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);