[linux-2.6-block.git] / 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 <robin@gareus.org>
 * Copyright (C) 2012 Damien Zammit <damien@zamaudio.com>
 */

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

#define CIP_FMT_AM		0x10

/* 'Clock-based rate control mode' is just supported. */
#define AMDTP_FDF_AM824		0x00

/*
 * 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	3093

/*
 * 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	8

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

/*
 * 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 {
	u8 carry;
	u8 idx;
	unsigned int off;
};

struct amdtp_dot {
	unsigned int pcm_channels;
	struct dot_state state;

	struct snd_rawmidi_substream *midi[MAX_MIDI_PORTS];
	int midi_fifo_used[MAX_MIDI_PORTS];
	int midi_fifo_limit;
};

/*
 * 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 (4)
#define MAGIC_DOT_BYTE (2)
#define MAGIC_BYTE_OFF(x) (((x) * BYTE_PER_SAMPLE) + MAGIC_DOT_BYTE)
static u8 dot_scrt(const u8 idx, const unsigned int off)
{
	/*
	 * the length of the added pattern only depends on the lower nibble
	 * of the last non-zero data
	 */
	static const u8 len[16] = {0, 1, 3, 5, 7, 9, 11, 13, 14,
				   12, 10, 8, 6, 4, 2, 0};

	/*
	 * the lower nibble of the salt. Interleaved sequence.
	 * this is walked backwards according to len[]
	 */
	static const u8 nib[15] = {0x8, 0x7, 0x9, 0x6, 0xa, 0x5, 0xb, 0x4,
				   0xc, 0x3, 0xd, 0x2, 0xe, 0x1, 0xf};

	/* circular list for the salt's hi nibble. */
	static const u8 hir[15] = {0x0, 0x6, 0xf, 0x8, 0x7, 0x5, 0x3, 0x4,
				   0xc, 0xd, 0xe, 0x1, 0x2, 0xb, 0xa};

	/*
	 * start offset for upper nibble mapping.
	 * note: 9 is /special/. In the case where the high nibble == 0x9,
	 * hir[] is not used and - coincidentally - the salt's hi nibble is
	 * 0x09 regardless of the offset.
	 */
	static const u8 hio[16] = {0, 11, 12, 6, 7, 5, 1, 4,
				   3, 0x00, 14, 13, 8, 9, 10, 2};

	const u8 ln = idx & 0xf;
	const u8 hn = (idx >> 4) & 0xf;
	const u8 hr = (hn == 0x9) ? 0x9 : hir[(hio[hn] + off) % 15];

	if (len[ln] < off)
		return 0x00;

	return ((nib[14 + off - len[ln]]) | (hr << 4));
}

static void dot_encode_step(struct dot_state *state, __be32 *const buffer)
{
	u8 * const data = (u8 *) buffer;

	if (data[MAGIC_DOT_BYTE] != 0x00) {
		state->off = 0;
		state->idx = data[MAGIC_DOT_BYTE] ^ state->carry;
	}
	data[MAGIC_DOT_BYTE] ^= state->carry;
	state->carry = dot_scrt(state->idx, ++(state->off));
}

int amdtp_dot_set_parameters(struct amdtp_stream *s, unsigned int rate,
			     unsigned int pcm_channels)
{
	struct amdtp_dot *p = s->protocol;
	int err;

	if (amdtp_stream_running(s))
		return -EBUSY;

	/*
	 * A first data channel is for MIDI messages, the rest is Multi Bit
	 * Linear Audio data channel.
	 */
	err = amdtp_stream_set_parameters(s, rate, pcm_channels + 1);
	if (err < 0)
		return err;

	s->ctx_data.rx.fdf = AMDTP_FDF_AM824 | s->sfc;

	p->pcm_channels = pcm_channels;

	/*
	 * We do not know the actual MIDI FIFO size of most devices.  Just
	 * assume two bytes, i.e., one byte can be received over the bus while
	 * the previous one is transmitted over MIDI.
	 * (The value here is adjusted for midi_ratelimit_per_packet().)
	 */
	p->midi_fifo_limit = rate - MIDI_BYTES_PER_SECOND * s->syt_interval + 1;

	return 0;
}

static void write_pcm_s32(struct amdtp_stream *s, struct snd_pcm_substream *pcm,
			  __be32 *buffer, unsigned int frames,
			  unsigned int pcm_frames)
{
	struct amdtp_dot *p = s->protocol;
	unsigned int channels = p->pcm_channels;
	struct snd_pcm_runtime *runtime = pcm->runtime;
	unsigned int pcm_buffer_pointer;
	int remaining_frames;
	const u32 *src;
	int i, c;

	pcm_buffer_pointer = s->pcm_buffer_pointer + pcm_frames;
	pcm_buffer_pointer %= runtime->buffer_size;

	src = (void *)runtime->dma_area +
				frames_to_bytes(runtime, pcm_buffer_pointer);
	remaining_frames = runtime->buffer_size - pcm_buffer_pointer;

	buffer++;
	for (i = 0; i < frames; ++i) {
		for (c = 0; c < channels; ++c) {
			buffer[c] = cpu_to_be32((*src >> 8) | 0x40000000);
			dot_encode_step(&p->state, &buffer[c]);
			src++;
		}
		buffer += s->data_block_quadlets;
		if (--remaining_frames == 0)
			src = (void *)runtime->dma_area;
	}
}

static void read_pcm_s32(struct amdtp_stream *s, struct snd_pcm_substream *pcm,
			 __be32 *buffer, unsigned int frames,
			 unsigned int pcm_frames)
{
	struct amdtp_dot *p = s->protocol;
	unsigned int channels = p->pcm_channels;
	struct snd_pcm_runtime *runtime = pcm->runtime;
	unsigned int pcm_buffer_pointer;
	int remaining_frames;
	u32 *dst;
	int i, c;

	pcm_buffer_pointer = s->pcm_buffer_pointer + pcm_frames;
	pcm_buffer_pointer %= runtime->buffer_size;

	dst  = (void *)runtime->dma_area +
				frames_to_bytes(runtime, pcm_buffer_pointer);
	remaining_frames = runtime->buffer_size - pcm_buffer_pointer;

	buffer++;
	for (i = 0; i < frames; ++i) {
		for (c = 0; c < channels; ++c) {
			*dst = be32_to_cpu(buffer[c]) << 8;
			dst++;
		}
		buffer += s->data_block_quadlets;
		if (--remaining_frames == 0)
			dst = (void *)runtime->dma_area;
	}
}

static void write_pcm_silence(struct amdtp_stream *s, __be32 *buffer,
			      unsigned int data_blocks)
{
	struct amdtp_dot *p = s->protocol;
	unsigned int channels, i, c;

	channels = p->pcm_channels;

	buffer++;
	for (i = 0; i < data_blocks; ++i) {
		for (c = 0; c < channels; ++c)
			buffer[c] = cpu_to_be32(0x40000000);
		buffer += s->data_block_quadlets;
	}
}

static bool midi_ratelimit_per_packet(struct amdtp_stream *s, unsigned int port)
{
	struct amdtp_dot *p = s->protocol;
	int used;

	used = p->midi_fifo_used[port];
	if (used == 0)
		return true;

	used -= MIDI_BYTES_PER_SECOND * s->syt_interval;
	used = max(used, 0);
	p->midi_fifo_used[port] = used;

	return used < p->midi_fifo_limit;
}

static inline void midi_use_bytes(struct amdtp_stream *s,
				  unsigned int port, unsigned int count)
{
	struct amdtp_dot *p = s->protocol;

	p->midi_fifo_used[port] += amdtp_rate_table[s->sfc] * count;
}

static void write_midi_messages(struct amdtp_stream *s, __be32 *buffer,
		unsigned int data_blocks, unsigned int data_block_counter)
{
	struct amdtp_dot *p = s->protocol;
	unsigned int f, port;
	int len;
	u8 *b;

	for (f = 0; f < data_blocks; f++) {
		port = (data_block_counter + f) % 8;
		b = (u8 *)&buffer[0];

		len = 0;
		if (port < MAX_MIDI_PORTS &&
		    midi_ratelimit_per_packet(s, port) &&
		    p->midi[port] != NULL)
			len = snd_rawmidi_transmit(p->midi[port], b + 1, 2);

		if (len > 0) {
			/*
			 * Upper 4 bits of LSB represent port number.
			 * - 0000b: physical MIDI port 1.
			 * - 0010b: physical MIDI port 2.
			 * - 1110b: console MIDI port.
			 */
			if (port == 2)
				b[3] = 0xe0;
			else if (port == 1)
				b[3] = 0x20;
			else
				b[3] = 0x00;
			b[3] |= len;
			midi_use_bytes(s, port, len);
		} else {
			b[1] = 0;
			b[2] = 0;
			b[3] = 0;
		}
		b[0] = 0x80;

		buffer += s->data_block_quadlets;
	}
}

static void read_midi_messages(struct amdtp_stream *s, __be32 *buffer,
			       unsigned int data_blocks)
{
	struct amdtp_dot *p = s->protocol;
	unsigned int f, port, len;
	u8 *b;

	for (f = 0; f < data_blocks; f++) {
		b = (u8 *)&buffer[0];

		len = b[3] & 0x0f;
		if (len > 0) {
			/*
			 * Upper 4 bits of LSB represent port number.
			 * - 0000b: physical MIDI port 1. Use port 0.
			 * - 1110b: console MIDI port. Use port 2.
			 */
			if (b[3] >> 4 > 0)
				port = 2;
			else
				port = 0;

			if (port < MAX_MIDI_PORTS && p->midi[port])
				snd_rawmidi_receive(p->midi[port], b + 1, len);
		}

		buffer += s->data_block_quadlets;
	}
}

int amdtp_dot_add_pcm_hw_constraints(struct amdtp_stream *s,
				     struct snd_pcm_runtime *runtime)
{
	int err;

	/* This protocol delivers 24 bit data in 32bit data channel. */
	err = snd_pcm_hw_constraint_msbits(runtime, 0, 32, 24);
	if (err < 0)
		return err;

	return amdtp_stream_add_pcm_hw_constraints(s, runtime);
}

void amdtp_dot_midi_trigger(struct amdtp_stream *s, unsigned int port,
			  struct snd_rawmidi_substream *midi)
{
	struct amdtp_dot *p = s->protocol;

	if (port < MAX_MIDI_PORTS)
		WRITE_ONCE(p->midi[port], midi);
}

static unsigned int process_tx_data_blocks(struct amdtp_stream *s,
					   const struct pkt_desc *desc,
					   struct snd_pcm_substream *pcm)
{
	unsigned int pcm_frames = 0;

	if (pcm) {
		read_pcm_s32(s, pcm, desc->ctx_payload, desc->data_blocks,
			     pcm_frames);
		pcm_frames = desc->data_blocks;
	}

	read_midi_messages(s, desc->ctx_payload, desc->data_blocks);

	return pcm_frames;
}

static unsigned int process_rx_data_blocks(struct amdtp_stream *s,
					   const struct pkt_desc *desc,
					   struct snd_pcm_substream *pcm)
{
	unsigned int pcm_frames = 0;

	if (pcm) {
		write_pcm_s32(s, pcm, desc->ctx_payload, desc->data_blocks,
			      pcm_frames);
		pcm_frames = desc->data_blocks;
	} else {
		write_pcm_silence(s, desc->ctx_payload, desc->data_blocks);
	}

	write_midi_messages(s, desc->ctx_payload, desc->data_blocks,
			    desc->data_block_counter);

	return pcm_frames;
}

int amdtp_dot_init(struct amdtp_stream *s, struct fw_unit *unit,
		 enum amdtp_stream_direction dir)
{
	amdtp_stream_process_data_blocks_t process_data_blocks;
	enum cip_flags flags;

	/* Use different mode between incoming/outgoing. */
	if (dir == AMDTP_IN_STREAM) {
		flags = CIP_NONBLOCKING;
		process_data_blocks = process_tx_data_blocks;
	} else {
		flags = CIP_BLOCKING;
		process_data_blocks = process_rx_data_blocks;
	}

	return amdtp_stream_init(s, unit, dir, flags, CIP_FMT_AM,
				 process_data_blocks, sizeof(struct amdtp_dot));
}

void amdtp_dot_reset(struct amdtp_stream *s)
{
	struct amdtp_dot *p = s->protocol;

	p->state.carry = 0x00;
	p->state.idx = 0x00;
	p->state.off = 0;
}
Commit	Line	Data
da607e19	1	// SPDX-License-Identifier: GPL-2.0-only
163ae6f3 TS	2	/*
	3	* amdtp-dot.c - a part of driver for Digidesign Digi 002/003 family
	4	*
	5	* Copyright (c) 2014-2015 Takashi Sakamoto
	6	* Copyright (C) 2012 Robin Gareus <robin@gareus.org>
	7	* Copyright (C) 2012 Damien Zammit <damien@zamaudio.com>
163ae6f3 TS	8	*/
	9
	10	#include <sound/pcm.h>
	11	#include "digi00x.h"
	12
	13	#define CIP_FMT_AM 0x10
	14
	15	/* 'Clock-based rate control mode' is just supported. */
	16	#define AMDTP_FDF_AM824 0x00
	17
9dc5d31c TS	18	/*
	19	* Nominally 3125 bytes/second, but the MIDI port's clock might be
	20	* 1% too slow, and the bus clock 100 ppm too fast.
	21	*/
	22	#define MIDI_BYTES_PER_SECOND 3093
	23
	24	/*
	25	* Several devices look only at the first eight data blocks.
	26	* In any case, this is more than enough for the MIDI data rate.
	27	*/
	28	#define MAX_MIDI_RX_BLOCKS 8
	29
8820a4cf TS	30	/* 3 = MAX(DOT_MIDI_IN_PORTS, DOT_MIDI_OUT_PORTS) + 1. */
	31	#define MAX_MIDI_PORTS 3
	32
163ae6f3 TS	33	/*
	34	* The double-oh-three algorithm was discovered by Robin Gareus and Damien
	35	* Zammit in 2012, with reverse-engineering for Digi 003 Rack.
	36	*/
	37	struct dot_state {
17385a38 TS	38	u8 carry;
17385a38 TS	39	u8 idx;
163ae6f3 TS	40	unsigned int off;
	41	};
	42
	43	struct amdtp_dot {
	44	unsigned int pcm_channels;
	45	struct dot_state state;
	46
8820a4cf TS	47	struct snd_rawmidi_substream *midi[MAX_MIDI_PORTS];
8820a4cf TS	48	int midi_fifo_used[MAX_MIDI_PORTS];
9dc5d31c	49	int midi_fifo_limit;
163ae6f3 TS	50	};
	51
	52	/*
	53	* double-oh-three look up table
	54	*
	55	* @param idx index byte (audio-sample data) 0x00..0xff
	56	* @param off channel offset shift
	57	* @return salt to XOR with given data
	58	*/
	59	#define BYTE_PER_SAMPLE (4)
	60	#define MAGIC_DOT_BYTE (2)
	61	#define MAGIC_BYTE_OFF(x) (((x) * BYTE_PER_SAMPLE) + MAGIC_DOT_BYTE)
b8cb3750	62	static u8 dot_scrt(const u8 idx, const unsigned int off)
163ae6f3 TS	63	{
	64	/*
	65	* the length of the added pattern only depends on the lower nibble
	66	* of the last non-zero data
	67	*/
17385a38 TS	68	static const u8 len[16] = {0, 1, 3, 5, 7, 9, 11, 13, 14,
17385a38 TS	69	12, 10, 8, 6, 4, 2, 0};
163ae6f3 TS	70
	71	/*
	72	* the lower nibble of the salt. Interleaved sequence.
	73	* this is walked backwards according to len[]
	74	*/
17385a38 TS	75	static const u8 nib[15] = {0x8, 0x7, 0x9, 0x6, 0xa, 0x5, 0xb, 0x4,
17385a38 TS	76	0xc, 0x3, 0xd, 0x2, 0xe, 0x1, 0xf};
163ae6f3 TS	77
163ae6f3 TS	78	/* circular list for the salt's hi nibble. */
17385a38 TS	79	static const u8 hir[15] = {0x0, 0x6, 0xf, 0x8, 0x7, 0x5, 0x3, 0x4,
17385a38 TS	80	0xc, 0xd, 0xe, 0x1, 0x2, 0xb, 0xa};
163ae6f3 TS	81
	82	/*
	83	* start offset for upper nibble mapping.
	84	* note: 9 is /special/. In the case where the high nibble == 0x9,
	85	* hir[] is not used and - coincidentally - the salt's hi nibble is
	86	* 0x09 regardless of the offset.
	87	*/
17385a38 TS	88	static const u8 hio[16] = {0, 11, 12, 6, 7, 5, 1, 4,
17385a38 TS	89	3, 0x00, 14, 13, 8, 9, 10, 2};
163ae6f3	90
17385a38 TS	91	const u8 ln = idx & 0xf;
	92	const u8 hn = (idx >> 4) & 0xf;
	93	const u8 hr = (hn == 0x9) ? 0x9 : hir[(hio[hn] + off) % 15];
163ae6f3 TS	94
	95	if (len[ln] < off)
	96	return 0x00;
	97
	98	return ((nib[14 + off - len[ln]]) \| (hr << 4));
	99	}
	100
	101	static void dot_encode_step(struct dot_state state, __be32 const buffer)
	102	{
17385a38	103	u8 * const data = (u8 *) buffer;
163ae6f3 TS	104
	105	if (data[MAGIC_DOT_BYTE] != 0x00) {
	106	state->off = 0;
	107	state->idx = data[MAGIC_DOT_BYTE] ^ state->carry;
	108	}
	109	data[MAGIC_DOT_BYTE] ^= state->carry;
	110	state->carry = dot_scrt(state->idx, ++(state->off));
	111	}
	112
	113	int amdtp_dot_set_parameters(struct amdtp_stream *s, unsigned int rate,
9dc5d31c	114	unsigned int pcm_channels)
163ae6f3 TS	115	{
	116	struct amdtp_dot *p = s->protocol;
	117	int err;
	118
	119	if (amdtp_stream_running(s))
	120	return -EBUSY;
	121
	122	/*
8820a4cf TS	123	* A first data channel is for MIDI messages, the rest is Multi Bit
8820a4cf TS	124	* Linear Audio data channel.
163ae6f3 TS	125	*/
	126	err = amdtp_stream_set_parameters(s, rate, pcm_channels + 1);
	127	if (err < 0)
	128	return err;
	129
d3d10a4a	130	s->ctx_data.rx.fdf = AMDTP_FDF_AM824 \| s->sfc;
163ae6f3 TS	131
163ae6f3 TS	132	p->pcm_channels = pcm_channels;
9dc5d31c	133
9dc5d31c TS	134	/*
	135	* We do not know the actual MIDI FIFO size of most devices. Just
	136	* assume two bytes, i.e., one byte can be received over the bus while
	137	* the previous one is transmitted over MIDI.
	138	* (The value here is adjusted for midi_ratelimit_per_packet().)
	139	*/
	140	p->midi_fifo_limit = rate - MIDI_BYTES_PER_SECOND * s->syt_interval + 1;
163ae6f3 TS	141
	142	return 0;
	143	}
	144
	145	static void write_pcm_s32(struct amdtp_stream s, struct snd_pcm_substream pcm,
bb473966 TS	146	__be32 *buffer, unsigned int frames,
bb473966 TS	147	unsigned int pcm_frames)
163ae6f3 TS	148	{
163ae6f3 TS	149	struct amdtp_dot *p = s->protocol;
bb473966	150	unsigned int channels = p->pcm_channels;
163ae6f3	151	struct snd_pcm_runtime *runtime = pcm->runtime;
bb473966 TS	152	unsigned int pcm_buffer_pointer;
bb473966 TS	153	int remaining_frames;
163ae6f3	154	const u32 *src;
bb473966 TS	155	int i, c;
	156
	157	pcm_buffer_pointer = s->pcm_buffer_pointer + pcm_frames;
	158	pcm_buffer_pointer %= runtime->buffer_size;
163ae6f3	159
163ae6f3	160	src = (void *)runtime->dma_area +
bb473966 TS	161	frames_to_bytes(runtime, pcm_buffer_pointer);
bb473966 TS	162	remaining_frames = runtime->buffer_size - pcm_buffer_pointer;
163ae6f3 TS	163
	164	buffer++;
	165	for (i = 0; i < frames; ++i) {
	166	for (c = 0; c < channels; ++c) {
	167	buffer[c] = cpu_to_be32((*src >> 8) \| 0x40000000);
	168	dot_encode_step(&p->state, &buffer[c]);
	169	src++;
	170	}
	171	buffer += s->data_block_quadlets;
	172	if (--remaining_frames == 0)
	173	src = (void *)runtime->dma_area;
	174	}
	175	}
	176
163ae6f3	177	static void read_pcm_s32(struct amdtp_stream s, struct snd_pcm_substream pcm,
bb473966 TS	178	__be32 *buffer, unsigned int frames,
bb473966 TS	179	unsigned int pcm_frames)
163ae6f3 TS	180	{
163ae6f3 TS	181	struct amdtp_dot *p = s->protocol;
bb473966	182	unsigned int channels = p->pcm_channels;
163ae6f3	183	struct snd_pcm_runtime *runtime = pcm->runtime;
bb473966 TS	184	unsigned int pcm_buffer_pointer;
bb473966 TS	185	int remaining_frames;
163ae6f3	186	u32 *dst;
bb473966 TS	187	int i, c;
	188
	189	pcm_buffer_pointer = s->pcm_buffer_pointer + pcm_frames;
	190	pcm_buffer_pointer %= runtime->buffer_size;
163ae6f3	191
163ae6f3	192	dst = (void *)runtime->dma_area +
bb473966 TS	193	frames_to_bytes(runtime, pcm_buffer_pointer);
bb473966 TS	194	remaining_frames = runtime->buffer_size - pcm_buffer_pointer;
163ae6f3 TS	195
	196	buffer++;
	197	for (i = 0; i < frames; ++i) {
	198	for (c = 0; c < channels; ++c) {
	199	*dst = be32_to_cpu(buffer[c]) << 8;
	200	dst++;
	201	}
	202	buffer += s->data_block_quadlets;
	203	if (--remaining_frames == 0)
	204	dst = (void *)runtime->dma_area;
	205	}
	206	}
	207
	208	static void write_pcm_silence(struct amdtp_stream s, __be32 buffer,
	209	unsigned int data_blocks)
	210	{
	211	struct amdtp_dot *p = s->protocol;
	212	unsigned int channels, i, c;
	213
	214	channels = p->pcm_channels;
	215
	216	buffer++;
	217	for (i = 0; i < data_blocks; ++i) {
	218	for (c = 0; c < channels; ++c)
	219	buffer[c] = cpu_to_be32(0x40000000);
	220	buffer += s->data_block_quadlets;
	221	}
	222	}
	223
9dc5d31c TS	224	static bool midi_ratelimit_per_packet(struct amdtp_stream *s, unsigned int port)
	225	{
	226	struct amdtp_dot *p = s->protocol;
	227	int used;
	228
	229	used = p->midi_fifo_used[port];
	230	if (used == 0)
	231	return true;
	232
	233	used -= MIDI_BYTES_PER_SECOND * s->syt_interval;
	234	used = max(used, 0);
	235	p->midi_fifo_used[port] = used;
	236
	237	return used < p->midi_fifo_limit;
	238	}
	239
	240	static inline void midi_use_bytes(struct amdtp_stream *s,
	241	unsigned int port, unsigned int count)
	242	{
	243	struct amdtp_dot *p = s->protocol;
	244
	245	p->midi_fifo_used[port] += amdtp_rate_table[s->sfc] * count;
	246	}
	247
	248	static void write_midi_messages(struct amdtp_stream s, __be32 buffer,
ab754812	249	unsigned int data_blocks, unsigned int data_block_counter)
9dc5d31c TS	250	{
	251	struct amdtp_dot *p = s->protocol;
	252	unsigned int f, port;
	253	int len;
	254	u8 *b;
	255
	256	for (f = 0; f < data_blocks; f++) {
ab754812	257	port = (data_block_counter + f) % 8;
9dc5d31c TS	258	b = (u8 *)&buffer[0];
	259
	260	len = 0;
8820a4cf	261	if (port < MAX_MIDI_PORTS &&
9dc5d31c TS	262	midi_ratelimit_per_packet(s, port) &&
	263	p->midi[port] != NULL)
	264	len = snd_rawmidi_transmit(p->midi[port], b + 1, 2);
	265
	266	if (len > 0) {
8820a4cf TS	267	/*
	268	* Upper 4 bits of LSB represent port number.
	269	* - 0000b: physical MIDI port 1.
	270	* - 0010b: physical MIDI port 2.
	271	* - 1110b: console MIDI port.
	272	*/
	273	if (port == 2)
	274	b[3] = 0xe0;
	275	else if (port == 1)
	276	b[3] = 0x20;
	277	else
	278	b[3] = 0x00;
	279	b[3] \|= len;
9dc5d31c TS	280	midi_use_bytes(s, port, len);
	281	} else {
	282	b[1] = 0;
	283	b[2] = 0;
	284	b[3] = 0;
	285	}
	286	b[0] = 0x80;
	287
	288	buffer += s->data_block_quadlets;
	289	}
	290	}
	291
	292	static void read_midi_messages(struct amdtp_stream s, __be32 buffer,
	293	unsigned int data_blocks)
	294	{
	295	struct amdtp_dot *p = s->protocol;
	296	unsigned int f, port, len;
	297	u8 *b;
	298
	299	for (f = 0; f < data_blocks; f++) {
	300	b = (u8 *)&buffer[0];
9dc5d31c	301
8820a4cf TS	302	len = b[3] & 0x0f;
	303	if (len > 0) {
	304	/*
	305	* Upper 4 bits of LSB represent port number.
	306	* - 0000b: physical MIDI port 1. Use port 0.
	307	* - 1110b: console MIDI port. Use port 2.
	308	*/
	309	if (b[3] >> 4 > 0)
	310	port = 2;
	311	else
	312	port = 0;
	313
	314	if (port < MAX_MIDI_PORTS && p->midi[port])
	315	snd_rawmidi_receive(p->midi[port], b + 1, len);
	316	}
9dc5d31c TS	317
	318	buffer += s->data_block_quadlets;
	319	}
	320	}
	321
163ae6f3 TS	322	int amdtp_dot_add_pcm_hw_constraints(struct amdtp_stream *s,
	323	struct snd_pcm_runtime *runtime)
	324	{
	325	int err;
	326
	327	/* This protocol delivers 24 bit data in 32bit data channel. */
	328	err = snd_pcm_hw_constraint_msbits(runtime, 0, 32, 24);
	329	if (err < 0)
	330	return err;
	331
	332	return amdtp_stream_add_pcm_hw_constraints(s, runtime);
	333	}
	334
9dc5d31c TS	335	void amdtp_dot_midi_trigger(struct amdtp_stream *s, unsigned int port,
	336	struct snd_rawmidi_substream *midi)
	337	{
	338	struct amdtp_dot *p = s->protocol;
	339
8820a4cf	340	if (port < MAX_MIDI_PORTS)
6aa7de05	341	WRITE_ONCE(p->midi[port], midi);
9dc5d31c TS	342	}
9dc5d31c TS	343
163ae6f3	344	static unsigned int process_tx_data_blocks(struct amdtp_stream *s,
d2c104a3 TS	345	const struct pkt_desc *desc,
d2c104a3 TS	346	struct snd_pcm_substream *pcm)
163ae6f3	347	{
bb473966	348	unsigned int pcm_frames = 0;
163ae6f3	349
163ae6f3	350	if (pcm) {
bb473966 TS	351	read_pcm_s32(s, pcm, desc->ctx_payload, desc->data_blocks,
bb473966 TS	352	pcm_frames);
d2c104a3	353	pcm_frames = desc->data_blocks;
163ae6f3 TS	354	}
163ae6f3 TS	355
d2c104a3	356	read_midi_messages(s, desc->ctx_payload, desc->data_blocks);
163ae6f3 TS	357
	358	return pcm_frames;
	359	}
	360
	361	static unsigned int process_rx_data_blocks(struct amdtp_stream *s,
d2c104a3 TS	362	const struct pkt_desc *desc,
d2c104a3 TS	363	struct snd_pcm_substream *pcm)
163ae6f3	364	{
bb473966	365	unsigned int pcm_frames = 0;
163ae6f3	366
163ae6f3	367	if (pcm) {
bb473966 TS	368	write_pcm_s32(s, pcm, desc->ctx_payload, desc->data_blocks,
bb473966 TS	369	pcm_frames);
d2c104a3	370	pcm_frames = desc->data_blocks;
163ae6f3	371	} else {
d2c104a3	372	write_pcm_silence(s, desc->ctx_payload, desc->data_blocks);
163ae6f3 TS	373	}
163ae6f3 TS	374
d2c104a3 TS	375	write_midi_messages(s, desc->ctx_payload, desc->data_blocks,
d2c104a3 TS	376	desc->data_block_counter);
163ae6f3 TS	377
	378	return pcm_frames;
	379	}
	380
	381	int amdtp_dot_init(struct amdtp_stream s, struct fw_unit unit,
	382	enum amdtp_stream_direction dir)
	383	{
	384	amdtp_stream_process_data_blocks_t process_data_blocks;
	385	enum cip_flags flags;
	386
	387	/* Use different mode between incoming/outgoing. */
	388	if (dir == AMDTP_IN_STREAM) {
62f00e40	389	flags = CIP_NONBLOCKING;
163ae6f3 TS	390	process_data_blocks = process_tx_data_blocks;
	391	} else {
	392	flags = CIP_BLOCKING;
	393	process_data_blocks = process_rx_data_blocks;
	394	}
	395
	396	return amdtp_stream_init(s, unit, dir, flags, CIP_FMT_AM,
	397	process_data_blocks, sizeof(struct amdtp_dot));
	398	}
	399
	400	void amdtp_dot_reset(struct amdtp_stream *s)
	401	{
	402	struct amdtp_dot *p = s->protocol;
	403
	404	p->state.carry = 0x00;
	405	p->state.idx = 0x00;
	406	p->state.off = 0;
	407	}