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Clemens Ladisch31ef9132011-03-15 07:53:21 +01001/*
2 * Audio and Music Data Transmission Protocol (IEC 61883-6) streams
3 * with Common Isochronous Packet (IEC 61883-1) headers
4 *
5 * Copyright (c) Clemens Ladisch <clemens@ladisch.de>
6 * Licensed under the terms of the GNU General Public License, version 2.
7 */
8
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 "amdtp.h"
16
17#define TICKS_PER_CYCLE 3072
18#define CYCLES_PER_SECOND 8000
19#define TICKS_PER_SECOND (TICKS_PER_CYCLE * CYCLES_PER_SECOND)
20
21#define TRANSFER_DELAY_TICKS 0x2e00 /* 479.17 µs */
22
23#define TAG_CIP 1
24
25#define CIP_EOH (1u << 31)
26#define CIP_FMT_AM (0x10 << 24)
27#define AMDTP_FDF_AM824 (0 << 19)
28#define AMDTP_FDF_SFC_SHIFT 16
29
30/* TODO: make these configurable */
31#define INTERRUPT_INTERVAL 16
32#define QUEUE_LENGTH 48
33
34/**
35 * amdtp_out_stream_init - initialize an AMDTP output stream structure
36 * @s: the AMDTP output stream to initialize
37 * @unit: the target of the stream
38 * @flags: the packet transmission method to use
39 */
40int amdtp_out_stream_init(struct amdtp_out_stream *s, struct fw_unit *unit,
41 enum cip_out_flags flags)
42{
43 if (flags != CIP_NONBLOCKING)
44 return -EINVAL;
45
46 s->unit = fw_unit_get(unit);
47 s->flags = flags;
48 s->context = ERR_PTR(-1);
49 mutex_init(&s->mutex);
Clemens Ladischec00f5e2011-03-15 07:57:24 +010050 s->packet_index = 0;
Clemens Ladisch31ef9132011-03-15 07:53:21 +010051
52 return 0;
53}
54EXPORT_SYMBOL(amdtp_out_stream_init);
55
56/**
57 * amdtp_out_stream_destroy - free stream resources
58 * @s: the AMDTP output stream to destroy
59 */
60void amdtp_out_stream_destroy(struct amdtp_out_stream *s)
61{
62 WARN_ON(!IS_ERR(s->context));
63 mutex_destroy(&s->mutex);
64 fw_unit_put(s->unit);
65}
66EXPORT_SYMBOL(amdtp_out_stream_destroy);
67
68/**
69 * amdtp_out_stream_set_rate - set the sample rate
70 * @s: the AMDTP output stream to configure
71 * @rate: the sample rate
72 *
73 * The sample rate must be set before the stream is started, and must not be
74 * changed while the stream is running.
75 */
76void amdtp_out_stream_set_rate(struct amdtp_out_stream *s, unsigned int rate)
77{
78 static const struct {
79 unsigned int rate;
80 unsigned int syt_interval;
81 } rate_info[] = {
82 [CIP_SFC_32000] = { 32000, 8, },
83 [CIP_SFC_44100] = { 44100, 8, },
84 [CIP_SFC_48000] = { 48000, 8, },
85 [CIP_SFC_88200] = { 88200, 16, },
86 [CIP_SFC_96000] = { 96000, 16, },
87 [CIP_SFC_176400] = { 176400, 32, },
88 [CIP_SFC_192000] = { 192000, 32, },
89 };
90 unsigned int sfc;
91
92 if (WARN_ON(!IS_ERR(s->context)))
93 return;
94
95 for (sfc = 0; sfc < ARRAY_SIZE(rate_info); ++sfc)
96 if (rate_info[sfc].rate == rate) {
97 s->sfc = sfc;
98 s->syt_interval = rate_info[sfc].syt_interval;
99 return;
100 }
101 WARN_ON(1);
102}
103EXPORT_SYMBOL(amdtp_out_stream_set_rate);
104
105/**
106 * amdtp_out_stream_get_max_payload - get the stream's packet size
107 * @s: the AMDTP output stream
108 *
109 * This function must not be called before the stream has been configured
110 * with amdtp_out_stream_set_hw_params(), amdtp_out_stream_set_pcm(), and
111 * amdtp_out_stream_set_midi().
112 */
113unsigned int amdtp_out_stream_get_max_payload(struct amdtp_out_stream *s)
114{
115 static const unsigned int max_data_blocks[] = {
116 [CIP_SFC_32000] = 4,
117 [CIP_SFC_44100] = 6,
118 [CIP_SFC_48000] = 6,
119 [CIP_SFC_88200] = 12,
120 [CIP_SFC_96000] = 12,
121 [CIP_SFC_176400] = 23,
122 [CIP_SFC_192000] = 24,
123 };
124
125 s->data_block_quadlets = s->pcm_channels;
126 s->data_block_quadlets += DIV_ROUND_UP(s->midi_ports, 8);
127
128 return 8 + max_data_blocks[s->sfc] * 4 * s->data_block_quadlets;
129}
130EXPORT_SYMBOL(amdtp_out_stream_get_max_payload);
131
132static void amdtp_write_s16(struct amdtp_out_stream *s,
133 struct snd_pcm_substream *pcm,
134 __be32 *buffer, unsigned int frames);
135static void amdtp_write_s32(struct amdtp_out_stream *s,
136 struct snd_pcm_substream *pcm,
137 __be32 *buffer, unsigned int frames);
138
139/**
140 * amdtp_out_stream_set_pcm_format - set the PCM format
141 * @s: the AMDTP output stream to configure
142 * @format: the format of the ALSA PCM device
143 *
144 * The sample format must be set before the stream is started, and must not be
145 * changed while the stream is running.
146 */
147void amdtp_out_stream_set_pcm_format(struct amdtp_out_stream *s,
148 snd_pcm_format_t format)
149{
150 if (WARN_ON(!IS_ERR(s->context)))
151 return;
152
153 switch (format) {
154 default:
155 WARN_ON(1);
156 /* fall through */
157 case SNDRV_PCM_FORMAT_S16:
158 s->transfer_samples = amdtp_write_s16;
159 break;
160 case SNDRV_PCM_FORMAT_S32:
161 s->transfer_samples = amdtp_write_s32;
162 break;
163 }
164}
165EXPORT_SYMBOL(amdtp_out_stream_set_pcm_format);
166
167static unsigned int calculate_data_blocks(struct amdtp_out_stream *s)
168{
169 unsigned int phase, data_blocks;
170
171 if (!cip_sfc_is_base_44100(s->sfc)) {
172 /* Sample_rate / 8000 is an integer, and precomputed. */
173 data_blocks = s->data_block_state;
174 } else {
175 phase = s->data_block_state;
176
177 /*
178 * This calculates the number of data blocks per packet so that
179 * 1) the overall rate is correct and exactly synchronized to
180 * the bus clock, and
181 * 2) packets with a rounded-up number of blocks occur as early
182 * as possible in the sequence (to prevent underruns of the
183 * device's buffer).
184 */
185 if (s->sfc == CIP_SFC_44100)
186 /* 6 6 5 6 5 6 5 ... */
187 data_blocks = 5 + ((phase & 1) ^
188 (phase == 0 || phase >= 40));
189 else
190 /* 12 11 11 11 11 ... or 23 22 22 22 22 ... */
191 data_blocks = 11 * (s->sfc >> 1) + (phase == 0);
192 if (++phase >= (80 >> (s->sfc >> 1)))
193 phase = 0;
194 s->data_block_state = phase;
195 }
196
197 return data_blocks;
198}
199
200static unsigned int calculate_syt(struct amdtp_out_stream *s,
201 unsigned int cycle)
202{
203 unsigned int syt_offset, phase, index, syt;
204
205 if (s->last_syt_offset < TICKS_PER_CYCLE) {
206 if (!cip_sfc_is_base_44100(s->sfc))
207 syt_offset = s->last_syt_offset + s->syt_offset_state;
208 else {
209 /*
210 * The time, in ticks, of the n'th SYT_INTERVAL sample is:
211 * n * SYT_INTERVAL * 24576000 / sample_rate
212 * Modulo TICKS_PER_CYCLE, the difference between successive
213 * elements is about 1386.23. Rounding the results of this
214 * formula to the SYT precision results in a sequence of
215 * differences that begins with:
216 * 1386 1386 1387 1386 1386 1386 1387 1386 1386 1386 1387 ...
217 * This code generates _exactly_ the same sequence.
218 */
219 phase = s->syt_offset_state;
220 index = phase % 13;
221 syt_offset = s->last_syt_offset;
222 syt_offset += 1386 + ((index && !(index & 3)) ||
223 phase == 146);
224 if (++phase >= 147)
225 phase = 0;
226 s->syt_offset_state = phase;
227 }
228 } else
229 syt_offset = s->last_syt_offset - TICKS_PER_CYCLE;
230 s->last_syt_offset = syt_offset;
231
Clemens Ladischbe454362011-03-15 07:55:02 +0100232 if (syt_offset < TICKS_PER_CYCLE) {
233 syt_offset += TRANSFER_DELAY_TICKS - TICKS_PER_CYCLE;
234 syt = (cycle + syt_offset / TICKS_PER_CYCLE) << 12;
235 syt += syt_offset % TICKS_PER_CYCLE;
Clemens Ladisch31ef9132011-03-15 07:53:21 +0100236
Clemens Ladischbe454362011-03-15 07:55:02 +0100237 return syt & 0xffff;
238 } else {
239 return 0xffff; /* no info */
240 }
Clemens Ladisch31ef9132011-03-15 07:53:21 +0100241}
242
243static void amdtp_write_s32(struct amdtp_out_stream *s,
244 struct snd_pcm_substream *pcm,
245 __be32 *buffer, unsigned int frames)
246{
247 struct snd_pcm_runtime *runtime = pcm->runtime;
248 unsigned int channels, remaining_frames, frame_step, i, c;
249 const u32 *src;
250
251 channels = s->pcm_channels;
252 src = (void *)runtime->dma_area +
253 s->pcm_buffer_pointer * (runtime->frame_bits / 8);
254 remaining_frames = runtime->buffer_size - s->pcm_buffer_pointer;
255 frame_step = s->data_block_quadlets - channels;
256
257 for (i = 0; i < frames; ++i) {
258 for (c = 0; c < channels; ++c) {
259 *buffer = cpu_to_be32((*src >> 8) | 0x40000000);
260 src++;
261 buffer++;
262 }
263 buffer += frame_step;
264 if (--remaining_frames == 0)
265 src = (void *)runtime->dma_area;
266 }
267}
268
269static void amdtp_write_s16(struct amdtp_out_stream *s,
270 struct snd_pcm_substream *pcm,
271 __be32 *buffer, unsigned int frames)
272{
273 struct snd_pcm_runtime *runtime = pcm->runtime;
274 unsigned int channels, remaining_frames, frame_step, i, c;
275 const u16 *src;
276
277 channels = s->pcm_channels;
278 src = (void *)runtime->dma_area +
279 s->pcm_buffer_pointer * (runtime->frame_bits / 8);
280 remaining_frames = runtime->buffer_size - s->pcm_buffer_pointer;
281 frame_step = s->data_block_quadlets - channels;
282
283 for (i = 0; i < frames; ++i) {
284 for (c = 0; c < channels; ++c) {
285 *buffer = cpu_to_be32((*src << 8) | 0x40000000);
286 src++;
287 buffer++;
288 }
289 buffer += frame_step;
290 if (--remaining_frames == 0)
291 src = (void *)runtime->dma_area;
292 }
293}
294
295static void amdtp_fill_pcm_silence(struct amdtp_out_stream *s,
296 __be32 *buffer, unsigned int frames)
297{
298 unsigned int i, c;
299
300 for (i = 0; i < frames; ++i) {
301 for (c = 0; c < s->pcm_channels; ++c)
302 buffer[c] = cpu_to_be32(0x40000000);
303 buffer += s->data_block_quadlets;
304 }
305}
306
307static void amdtp_fill_midi(struct amdtp_out_stream *s,
308 __be32 *buffer, unsigned int frames)
309{
310 unsigned int i;
311
312 for (i = 0; i < frames; ++i)
313 buffer[s->pcm_channels + i * s->data_block_quadlets] =
314 cpu_to_be32(0x80000000);
315}
316
317static void queue_out_packet(struct amdtp_out_stream *s, unsigned int cycle)
318{
319 __be32 *buffer;
Clemens Ladischec00f5e2011-03-15 07:57:24 +0100320 unsigned int index, data_blocks, syt, ptr;
Clemens Ladisch31ef9132011-03-15 07:53:21 +0100321 struct snd_pcm_substream *pcm;
322 struct fw_iso_packet packet;
323 int err;
324
Clemens Ladischec00f5e2011-03-15 07:57:24 +0100325 if (s->packet_index < 0)
326 return;
327 index = s->packet_index;
328
Clemens Ladisch31ef9132011-03-15 07:53:21 +0100329 data_blocks = calculate_data_blocks(s);
330 syt = calculate_syt(s, cycle);
331
Clemens Ladischec00f5e2011-03-15 07:57:24 +0100332 buffer = s->buffer.packets[index].buffer;
Clemens Ladisch31ef9132011-03-15 07:53:21 +0100333 buffer[0] = cpu_to_be32(ACCESS_ONCE(s->source_node_id_field) |
334 (s->data_block_quadlets << 16) |
335 s->data_block_counter);
336 buffer[1] = cpu_to_be32(CIP_EOH | CIP_FMT_AM | AMDTP_FDF_AM824 |
337 (s->sfc << AMDTP_FDF_SFC_SHIFT) | syt);
338 buffer += 2;
339
340 pcm = ACCESS_ONCE(s->pcm);
341 if (pcm)
342 s->transfer_samples(s, pcm, buffer, data_blocks);
343 else
344 amdtp_fill_pcm_silence(s, buffer, data_blocks);
345 if (s->midi_ports)
346 amdtp_fill_midi(s, buffer, data_blocks);
347
348 s->data_block_counter = (s->data_block_counter + data_blocks) & 0xff;
349
350 packet.payload_length = 8 + data_blocks * 4 * s->data_block_quadlets;
Clemens Ladischec00f5e2011-03-15 07:57:24 +0100351 packet.interrupt = IS_ALIGNED(index + 1, INTERRUPT_INTERVAL);
Clemens Ladisch31ef9132011-03-15 07:53:21 +0100352 packet.skip = 0;
353 packet.tag = TAG_CIP;
354 packet.sy = 0;
355 packet.header_length = 0;
356
357 err = fw_iso_context_queue(s->context, &packet, &s->buffer.iso_buffer,
Clemens Ladischec00f5e2011-03-15 07:57:24 +0100358 s->buffer.packets[index].offset);
359 if (err < 0) {
Clemens Ladisch31ef9132011-03-15 07:53:21 +0100360 dev_err(&s->unit->device, "queueing error: %d\n", err);
Clemens Ladischec00f5e2011-03-15 07:57:24 +0100361 s->packet_index = -1;
362 amdtp_out_stream_pcm_abort(s);
363 return;
364 }
Clemens Ladisch31ef9132011-03-15 07:53:21 +0100365
Clemens Ladischec00f5e2011-03-15 07:57:24 +0100366 if (++index >= QUEUE_LENGTH)
367 index = 0;
368 s->packet_index = index;
Clemens Ladisch31ef9132011-03-15 07:53:21 +0100369
370 if (pcm) {
371 ptr = s->pcm_buffer_pointer + data_blocks;
372 if (ptr >= pcm->runtime->buffer_size)
373 ptr -= pcm->runtime->buffer_size;
374 ACCESS_ONCE(s->pcm_buffer_pointer) = ptr;
375
376 s->pcm_period_pointer += data_blocks;
377 if (s->pcm_period_pointer >= pcm->runtime->period_size) {
378 s->pcm_period_pointer -= pcm->runtime->period_size;
379 snd_pcm_period_elapsed(pcm);
380 }
381 }
382}
383
384static void out_packet_callback(struct fw_iso_context *context, u32 cycle,
385 size_t header_length, void *header, void *data)
386{
387 struct amdtp_out_stream *s = data;
388 unsigned int i, packets = header_length / 4;
389
390 /*
391 * Compute the cycle of the last queued packet.
392 * (We need only the four lowest bits for the SYT, so we can ignore
393 * that bits 0-11 must wrap around at 3072.)
394 */
395 cycle += QUEUE_LENGTH - packets;
396
397 for (i = 0; i < packets; ++i)
398 queue_out_packet(s, ++cycle);
399}
400
401static int queue_initial_skip_packets(struct amdtp_out_stream *s)
402{
403 struct fw_iso_packet skip_packet = {
404 .skip = 1,
405 };
406 unsigned int i;
407 int err;
408
409 for (i = 0; i < QUEUE_LENGTH; ++i) {
Clemens Ladischec00f5e2011-03-15 07:57:24 +0100410 skip_packet.interrupt = IS_ALIGNED(s->packet_index + 1,
Clemens Ladisch31ef9132011-03-15 07:53:21 +0100411 INTERRUPT_INTERVAL);
412 err = fw_iso_context_queue(s->context, &skip_packet, NULL, 0);
413 if (err < 0)
414 return err;
Clemens Ladischec00f5e2011-03-15 07:57:24 +0100415 if (++s->packet_index >= QUEUE_LENGTH)
416 s->packet_index = 0;
Clemens Ladisch31ef9132011-03-15 07:53:21 +0100417 }
418
419 return 0;
420}
421
422/**
423 * amdtp_out_stream_start - start sending packets
424 * @s: the AMDTP output stream to start
425 * @channel: the isochronous channel on the bus
426 * @speed: firewire speed code
427 *
428 * The stream cannot be started until it has been configured with
429 * amdtp_out_stream_set_hw_params(), amdtp_out_stream_set_pcm(), and
430 * amdtp_out_stream_set_midi(); and it must be started before any
431 * PCM or MIDI device can be started.
432 */
433int amdtp_out_stream_start(struct amdtp_out_stream *s, int channel, int speed)
434{
435 static const struct {
436 unsigned int data_block;
437 unsigned int syt_offset;
438 } initial_state[] = {
439 [CIP_SFC_32000] = { 4, 3072 },
440 [CIP_SFC_48000] = { 6, 1024 },
441 [CIP_SFC_96000] = { 12, 1024 },
442 [CIP_SFC_192000] = { 24, 1024 },
443 [CIP_SFC_44100] = { 0, 67 },
444 [CIP_SFC_88200] = { 0, 67 },
445 [CIP_SFC_176400] = { 0, 67 },
446 };
447 int err;
448
449 mutex_lock(&s->mutex);
450
451 if (WARN_ON(!IS_ERR(s->context) ||
452 (!s->pcm_channels && !s->midi_ports))) {
453 err = -EBADFD;
454 goto err_unlock;
455 }
456
457 s->data_block_state = initial_state[s->sfc].data_block;
458 s->syt_offset_state = initial_state[s->sfc].syt_offset;
459 s->last_syt_offset = TICKS_PER_CYCLE;
460
461 err = iso_packets_buffer_init(&s->buffer, s->unit, QUEUE_LENGTH,
462 amdtp_out_stream_get_max_payload(s),
463 DMA_TO_DEVICE);
464 if (err < 0)
465 goto err_unlock;
466
467 s->context = fw_iso_context_create(fw_parent_device(s->unit)->card,
468 FW_ISO_CONTEXT_TRANSMIT,
469 channel, speed, 0,
470 out_packet_callback, s);
471 if (IS_ERR(s->context)) {
472 err = PTR_ERR(s->context);
473 if (err == -EBUSY)
474 dev_err(&s->unit->device,
475 "no free output stream on this controller\n");
476 goto err_buffer;
477 }
478
479 amdtp_out_stream_update(s);
480
Clemens Ladischec00f5e2011-03-15 07:57:24 +0100481 s->packet_index = 0;
Clemens Ladisch31ef9132011-03-15 07:53:21 +0100482 s->data_block_counter = 0;
483 err = queue_initial_skip_packets(s);
484 if (err < 0)
485 goto err_context;
486
487 err = fw_iso_context_start(s->context, -1, 0, 0);
488 if (err < 0)
489 goto err_context;
490
491 mutex_unlock(&s->mutex);
492
493 return 0;
494
495err_context:
496 fw_iso_context_destroy(s->context);
497 s->context = ERR_PTR(-1);
498err_buffer:
499 iso_packets_buffer_destroy(&s->buffer, s->unit);
500err_unlock:
501 mutex_unlock(&s->mutex);
502
503 return err;
504}
505EXPORT_SYMBOL(amdtp_out_stream_start);
506
507/**
508 * amdtp_out_stream_update - update the stream after a bus reset
509 * @s: the AMDTP output stream
510 */
511void amdtp_out_stream_update(struct amdtp_out_stream *s)
512{
513 ACCESS_ONCE(s->source_node_id_field) =
514 (fw_parent_device(s->unit)->card->node_id & 0x3f) << 24;
515}
516EXPORT_SYMBOL(amdtp_out_stream_update);
517
518/**
519 * amdtp_out_stream_stop - stop sending packets
520 * @s: the AMDTP output stream to stop
521 *
522 * All PCM and MIDI devices of the stream must be stopped before the stream
523 * itself can be stopped.
524 */
525void amdtp_out_stream_stop(struct amdtp_out_stream *s)
526{
527 mutex_lock(&s->mutex);
528
529 if (IS_ERR(s->context)) {
530 mutex_unlock(&s->mutex);
531 return;
532 }
533
534 fw_iso_context_stop(s->context);
535 fw_iso_context_destroy(s->context);
536 s->context = ERR_PTR(-1);
537 iso_packets_buffer_destroy(&s->buffer, s->unit);
538
539 mutex_unlock(&s->mutex);
540}
541EXPORT_SYMBOL(amdtp_out_stream_stop);
542
543/**
544 * amdtp_out_stream_pcm_abort - abort the running PCM device
545 * @s: the AMDTP stream about to be stopped
546 *
547 * If the isochronous stream needs to be stopped asynchronously, call this
548 * function first to stop the PCM device.
549 */
550void amdtp_out_stream_pcm_abort(struct amdtp_out_stream *s)
551{
552 struct snd_pcm_substream *pcm;
553
554 pcm = ACCESS_ONCE(s->pcm);
555 if (pcm) {
556 snd_pcm_stream_lock_irq(pcm);
557 if (snd_pcm_running(pcm))
558 snd_pcm_stop(pcm, SNDRV_PCM_STATE_XRUN);
559 snd_pcm_stream_unlock_irq(pcm);
560 }
561}
562EXPORT_SYMBOL(amdtp_out_stream_pcm_abort);