amdtp-stream.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)
#define OHCI_MAX_SECOND 8
/* 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_work(struct work_struct *work);
/**
* 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);
INIT_WORK(&s->period_work, pcm_period_work);
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 work 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)
{
cancel_work_sync(&s->period_work);
s->pcm_buffer_pointer = 0;
s->pcm_period_pointer = 0;
}
EXPORT_SYMBOL(amdtp_stream_pcm_prepare);
static unsigned int calculate_data_blocks(unsigned int *data_block_state,
bool is_blocking, bool is_no_info,
unsigned int syt_interval, enum cip_sfc sfc)
{
unsigned int data_blocks;
/* Blocking mode. */
if (is_blocking) {
/* This module generate empty packet for 'no data'. */
if (is_no_info)
data_blocks = 0;
else
data_blocks = syt_interval;
/* Non-blocking mode. */
} else {
if (!cip_sfc_is_base_44100(sfc)) {
// Sample_rate / 8000 is an integer, and precomputed.
data_blocks = *data_block_state;
} else {
unsigned int phase = *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 (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 * (sfc >> 1) + (phase == 0);
if (++phase >= (80 >> (sfc >> 1)))
phase = 0;
*data_block_state = phase;
}
}
return data_blocks;
}
static unsigned int calculate_syt_offset(unsigned int *last_syt_offset,
unsigned int *syt_offset_state, enum cip_sfc sfc)
{
unsigned int syt_offset;
if (*last_syt_offset < TICKS_PER_CYCLE) {
if (!cip_sfc_is_base_44100(sfc))
syt_offset = *last_syt_offset + *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.
*/
unsigned int phase = *syt_offset_state;
unsigned int index = phase % 13;
syt_offset = *last_syt_offset;
syt_offset += 1386 + ((index && !(index & 3)) ||
phase == 146);
if (++phase >= 147)
phase = 0;
*syt_offset_state = phase;
}
} else
syt_offset = *last_syt_offset - TICKS_PER_CYCLE;
*last_syt_offset = syt_offset;
if (syt_offset >= TICKS_PER_CYCLE)
syt_offset = CIP_SYT_NO_INFO;
return syt_offset;
}
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;
queue_work(system_highpri_wq, &s->period_work);
}
}
static void pcm_period_work(struct work_struct *work)
{
struct amdtp_stream *s = container_of(work, struct amdtp_stream,
period_work);
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, s->packet_index, 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 packet_index, unsigned int index)
{
const __be32 *cip_header;
unsigned int cip_header_size;
int err;
*payload_length = be32_to_cpu(ctx_header[0]) >> ISO_DATA_LENGTH_SHIFT;
if (!(s->flags & CIP_NO_HEADER))
cip_header_size = 8;
else
cip_header_size = 0;
if (*payload_length > cip_header_size + s->ctx_data.tx.max_ctx_payload_length) {
dev_err(&s->unit->device,
"Detect jumbo payload: %04x %04x\n",
*payload_length, cip_header_size + s->ctx_data.tx.max_ctx_payload_length);
return -EIO;
}
if (cip_header_size > 0) {
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, packet_index, 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 >= OHCI_MAX_SECOND * CYCLES_PER_SECOND)
cycle -= OHCI_MAX_SECOND * 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;
unsigned int packet_index = s->packet_index;
unsigned int queue_size = s->queue_size;
int i;
int err;
for (i = 0; i < packets; ++i) {
struct pkt_desc *desc = descs + i;
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, packet_index, 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[packet_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);
packet_index = (packet_index + 1) % queue_size;
}
s->data_block_counter = dbc;
return 0;
}
static unsigned int compute_syt(unsigned int syt_offset, unsigned int cycle,
unsigned int transfer_delay)
{
unsigned int syt;
syt_offset += transfer_delay;
syt = ((cycle + syt_offset / TICKS_PER_CYCLE) << 12) |
(syt_offset % TICKS_PER_CYCLE);
return syt & CIP_SYT_MASK;
}
static void generate_pkt_descs(struct amdtp_stream *s, struct pkt_desc *descs,
const __be32 *ctx_header, unsigned int packets,
const struct seq_desc *seq_descs,
unsigned int seq_size)
{
unsigned int dbc = s->data_block_counter;
unsigned int seq_index = s->ctx_data.rx.seq_index;
int i;
for (i = 0; i < packets; ++i) {
struct pkt_desc *desc = descs + i;
unsigned int index = (s->packet_index + i) % s->queue_size;
const struct seq_desc *seq = seq_descs + seq_index;
unsigned int syt;
desc->cycle = compute_it_cycle(*ctx_header, s->queue_size);
syt = seq->syt_offset;
if (syt != CIP_SYT_NO_INFO) {
syt = compute_syt(syt, desc->cycle,
s->ctx_data.rx.transfer_delay);
}
desc->syt = syt;
desc->data_blocks = seq->data_blocks;
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;
seq_index = (seq_index + 1) % seq_size;
++ctx_header;
}
s->data_block_counter = dbc;
s->ctx_data.rx.seq_index = seq_index;
}
static inline void cancel_stream(struct amdtp_stream *s)
{
s->packet_index = -1;
if (current_work() == &s->period_work)
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 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 struct amdtp_domain *d = s->domain;
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;
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_pkt_descs(s, s->pkt_descs, ctx_header, packets, d->seq_descs,
d->seq_size);
process_ctx_payloads(s, s->pkt_descs, packets);
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 (s == s->domain->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, ¶ms) < 0) {
cancel_stream(s);
return;
}
}
}
static void pool_ideal_seq_descs(struct amdtp_domain *d, unsigned int packets)
{
struct amdtp_stream *irq_target = d->irq_target;
unsigned int seq_tail = d->seq_tail;
unsigned int seq_size = d->seq_size;
unsigned int min_avail;
struct amdtp_stream *s;
min_avail = d->seq_size;
list_for_each_entry(s, &d->streams, list) {
unsigned int seq_index;
unsigned int avail;
if (s->direction == AMDTP_IN_STREAM)
continue;
seq_index = s->ctx_data.rx.seq_index;
avail = d->seq_tail;
if (seq_index > avail)
avail += d->seq_size;
avail -= seq_index;
if (avail < min_avail)
min_avail = avail;
}
while (min_avail < packets) {
struct seq_desc *desc = d->seq_descs + seq_tail;
desc->syt_offset = calculate_syt_offset(&d->last_syt_offset,
&d->syt_offset_state, irq_target->sfc);
desc->data_blocks = calculate_data_blocks(&d->data_block_state,
!!(irq_target->flags & CIP_BLOCKING),
desc->syt_offset == CIP_SYT_NO_INFO,
irq_target->syt_interval, irq_target->sfc);
++seq_tail;
seq_tail %= seq_size;
++min_avail;
}
d->seq_tail = seq_tail;
}
static void irq_target_callback(struct fw_iso_context *context, u32 tstamp,
size_t header_length, void *header,
void *private_data)
{
struct amdtp_stream *irq_target = private_data;
struct amdtp_domain *d = irq_target->domain;
unsigned int packets = header_length / sizeof(__be32);
struct amdtp_stream *s;
// Record enough entries with extra 3 cycles at least.
pool_ideal_seq_descs(d, packets + 3);
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);
if (s == s->domain->irq_target)
context->callback.sc = irq_target_callback;
else
context->callback.sc = out_stream_callback;
}
s->start_cycle = cycle;
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
* @start_cycle: the isochronous cycle to start the context. Start immediately
* if negative value is given.
* @queue_size: The number of packets in the queue.
* @idle_irq_interval: the interval to queue packet during initial state.
*
* 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,
int start_cycle, unsigned int queue_size,
unsigned int idle_irq_interval)
{
bool is_irq_target = (s == s->domain->irq_target);
unsigned int ctx_header_size;
unsigned int max_ctx_payload_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) {
// 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 {
s->data_block_counter = 0;
}
// initialize packet buffer.
max_ctx_payload_size = amdtp_stream_get_max_payload(s);
if (s->direction == AMDTP_IN_STREAM) {
dir = DMA_FROM_DEVICE;
type = FW_ISO_CONTEXT_RECEIVE;
if (!(s->flags & CIP_NO_HEADER)) {
max_ctx_payload_size -= 8;
ctx_header_size = IR_CTX_HEADER_SIZE_CIP;
} else {
ctx_header_size = IR_CTX_HEADER_SIZE_NO_CIP;
}
} else {
dir = DMA_TO_DEVICE;
type = FW_ISO_CONTEXT_TRANSMIT;
ctx_header_size = 0; // No effect for IT context.
if (!(s->flags & CIP_NO_HEADER))
max_ctx_payload_size -= IT_PKT_HEADER_SIZE_CIP;
}
err = iso_packets_buffer_init(&s->buffer, s->unit, queue_size,
max_ctx_payload_size, dir);
if (err < 0)
goto err_unlock;
s->queue_size = queue_size;
s->context = fw_iso_context_create(fw_parent_device(s->unit)->card,
type, channel, speed, ctx_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);
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, ¶ms);
} 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, ¶ms, 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_work 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_work. Then, no need to flush the
// queue by the same reason as described in the above
if (current_work() != &s->period_work) {
// 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;
}
cancel_work_sync(&s->period_work);
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;
d->seq_descs = NULL;
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;
s->domain = d;
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,
®, 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)
{
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 queue_size;
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;
// 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[d->irq_target->sfc] / 100;
if (events_per_buffer == 0)
events_per_buffer = events_per_period * 3;
queue_size = DIV_ROUND_UP(CYCLES_PER_SECOND * events_per_buffer,
amdtp_rate_table[d->irq_target->sfc]);
d->seq_descs = kcalloc(queue_size, sizeof(*d->seq_descs), GFP_KERNEL);
if (!d->seq_descs)
return -ENOMEM;
d->seq_size = queue_size;
d->seq_tail = 0;
entry = &initial_state[s->sfc];
d->data_block_state = entry->data_block;
d->syt_offset_state = entry->syt_offset;
d->last_syt_offset = TICKS_PER_CYCLE;
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)
goto error;
// 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;
s->ctx_data.rx.seq_index = 0;
}
if (s != d->irq_target) {
err = amdtp_stream_start(s, s->channel, s->speed,
cycle_match, queue_size, 0);
if (err < 0)
goto error;
}
}
s = d->irq_target;
s->ctx_data.rx.events_per_period = events_per_period;
s->ctx_data.rx.event_count = 0;
s->ctx_data.rx.seq_index = 0;
idle_irq_interval = DIV_ROUND_UP(CYCLES_PER_SECOND * events_per_period,
amdtp_rate_table[d->irq_target->sfc]);
err = amdtp_stream_start(s, s->channel, s->speed, -1, queue_size,
idle_irq_interval);
if (err < 0)
goto error;
return 0;
error:
list_for_each_entry(s, &d->streams, list)
amdtp_stream_stop(s);
kfree(d->seq_descs);
d->seq_descs = NULL;
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;
kfree(d->seq_descs);
d->seq_descs = NULL;
}
EXPORT_SYMBOL_GPL(amdtp_domain_stop);
