--- /dev/null
+/*
+ * amdtp-motu.c - a part of driver for MOTU FireWire series
+ *
+ * Copyright (c) 2015-2017 Takashi Sakamoto <o-takashi@sakamocchi.jp>
+ *
+ * Licensed under the terms of the GNU General Public License, version 2.
+ */
+
+#include <linux/slab.h>
+#include <sound/pcm.h>
+#include "motu.h"
+
+#define CIP_FMT_MOTU 0x02
+#define MOTU_FDF_AM824 0x22
+
+struct amdtp_motu {
+ /* For timestamp processing. */
+ unsigned int quotient_ticks_per_event;
+ unsigned int remainder_ticks_per_event;
+ unsigned int next_ticks;
+ unsigned int next_accumulated;
+ unsigned int next_cycles;
+ unsigned int next_seconds;
+
+ unsigned int pcm_chunks;
+ unsigned int pcm_byte_offset;
+};
+
+int amdtp_motu_set_parameters(struct amdtp_stream *s, unsigned int rate,
+ struct snd_motu_packet_format *formats)
+{
+ static const struct {
+ unsigned int quotient_ticks_per_event;
+ unsigned int remainder_ticks_per_event;
+ } params[] = {
+ [CIP_SFC_44100] = { 557, 123 },
+ [CIP_SFC_48000] = { 512, 0 },
+ [CIP_SFC_88200] = { 278, 282 },
+ [CIP_SFC_96000] = { 256, 0 },
+ [CIP_SFC_176400] = { 139, 141 },
+ [CIP_SFC_192000] = { 128, 0 },
+ };
+ struct amdtp_motu *p = s->protocol;
+ unsigned int pcm_chunks, data_chunks, data_block_quadlets;
+ unsigned int delay;
+ unsigned int mode;
+ int i, err;
+
+ if (amdtp_stream_running(s))
+ return -EBUSY;
+
+ for (i = 0; i < ARRAY_SIZE(snd_motu_clock_rates); ++i) {
+ if (snd_motu_clock_rates[i] == rate) {
+ mode = i >> 1;
+ break;
+ }
+ }
+ if (i == ARRAY_SIZE(snd_motu_clock_rates))
+ return -EINVAL;
+
+ pcm_chunks = formats->fixed_part_pcm_chunks[mode] +
+ formats->differed_part_pcm_chunks[mode];
+ data_chunks = formats->msg_chunks + pcm_chunks;
+
+ /*
+ * Each data block includes SPH in its head. Data chunks follow with
+ * 3 byte alignment. Padding follows with zero to conform to quadlet
+ * alignment.
+ */
+ data_block_quadlets = 1 + DIV_ROUND_UP(data_chunks * 3, 4);
+
+ err = amdtp_stream_set_parameters(s, rate, data_block_quadlets);
+ if (err < 0)
+ return err;
+
+ p->pcm_chunks = pcm_chunks;
+ p->pcm_byte_offset = formats->pcm_byte_offset;
+
+ /* IEEE 1394 bus requires. */
+ delay = 0x2e00;
+
+ /* For no-data or empty packets to adjust PCM sampling frequency. */
+ delay += 8000 * 3072 * s->syt_interval / rate;
+
+ p->next_seconds = 0;
+ p->next_cycles = delay / 3072;
+ p->quotient_ticks_per_event = params[s->sfc].quotient_ticks_per_event;
+ p->remainder_ticks_per_event = params[s->sfc].remainder_ticks_per_event;
+ p->next_ticks = delay % 3072;
+ p->next_accumulated = 0;
+
+ return 0;
+}
+
+static void read_pcm_s32(struct amdtp_stream *s,
+ struct snd_pcm_runtime *runtime,
+ __be32 *buffer, unsigned int data_blocks)
+{
+ struct amdtp_motu *p = s->protocol;
+ unsigned int channels, remaining_frames, i, c;
+ u8 *byte;
+ u32 *dst;
+
+ channels = p->pcm_chunks;
+ dst = (void *)runtime->dma_area +
+ frames_to_bytes(runtime, s->pcm_buffer_pointer);
+ remaining_frames = runtime->buffer_size - s->pcm_buffer_pointer;
+
+ for (i = 0; i < data_blocks; ++i) {
+ byte = (u8 *)buffer + p->pcm_byte_offset;
+
+ for (c = 0; c < channels; ++c) {
+ *dst = (byte[0] << 24) | (byte[1] << 16) | byte[2];
+ byte += 3;
+ dst++;
+ }
+ buffer += s->data_block_quadlets;
+ if (--remaining_frames == 0)
+ dst = (void *)runtime->dma_area;
+ }
+}
+
+static void write_pcm_s32(struct amdtp_stream *s,
+ struct snd_pcm_runtime *runtime,
+ __be32 *buffer, unsigned int data_blocks)
+{
+ struct amdtp_motu *p = s->protocol;
+ unsigned int channels, remaining_frames, i, c;
+ u8 *byte;
+ const u32 *src;
+
+ channels = p->pcm_chunks;
+ src = (void *)runtime->dma_area +
+ frames_to_bytes(runtime, s->pcm_buffer_pointer);
+ remaining_frames = runtime->buffer_size - s->pcm_buffer_pointer;
+
+ for (i = 0; i < data_blocks; ++i) {
+ byte = (u8 *)buffer + p->pcm_byte_offset;
+
+ for (c = 0; c < channels; ++c) {
+ byte[0] = (*src >> 24) & 0xff;
+ byte[1] = (*src >> 16) & 0xff;
+ byte[2] = (*src >> 8) & 0xff;
+ byte += 3;
+ src++;
+ }
+
+ buffer += s->data_block_quadlets;
+ if (--remaining_frames == 0)
+ src = (void *)runtime->dma_area;
+ }
+}
+
+static void write_pcm_silence(struct amdtp_stream *s, __be32 *buffer,
+ unsigned int data_blocks)
+{
+ struct amdtp_motu *p = s->protocol;
+ unsigned int channels, i, c;
+ u8 *byte;
+
+ channels = p->pcm_chunks;
+
+ for (i = 0; i < data_blocks; ++i) {
+ byte = (u8 *)buffer + p->pcm_byte_offset;
+
+ for (c = 0; c < channels; ++c) {
+ byte[0] = 0;
+ byte[1] = 0;
+ byte[2] = 0;
+ byte += 3;
+ }
+
+ buffer += s->data_block_quadlets;
+ }
+}
+
+int amdtp_motu_add_pcm_hw_constraints(struct amdtp_stream *s,
+ struct snd_pcm_runtime *runtime)
+{
+ int err;
+
+ /* TODO: how to set an constraint for exactly 24bit PCM sample? */
+ err = snd_pcm_hw_constraint_msbits(runtime, 0, 32, 24);
+ if (err < 0)
+ return err;
+
+ return amdtp_stream_add_pcm_hw_constraints(s, runtime);
+}
+
+static unsigned int process_tx_data_blocks(struct amdtp_stream *s,
+ __be32 *buffer, unsigned int data_blocks,
+ unsigned int *syt)
+{
+ struct snd_pcm_substream *pcm;
+
+ pcm = ACCESS_ONCE(s->pcm);
+ if (data_blocks > 0 && pcm)
+ read_pcm_s32(s, pcm->runtime, buffer, data_blocks);
+
+ return data_blocks;
+}
+
+static inline void compute_next_elapse_from_start(struct amdtp_motu *p)
+{
+ p->next_accumulated += p->remainder_ticks_per_event;
+ if (p->next_accumulated >= 441) {
+ p->next_accumulated -= 441;
+ p->next_ticks++;
+ }
+
+ p->next_ticks += p->quotient_ticks_per_event;
+ if (p->next_ticks >= 3072) {
+ p->next_ticks -= 3072;
+ p->next_cycles++;
+ }
+
+ if (p->next_cycles >= 8000) {
+ p->next_cycles -= 8000;
+ p->next_seconds++;
+ }
+
+ if (p->next_seconds >= 128)
+ p->next_seconds -= 128;
+}
+
+static void write_sph(struct amdtp_stream *s, __be32 *buffer,
+ unsigned int data_blocks)
+{
+ struct amdtp_motu *p = s->protocol;
+ unsigned int next_cycles;
+ unsigned int i;
+ u32 sph;
+
+ for (i = 0; i < data_blocks; i++) {
+ next_cycles = (s->start_cycle + p->next_cycles) % 8000;
+ sph = ((next_cycles << 12) | p->next_ticks) & 0x01ffffff;
+ *buffer = cpu_to_be32(sph);
+
+ compute_next_elapse_from_start(p);
+
+ buffer += s->data_block_quadlets;
+ }
+}
+
+static unsigned int process_rx_data_blocks(struct amdtp_stream *s,
+ __be32 *buffer, unsigned int data_blocks,
+ unsigned int *syt)
+{
+ struct snd_pcm_substream *pcm;
+
+ /* Not used. */
+ *syt = 0xffff;
+
+ /* TODO: how to interact control messages between userspace? */
+
+ pcm = ACCESS_ONCE(s->pcm);
+ if (pcm)
+ write_pcm_s32(s, pcm->runtime, buffer, data_blocks);
+ else
+ write_pcm_silence(s, buffer, data_blocks);
+
+ write_sph(s, buffer, data_blocks);
+
+ return data_blocks;
+}
+
+int amdtp_motu_init(struct amdtp_stream *s, struct fw_unit *unit,
+ enum amdtp_stream_direction dir,
+ const struct snd_motu_protocol *const protocol)
+{
+ amdtp_stream_process_data_blocks_t process_data_blocks;
+ int fmt = CIP_FMT_MOTU;
+ int flags = CIP_BLOCKING;
+ int err;
+
+ if (dir == AMDTP_IN_STREAM) {
+ process_data_blocks = process_tx_data_blocks;
+ } else {
+ process_data_blocks = process_rx_data_blocks;
+ flags |= CIP_DBC_IS_END_EVENT;
+ }
+
+ err = amdtp_stream_init(s, unit, dir, flags, fmt, process_data_blocks,
+ sizeof(struct amdtp_motu));
+ if (err < 0)
+ return err;
+
+ s->sph = 1;
+ s->fdf = MOTU_FDF_AM824;
+
+ return 0;
+}
projects / nvme.git / commitdiff