/* * Audio and Music Data Transmission Protocol (IEC 61883-6) streams * with Common Isochronous Packet (IEC 61883-1) headers * * Copyright (c) Clemens Ladisch * Licensed under the terms of the GNU General Public License, version 2. */ #include #include #include #include #include #include #include #include #include #include "amdtp.h" #define TICKS_PER_CYCLE 3072 #define CYCLES_PER_SECOND 8000 #define TICKS_PER_SECOND (TICKS_PER_CYCLE * CYCLES_PER_SECOND) /* * Nominally 3125 bytes/second, but the MIDI port's clock might be * 1% too slow, and the bus clock 100 ppm too fast. */ #define MIDI_BYTES_PER_SECOND 3093 /* * Several devices look only at the first eight data blocks. * In any case, this is more than enough for the MIDI data rate. */ #define MAX_MIDI_RX_BLOCKS 8 #define TRANSFER_DELAY_TICKS 0x2e00 /* 479.17 µs */ /* isochronous header parameters */ #define ISO_DATA_LENGTH_SHIFT 16 #define TAG_CIP 1 /* common isochronous packet header parameters */ #define CIP_EOH (1u << 31) #define CIP_EOH_MASK 0x80000000 #define CIP_FMT_AM (0x10 << 24) #define CIP_FMT_MASK 0x3f000000 #define CIP_SYT_MASK 0x0000ffff #define CIP_SYT_NO_INFO 0xffff #define CIP_FDF_MASK 0x00ff0000 #define CIP_FDF_SFC_SHIFT 16 /* * Audio and Music transfer protocol specific parameters * only "Clock-based rate control mode" is supported */ #define AMDTP_FDF_AM824 (0 << (CIP_FDF_SFC_SHIFT + 3)) #define AMDTP_FDF_NO_DATA 0xff #define AMDTP_DBS_MASK 0x00ff0000 #define AMDTP_DBS_SHIFT 16 #define AMDTP_DBC_MASK 0x000000ff /* 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 */ int amdtp_stream_init(struct amdtp_stream *s, struct fw_unit *unit, enum amdtp_stream_direction dir, enum cip_flags flags) { s->unit = fw_unit_get(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; 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)); mutex_destroy(&s->mutex); fw_unit_put(s->unit); } 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; /* AM824 in IEC 61883-6 can deliver 24bit data */ err = snd_pcm_hw_constraint_msbits(runtime, 0, 32, 24); if (err < 0) goto end; /* * 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 aligh period/buffer sizes to current SYT_INTERVAL. * * TODO: These constraints can be improved with propper rules. * Currently apply LCM of SYT_INTEVALs. */ 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 * @pcm_channels: the number of PCM samples in each data block, to be encoded * as AM824 multi-bit linear audio * @midi_ports: the number of MIDI ports (i.e., MPX-MIDI Data Channels) * * The parameters must be set before the stream is started, and must not be * changed while the stream is running. */ void amdtp_stream_set_parameters(struct amdtp_stream *s, unsigned int rate, unsigned int pcm_channels, unsigned int midi_ports) { unsigned int i, sfc, midi_channels; midi_channels = DIV_ROUND_UP(midi_ports, 8); if (WARN_ON(amdtp_stream_running(s)) | WARN_ON(pcm_channels > AMDTP_MAX_CHANNELS_FOR_PCM) | WARN_ON(midi_channels > AMDTP_MAX_CHANNELS_FOR_MIDI)) return; for (sfc = 0; sfc < ARRAY_SIZE(amdtp_rate_table); ++sfc) if (amdtp_rate_table[sfc] == rate) goto sfc_found; WARN_ON(1); return; sfc_found: s->pcm_channels = pcm_channels; s->sfc = sfc; s->data_block_quadlets = s->pcm_channels + midi_channels; s->midi_ports = midi_ports; 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; /* init the position map for PCM and MIDI channels */ for (i = 0; i < pcm_channels; i++) s->pcm_positions[i] = i; s->midi_position = s->pcm_channels; /* * We do not know the actual MIDI FIFO size of most devices. Just * assume two bytes, i.e., one byte can be received over the bus while * the previous one is transmitted over MIDI. * (The value here is adjusted for midi_ratelimit_per_packet().) */ s->midi_fifo_limit = rate - MIDI_BYTES_PER_SECOND * s->syt_interval + 1; } 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) { return 8 + s->syt_interval * s->data_block_quadlets * 4; } EXPORT_SYMBOL(amdtp_stream_get_max_payload); static void amdtp_write_s16(struct amdtp_stream *s, struct snd_pcm_substream *pcm, __be32 *buffer, unsigned int frames); static void amdtp_write_s32(struct amdtp_stream *s, struct snd_pcm_substream *pcm, __be32 *buffer, unsigned int frames); static void amdtp_read_s32(struct amdtp_stream *s, struct snd_pcm_substream *pcm, __be32 *buffer, unsigned int frames); /** * amdtp_stream_set_pcm_format - set the PCM format * @s: the AMDTP stream to configure * @format: the format of the ALSA PCM device * * The sample format must be set after the other paramters (rate/PCM channels/ * MIDI) and before the stream is started, and must not be changed while the * stream is running. */ void amdtp_stream_set_pcm_format(struct amdtp_stream *s, snd_pcm_format_t format) { if (WARN_ON(amdtp_stream_pcm_running(s))) return; switch (format) { default: WARN_ON(1); /* fall through */ case SNDRV_PCM_FORMAT_S16: if (s->direction == AMDTP_OUT_STREAM) { s->transfer_samples = amdtp_write_s16; break; } WARN_ON(1); /* fall through */ case SNDRV_PCM_FORMAT_S32: if (s->direction == AMDTP_OUT_STREAM) s->transfer_samples = amdtp_write_s32; else s->transfer_samples = amdtp_read_s32; break; } } EXPORT_SYMBOL(amdtp_stream_set_pcm_format); /** * 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 phase, data_blocks; if (s->flags & CIP_BLOCKING) data_blocks = s->syt_interval; 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 amdtp_write_s32(struct amdtp_stream *s, struct snd_pcm_substream *pcm, __be32 *buffer, unsigned int frames) { struct snd_pcm_runtime *runtime = pcm->runtime; unsigned int channels, remaining_frames, i, c; const u32 *src; channels = s->pcm_channels; src = (void *)runtime->dma_area + frames_to_bytes(runtime, s->pcm_buffer_pointer); remaining_frames = runtime->buffer_size - s->pcm_buffer_pointer; for (i = 0; i < frames; ++i) { for (c = 0; c < channels; ++c) { buffer[s->pcm_positions[c]] = cpu_to_be32((*src >> 8) | 0x40000000); src++; } buffer += s->data_block_quadlets; if (--remaining_frames == 0) src = (void *)runtime->dma_area; } } static void amdtp_write_s16(struct amdtp_stream *s, struct snd_pcm_substream *pcm, __be32 *buffer, unsigned int frames) { struct snd_pcm_runtime *runtime = pcm->runtime; unsigned int channels, remaining_frames, i, c; const u16 *src; channels = s->pcm_channels; src = (void *)runtime->dma_area + frames_to_bytes(runtime, s->pcm_buffer_pointer); remaining_frames = runtime->buffer_size - s->pcm_buffer_pointer; for (i = 0; i < frames; ++i) { for (c = 0; c < channels; ++c) { buffer[s->pcm_positions[c]] = cpu_to_be32((*src << 8) | 0x42000000); src++; } buffer += s->data_block_quadlets; if (--remaining_frames == 0) src = (void *)runtime->dma_area; } } static void amdtp_read_s32(struct amdtp_stream *s, struct snd_pcm_substream *pcm, __be32 *buffer, unsigned int frames) { struct snd_pcm_runtime *runtime = pcm->runtime; unsigned int channels, remaining_frames, i, c; u32 *dst; channels = s->pcm_channels; dst = (void *)runtime->dma_area + frames_to_bytes(runtime, s->pcm_buffer_pointer); remaining_frames = runtime->buffer_size - s->pcm_buffer_pointer; for (i = 0; i < frames; ++i) { for (c = 0; c < channels; ++c) { *dst = be32_to_cpu(buffer[s->pcm_positions[c]]) << 8; dst++; } buffer += s->data_block_quadlets; if (--remaining_frames == 0) dst = (void *)runtime->dma_area; } } static void amdtp_fill_pcm_silence(struct amdtp_stream *s, __be32 *buffer, unsigned int frames) { unsigned int i, c; for (i = 0; i < frames; ++i) { for (c = 0; c < s->pcm_channels; ++c) buffer[s->pcm_positions[c]] = cpu_to_be32(0x40000000); buffer += s->data_block_quadlets; } } /* * To avoid sending MIDI bytes at too high a rate, assume that the receiving * device has a FIFO, and track how much it is filled. This values increases * by one whenever we send one byte in a packet, but the FIFO empties at * a constant rate independent of our packet rate. One packet has syt_interval * samples, so the number of bytes that empty out of the FIFO, per packet(!), * is MIDI_BYTES_PER_SECOND * syt_interval / sample_rate. To avoid storing * fractional values, the values in midi_fifo_used[] are measured in bytes * multiplied by the sample rate. */ static bool midi_ratelimit_per_packet(struct amdtp_stream *s, unsigned int port) { int used; used = s->midi_fifo_used[port]; if (used == 0) /* common shortcut */ return true; used -= MIDI_BYTES_PER_SECOND * s->syt_interval; used = max(used, 0); s->midi_fifo_used[port] = used; return used < s->midi_fifo_limit; } static void midi_rate_use_one_byte(struct amdtp_stream *s, unsigned int port) { s->midi_fifo_used[port] += amdtp_rate_table[s->sfc]; } static void amdtp_fill_midi(struct amdtp_stream *s, __be32 *buffer, unsigned int frames) { unsigned int f, port; u8 *b; for (f = 0; f < frames; f++) { b = (u8 *)&buffer[s->midi_position]; port = (s->data_block_counter + f) % 8; if (f < MAX_MIDI_RX_BLOCKS && midi_ratelimit_per_packet(s, port) && s->midi[port] != NULL && snd_rawmidi_transmit(s->midi[port], &b[1], 1) == 1) { midi_rate_use_one_byte(s, port); b[0] = 0x81; } else { b[0] = 0x80; b[1] = 0; } b[2] = 0; b[3] = 0; buffer += s->data_block_quadlets; } } static void amdtp_pull_midi(struct amdtp_stream *s, __be32 *buffer, unsigned int frames) { unsigned int f, port; int len; u8 *b; for (f = 0; f < frames; f++) { port = (s->data_block_counter + f) % 8; b = (u8 *)&buffer[s->midi_position]; len = b[0] - 0x80; if ((1 <= len) && (len <= 3) && (s->midi[port])) snd_rawmidi_receive(s->midi[port], b + 1, len); buffer += s->data_block_quadlets; } } static void update_pcm_pointers(struct amdtp_stream *s, struct snd_pcm_substream *pcm, unsigned int frames) { unsigned int ptr; /* * In IEC 61883-6, one data block represents one event. In ALSA, one * event equals to one PCM frame. But Dice has a quirk to transfer * two PCM frames in one data block. */ if (s->double_pcm_frames) frames *= 2; 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 void handle_out_packet(struct amdtp_stream *s, unsigned int syt) { __be32 *buffer; unsigned int data_blocks, payload_length; struct snd_pcm_substream *pcm; if (s->packet_index < 0) return; /* this module generate empty packet for 'no data' */ if (!(s->flags & CIP_BLOCKING) || (syt != CIP_SYT_NO_INFO)) data_blocks = calculate_data_blocks(s); else data_blocks = 0; buffer = s->buffer.packets[s->packet_index].buffer; buffer[0] = cpu_to_be32(ACCESS_ONCE(s->source_node_id_field) | (s->data_block_quadlets << AMDTP_DBS_SHIFT) | s->data_block_counter); buffer[1] = cpu_to_be32(CIP_EOH | CIP_FMT_AM | AMDTP_FDF_AM824 | (s->sfc << CIP_FDF_SFC_SHIFT) | syt); buffer += 2; pcm = ACCESS_ONCE(s->pcm); if (pcm) s->transfer_samples(s, pcm, buffer, data_blocks); else amdtp_fill_pcm_silence(s, buffer, data_blocks); if (s->midi_ports) amdtp_fill_midi(s, buffer, data_blocks); 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) { s->packet_index = -1; amdtp_stream_pcm_abort(s); return; } if (pcm) update_pcm_pointers(s, pcm, data_blocks); } static void handle_in_packet(struct amdtp_stream *s, unsigned int payload_quadlets, __be32 *buffer) { u32 cip_header[2]; unsigned int data_blocks, data_block_quadlets, data_block_counter, dbc_interval; struct snd_pcm_substream *pcm = NULL; 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) || ((cip_header[1] & CIP_FMT_MASK) != CIP_FMT_AM)) { dev_info_ratelimited(&s->unit->device, "Invalid CIP header for AMDTP: %08X:%08X\n", cip_header[0], cip_header[1]); goto end; } /* Calculate data blocks */ if (payload_quadlets < 3 || ((cip_header[1] & CIP_FDF_MASK) == (AMDTP_FDF_NO_DATA << CIP_FDF_SFC_SHIFT))) { data_blocks = 0; } else { data_block_quadlets = (cip_header[0] & AMDTP_DBS_MASK) >> AMDTP_DBS_SHIFT; /* avoid division by zero */ if (data_block_quadlets == 0) { dev_info_ratelimited(&s->unit->device, "Detect invalid value in dbs field: %08X\n", cip_header[0]); goto err; } 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] & AMDTP_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 == 0) || (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_info(&s->unit->device, "Detect discontinuity of CIP: %02X %02X\n", s->data_block_counter, data_block_counter); goto err; } if (data_blocks > 0) { buffer += 2; pcm = ACCESS_ONCE(s->pcm); if (pcm) s->transfer_samples(s, pcm, buffer, data_blocks); if (s->midi_ports) amdtp_pull_midi(s, buffer, data_blocks); } 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) goto err; if (pcm) update_pcm_pointers(s, pcm, data_blocks); return; err: s->packet_index = -1; amdtp_stream_pcm_abort(s); } 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; /* * 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); handle_out_packet(s, syt); } 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, payload_quadlets; __be32 *buffer, *headers = header; /* The number of packets in buffer */ packets = header_length / IN_PACKET_HEADER_SIZE; for (p = 0; p < packets; p++) { if (s->packet_index < 0) break; buffer = s->buffer.packets[s->packet_index].buffer; /* Process sync slave stream */ if (s->sync_slave && s->sync_slave->callbacked) { syt = be32_to_cpu(buffer[1]) & CIP_SYT_MASK; handle_out_packet(s->sync_slave, syt); } /* The number of quadlets in this packet */ payload_quadlets = (be32_to_cpu(headers[p]) >> ISO_DATA_LENGTH_SHIFT) / 4; handle_in_packet(s, payload_quadlets, buffer); } /* Queueing error or detecting discontinuity */ if (s->packet_index < 0) { /* 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_BLOCKING) && (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) { ACCESS_ONCE(s->source_node_id_field) = (fw_parent_device(s->unit)->card->node_id & 0x3f) << 24; } 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);