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 * Nominally 3125 bytes/second, but the MIDI port's clock might be
26 * 1% too slow, and the bus clock 100 ppm too fast.
28 #define MIDI_BYTES_PER_SECOND 3093
31 * Several devices look only at the first eight data blocks.
32 * In any case, this is more than enough for the MIDI data rate.
34 #define MAX_MIDI_RX_BLOCKS 8
36 #define TRANSFER_DELAY_TICKS 0x2e00 /* 479.17 microseconds */
38 /* isochronous header parameters */
39 #define ISO_DATA_LENGTH_SHIFT 16
42 /* common isochronous packet header parameters */
43 #define CIP_EOH_SHIFT 31
44 #define CIP_EOH (1u << CIP_EOH_SHIFT)
45 #define CIP_EOH_MASK 0x80000000
46 #define CIP_SID_SHIFT 24
47 #define CIP_SID_MASK 0x3f000000
48 #define CIP_DBS_MASK 0x00ff0000
49 #define CIP_DBS_SHIFT 16
50 #define CIP_DBC_MASK 0x000000ff
51 #define CIP_FMT_SHIFT 24
52 #define CIP_FMT_MASK 0x3f000000
53 #define CIP_FDF_MASK 0x00ff0000
54 #define CIP_FDF_SHIFT 16
55 #define CIP_SYT_MASK 0x0000ffff
56 #define CIP_SYT_NO_INFO 0xffff
59 * Audio and Music transfer protocol specific parameters
60 * only "Clock-based rate control mode" is supported
62 #define CIP_FMT_AM (0x10 << CIP_FMT_SHIFT)
63 #define AMDTP_FDF_AM824 (0 << (CIP_FDF_SHIFT + 3))
64 #define AMDTP_FDF_NO_DATA 0xff
66 /* TODO: make these configurable */
67 #define INTERRUPT_INTERVAL 16
68 #define QUEUE_LENGTH 48
70 #define IN_PACKET_HEADER_SIZE 4
71 #define OUT_PACKET_HEADER_SIZE 0
73 static void pcm_period_tasklet(unsigned long data);
76 * amdtp_stream_init - initialize an AMDTP stream structure
77 * @s: the AMDTP stream to initialize
78 * @unit: the target of the stream
79 * @dir: the direction of stream
80 * @flags: the packet transmission method to use
82 int amdtp_stream_init(struct amdtp_stream *s, struct fw_unit *unit,
83 enum amdtp_stream_direction dir, enum cip_flags flags)
88 s->context = ERR_PTR(-1);
89 mutex_init(&s->mutex);
90 tasklet_init(&s->period_tasklet, pcm_period_tasklet, (unsigned long)s);
93 init_waitqueue_head(&s->callback_wait);
94 s->callbacked = false;
99 EXPORT_SYMBOL(amdtp_stream_init);
102 * amdtp_stream_destroy - free stream resources
103 * @s: the AMDTP stream to destroy
105 void amdtp_stream_destroy(struct amdtp_stream *s)
107 WARN_ON(amdtp_stream_running(s));
108 mutex_destroy(&s->mutex);
110 EXPORT_SYMBOL(amdtp_stream_destroy);
112 const unsigned int amdtp_syt_intervals[CIP_SFC_COUNT] = {
116 [CIP_SFC_88200] = 16,
117 [CIP_SFC_96000] = 16,
118 [CIP_SFC_176400] = 32,
119 [CIP_SFC_192000] = 32,
121 EXPORT_SYMBOL(amdtp_syt_intervals);
123 const unsigned int amdtp_rate_table[CIP_SFC_COUNT] = {
124 [CIP_SFC_32000] = 32000,
125 [CIP_SFC_44100] = 44100,
126 [CIP_SFC_48000] = 48000,
127 [CIP_SFC_88200] = 88200,
128 [CIP_SFC_96000] = 96000,
129 [CIP_SFC_176400] = 176400,
130 [CIP_SFC_192000] = 192000,
132 EXPORT_SYMBOL(amdtp_rate_table);
135 * amdtp_stream_add_pcm_hw_constraints - add hw constraints for PCM substream
136 * @s: the AMDTP stream, which must be initialized.
137 * @runtime: the PCM substream runtime
139 int amdtp_stream_add_pcm_hw_constraints(struct amdtp_stream *s,
140 struct snd_pcm_runtime *runtime)
144 /* AM824 in IEC 61883-6 can deliver 24bit data */
145 err = snd_pcm_hw_constraint_msbits(runtime, 0, 32, 24);
150 * Currently firewire-lib processes 16 packets in one software
151 * interrupt callback. This equals to 2msec but actually the
152 * interval of the interrupts has a jitter.
153 * Additionally, even if adding a constraint to fit period size to
154 * 2msec, actual calculated frames per period doesn't equal to 2msec,
155 * depending on sampling rate.
156 * Anyway, the interval to call snd_pcm_period_elapsed() cannot 2msec.
157 * Here let us use 5msec for safe period interrupt.
159 err = snd_pcm_hw_constraint_minmax(runtime,
160 SNDRV_PCM_HW_PARAM_PERIOD_TIME,
165 /* Non-Blocking stream has no more constraints */
166 if (!(s->flags & CIP_BLOCKING))
170 * One AMDTP packet can include some frames. In blocking mode, the
171 * number equals to SYT_INTERVAL. So the number is 8, 16 or 32,
172 * depending on its sampling rate. For accurate period interrupt, it's
173 * preferrable to align period/buffer sizes to current SYT_INTERVAL.
175 * TODO: These constraints can be improved with proper rules.
176 * Currently apply LCM of SYT_INTERVALs.
178 err = snd_pcm_hw_constraint_step(runtime, 0,
179 SNDRV_PCM_HW_PARAM_PERIOD_SIZE, 32);
182 err = snd_pcm_hw_constraint_step(runtime, 0,
183 SNDRV_PCM_HW_PARAM_BUFFER_SIZE, 32);
187 EXPORT_SYMBOL(amdtp_stream_add_pcm_hw_constraints);
190 * amdtp_stream_set_parameters - set stream parameters
191 * @s: the AMDTP stream to configure
192 * @rate: the sample rate
193 * @pcm_channels: the number of PCM samples in each data block, to be encoded
194 * as AM824 multi-bit linear audio
195 * @midi_ports: the number of MIDI ports (i.e., MPX-MIDI Data Channels)
197 * The parameters must be set before the stream is started, and must not be
198 * changed while the stream is running.
200 void amdtp_stream_set_parameters(struct amdtp_stream *s,
202 unsigned int pcm_channels,
203 unsigned int midi_ports)
205 unsigned int i, sfc, midi_channels;
207 midi_channels = DIV_ROUND_UP(midi_ports, 8);
209 if (WARN_ON(amdtp_stream_running(s)) |
210 WARN_ON(pcm_channels > AMDTP_MAX_CHANNELS_FOR_PCM) |
211 WARN_ON(midi_channels > AMDTP_MAX_CHANNELS_FOR_MIDI))
214 for (sfc = 0; sfc < ARRAY_SIZE(amdtp_rate_table); ++sfc)
215 if (amdtp_rate_table[sfc] == rate)
221 s->pcm_channels = pcm_channels;
223 s->data_block_quadlets = s->pcm_channels + midi_channels;
224 s->midi_ports = midi_ports;
226 s->syt_interval = amdtp_syt_intervals[sfc];
228 /* default buffering in the device */
229 s->transfer_delay = TRANSFER_DELAY_TICKS - TICKS_PER_CYCLE;
230 if (s->flags & CIP_BLOCKING)
231 /* additional buffering needed to adjust for no-data packets */
232 s->transfer_delay += TICKS_PER_SECOND * s->syt_interval / rate;
234 /* init the position map for PCM and MIDI channels */
235 for (i = 0; i < pcm_channels; i++)
236 s->pcm_positions[i] = i;
237 s->midi_position = s->pcm_channels;
240 * We do not know the actual MIDI FIFO size of most devices. Just
241 * assume two bytes, i.e., one byte can be received over the bus while
242 * the previous one is transmitted over MIDI.
243 * (The value here is adjusted for midi_ratelimit_per_packet().)
245 s->midi_fifo_limit = rate - MIDI_BYTES_PER_SECOND * s->syt_interval + 1;
247 EXPORT_SYMBOL(amdtp_stream_set_parameters);
250 * amdtp_stream_get_max_payload - get the stream's packet size
251 * @s: the AMDTP stream
253 * This function must not be called before the stream has been configured
254 * with amdtp_stream_set_parameters().
256 unsigned int amdtp_stream_get_max_payload(struct amdtp_stream *s)
258 unsigned int multiplier = 1;
260 if (s->flags & CIP_JUMBO_PAYLOAD)
263 return 8 + s->syt_interval * s->data_block_quadlets * 4 * multiplier;
265 EXPORT_SYMBOL(amdtp_stream_get_max_payload);
267 static void write_pcm_s16(struct amdtp_stream *s,
268 struct snd_pcm_substream *pcm,
269 __be32 *buffer, unsigned int frames);
270 static void write_pcm_s32(struct amdtp_stream *s,
271 struct snd_pcm_substream *pcm,
272 __be32 *buffer, unsigned int frames);
273 static void read_pcm_s32(struct amdtp_stream *s,
274 struct snd_pcm_substream *pcm,
275 __be32 *buffer, unsigned int frames);
278 * amdtp_stream_set_pcm_format - set the PCM format
279 * @s: the AMDTP stream to configure
280 * @format: the format of the ALSA PCM device
282 * The sample format must be set after the other parameters (rate/PCM channels/
283 * MIDI) and before the stream is started, and must not be changed while the
286 void amdtp_stream_set_pcm_format(struct amdtp_stream *s,
287 snd_pcm_format_t format)
289 if (WARN_ON(amdtp_stream_pcm_running(s)))
296 case SNDRV_PCM_FORMAT_S16:
297 if (s->direction == AMDTP_OUT_STREAM) {
298 s->transfer_samples = write_pcm_s16;
303 case SNDRV_PCM_FORMAT_S32:
304 if (s->direction == AMDTP_OUT_STREAM)
305 s->transfer_samples = write_pcm_s32;
307 s->transfer_samples = read_pcm_s32;
311 EXPORT_SYMBOL(amdtp_stream_set_pcm_format);
314 * amdtp_stream_pcm_prepare - prepare PCM device for running
315 * @s: the AMDTP stream
317 * This function should be called from the PCM device's .prepare callback.
319 void amdtp_stream_pcm_prepare(struct amdtp_stream *s)
321 tasklet_kill(&s->period_tasklet);
322 s->pcm_buffer_pointer = 0;
323 s->pcm_period_pointer = 0;
324 s->pointer_flush = true;
326 EXPORT_SYMBOL(amdtp_stream_pcm_prepare);
328 static unsigned int calculate_data_blocks(struct amdtp_stream *s,
331 unsigned int phase, data_blocks;
334 if (s->flags & CIP_BLOCKING) {
335 /* This module generate empty packet for 'no data'. */
336 if (syt == CIP_SYT_NO_INFO)
339 data_blocks = s->syt_interval;
340 /* Non-blocking mode. */
342 if (!cip_sfc_is_base_44100(s->sfc)) {
343 /* Sample_rate / 8000 is an integer, and precomputed. */
344 data_blocks = s->data_block_state;
346 phase = s->data_block_state;
349 * This calculates the number of data blocks per packet so that
350 * 1) the overall rate is correct and exactly synchronized to
352 * 2) packets with a rounded-up number of blocks occur as early
353 * as possible in the sequence (to prevent underruns of the
356 if (s->sfc == CIP_SFC_44100)
357 /* 6 6 5 6 5 6 5 ... */
358 data_blocks = 5 + ((phase & 1) ^
359 (phase == 0 || phase >= 40));
361 /* 12 11 11 11 11 ... or 23 22 22 22 22 ... */
362 data_blocks = 11 * (s->sfc >> 1) + (phase == 0);
363 if (++phase >= (80 >> (s->sfc >> 1)))
365 s->data_block_state = phase;
372 static unsigned int calculate_syt(struct amdtp_stream *s,
375 unsigned int syt_offset, phase, index, syt;
377 if (s->last_syt_offset < TICKS_PER_CYCLE) {
378 if (!cip_sfc_is_base_44100(s->sfc))
379 syt_offset = s->last_syt_offset + s->syt_offset_state;
382 * The time, in ticks, of the n'th SYT_INTERVAL sample is:
383 * n * SYT_INTERVAL * 24576000 / sample_rate
384 * Modulo TICKS_PER_CYCLE, the difference between successive
385 * elements is about 1386.23. Rounding the results of this
386 * formula to the SYT precision results in a sequence of
387 * differences that begins with:
388 * 1386 1386 1387 1386 1386 1386 1387 1386 1386 1386 1387 ...
389 * This code generates _exactly_ the same sequence.
391 phase = s->syt_offset_state;
393 syt_offset = s->last_syt_offset;
394 syt_offset += 1386 + ((index && !(index & 3)) ||
398 s->syt_offset_state = phase;
401 syt_offset = s->last_syt_offset - TICKS_PER_CYCLE;
402 s->last_syt_offset = syt_offset;
404 if (syt_offset < TICKS_PER_CYCLE) {
405 syt_offset += s->transfer_delay;
406 syt = (cycle + syt_offset / TICKS_PER_CYCLE) << 12;
407 syt += syt_offset % TICKS_PER_CYCLE;
409 return syt & CIP_SYT_MASK;
411 return CIP_SYT_NO_INFO;
415 static void write_pcm_s32(struct amdtp_stream *s,
416 struct snd_pcm_substream *pcm,
417 __be32 *buffer, unsigned int frames)
419 struct snd_pcm_runtime *runtime = pcm->runtime;
420 unsigned int channels, remaining_frames, i, c;
423 channels = s->pcm_channels;
424 src = (void *)runtime->dma_area +
425 frames_to_bytes(runtime, s->pcm_buffer_pointer);
426 remaining_frames = runtime->buffer_size - s->pcm_buffer_pointer;
428 for (i = 0; i < frames; ++i) {
429 for (c = 0; c < channels; ++c) {
430 buffer[s->pcm_positions[c]] =
431 cpu_to_be32((*src >> 8) | 0x40000000);
434 buffer += s->data_block_quadlets;
435 if (--remaining_frames == 0)
436 src = (void *)runtime->dma_area;
440 static void write_pcm_s16(struct amdtp_stream *s,
441 struct snd_pcm_substream *pcm,
442 __be32 *buffer, unsigned int frames)
444 struct snd_pcm_runtime *runtime = pcm->runtime;
445 unsigned int channels, remaining_frames, i, c;
448 channels = s->pcm_channels;
449 src = (void *)runtime->dma_area +
450 frames_to_bytes(runtime, s->pcm_buffer_pointer);
451 remaining_frames = runtime->buffer_size - s->pcm_buffer_pointer;
453 for (i = 0; i < frames; ++i) {
454 for (c = 0; c < channels; ++c) {
455 buffer[s->pcm_positions[c]] =
456 cpu_to_be32((*src << 8) | 0x42000000);
459 buffer += s->data_block_quadlets;
460 if (--remaining_frames == 0)
461 src = (void *)runtime->dma_area;
465 static void read_pcm_s32(struct amdtp_stream *s,
466 struct snd_pcm_substream *pcm,
467 __be32 *buffer, unsigned int frames)
469 struct snd_pcm_runtime *runtime = pcm->runtime;
470 unsigned int channels, remaining_frames, i, c;
473 channels = s->pcm_channels;
474 dst = (void *)runtime->dma_area +
475 frames_to_bytes(runtime, s->pcm_buffer_pointer);
476 remaining_frames = runtime->buffer_size - s->pcm_buffer_pointer;
478 for (i = 0; i < frames; ++i) {
479 for (c = 0; c < channels; ++c) {
480 *dst = be32_to_cpu(buffer[s->pcm_positions[c]]) << 8;
483 buffer += s->data_block_quadlets;
484 if (--remaining_frames == 0)
485 dst = (void *)runtime->dma_area;
489 static void write_pcm_silence(struct amdtp_stream *s,
490 __be32 *buffer, unsigned int frames)
494 for (i = 0; i < frames; ++i) {
495 for (c = 0; c < s->pcm_channels; ++c)
496 buffer[s->pcm_positions[c]] = cpu_to_be32(0x40000000);
497 buffer += s->data_block_quadlets;
502 * To avoid sending MIDI bytes at too high a rate, assume that the receiving
503 * device has a FIFO, and track how much it is filled. This values increases
504 * by one whenever we send one byte in a packet, but the FIFO empties at
505 * a constant rate independent of our packet rate. One packet has syt_interval
506 * samples, so the number of bytes that empty out of the FIFO, per packet(!),
507 * is MIDI_BYTES_PER_SECOND * syt_interval / sample_rate. To avoid storing
508 * fractional values, the values in midi_fifo_used[] are measured in bytes
509 * multiplied by the sample rate.
511 static bool midi_ratelimit_per_packet(struct amdtp_stream *s, unsigned int port)
515 used = s->midi_fifo_used[port];
516 if (used == 0) /* common shortcut */
519 used -= MIDI_BYTES_PER_SECOND * s->syt_interval;
521 s->midi_fifo_used[port] = used;
523 return used < s->midi_fifo_limit;
526 static void midi_rate_use_one_byte(struct amdtp_stream *s, unsigned int port)
528 s->midi_fifo_used[port] += amdtp_rate_table[s->sfc];
531 static void write_midi_messages(struct amdtp_stream *s,
532 __be32 *buffer, unsigned int frames)
534 unsigned int f, port;
537 for (f = 0; f < frames; f++) {
538 b = (u8 *)&buffer[s->midi_position];
540 port = (s->data_block_counter + f) % 8;
541 if (f < MAX_MIDI_RX_BLOCKS &&
542 midi_ratelimit_per_packet(s, port) &&
543 s->midi[port] != NULL &&
544 snd_rawmidi_transmit(s->midi[port], &b[1], 1) == 1) {
545 midi_rate_use_one_byte(s, port);
554 buffer += s->data_block_quadlets;
558 static void read_midi_messages(struct amdtp_stream *s,
559 __be32 *buffer, unsigned int frames)
561 unsigned int f, port;
565 for (f = 0; f < frames; f++) {
566 port = (s->data_block_counter + f) % 8;
567 b = (u8 *)&buffer[s->midi_position];
570 if ((1 <= len) && (len <= 3) && (s->midi[port]))
571 snd_rawmidi_receive(s->midi[port], b + 1, len);
573 buffer += s->data_block_quadlets;
577 static void update_pcm_pointers(struct amdtp_stream *s,
578 struct snd_pcm_substream *pcm,
584 * In IEC 61883-6, one data block represents one event. In ALSA, one
585 * event equals to one PCM frame. But Dice has a quirk to transfer
586 * two PCM frames in one data block.
588 if (s->double_pcm_frames)
591 ptr = s->pcm_buffer_pointer + frames;
592 if (ptr >= pcm->runtime->buffer_size)
593 ptr -= pcm->runtime->buffer_size;
594 ACCESS_ONCE(s->pcm_buffer_pointer) = ptr;
596 s->pcm_period_pointer += frames;
597 if (s->pcm_period_pointer >= pcm->runtime->period_size) {
598 s->pcm_period_pointer -= pcm->runtime->period_size;
599 s->pointer_flush = false;
600 tasklet_hi_schedule(&s->period_tasklet);
604 static void pcm_period_tasklet(unsigned long data)
606 struct amdtp_stream *s = (void *)data;
607 struct snd_pcm_substream *pcm = ACCESS_ONCE(s->pcm);
610 snd_pcm_period_elapsed(pcm);
613 static int queue_packet(struct amdtp_stream *s,
614 unsigned int header_length,
615 unsigned int payload_length, bool skip)
617 struct fw_iso_packet p = {0};
620 if (IS_ERR(s->context))
623 p.interrupt = IS_ALIGNED(s->packet_index + 1, INTERRUPT_INTERVAL);
625 p.header_length = header_length;
626 p.payload_length = (!skip) ? payload_length : 0;
628 err = fw_iso_context_queue(s->context, &p, &s->buffer.iso_buffer,
629 s->buffer.packets[s->packet_index].offset);
631 dev_err(&s->unit->device, "queueing error: %d\n", err);
635 if (++s->packet_index >= QUEUE_LENGTH)
641 static inline int queue_out_packet(struct amdtp_stream *s,
642 unsigned int payload_length, bool skip)
644 return queue_packet(s, OUT_PACKET_HEADER_SIZE,
645 payload_length, skip);
648 static inline int queue_in_packet(struct amdtp_stream *s)
650 return queue_packet(s, IN_PACKET_HEADER_SIZE,
651 amdtp_stream_get_max_payload(s), false);
654 static int handle_out_packet(struct amdtp_stream *s, unsigned int data_blocks,
658 unsigned int payload_length;
659 struct snd_pcm_substream *pcm;
661 buffer = s->buffer.packets[s->packet_index].buffer;
662 buffer[0] = cpu_to_be32(ACCESS_ONCE(s->source_node_id_field) |
663 (s->data_block_quadlets << CIP_DBS_SHIFT) |
664 s->data_block_counter);
665 buffer[1] = cpu_to_be32(CIP_EOH | CIP_FMT_AM | AMDTP_FDF_AM824 |
666 (s->sfc << CIP_FDF_SHIFT) | syt);
669 pcm = ACCESS_ONCE(s->pcm);
671 s->transfer_samples(s, pcm, buffer, data_blocks);
673 write_pcm_silence(s, buffer, data_blocks);
675 write_midi_messages(s, buffer, data_blocks);
677 s->data_block_counter = (s->data_block_counter + data_blocks) & 0xff;
679 payload_length = 8 + data_blocks * 4 * s->data_block_quadlets;
680 if (queue_out_packet(s, payload_length, false) < 0)
684 update_pcm_pointers(s, pcm, data_blocks);
686 /* No need to return the number of handled data blocks. */
690 static int handle_in_packet(struct amdtp_stream *s,
691 unsigned int payload_quadlets, __be32 *buffer,
692 unsigned int *data_blocks)
695 unsigned int data_block_quadlets, data_block_counter, dbc_interval;
696 struct snd_pcm_substream *pcm = NULL;
699 cip_header[0] = be32_to_cpu(buffer[0]);
700 cip_header[1] = be32_to_cpu(buffer[1]);
703 * This module supports 'Two-quadlet CIP header with SYT field'.
704 * For convenience, also check FMT field is AM824 or not.
706 if (((cip_header[0] & CIP_EOH_MASK) == CIP_EOH) ||
707 ((cip_header[1] & CIP_EOH_MASK) != CIP_EOH) ||
708 ((cip_header[1] & CIP_FMT_MASK) != CIP_FMT_AM)) {
709 dev_info_ratelimited(&s->unit->device,
710 "Invalid CIP header for AMDTP: %08X:%08X\n",
711 cip_header[0], cip_header[1]);
716 /* Calculate data blocks */
717 if (payload_quadlets < 3 ||
718 ((cip_header[1] & CIP_FDF_MASK) ==
719 (AMDTP_FDF_NO_DATA << CIP_FDF_SHIFT))) {
722 data_block_quadlets =
723 (cip_header[0] & CIP_DBS_MASK) >> CIP_DBS_SHIFT;
724 /* avoid division by zero */
725 if (data_block_quadlets == 0) {
726 dev_err(&s->unit->device,
727 "Detect invalid value in dbs field: %08X\n",
731 if (s->flags & CIP_WRONG_DBS)
732 data_block_quadlets = s->data_block_quadlets;
734 *data_blocks = (payload_quadlets - 2) / data_block_quadlets;
737 /* Check data block counter continuity */
738 data_block_counter = cip_header[0] & CIP_DBC_MASK;
739 if (*data_blocks == 0 && (s->flags & CIP_EMPTY_HAS_WRONG_DBC) &&
740 s->data_block_counter != UINT_MAX)
741 data_block_counter = s->data_block_counter;
743 if (((s->flags & CIP_SKIP_DBC_ZERO_CHECK) &&
744 data_block_counter == s->tx_first_dbc) ||
745 s->data_block_counter == UINT_MAX) {
747 } else if (!(s->flags & CIP_DBC_IS_END_EVENT)) {
748 lost = data_block_counter != s->data_block_counter;
750 if ((*data_blocks > 0) && (s->tx_dbc_interval > 0))
751 dbc_interval = s->tx_dbc_interval;
753 dbc_interval = *data_blocks;
755 lost = data_block_counter !=
756 ((s->data_block_counter + dbc_interval) & 0xff);
760 dev_err(&s->unit->device,
761 "Detect discontinuity of CIP: %02X %02X\n",
762 s->data_block_counter, data_block_counter);
766 if (*data_blocks > 0) {
769 pcm = ACCESS_ONCE(s->pcm);
771 s->transfer_samples(s, pcm, buffer, *data_blocks);
774 read_midi_messages(s, buffer, *data_blocks);
777 if (s->flags & CIP_DBC_IS_END_EVENT)
778 s->data_block_counter = data_block_counter;
780 s->data_block_counter =
781 (data_block_counter + *data_blocks) & 0xff;
783 if (queue_in_packet(s) < 0)
787 update_pcm_pointers(s, pcm, *data_blocks);
792 static void out_stream_callback(struct fw_iso_context *context, u32 cycle,
793 size_t header_length, void *header,
796 struct amdtp_stream *s = private_data;
797 unsigned int i, syt, packets = header_length / 4;
798 unsigned int data_blocks;
800 if (s->packet_index < 0)
804 * Compute the cycle of the last queued packet.
805 * (We need only the four lowest bits for the SYT, so we can ignore
806 * that bits 0-11 must wrap around at 3072.)
808 cycle += QUEUE_LENGTH - packets;
810 for (i = 0; i < packets; ++i) {
811 syt = calculate_syt(s, ++cycle);
812 data_blocks = calculate_data_blocks(s, syt);
814 if (handle_out_packet(s, data_blocks, syt) < 0) {
815 s->packet_index = -1;
816 amdtp_stream_pcm_abort(s);
821 fw_iso_context_queue_flush(s->context);
824 static void in_stream_callback(struct fw_iso_context *context, u32 cycle,
825 size_t header_length, void *header,
828 struct amdtp_stream *s = private_data;
829 unsigned int p, syt, packets;
830 unsigned int payload_quadlets, max_payload_quadlets;
831 unsigned int data_blocks;
832 __be32 *buffer, *headers = header;
834 if (s->packet_index < 0)
837 /* The number of packets in buffer */
838 packets = header_length / IN_PACKET_HEADER_SIZE;
840 /* For buffer-over-run prevention. */
841 max_payload_quadlets = amdtp_stream_get_max_payload(s) / 4;
843 for (p = 0; p < packets; p++) {
844 buffer = s->buffer.packets[s->packet_index].buffer;
846 /* The number of quadlets in this packet */
848 (be32_to_cpu(headers[p]) >> ISO_DATA_LENGTH_SHIFT) / 4;
849 if (payload_quadlets > max_payload_quadlets) {
850 dev_err(&s->unit->device,
851 "Detect jumbo payload: %02x %02x\n",
852 payload_quadlets, max_payload_quadlets);
853 s->packet_index = -1;
857 if (handle_in_packet(s, payload_quadlets, buffer,
859 s->packet_index = -1;
863 /* Process sync slave stream */
864 if (s->sync_slave && s->sync_slave->callbacked) {
865 syt = be32_to_cpu(buffer[1]) & CIP_SYT_MASK;
866 if (handle_out_packet(s->sync_slave,
867 data_blocks, syt) < 0) {
868 s->packet_index = -1;
874 /* Queueing error or detecting discontinuity */
875 if (s->packet_index < 0) {
876 amdtp_stream_pcm_abort(s);
878 /* Abort sync slave. */
880 s->sync_slave->packet_index = -1;
881 amdtp_stream_pcm_abort(s->sync_slave);
886 /* when sync to device, flush the packets for slave stream */
887 if (s->sync_slave && s->sync_slave->callbacked)
888 fw_iso_context_queue_flush(s->sync_slave->context);
890 fw_iso_context_queue_flush(s->context);
893 /* processing is done by master callback */
894 static void slave_stream_callback(struct fw_iso_context *context, u32 cycle,
895 size_t header_length, void *header,
901 /* this is executed one time */
902 static void amdtp_stream_first_callback(struct fw_iso_context *context,
903 u32 cycle, size_t header_length,
904 void *header, void *private_data)
906 struct amdtp_stream *s = private_data;
909 * For in-stream, first packet has come.
910 * For out-stream, prepared to transmit first packet
912 s->callbacked = true;
913 wake_up(&s->callback_wait);
915 if (s->direction == AMDTP_IN_STREAM)
916 context->callback.sc = in_stream_callback;
917 else if (s->flags & CIP_SYNC_TO_DEVICE)
918 context->callback.sc = slave_stream_callback;
920 context->callback.sc = out_stream_callback;
922 context->callback.sc(context, cycle, header_length, header, s);
926 * amdtp_stream_start - start transferring packets
927 * @s: the AMDTP stream to start
928 * @channel: the isochronous channel on the bus
929 * @speed: firewire speed code
931 * The stream cannot be started until it has been configured with
932 * amdtp_stream_set_parameters() and it must be started before any PCM or MIDI
933 * device can be started.
935 int amdtp_stream_start(struct amdtp_stream *s, int channel, int speed)
937 static const struct {
938 unsigned int data_block;
939 unsigned int syt_offset;
940 } initial_state[] = {
941 [CIP_SFC_32000] = { 4, 3072 },
942 [CIP_SFC_48000] = { 6, 1024 },
943 [CIP_SFC_96000] = { 12, 1024 },
944 [CIP_SFC_192000] = { 24, 1024 },
945 [CIP_SFC_44100] = { 0, 67 },
946 [CIP_SFC_88200] = { 0, 67 },
947 [CIP_SFC_176400] = { 0, 67 },
949 unsigned int header_size;
950 enum dma_data_direction dir;
953 mutex_lock(&s->mutex);
955 if (WARN_ON(amdtp_stream_running(s) ||
956 (s->data_block_quadlets < 1))) {
961 if (s->direction == AMDTP_IN_STREAM &&
962 s->flags & CIP_SKIP_INIT_DBC_CHECK)
963 s->data_block_counter = UINT_MAX;
965 s->data_block_counter = 0;
966 s->data_block_state = initial_state[s->sfc].data_block;
967 s->syt_offset_state = initial_state[s->sfc].syt_offset;
968 s->last_syt_offset = TICKS_PER_CYCLE;
970 /* initialize packet buffer */
971 if (s->direction == AMDTP_IN_STREAM) {
972 dir = DMA_FROM_DEVICE;
973 type = FW_ISO_CONTEXT_RECEIVE;
974 header_size = IN_PACKET_HEADER_SIZE;
977 type = FW_ISO_CONTEXT_TRANSMIT;
978 header_size = OUT_PACKET_HEADER_SIZE;
980 err = iso_packets_buffer_init(&s->buffer, s->unit, QUEUE_LENGTH,
981 amdtp_stream_get_max_payload(s), dir);
985 s->context = fw_iso_context_create(fw_parent_device(s->unit)->card,
986 type, channel, speed, header_size,
987 amdtp_stream_first_callback, s);
988 if (IS_ERR(s->context)) {
989 err = PTR_ERR(s->context);
991 dev_err(&s->unit->device,
992 "no free stream on this controller\n");
996 amdtp_stream_update(s);
1000 if (s->direction == AMDTP_IN_STREAM)
1001 err = queue_in_packet(s);
1003 err = queue_out_packet(s, 0, true);
1006 } while (s->packet_index > 0);
1008 /* NOTE: TAG1 matches CIP. This just affects in stream. */
1009 tag = FW_ISO_CONTEXT_MATCH_TAG1;
1010 if (s->flags & CIP_EMPTY_WITH_TAG0)
1011 tag |= FW_ISO_CONTEXT_MATCH_TAG0;
1013 s->callbacked = false;
1014 err = fw_iso_context_start(s->context, -1, 0, tag);
1018 mutex_unlock(&s->mutex);
1023 fw_iso_context_destroy(s->context);
1024 s->context = ERR_PTR(-1);
1026 iso_packets_buffer_destroy(&s->buffer, s->unit);
1028 mutex_unlock(&s->mutex);
1032 EXPORT_SYMBOL(amdtp_stream_start);
1035 * amdtp_stream_pcm_pointer - get the PCM buffer position
1036 * @s: the AMDTP stream that transports the PCM data
1038 * Returns the current buffer position, in frames.
1040 unsigned long amdtp_stream_pcm_pointer(struct amdtp_stream *s)
1042 /* this optimization is allowed to be racy */
1043 if (s->pointer_flush && amdtp_stream_running(s))
1044 fw_iso_context_flush_completions(s->context);
1046 s->pointer_flush = true;
1048 return ACCESS_ONCE(s->pcm_buffer_pointer);
1050 EXPORT_SYMBOL(amdtp_stream_pcm_pointer);
1053 * amdtp_stream_update - update the stream after a bus reset
1054 * @s: the AMDTP stream
1056 void amdtp_stream_update(struct amdtp_stream *s)
1059 ACCESS_ONCE(s->source_node_id_field) =
1060 (fw_parent_device(s->unit)->card->node_id << CIP_SID_SHIFT) &
1063 EXPORT_SYMBOL(amdtp_stream_update);
1066 * amdtp_stream_stop - stop sending packets
1067 * @s: the AMDTP stream to stop
1069 * All PCM and MIDI devices of the stream must be stopped before the stream
1070 * itself can be stopped.
1072 void amdtp_stream_stop(struct amdtp_stream *s)
1074 mutex_lock(&s->mutex);
1076 if (!amdtp_stream_running(s)) {
1077 mutex_unlock(&s->mutex);
1081 tasklet_kill(&s->period_tasklet);
1082 fw_iso_context_stop(s->context);
1083 fw_iso_context_destroy(s->context);
1084 s->context = ERR_PTR(-1);
1085 iso_packets_buffer_destroy(&s->buffer, s->unit);
1087 s->callbacked = false;
1089 mutex_unlock(&s->mutex);
1091 EXPORT_SYMBOL(amdtp_stream_stop);
1094 * amdtp_stream_pcm_abort - abort the running PCM device
1095 * @s: the AMDTP stream about to be stopped
1097 * If the isochronous stream needs to be stopped asynchronously, call this
1098 * function first to stop the PCM device.
1100 void amdtp_stream_pcm_abort(struct amdtp_stream *s)
1102 struct snd_pcm_substream *pcm;
1104 pcm = ACCESS_ONCE(s->pcm);
1106 snd_pcm_stop_xrun(pcm);
1108 EXPORT_SYMBOL(amdtp_stream_pcm_abort);