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
30 #define TAG_NO_CIP_HEADER 0
33 /* common isochronous packet header parameters */
34 #define CIP_EOH_SHIFT 31
35 #define CIP_EOH (1u << CIP_EOH_SHIFT)
36 #define CIP_EOH_MASK 0x80000000
37 #define CIP_SID_SHIFT 24
38 #define CIP_SID_MASK 0x3f000000
39 #define CIP_DBS_MASK 0x00ff0000
40 #define CIP_DBS_SHIFT 16
41 #define CIP_SPH_MASK 0x00000400
42 #define CIP_SPH_SHIFT 10
43 #define CIP_DBC_MASK 0x000000ff
44 #define CIP_FMT_SHIFT 24
45 #define CIP_FMT_MASK 0x3f000000
46 #define CIP_FDF_MASK 0x00ff0000
47 #define CIP_FDF_SHIFT 16
48 #define CIP_SYT_MASK 0x0000ffff
49 #define CIP_SYT_NO_INFO 0xffff
51 /* Audio and Music transfer protocol specific parameters */
52 #define CIP_FMT_AM 0x10
53 #define AMDTP_FDF_NO_DATA 0xff
55 /* TODO: make these configurable */
56 #define INTERRUPT_INTERVAL 16
57 #define QUEUE_LENGTH 48
59 #define IN_PACKET_HEADER_SIZE 4
60 #define OUT_PACKET_HEADER_SIZE 0
62 static void pcm_period_tasklet(unsigned long data);
65 * amdtp_stream_init - initialize an AMDTP stream structure
66 * @s: the AMDTP stream to initialize
67 * @unit: the target of the stream
68 * @dir: the direction of stream
69 * @flags: the packet transmission method to use
70 * @fmt: the value of fmt field in CIP header
71 * @process_data_blocks: callback handler to process data blocks
72 * @protocol_size: the size to allocate newly for protocol
74 int amdtp_stream_init(struct amdtp_stream *s, struct fw_unit *unit,
75 enum amdtp_stream_direction dir, enum cip_flags flags,
77 amdtp_stream_process_data_blocks_t process_data_blocks,
78 unsigned int protocol_size)
80 if (process_data_blocks == NULL)
83 s->protocol = kzalloc(protocol_size, GFP_KERNEL);
90 s->context = ERR_PTR(-1);
91 mutex_init(&s->mutex);
92 tasklet_init(&s->period_tasklet, pcm_period_tasklet, (unsigned long)s);
95 init_waitqueue_head(&s->callback_wait);
96 s->callbacked = false;
99 s->process_data_blocks = process_data_blocks;
103 EXPORT_SYMBOL(amdtp_stream_init);
106 * amdtp_stream_destroy - free stream resources
107 * @s: the AMDTP stream to destroy
109 void amdtp_stream_destroy(struct amdtp_stream *s)
111 /* Not initialized. */
112 if (s->protocol == NULL)
115 WARN_ON(amdtp_stream_running(s));
117 mutex_destroy(&s->mutex);
119 EXPORT_SYMBOL(amdtp_stream_destroy);
121 const unsigned int amdtp_syt_intervals[CIP_SFC_COUNT] = {
125 [CIP_SFC_88200] = 16,
126 [CIP_SFC_96000] = 16,
127 [CIP_SFC_176400] = 32,
128 [CIP_SFC_192000] = 32,
130 EXPORT_SYMBOL(amdtp_syt_intervals);
132 const unsigned int amdtp_rate_table[CIP_SFC_COUNT] = {
133 [CIP_SFC_32000] = 32000,
134 [CIP_SFC_44100] = 44100,
135 [CIP_SFC_48000] = 48000,
136 [CIP_SFC_88200] = 88200,
137 [CIP_SFC_96000] = 96000,
138 [CIP_SFC_176400] = 176400,
139 [CIP_SFC_192000] = 192000,
141 EXPORT_SYMBOL(amdtp_rate_table);
143 static int apply_constraint_to_size(struct snd_pcm_hw_params *params,
144 struct snd_pcm_hw_rule *rule)
146 struct snd_interval *s = hw_param_interval(params, rule->var);
147 const struct snd_interval *r =
148 hw_param_interval_c(params, SNDRV_PCM_HW_PARAM_RATE);
149 struct snd_interval t = {0};
150 unsigned int step = 0;
153 for (i = 0; i < CIP_SFC_COUNT; ++i) {
154 if (snd_interval_test(r, amdtp_rate_table[i]))
155 step = max(step, amdtp_syt_intervals[i]);
158 t.min = roundup(s->min, step);
159 t.max = rounddown(s->max, step);
162 return snd_interval_refine(s, &t);
166 * amdtp_stream_add_pcm_hw_constraints - add hw constraints for PCM substream
167 * @s: the AMDTP stream, which must be initialized.
168 * @runtime: the PCM substream runtime
170 int amdtp_stream_add_pcm_hw_constraints(struct amdtp_stream *s,
171 struct snd_pcm_runtime *runtime)
173 struct snd_pcm_hardware *hw = &runtime->hw;
176 hw->info = SNDRV_PCM_INFO_BATCH |
177 SNDRV_PCM_INFO_BLOCK_TRANSFER |
178 SNDRV_PCM_INFO_INTERLEAVED |
179 SNDRV_PCM_INFO_JOINT_DUPLEX |
180 SNDRV_PCM_INFO_MMAP |
181 SNDRV_PCM_INFO_MMAP_VALID;
183 /* SNDRV_PCM_INFO_BATCH */
185 hw->periods_max = UINT_MAX;
187 /* bytes for a frame */
188 hw->period_bytes_min = 4 * hw->channels_max;
190 /* Just to prevent from allocating much pages. */
191 hw->period_bytes_max = hw->period_bytes_min * 2048;
192 hw->buffer_bytes_max = hw->period_bytes_max * hw->periods_min;
195 * Currently firewire-lib processes 16 packets in one software
196 * interrupt callback. This equals to 2msec but actually the
197 * interval of the interrupts has a jitter.
198 * Additionally, even if adding a constraint to fit period size to
199 * 2msec, actual calculated frames per period doesn't equal to 2msec,
200 * depending on sampling rate.
201 * Anyway, the interval to call snd_pcm_period_elapsed() cannot 2msec.
202 * Here let us use 5msec for safe period interrupt.
204 err = snd_pcm_hw_constraint_minmax(runtime,
205 SNDRV_PCM_HW_PARAM_PERIOD_TIME,
210 /* Non-Blocking stream has no more constraints */
211 if (!(s->flags & CIP_BLOCKING))
215 * One AMDTP packet can include some frames. In blocking mode, the
216 * number equals to SYT_INTERVAL. So the number is 8, 16 or 32,
217 * depending on its sampling rate. For accurate period interrupt, it's
218 * preferrable to align period/buffer sizes to current SYT_INTERVAL.
220 err = snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_PERIOD_SIZE,
221 apply_constraint_to_size, NULL,
222 SNDRV_PCM_HW_PARAM_PERIOD_SIZE,
223 SNDRV_PCM_HW_PARAM_RATE, -1);
226 err = snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_BUFFER_SIZE,
227 apply_constraint_to_size, NULL,
228 SNDRV_PCM_HW_PARAM_BUFFER_SIZE,
229 SNDRV_PCM_HW_PARAM_RATE, -1);
235 EXPORT_SYMBOL(amdtp_stream_add_pcm_hw_constraints);
238 * amdtp_stream_set_parameters - set stream parameters
239 * @s: the AMDTP stream to configure
240 * @rate: the sample rate
241 * @data_block_quadlets: the size of a data block in quadlet unit
243 * The parameters must be set before the stream is started, and must not be
244 * changed while the stream is running.
246 int amdtp_stream_set_parameters(struct amdtp_stream *s, unsigned int rate,
247 unsigned int data_block_quadlets)
251 for (sfc = 0; sfc < ARRAY_SIZE(amdtp_rate_table); ++sfc) {
252 if (amdtp_rate_table[sfc] == rate)
255 if (sfc == ARRAY_SIZE(amdtp_rate_table))
259 s->data_block_quadlets = data_block_quadlets;
260 s->syt_interval = amdtp_syt_intervals[sfc];
262 /* default buffering in the device */
263 s->transfer_delay = TRANSFER_DELAY_TICKS - TICKS_PER_CYCLE;
264 if (s->flags & CIP_BLOCKING)
265 /* additional buffering needed to adjust for no-data packets */
266 s->transfer_delay += TICKS_PER_SECOND * s->syt_interval / rate;
270 EXPORT_SYMBOL(amdtp_stream_set_parameters);
273 * amdtp_stream_get_max_payload - get the stream's packet size
274 * @s: the AMDTP stream
276 * This function must not be called before the stream has been configured
277 * with amdtp_stream_set_parameters().
279 unsigned int amdtp_stream_get_max_payload(struct amdtp_stream *s)
281 unsigned int multiplier = 1;
282 unsigned int header_size = 0;
284 if (s->flags & CIP_JUMBO_PAYLOAD)
286 if (!(s->flags & CIP_NO_HEADER))
290 s->syt_interval * s->data_block_quadlets * 4 * multiplier;
292 EXPORT_SYMBOL(amdtp_stream_get_max_payload);
295 * amdtp_stream_pcm_prepare - prepare PCM device for running
296 * @s: the AMDTP stream
298 * This function should be called from the PCM device's .prepare callback.
300 void amdtp_stream_pcm_prepare(struct amdtp_stream *s)
302 tasklet_kill(&s->period_tasklet);
303 s->pcm_buffer_pointer = 0;
304 s->pcm_period_pointer = 0;
306 EXPORT_SYMBOL(amdtp_stream_pcm_prepare);
308 static unsigned int calculate_data_blocks(struct amdtp_stream *s,
311 unsigned int phase, data_blocks;
314 if (s->flags & CIP_BLOCKING) {
315 /* This module generate empty packet for 'no data'. */
316 if (syt == CIP_SYT_NO_INFO)
319 data_blocks = s->syt_interval;
320 /* Non-blocking mode. */
322 if (!cip_sfc_is_base_44100(s->sfc)) {
323 /* Sample_rate / 8000 is an integer, and precomputed. */
324 data_blocks = s->data_block_state;
326 phase = s->data_block_state;
329 * This calculates the number of data blocks per packet so that
330 * 1) the overall rate is correct and exactly synchronized to
332 * 2) packets with a rounded-up number of blocks occur as early
333 * as possible in the sequence (to prevent underruns of the
336 if (s->sfc == CIP_SFC_44100)
337 /* 6 6 5 6 5 6 5 ... */
338 data_blocks = 5 + ((phase & 1) ^
339 (phase == 0 || phase >= 40));
341 /* 12 11 11 11 11 ... or 23 22 22 22 22 ... */
342 data_blocks = 11 * (s->sfc >> 1) + (phase == 0);
343 if (++phase >= (80 >> (s->sfc >> 1)))
345 s->data_block_state = phase;
352 static unsigned int calculate_syt(struct amdtp_stream *s,
355 unsigned int syt_offset, phase, index, syt;
357 if (s->last_syt_offset < TICKS_PER_CYCLE) {
358 if (!cip_sfc_is_base_44100(s->sfc))
359 syt_offset = s->last_syt_offset + s->syt_offset_state;
362 * The time, in ticks, of the n'th SYT_INTERVAL sample is:
363 * n * SYT_INTERVAL * 24576000 / sample_rate
364 * Modulo TICKS_PER_CYCLE, the difference between successive
365 * elements is about 1386.23. Rounding the results of this
366 * formula to the SYT precision results in a sequence of
367 * differences that begins with:
368 * 1386 1386 1387 1386 1386 1386 1387 1386 1386 1386 1387 ...
369 * This code generates _exactly_ the same sequence.
371 phase = s->syt_offset_state;
373 syt_offset = s->last_syt_offset;
374 syt_offset += 1386 + ((index && !(index & 3)) ||
378 s->syt_offset_state = phase;
381 syt_offset = s->last_syt_offset - TICKS_PER_CYCLE;
382 s->last_syt_offset = syt_offset;
384 if (syt_offset < TICKS_PER_CYCLE) {
385 syt_offset += s->transfer_delay;
386 syt = (cycle + syt_offset / TICKS_PER_CYCLE) << 12;
387 syt += syt_offset % TICKS_PER_CYCLE;
389 return syt & CIP_SYT_MASK;
391 return CIP_SYT_NO_INFO;
395 static void update_pcm_pointers(struct amdtp_stream *s,
396 struct snd_pcm_substream *pcm,
401 ptr = s->pcm_buffer_pointer + frames;
402 if (ptr >= pcm->runtime->buffer_size)
403 ptr -= pcm->runtime->buffer_size;
404 WRITE_ONCE(s->pcm_buffer_pointer, ptr);
406 s->pcm_period_pointer += frames;
407 if (s->pcm_period_pointer >= pcm->runtime->period_size) {
408 s->pcm_period_pointer -= pcm->runtime->period_size;
409 tasklet_hi_schedule(&s->period_tasklet);
413 static void pcm_period_tasklet(unsigned long data)
415 struct amdtp_stream *s = (void *)data;
416 struct snd_pcm_substream *pcm = READ_ONCE(s->pcm);
419 snd_pcm_period_elapsed(pcm);
422 static int queue_packet(struct amdtp_stream *s, unsigned int header_length,
423 unsigned int payload_length)
425 struct fw_iso_packet p = {0};
428 if (IS_ERR(s->context))
431 p.interrupt = IS_ALIGNED(s->packet_index + 1, INTERRUPT_INTERVAL);
433 p.header_length = header_length;
434 if (payload_length > 0)
435 p.payload_length = payload_length;
438 err = fw_iso_context_queue(s->context, &p, &s->buffer.iso_buffer,
439 s->buffer.packets[s->packet_index].offset);
441 dev_err(&s->unit->device, "queueing error: %d\n", err);
445 if (++s->packet_index >= QUEUE_LENGTH)
451 static inline int queue_out_packet(struct amdtp_stream *s,
452 unsigned int payload_length)
454 return queue_packet(s, OUT_PACKET_HEADER_SIZE, payload_length);
457 static inline int queue_in_packet(struct amdtp_stream *s)
459 return queue_packet(s, IN_PACKET_HEADER_SIZE, s->max_payload_length);
462 static int handle_out_packet(struct amdtp_stream *s,
463 unsigned int payload_length, unsigned int cycle,
468 unsigned int data_blocks;
469 unsigned int pcm_frames;
470 struct snd_pcm_substream *pcm;
472 buffer = s->buffer.packets[s->packet_index].buffer;
473 syt = calculate_syt(s, cycle);
474 data_blocks = calculate_data_blocks(s, syt);
475 pcm_frames = s->process_data_blocks(s, buffer + 2, data_blocks, &syt);
477 if (s->flags & CIP_DBC_IS_END_EVENT)
478 s->data_block_counter =
479 (s->data_block_counter + data_blocks) & 0xff;
481 buffer[0] = cpu_to_be32(READ_ONCE(s->source_node_id_field) |
482 (s->data_block_quadlets << CIP_DBS_SHIFT) |
483 ((s->sph << CIP_SPH_SHIFT) & CIP_SPH_MASK) |
484 s->data_block_counter);
485 buffer[1] = cpu_to_be32(CIP_EOH |
486 ((s->fmt << CIP_FMT_SHIFT) & CIP_FMT_MASK) |
487 ((s->fdf << CIP_FDF_SHIFT) & CIP_FDF_MASK) |
488 (syt & CIP_SYT_MASK));
490 if (!(s->flags & CIP_DBC_IS_END_EVENT))
491 s->data_block_counter =
492 (s->data_block_counter + data_blocks) & 0xff;
493 payload_length = 8 + data_blocks * 4 * s->data_block_quadlets;
495 trace_out_packet(s, cycle, buffer, payload_length, index);
497 if (queue_out_packet(s, payload_length) < 0)
500 pcm = READ_ONCE(s->pcm);
501 if (pcm && pcm_frames > 0)
502 update_pcm_pointers(s, pcm, pcm_frames);
504 /* No need to return the number of handled data blocks. */
508 static int handle_out_packet_without_header(struct amdtp_stream *s,
509 unsigned int payload_length, unsigned int cycle,
514 unsigned int data_blocks;
515 unsigned int pcm_frames;
516 struct snd_pcm_substream *pcm;
518 buffer = s->buffer.packets[s->packet_index].buffer;
519 syt = calculate_syt(s, cycle);
520 data_blocks = calculate_data_blocks(s, syt);
521 pcm_frames = s->process_data_blocks(s, buffer, data_blocks, &syt);
522 s->data_block_counter = (s->data_block_counter + data_blocks) & 0xff;
524 payload_length = data_blocks * 4 * s->data_block_quadlets;
526 trace_out_packet_without_header(s, cycle, payload_length, data_blocks,
529 if (queue_out_packet(s, payload_length) < 0)
532 pcm = READ_ONCE(s->pcm);
533 if (pcm && pcm_frames > 0)
534 update_pcm_pointers(s, pcm, pcm_frames);
536 /* No need to return the number of handled data blocks. */
540 static int handle_in_packet(struct amdtp_stream *s,
541 unsigned int payload_length, unsigned int cycle,
546 unsigned int sph, fmt, fdf, syt;
547 unsigned int data_block_quadlets, data_block_counter, dbc_interval;
548 unsigned int data_blocks;
549 struct snd_pcm_substream *pcm;
550 unsigned int pcm_frames;
553 buffer = s->buffer.packets[s->packet_index].buffer;
554 cip_header[0] = be32_to_cpu(buffer[0]);
555 cip_header[1] = be32_to_cpu(buffer[1]);
557 trace_in_packet(s, cycle, cip_header, payload_length, index);
560 * This module supports 'Two-quadlet CIP header with SYT field'.
561 * For convenience, also check FMT field is AM824 or not.
563 if ((((cip_header[0] & CIP_EOH_MASK) == CIP_EOH) ||
564 ((cip_header[1] & CIP_EOH_MASK) != CIP_EOH)) &&
565 (!(s->flags & CIP_HEADER_WITHOUT_EOH))) {
566 dev_info_ratelimited(&s->unit->device,
567 "Invalid CIP header for AMDTP: %08X:%08X\n",
568 cip_header[0], cip_header[1]);
574 /* Check valid protocol or not. */
575 sph = (cip_header[0] & CIP_SPH_MASK) >> CIP_SPH_SHIFT;
576 fmt = (cip_header[1] & CIP_FMT_MASK) >> CIP_FMT_SHIFT;
577 if (sph != s->sph || fmt != s->fmt) {
578 dev_info_ratelimited(&s->unit->device,
579 "Detect unexpected protocol: %08x %08x\n",
580 cip_header[0], cip_header[1]);
586 /* Calculate data blocks */
587 fdf = (cip_header[1] & CIP_FDF_MASK) >> CIP_FDF_SHIFT;
588 if (payload_length < 12 ||
589 (fmt == CIP_FMT_AM && fdf == AMDTP_FDF_NO_DATA)) {
592 data_block_quadlets =
593 (cip_header[0] & CIP_DBS_MASK) >> CIP_DBS_SHIFT;
594 /* avoid division by zero */
595 if (data_block_quadlets == 0) {
596 dev_err(&s->unit->device,
597 "Detect invalid value in dbs field: %08X\n",
601 if (s->flags & CIP_WRONG_DBS)
602 data_block_quadlets = s->data_block_quadlets;
604 data_blocks = (payload_length / 4 - 2) /
608 /* Check data block counter continuity */
609 data_block_counter = cip_header[0] & CIP_DBC_MASK;
610 if (data_blocks == 0 && (s->flags & CIP_EMPTY_HAS_WRONG_DBC) &&
611 s->data_block_counter != UINT_MAX)
612 data_block_counter = s->data_block_counter;
614 if (((s->flags & CIP_SKIP_DBC_ZERO_CHECK) &&
615 data_block_counter == s->tx_first_dbc) ||
616 s->data_block_counter == UINT_MAX) {
618 } else if (!(s->flags & CIP_DBC_IS_END_EVENT)) {
619 lost = data_block_counter != s->data_block_counter;
621 if (data_blocks > 0 && s->tx_dbc_interval > 0)
622 dbc_interval = s->tx_dbc_interval;
624 dbc_interval = data_blocks;
626 lost = data_block_counter !=
627 ((s->data_block_counter + dbc_interval) & 0xff);
631 dev_err(&s->unit->device,
632 "Detect discontinuity of CIP: %02X %02X\n",
633 s->data_block_counter, data_block_counter);
637 syt = be32_to_cpu(buffer[1]) & CIP_SYT_MASK;
638 pcm_frames = s->process_data_blocks(s, buffer + 2, data_blocks, &syt);
640 if (s->flags & CIP_DBC_IS_END_EVENT)
641 s->data_block_counter = data_block_counter;
643 s->data_block_counter =
644 (data_block_counter + data_blocks) & 0xff;
646 if (queue_in_packet(s) < 0)
649 pcm = READ_ONCE(s->pcm);
650 if (pcm && pcm_frames > 0)
651 update_pcm_pointers(s, pcm, pcm_frames);
656 static int handle_in_packet_without_header(struct amdtp_stream *s,
657 unsigned int payload_quadlets, unsigned int cycle,
661 unsigned int data_blocks;
662 struct snd_pcm_substream *pcm;
663 unsigned int pcm_frames;
665 buffer = s->buffer.packets[s->packet_index].buffer;
666 data_blocks = payload_quadlets / s->data_block_quadlets;
668 trace_in_packet_without_header(s, cycle, payload_quadlets, data_blocks,
671 pcm_frames = s->process_data_blocks(s, buffer, data_blocks, NULL);
672 s->data_block_counter = (s->data_block_counter + data_blocks) & 0xff;
674 if (queue_in_packet(s) < 0)
677 pcm = READ_ONCE(s->pcm);
678 if (pcm && pcm_frames > 0)
679 update_pcm_pointers(s, pcm, pcm_frames);
685 * In CYCLE_TIMER register of IEEE 1394, 7 bits are used to represent second. On
686 * the other hand, in DMA descriptors of 1394 OHCI, 3 bits are used to represent
687 * it. Thus, via Linux firewire subsystem, we can get the 3 bits for second.
689 static inline u32 compute_cycle_count(u32 tstamp)
691 return (((tstamp >> 13) & 0x07) * 8000) + (tstamp & 0x1fff);
694 static inline u32 increment_cycle_count(u32 cycle, unsigned int addend)
697 if (cycle >= 8 * CYCLES_PER_SECOND)
698 cycle -= 8 * CYCLES_PER_SECOND;
702 static inline u32 decrement_cycle_count(u32 cycle, unsigned int subtrahend)
704 if (cycle < subtrahend)
705 cycle += 8 * CYCLES_PER_SECOND;
706 return cycle - subtrahend;
709 static void out_stream_callback(struct fw_iso_context *context, u32 tstamp,
710 size_t header_length, void *header,
713 struct amdtp_stream *s = private_data;
714 unsigned int i, packets = header_length / 4;
717 if (s->packet_index < 0)
720 cycle = compute_cycle_count(tstamp);
722 /* Align to actual cycle count for the last packet. */
723 cycle = increment_cycle_count(cycle, QUEUE_LENGTH - packets);
725 for (i = 0; i < packets; ++i) {
726 cycle = increment_cycle_count(cycle, 1);
727 if (s->handle_packet(s, 0, cycle, i) < 0) {
728 s->packet_index = -1;
730 amdtp_stream_pcm_abort(s);
731 WRITE_ONCE(s->pcm_buffer_pointer, SNDRV_PCM_POS_XRUN);
736 fw_iso_context_queue_flush(s->context);
739 static void in_stream_callback(struct fw_iso_context *context, u32 tstamp,
740 size_t header_length, void *header,
743 struct amdtp_stream *s = private_data;
744 unsigned int i, packets;
745 unsigned int payload_length, max_payload_length;
746 __be32 *headers = header;
749 if (s->packet_index < 0)
752 /* The number of packets in buffer */
753 packets = header_length / IN_PACKET_HEADER_SIZE;
755 cycle = compute_cycle_count(tstamp);
757 /* Align to actual cycle count for the last packet. */
758 cycle = decrement_cycle_count(cycle, packets);
760 /* For buffer-over-run prevention. */
761 max_payload_length = s->max_payload_length;
763 for (i = 0; i < packets; i++) {
764 cycle = increment_cycle_count(cycle, 1);
766 /* The number of bytes in this packet */
768 (be32_to_cpu(headers[i]) >> ISO_DATA_LENGTH_SHIFT);
769 if (payload_length > max_payload_length) {
770 dev_err(&s->unit->device,
771 "Detect jumbo payload: %04x %04x\n",
772 payload_length, max_payload_length);
776 if (s->handle_packet(s, payload_length, cycle, i) < 0)
780 /* Queueing error or detecting invalid payload. */
782 s->packet_index = -1;
784 amdtp_stream_pcm_abort(s);
785 WRITE_ONCE(s->pcm_buffer_pointer, SNDRV_PCM_POS_XRUN);
789 fw_iso_context_queue_flush(s->context);
792 /* this is executed one time */
793 static void amdtp_stream_first_callback(struct fw_iso_context *context,
794 u32 tstamp, size_t header_length,
795 void *header, void *private_data)
797 struct amdtp_stream *s = private_data;
799 unsigned int packets;
802 * For in-stream, first packet has come.
803 * For out-stream, prepared to transmit first packet
805 s->callbacked = true;
806 wake_up(&s->callback_wait);
808 cycle = compute_cycle_count(tstamp);
810 if (s->direction == AMDTP_IN_STREAM) {
811 packets = header_length / IN_PACKET_HEADER_SIZE;
812 cycle = decrement_cycle_count(cycle, packets);
813 context->callback.sc = in_stream_callback;
814 if (s->flags & CIP_NO_HEADER)
815 s->handle_packet = handle_in_packet_without_header;
817 s->handle_packet = handle_in_packet;
819 packets = header_length / 4;
820 cycle = increment_cycle_count(cycle, QUEUE_LENGTH - packets);
821 context->callback.sc = out_stream_callback;
822 if (s->flags & CIP_NO_HEADER)
823 s->handle_packet = handle_out_packet_without_header;
825 s->handle_packet = handle_out_packet;
828 s->start_cycle = cycle;
830 context->callback.sc(context, tstamp, header_length, header, s);
834 * amdtp_stream_start - start transferring packets
835 * @s: the AMDTP stream to start
836 * @channel: the isochronous channel on the bus
837 * @speed: firewire speed code
839 * The stream cannot be started until it has been configured with
840 * amdtp_stream_set_parameters() and it must be started before any PCM or MIDI
841 * device can be started.
843 int amdtp_stream_start(struct amdtp_stream *s, int channel, int speed)
845 static const struct {
846 unsigned int data_block;
847 unsigned int syt_offset;
848 } initial_state[] = {
849 [CIP_SFC_32000] = { 4, 3072 },
850 [CIP_SFC_48000] = { 6, 1024 },
851 [CIP_SFC_96000] = { 12, 1024 },
852 [CIP_SFC_192000] = { 24, 1024 },
853 [CIP_SFC_44100] = { 0, 67 },
854 [CIP_SFC_88200] = { 0, 67 },
855 [CIP_SFC_176400] = { 0, 67 },
857 unsigned int header_size;
858 enum dma_data_direction dir;
861 mutex_lock(&s->mutex);
863 if (WARN_ON(amdtp_stream_running(s) ||
864 (s->data_block_quadlets < 1))) {
869 if (s->direction == AMDTP_IN_STREAM)
870 s->data_block_counter = UINT_MAX;
872 s->data_block_counter = 0;
873 s->data_block_state = initial_state[s->sfc].data_block;
874 s->syt_offset_state = initial_state[s->sfc].syt_offset;
875 s->last_syt_offset = TICKS_PER_CYCLE;
877 /* initialize packet buffer */
878 if (s->direction == AMDTP_IN_STREAM) {
879 dir = DMA_FROM_DEVICE;
880 type = FW_ISO_CONTEXT_RECEIVE;
881 header_size = IN_PACKET_HEADER_SIZE;
884 type = FW_ISO_CONTEXT_TRANSMIT;
885 header_size = OUT_PACKET_HEADER_SIZE;
887 err = iso_packets_buffer_init(&s->buffer, s->unit, QUEUE_LENGTH,
888 amdtp_stream_get_max_payload(s), dir);
892 s->context = fw_iso_context_create(fw_parent_device(s->unit)->card,
893 type, channel, speed, header_size,
894 amdtp_stream_first_callback, s);
895 if (IS_ERR(s->context)) {
896 err = PTR_ERR(s->context);
898 dev_err(&s->unit->device,
899 "no free stream on this controller\n");
903 amdtp_stream_update(s);
905 if (s->direction == AMDTP_IN_STREAM)
906 s->max_payload_length = amdtp_stream_get_max_payload(s);
908 if (s->flags & CIP_NO_HEADER)
909 s->tag = TAG_NO_CIP_HEADER;
915 if (s->direction == AMDTP_IN_STREAM)
916 err = queue_in_packet(s);
918 err = queue_out_packet(s, 0);
921 } while (s->packet_index > 0);
923 /* NOTE: TAG1 matches CIP. This just affects in stream. */
924 tag = FW_ISO_CONTEXT_MATCH_TAG1;
925 if ((s->flags & CIP_EMPTY_WITH_TAG0) || (s->flags & CIP_NO_HEADER))
926 tag |= FW_ISO_CONTEXT_MATCH_TAG0;
928 s->callbacked = false;
929 err = fw_iso_context_start(s->context, -1, 0, tag);
933 mutex_unlock(&s->mutex);
938 fw_iso_context_destroy(s->context);
939 s->context = ERR_PTR(-1);
941 iso_packets_buffer_destroy(&s->buffer, s->unit);
943 mutex_unlock(&s->mutex);
947 EXPORT_SYMBOL(amdtp_stream_start);
950 * amdtp_stream_pcm_pointer - get the PCM buffer position
951 * @s: the AMDTP stream that transports the PCM data
953 * Returns the current buffer position, in frames.
955 unsigned long amdtp_stream_pcm_pointer(struct amdtp_stream *s)
958 * This function is called in software IRQ context of period_tasklet or
961 * When the software IRQ context was scheduled by software IRQ context
962 * of IR/IT contexts, queued packets were already handled. Therefore,
963 * no need to flush the queue in buffer anymore.
965 * When the process context reach here, some packets will be already
966 * queued in the buffer. These packets should be handled immediately
967 * to keep better granularity of PCM pointer.
969 * Later, the process context will sometimes schedules software IRQ
970 * context of the period_tasklet. Then, no need to flush the queue by
971 * the same reason as described for IR/IT contexts.
973 if (!in_interrupt() && amdtp_stream_running(s))
974 fw_iso_context_flush_completions(s->context);
976 return READ_ONCE(s->pcm_buffer_pointer);
978 EXPORT_SYMBOL(amdtp_stream_pcm_pointer);
981 * amdtp_stream_pcm_ack - acknowledge queued PCM frames
982 * @s: the AMDTP stream that transfers the PCM frames
984 * Returns zero always.
986 int amdtp_stream_pcm_ack(struct amdtp_stream *s)
989 * Process isochronous packets for recent isochronous cycle to handle
992 if (amdtp_stream_running(s))
993 fw_iso_context_flush_completions(s->context);
997 EXPORT_SYMBOL(amdtp_stream_pcm_ack);
1000 * amdtp_stream_update - update the stream after a bus reset
1001 * @s: the AMDTP stream
1003 void amdtp_stream_update(struct amdtp_stream *s)
1006 WRITE_ONCE(s->source_node_id_field,
1007 (fw_parent_device(s->unit)->card->node_id << CIP_SID_SHIFT) & CIP_SID_MASK);
1009 EXPORT_SYMBOL(amdtp_stream_update);
1012 * amdtp_stream_stop - stop sending packets
1013 * @s: the AMDTP stream to stop
1015 * All PCM and MIDI devices of the stream must be stopped before the stream
1016 * itself can be stopped.
1018 void amdtp_stream_stop(struct amdtp_stream *s)
1020 mutex_lock(&s->mutex);
1022 if (!amdtp_stream_running(s)) {
1023 mutex_unlock(&s->mutex);
1027 tasklet_kill(&s->period_tasklet);
1028 fw_iso_context_stop(s->context);
1029 fw_iso_context_destroy(s->context);
1030 s->context = ERR_PTR(-1);
1031 iso_packets_buffer_destroy(&s->buffer, s->unit);
1033 s->callbacked = false;
1035 mutex_unlock(&s->mutex);
1037 EXPORT_SYMBOL(amdtp_stream_stop);
1040 * amdtp_stream_pcm_abort - abort the running PCM device
1041 * @s: the AMDTP stream about to be stopped
1043 * If the isochronous stream needs to be stopped asynchronously, call this
1044 * function first to stop the PCM device.
1046 void amdtp_stream_pcm_abort(struct amdtp_stream *s)
1048 struct snd_pcm_substream *pcm;
1050 pcm = READ_ONCE(s->pcm);
1052 snd_pcm_stop_xrun(pcm);
1054 EXPORT_SYMBOL(amdtp_stream_pcm_abort);