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
);