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 // For iso header, tstamp and 2 CIP header.
60 #define IR_CTX_HEADER_SIZE_CIP 16
61 // For iso header and tstamp.
62 #define IR_CTX_HEADER_SIZE_NO_CIP 8
63 #define HEADER_TSTAMP_MASK 0x0000ffff
65 static void pcm_period_tasklet(unsigned long data);
68 * amdtp_stream_init - initialize an AMDTP stream structure
69 * @s: the AMDTP stream to initialize
70 * @unit: the target of the stream
71 * @dir: the direction of stream
72 * @flags: the packet transmission method to use
73 * @fmt: the value of fmt field in CIP header
74 * @process_data_blocks: callback handler to process data blocks
75 * @protocol_size: the size to allocate newly for protocol
77 int amdtp_stream_init(struct amdtp_stream *s, struct fw_unit *unit,
78 enum amdtp_stream_direction dir, enum cip_flags flags,
80 amdtp_stream_process_data_blocks_t process_data_blocks,
81 unsigned int protocol_size)
83 if (process_data_blocks == NULL)
86 s->protocol = kzalloc(protocol_size, GFP_KERNEL);
93 s->context = ERR_PTR(-1);
94 mutex_init(&s->mutex);
95 tasklet_init(&s->period_tasklet, pcm_period_tasklet, (unsigned long)s);
98 init_waitqueue_head(&s->callback_wait);
99 s->callbacked = false;
102 s->process_data_blocks = process_data_blocks;
106 EXPORT_SYMBOL(amdtp_stream_init);
109 * amdtp_stream_destroy - free stream resources
110 * @s: the AMDTP stream to destroy
112 void amdtp_stream_destroy(struct amdtp_stream *s)
114 /* Not initialized. */
115 if (s->protocol == NULL)
118 WARN_ON(amdtp_stream_running(s));
120 mutex_destroy(&s->mutex);
122 EXPORT_SYMBOL(amdtp_stream_destroy);
124 const unsigned int amdtp_syt_intervals[CIP_SFC_COUNT] = {
128 [CIP_SFC_88200] = 16,
129 [CIP_SFC_96000] = 16,
130 [CIP_SFC_176400] = 32,
131 [CIP_SFC_192000] = 32,
133 EXPORT_SYMBOL(amdtp_syt_intervals);
135 const unsigned int amdtp_rate_table[CIP_SFC_COUNT] = {
136 [CIP_SFC_32000] = 32000,
137 [CIP_SFC_44100] = 44100,
138 [CIP_SFC_48000] = 48000,
139 [CIP_SFC_88200] = 88200,
140 [CIP_SFC_96000] = 96000,
141 [CIP_SFC_176400] = 176400,
142 [CIP_SFC_192000] = 192000,
144 EXPORT_SYMBOL(amdtp_rate_table);
146 static int apply_constraint_to_size(struct snd_pcm_hw_params *params,
147 struct snd_pcm_hw_rule *rule)
149 struct snd_interval *s = hw_param_interval(params, rule->var);
150 const struct snd_interval *r =
151 hw_param_interval_c(params, SNDRV_PCM_HW_PARAM_RATE);
152 struct snd_interval t = {0};
153 unsigned int step = 0;
156 for (i = 0; i < CIP_SFC_COUNT; ++i) {
157 if (snd_interval_test(r, amdtp_rate_table[i]))
158 step = max(step, amdtp_syt_intervals[i]);
161 t.min = roundup(s->min, step);
162 t.max = rounddown(s->max, step);
165 return snd_interval_refine(s, &t);
169 * amdtp_stream_add_pcm_hw_constraints - add hw constraints for PCM substream
170 * @s: the AMDTP stream, which must be initialized.
171 * @runtime: the PCM substream runtime
173 int amdtp_stream_add_pcm_hw_constraints(struct amdtp_stream *s,
174 struct snd_pcm_runtime *runtime)
176 struct snd_pcm_hardware *hw = &runtime->hw;
179 hw->info = SNDRV_PCM_INFO_BATCH |
180 SNDRV_PCM_INFO_BLOCK_TRANSFER |
181 SNDRV_PCM_INFO_INTERLEAVED |
182 SNDRV_PCM_INFO_JOINT_DUPLEX |
183 SNDRV_PCM_INFO_MMAP |
184 SNDRV_PCM_INFO_MMAP_VALID;
186 /* SNDRV_PCM_INFO_BATCH */
188 hw->periods_max = UINT_MAX;
190 /* bytes for a frame */
191 hw->period_bytes_min = 4 * hw->channels_max;
193 /* Just to prevent from allocating much pages. */
194 hw->period_bytes_max = hw->period_bytes_min * 2048;
195 hw->buffer_bytes_max = hw->period_bytes_max * hw->periods_min;
198 * Currently firewire-lib processes 16 packets in one software
199 * interrupt callback. This equals to 2msec but actually the
200 * interval of the interrupts has a jitter.
201 * Additionally, even if adding a constraint to fit period size to
202 * 2msec, actual calculated frames per period doesn't equal to 2msec,
203 * depending on sampling rate.
204 * Anyway, the interval to call snd_pcm_period_elapsed() cannot 2msec.
205 * Here let us use 5msec for safe period interrupt.
207 err = snd_pcm_hw_constraint_minmax(runtime,
208 SNDRV_PCM_HW_PARAM_PERIOD_TIME,
213 /* Non-Blocking stream has no more constraints */
214 if (!(s->flags & CIP_BLOCKING))
218 * One AMDTP packet can include some frames. In blocking mode, the
219 * number equals to SYT_INTERVAL. So the number is 8, 16 or 32,
220 * depending on its sampling rate. For accurate period interrupt, it's
221 * preferrable to align period/buffer sizes to current SYT_INTERVAL.
223 err = snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_PERIOD_SIZE,
224 apply_constraint_to_size, NULL,
225 SNDRV_PCM_HW_PARAM_PERIOD_SIZE,
226 SNDRV_PCM_HW_PARAM_RATE, -1);
229 err = snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_BUFFER_SIZE,
230 apply_constraint_to_size, NULL,
231 SNDRV_PCM_HW_PARAM_BUFFER_SIZE,
232 SNDRV_PCM_HW_PARAM_RATE, -1);
238 EXPORT_SYMBOL(amdtp_stream_add_pcm_hw_constraints);
241 * amdtp_stream_set_parameters - set stream parameters
242 * @s: the AMDTP stream to configure
243 * @rate: the sample rate
244 * @data_block_quadlets: the size of a data block in quadlet unit
246 * The parameters must be set before the stream is started, and must not be
247 * changed while the stream is running.
249 int amdtp_stream_set_parameters(struct amdtp_stream *s, unsigned int rate,
250 unsigned int data_block_quadlets)
254 for (sfc = 0; sfc < ARRAY_SIZE(amdtp_rate_table); ++sfc) {
255 if (amdtp_rate_table[sfc] == rate)
258 if (sfc == ARRAY_SIZE(amdtp_rate_table))
262 s->data_block_quadlets = data_block_quadlets;
263 s->syt_interval = amdtp_syt_intervals[sfc];
265 // default buffering in the device.
266 if (s->direction == AMDTP_OUT_STREAM) {
267 s->ctx_data.rx.transfer_delay =
268 TRANSFER_DELAY_TICKS - TICKS_PER_CYCLE;
270 if (s->flags & CIP_BLOCKING) {
271 // additional buffering needed to adjust for no-data
273 s->ctx_data.rx.transfer_delay +=
274 TICKS_PER_SECOND * s->syt_interval / rate;
280 EXPORT_SYMBOL(amdtp_stream_set_parameters);
283 * amdtp_stream_get_max_payload - get the stream's packet size
284 * @s: the AMDTP stream
286 * This function must not be called before the stream has been configured
287 * with amdtp_stream_set_parameters().
289 unsigned int amdtp_stream_get_max_payload(struct amdtp_stream *s)
291 unsigned int multiplier = 1;
292 unsigned int cip_header_size = 0;
294 if (s->flags & CIP_JUMBO_PAYLOAD)
296 if (!(s->flags & CIP_NO_HEADER))
297 cip_header_size = sizeof(__be32) * 2;
299 return cip_header_size +
300 s->syt_interval * s->data_block_quadlets * sizeof(__be32) * multiplier;
302 EXPORT_SYMBOL(amdtp_stream_get_max_payload);
305 * amdtp_stream_pcm_prepare - prepare PCM device for running
306 * @s: the AMDTP stream
308 * This function should be called from the PCM device's .prepare callback.
310 void amdtp_stream_pcm_prepare(struct amdtp_stream *s)
312 tasklet_kill(&s->period_tasklet);
313 s->pcm_buffer_pointer = 0;
314 s->pcm_period_pointer = 0;
316 EXPORT_SYMBOL(amdtp_stream_pcm_prepare);
318 static unsigned int calculate_data_blocks(struct amdtp_stream *s,
321 unsigned int phase, data_blocks;
324 if (s->flags & CIP_BLOCKING) {
325 /* This module generate empty packet for 'no data'. */
326 if (syt == CIP_SYT_NO_INFO)
329 data_blocks = s->syt_interval;
330 /* Non-blocking mode. */
332 if (!cip_sfc_is_base_44100(s->sfc)) {
333 // Sample_rate / 8000 is an integer, and precomputed.
334 data_blocks = s->ctx_data.rx.data_block_state;
336 phase = s->ctx_data.rx.data_block_state;
339 * This calculates the number of data blocks per packet so that
340 * 1) the overall rate is correct and exactly synchronized to
342 * 2) packets with a rounded-up number of blocks occur as early
343 * as possible in the sequence (to prevent underruns of the
346 if (s->sfc == CIP_SFC_44100)
347 /* 6 6 5 6 5 6 5 ... */
348 data_blocks = 5 + ((phase & 1) ^
349 (phase == 0 || phase >= 40));
351 /* 12 11 11 11 11 ... or 23 22 22 22 22 ... */
352 data_blocks = 11 * (s->sfc >> 1) + (phase == 0);
353 if (++phase >= (80 >> (s->sfc >> 1)))
355 s->ctx_data.rx.data_block_state = phase;
362 static unsigned int calculate_syt(struct amdtp_stream *s,
365 unsigned int syt_offset, phase, index, syt;
367 if (s->ctx_data.rx.last_syt_offset < TICKS_PER_CYCLE) {
368 if (!cip_sfc_is_base_44100(s->sfc))
369 syt_offset = s->ctx_data.rx.last_syt_offset +
370 s->ctx_data.rx.syt_offset_state;
373 * The time, in ticks, of the n'th SYT_INTERVAL sample is:
374 * n * SYT_INTERVAL * 24576000 / sample_rate
375 * Modulo TICKS_PER_CYCLE, the difference between successive
376 * elements is about 1386.23. Rounding the results of this
377 * formula to the SYT precision results in a sequence of
378 * differences that begins with:
379 * 1386 1386 1387 1386 1386 1386 1387 1386 1386 1386 1387 ...
380 * This code generates _exactly_ the same sequence.
382 phase = s->ctx_data.rx.syt_offset_state;
384 syt_offset = s->ctx_data.rx.last_syt_offset;
385 syt_offset += 1386 + ((index && !(index & 3)) ||
389 s->ctx_data.rx.syt_offset_state = phase;
392 syt_offset = s->ctx_data.rx.last_syt_offset - TICKS_PER_CYCLE;
393 s->ctx_data.rx.last_syt_offset = syt_offset;
395 if (syt_offset < TICKS_PER_CYCLE) {
396 syt_offset += s->ctx_data.rx.transfer_delay;
397 syt = (cycle + syt_offset / TICKS_PER_CYCLE) << 12;
398 syt += syt_offset % TICKS_PER_CYCLE;
400 return syt & CIP_SYT_MASK;
402 return CIP_SYT_NO_INFO;
406 static void update_pcm_pointers(struct amdtp_stream *s,
407 struct snd_pcm_substream *pcm,
412 ptr = s->pcm_buffer_pointer + frames;
413 if (ptr >= pcm->runtime->buffer_size)
414 ptr -= pcm->runtime->buffer_size;
415 WRITE_ONCE(s->pcm_buffer_pointer, ptr);
417 s->pcm_period_pointer += frames;
418 if (s->pcm_period_pointer >= pcm->runtime->period_size) {
419 s->pcm_period_pointer -= pcm->runtime->period_size;
420 tasklet_hi_schedule(&s->period_tasklet);
424 static void pcm_period_tasklet(unsigned long data)
426 struct amdtp_stream *s = (void *)data;
427 struct snd_pcm_substream *pcm = READ_ONCE(s->pcm);
430 snd_pcm_period_elapsed(pcm);
433 static int queue_packet(struct amdtp_stream *s, struct fw_iso_packet *params)
437 params->interrupt = IS_ALIGNED(s->packet_index + 1, INTERRUPT_INTERVAL);
438 params->tag = s->tag;
441 err = fw_iso_context_queue(s->context, params, &s->buffer.iso_buffer,
442 s->buffer.packets[s->packet_index].offset);
444 dev_err(&s->unit->device, "queueing error: %d\n", err);
448 if (++s->packet_index >= QUEUE_LENGTH)
454 static inline int queue_out_packet(struct amdtp_stream *s,
455 struct fw_iso_packet *params,
456 unsigned int payload_length)
458 // No header for this packet.
459 params->header_length = 0;
460 params->payload_length = payload_length;
461 params->skip = !!(payload_length == 0);
462 return queue_packet(s, params);
465 static inline int queue_in_packet(struct amdtp_stream *s,
466 struct fw_iso_packet *params)
468 // Queue one packet for IR context.
469 params->header_length = s->ctx_data.tx.ctx_header_size;
470 params->payload_length = s->ctx_data.tx.max_ctx_payload_length;
471 params->skip = false;
472 return queue_packet(s, params);
475 static void generate_cip_header(struct amdtp_stream *s, __be32 cip_header[2],
478 cip_header[0] = cpu_to_be32(READ_ONCE(s->source_node_id_field) |
479 (s->data_block_quadlets << CIP_DBS_SHIFT) |
480 ((s->sph << CIP_SPH_SHIFT) & CIP_SPH_MASK) |
481 s->data_block_counter);
482 cip_header[1] = cpu_to_be32(CIP_EOH |
483 ((s->fmt << CIP_FMT_SHIFT) & CIP_FMT_MASK) |
484 ((s->ctx_data.rx.fdf << CIP_FDF_SHIFT) & CIP_FDF_MASK) |
485 (syt & CIP_SYT_MASK));
488 static int handle_out_packet(struct amdtp_stream *s, unsigned int cycle,
489 const __be32 *ctx_header, __be32 *buffer,
493 unsigned int data_blocks;
494 unsigned int payload_length;
496 unsigned int pcm_frames;
497 struct snd_pcm_substream *pcm;
498 struct fw_iso_packet params = {0};
500 syt = calculate_syt(s, cycle);
501 data_blocks = calculate_data_blocks(s, syt);
503 payload_length = data_blocks * sizeof(__be32) * s->data_block_quadlets;
504 if (!(s->flags & CIP_NO_HEADER)) {
507 payload_length += 2 * sizeof(__be32);
512 pcm_frames = s->process_data_blocks(s, buffer, data_blocks, &syt);
514 if (s->flags & CIP_DBC_IS_END_EVENT)
515 s->data_block_counter =
516 (s->data_block_counter + data_blocks) & 0xff;
519 generate_cip_header(s, cip_header, syt);
521 if (!(s->flags & CIP_DBC_IS_END_EVENT))
522 s->data_block_counter =
523 (s->data_block_counter + data_blocks) & 0xff;
525 trace_amdtp_packet(s, cycle, cip_header, payload_length, data_blocks,
528 if (queue_out_packet(s, ¶ms, payload_length) < 0)
531 pcm = READ_ONCE(s->pcm);
532 if (pcm && pcm_frames > 0)
533 update_pcm_pointers(s, pcm, pcm_frames);
538 static int check_cip_header(struct amdtp_stream *s, const __be32 *buf,
539 unsigned int payload_length,
540 unsigned int *data_blocks, unsigned int *syt)
546 unsigned int data_block_counter;
549 cip_header[0] = be32_to_cpu(buf[0]);
550 cip_header[1] = be32_to_cpu(buf[1]);
553 * This module supports 'Two-quadlet CIP header with SYT field'.
554 * For convenience, also check FMT field is AM824 or not.
556 if ((((cip_header[0] & CIP_EOH_MASK) == CIP_EOH) ||
557 ((cip_header[1] & CIP_EOH_MASK) != CIP_EOH)) &&
558 (!(s->flags & CIP_HEADER_WITHOUT_EOH))) {
559 dev_info_ratelimited(&s->unit->device,
560 "Invalid CIP header for AMDTP: %08X:%08X\n",
561 cip_header[0], cip_header[1]);
565 /* Check valid protocol or not. */
566 sph = (cip_header[0] & CIP_SPH_MASK) >> CIP_SPH_SHIFT;
567 fmt = (cip_header[1] & CIP_FMT_MASK) >> CIP_FMT_SHIFT;
568 if (sph != s->sph || fmt != s->fmt) {
569 dev_info_ratelimited(&s->unit->device,
570 "Detect unexpected protocol: %08x %08x\n",
571 cip_header[0], cip_header[1]);
575 /* Calculate data blocks */
576 fdf = (cip_header[1] & CIP_FDF_MASK) >> CIP_FDF_SHIFT;
577 if (payload_length < sizeof(__be32) * 2 ||
578 (fmt == CIP_FMT_AM && fdf == AMDTP_FDF_NO_DATA)) {
581 unsigned int data_block_quadlets =
582 (cip_header[0] & CIP_DBS_MASK) >> CIP_DBS_SHIFT;
583 /* avoid division by zero */
584 if (data_block_quadlets == 0) {
585 dev_err(&s->unit->device,
586 "Detect invalid value in dbs field: %08X\n",
590 if (s->flags & CIP_WRONG_DBS)
591 data_block_quadlets = s->data_block_quadlets;
593 *data_blocks = (payload_length / sizeof(__be32) - 2) /
597 /* Check data block counter continuity */
598 data_block_counter = cip_header[0] & CIP_DBC_MASK;
599 if (*data_blocks == 0 && (s->flags & CIP_EMPTY_HAS_WRONG_DBC) &&
600 s->data_block_counter != UINT_MAX)
601 data_block_counter = s->data_block_counter;
603 if (((s->flags & CIP_SKIP_DBC_ZERO_CHECK) &&
604 data_block_counter == s->ctx_data.tx.first_dbc) ||
605 s->data_block_counter == UINT_MAX) {
607 } else if (!(s->flags & CIP_DBC_IS_END_EVENT)) {
608 lost = data_block_counter != s->data_block_counter;
610 unsigned int dbc_interval;
612 if (*data_blocks > 0 && s->ctx_data.tx.dbc_interval > 0)
613 dbc_interval = s->ctx_data.tx.dbc_interval;
615 dbc_interval = *data_blocks;
617 lost = data_block_counter !=
618 ((s->data_block_counter + dbc_interval) & 0xff);
622 dev_err(&s->unit->device,
623 "Detect discontinuity of CIP: %02X %02X\n",
624 s->data_block_counter, data_block_counter);
628 *syt = cip_header[1] & CIP_SYT_MASK;
630 if (s->flags & CIP_DBC_IS_END_EVENT) {
631 s->data_block_counter = data_block_counter;
633 s->data_block_counter =
634 (data_block_counter + *data_blocks) & 0xff;
640 static int handle_in_packet(struct amdtp_stream *s, unsigned int cycle,
641 const __be32 *ctx_header, __be32 *buffer,
644 unsigned int payload_length;
645 const __be32 *cip_header;
647 unsigned int data_blocks;
648 struct snd_pcm_substream *pcm;
649 unsigned int pcm_frames;
650 struct fw_iso_packet params = {0};
653 payload_length = be32_to_cpu(ctx_header[0]) >> ISO_DATA_LENGTH_SHIFT;
654 if (payload_length > s->ctx_data.tx.ctx_header_size +
655 s->ctx_data.tx.max_ctx_payload_length) {
656 dev_err(&s->unit->device,
657 "Detect jumbo payload: %04x %04x\n",
658 payload_length, s->ctx_data.tx.max_ctx_payload_length);
662 cip_header = ctx_header + 2;
663 if (!(s->flags & CIP_NO_HEADER)) {
664 cip_header = &ctx_header[2];
665 err = check_cip_header(s, cip_header, payload_length,
675 data_blocks = payload_length / 4 / s->data_block_quadlets;
679 trace_amdtp_packet(s, cycle, cip_header, payload_length, data_blocks,
682 pcm_frames = s->process_data_blocks(s, buffer, data_blocks, &syt);
684 if (queue_in_packet(s, ¶ms) < 0)
687 pcm = READ_ONCE(s->pcm);
688 if (pcm && pcm_frames > 0)
689 update_pcm_pointers(s, pcm, pcm_frames);
694 // In CYCLE_TIMER register of IEEE 1394, 7 bits are used to represent second. On
695 // the other hand, in DMA descriptors of 1394 OHCI, 3 bits are used to represent
696 // it. Thus, via Linux firewire subsystem, we can get the 3 bits for second.
697 static inline u32 compute_cycle_count(__be32 ctx_header_tstamp)
699 u32 tstamp = be32_to_cpu(ctx_header_tstamp) & HEADER_TSTAMP_MASK;
700 return (((tstamp >> 13) & 0x07) * 8000) + (tstamp & 0x1fff);
703 static inline u32 increment_cycle_count(u32 cycle, unsigned int addend)
706 if (cycle >= 8 * CYCLES_PER_SECOND)
707 cycle -= 8 * CYCLES_PER_SECOND;
711 // Align to actual cycle count for the packet which is going to be scheduled.
712 // This module queued the same number of isochronous cycle as QUEUE_LENGTH to
713 // skip isochronous cycle, therefore it's OK to just increment the cycle by
714 // QUEUE_LENGTH for scheduled cycle.
715 static inline u32 compute_it_cycle(const __be32 ctx_header_tstamp)
717 u32 cycle = compute_cycle_count(ctx_header_tstamp);
718 return increment_cycle_count(cycle, QUEUE_LENGTH);
721 static inline void cancel_stream(struct amdtp_stream *s)
723 s->packet_index = -1;
725 amdtp_stream_pcm_abort(s);
726 WRITE_ONCE(s->pcm_buffer_pointer, SNDRV_PCM_POS_XRUN);
729 static void out_stream_callback(struct fw_iso_context *context, u32 tstamp,
730 size_t header_length, void *header,
733 struct amdtp_stream *s = private_data;
734 const __be32 *ctx_header = header;
735 unsigned int i, packets = header_length / sizeof(*ctx_header);
737 if (s->packet_index < 0)
740 for (i = 0; i < packets; ++i) {
744 cycle = compute_it_cycle(*ctx_header);
745 buffer = s->buffer.packets[s->packet_index].buffer;
747 if (handle_out_packet(s, cycle, ctx_header, buffer, i) < 0) {
755 fw_iso_context_queue_flush(s->context);
758 static void in_stream_callback(struct fw_iso_context *context, u32 tstamp,
759 size_t header_length, void *header,
762 struct amdtp_stream *s = private_data;
763 unsigned int i, packets;
764 __be32 *ctx_header = header;
766 if (s->packet_index < 0)
769 // The number of packets in buffer.
770 packets = header_length / s->ctx_data.tx.ctx_header_size;
772 for (i = 0; i < packets; i++) {
776 cycle = compute_cycle_count(ctx_header[1]);
777 buffer = s->buffer.packets[s->packet_index].buffer;
779 if (handle_in_packet(s, cycle, ctx_header, buffer, i) < 0)
782 ctx_header += s->ctx_data.tx.ctx_header_size / sizeof(*ctx_header);
785 /* Queueing error or detecting invalid payload. */
791 fw_iso_context_queue_flush(s->context);
794 /* this is executed one time */
795 static void amdtp_stream_first_callback(struct fw_iso_context *context,
796 u32 tstamp, size_t header_length,
797 void *header, void *private_data)
799 struct amdtp_stream *s = private_data;
800 const __be32 *ctx_header = header;
804 * For in-stream, first packet has come.
805 * For out-stream, prepared to transmit first packet
807 s->callbacked = true;
808 wake_up(&s->callback_wait);
810 if (s->direction == AMDTP_IN_STREAM) {
811 cycle = compute_cycle_count(ctx_header[1]);
813 context->callback.sc = in_stream_callback;
815 cycle = compute_it_cycle(*ctx_header);
817 context->callback.sc = out_stream_callback;
820 s->start_cycle = cycle;
822 context->callback.sc(context, tstamp, header_length, header, s);
826 * amdtp_stream_start - start transferring packets
827 * @s: the AMDTP stream to start
828 * @channel: the isochronous channel on the bus
829 * @speed: firewire speed code
831 * The stream cannot be started until it has been configured with
832 * amdtp_stream_set_parameters() and it must be started before any PCM or MIDI
833 * device can be started.
835 int amdtp_stream_start(struct amdtp_stream *s, int channel, int speed)
837 static const struct {
838 unsigned int data_block;
839 unsigned int syt_offset;
840 } *entry, initial_state[] = {
841 [CIP_SFC_32000] = { 4, 3072 },
842 [CIP_SFC_48000] = { 6, 1024 },
843 [CIP_SFC_96000] = { 12, 1024 },
844 [CIP_SFC_192000] = { 24, 1024 },
845 [CIP_SFC_44100] = { 0, 67 },
846 [CIP_SFC_88200] = { 0, 67 },
847 [CIP_SFC_176400] = { 0, 67 },
849 unsigned int ctx_header_size;
850 unsigned int max_ctx_payload_size;
851 enum dma_data_direction dir;
854 mutex_lock(&s->mutex);
856 if (WARN_ON(amdtp_stream_running(s) ||
857 (s->data_block_quadlets < 1))) {
862 if (s->direction == AMDTP_IN_STREAM) {
863 s->data_block_counter = UINT_MAX;
865 entry = &initial_state[s->sfc];
867 s->data_block_counter = 0;
868 s->ctx_data.rx.data_block_state = entry->data_block;
869 s->ctx_data.rx.syt_offset_state = entry->syt_offset;
870 s->ctx_data.rx.last_syt_offset = TICKS_PER_CYCLE;
873 /* initialize packet buffer */
874 if (s->direction == AMDTP_IN_STREAM) {
875 dir = DMA_FROM_DEVICE;
876 type = FW_ISO_CONTEXT_RECEIVE;
877 if (!(s->flags & CIP_NO_HEADER))
878 ctx_header_size = IR_CTX_HEADER_SIZE_CIP;
880 ctx_header_size = IR_CTX_HEADER_SIZE_NO_CIP;
883 type = FW_ISO_CONTEXT_TRANSMIT;
884 ctx_header_size = 0; // No effect for IT context.
887 max_ctx_payload_size = amdtp_stream_get_max_payload(s) -
890 err = iso_packets_buffer_init(&s->buffer, s->unit, QUEUE_LENGTH,
891 max_ctx_payload_size, dir);
895 s->context = fw_iso_context_create(fw_parent_device(s->unit)->card,
896 type, channel, speed, ctx_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);
908 if (s->direction == AMDTP_IN_STREAM) {
909 s->ctx_data.tx.max_ctx_payload_length = max_ctx_payload_size;
910 s->ctx_data.tx.ctx_header_size = ctx_header_size;
913 if (s->flags & CIP_NO_HEADER)
914 s->tag = TAG_NO_CIP_HEADER;
920 struct fw_iso_packet params;
921 if (s->direction == AMDTP_IN_STREAM)
922 err = queue_in_packet(s, ¶ms);
924 err = queue_out_packet(s, ¶ms, 0);
927 } while (s->packet_index > 0);
929 /* NOTE: TAG1 matches CIP. This just affects in stream. */
930 tag = FW_ISO_CONTEXT_MATCH_TAG1;
931 if ((s->flags & CIP_EMPTY_WITH_TAG0) || (s->flags & CIP_NO_HEADER))
932 tag |= FW_ISO_CONTEXT_MATCH_TAG0;
934 s->callbacked = false;
935 err = fw_iso_context_start(s->context, -1, 0, tag);
939 mutex_unlock(&s->mutex);
944 fw_iso_context_destroy(s->context);
945 s->context = ERR_PTR(-1);
947 iso_packets_buffer_destroy(&s->buffer, s->unit);
949 mutex_unlock(&s->mutex);
953 EXPORT_SYMBOL(amdtp_stream_start);
956 * amdtp_stream_pcm_pointer - get the PCM buffer position
957 * @s: the AMDTP stream that transports the PCM data
959 * Returns the current buffer position, in frames.
961 unsigned long amdtp_stream_pcm_pointer(struct amdtp_stream *s)
964 * This function is called in software IRQ context of period_tasklet or
967 * When the software IRQ context was scheduled by software IRQ context
968 * of IR/IT contexts, queued packets were already handled. Therefore,
969 * no need to flush the queue in buffer anymore.
971 * When the process context reach here, some packets will be already
972 * queued in the buffer. These packets should be handled immediately
973 * to keep better granularity of PCM pointer.
975 * Later, the process context will sometimes schedules software IRQ
976 * context of the period_tasklet. Then, no need to flush the queue by
977 * the same reason as described for IR/IT contexts.
979 if (!in_interrupt() && amdtp_stream_running(s))
980 fw_iso_context_flush_completions(s->context);
982 return READ_ONCE(s->pcm_buffer_pointer);
984 EXPORT_SYMBOL(amdtp_stream_pcm_pointer);
987 * amdtp_stream_pcm_ack - acknowledge queued PCM frames
988 * @s: the AMDTP stream that transfers the PCM frames
990 * Returns zero always.
992 int amdtp_stream_pcm_ack(struct amdtp_stream *s)
995 * Process isochronous packets for recent isochronous cycle to handle
998 if (amdtp_stream_running(s))
999 fw_iso_context_flush_completions(s->context);
1003 EXPORT_SYMBOL(amdtp_stream_pcm_ack);
1006 * amdtp_stream_update - update the stream after a bus reset
1007 * @s: the AMDTP stream
1009 void amdtp_stream_update(struct amdtp_stream *s)
1012 WRITE_ONCE(s->source_node_id_field,
1013 (fw_parent_device(s->unit)->card->node_id << CIP_SID_SHIFT) & CIP_SID_MASK);
1015 EXPORT_SYMBOL(amdtp_stream_update);
1018 * amdtp_stream_stop - stop sending packets
1019 * @s: the AMDTP stream to stop
1021 * All PCM and MIDI devices of the stream must be stopped before the stream
1022 * itself can be stopped.
1024 void amdtp_stream_stop(struct amdtp_stream *s)
1026 mutex_lock(&s->mutex);
1028 if (!amdtp_stream_running(s)) {
1029 mutex_unlock(&s->mutex);
1033 tasklet_kill(&s->period_tasklet);
1034 fw_iso_context_stop(s->context);
1035 fw_iso_context_destroy(s->context);
1036 s->context = ERR_PTR(-1);
1037 iso_packets_buffer_destroy(&s->buffer, s->unit);
1039 s->callbacked = false;
1041 mutex_unlock(&s->mutex);
1043 EXPORT_SYMBOL(amdtp_stream_stop);
1046 * amdtp_stream_pcm_abort - abort the running PCM device
1047 * @s: the AMDTP stream about to be stopped
1049 * If the isochronous stream needs to be stopped asynchronously, call this
1050 * function first to stop the PCM device.
1052 void amdtp_stream_pcm_abort(struct amdtp_stream *s)
1054 struct snd_pcm_substream *pcm;
1056 pcm = READ_ONCE(s->pcm);
1058 snd_pcm_stop_xrun(pcm);
1060 EXPORT_SYMBOL(amdtp_stream_pcm_abort);