diff options
Diffstat (limited to 'kernel/sound/firewire/amdtp-stream.c')
| -rw-r--r-- | kernel/sound/firewire/amdtp-stream.c | 863 |
1 files changed, 863 insertions, 0 deletions
diff --git a/kernel/sound/firewire/amdtp-stream.c b/kernel/sound/firewire/amdtp-stream.c new file mode 100644 index 000000000..ed2902609 --- /dev/null +++ b/kernel/sound/firewire/amdtp-stream.c @@ -0,0 +1,863 @@ +/* + * 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) + +#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->sync_slave = NULL; + + 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) +{ + 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; + s->pointer_flush = true; +} +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; + s->pointer_flush = false; + 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, bool skip) +{ + 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; + p.payload_length = (!skip) ? payload_length : 0; + p.skip = skip; + 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, bool skip) +{ + return queue_packet(s, OUT_PACKET_HEADER_SIZE, + payload_length, skip); +} + +static inline int queue_in_packet(struct amdtp_stream *s) +{ + return queue_packet(s, IN_PACKET_HEADER_SIZE, + amdtp_stream_get_max_payload(s), false); +} + +static int handle_out_packet(struct amdtp_stream *s, unsigned int data_blocks, + unsigned int syt) +{ + __be32 *buffer; + unsigned int payload_length; + unsigned int pcm_frames; + struct snd_pcm_substream *pcm; + + buffer = s->buffer.packets[s->packet_index].buffer; + 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; + if (queue_out_packet(s, payload_length, false) < 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, __be32 *buffer, + unsigned int *data_blocks, unsigned int syt) +{ + u32 cip_header[2]; + unsigned int fmt, fdf; + unsigned int data_block_quadlets, data_block_counter, dbc_interval; + struct snd_pcm_substream *pcm; + unsigned int pcm_frames; + bool lost; + + cip_header[0] = be32_to_cpu(buffer[0]); + cip_header[1] = be32_to_cpu(buffer[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)) { + 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; + } + + 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; +} + +static void out_stream_callback(struct fw_iso_context *context, u32 cycle, + size_t header_length, void *header, + void *private_data) +{ + struct amdtp_stream *s = private_data; + unsigned int i, syt, packets = header_length / 4; + unsigned int data_blocks; + + if (s->packet_index < 0) + return; + + /* + * Compute the cycle of the last queued packet. + * (We need only the four lowest bits for the SYT, so we can ignore + * that bits 0-11 must wrap around at 3072.) + */ + cycle += QUEUE_LENGTH - packets; + + for (i = 0; i < packets; ++i) { + syt = calculate_syt(s, ++cycle); + data_blocks = calculate_data_blocks(s, syt); + + if (handle_out_packet(s, data_blocks, syt) < 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 cycle, + size_t header_length, void *header, + void *private_data) +{ + struct amdtp_stream *s = private_data; + unsigned int p, syt, packets; + unsigned int payload_quadlets, max_payload_quadlets; + unsigned int data_blocks; + __be32 *buffer, *headers = header; + + if (s->packet_index < 0) + return; + + /* The number of packets in buffer */ + packets = header_length / IN_PACKET_HEADER_SIZE; + + /* For buffer-over-run prevention. */ + max_payload_quadlets = amdtp_stream_get_max_payload(s) / 4; + + for (p = 0; p < packets; p++) { + buffer = s->buffer.packets[s->packet_index].buffer; + + /* The number of quadlets in this packet */ + payload_quadlets = + (be32_to_cpu(headers[p]) >> 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); + s->packet_index = -1; + break; + } + + syt = be32_to_cpu(buffer[1]) & CIP_SYT_MASK; + if (handle_in_packet(s, payload_quadlets, buffer, + &data_blocks, syt) < 0) { + s->packet_index = -1; + break; + } + + /* Process sync slave stream */ + if (s->sync_slave && s->sync_slave->callbacked) { + if (handle_out_packet(s->sync_slave, + data_blocks, syt) < 0) { + s->packet_index = -1; + break; + } + } + } + + /* Queueing error or detecting discontinuity */ + if (s->packet_index < 0) { + amdtp_stream_pcm_abort(s); + + /* Abort sync slave. */ + if (s->sync_slave) { + s->sync_slave->packet_index = -1; + amdtp_stream_pcm_abort(s->sync_slave); + } + return; + } + + /* when sync to device, flush the packets for slave stream */ + if (s->sync_slave && s->sync_slave->callbacked) + fw_iso_context_queue_flush(s->sync_slave->context); + + fw_iso_context_queue_flush(s->context); +} + +/* processing is done by master callback */ +static void slave_stream_callback(struct fw_iso_context *context, u32 cycle, + size_t header_length, void *header, + void *private_data) +{ + return; +} + +/* this is executed one time */ +static void amdtp_stream_first_callback(struct fw_iso_context *context, + u32 cycle, 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 if (s->flags & CIP_SYNC_TO_DEVICE) + context->callback.sc = slave_stream_callback; + else + context->callback.sc = out_stream_callback; + + context->callback.sc(context, cycle, 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->flags & CIP_SKIP_INIT_DBC_CHECK) + 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, true); + 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 optimization is allowed to be racy */ + if (s->pointer_flush && amdtp_stream_running(s)) + fw_iso_context_flush_completions(s->context); + else + s->pointer_flush = true; + + 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); |