// 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 */ #include #include #include #include #include #include #include #include #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_SECOND_MODULUS 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 (CIP) header parameters. Use two quadlets CIP header when supported. #define CIP_HEADER_QUADLETS 2 #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 #define CIP_HEADER_SIZE (sizeof(__be32) * CIP_HEADER_QUADLETS) /* Audio and Music transfer protocol specific parameters */ #define CIP_FMT_AM 0x10 #define AMDTP_FDF_NO_DATA 0xff // For iso header and tstamp. #define IR_CTX_HEADER_DEFAULT_QUADLETS 2 // Add nothing. #define IR_CTX_HEADER_SIZE_NO_CIP (sizeof(__be32) * IR_CTX_HEADER_DEFAULT_QUADLETS) // Add two quadlets CIP header. #define IR_CTX_HEADER_SIZE_CIP (IR_CTX_HEADER_SIZE_NO_CIP + CIP_HEADER_SIZE) #define HEADER_TSTAMP_MASK 0x0000ffff #define IT_PKT_HEADER_SIZE_CIP CIP_HEADER_SIZE #define IT_PKT_HEADER_SIZE_NO_CIP 0 // Nothing. // The initial firmware of OXFW970 can postpone transmission of packet during finishing // asynchronous transaction. This module accepts 5 cycles to skip as maximum to avoid buffer // overrun. Actual device can skip more, then this module stops the packet streaming. #define IR_JUMBO_PAYLOAD_MAX_SKIP_CYCLES 5 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 details of the streaming protocol consist of cip_flags enumeration-constants. * @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, unsigned int 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); // The CIP header is processed in context header apart from context payload. static int amdtp_stream_get_max_ctx_payload_size(struct amdtp_stream *s) { unsigned int multiplier; if (s->flags & CIP_JUMBO_PAYLOAD) multiplier = IR_JUMBO_PAYLOAD_MAX_SKIP_CYCLES; else multiplier = 1; return s->syt_interval * s->data_block_quadlets * sizeof(__be32) * multiplier; } /** * 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 cip_header_size; if (!(s->flags & CIP_NO_HEADER)) cip_header_size = CIP_HEADER_SIZE; else cip_header_size = 0; return cip_header_size + amdtp_stream_get_max_ctx_payload_size(s); } 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 header_length, 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 (header_length > 0) { cip_header = (__be32 *)params->header; generate_cip_header(s, cip_header, data_block_counter, syt); params->header_length = header_length; } else { cip_header = NULL; } trace_amdtp_packet(s, cycle, cip_header, payload_length + header_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 == 0 || (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) / 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 *data_blocks, unsigned int *data_block_counter, unsigned int *syt, unsigned int packet_index, unsigned int index) { unsigned int payload_length; 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 = CIP_HEADER_SIZE; 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) { if (payload_length >= cip_header_size) { cip_header = ctx_header + IR_CTX_HEADER_DEFAULT_QUADLETS; err = check_cip_header(s, cip_header, payload_length - cip_header_size, data_blocks, data_block_counter, syt); if (err < 0) return err; } else { // Handle the cycle so that empty packet arrives. cip_header = NULL; *data_blocks = 0; *syt = 0; } } 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_ohci_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_ohci_cycle_count(u32 cycle, unsigned int addend) { cycle += addend; if (cycle >= OHCI_SECOND_MODULUS * CYCLES_PER_SECOND) cycle -= OHCI_SECOND_MODULUS * CYCLES_PER_SECOND; return cycle; } static int compare_ohci_cycle_count(u32 lval, u32 rval) { if (lval == rval) return 0; else if (lval < rval && rval - lval < OHCI_SECOND_MODULUS * CYCLES_PER_SECOND / 2) return -1; else return 1; } // 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_ohci_it_cycle(const __be32 ctx_header_tstamp, unsigned int queue_size) { u32 cycle = compute_ohci_cycle_count(ctx_header_tstamp); return increment_ohci_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 *desc_count) { unsigned int next_cycle = s->next_cycle; 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; *desc_count = 0; for (i = 0; i < packets; ++i) { struct pkt_desc *desc = descs + *desc_count; unsigned int cycle; bool lost; unsigned int data_blocks; unsigned int syt; cycle = compute_ohci_cycle_count(ctx_header[1]); lost = (next_cycle != cycle); if (lost) { if (s->flags & CIP_NO_HEADER) { // Fireface skips transmission just for an isoc cycle corresponding // to empty packet. unsigned int prev_cycle = next_cycle; next_cycle = increment_ohci_cycle_count(next_cycle, 1); lost = (next_cycle != cycle); if (!lost) { // Prepare a description for the skipped cycle for // sequence replay. desc->cycle = prev_cycle; desc->syt = 0; desc->data_blocks = 0; desc->data_block_counter = dbc; desc->ctx_payload = NULL; ++desc; ++(*desc_count); } } else if (s->flags & CIP_JUMBO_PAYLOAD) { // OXFW970 skips transmission for several isoc cycles during // asynchronous transaction. The sequence replay is impossible due // to the reason. unsigned int safe_cycle = increment_ohci_cycle_count(next_cycle, IR_JUMBO_PAYLOAD_MAX_SKIP_CYCLES); lost = (compare_ohci_cycle_count(safe_cycle, cycle) > 0); } if (lost) { dev_err(&s->unit->device, "Detect discontinuity of cycle: %d %d\n", next_cycle, cycle); return -EIO; } } err = parse_ir_ctx_header(s, cycle, ctx_header, &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; next_cycle = increment_ohci_cycle_count(next_cycle, 1); ++(*desc_count); ctx_header += s->ctx_data.tx.ctx_header_size / sizeof(*ctx_header); packet_index = (packet_index + 1) % queue_size; } s->next_cycle = next_cycle; 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_ohci_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 process_rx_packets(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; const unsigned int events_per_period = d->events_per_period; unsigned int event_count = s->ctx_data.rx.event_count; unsigned int pkt_header_length; 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); if (!(s->flags & CIP_NO_HEADER)) pkt_header_length = IT_PKT_HEADER_SIZE_CIP; else pkt_header_length = 0; 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[CIP_HEADER_QUADLETS]; } 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, pkt_header_length, 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 skip_rx_packets(struct fw_iso_context *context, u32 tstamp, size_t header_length, void *header, void *private_data) { struct amdtp_stream *s = private_data; struct amdtp_domain *d = s->domain; const __be32 *ctx_header = header; unsigned int packets; unsigned int cycle; int i; if (s->packet_index < 0) return; packets = header_length / sizeof(*ctx_header); cycle = compute_ohci_it_cycle(ctx_header[packets - 1], s->queue_size); s->next_cycle = increment_ohci_cycle_count(cycle, 1); for (i = 0; i < packets; ++i) { struct fw_iso_packet params = { .header_length = 0, .payload_length = 0, }; bool sched_irq = (s == d->irq_target && i == packets - 1); if (queue_out_packet(s, ¶ms, sched_irq) < 0) { cancel_stream(s); return; } } } static void irq_target_callback(struct fw_iso_context *context, u32 tstamp, size_t header_length, void *header, void *private_data); static void process_rx_packets_intermediately(struct fw_iso_context *context, u32 tstamp, size_t header_length, void *header, void *private_data) { struct amdtp_stream *s = private_data; struct amdtp_domain *d = s->domain; __be32 *ctx_header = header; const unsigned int queue_size = s->queue_size; unsigned int packets; unsigned int offset; if (s->packet_index < 0) return; packets = header_length / sizeof(*ctx_header); offset = 0; while (offset < packets) { unsigned int cycle = compute_ohci_it_cycle(ctx_header[offset], queue_size); if (compare_ohci_cycle_count(cycle, d->processing_cycle.rx_start) >= 0) break; ++offset; } if (offset > 0) { unsigned int length = sizeof(*ctx_header) * offset; skip_rx_packets(context, tstamp, length, ctx_header, private_data); if (amdtp_streaming_error(s)) return; ctx_header += offset; header_length -= length; } if (offset < packets) { process_rx_packets(context, tstamp, header_length, ctx_header, private_data); if (amdtp_streaming_error(s)) return; if (s == d->irq_target) s->context->callback.sc = irq_target_callback; else s->context->callback.sc = process_rx_packets; } } static void process_tx_packets(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; unsigned int desc_count; 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; desc_count = 0; err = generate_device_pkt_descs(s, s->pkt_descs, ctx_header, packets, &desc_count); if (err < 0) { if (err != -EAGAIN) { cancel_stream(s); return; } } else { process_ctx_payloads(s, s->pkt_descs, desc_count); } 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 drop_tx_packets(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 packets; unsigned int cycle; int i; if (s->packet_index < 0) return; packets = header_length / s->ctx_data.tx.ctx_header_size; ctx_header += (packets - 1) * s->ctx_data.tx.ctx_header_size / sizeof(*ctx_header); cycle = compute_ohci_cycle_count(ctx_header[1]); s->next_cycle = increment_ohci_cycle_count(cycle, 1); 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 process_tx_packets_intermediately(struct fw_iso_context *context, u32 tstamp, size_t header_length, void *header, void *private_data) { struct amdtp_stream *s = private_data; struct amdtp_domain *d = s->domain; __be32 *ctx_header; unsigned int packets; unsigned int offset; if (s->packet_index < 0) return; packets = header_length / s->ctx_data.tx.ctx_header_size; offset = 0; ctx_header = header; while (offset < packets) { unsigned int cycle = compute_ohci_cycle_count(ctx_header[1]); if (compare_ohci_cycle_count(cycle, d->processing_cycle.tx_start) >= 0) break; ctx_header += s->ctx_data.tx.ctx_header_size / sizeof(__be32); ++offset; } ctx_header = header; if (offset > 0) { size_t length = s->ctx_data.tx.ctx_header_size * offset; drop_tx_packets(context, tstamp, length, ctx_header, s); if (amdtp_streaming_error(s)) return; ctx_header += length / sizeof(*ctx_header); header_length -= length; } if (offset < packets) { process_tx_packets(context, tstamp, header_length, ctx_header, s); if (amdtp_streaming_error(s)) return; context->callback.sc = process_tx_packets; } } 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 process_ctxs_in_domain(struct amdtp_domain *d) { struct amdtp_stream *s; list_for_each_entry(s, &d->streams, list) { if (s != d->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(d->irq_target)) cancel_stream(d->irq_target); list_for_each_entry(s, &d->streams, list) { if (amdtp_stream_running(s)) cancel_stream(s); } } static void irq_target_callback(struct fw_iso_context *context, u32 tstamp, size_t header_length, void *header, void *private_data) { struct amdtp_stream *s = private_data; struct amdtp_domain *d = s->domain; unsigned int packets = header_length / sizeof(__be32); pool_ideal_seq_descs(d, packets); process_rx_packets(context, tstamp, header_length, header, private_data); process_ctxs_in_domain(d); } static void irq_target_callback_intermediately(struct fw_iso_context *context, u32 tstamp, size_t header_length, void *header, void *private_data) { struct amdtp_stream *s = private_data; struct amdtp_domain *d = s->domain; unsigned int packets = header_length / sizeof(__be32); pool_ideal_seq_descs(d, packets); process_rx_packets_intermediately(context, tstamp, header_length, header, private_data); process_ctxs_in_domain(d); } static void irq_target_callback_skip(struct fw_iso_context *context, u32 tstamp, size_t header_length, void *header, void *private_data) { struct amdtp_stream *s = private_data; struct amdtp_domain *d = s->domain; unsigned int cycle; skip_rx_packets(context, tstamp, header_length, header, private_data); process_ctxs_in_domain(d); // Decide the cycle count to begin processing content of packet in IT contexts. All of IT // contexts are expected to start and get callback when reaching here. cycle = s->next_cycle; list_for_each_entry(s, &d->streams, list) { if (s->direction != AMDTP_OUT_STREAM) continue; if (compare_ohci_cycle_count(s->next_cycle, cycle) > 0) cycle = s->next_cycle; if (s == d->irq_target) s->context->callback.sc = irq_target_callback_intermediately; else s->context->callback.sc = process_rx_packets_intermediately; } d->processing_cycle.rx_start = cycle; } // 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; struct amdtp_domain *d = s->domain; 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_ohci_cycle_count(ctx_header[1]); context->callback.sc = drop_tx_packets; } else { cycle = compute_ohci_it_cycle(*ctx_header, s->queue_size); if (s == d->irq_target) context->callback.sc = irq_target_callback_skip; else context->callback.sc = skip_rx_packets; } context->callback.sc(context, tstamp, header_length, header, s); // Decide the cycle count to begin processing content of packet in IR contexts. if (s->direction == AMDTP_IN_STREAM) { unsigned int stream_count = 0; unsigned int callbacked_count = 0; list_for_each_entry(s, &d->streams, list) { if (s->direction == AMDTP_IN_STREAM) { ++stream_count; if (s->callbacked) ++callbacked_count; } } if (stream_count == callbacked_count) { unsigned int next_cycle; list_for_each_entry(s, &d->streams, list) { if (s->direction != AMDTP_IN_STREAM) continue; next_cycle = increment_ohci_cycle_count(s->next_cycle, d->processing_cycle.tx_init_skip); if (compare_ohci_cycle_count(next_cycle, cycle) > 0) cycle = next_cycle; s->context->callback.sc = process_tx_packets_intermediately; } d->processing_cycle.tx_start = cycle; } } } /** * amdtp_stream_start - start transferring packets * @s: the AMDTP stream to start * @channel: the isochronous channel on the bus * @speed: firewire speed code * @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, 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. 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; } 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_ctx_payload_size(s); 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; } else { s->ctx_data.rx.seq_index = 0; s->ctx_data.rx.event_count = 0; } 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, -1, 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); /** * amdtp_domain_start - start sending packets for isoc context in the domain. * @d: the AMDTP domain. * @tx_init_skip_cycles: the number of cycles to skip processing packets at initial stage of IR * contexts. */ int amdtp_domain_start(struct amdtp_domain *d, unsigned int tx_init_skip_cycles) { 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 queue_size; struct amdtp_stream *s; 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; d->processing_cycle.tx_init_skip = tx_init_skip_cycles; // 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; list_for_each_entry(s, &d->streams, list) { unsigned int idle_irq_interval = 0; if (s->direction == AMDTP_OUT_STREAM && s == d->irq_target) { idle_irq_interval = DIV_ROUND_UP(CYCLES_PER_SECOND * events_per_period, amdtp_rate_table[d->irq_target->sfc]); } // Starts immediately but actually DMA context starts several hundred cycles later. err = amdtp_stream_start(s, s->channel, s->speed, 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);