diff options
Diffstat (limited to 'sound/firewire/amdtp.c')
| -rw-r--r-- | sound/firewire/amdtp.c | 549 |
1 files changed, 549 insertions, 0 deletions
diff --git a/sound/firewire/amdtp.c b/sound/firewire/amdtp.c new file mode 100644 index 000000000000..09f70ee4d04a --- /dev/null +++ b/sound/firewire/amdtp.c @@ -0,0 +1,549 @@ +/* + * 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 "amdtp.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 µs */ + +#define TAG_CIP 1 + +#define CIP_EOH (1u << 31) +#define CIP_FMT_AM (0x10 << 24) +#define AMDTP_FDF_AM824 (0 << 19) +#define AMDTP_FDF_SFC_SHIFT 16 + +/* TODO: make these configurable */ +#define INTERRUPT_INTERVAL 16 +#define QUEUE_LENGTH 48 + +/** + * amdtp_out_stream_init - initialize an AMDTP output stream structure + * @s: the AMDTP output stream to initialize + * @unit: the target of the stream + * @flags: the packet transmission method to use + */ +int amdtp_out_stream_init(struct amdtp_out_stream *s, struct fw_unit *unit, + enum cip_out_flags flags) +{ + if (flags != CIP_NONBLOCKING) + return -EINVAL; + + s->unit = fw_unit_get(unit); + s->flags = flags; + s->context = ERR_PTR(-1); + mutex_init(&s->mutex); + + return 0; +} +EXPORT_SYMBOL(amdtp_out_stream_init); + +/** + * amdtp_out_stream_destroy - free stream resources + * @s: the AMDTP output stream to destroy + */ +void amdtp_out_stream_destroy(struct amdtp_out_stream *s) +{ + WARN_ON(!IS_ERR(s->context)); + mutex_destroy(&s->mutex); + fw_unit_put(s->unit); +} +EXPORT_SYMBOL(amdtp_out_stream_destroy); + +/** + * amdtp_out_stream_set_rate - set the sample rate + * @s: the AMDTP output stream to configure + * @rate: the sample rate + * + * The sample rate must be set before the stream is started, and must not be + * changed while the stream is running. + */ +void amdtp_out_stream_set_rate(struct amdtp_out_stream *s, unsigned int rate) +{ + static const struct { + unsigned int rate; + unsigned int syt_interval; + } rate_info[] = { + [CIP_SFC_32000] = { 32000, 8, }, + [CIP_SFC_44100] = { 44100, 8, }, + [CIP_SFC_48000] = { 48000, 8, }, + [CIP_SFC_88200] = { 88200, 16, }, + [CIP_SFC_96000] = { 96000, 16, }, + [CIP_SFC_176400] = { 176400, 32, }, + [CIP_SFC_192000] = { 192000, 32, }, + }; + unsigned int sfc; + + if (WARN_ON(!IS_ERR(s->context))) + return; + + for (sfc = 0; sfc < ARRAY_SIZE(rate_info); ++sfc) + if (rate_info[sfc].rate == rate) { + s->sfc = sfc; + s->syt_interval = rate_info[sfc].syt_interval; + return; + } + WARN_ON(1); +} +EXPORT_SYMBOL(amdtp_out_stream_set_rate); + +/** + * amdtp_out_stream_get_max_payload - get the stream's packet size + * @s: the AMDTP output stream + * + * This function must not be called before the stream has been configured + * with amdtp_out_stream_set_hw_params(), amdtp_out_stream_set_pcm(), and + * amdtp_out_stream_set_midi(). + */ +unsigned int amdtp_out_stream_get_max_payload(struct amdtp_out_stream *s) +{ + static const unsigned int max_data_blocks[] = { + [CIP_SFC_32000] = 4, + [CIP_SFC_44100] = 6, + [CIP_SFC_48000] = 6, + [CIP_SFC_88200] = 12, + [CIP_SFC_96000] = 12, + [CIP_SFC_176400] = 23, + [CIP_SFC_192000] = 24, + }; + + s->data_block_quadlets = s->pcm_channels; + s->data_block_quadlets += DIV_ROUND_UP(s->midi_ports, 8); + + return 8 + max_data_blocks[s->sfc] * 4 * s->data_block_quadlets; +} +EXPORT_SYMBOL(amdtp_out_stream_get_max_payload); + +static void amdtp_write_s16(struct amdtp_out_stream *s, + struct snd_pcm_substream *pcm, + __be32 *buffer, unsigned int frames); +static void amdtp_write_s32(struct amdtp_out_stream *s, + struct snd_pcm_substream *pcm, + __be32 *buffer, unsigned int frames); + +/** + * amdtp_out_stream_set_pcm_format - set the PCM format + * @s: the AMDTP output stream to configure + * @format: the format of the ALSA PCM device + * + * The sample format must be set before the stream is started, and must not be + * changed while the stream is running. + */ +void amdtp_out_stream_set_pcm_format(struct amdtp_out_stream *s, + snd_pcm_format_t format) +{ + if (WARN_ON(!IS_ERR(s->context))) + return; + + switch (format) { + default: + WARN_ON(1); + /* fall through */ + case SNDRV_PCM_FORMAT_S16: + s->transfer_samples = amdtp_write_s16; + break; + case SNDRV_PCM_FORMAT_S32: + s->transfer_samples = amdtp_write_s32; + break; + } +} +EXPORT_SYMBOL(amdtp_out_stream_set_pcm_format); + +static unsigned int calculate_data_blocks(struct amdtp_out_stream *s) +{ + unsigned int phase, data_blocks; + + 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_out_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; + + syt_offset += TRANSFER_DELAY_TICKS - TICKS_PER_CYCLE; + syt = (cycle + syt_offset / TICKS_PER_CYCLE) << 12; + syt += syt_offset % TICKS_PER_CYCLE; + + return syt & 0xffff; +} + +static void amdtp_write_s32(struct amdtp_out_stream *s, + struct snd_pcm_substream *pcm, + __be32 *buffer, unsigned int frames) +{ + struct snd_pcm_runtime *runtime = pcm->runtime; + unsigned int channels, remaining_frames, frame_step, i, c; + const u32 *src; + + channels = s->pcm_channels; + src = (void *)runtime->dma_area + + s->pcm_buffer_pointer * (runtime->frame_bits / 8); + remaining_frames = runtime->buffer_size - s->pcm_buffer_pointer; + frame_step = s->data_block_quadlets - channels; + + for (i = 0; i < frames; ++i) { + for (c = 0; c < channels; ++c) { + *buffer = cpu_to_be32((*src >> 8) | 0x40000000); + src++; + buffer++; + } + buffer += frame_step; + if (--remaining_frames == 0) + src = (void *)runtime->dma_area; + } +} + +static void amdtp_write_s16(struct amdtp_out_stream *s, + struct snd_pcm_substream *pcm, + __be32 *buffer, unsigned int frames) +{ + struct snd_pcm_runtime *runtime = pcm->runtime; + unsigned int channels, remaining_frames, frame_step, i, c; + const u16 *src; + + channels = s->pcm_channels; + src = (void *)runtime->dma_area + + s->pcm_buffer_pointer * (runtime->frame_bits / 8); + remaining_frames = runtime->buffer_size - s->pcm_buffer_pointer; + frame_step = s->data_block_quadlets - channels; + + for (i = 0; i < frames; ++i) { + for (c = 0; c < channels; ++c) { + *buffer = cpu_to_be32((*src << 8) | 0x40000000); + src++; + buffer++; + } + buffer += frame_step; + if (--remaining_frames == 0) + src = (void *)runtime->dma_area; + } +} + +static void amdtp_fill_pcm_silence(struct amdtp_out_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[c] = cpu_to_be32(0x40000000); + buffer += s->data_block_quadlets; + } +} + +static void amdtp_fill_midi(struct amdtp_out_stream *s, + __be32 *buffer, unsigned int frames) +{ + unsigned int i; + + for (i = 0; i < frames; ++i) + buffer[s->pcm_channels + i * s->data_block_quadlets] = + cpu_to_be32(0x80000000); +} + +static void queue_out_packet(struct amdtp_out_stream *s, unsigned int cycle) +{ + __be32 *buffer; + unsigned int data_blocks, syt, ptr; + struct snd_pcm_substream *pcm; + struct fw_iso_packet packet; + int err; + + data_blocks = calculate_data_blocks(s); + syt = calculate_syt(s, cycle); + + buffer = s->buffer.packets[s->packet_counter].buffer; + buffer[0] = cpu_to_be32(ACCESS_ONCE(s->source_node_id_field) | + (s->data_block_quadlets << 16) | + s->data_block_counter); + buffer[1] = cpu_to_be32(CIP_EOH | CIP_FMT_AM | AMDTP_FDF_AM824 | + (s->sfc << AMDTP_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; + + packet.payload_length = 8 + data_blocks * 4 * s->data_block_quadlets; + packet.interrupt = IS_ALIGNED(s->packet_counter + 1, + INTERRUPT_INTERVAL); + packet.skip = 0; + packet.tag = TAG_CIP; + packet.sy = 0; + packet.header_length = 0; + + err = fw_iso_context_queue(s->context, &packet, &s->buffer.iso_buffer, + s->buffer.packets[s->packet_counter].offset); + if (err < 0) + dev_err(&s->unit->device, "queueing error: %d\n", err); + + if (++s->packet_counter >= QUEUE_LENGTH) + s->packet_counter = 0; + + if (pcm) { + ptr = s->pcm_buffer_pointer + data_blocks; + if (ptr >= pcm->runtime->buffer_size) + ptr -= pcm->runtime->buffer_size; + ACCESS_ONCE(s->pcm_buffer_pointer) = ptr; + + s->pcm_period_pointer += data_blocks; + if (s->pcm_period_pointer >= pcm->runtime->period_size) { + s->pcm_period_pointer -= pcm->runtime->period_size; + snd_pcm_period_elapsed(pcm); + } + } +} + +static void out_packet_callback(struct fw_iso_context *context, u32 cycle, + size_t header_length, void *header, void *data) +{ + struct amdtp_out_stream *s = data; + unsigned int i, 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) + queue_out_packet(s, ++cycle); +} + +static int queue_initial_skip_packets(struct amdtp_out_stream *s) +{ + struct fw_iso_packet skip_packet = { + .skip = 1, + }; + unsigned int i; + int err; + + for (i = 0; i < QUEUE_LENGTH; ++i) { + skip_packet.interrupt = IS_ALIGNED(s->packet_counter + 1, + INTERRUPT_INTERVAL); + err = fw_iso_context_queue(s->context, &skip_packet, NULL, 0); + if (err < 0) + return err; + if (++s->packet_counter >= QUEUE_LENGTH) + s->packet_counter = 0; + } + + return 0; +} + +/** + * amdtp_out_stream_start - start sending packets + * @s: the AMDTP output 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_out_stream_set_hw_params(), amdtp_out_stream_set_pcm(), and + * amdtp_out_stream_set_midi(); and it must be started before any + * PCM or MIDI device can be started. + */ +int amdtp_out_stream_start(struct amdtp_out_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 }, + }; + int err; + + mutex_lock(&s->mutex); + + if (WARN_ON(!IS_ERR(s->context) || + (!s->pcm_channels && !s->midi_ports))) { + err = -EBADFD; + goto err_unlock; + } + + 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; + + err = iso_packets_buffer_init(&s->buffer, s->unit, QUEUE_LENGTH, + amdtp_out_stream_get_max_payload(s), + DMA_TO_DEVICE); + if (err < 0) + goto err_unlock; + + s->context = fw_iso_context_create(fw_parent_device(s->unit)->card, + FW_ISO_CONTEXT_TRANSMIT, + channel, speed, 0, + out_packet_callback, s); + if (IS_ERR(s->context)) { + err = PTR_ERR(s->context); + if (err == -EBUSY) + dev_err(&s->unit->device, + "no free output stream on this controller\n"); + goto err_buffer; + } + + amdtp_out_stream_update(s); + + s->packet_counter = 0; + s->data_block_counter = 0; + err = queue_initial_skip_packets(s); + if (err < 0) + goto err_context; + + err = fw_iso_context_start(s->context, -1, 0, 0); + 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_out_stream_start); + +/** + * amdtp_out_stream_update - update the stream after a bus reset + * @s: the AMDTP output stream + */ +void amdtp_out_stream_update(struct amdtp_out_stream *s) +{ + ACCESS_ONCE(s->source_node_id_field) = + (fw_parent_device(s->unit)->card->node_id & 0x3f) << 24; +} +EXPORT_SYMBOL(amdtp_out_stream_update); + +/** + * amdtp_out_stream_stop - stop sending packets + * @s: the AMDTP output stream to stop + * + * All PCM and MIDI devices of the stream must be stopped before the stream + * itself can be stopped. + */ +void amdtp_out_stream_stop(struct amdtp_out_stream *s) +{ + mutex_lock(&s->mutex); + + if (IS_ERR(s->context)) { + mutex_unlock(&s->mutex); + return; + } + + 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); + + mutex_unlock(&s->mutex); +} +EXPORT_SYMBOL(amdtp_out_stream_stop); + +/** + * amdtp_out_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_out_stream_pcm_abort(struct amdtp_out_stream *s) +{ + struct snd_pcm_substream *pcm; + + pcm = ACCESS_ONCE(s->pcm); + if (pcm) { + snd_pcm_stream_lock_irq(pcm); + if (snd_pcm_running(pcm)) + snd_pcm_stop(pcm, SNDRV_PCM_STATE_XRUN); + snd_pcm_stream_unlock_irq(pcm); + } +} +EXPORT_SYMBOL(amdtp_out_stream_pcm_abort); |