remaining_frames == 0)
430 src = (void *)runtime->dma_area;
434 static void amdtp_read_s32(struct amdtp_stream *s,
435 struct snd_pcm_substream *pcm,
436 __be32 *buffer, unsigned int frames)
438 struct snd_pcm_runtime *runtime = pcm->runtime;
439 unsigned int channels, remaining_frames, i, c;
442 channels = s->pcm_channels;
443 dst = (void *)runtime->dma_area +
444 frames_to_bytes(runtime, s->pcm_buffer_pointer);
445 remaining_frames = runtime->buffer_size - s->pcm_buffer_pointer;
447 for (i = 0; i < frames; ++i) {
448 for (c = 0; c < channels; ++c) {
449 *dst = be32_to_cpu(buffer[s->pcm_positions[c]]) << 8;
452 buffer += s->data_block_quadlets;
453 if (--remaining_frames == 0)
454 dst = (void *)runtime->dma_area;
458 static void amdtp_fill_pcm_silence(struct amdtp_stream *s,
459 __be32 *buffer, unsigned int frames)
463 for (i = 0; i < frames; ++i) {
464 for (c = 0; c < s->pcm_channels; ++c)
465 buffer[s->pcm_positions[c]] = cpu_to_be32(0x40000000);
466 buffer += s->data_block_quadlets;
470 static void amdtp_fill_midi(struct amdtp_stream *s,
471 __be32 *buffer, unsigned int frames)
473 unsigned int f, port;
476 for (f = 0; f < frames; f++) {
477 buffer[s->midi_position] = 0;
478 b = (u8 *)&buffer[s->midi_position];
480 port = (s->data_block_counter + f) % 8;
481 if ((f >= MAX_MIDI_RX_BLOCKS) ||
482 (s->midi[port] == NULL) ||
483 (snd_rawmidi_transmit(s->midi[port], b + 1, 1) <= 0))
488 buffer += s->data_block_quadlets;
492 static void amdtp_pull_midi(struct amdtp_stream *s,
493 __be32 *buffer, unsigned int frames)
495 unsigned int f, port;
499 for (f = 0; f < frames; f++) {
500 port = (s->data_block_counter + f) % 8;
501 b = (u8 *)&buffer[s->midi_position];
504 if ((1 <= len) && (len <= 3) && (s->midi[port]))
505 snd_rawmidi_receive(s->midi[port], b + 1, len);
507 buffer += s->data_block_quadlets;
511 static void update_pcm_pointers(struct amdtp_stream *s,
512 struct snd_pcm_substream *pcm,
518 * In IEC 61883-6, one data block represents one event. In ALSA, one
519 * event equals to one PCM frame. But Dice has a quirk to transfer
520 * two PCM frames in one data block.
522 if (s->double_pcm_frames)
525 ptr = s->pcm_buffer_pointer + frames;
526 if (ptr >= pcm->runtime->buffer_size)
527 ptr -= pcm->runtime->buffer_size;
528 ACCESS_ONCE(s->pcm_buffer_pointer) = ptr;
530 s->pcm_period_pointer += frames;
531 if (s->pcm_period_pointer >= pcm->runtime->period_size) {
532 s->pcm_period_pointer -= pcm->runtime->period_size;
533 s->pointer_flush = false;
534 tasklet_hi_schedule(&s->period_tasklet);
538 static void pcm_period_tasklet(unsigned long data)
540 struct amdtp_stream *s = (void *)data;
541 struct snd_pcm_substream *pcm = ACCESS_ONCE(s->pcm);
544 snd_pcm_period_elapsed(pcm);
547 static int queue_packet(struct amdtp_stream *s,
548 unsigned int header_length,
549 unsigned int payload_length, bool skip)
551 struct fw_iso_packet p = {0};
554 if (IS_ERR(s->context))
557 p.interrupt = IS_ALIGNED(s->packet_index + 1, INTERRUPT_INTERVAL);
559 p.header_length = header_length;
560 p.payload_length = (!skip) ? payload_length : 0;
562 err = fw_iso_context_queue(s->context, &p, &s->buffer.iso_buffer,
563 s->buffer.packets[s->packet_index].offset);
565 dev_err(&s->unit->device, "queueing error: %d\n", err);
569 if (++s->packet_index >= QUEUE_LENGTH)
575 static inline int queue_out_packet(struct amdtp_stream *s,
576 unsigned int payload_length, bool skip)
578 return queue_packet(s, OUT_PACKET_HEADER_SIZE,
579 payload_length, skip);
582 static inline int queue_in_packet(struct amdtp_stream *s)
584 return queue_packet(s, IN_PACKET_HEADER_SIZE,
585 amdtp_stream_get_max_payload(s), false);
588 static void handle_out_packet(struct amdtp_stream *s, unsigned int syt)
591 unsigned int data_blocks, payload_length;
592 struct snd_pcm_substream *pcm;
594 if (s->packet_index < 0)
597 /* this module generate empty packet for 'no data' */
598 if (!(s->flags & CIP_BLOCKING) || (syt != CIP_SYT_NO_INFO))
599 data_blocks = calculate_data_blocks(s);
603 buffer = s->buffer.packets[s->packet_index].buffer;
604 buffer[0] = cpu_to_be32(ACCESS_ONCE(s->source_node_id_field) |
605 (s->data_block_quadlets << AMDTP_DBS_SHIFT) |
606 s->data_block_counter);
607 buffer[1] = cpu_to_be32(CIP_EOH | CIP_FMT_AM | AMDTP_FDF_AM824 |
608 (s->sfc << CIP_FDF_SFC_SHIFT) | syt);
611 pcm = ACCESS_ONCE(s->pcm);
613 s->transfer_samples(s, pcm, buffer, data_blocks);
615 amdtp_fill_pcm_silence(s, buffer, data_blocks);
617 amdtp_fill_midi(s, buffer, data_blocks);
619 s->data_block_counter = (s->data_block_counter + data_blocks) & 0xff;
621 payload_length = 8 + data_blocks * 4 * s->data_block_quadlets;
622 if (queue_out_packet(s, payload_length, false) < 0) {
623 s->packet_index = -1;
624 amdtp_stream_pcm_abort(s);
629 update_pcm_pointers(s, pcm, data_blocks);
632 static void handle_in_packet(struct amdtp_stream *s,
633 unsigned int payload_quadlets,
637 unsigned int data_blocks, data_block_quadlets, data_block_counter,
639 struct snd_pcm_substream *pcm = NULL;
642 cip_header[0] = be32_to_cpu(buffer[0]);
643 cip_header[1] = be32_to_cpu(buffer[1]);
646 * This module supports 'Two-quadlet CIP header with SYT field'.
647 * For convenience, also check FMT field is AM824 or not.
649 if (((cip_header[0] & CIP_EOH_MASK) == CIP_EOH) ||
650 ((cip_header[1] & CIP_EOH_MASK) != CIP_EOH) ||
651 ((cip_header[1] & CIP_FMT_MASK) != CIP_FMT_AM)) {
652 dev_info_ratelimited(&s->unit->device,
653 "Invalid CIP header for AMDTP: %08X:%08X\n",
654 cip_header[0], cip_header[1]);
658 /* Calculate data blocks */
659 if (payload_quadlets < 3 ||
660 ((cip_header[1] & CIP_FDF_MASK) ==
661 (AMDTP_FDF_NO_DATA << CIP_FDF_SFC_SHIFT))) {
664 data_block_quadlets =
665 (cip_header[0] & AMDTP_DBS_MASK) >> AMDTP_DBS_SHIFT;
666 /* avoid division by zero */
667 if (data_block_quadlets == 0) {
668 dev_info_ratelimited(&s->unit->device,
669 "Detect invalid value in dbs field: %08X\n",
673 if (s->flags & CIP_WRONG_DBS)
674 data_block_quadlets = s->data_block_quadlets;
676 data_blocks = (payload_quadlets - 2) / data_block_quadlets;
679 /* Check data block counter continuity */
680 data_block_counter = cip_header[0] & AMDTP_DBC_MASK;
681 if (data_blocks == 0 && (s->flags & CIP_EMPTY_HAS_WRONG_DBC) &&
682 s->data_block_counter != UINT_MAX)
683 data_block_counter = s->data_block_counter;
685 if (((s->flags & CIP_SKIP_DBC_ZERO_CHECK) && data_block_counter == 0) ||
686 (s->data_block_counter == UINT_MAX)) {
688 } else if (!(s->flags & CIP_DBC_IS_END_EVENT)) {
689 lost = data_block_counter != s->data_block_counter;
691 if ((data_blocks > 0) && (s->tx_dbc_interval > 0))
692 dbc_interval = s->tx_dbc_interval;
694 dbc_interval = data_blocks;
696 lost = data_block_counter !=
697 ((s->data_block_counter + dbc_interval) & 0xff);
701 dev_info(&s->unit->device,
702 "Detect discontinuity of CIP: %02X %02X\n",
703 s->data_block_counter, data_block_counter);
707 if (data_blocks > 0) {
710 pcm = ACCESS_ONCE(s->pcm);
712 s->transfer_samples(s, pcm, buffer, data_blocks);
715 amdtp_pull_midi(s, buffer, data_blocks);
718 if (s->flags & CIP_DBC_IS_END_EVENT)
719 s->data_block_counter = data_block_counter;
721 s->data_block_counter =
722 (data_block_counter + data_blocks) & 0xff;
724 if (queue_in_packet(s) < 0)
728 update_pcm_pointers(s, pcm, data_blocks);
732 s->packet_index = -1;
733 amdtp_stream_pcm_abort(s);
736 static void out_stream_callback(struct fw_iso_context *context, u32 cycle,
737 size_t header_length, void *header,
740 struct amdtp_stream *s = private_data;
741 unsigned int i, syt, packets = header_length / 4;
744 * Compute the cycle of the last queued packet.
745 * (We need only the four lowest bits for the SYT, so we can ignore
746 * that bits 0-11 must wrap around at 3072.)
748 cycle += QUEUE_LENGTH - packets;
750 for (i = 0; i < packets; ++i) {
751 syt = calculate_syt(s, ++cycle);
752 handle_out_packet(s, syt);
754 fw_iso_context_queue_flush(s->context);
757 static void in_stream_callback(struct fw_iso_context *context, u32 cycle,
758 size_t header_length, void *header,
761 struct amdtp_stream *s = private_data;
762 unsigned int p, syt, packets, payload_quadlets;
763 __be32 *buffer, *headers = header;
765 /* The number of packets in buffer */
766 packets = header_length / IN_PACKET_HEADER_SIZE;
768 for (p = 0; p < packets; p++) {
769 if (s->packet_index < 0)
772 buffer = s->buffer.packets[s->packet_index].buffer;
774 /* Process sync slave stream */
775 if (s->sync_slave && s->sync_slave->callbacked) {
776 syt = be32_to_cpu(buffer[1]) & CIP_SYT_MASK;
777 handle_out_packet(s->sync_slave, syt);
780 /* The number of quadlets in this packet */
782 (be32_to_cpu(headers[p]) >> ISO_DATA_LENGTH_SHIFT) / 4;
783 handle_in_packet(s, payload_quadlets, buffer);
786 /* Queueing error or detecting discontinuity */
787 if (s->packet_index < 0) {
788 /* Abort sync slave. */
790 s->sync_slave->packet_index = -1;
791 amdtp_stream_pcm_abort(s->sync_slave);
796 /* when sync to device, flush the packets for slave stream */
797 if (s->sync_slave && s->sync_slave->callbacked)
798 fw_iso_context_queue_flush(s->sync_slave->context);
800 fw_iso_context_queue_flush(s->context);
803 /* processing is done by master callback */
804 static void slave_stream_callback(struct fw_iso_context *context, u32 cycle,
805 size_t header_length, void *header,
811 /* this is executed one time */
812 static void amdtp_stream_first_callback(struct fw_iso_context *context,
813 u32 cycle, size_t header_length,
814 void *header, void *private_data)
816 struct amdtp_stream *s = private_data;
819 * For in-stream, first packet has come.
820 * For out-stream, prepared to transmit first packet
822 s->callbacked = true;
823 wake_up(&s->callback_wait);
825 if (s->direction == AMDTP_IN_STREAM)
826 context->callback.sc = in_stream_callback;
827 else if ((s->flags & CIP_BLOCKING) && (s->flags & CIP_SYNC_TO_DEVICE))
828 context->callback.sc = slave_stream_callback;
830 context->callback.sc = out_stream_callback;
832 context->callback.sc(context, cycle, header_length, header, s);
836 * amdtp_stream_start - start transferring packets
837 * @s: the AMDTP stream to start
838 * @channel: the isochronous channel on the bus
839 * @speed: firewire speed code
841 * The stream cannot be started until it has been configured with
842 * amdtp_stream_set_parameters() and it must be started before any PCM or MIDI
843 * device can be started.
845 int amdtp_stream_start(struct amdtp_stream *s, int channel, int speed)
847 static const struct {
848 unsigned int data_block;
849 unsigned int syt_offset;
850 } initial_state[] = {
851 [CIP_SFC_32000] = { 4, 3072 },
852 [CIP_SFC_48000] = { 6, 1024 },
853 [CIP_SFC_96000] = { 12, 1024 },
854 [CIP_SFC_192000] = { 24, 1024 },
855 [CIP_SFC_44100] = { 0, 67 },
856 [CIP_SFC_88200] = { 0, 67 },
857 [CIP_SFC_176400] = { 0, 67 },
859 unsigned int header_size;
860 enum dma_data_direction dir;
863 mutex_lock(&s->mutex);
865 if (WARN_ON(amdtp_stream_running(s) ||
866 (s->data_block_quadlets < 1))) {
871 if (s->direction == AMDTP_IN_STREAM &&
872 s->flags & CIP_SKIP_INIT_DBC_CHECK)
873 s->data_block_counter = UINT_MAX;
875 s->data_block_counter = 0;
876 s->data_block_state = initial_state[s->sfc].data_block;
877 s->syt_offset_state = initial_state[s->sfc].syt_offset;
878 s->last_syt_offset = TICKS_PER_CYCLE;
880 /* initialize packet buffer */
881 if (s->direction == AMDTP_IN_STREAM) {
882 dir = DMA_FROM_DEVICE;
883 type = FW_ISO_CONTEXT_RECEIVE;
884 header_size = IN_PACKET_HEADER_SIZE;
887 type = FW_ISO_CONTEXT_TRANSMIT;
888 header_size = OUT_PACKET_HEADER_SIZE;
890 err = iso_packets_buffer_init(&s->buffer, s->unit, QUEUE_LENGTH,
891 amdtp_stream_get_max_payload(s), dir);
895 s->context = fw_iso_context_create(fw_parent_device(s->unit)->card,
896 type, channel, speed, header_size,
897 amdtp_stream_first_callback, s);
898 if (IS_ERR(s->context)) {
899 err = PTR_ERR(s->context);
901 dev_err(&s->unit->device,
902 "no free stream on this controller\n");
906 amdtp_stream_update(s);
910 if (s->direction == AMDTP_IN_STREAM)
911 err = queue_in_packet(s);
913 err = queue_out_packet(s, 0, true);
916 } while (s->packet_index > 0);
918 /* NOTE: TAG1 matches CIP. This just affects in stream. */
919 tag = FW_ISO_CONTEXT_MATCH_TAG1;
920 if (s->flags & CIP_EMPTY_WITH_TAG0)
921 tag |= FW_ISO_CONTEXT_MATCH_TAG0;
923 s->callbacked = false;
924 err = fw_iso_context_start(s->context, -1, 0, tag);
928 mutex_unlock(&s->mutex);
933 fw_iso_context_destroy(s->context);
934 s->context = ERR_PTR(-1);
936 iso_packets_buffer_destroy(&s->buffer, s->unit);
938 mutex_unlock(&s->mutex);
942 EXPORT_SYMBOL(amdtp_stream_start);
945 * amdtp_stream_pcm_pointer - get the PCM buffer position
946 * @s: the AMDTP stream that transports the PCM data
948 * Returns the current buffer position, in frames.
950 unsigned long amdtp_stream_pcm_pointer(struct amdtp_stream *s)
952 /* this optimization is allowed to be racy */
953 if (s->pointer_flush && amdtp_stream_running(s))
954 fw_iso_context_flush_completions(s->context);
956 s->pointer_flush = true;
958 return ACCESS_ONCE(s->pcm_buffer_pointer);
960 EXPORT_SYMBOL(amdtp_stream_pcm_pointer);
963 * amdtp_stream_update - update the stream after a bus reset
964 * @s: the AMDTP stream
966 void amdtp_stream_update(struct amdtp_stream *s)
968 ACCESS_ONCE(s->source_node_id_field) =
969 (fw_parent_device(s->unit)->card->node_id & 0x3f) << 24;
971 EXPORT_SYMBOL(amdtp_stream_update);
974 * amdtp_stream_stop - stop sending packets
975 * @s: the AMDTP stream to stop
977 * All PCM and MIDI devices of the stream must be stopped before the stream
978 * itself can be stopped.
980 void amdtp_stream_stop(struct amdtp_stream *s)
982 mutex_lock(&s->mutex);
984 if (!amdtp_stream_running(s)) {
985 mutex_unlock(&s->mutex);
989 tasklet_kill(&s->period_tasklet);
990 fw_iso_context_stop(s->context);
991 fw_iso_context_destroy(s->context);
992 s->context = ERR_PTR(-1);
993 iso_packets_buffer_destroy(&s->buffer, s->unit);
995 s->callbacked = false;
997 mutex_unlock(&s->mutex);
999 EXPORT_SYMBOL(amdtp_stream_stop);
1002 * amdtp_stream_pcm_abort - abort the running PCM device
1003 * @s: the AMDTP stream about to be stopped
1005 * If the isochronous stream needs to be stopped asynchronously, call this
1006 * function first to stop the PCM device.
1008 void amdtp_stream_pcm_abort(struct amdtp_stream *s)
1010 struct snd_pcm_substream *pcm;
1012 pcm = ACCESS_ONCE(s->pcm);
1014 snd_pcm_stop_xrun(pcm);
1016 EXPORT_SYMBOL(amdtp_stream_pcm_abort);