linux/sound/firewire/digi00x/amdtp-dot.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 * amdtp-dot.c - a part of driver for Digidesign Digi 002/003 family
 *
 * Copyright (c) 2014-2015 Takashi Sakamoto
 * Copyright (C) 2012 Robin Gareus <[email protected]>
 * Copyright (C) 2012 Damien Zammit <[email protected]>
 */

#include <sound/pcm.h>
#include "digi00x.h"

#define CIP_FMT_AM …

/* 'Clock-based rate control mode' is just supported. */
#define AMDTP_FDF_AM824 …

/*
 * Nominally 3125 bytes/second, but the MIDI port's clock might be
 * 1% too slow, and the bus clock 100 ppm too fast.
 */
#define MIDI_BYTES_PER_SECOND …

/*
 * Several devices look only at the first eight data blocks.
 * In any case, this is more than enough for the MIDI data rate.
 */
#define MAX_MIDI_RX_BLOCKS …

/* 3 = MAX(DOT_MIDI_IN_PORTS, DOT_MIDI_OUT_PORTS) + 1. */
#define MAX_MIDI_PORTS …

/*
 * The double-oh-three algorithm was discovered by Robin Gareus and Damien
 * Zammit in 2012, with reverse-engineering for Digi 003 Rack.
 */
struct dot_state { … };

struct amdtp_dot { … };

/*
 * double-oh-three look up table
 *
 * @param idx index byte (audio-sample data) 0x00..0xff
 * @param off channel offset shift
 * @return salt to XOR with given data
 */
#define BYTE_PER_SAMPLE …
#define MAGIC_DOT_BYTE …
#define MAGIC_BYTE_OFF(x) …
static u8 dot_scrt(const u8 idx, const unsigned int off)
{ … }

static void dot_encode_step(struct dot_state *state, __be32 *const buffer)
{ … }

int amdtp_dot_set_parameters(struct amdtp_stream *s, unsigned int rate,
			     unsigned int pcm_channels)
{ … }

static void write_pcm_s32(struct amdtp_stream *s, struct snd_pcm_substream *pcm,
			  __be32 *buffer, unsigned int frames,
			  unsigned int pcm_frames)
{ … }

static void read_pcm_s32(struct amdtp_stream *s, struct snd_pcm_substream *pcm,
			 __be32 *buffer, unsigned int frames,
			 unsigned int pcm_frames)
{ … }

static void write_pcm_silence(struct amdtp_stream *s, __be32 *buffer,
			      unsigned int data_blocks)
{ … }

static bool midi_ratelimit_per_packet(struct amdtp_stream *s, unsigned int port)
{ … }

static inline void midi_use_bytes(struct amdtp_stream *s,
				  unsigned int port, unsigned int count)
{ … }

static void write_midi_messages(struct amdtp_stream *s, __be32 *buffer,
		unsigned int data_blocks, unsigned int data_block_counter)
{ … }

static void read_midi_messages(struct amdtp_stream *s, __be32 *buffer,
			       unsigned int data_blocks)
{ … }

int amdtp_dot_add_pcm_hw_constraints(struct amdtp_stream *s,
				     struct snd_pcm_runtime *runtime)
{ … }

void amdtp_dot_midi_trigger(struct amdtp_stream *s, unsigned int port,
			  struct snd_rawmidi_substream *midi)
{ … }

static void process_ir_ctx_payloads(struct amdtp_stream *s, const struct pkt_desc *desc,
				    unsigned int count, struct snd_pcm_substream *pcm)
{ … }

static void process_it_ctx_payloads(struct amdtp_stream *s, const struct pkt_desc *desc,
				    unsigned int count, struct snd_pcm_substream *pcm)
{ … }

int amdtp_dot_init(struct amdtp_stream *s, struct fw_unit *unit,
		 enum amdtp_stream_direction dir)
{ … }

void amdtp_dot_reset(struct amdtp_stream *s)
{ … }