linux/sound/firewire/amdtp-stream.c
Takashi Sakamoto ff38e0c70a ALSA: firewire-lib: drop skip argument from helper functions to queue a packet
On most of audio and music units on IEEE 1394 bus which ALSA firewire stack
supports (or plans to support), CIP with two quadlets header is used.
Thus, there's no cases to queue packets with blank payload. If such packets
are going to be queued, it means that they're for skips of the cycle.

This commit simplifies helper functions to queue a packet.

Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Acked-by: Clemens Ladisch <clemens@ladisch.de>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
2016-05-11 20:36:28 +02:00

886 lines
24 KiB
C

/*
* Audio and Music Data Transmission Protocol (IEC 61883-6) streams
* with Common Isochronous Packet (IEC 61883-1) headers
*
* Copyright (c) Clemens Ladisch <clemens@ladisch.de>
* Licensed under the terms of the GNU General Public License, version 2.
*/
#include <linux/device.h>
#include <linux/err.h>
#include <linux/firewire.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <sound/pcm.h>
#include <sound/pcm_params.h>
#include "amdtp-stream.h"
#define TICKS_PER_CYCLE 3072
#define CYCLES_PER_SECOND 8000
#define TICKS_PER_SECOND (TICKS_PER_CYCLE * CYCLES_PER_SECOND)
/* Always support Linux tracing subsystem. */
#define CREATE_TRACE_POINTS
#include "amdtp-stream-trace.h"
#define TRANSFER_DELAY_TICKS 0x2e00 /* 479.17 microseconds */
/* isochronous header parameters */
#define ISO_DATA_LENGTH_SHIFT 16
#define TAG_CIP 1
/* common isochronous packet header parameters */
#define CIP_EOH_SHIFT 31
#define CIP_EOH (1u << CIP_EOH_SHIFT)
#define CIP_EOH_MASK 0x80000000
#define CIP_SID_SHIFT 24
#define CIP_SID_MASK 0x3f000000
#define CIP_DBS_MASK 0x00ff0000
#define CIP_DBS_SHIFT 16
#define CIP_DBC_MASK 0x000000ff
#define CIP_FMT_SHIFT 24
#define CIP_FMT_MASK 0x3f000000
#define CIP_FDF_MASK 0x00ff0000
#define CIP_FDF_SHIFT 16
#define CIP_SYT_MASK 0x0000ffff
#define CIP_SYT_NO_INFO 0xffff
/* Audio and Music transfer protocol specific parameters */
#define CIP_FMT_AM 0x10
#define AMDTP_FDF_NO_DATA 0xff
/* TODO: make these configurable */
#define INTERRUPT_INTERVAL 16
#define QUEUE_LENGTH 48
#define IN_PACKET_HEADER_SIZE 4
#define OUT_PACKET_HEADER_SIZE 0
static void pcm_period_tasklet(unsigned long data);
/**
* amdtp_stream_init - initialize an AMDTP stream structure
* @s: the AMDTP stream to initialize
* @unit: the target of the stream
* @dir: the direction of stream
* @flags: the packet transmission method to use
* @fmt: the value of fmt field in CIP header
* @process_data_blocks: callback handler to process data blocks
* @protocol_size: the size to allocate newly for protocol
*/
int amdtp_stream_init(struct amdtp_stream *s, struct fw_unit *unit,
enum amdtp_stream_direction dir, enum cip_flags flags,
unsigned int fmt,
amdtp_stream_process_data_blocks_t process_data_blocks,
unsigned int protocol_size)
{
if (process_data_blocks == NULL)
return -EINVAL;
s->protocol = kzalloc(protocol_size, GFP_KERNEL);
if (!s->protocol)
return -ENOMEM;
s->unit = unit;
s->direction = dir;
s->flags = flags;
s->context = ERR_PTR(-1);
mutex_init(&s->mutex);
tasklet_init(&s->period_tasklet, pcm_period_tasklet, (unsigned long)s);
s->packet_index = 0;
init_waitqueue_head(&s->callback_wait);
s->callbacked = false;
s->fmt = fmt;
s->process_data_blocks = process_data_blocks;
return 0;
}
EXPORT_SYMBOL(amdtp_stream_init);
/**
* amdtp_stream_destroy - free stream resources
* @s: the AMDTP stream to destroy
*/
void amdtp_stream_destroy(struct amdtp_stream *s)
{
/* Not initialized. */
if (s->protocol == NULL)
return;
WARN_ON(amdtp_stream_running(s));
kfree(s->protocol);
mutex_destroy(&s->mutex);
}
EXPORT_SYMBOL(amdtp_stream_destroy);
const unsigned int amdtp_syt_intervals[CIP_SFC_COUNT] = {
[CIP_SFC_32000] = 8,
[CIP_SFC_44100] = 8,
[CIP_SFC_48000] = 8,
[CIP_SFC_88200] = 16,
[CIP_SFC_96000] = 16,
[CIP_SFC_176400] = 32,
[CIP_SFC_192000] = 32,
};
EXPORT_SYMBOL(amdtp_syt_intervals);
const unsigned int amdtp_rate_table[CIP_SFC_COUNT] = {
[CIP_SFC_32000] = 32000,
[CIP_SFC_44100] = 44100,
[CIP_SFC_48000] = 48000,
[CIP_SFC_88200] = 88200,
[CIP_SFC_96000] = 96000,
[CIP_SFC_176400] = 176400,
[CIP_SFC_192000] = 192000,
};
EXPORT_SYMBOL(amdtp_rate_table);
/**
* amdtp_stream_add_pcm_hw_constraints - add hw constraints for PCM substream
* @s: the AMDTP stream, which must be initialized.
* @runtime: the PCM substream runtime
*/
int amdtp_stream_add_pcm_hw_constraints(struct amdtp_stream *s,
struct snd_pcm_runtime *runtime)
{
int err;
/*
* Currently firewire-lib processes 16 packets in one software
* interrupt callback. This equals to 2msec but actually the
* interval of the interrupts has a jitter.
* Additionally, even if adding a constraint to fit period size to
* 2msec, actual calculated frames per period doesn't equal to 2msec,
* depending on sampling rate.
* Anyway, the interval to call snd_pcm_period_elapsed() cannot 2msec.
* Here let us use 5msec for safe period interrupt.
*/
err = snd_pcm_hw_constraint_minmax(runtime,
SNDRV_PCM_HW_PARAM_PERIOD_TIME,
5000, UINT_MAX);
if (err < 0)
goto end;
/* Non-Blocking stream has no more constraints */
if (!(s->flags & CIP_BLOCKING))
goto end;
/*
* One AMDTP packet can include some frames. In blocking mode, the
* number equals to SYT_INTERVAL. So the number is 8, 16 or 32,
* depending on its sampling rate. For accurate period interrupt, it's
* preferrable to align period/buffer sizes to current SYT_INTERVAL.
*
* TODO: These constraints can be improved with proper rules.
* Currently apply LCM of SYT_INTERVALs.
*/
err = snd_pcm_hw_constraint_step(runtime, 0,
SNDRV_PCM_HW_PARAM_PERIOD_SIZE, 32);
if (err < 0)
goto end;
err = snd_pcm_hw_constraint_step(runtime, 0,
SNDRV_PCM_HW_PARAM_BUFFER_SIZE, 32);
end:
return err;
}
EXPORT_SYMBOL(amdtp_stream_add_pcm_hw_constraints);
/**
* amdtp_stream_set_parameters - set stream parameters
* @s: the AMDTP stream to configure
* @rate: the sample rate
* @data_block_quadlets: the size of a data block in quadlet unit
*
* The parameters must be set before the stream is started, and must not be
* changed while the stream is running.
*/
int amdtp_stream_set_parameters(struct amdtp_stream *s, unsigned int rate,
unsigned int data_block_quadlets)
{
unsigned int sfc;
for (sfc = 0; sfc < ARRAY_SIZE(amdtp_rate_table); ++sfc) {
if (amdtp_rate_table[sfc] == rate)
break;
}
if (sfc == ARRAY_SIZE(amdtp_rate_table))
return -EINVAL;
s->sfc = sfc;
s->data_block_quadlets = data_block_quadlets;
s->syt_interval = amdtp_syt_intervals[sfc];
/* default buffering in the device */
s->transfer_delay = TRANSFER_DELAY_TICKS - TICKS_PER_CYCLE;
if (s->flags & CIP_BLOCKING)
/* additional buffering needed to adjust for no-data packets */
s->transfer_delay += TICKS_PER_SECOND * s->syt_interval / rate;
return 0;
}
EXPORT_SYMBOL(amdtp_stream_set_parameters);
/**
* amdtp_stream_get_max_payload - get the stream's packet size
* @s: the AMDTP stream
*
* This function must not be called before the stream has been configured
* with amdtp_stream_set_parameters().
*/
unsigned int amdtp_stream_get_max_payload(struct amdtp_stream *s)
{
unsigned int multiplier = 1;
if (s->flags & CIP_JUMBO_PAYLOAD)
multiplier = 5;
return 8 + s->syt_interval * s->data_block_quadlets * 4 * multiplier;
}
EXPORT_SYMBOL(amdtp_stream_get_max_payload);
/**
* amdtp_stream_pcm_prepare - prepare PCM device for running
* @s: the AMDTP stream
*
* This function should be called from the PCM device's .prepare callback.
*/
void amdtp_stream_pcm_prepare(struct amdtp_stream *s)
{
tasklet_kill(&s->period_tasklet);
s->pcm_buffer_pointer = 0;
s->pcm_period_pointer = 0;
}
EXPORT_SYMBOL(amdtp_stream_pcm_prepare);
static unsigned int calculate_data_blocks(struct amdtp_stream *s,
unsigned int syt)
{
unsigned int phase, data_blocks;
/* Blocking mode. */
if (s->flags & CIP_BLOCKING) {
/* This module generate empty packet for 'no data'. */
if (syt == CIP_SYT_NO_INFO)
data_blocks = 0;
else
data_blocks = s->syt_interval;
/* Non-blocking mode. */
} else {
if (!cip_sfc_is_base_44100(s->sfc)) {
/* Sample_rate / 8000 is an integer, and precomputed. */
data_blocks = s->data_block_state;
} else {
phase = s->data_block_state;
/*
* This calculates the number of data blocks per packet so that
* 1) the overall rate is correct and exactly synchronized to
* the bus clock, and
* 2) packets with a rounded-up number of blocks occur as early
* as possible in the sequence (to prevent underruns of the
* device's buffer).
*/
if (s->sfc == CIP_SFC_44100)
/* 6 6 5 6 5 6 5 ... */
data_blocks = 5 + ((phase & 1) ^
(phase == 0 || phase >= 40));
else
/* 12 11 11 11 11 ... or 23 22 22 22 22 ... */
data_blocks = 11 * (s->sfc >> 1) + (phase == 0);
if (++phase >= (80 >> (s->sfc >> 1)))
phase = 0;
s->data_block_state = phase;
}
}
return data_blocks;
}
static unsigned int calculate_syt(struct amdtp_stream *s,
unsigned int cycle)
{
unsigned int syt_offset, phase, index, syt;
if (s->last_syt_offset < TICKS_PER_CYCLE) {
if (!cip_sfc_is_base_44100(s->sfc))
syt_offset = s->last_syt_offset + s->syt_offset_state;
else {
/*
* The time, in ticks, of the n'th SYT_INTERVAL sample is:
* n * SYT_INTERVAL * 24576000 / sample_rate
* Modulo TICKS_PER_CYCLE, the difference between successive
* elements is about 1386.23. Rounding the results of this
* formula to the SYT precision results in a sequence of
* differences that begins with:
* 1386 1386 1387 1386 1386 1386 1387 1386 1386 1386 1387 ...
* This code generates _exactly_ the same sequence.
*/
phase = s->syt_offset_state;
index = phase % 13;
syt_offset = s->last_syt_offset;
syt_offset += 1386 + ((index && !(index & 3)) ||
phase == 146);
if (++phase >= 147)
phase = 0;
s->syt_offset_state = phase;
}
} else
syt_offset = s->last_syt_offset - TICKS_PER_CYCLE;
s->last_syt_offset = syt_offset;
if (syt_offset < TICKS_PER_CYCLE) {
syt_offset += s->transfer_delay;
syt = (cycle + syt_offset / TICKS_PER_CYCLE) << 12;
syt += syt_offset % TICKS_PER_CYCLE;
return syt & CIP_SYT_MASK;
} else {
return CIP_SYT_NO_INFO;
}
}
static void update_pcm_pointers(struct amdtp_stream *s,
struct snd_pcm_substream *pcm,
unsigned int frames)
{
unsigned int ptr;
ptr = s->pcm_buffer_pointer + frames;
if (ptr >= pcm->runtime->buffer_size)
ptr -= pcm->runtime->buffer_size;
ACCESS_ONCE(s->pcm_buffer_pointer) = ptr;
s->pcm_period_pointer += frames;
if (s->pcm_period_pointer >= pcm->runtime->period_size) {
s->pcm_period_pointer -= pcm->runtime->period_size;
tasklet_hi_schedule(&s->period_tasklet);
}
}
static void pcm_period_tasklet(unsigned long data)
{
struct amdtp_stream *s = (void *)data;
struct snd_pcm_substream *pcm = ACCESS_ONCE(s->pcm);
if (pcm)
snd_pcm_period_elapsed(pcm);
}
static int queue_packet(struct amdtp_stream *s, unsigned int header_length,
unsigned int payload_length)
{
struct fw_iso_packet p = {0};
int err = 0;
if (IS_ERR(s->context))
goto end;
p.interrupt = IS_ALIGNED(s->packet_index + 1, INTERRUPT_INTERVAL);
p.tag = TAG_CIP;
p.header_length = header_length;
if (payload_length > 0)
p.payload_length = payload_length;
else
p.skip = true;
err = fw_iso_context_queue(s->context, &p, &s->buffer.iso_buffer,
s->buffer.packets[s->packet_index].offset);
if (err < 0) {
dev_err(&s->unit->device, "queueing error: %d\n", err);
goto end;
}
if (++s->packet_index >= QUEUE_LENGTH)
s->packet_index = 0;
end:
return err;
}
static inline int queue_out_packet(struct amdtp_stream *s,
unsigned int payload_length)
{
return queue_packet(s, OUT_PACKET_HEADER_SIZE, payload_length);
}
static inline int queue_in_packet(struct amdtp_stream *s)
{
return queue_packet(s, IN_PACKET_HEADER_SIZE,
amdtp_stream_get_max_payload(s));
}
static int handle_out_packet(struct amdtp_stream *s, unsigned int cycle,
unsigned int index)
{
__be32 *buffer;
unsigned int syt;
unsigned int data_blocks;
unsigned int payload_length;
unsigned int pcm_frames;
struct snd_pcm_substream *pcm;
buffer = s->buffer.packets[s->packet_index].buffer;
syt = calculate_syt(s, cycle);
data_blocks = calculate_data_blocks(s, syt);
pcm_frames = s->process_data_blocks(s, buffer + 2, data_blocks, &syt);
buffer[0] = cpu_to_be32(ACCESS_ONCE(s->source_node_id_field) |
(s->data_block_quadlets << CIP_DBS_SHIFT) |
s->data_block_counter);
buffer[1] = cpu_to_be32(CIP_EOH |
((s->fmt << CIP_FMT_SHIFT) & CIP_FMT_MASK) |
((s->fdf << CIP_FDF_SHIFT) & CIP_FDF_MASK) |
(syt & CIP_SYT_MASK));
s->data_block_counter = (s->data_block_counter + data_blocks) & 0xff;
payload_length = 8 + data_blocks * 4 * s->data_block_quadlets;
trace_out_packet(s, cycle, buffer, payload_length, index);
if (queue_out_packet(s, payload_length) < 0)
return -EIO;
pcm = ACCESS_ONCE(s->pcm);
if (pcm && pcm_frames > 0)
update_pcm_pointers(s, pcm, pcm_frames);
/* No need to return the number of handled data blocks. */
return 0;
}
static int handle_in_packet(struct amdtp_stream *s,
unsigned int payload_quadlets, unsigned int cycle,
unsigned int index)
{
__be32 *buffer;
u32 cip_header[2];
unsigned int fmt, fdf, syt;
unsigned int data_block_quadlets, data_block_counter, dbc_interval;
unsigned int data_blocks;
struct snd_pcm_substream *pcm;
unsigned int pcm_frames;
bool lost;
buffer = s->buffer.packets[s->packet_index].buffer;
cip_header[0] = be32_to_cpu(buffer[0]);
cip_header[1] = be32_to_cpu(buffer[1]);
trace_in_packet(s, cycle, cip_header, payload_quadlets, index);
/*
* This module supports 'Two-quadlet CIP header with SYT field'.
* For convenience, also check FMT field is AM824 or not.
*/
if (((cip_header[0] & CIP_EOH_MASK) == CIP_EOH) ||
((cip_header[1] & CIP_EOH_MASK) != CIP_EOH)) {
dev_info_ratelimited(&s->unit->device,
"Invalid CIP header for AMDTP: %08X:%08X\n",
cip_header[0], cip_header[1]);
data_blocks = 0;
pcm_frames = 0;
goto end;
}
/* Check valid protocol or not. */
fmt = (cip_header[1] & CIP_FMT_MASK) >> CIP_FMT_SHIFT;
if (fmt != s->fmt) {
dev_info_ratelimited(&s->unit->device,
"Detect unexpected protocol: %08x %08x\n",
cip_header[0], cip_header[1]);
data_blocks = 0;
pcm_frames = 0;
goto end;
}
/* Calculate data blocks */
fdf = (cip_header[1] & CIP_FDF_MASK) >> CIP_FDF_SHIFT;
if (payload_quadlets < 3 ||
(fmt == CIP_FMT_AM && fdf == AMDTP_FDF_NO_DATA)) {
data_blocks = 0;
} else {
data_block_quadlets =
(cip_header[0] & CIP_DBS_MASK) >> CIP_DBS_SHIFT;
/* avoid division by zero */
if (data_block_quadlets == 0) {
dev_err(&s->unit->device,
"Detect invalid value in dbs field: %08X\n",
cip_header[0]);
return -EPROTO;
}
if (s->flags & CIP_WRONG_DBS)
data_block_quadlets = s->data_block_quadlets;
data_blocks = (payload_quadlets - 2) / data_block_quadlets;
}
/* Check data block counter continuity */
data_block_counter = cip_header[0] & CIP_DBC_MASK;
if (data_blocks == 0 && (s->flags & CIP_EMPTY_HAS_WRONG_DBC) &&
s->data_block_counter != UINT_MAX)
data_block_counter = s->data_block_counter;
if (((s->flags & CIP_SKIP_DBC_ZERO_CHECK) &&
data_block_counter == s->tx_first_dbc) ||
s->data_block_counter == UINT_MAX) {
lost = false;
} else if (!(s->flags & CIP_DBC_IS_END_EVENT)) {
lost = data_block_counter != s->data_block_counter;
} else {
if (data_blocks > 0 && s->tx_dbc_interval > 0)
dbc_interval = s->tx_dbc_interval;
else
dbc_interval = data_blocks;
lost = data_block_counter !=
((s->data_block_counter + dbc_interval) & 0xff);
}
if (lost) {
dev_err(&s->unit->device,
"Detect discontinuity of CIP: %02X %02X\n",
s->data_block_counter, data_block_counter);
return -EIO;
}
syt = be32_to_cpu(buffer[1]) & CIP_SYT_MASK;
pcm_frames = s->process_data_blocks(s, buffer + 2, data_blocks, &syt);
if (s->flags & CIP_DBC_IS_END_EVENT)
s->data_block_counter = data_block_counter;
else
s->data_block_counter =
(data_block_counter + data_blocks) & 0xff;
end:
if (queue_in_packet(s) < 0)
return -EIO;
pcm = ACCESS_ONCE(s->pcm);
if (pcm && pcm_frames > 0)
update_pcm_pointers(s, pcm, pcm_frames);
return 0;
}
/*
* In CYCLE_TIMER register of IEEE 1394, 7 bits are used to represent second. On
* the other hand, in DMA descriptors of 1394 OHCI, 3 bits are used to represent
* it. Thus, via Linux firewire subsystem, we can get the 3 bits for second.
*/
static inline u32 compute_cycle_count(u32 tstamp)
{
return (((tstamp >> 13) & 0x07) * 8000) + (tstamp & 0x1fff);
}
static inline u32 increment_cycle_count(u32 cycle, unsigned int addend)
{
cycle += addend;
if (cycle >= 8 * CYCLES_PER_SECOND)
cycle -= 8 * CYCLES_PER_SECOND;
return cycle;
}
static inline u32 decrement_cycle_count(u32 cycle, unsigned int subtrahend)
{
if (cycle < subtrahend)
cycle += 8 * CYCLES_PER_SECOND;
return cycle - subtrahend;
}
static void out_stream_callback(struct fw_iso_context *context, u32 tstamp,
size_t header_length, void *header,
void *private_data)
{
struct amdtp_stream *s = private_data;
unsigned int i, packets = header_length / 4;
u32 cycle;
if (s->packet_index < 0)
return;
cycle = compute_cycle_count(tstamp);
/* Align to actual cycle count for the last packet. */
cycle = increment_cycle_count(cycle, QUEUE_LENGTH - packets);
for (i = 0; i < packets; ++i) {
cycle = increment_cycle_count(cycle, 1);
if (handle_out_packet(s, cycle, i) < 0) {
s->packet_index = -1;
amdtp_stream_pcm_abort(s);
return;
}
}
fw_iso_context_queue_flush(s->context);
}
static void in_stream_callback(struct fw_iso_context *context, u32 tstamp,
size_t header_length, void *header,
void *private_data)
{
struct amdtp_stream *s = private_data;
unsigned int i, packets;
unsigned int payload_quadlets, max_payload_quadlets;
__be32 *headers = header;
u32 cycle;
if (s->packet_index < 0)
return;
/* The number of packets in buffer */
packets = header_length / IN_PACKET_HEADER_SIZE;
cycle = compute_cycle_count(tstamp);
/* Align to actual cycle count for the last packet. */
cycle = decrement_cycle_count(cycle, packets);
/* For buffer-over-run prevention. */
max_payload_quadlets = amdtp_stream_get_max_payload(s) / 4;
for (i = 0; i < packets; i++) {
cycle = increment_cycle_count(cycle, 1);
/* The number of quadlets in this packet */
payload_quadlets =
(be32_to_cpu(headers[i]) >> ISO_DATA_LENGTH_SHIFT) / 4;
if (payload_quadlets > max_payload_quadlets) {
dev_err(&s->unit->device,
"Detect jumbo payload: %02x %02x\n",
payload_quadlets, max_payload_quadlets);
break;
}
if (handle_in_packet(s, payload_quadlets, cycle, i) < 0)
break;
}
/* Queueing error or detecting invalid payload. */
if (i < packets) {
s->packet_index = -1;
amdtp_stream_pcm_abort(s);
return;
}
fw_iso_context_queue_flush(s->context);
}
/* this is executed one time */
static void amdtp_stream_first_callback(struct fw_iso_context *context,
u32 tstamp, size_t header_length,
void *header, void *private_data)
{
struct amdtp_stream *s = private_data;
/*
* For in-stream, first packet has come.
* For out-stream, prepared to transmit first packet
*/
s->callbacked = true;
wake_up(&s->callback_wait);
if (s->direction == AMDTP_IN_STREAM)
context->callback.sc = in_stream_callback;
else
context->callback.sc = out_stream_callback;
context->callback.sc(context, tstamp, header_length, header, s);
}
/**
* amdtp_stream_start - start transferring packets
* @s: the AMDTP stream to start
* @channel: the isochronous channel on the bus
* @speed: firewire speed code
*
* The stream cannot be started until it has been configured with
* amdtp_stream_set_parameters() and it must be started before any PCM or MIDI
* device can be started.
*/
int amdtp_stream_start(struct amdtp_stream *s, int channel, int speed)
{
static const struct {
unsigned int data_block;
unsigned int syt_offset;
} initial_state[] = {
[CIP_SFC_32000] = { 4, 3072 },
[CIP_SFC_48000] = { 6, 1024 },
[CIP_SFC_96000] = { 12, 1024 },
[CIP_SFC_192000] = { 24, 1024 },
[CIP_SFC_44100] = { 0, 67 },
[CIP_SFC_88200] = { 0, 67 },
[CIP_SFC_176400] = { 0, 67 },
};
unsigned int header_size;
enum dma_data_direction dir;
int type, tag, err;
mutex_lock(&s->mutex);
if (WARN_ON(amdtp_stream_running(s) ||
(s->data_block_quadlets < 1))) {
err = -EBADFD;
goto err_unlock;
}
if (s->direction == AMDTP_IN_STREAM)
s->data_block_counter = UINT_MAX;
else
s->data_block_counter = 0;
s->data_block_state = initial_state[s->sfc].data_block;
s->syt_offset_state = initial_state[s->sfc].syt_offset;
s->last_syt_offset = TICKS_PER_CYCLE;
/* initialize packet buffer */
if (s->direction == AMDTP_IN_STREAM) {
dir = DMA_FROM_DEVICE;
type = FW_ISO_CONTEXT_RECEIVE;
header_size = IN_PACKET_HEADER_SIZE;
} else {
dir = DMA_TO_DEVICE;
type = FW_ISO_CONTEXT_TRANSMIT;
header_size = OUT_PACKET_HEADER_SIZE;
}
err = iso_packets_buffer_init(&s->buffer, s->unit, QUEUE_LENGTH,
amdtp_stream_get_max_payload(s), dir);
if (err < 0)
goto err_unlock;
s->context = fw_iso_context_create(fw_parent_device(s->unit)->card,
type, channel, speed, header_size,
amdtp_stream_first_callback, s);
if (IS_ERR(s->context)) {
err = PTR_ERR(s->context);
if (err == -EBUSY)
dev_err(&s->unit->device,
"no free stream on this controller\n");
goto err_buffer;
}
amdtp_stream_update(s);
s->packet_index = 0;
do {
if (s->direction == AMDTP_IN_STREAM)
err = queue_in_packet(s);
else
err = queue_out_packet(s, 0);
if (err < 0)
goto err_context;
} while (s->packet_index > 0);
/* NOTE: TAG1 matches CIP. This just affects in stream. */
tag = FW_ISO_CONTEXT_MATCH_TAG1;
if (s->flags & CIP_EMPTY_WITH_TAG0)
tag |= FW_ISO_CONTEXT_MATCH_TAG0;
s->callbacked = false;
err = fw_iso_context_start(s->context, -1, 0, tag);
if (err < 0)
goto err_context;
mutex_unlock(&s->mutex);
return 0;
err_context:
fw_iso_context_destroy(s->context);
s->context = ERR_PTR(-1);
err_buffer:
iso_packets_buffer_destroy(&s->buffer, s->unit);
err_unlock:
mutex_unlock(&s->mutex);
return err;
}
EXPORT_SYMBOL(amdtp_stream_start);
/**
* amdtp_stream_pcm_pointer - get the PCM buffer position
* @s: the AMDTP stream that transports the PCM data
*
* Returns the current buffer position, in frames.
*/
unsigned long amdtp_stream_pcm_pointer(struct amdtp_stream *s)
{
/*
* This function is called in software IRQ context of period_tasklet or
* process context.
*
* When the software IRQ context was scheduled by software IRQ context
* of IR/IT contexts, queued packets were already handled. Therefore,
* no need to flush the queue in buffer anymore.
*
* When the process context reach here, some packets will be already
* queued in the buffer. These packets should be handled immediately
* to keep better granularity of PCM pointer.
*
* Later, the process context will sometimes schedules software IRQ
* context of the period_tasklet. Then, no need to flush the queue by
* the same reason as described for IR/IT contexts.
*/
if (!in_interrupt() && amdtp_stream_running(s))
fw_iso_context_flush_completions(s->context);
return ACCESS_ONCE(s->pcm_buffer_pointer);
}
EXPORT_SYMBOL(amdtp_stream_pcm_pointer);
/**
* amdtp_stream_update - update the stream after a bus reset
* @s: the AMDTP stream
*/
void amdtp_stream_update(struct amdtp_stream *s)
{
/* Precomputing. */
ACCESS_ONCE(s->source_node_id_field) =
(fw_parent_device(s->unit)->card->node_id << CIP_SID_SHIFT) &
CIP_SID_MASK;
}
EXPORT_SYMBOL(amdtp_stream_update);
/**
* amdtp_stream_stop - stop sending packets
* @s: the AMDTP stream to stop
*
* All PCM and MIDI devices of the stream must be stopped before the stream
* itself can be stopped.
*/
void amdtp_stream_stop(struct amdtp_stream *s)
{
mutex_lock(&s->mutex);
if (!amdtp_stream_running(s)) {
mutex_unlock(&s->mutex);
return;
}
tasklet_kill(&s->period_tasklet);
fw_iso_context_stop(s->context);
fw_iso_context_destroy(s->context);
s->context = ERR_PTR(-1);
iso_packets_buffer_destroy(&s->buffer, s->unit);
s->callbacked = false;
mutex_unlock(&s->mutex);
}
EXPORT_SYMBOL(amdtp_stream_stop);
/**
* amdtp_stream_pcm_abort - abort the running PCM device
* @s: the AMDTP stream about to be stopped
*
* If the isochronous stream needs to be stopped asynchronously, call this
* function first to stop the PCM device.
*/
void amdtp_stream_pcm_abort(struct amdtp_stream *s)
{
struct snd_pcm_substream *pcm;
pcm = ACCESS_ONCE(s->pcm);
if (pcm)
snd_pcm_stop_xrun(pcm);
}
EXPORT_SYMBOL(amdtp_stream_pcm_abort);