summaryrefslogtreecommitdiff
path: root/sound/firewire/amdtp.c
diff options
context:
space:
mode:
Diffstat (limited to 'sound/firewire/amdtp.c')
-rw-r--r--sound/firewire/amdtp.c549
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);