linux-stable/sound/firewire/amdtp-stream.c
Takashi Sakamoto acfedcbe1c ALSA: firewire-lib: postpone to start IR context
Some devices have a quirk to postpone transmission of isoc packet for
several dozen or hundred isoc cycles since configured to transmit.
Furthermore, some devices have a quirk to transmit isoc packet with
discontinued data of its header.

In 1394 OHCI specification, software allows to start isoc context with
certain isoc cycle. Linux firewire subsystem has kernel API to use it
as well.

This commit uses the functionality of 1394 OHCI controller to handle
the quirks. At present, this feature is convenient to ALSA bebob and
fireface driver. As a result, some devices can be safely handled, as
long as I know:
 - MAudio FireWire solo
 - MAudio ProFire Lightbridge
 - MAudio FireWire 410
 - Roland FA-66

Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Link: https://lore.kernel.org/r/20191018061911.24909-7-o-takashi@sakamocchi.jp
Signed-off-by: Takashi Iwai <tiwai@suse.de>
2019-10-19 09:18:27 +02:00

1470 lines
40 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
* 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>
*/
#include <linux/device.h>
#include <linux/err.h>
#include <linux/firewire.h>
#include <linux/firewire-constants.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_NO_CIP_HEADER 0
#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_SPH_MASK 0x00000400
#define CIP_SPH_SHIFT 10
#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
// For iso header, tstamp and 2 CIP header.
#define IR_CTX_HEADER_SIZE_CIP 16
// For iso header and tstamp.
#define IR_CTX_HEADER_SIZE_NO_CIP 8
#define HEADER_TSTAMP_MASK 0x0000ffff
#define IT_PKT_HEADER_SIZE_CIP 8 // For 2 CIP header.
#define IT_PKT_HEADER_SIZE_NO_CIP 0 // Nothing.
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_ctx_payloads: callback handler to process payloads of isoc context
* @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_ctx_payloads_t process_ctx_payloads,
unsigned int protocol_size)
{
if (process_ctx_payloads == 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_ctx_payloads = process_ctx_payloads;
if (dir == AMDTP_OUT_STREAM)
s->ctx_data.rx.syt_override = -1;
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);
static int apply_constraint_to_size(struct snd_pcm_hw_params *params,
struct snd_pcm_hw_rule *rule)
{
struct snd_interval *s = hw_param_interval(params, rule->var);
const struct snd_interval *r =
hw_param_interval_c(params, SNDRV_PCM_HW_PARAM_RATE);
struct snd_interval t = {0};
unsigned int step = 0;
int i;
for (i = 0; i < CIP_SFC_COUNT; ++i) {
if (snd_interval_test(r, amdtp_rate_table[i]))
step = max(step, amdtp_syt_intervals[i]);
}
t.min = roundup(s->min, step);
t.max = rounddown(s->max, step);
t.integer = 1;
return snd_interval_refine(s, &t);
}
/**
* 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)
{
struct snd_pcm_hardware *hw = &runtime->hw;
unsigned int ctx_header_size;
unsigned int maximum_usec_per_period;
int err;
hw->info = SNDRV_PCM_INFO_BATCH |
SNDRV_PCM_INFO_BLOCK_TRANSFER |
SNDRV_PCM_INFO_INTERLEAVED |
SNDRV_PCM_INFO_JOINT_DUPLEX |
SNDRV_PCM_INFO_MMAP |
SNDRV_PCM_INFO_MMAP_VALID;
/* SNDRV_PCM_INFO_BATCH */
hw->periods_min = 2;
hw->periods_max = UINT_MAX;
/* bytes for a frame */
hw->period_bytes_min = 4 * hw->channels_max;
/* Just to prevent from allocating much pages. */
hw->period_bytes_max = hw->period_bytes_min * 2048;
hw->buffer_bytes_max = hw->period_bytes_max * hw->periods_min;
// Linux driver for 1394 OHCI controller voluntarily flushes isoc
// context when total size of accumulated context header reaches
// PAGE_SIZE. This kicks tasklet for the isoc context and brings
// callback in the middle of scheduled interrupts.
// Although AMDTP streams in the same domain use the same events per
// IRQ, use the largest size of context header between IT/IR contexts.
// Here, use the value of context header in IR context is for both
// contexts.
if (!(s->flags & CIP_NO_HEADER))
ctx_header_size = IR_CTX_HEADER_SIZE_CIP;
else
ctx_header_size = IR_CTX_HEADER_SIZE_NO_CIP;
maximum_usec_per_period = USEC_PER_SEC * PAGE_SIZE /
CYCLES_PER_SECOND / ctx_header_size;
// In IEC 61883-6, one isoc packet can transfer events up to the value
// of syt interval. This comes from the interval of isoc cycle. As 1394
// OHCI controller can generate hardware IRQ per isoc packet, the
// interval is 125 usec.
// However, there are two ways of transmission in IEC 61883-6; blocking
// and non-blocking modes. In blocking mode, the sequence of isoc packet
// includes 'empty' or 'NODATA' packets which include no event. In
// non-blocking mode, the number of events per packet is variable up to
// the syt interval.
// Due to the above protocol design, the minimum PCM frames per
// interrupt should be double of the value of syt interval, thus it is
// 250 usec.
err = snd_pcm_hw_constraint_minmax(runtime,
SNDRV_PCM_HW_PARAM_PERIOD_TIME,
250, maximum_usec_per_period);
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.
*/
err = snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_PERIOD_SIZE,
apply_constraint_to_size, NULL,
SNDRV_PCM_HW_PARAM_PERIOD_SIZE,
SNDRV_PCM_HW_PARAM_RATE, -1);
if (err < 0)
goto end;
err = snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_BUFFER_SIZE,
apply_constraint_to_size, NULL,
SNDRV_PCM_HW_PARAM_BUFFER_SIZE,
SNDRV_PCM_HW_PARAM_RATE, -1);
if (err < 0)
goto end;
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.
if (s->direction == AMDTP_OUT_STREAM) {
s->ctx_data.rx.transfer_delay =
TRANSFER_DELAY_TICKS - TICKS_PER_CYCLE;
if (s->flags & CIP_BLOCKING) {
// additional buffering needed to adjust for no-data
// packets.
s->ctx_data.rx.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;
unsigned int cip_header_size = 0;
if (s->flags & CIP_JUMBO_PAYLOAD)
multiplier = 5;
if (!(s->flags & CIP_NO_HEADER))
cip_header_size = sizeof(__be32) * 2;
return cip_header_size +
s->syt_interval * s->data_block_quadlets * sizeof(__be32) * 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->ctx_data.rx.data_block_state;
} else {
phase = s->ctx_data.rx.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->ctx_data.rx.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->ctx_data.rx.last_syt_offset < TICKS_PER_CYCLE) {
if (!cip_sfc_is_base_44100(s->sfc))
syt_offset = s->ctx_data.rx.last_syt_offset +
s->ctx_data.rx.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->ctx_data.rx.syt_offset_state;
index = phase % 13;
syt_offset = s->ctx_data.rx.last_syt_offset;
syt_offset += 1386 + ((index && !(index & 3)) ||
phase == 146);
if (++phase >= 147)
phase = 0;
s->ctx_data.rx.syt_offset_state = phase;
}
} else
syt_offset = s->ctx_data.rx.last_syt_offset - TICKS_PER_CYCLE;
s->ctx_data.rx.last_syt_offset = syt_offset;
if (syt_offset < TICKS_PER_CYCLE) {
syt_offset += s->ctx_data.rx.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;
WRITE_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 = READ_ONCE(s->pcm);
if (pcm)
snd_pcm_period_elapsed(pcm);
}
static int queue_packet(struct amdtp_stream *s, struct fw_iso_packet *params,
bool sched_irq)
{
int err;
params->interrupt = sched_irq;
params->tag = s->tag;
params->sy = 0;
err = fw_iso_context_queue(s->context, params, &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 >= s->queue_size)
s->packet_index = 0;
end:
return err;
}
static inline int queue_out_packet(struct amdtp_stream *s,
struct fw_iso_packet *params, bool sched_irq)
{
params->skip =
!!(params->header_length == 0 && params->payload_length == 0);
return queue_packet(s, params, sched_irq);
}
static inline int queue_in_packet(struct amdtp_stream *s,
struct fw_iso_packet *params)
{
// Queue one packet for IR context.
params->header_length = s->ctx_data.tx.ctx_header_size;
params->payload_length = s->ctx_data.tx.max_ctx_payload_length;
params->skip = false;
return queue_packet(s, params, false);
}
static void generate_cip_header(struct amdtp_stream *s, __be32 cip_header[2],
unsigned int data_block_counter, unsigned int syt)
{
cip_header[0] = cpu_to_be32(READ_ONCE(s->source_node_id_field) |
(s->data_block_quadlets << CIP_DBS_SHIFT) |
((s->sph << CIP_SPH_SHIFT) & CIP_SPH_MASK) |
data_block_counter);
cip_header[1] = cpu_to_be32(CIP_EOH |
((s->fmt << CIP_FMT_SHIFT) & CIP_FMT_MASK) |
((s->ctx_data.rx.fdf << CIP_FDF_SHIFT) & CIP_FDF_MASK) |
(syt & CIP_SYT_MASK));
}
static void build_it_pkt_header(struct amdtp_stream *s, unsigned int cycle,
struct fw_iso_packet *params,
unsigned int data_blocks,
unsigned int data_block_counter,
unsigned int syt, unsigned int index)
{
unsigned int payload_length;
__be32 *cip_header;
payload_length = data_blocks * sizeof(__be32) * s->data_block_quadlets;
params->payload_length = payload_length;
if (!(s->flags & CIP_NO_HEADER)) {
cip_header = (__be32 *)params->header;
generate_cip_header(s, cip_header, data_block_counter, syt);
params->header_length = 2 * sizeof(__be32);
payload_length += params->header_length;
} else {
cip_header = NULL;
}
trace_amdtp_packet(s, cycle, cip_header, payload_length, data_blocks,
data_block_counter, index);
}
static int check_cip_header(struct amdtp_stream *s, const __be32 *buf,
unsigned int payload_length,
unsigned int *data_blocks,
unsigned int *data_block_counter, unsigned int *syt)
{
u32 cip_header[2];
unsigned int sph;
unsigned int fmt;
unsigned int fdf;
unsigned int dbc;
bool lost;
cip_header[0] = be32_to_cpu(buf[0]);
cip_header[1] = be32_to_cpu(buf[1]);
/*
* 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)) &&
(!(s->flags & CIP_HEADER_WITHOUT_EOH))) {
dev_info_ratelimited(&s->unit->device,
"Invalid CIP header for AMDTP: %08X:%08X\n",
cip_header[0], cip_header[1]);
return -EAGAIN;
}
/* Check valid protocol or not. */
sph = (cip_header[0] & CIP_SPH_MASK) >> CIP_SPH_SHIFT;
fmt = (cip_header[1] & CIP_FMT_MASK) >> CIP_FMT_SHIFT;
if (sph != s->sph || fmt != s->fmt) {
dev_info_ratelimited(&s->unit->device,
"Detect unexpected protocol: %08x %08x\n",
cip_header[0], cip_header[1]);
return -EAGAIN;
}
/* Calculate data blocks */
fdf = (cip_header[1] & CIP_FDF_MASK) >> CIP_FDF_SHIFT;
if (payload_length < sizeof(__be32) * 2 ||
(fmt == CIP_FMT_AM && fdf == AMDTP_FDF_NO_DATA)) {
*data_blocks = 0;
} else {
unsigned int 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_length / sizeof(__be32) - 2) /
data_block_quadlets;
}
/* Check data block counter continuity */
dbc = cip_header[0] & CIP_DBC_MASK;
if (*data_blocks == 0 && (s->flags & CIP_EMPTY_HAS_WRONG_DBC) &&
*data_block_counter != UINT_MAX)
dbc = *data_block_counter;
if ((dbc == 0x00 && (s->flags & CIP_SKIP_DBC_ZERO_CHECK)) ||
*data_block_counter == UINT_MAX) {
lost = false;
} else if (!(s->flags & CIP_DBC_IS_END_EVENT)) {
lost = dbc != *data_block_counter;
} else {
unsigned int dbc_interval;
if (*data_blocks > 0 && s->ctx_data.tx.dbc_interval > 0)
dbc_interval = s->ctx_data.tx.dbc_interval;
else
dbc_interval = *data_blocks;
lost = dbc != ((*data_block_counter + dbc_interval) & 0xff);
}
if (lost) {
dev_err(&s->unit->device,
"Detect discontinuity of CIP: %02X %02X\n",
*data_block_counter, dbc);
return -EIO;
}
*data_block_counter = dbc;
*syt = cip_header[1] & CIP_SYT_MASK;
return 0;
}
static int parse_ir_ctx_header(struct amdtp_stream *s, unsigned int cycle,
const __be32 *ctx_header,
unsigned int *payload_length,
unsigned int *data_blocks,
unsigned int *data_block_counter,
unsigned int *syt, unsigned int index)
{
const __be32 *cip_header;
int err;
*payload_length = be32_to_cpu(ctx_header[0]) >> ISO_DATA_LENGTH_SHIFT;
if (*payload_length > s->ctx_data.tx.ctx_header_size +
s->ctx_data.tx.max_ctx_payload_length) {
dev_err(&s->unit->device,
"Detect jumbo payload: %04x %04x\n",
*payload_length, s->ctx_data.tx.max_ctx_payload_length);
return -EIO;
}
if (!(s->flags & CIP_NO_HEADER)) {
cip_header = ctx_header + 2;
err = check_cip_header(s, cip_header, *payload_length,
data_blocks, data_block_counter, syt);
if (err < 0)
return err;
} else {
cip_header = NULL;
err = 0;
*data_blocks = *payload_length / sizeof(__be32) /
s->data_block_quadlets;
*syt = 0;
if (*data_block_counter == UINT_MAX)
*data_block_counter = 0;
}
trace_amdtp_packet(s, cycle, cip_header, *payload_length, *data_blocks,
*data_block_counter, index);
return err;
}
// 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(__be32 ctx_header_tstamp)
{
u32 tstamp = be32_to_cpu(ctx_header_tstamp) & HEADER_TSTAMP_MASK;
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;
}
// Align to actual cycle count for the packet which is going to be scheduled.
// This module queued the same number of isochronous cycle as the size of queue
// to kip isochronous cycle, therefore it's OK to just increment the cycle by
// the size of queue for scheduled cycle.
static inline u32 compute_it_cycle(const __be32 ctx_header_tstamp,
unsigned int queue_size)
{
u32 cycle = compute_cycle_count(ctx_header_tstamp);
return increment_cycle_count(cycle, queue_size);
}
static int generate_device_pkt_descs(struct amdtp_stream *s,
struct pkt_desc *descs,
const __be32 *ctx_header,
unsigned int packets)
{
unsigned int dbc = s->data_block_counter;
int i;
int err;
for (i = 0; i < packets; ++i) {
struct pkt_desc *desc = descs + i;
unsigned int index = (s->packet_index + i) % s->queue_size;
unsigned int cycle;
unsigned int payload_length;
unsigned int data_blocks;
unsigned int syt;
cycle = compute_cycle_count(ctx_header[1]);
err = parse_ir_ctx_header(s, cycle, ctx_header, &payload_length,
&data_blocks, &dbc, &syt, i);
if (err < 0)
return err;
desc->cycle = cycle;
desc->syt = syt;
desc->data_blocks = data_blocks;
desc->data_block_counter = dbc;
desc->ctx_payload = s->buffer.packets[index].buffer;
if (!(s->flags & CIP_DBC_IS_END_EVENT))
dbc = (dbc + desc->data_blocks) & 0xff;
ctx_header +=
s->ctx_data.tx.ctx_header_size / sizeof(*ctx_header);
}
s->data_block_counter = dbc;
return 0;
}
static void generate_ideal_pkt_descs(struct amdtp_stream *s,
struct pkt_desc *descs,
const __be32 *ctx_header,
unsigned int packets)
{
unsigned int dbc = s->data_block_counter;
int i;
for (i = 0; i < packets; ++i) {
struct pkt_desc *desc = descs + i;
unsigned int index = (s->packet_index + i) % s->queue_size;
desc->cycle = compute_it_cycle(*ctx_header, s->queue_size);
desc->syt = calculate_syt(s, desc->cycle);
desc->data_blocks = calculate_data_blocks(s, desc->syt);
if (s->flags & CIP_DBC_IS_END_EVENT)
dbc = (dbc + desc->data_blocks) & 0xff;
desc->data_block_counter = dbc;
if (!(s->flags & CIP_DBC_IS_END_EVENT))
dbc = (dbc + desc->data_blocks) & 0xff;
desc->ctx_payload = s->buffer.packets[index].buffer;
++ctx_header;
}
s->data_block_counter = dbc;
}
static inline void cancel_stream(struct amdtp_stream *s)
{
s->packet_index = -1;
if (in_interrupt())
amdtp_stream_pcm_abort(s);
WRITE_ONCE(s->pcm_buffer_pointer, SNDRV_PCM_POS_XRUN);
}
static void process_ctx_payloads(struct amdtp_stream *s,
const struct pkt_desc *descs,
unsigned int packets)
{
struct snd_pcm_substream *pcm;
unsigned int pcm_frames;
pcm = READ_ONCE(s->pcm);
pcm_frames = s->process_ctx_payloads(s, descs, packets, pcm);
if (pcm)
update_pcm_pointers(s, pcm, pcm_frames);
}
static void amdtp_stream_master_callback(struct fw_iso_context *context,
u32 tstamp, size_t header_length,
void *header, void *private_data);
static void amdtp_stream_master_first_callback(struct fw_iso_context *context,
u32 tstamp, size_t header_length,
void *header, void *private_data);
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;
const __be32 *ctx_header = header;
unsigned int events_per_period = s->ctx_data.rx.events_per_period;
unsigned int event_count = s->ctx_data.rx.event_count;
unsigned int packets;
bool is_irq_target;
int i;
if (s->packet_index < 0)
return;
// Calculate the number of packets in buffer and check XRUN.
packets = header_length / sizeof(*ctx_header);
generate_ideal_pkt_descs(s, s->pkt_descs, ctx_header, packets);
process_ctx_payloads(s, s->pkt_descs, packets);
is_irq_target =
!!(context->callback.sc == amdtp_stream_master_callback ||
context->callback.sc == amdtp_stream_master_first_callback);
for (i = 0; i < packets; ++i) {
const struct pkt_desc *desc = s->pkt_descs + i;
unsigned int syt;
struct {
struct fw_iso_packet params;
__be32 header[IT_PKT_HEADER_SIZE_CIP / sizeof(__be32)];
} template = { {0}, {0} };
bool sched_irq = false;
if (s->ctx_data.rx.syt_override < 0)
syt = desc->syt;
else
syt = s->ctx_data.rx.syt_override;
build_it_pkt_header(s, desc->cycle, &template.params,
desc->data_blocks, desc->data_block_counter,
syt, i);
if (is_irq_target) {
event_count += desc->data_blocks;
if (event_count >= events_per_period) {
event_count -= events_per_period;
sched_irq = true;
}
}
if (queue_out_packet(s, &template.params, sched_irq) < 0) {
cancel_stream(s);
return;
}
}
s->ctx_data.rx.event_count = event_count;
}
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;
__be32 *ctx_header = header;
unsigned int packets;
int i;
int err;
if (s->packet_index < 0)
return;
// Calculate the number of packets in buffer and check XRUN.
packets = header_length / s->ctx_data.tx.ctx_header_size;
err = generate_device_pkt_descs(s, s->pkt_descs, ctx_header, packets);
if (err < 0) {
if (err != -EAGAIN) {
cancel_stream(s);
return;
}
} else {
process_ctx_payloads(s, s->pkt_descs, packets);
}
for (i = 0; i < packets; ++i) {
struct fw_iso_packet params = {0};
if (queue_in_packet(s, &params) < 0) {
cancel_stream(s);
return;
}
}
}
static void amdtp_stream_master_callback(struct fw_iso_context *context,
u32 tstamp, size_t header_length,
void *header, void *private_data)
{
struct amdtp_domain *d = private_data;
struct amdtp_stream *irq_target = d->irq_target;
struct amdtp_stream *s;
out_stream_callback(context, tstamp, header_length, header, irq_target);
if (amdtp_streaming_error(irq_target))
goto error;
list_for_each_entry(s, &d->streams, list) {
if (s != irq_target && amdtp_stream_running(s)) {
fw_iso_context_flush_completions(s->context);
if (amdtp_streaming_error(s))
goto error;
}
}
return;
error:
if (amdtp_stream_running(irq_target))
cancel_stream(irq_target);
list_for_each_entry(s, &d->streams, list) {
if (amdtp_stream_running(s))
cancel_stream(s);
}
}
// 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;
const __be32 *ctx_header = header;
u32 cycle;
/*
* 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) {
cycle = compute_cycle_count(ctx_header[1]);
context->callback.sc = in_stream_callback;
} else {
cycle = compute_it_cycle(*ctx_header, s->queue_size);
context->callback.sc = out_stream_callback;
}
s->start_cycle = cycle;
context->callback.sc(context, tstamp, header_length, header, s);
}
static void amdtp_stream_master_first_callback(struct fw_iso_context *context,
u32 tstamp, size_t header_length,
void *header, void *private_data)
{
struct amdtp_domain *d = private_data;
struct amdtp_stream *s = d->irq_target;
const __be32 *ctx_header = header;
s->callbacked = true;
wake_up(&s->callback_wait);
s->start_cycle = compute_it_cycle(*ctx_header, s->queue_size);
context->callback.sc = amdtp_stream_master_callback;
context->callback.sc(context, tstamp, header_length, header, d);
}
/**
* amdtp_stream_start - start transferring packets
* @s: the AMDTP stream to start
* @channel: the isochronous channel on the bus
* @speed: firewire speed code
* @d: the AMDTP domain to which the AMDTP stream belongs
* @is_irq_target: whether isoc context for the AMDTP stream is used to generate
* hardware IRQ.
* @start_cycle: the isochronous cycle to start the context. Start immediately
* if negative value is given.
*
* 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.
*/
static int amdtp_stream_start(struct amdtp_stream *s, int channel, int speed,
struct amdtp_domain *d, bool is_irq_target,
int start_cycle)
{
static const struct {
unsigned int data_block;
unsigned int syt_offset;
} *entry, 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 events_per_buffer = d->events_per_buffer;
unsigned int events_per_period = d->events_per_period;
unsigned int idle_irq_interval;
unsigned int ctx_header_size;
unsigned int max_ctx_payload_size;
enum dma_data_direction dir;
int type, tag, err;
fw_iso_callback_t ctx_cb;
void *ctx_data;
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) {
// NOTE: IT context should be used for constant IRQ.
if (is_irq_target) {
err = -EINVAL;
goto err_unlock;
}
s->data_block_counter = UINT_MAX;
} else {
entry = &initial_state[s->sfc];
s->data_block_counter = 0;
s->ctx_data.rx.data_block_state = entry->data_block;
s->ctx_data.rx.syt_offset_state = entry->syt_offset;
s->ctx_data.rx.last_syt_offset = TICKS_PER_CYCLE;
}
/* initialize packet buffer */
if (s->direction == AMDTP_IN_STREAM) {
dir = DMA_FROM_DEVICE;
type = FW_ISO_CONTEXT_RECEIVE;
if (!(s->flags & CIP_NO_HEADER))
ctx_header_size = IR_CTX_HEADER_SIZE_CIP;
else
ctx_header_size = IR_CTX_HEADER_SIZE_NO_CIP;
max_ctx_payload_size = amdtp_stream_get_max_payload(s) -
ctx_header_size;
} else {
dir = DMA_TO_DEVICE;
type = FW_ISO_CONTEXT_TRANSMIT;
ctx_header_size = 0; // No effect for IT context.
max_ctx_payload_size = amdtp_stream_get_max_payload(s);
if (!(s->flags & CIP_NO_HEADER))
max_ctx_payload_size -= IT_PKT_HEADER_SIZE_CIP;
}
// This is a case that AMDTP streams in domain run just for MIDI
// substream. Use the number of events equivalent to 10 msec as
// interval of hardware IRQ.
if (events_per_period == 0)
events_per_period = amdtp_rate_table[s->sfc] / 100;
if (events_per_buffer == 0)
events_per_buffer = events_per_period * 3;
idle_irq_interval = DIV_ROUND_UP(CYCLES_PER_SECOND * events_per_period,
amdtp_rate_table[s->sfc]);
s->queue_size = DIV_ROUND_UP(CYCLES_PER_SECOND * events_per_buffer,
amdtp_rate_table[s->sfc]);
err = iso_packets_buffer_init(&s->buffer, s->unit, s->queue_size,
max_ctx_payload_size, dir);
if (err < 0)
goto err_unlock;
if (is_irq_target) {
s->ctx_data.rx.events_per_period = events_per_period;
s->ctx_data.rx.event_count = 0;
ctx_cb = amdtp_stream_master_first_callback;
ctx_data = d;
} else {
ctx_cb = amdtp_stream_first_callback;
ctx_data = s;
}
s->context = fw_iso_context_create(fw_parent_device(s->unit)->card,
type, channel, speed, ctx_header_size,
ctx_cb, ctx_data);
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);
if (s->direction == AMDTP_IN_STREAM) {
s->ctx_data.tx.max_ctx_payload_length = max_ctx_payload_size;
s->ctx_data.tx.ctx_header_size = ctx_header_size;
}
if (s->flags & CIP_NO_HEADER)
s->tag = TAG_NO_CIP_HEADER;
else
s->tag = TAG_CIP;
s->pkt_descs = kcalloc(s->queue_size, sizeof(*s->pkt_descs),
GFP_KERNEL);
if (!s->pkt_descs) {
err = -ENOMEM;
goto err_context;
}
s->packet_index = 0;
do {
struct fw_iso_packet params;
if (s->direction == AMDTP_IN_STREAM) {
err = queue_in_packet(s, &params);
} else {
bool sched_irq = false;
params.header_length = 0;
params.payload_length = 0;
if (is_irq_target) {
sched_irq = !((s->packet_index + 1) %
idle_irq_interval);
}
err = queue_out_packet(s, &params, sched_irq);
}
if (err < 0)
goto err_pkt_descs;
} 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) || (s->flags & CIP_NO_HEADER))
tag |= FW_ISO_CONTEXT_MATCH_TAG0;
s->callbacked = false;
err = fw_iso_context_start(s->context, start_cycle, 0, tag);
if (err < 0)
goto err_pkt_descs;
mutex_unlock(&s->mutex);
return 0;
err_pkt_descs:
kfree(s->pkt_descs);
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;
}
/**
* amdtp_domain_stream_pcm_pointer - get the PCM buffer position
* @d: the AMDTP domain.
* @s: the AMDTP stream that transports the PCM data
*
* Returns the current buffer position, in frames.
*/
unsigned long amdtp_domain_stream_pcm_pointer(struct amdtp_domain *d,
struct amdtp_stream *s)
{
struct amdtp_stream *irq_target = d->irq_target;
if (irq_target && amdtp_stream_running(irq_target)) {
// 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 IT contexts, queued packets were already handled.
// Therefore, no need to flush the queue in buffer furthermore.
//
// 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 in the above
if (!in_interrupt()) {
// Queued packet should be processed without any kernel
// preemption to keep latency against bus cycle.
preempt_disable();
fw_iso_context_flush_completions(irq_target->context);
preempt_enable();
}
}
return READ_ONCE(s->pcm_buffer_pointer);
}
EXPORT_SYMBOL_GPL(amdtp_domain_stream_pcm_pointer);
/**
* amdtp_domain_stream_pcm_ack - acknowledge queued PCM frames
* @d: the AMDTP domain.
* @s: the AMDTP stream that transfers the PCM frames
*
* Returns zero always.
*/
int amdtp_domain_stream_pcm_ack(struct amdtp_domain *d, struct amdtp_stream *s)
{
struct amdtp_stream *irq_target = d->irq_target;
// Process isochronous packets for recent isochronous cycle to handle
// queued PCM frames.
if (irq_target && amdtp_stream_running(irq_target)) {
// Queued packet should be processed without any kernel
// preemption to keep latency against bus cycle.
preempt_disable();
fw_iso_context_flush_completions(irq_target->context);
preempt_enable();
}
return 0;
}
EXPORT_SYMBOL_GPL(amdtp_domain_stream_pcm_ack);
/**
* amdtp_stream_update - update the stream after a bus reset
* @s: the AMDTP stream
*/
void amdtp_stream_update(struct amdtp_stream *s)
{
/* Precomputing. */
WRITE_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.
*/
static 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);
kfree(s->pkt_descs);
s->callbacked = false;
mutex_unlock(&s->mutex);
}
/**
* 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 = READ_ONCE(s->pcm);
if (pcm)
snd_pcm_stop_xrun(pcm);
}
EXPORT_SYMBOL(amdtp_stream_pcm_abort);
/**
* amdtp_domain_init - initialize an AMDTP domain structure
* @d: the AMDTP domain to initialize.
*/
int amdtp_domain_init(struct amdtp_domain *d)
{
INIT_LIST_HEAD(&d->streams);
d->events_per_period = 0;
return 0;
}
EXPORT_SYMBOL_GPL(amdtp_domain_init);
/**
* amdtp_domain_destroy - destroy an AMDTP domain structure
* @d: the AMDTP domain to destroy.
*/
void amdtp_domain_destroy(struct amdtp_domain *d)
{
// At present nothing to do.
return;
}
EXPORT_SYMBOL_GPL(amdtp_domain_destroy);
/**
* amdtp_domain_add_stream - register isoc context into the domain.
* @d: the AMDTP domain.
* @s: the AMDTP stream.
* @channel: the isochronous channel on the bus.
* @speed: firewire speed code.
*/
int amdtp_domain_add_stream(struct amdtp_domain *d, struct amdtp_stream *s,
int channel, int speed)
{
struct amdtp_stream *tmp;
list_for_each_entry(tmp, &d->streams, list) {
if (s == tmp)
return -EBUSY;
}
list_add(&s->list, &d->streams);
s->channel = channel;
s->speed = speed;
return 0;
}
EXPORT_SYMBOL_GPL(amdtp_domain_add_stream);
static int get_current_cycle_time(struct fw_card *fw_card, int *cur_cycle)
{
int generation;
int rcode;
__be32 reg;
u32 data;
// This is a request to local 1394 OHCI controller and expected to
// complete without any event waiting.
generation = fw_card->generation;
smp_rmb(); // node_id vs. generation.
rcode = fw_run_transaction(fw_card, TCODE_READ_QUADLET_REQUEST,
fw_card->node_id, generation, SCODE_100,
CSR_REGISTER_BASE + CSR_CYCLE_TIME,
&reg, sizeof(reg));
if (rcode != RCODE_COMPLETE)
return -EIO;
data = be32_to_cpu(reg);
*cur_cycle = data >> 12;
return 0;
}
/**
* amdtp_domain_start - start sending packets for isoc context in the domain.
* @d: the AMDTP domain.
* @ir_delay_cycle: the cycle delay to start all IR contexts.
*/
int amdtp_domain_start(struct amdtp_domain *d, unsigned int ir_delay_cycle)
{
struct amdtp_stream *s;
int cycle;
int err;
// Select an IT context as IRQ target.
list_for_each_entry(s, &d->streams, list) {
if (s->direction == AMDTP_OUT_STREAM)
break;
}
if (!s)
return -ENXIO;
d->irq_target = s;
if (ir_delay_cycle > 0) {
struct fw_card *fw_card = fw_parent_device(s->unit)->card;
err = get_current_cycle_time(fw_card, &cycle);
if (err < 0)
return err;
// No need to care overflow in cycle field because of enough
// width.
cycle += ir_delay_cycle;
// Round up to sec field.
if ((cycle & 0x00001fff) >= CYCLES_PER_SECOND) {
unsigned int sec;
// The sec field can overflow.
sec = (cycle & 0xffffe000) >> 13;
cycle = (++sec << 13) |
((cycle & 0x00001fff) / CYCLES_PER_SECOND);
}
// In OHCI 1394 specification, lower 2 bits are available for
// sec field.
cycle &= 0x00007fff;
} else {
cycle = -1;
}
list_for_each_entry(s, &d->streams, list) {
int cycle_match;
if (s->direction == AMDTP_IN_STREAM) {
cycle_match = cycle;
} else {
// IT context starts immediately.
cycle_match = -1;
}
if (s != d->irq_target) {
err = amdtp_stream_start(s, s->channel, s->speed, d,
false, cycle_match);
if (err < 0)
goto error;
}
}
s = d->irq_target;
err = amdtp_stream_start(s, s->channel, s->speed, d, true, -1);
if (err < 0)
goto error;
return 0;
error:
list_for_each_entry(s, &d->streams, list)
amdtp_stream_stop(s);
return err;
}
EXPORT_SYMBOL_GPL(amdtp_domain_start);
/**
* amdtp_domain_stop - stop sending packets for isoc context in the same domain.
* @d: the AMDTP domain to which the isoc contexts belong.
*/
void amdtp_domain_stop(struct amdtp_domain *d)
{
struct amdtp_stream *s, *next;
if (d->irq_target)
amdtp_stream_stop(d->irq_target);
list_for_each_entry_safe(s, next, &d->streams, list) {
list_del(&s->list);
if (s != d->irq_target)
amdtp_stream_stop(s);
}
d->events_per_period = 0;
d->irq_target = NULL;
}
EXPORT_SYMBOL_GPL(amdtp_domain_stop);