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 <sound/pcm.h>
15 #include <sound/pcm_params.h>
16 #include "amdtp-stream.h"
18 #define TICKS_PER_CYCLE 3072
19 #define CYCLES_PER_SECOND 8000
20 #define TICKS_PER_SECOND (TICKS_PER_CYCLE * CYCLES_PER_SECOND)
22 /* Always support Linux tracing subsystem. */
23 #define CREATE_TRACE_POINTS
24 #include "amdtp-stream-trace.h"
26 #define TRANSFER_DELAY_TICKS 0x2e00 /* 479.17 microseconds */
28 /* isochronous header parameters */
29 #define ISO_DATA_LENGTH_SHIFT 16
32 /* common isochronous packet header parameters */
33 #define CIP_EOH_SHIFT 31
34 #define CIP_EOH (1u << CIP_EOH_SHIFT)
35 #define CIP_EOH_MASK 0x80000000
36 #define CIP_SID_SHIFT 24
37 #define CIP_SID_MASK 0x3f000000
38 #define CIP_DBS_MASK 0x00ff0000
39 #define CIP_DBS_SHIFT 16
40 #define CIP_DBC_MASK 0x000000ff
41 #define CIP_FMT_SHIFT 24
42 #define CIP_FMT_MASK 0x3f000000
43 #define CIP_FDF_MASK 0x00ff0000
44 #define CIP_FDF_SHIFT 16
45 #define CIP_SYT_MASK 0x0000ffff
46 #define CIP_SYT_NO_INFO 0xffff
48 /* Audio and Music transfer protocol specific parameters */
49 #define CIP_FMT_AM 0x10
50 #define AMDTP_FDF_NO_DATA 0xff
52 /* TODO: make these configurable */
53 #define INTERRUPT_INTERVAL 16
54 #define QUEUE_LENGTH 48
56 #define IN_PACKET_HEADER_SIZE 4
57 #define OUT_PACKET_HEADER_SIZE 0
59 static void pcm_period_tasklet(unsigned long data);
62 * amdtp_stream_init - initialize an AMDTP stream structure
63 * @s: the AMDTP stream to initialize
64 * @unit: the target of the stream
65 * @dir: the direction of stream
66 * @flags: the packet transmission method to use
67 * @fmt: the value of fmt field in CIP header
68 * @process_data_blocks: callback handler to process data blocks
69 * @protocol_size: the size to allocate newly for protocol
71 int amdtp_stream_init(struct amdtp_stream *s, struct fw_unit *unit,
72 enum amdtp_stream_direction dir, enum cip_flags flags,
74 amdtp_stream_process_data_blocks_t process_data_blocks,
75 unsigned int protocol_size)
77 if (process_data_blocks == NULL)
80 s->protocol = kzalloc(protocol_size, GFP_KERNEL);
87 s->context = ERR_PTR(-1);
88 mutex_init(&s->mutex);
89 tasklet_init(&s->period_tasklet, pcm_period_tasklet, (unsigned long)s);
92 init_waitqueue_head(&s->callback_wait);
93 s->callbacked = false;
97 s->process_data_blocks = process_data_blocks;
101 EXPORT_SYMBOL(amdtp_stream_init);
104 * amdtp_stream_destroy - free stream resources
105 * @s: the AMDTP stream to destroy
107 void amdtp_stream_destroy(struct amdtp_stream *s)
109 /* Not initialized. */
110 if (s->protocol == NULL)
113 WARN_ON(amdtp_stream_running(s));
115 mutex_destroy(&s->mutex);
117 EXPORT_SYMBOL(amdtp_stream_destroy);
119 const unsigned int amdtp_syt_intervals[CIP_SFC_COUNT] = {
123 [CIP_SFC_88200] = 16,
124 [CIP_SFC_96000] = 16,
125 [CIP_SFC_176400] = 32,
126 [CIP_SFC_192000] = 32,
128 EXPORT_SYMBOL(amdtp_syt_intervals);
130 const unsigned int amdtp_rate_table[CIP_SFC_COUNT] = {
131 [CIP_SFC_32000] = 32000,
132 [CIP_SFC_44100] = 44100,
133 [CIP_SFC_48000] = 48000,
134 [CIP_SFC_88200] = 88200,
135 [CIP_SFC_96000] = 96000,
136 [CIP_SFC_176400] = 176400,
137 [CIP_SFC_192000] = 192000,
139 EXPORT_SYMBOL(amdtp_rate_table);
142 * amdtp_stream_add_pcm_hw_constraints - add hw constraints for PCM substream
143 * @s: the AMDTP stream, which must be initialized.
144 * @runtime: the PCM substream runtime
146 int amdtp_stream_add_pcm_hw_constraints(struct amdtp_stream *s,
147 struct snd_pcm_runtime *runtime)
152 * Currently firewire-lib processes 16 packets in one software
153 * interrupt callback. This equals to 2msec but actually the
154 * interval of the interrupts has a jitter.
155 * Additionally, even if adding a constraint to fit period size to
156 * 2msec, actual calculated frames per period doesn't equal to 2msec,
157 * depending on sampling rate.
158 * Anyway, the interval to call snd_pcm_period_elapsed() cannot 2msec.
159 * Here let us use 5msec for safe period interrupt.
161 err = snd_pcm_hw_constraint_minmax(runtime,
162 SNDRV_PCM_HW_PARAM_PERIOD_TIME,
167 /* Non-Blocking stream has no more constraints */
168 if (!(s->flags & CIP_BLOCKING))
172 * One AMDTP packet can include some frames. In blocking mode, the
173 * number equals to SYT_INTERVAL. So the number is 8, 16 or 32,
174 * depending on its sampling rate. For accurate period interrupt, it's
175 * preferrable to align period/buffer sizes to current SYT_INTERVAL.
177 * TODO: These constraints can be improved with proper rules.
178 * Currently apply LCM of SYT_INTERVALs.
180 err = snd_pcm_hw_constraint_step(runtime, 0,
181 SNDRV_PCM_HW_PARAM_PERIOD_SIZE, 32);
184 err = snd_pcm_hw_constraint_step(runtime, 0,
185 SNDRV_PCM_HW_PARAM_BUFFER_SIZE, 32);
189 EXPORT_SYMBOL(amdtp_stream_add_pcm_hw_constraints);
192 * amdtp_stream_set_parameters - set stream parameters
193 * @s: the AMDTP stream to configure
194 * @rate: the sample rate
195 * @data_block_quadlets: the size of a data block in quadlet unit
197 * The parameters must be set before the stream is started, and must not be
198 * changed while the stream is running.
200 int amdtp_stream_set_parameters(struct amdtp_stream *s, unsigned int rate,
201 unsigned int data_block_quadlets)
205 for (sfc = 0; sfc < ARRAY_SIZE(amdtp_rate_table); ++sfc) {
206 if (amdtp_rate_table[sfc] == rate)
209 if (sfc == ARRAY_SIZE(amdtp_rate_table))
213 s->data_block_quadlets = data_block_quadlets;
214 s->syt_interval = amdtp_syt_intervals[sfc];
216 /* default buffering in the device */
217 s->transfer_delay = TRANSFER_DELAY_TICKS - TICKS_PER_CYCLE;
218 if (s->flags & CIP_BLOCKING)
219 /* additional buffering needed to adjust for no-data packets */
220 s->transfer_delay += TICKS_PER_SECOND * s->syt_interval / rate;
224 EXPORT_SYMBOL(amdtp_stream_set_parameters);
227 * amdtp_stream_get_max_payload - get the stream's packet size
228 * @s: the AMDTP stream
230 * This function must not be called before the stream has been configured
231 * with amdtp_stream_set_parameters().
233 unsigned int amdtp_stream_get_max_payload(struct amdtp_stream *s)
235 unsigned int multiplier = 1;
237 if (s->flags & CIP_JUMBO_PAYLOAD)
240 return 8 + s->syt_interval * s->data_block_quadlets * 4 * multiplier;
242 EXPORT_SYMBOL(amdtp_stream_get_max_payload);
245 * amdtp_stream_pcm_prepare - prepare PCM device for running
246 * @s: the AMDTP stream
248 * This function should be called from the PCM device's .prepare callback.
250 void amdtp_stream_pcm_prepare(struct amdtp_stream *s)
252 tasklet_kill(&s->period_tasklet);
253 s->pcm_buffer_pointer = 0;
254 s->pcm_period_pointer = 0;
255 s->pointer_flush = true;
257 EXPORT_SYMBOL(amdtp_stream_pcm_prepare);
259 static unsigned int calculate_data_blocks(struct amdtp_stream *s,
262 unsigned int phase, data_blocks;
265 if (s->flags & CIP_BLOCKING) {
266 /* This module generate empty packet for 'no data'. */
267 if (syt == CIP_SYT_NO_INFO)
270 data_blocks = s->syt_interval;
271 /* Non-blocking mode. */
273 if (!cip_sfc_is_base_44100(s->sfc)) {
274 /* Sample_rate / 8000 is an integer, and precomputed. */
275 data_blocks = s->data_block_state;
277 phase = s->data_block_state;
280 * This calculates the number of data blocks per packet so that
281 * 1) the overall rate is correct and exactly synchronized to
283 * 2) packets with a rounded-up number of blocks occur as early
284 * as possible in the sequence (to prevent underruns of the
287 if (s->sfc == CIP_SFC_44100)
288 /* 6 6 5 6 5 6 5 ... */
289 data_blocks = 5 + ((phase & 1) ^
290 (phase == 0 || phase >= 40));
292 /* 12 11 11 11 11 ... or 23 22 22 22 22 ... */
293 data_blocks = 11 * (s->sfc >> 1) + (phase == 0);
294 if (++phase >= (80 >> (s->sfc >> 1)))
296 s->data_block_state = phase;
303 static unsigned int calculate_syt(struct amdtp_stream *s,
306 unsigned int syt_offset, phase, index, syt;
308 if (s->last_syt_offset < TICKS_PER_CYCLE) {
309 if (!cip_sfc_is_base_44100(s->sfc))
310 syt_offset = s->last_syt_offset + s->syt_offset_state;
313 * The time, in ticks, of the n'th SYT_INTERVAL sample is:
314 * n * SYT_INTERVAL * 24576000 / sample_rate
315 * Modulo TICKS_PER_CYCLE, the difference between successive
316 * elements is about 1386.23. Rounding the results of this
317 * formula to the SYT precision results in a sequence of
318 * differences that begins with:
319 * 1386 1386 1387 1386 1386 1386 1387 1386 1386 1386 1387 ...
320 * This code generates _exactly_ the same sequence.
322 phase = s->syt_offset_state;
324 syt_offset = s->last_syt_offset;
325 syt_offset += 1386 + ((index && !(index & 3)) ||
329 s->syt_offset_state = phase;
332 syt_offset = s->last_syt_offset - TICKS_PER_CYCLE;
333 s->last_syt_offset = syt_offset;
335 if (syt_offset < TICKS_PER_CYCLE) {
336 syt_offset += s->transfer_delay;
337 syt = (cycle + syt_offset / TICKS_PER_CYCLE) << 12;
338 syt += syt_offset % TICKS_PER_CYCLE;
340 return syt & CIP_SYT_MASK;
342 return CIP_SYT_NO_INFO;
346 static void update_pcm_pointers(struct amdtp_stream *s,
347 struct snd_pcm_substream *pcm,
352 ptr = s->pcm_buffer_pointer + frames;
353 if (ptr >= pcm->runtime->buffer_size)
354 ptr -= pcm->runtime->buffer_size;
355 ACCESS_ONCE(s->pcm_buffer_pointer) = ptr;
357 s->pcm_period_pointer += frames;
358 if (s->pcm_period_pointer >= pcm->runtime->period_size) {
359 s->pcm_period_pointer -= pcm->runtime->period_size;
360 s->pointer_flush = false;
361 tasklet_hi_schedule(&s->period_tasklet);
365 static void pcm_period_tasklet(unsigned long data)
367 struct amdtp_stream *s = (void *)data;
368 struct snd_pcm_substream *pcm = ACCESS_ONCE(s->pcm);
371 snd_pcm_period_elapsed(pcm);
374 static int queue_packet(struct amdtp_stream *s,
375 unsigned int header_length,
376 unsigned int payload_length, bool skip)
378 struct fw_iso_packet p = {0};
381 if (IS_ERR(s->context))
384 p.interrupt = IS_ALIGNED(s->packet_index + 1, INTERRUPT_INTERVAL);
386 p.header_length = header_length;
387 p.payload_length = (!skip) ? payload_length : 0;
389 err = fw_iso_context_queue(s->context, &p, &s->buffer.iso_buffer,
390 s->buffer.packets[s->packet_index].offset);
392 dev_err(&s->unit->device, "queueing error: %d\n", err);
396 if (++s->packet_index >= QUEUE_LENGTH)
402 static inline int queue_out_packet(struct amdtp_stream *s,
403 unsigned int payload_length, bool skip)
405 return queue_packet(s, OUT_PACKET_HEADER_SIZE,
406 payload_length, skip);
409 static inline int queue_in_packet(struct amdtp_stream *s)
411 return queue_packet(s, IN_PACKET_HEADER_SIZE,
412 amdtp_stream_get_max_payload(s), false);
415 static int handle_out_packet(struct amdtp_stream *s, unsigned int data_blocks,
416 unsigned int cycle, unsigned int syt)
419 unsigned int payload_length;
420 unsigned int pcm_frames;
421 struct snd_pcm_substream *pcm;
423 buffer = s->buffer.packets[s->packet_index].buffer;
424 pcm_frames = s->process_data_blocks(s, buffer + 2, data_blocks, &syt);
426 buffer[0] = cpu_to_be32(ACCESS_ONCE(s->source_node_id_field) |
427 (s->data_block_quadlets << CIP_DBS_SHIFT) |
428 s->data_block_counter);
429 buffer[1] = cpu_to_be32(CIP_EOH |
430 ((s->fmt << CIP_FMT_SHIFT) & CIP_FMT_MASK) |
431 ((s->fdf << CIP_FDF_SHIFT) & CIP_FDF_MASK) |
432 (syt & CIP_SYT_MASK));
434 s->data_block_counter = (s->data_block_counter + data_blocks) & 0xff;
435 payload_length = 8 + data_blocks * 4 * s->data_block_quadlets;
437 trace_out_packet(s, cycle, buffer, payload_length);
439 if (queue_out_packet(s, payload_length, false) < 0)
442 pcm = ACCESS_ONCE(s->pcm);
443 if (pcm && pcm_frames > 0)
444 update_pcm_pointers(s, pcm, pcm_frames);
446 /* No need to return the number of handled data blocks. */
450 static int handle_in_packet(struct amdtp_stream *s,
451 unsigned int payload_quadlets, __be32 *buffer,
452 unsigned int *data_blocks, unsigned int cycle,
456 unsigned int fmt, fdf;
457 unsigned int data_block_quadlets, data_block_counter, dbc_interval;
458 struct snd_pcm_substream *pcm;
459 unsigned int pcm_frames;
462 cip_header[0] = be32_to_cpu(buffer[0]);
463 cip_header[1] = be32_to_cpu(buffer[1]);
465 trace_in_packet(s, cycle, cip_header, payload_quadlets);
468 * This module supports 'Two-quadlet CIP header with SYT field'.
469 * For convenience, also check FMT field is AM824 or not.
471 if (((cip_header[0] & CIP_EOH_MASK) == CIP_EOH) ||
472 ((cip_header[1] & CIP_EOH_MASK) != CIP_EOH)) {
473 dev_info_ratelimited(&s->unit->device,
474 "Invalid CIP header for AMDTP: %08X:%08X\n",
475 cip_header[0], cip_header[1]);
481 /* Check valid protocol or not. */
482 fmt = (cip_header[1] & CIP_FMT_MASK) >> CIP_FMT_SHIFT;
484 dev_info_ratelimited(&s->unit->device,
485 "Detect unexpected protocol: %08x %08x\n",
486 cip_header[0], cip_header[1]);
492 /* Calculate data blocks */
493 fdf = (cip_header[1] & CIP_FDF_MASK) >> CIP_FDF_SHIFT;
494 if (payload_quadlets < 3 ||
495 (fmt == CIP_FMT_AM && fdf == AMDTP_FDF_NO_DATA)) {
498 data_block_quadlets =
499 (cip_header[0] & CIP_DBS_MASK) >> CIP_DBS_SHIFT;
500 /* avoid division by zero */
501 if (data_block_quadlets == 0) {
502 dev_err(&s->unit->device,
503 "Detect invalid value in dbs field: %08X\n",
507 if (s->flags & CIP_WRONG_DBS)
508 data_block_quadlets = s->data_block_quadlets;
510 *data_blocks = (payload_quadlets - 2) / data_block_quadlets;
513 /* Check data block counter continuity */
514 data_block_counter = cip_header[0] & CIP_DBC_MASK;
515 if (*data_blocks == 0 && (s->flags & CIP_EMPTY_HAS_WRONG_DBC) &&
516 s->data_block_counter != UINT_MAX)
517 data_block_counter = s->data_block_counter;
519 if (((s->flags & CIP_SKIP_DBC_ZERO_CHECK) &&
520 data_block_counter == s->tx_first_dbc) ||
521 s->data_block_counter == UINT_MAX) {
523 } else if (!(s->flags & CIP_DBC_IS_END_EVENT)) {
524 lost = data_block_counter != s->data_block_counter;
526 if ((*data_blocks > 0) && (s->tx_dbc_interval > 0))
527 dbc_interval = s->tx_dbc_interval;
529 dbc_interval = *data_blocks;
531 lost = data_block_counter !=
532 ((s->data_block_counter + dbc_interval) & 0xff);
536 dev_err(&s->unit->device,
537 "Detect discontinuity of CIP: %02X %02X\n",
538 s->data_block_counter, data_block_counter);
542 pcm_frames = s->process_data_blocks(s, buffer + 2, *data_blocks, &syt);
544 if (s->flags & CIP_DBC_IS_END_EVENT)
545 s->data_block_counter = data_block_counter;
547 s->data_block_counter =
548 (data_block_counter + *data_blocks) & 0xff;
550 if (queue_in_packet(s) < 0)
553 pcm = ACCESS_ONCE(s->pcm);
554 if (pcm && pcm_frames > 0)
555 update_pcm_pointers(s, pcm, pcm_frames);
561 * In CYCLE_TIMER register of IEEE 1394, 7 bits are used to represent second. On
562 * the other hand, in DMA descriptors of 1394 OHCI, 3 bits are used to represent
563 * it. Thus, via Linux firewire subsystem, we can get the 3 bits for second.
565 static inline u32 compute_cycle_count(u32 tstamp)
567 return (((tstamp >> 13) & 0x07) * 8000) + (tstamp & 0x1fff);
570 static inline u32 increment_cycle_count(u32 cycle, unsigned int addend)
573 if (cycle >= 8 * CYCLES_PER_SECOND)
574 cycle -= 8 * CYCLES_PER_SECOND;
578 static inline u32 decrement_cycle_count(u32 cycle, unsigned int subtrahend)
580 if (cycle < subtrahend)
581 cycle += 8 * CYCLES_PER_SECOND;
582 return cycle - subtrahend;
585 static void out_stream_callback(struct fw_iso_context *context, u32 tstamp,
586 size_t header_length, void *header,
589 struct amdtp_stream *s = private_data;
590 unsigned int i, syt, packets = header_length / 4;
591 unsigned int data_blocks;
594 if (s->packet_index < 0)
597 cycle = compute_cycle_count(tstamp);
599 /* Align to actual cycle count for the last packet. */
600 cycle = increment_cycle_count(cycle, QUEUE_LENGTH - packets);
602 for (i = 0; i < packets; ++i) {
603 cycle = increment_cycle_count(cycle, 1);
604 syt = calculate_syt(s, cycle);
605 data_blocks = calculate_data_blocks(s, syt);
607 if (handle_out_packet(s, data_blocks, cycle, syt) < 0) {
608 s->packet_index = -1;
609 amdtp_stream_pcm_abort(s);
614 fw_iso_context_queue_flush(s->context);
617 static void in_stream_callback(struct fw_iso_context *context, u32 tstamp,
618 size_t header_length, void *header,
621 struct amdtp_stream *s = private_data;
622 unsigned int p, syt, packets;
623 unsigned int payload_quadlets, max_payload_quadlets;
624 unsigned int data_blocks;
625 __be32 *buffer, *headers = header;
628 if (s->packet_index < 0)
631 /* The number of packets in buffer */
632 packets = header_length / IN_PACKET_HEADER_SIZE;
634 cycle = compute_cycle_count(tstamp);
636 /* Align to actual cycle count for the last packet. */
637 cycle = decrement_cycle_count(cycle, packets);
639 /* For buffer-over-run prevention. */
640 max_payload_quadlets = amdtp_stream_get_max_payload(s) / 4;
642 for (p = 0; p < packets; p++) {
643 cycle = increment_cycle_count(cycle, 1);
644 buffer = s->buffer.packets[s->packet_index].buffer;
646 /* The number of quadlets in this packet */
648 (be32_to_cpu(headers[p]) >> ISO_DATA_LENGTH_SHIFT) / 4;
649 if (payload_quadlets > max_payload_quadlets) {
650 dev_err(&s->unit->device,
651 "Detect jumbo payload: %02x %02x\n",
652 payload_quadlets, max_payload_quadlets);
653 s->packet_index = -1;
657 syt = be32_to_cpu(buffer[1]) & CIP_SYT_MASK;
658 if (handle_in_packet(s, payload_quadlets, buffer,
659 &data_blocks, cycle, syt) < 0) {
660 s->packet_index = -1;
664 /* Process sync slave stream */
665 if (s->sync_slave && s->sync_slave->callbacked) {
666 if (handle_out_packet(s->sync_slave,
667 data_blocks, cycle, syt) < 0) {
668 s->packet_index = -1;
674 /* Queueing error or detecting discontinuity */
675 if (s->packet_index < 0) {
676 amdtp_stream_pcm_abort(s);
678 /* Abort sync slave. */
680 s->sync_slave->packet_index = -1;
681 amdtp_stream_pcm_abort(s->sync_slave);
686 /* when sync to device, flush the packets for slave stream */
687 if (s->sync_slave && s->sync_slave->callbacked)
688 fw_iso_context_queue_flush(s->sync_slave->context);
690 fw_iso_context_queue_flush(s->context);
693 /* processing is done by master callback */
694 static void slave_stream_callback(struct fw_iso_context *context, u32 tstamp,
695 size_t header_length, void *header,
701 /* this is executed one time */
702 static void amdtp_stream_first_callback(struct fw_iso_context *context,
703 u32 tstamp, size_t header_length,
704 void *header, void *private_data)
706 struct amdtp_stream *s = private_data;
709 * For in-stream, first packet has come.
710 * For out-stream, prepared to transmit first packet
712 s->callbacked = true;
713 wake_up(&s->callback_wait);
715 if (s->direction == AMDTP_IN_STREAM)
716 context->callback.sc = in_stream_callback;
717 else if (s->flags & CIP_SYNC_TO_DEVICE)
718 context->callback.sc = slave_stream_callback;
720 context->callback.sc = out_stream_callback;
722 context->callback.sc(context, tstamp, header_length, header, s);
726 * amdtp_stream_start - start transferring packets
727 * @s: the AMDTP stream to start
728 * @channel: the isochronous channel on the bus
729 * @speed: firewire speed code
731 * The stream cannot be started until it has been configured with
732 * amdtp_stream_set_parameters() and it must be started before any PCM or MIDI
733 * device can be started.
735 int amdtp_stream_start(struct amdtp_stream *s, int channel, int speed)
737 static const struct {
738 unsigned int data_block;
739 unsigned int syt_offset;
740 } initial_state[] = {
741 [CIP_SFC_32000] = { 4, 3072 },
742 [CIP_SFC_48000] = { 6, 1024 },
743 [CIP_SFC_96000] = { 12, 1024 },
744 [CIP_SFC_192000] = { 24, 1024 },
745 [CIP_SFC_44100] = { 0, 67 },
746 [CIP_SFC_88200] = { 0, 67 },
747 [CIP_SFC_176400] = { 0, 67 },
749 unsigned int header_size;
750 enum dma_data_direction dir;
753 mutex_lock(&s->mutex);
755 if (WARN_ON(amdtp_stream_running(s) ||
756 (s->data_block_quadlets < 1))) {
761 if (s->direction == AMDTP_IN_STREAM &&
762 s->flags & CIP_SKIP_INIT_DBC_CHECK)
763 s->data_block_counter = UINT_MAX;
765 s->data_block_counter = 0;
766 s->data_block_state = initial_state[s->sfc].data_block;
767 s->syt_offset_state = initial_state[s->sfc].syt_offset;
768 s->last_syt_offset = TICKS_PER_CYCLE;
770 /* initialize packet buffer */
771 if (s->direction == AMDTP_IN_STREAM) {
772 dir = DMA_FROM_DEVICE;
773 type = FW_ISO_CONTEXT_RECEIVE;
774 header_size = IN_PACKET_HEADER_SIZE;
777 type = FW_ISO_CONTEXT_TRANSMIT;
778 header_size = OUT_PACKET_HEADER_SIZE;
780 err = iso_packets_buffer_init(&s->buffer, s->unit, QUEUE_LENGTH,
781 amdtp_stream_get_max_payload(s), dir);
785 s->context = fw_iso_context_create(fw_parent_device(s->unit)->card,
786 type, channel, speed, header_size,
787 amdtp_stream_first_callback, s);
788 if (IS_ERR(s->context)) {
789 err = PTR_ERR(s->context);
791 dev_err(&s->unit->device,
792 "no free stream on this controller\n");
796 amdtp_stream_update(s);
800 if (s->direction == AMDTP_IN_STREAM)
801 err = queue_in_packet(s);
803 err = queue_out_packet(s, 0, true);
806 } while (s->packet_index > 0);
808 /* NOTE: TAG1 matches CIP. This just affects in stream. */
809 tag = FW_ISO_CONTEXT_MATCH_TAG1;
810 if (s->flags & CIP_EMPTY_WITH_TAG0)
811 tag |= FW_ISO_CONTEXT_MATCH_TAG0;
813 s->callbacked = false;
814 err = fw_iso_context_start(s->context, -1, 0, tag);
818 mutex_unlock(&s->mutex);
823 fw_iso_context_destroy(s->context);
824 s->context = ERR_PTR(-1);
826 iso_packets_buffer_destroy(&s->buffer, s->unit);
828 mutex_unlock(&s->mutex);
832 EXPORT_SYMBOL(amdtp_stream_start);
835 * amdtp_stream_pcm_pointer - get the PCM buffer position
836 * @s: the AMDTP stream that transports the PCM data
838 * Returns the current buffer position, in frames.
840 unsigned long amdtp_stream_pcm_pointer(struct amdtp_stream *s)
842 /* this optimization is allowed to be racy */
843 if (s->pointer_flush && amdtp_stream_running(s))
844 fw_iso_context_flush_completions(s->context);
846 s->pointer_flush = true;
848 return ACCESS_ONCE(s->pcm_buffer_pointer);
850 EXPORT_SYMBOL(amdtp_stream_pcm_pointer);
853 * amdtp_stream_update - update the stream after a bus reset
854 * @s: the AMDTP stream
856 void amdtp_stream_update(struct amdtp_stream *s)
859 ACCESS_ONCE(s->source_node_id_field) =
860 (fw_parent_device(s->unit)->card->node_id << CIP_SID_SHIFT) &
863 EXPORT_SYMBOL(amdtp_stream_update);
866 * amdtp_stream_stop - stop sending packets
867 * @s: the AMDTP stream to stop
869 * All PCM and MIDI devices of the stream must be stopped before the stream
870 * itself can be stopped.
872 void amdtp_stream_stop(struct amdtp_stream *s)
874 mutex_lock(&s->mutex);
876 if (!amdtp_stream_running(s)) {
877 mutex_unlock(&s->mutex);
881 tasklet_kill(&s->period_tasklet);
882 fw_iso_context_stop(s->context);
883 fw_iso_context_destroy(s->context);
884 s->context = ERR_PTR(-1);
885 iso_packets_buffer_destroy(&s->buffer, s->unit);
887 s->callbacked = false;
889 mutex_unlock(&s->mutex);
891 EXPORT_SYMBOL(amdtp_stream_stop);
894 * amdtp_stream_pcm_abort - abort the running PCM device
895 * @s: the AMDTP stream about to be stopped
897 * If the isochronous stream needs to be stopped asynchronously, call this
898 * function first to stop the PCM device.
900 void amdtp_stream_pcm_abort(struct amdtp_stream *s)
902 struct snd_pcm_substream *pcm;
904 pcm = ACCESS_ONCE(s->pcm);
906 snd_pcm_stop_xrun(pcm);
908 EXPORT_SYMBOL(amdtp_stream_pcm_abort);