Takashi Sakamoto | 163ae6f | 2015-09-30 09:39:17 +0900 | [diff] [blame] | 1 | /* |
| 2 | * amdtp-dot.c - a part of driver for Digidesign Digi 002/003 family |
| 3 | * |
| 4 | * Copyright (c) 2014-2015 Takashi Sakamoto |
| 5 | * Copyright (C) 2012 Robin Gareus <robin@gareus.org> |
| 6 | * Copyright (C) 2012 Damien Zammit <damien@zamaudio.com> |
| 7 | * |
| 8 | * Licensed under the terms of the GNU General Public License, version 2. |
| 9 | */ |
| 10 | |
| 11 | #include <sound/pcm.h> |
| 12 | #include "digi00x.h" |
| 13 | |
| 14 | #define CIP_FMT_AM 0x10 |
| 15 | |
| 16 | /* 'Clock-based rate control mode' is just supported. */ |
| 17 | #define AMDTP_FDF_AM824 0x00 |
| 18 | |
| 19 | /* |
Takashi Sakamoto | 9dc5d31 | 2015-10-11 12:30:15 +0900 | [diff] [blame^] | 20 | * Nominally 3125 bytes/second, but the MIDI port's clock might be |
| 21 | * 1% too slow, and the bus clock 100 ppm too fast. |
| 22 | */ |
| 23 | #define MIDI_BYTES_PER_SECOND 3093 |
| 24 | |
| 25 | /* |
| 26 | * Several devices look only at the first eight data blocks. |
| 27 | * In any case, this is more than enough for the MIDI data rate. |
| 28 | */ |
| 29 | #define MAX_MIDI_RX_BLOCKS 8 |
| 30 | |
| 31 | /* |
Takashi Sakamoto | 163ae6f | 2015-09-30 09:39:17 +0900 | [diff] [blame] | 32 | * The double-oh-three algorithm was discovered by Robin Gareus and Damien |
| 33 | * Zammit in 2012, with reverse-engineering for Digi 003 Rack. |
| 34 | */ |
| 35 | struct dot_state { |
Takashi Sakamoto | 17385a3 | 2015-10-11 12:30:14 +0900 | [diff] [blame] | 36 | u8 carry; |
| 37 | u8 idx; |
Takashi Sakamoto | 163ae6f | 2015-09-30 09:39:17 +0900 | [diff] [blame] | 38 | unsigned int off; |
| 39 | }; |
| 40 | |
| 41 | struct amdtp_dot { |
| 42 | unsigned int pcm_channels; |
| 43 | struct dot_state state; |
| 44 | |
| 45 | unsigned int midi_ports; |
Takashi Sakamoto | 9dc5d31 | 2015-10-11 12:30:15 +0900 | [diff] [blame^] | 46 | /* 2 = MAX(DOT_MIDI_IN_PORTS, DOT_MIDI_OUT_PORTS) */ |
| 47 | struct snd_rawmidi_substream *midi[2]; |
| 48 | int midi_fifo_used[2]; |
| 49 | int midi_fifo_limit; |
Takashi Sakamoto | 163ae6f | 2015-09-30 09:39:17 +0900 | [diff] [blame] | 50 | |
| 51 | void (*transfer_samples)(struct amdtp_stream *s, |
| 52 | struct snd_pcm_substream *pcm, |
| 53 | __be32 *buffer, unsigned int frames); |
| 54 | }; |
| 55 | |
| 56 | /* |
| 57 | * double-oh-three look up table |
| 58 | * |
| 59 | * @param idx index byte (audio-sample data) 0x00..0xff |
| 60 | * @param off channel offset shift |
| 61 | * @return salt to XOR with given data |
| 62 | */ |
| 63 | #define BYTE_PER_SAMPLE (4) |
| 64 | #define MAGIC_DOT_BYTE (2) |
| 65 | #define MAGIC_BYTE_OFF(x) (((x) * BYTE_PER_SAMPLE) + MAGIC_DOT_BYTE) |
Takashi Sakamoto | 17385a3 | 2015-10-11 12:30:14 +0900 | [diff] [blame] | 66 | static const u8 dot_scrt(const u8 idx, const unsigned int off) |
Takashi Sakamoto | 163ae6f | 2015-09-30 09:39:17 +0900 | [diff] [blame] | 67 | { |
| 68 | /* |
| 69 | * the length of the added pattern only depends on the lower nibble |
| 70 | * of the last non-zero data |
| 71 | */ |
Takashi Sakamoto | 17385a3 | 2015-10-11 12:30:14 +0900 | [diff] [blame] | 72 | static const u8 len[16] = {0, 1, 3, 5, 7, 9, 11, 13, 14, |
| 73 | 12, 10, 8, 6, 4, 2, 0}; |
Takashi Sakamoto | 163ae6f | 2015-09-30 09:39:17 +0900 | [diff] [blame] | 74 | |
| 75 | /* |
| 76 | * the lower nibble of the salt. Interleaved sequence. |
| 77 | * this is walked backwards according to len[] |
| 78 | */ |
Takashi Sakamoto | 17385a3 | 2015-10-11 12:30:14 +0900 | [diff] [blame] | 79 | static const u8 nib[15] = {0x8, 0x7, 0x9, 0x6, 0xa, 0x5, 0xb, 0x4, |
| 80 | 0xc, 0x3, 0xd, 0x2, 0xe, 0x1, 0xf}; |
Takashi Sakamoto | 163ae6f | 2015-09-30 09:39:17 +0900 | [diff] [blame] | 81 | |
| 82 | /* circular list for the salt's hi nibble. */ |
Takashi Sakamoto | 17385a3 | 2015-10-11 12:30:14 +0900 | [diff] [blame] | 83 | static const u8 hir[15] = {0x0, 0x6, 0xf, 0x8, 0x7, 0x5, 0x3, 0x4, |
| 84 | 0xc, 0xd, 0xe, 0x1, 0x2, 0xb, 0xa}; |
Takashi Sakamoto | 163ae6f | 2015-09-30 09:39:17 +0900 | [diff] [blame] | 85 | |
| 86 | /* |
| 87 | * start offset for upper nibble mapping. |
| 88 | * note: 9 is /special/. In the case where the high nibble == 0x9, |
| 89 | * hir[] is not used and - coincidentally - the salt's hi nibble is |
| 90 | * 0x09 regardless of the offset. |
| 91 | */ |
Takashi Sakamoto | 17385a3 | 2015-10-11 12:30:14 +0900 | [diff] [blame] | 92 | static const u8 hio[16] = {0, 11, 12, 6, 7, 5, 1, 4, |
| 93 | 3, 0x00, 14, 13, 8, 9, 10, 2}; |
Takashi Sakamoto | 163ae6f | 2015-09-30 09:39:17 +0900 | [diff] [blame] | 94 | |
Takashi Sakamoto | 17385a3 | 2015-10-11 12:30:14 +0900 | [diff] [blame] | 95 | const u8 ln = idx & 0xf; |
| 96 | const u8 hn = (idx >> 4) & 0xf; |
| 97 | const u8 hr = (hn == 0x9) ? 0x9 : hir[(hio[hn] + off) % 15]; |
Takashi Sakamoto | 163ae6f | 2015-09-30 09:39:17 +0900 | [diff] [blame] | 98 | |
| 99 | if (len[ln] < off) |
| 100 | return 0x00; |
| 101 | |
| 102 | return ((nib[14 + off - len[ln]]) | (hr << 4)); |
| 103 | } |
| 104 | |
| 105 | static void dot_encode_step(struct dot_state *state, __be32 *const buffer) |
| 106 | { |
Takashi Sakamoto | 17385a3 | 2015-10-11 12:30:14 +0900 | [diff] [blame] | 107 | u8 * const data = (u8 *) buffer; |
Takashi Sakamoto | 163ae6f | 2015-09-30 09:39:17 +0900 | [diff] [blame] | 108 | |
| 109 | if (data[MAGIC_DOT_BYTE] != 0x00) { |
| 110 | state->off = 0; |
| 111 | state->idx = data[MAGIC_DOT_BYTE] ^ state->carry; |
| 112 | } |
| 113 | data[MAGIC_DOT_BYTE] ^= state->carry; |
| 114 | state->carry = dot_scrt(state->idx, ++(state->off)); |
| 115 | } |
| 116 | |
| 117 | int amdtp_dot_set_parameters(struct amdtp_stream *s, unsigned int rate, |
Takashi Sakamoto | 9dc5d31 | 2015-10-11 12:30:15 +0900 | [diff] [blame^] | 118 | unsigned int pcm_channels) |
Takashi Sakamoto | 163ae6f | 2015-09-30 09:39:17 +0900 | [diff] [blame] | 119 | { |
| 120 | struct amdtp_dot *p = s->protocol; |
| 121 | int err; |
| 122 | |
| 123 | if (amdtp_stream_running(s)) |
| 124 | return -EBUSY; |
| 125 | |
| 126 | /* |
| 127 | * A first data channel is for MIDI conformant data channel, the rest is |
| 128 | * Multi Bit Linear Audio data channel. |
| 129 | */ |
| 130 | err = amdtp_stream_set_parameters(s, rate, pcm_channels + 1); |
| 131 | if (err < 0) |
| 132 | return err; |
| 133 | |
| 134 | s->fdf = AMDTP_FDF_AM824 | s->sfc; |
| 135 | |
| 136 | p->pcm_channels = pcm_channels; |
Takashi Sakamoto | 9dc5d31 | 2015-10-11 12:30:15 +0900 | [diff] [blame^] | 137 | |
| 138 | if (s->direction == AMDTP_IN_STREAM) |
| 139 | p->midi_ports = DOT_MIDI_IN_PORTS; |
| 140 | else |
| 141 | p->midi_ports = DOT_MIDI_OUT_PORTS; |
| 142 | |
| 143 | /* |
| 144 | * We do not know the actual MIDI FIFO size of most devices. Just |
| 145 | * assume two bytes, i.e., one byte can be received over the bus while |
| 146 | * the previous one is transmitted over MIDI. |
| 147 | * (The value here is adjusted for midi_ratelimit_per_packet().) |
| 148 | */ |
| 149 | p->midi_fifo_limit = rate - MIDI_BYTES_PER_SECOND * s->syt_interval + 1; |
Takashi Sakamoto | 163ae6f | 2015-09-30 09:39:17 +0900 | [diff] [blame] | 150 | |
| 151 | return 0; |
| 152 | } |
| 153 | |
| 154 | static void write_pcm_s32(struct amdtp_stream *s, struct snd_pcm_substream *pcm, |
| 155 | __be32 *buffer, unsigned int frames) |
| 156 | { |
| 157 | struct amdtp_dot *p = s->protocol; |
| 158 | struct snd_pcm_runtime *runtime = pcm->runtime; |
| 159 | unsigned int channels, remaining_frames, i, c; |
| 160 | const u32 *src; |
| 161 | |
| 162 | channels = p->pcm_channels; |
| 163 | src = (void *)runtime->dma_area + |
| 164 | frames_to_bytes(runtime, s->pcm_buffer_pointer); |
| 165 | remaining_frames = runtime->buffer_size - s->pcm_buffer_pointer; |
| 166 | |
| 167 | buffer++; |
| 168 | for (i = 0; i < frames; ++i) { |
| 169 | for (c = 0; c < channels; ++c) { |
| 170 | buffer[c] = cpu_to_be32((*src >> 8) | 0x40000000); |
| 171 | dot_encode_step(&p->state, &buffer[c]); |
| 172 | src++; |
| 173 | } |
| 174 | buffer += s->data_block_quadlets; |
| 175 | if (--remaining_frames == 0) |
| 176 | src = (void *)runtime->dma_area; |
| 177 | } |
| 178 | } |
| 179 | |
| 180 | static void write_pcm_s16(struct amdtp_stream *s, struct snd_pcm_substream *pcm, |
| 181 | __be32 *buffer, unsigned int frames) |
| 182 | { |
| 183 | struct amdtp_dot *p = s->protocol; |
| 184 | struct snd_pcm_runtime *runtime = pcm->runtime; |
| 185 | unsigned int channels, remaining_frames, i, c; |
| 186 | const u16 *src; |
| 187 | |
| 188 | channels = p->pcm_channels; |
| 189 | src = (void *)runtime->dma_area + |
| 190 | frames_to_bytes(runtime, s->pcm_buffer_pointer); |
| 191 | remaining_frames = runtime->buffer_size - s->pcm_buffer_pointer; |
| 192 | |
| 193 | buffer++; |
| 194 | for (i = 0; i < frames; ++i) { |
| 195 | for (c = 0; c < channels; ++c) { |
| 196 | buffer[c] = cpu_to_be32((*src << 8) | 0x40000000); |
| 197 | dot_encode_step(&p->state, &buffer[c]); |
| 198 | src++; |
| 199 | } |
| 200 | buffer += s->data_block_quadlets; |
| 201 | if (--remaining_frames == 0) |
| 202 | src = (void *)runtime->dma_area; |
| 203 | } |
| 204 | } |
| 205 | |
| 206 | static void read_pcm_s32(struct amdtp_stream *s, struct snd_pcm_substream *pcm, |
| 207 | __be32 *buffer, unsigned int frames) |
| 208 | { |
| 209 | struct amdtp_dot *p = s->protocol; |
| 210 | struct snd_pcm_runtime *runtime = pcm->runtime; |
| 211 | unsigned int channels, remaining_frames, i, c; |
| 212 | u32 *dst; |
| 213 | |
| 214 | channels = p->pcm_channels; |
| 215 | dst = (void *)runtime->dma_area + |
| 216 | frames_to_bytes(runtime, s->pcm_buffer_pointer); |
| 217 | remaining_frames = runtime->buffer_size - s->pcm_buffer_pointer; |
| 218 | |
| 219 | buffer++; |
| 220 | for (i = 0; i < frames; ++i) { |
| 221 | for (c = 0; c < channels; ++c) { |
| 222 | *dst = be32_to_cpu(buffer[c]) << 8; |
| 223 | dst++; |
| 224 | } |
| 225 | buffer += s->data_block_quadlets; |
| 226 | if (--remaining_frames == 0) |
| 227 | dst = (void *)runtime->dma_area; |
| 228 | } |
| 229 | } |
| 230 | |
| 231 | static void write_pcm_silence(struct amdtp_stream *s, __be32 *buffer, |
| 232 | unsigned int data_blocks) |
| 233 | { |
| 234 | struct amdtp_dot *p = s->protocol; |
| 235 | unsigned int channels, i, c; |
| 236 | |
| 237 | channels = p->pcm_channels; |
| 238 | |
| 239 | buffer++; |
| 240 | for (i = 0; i < data_blocks; ++i) { |
| 241 | for (c = 0; c < channels; ++c) |
| 242 | buffer[c] = cpu_to_be32(0x40000000); |
| 243 | buffer += s->data_block_quadlets; |
| 244 | } |
| 245 | } |
| 246 | |
Takashi Sakamoto | 9dc5d31 | 2015-10-11 12:30:15 +0900 | [diff] [blame^] | 247 | static bool midi_ratelimit_per_packet(struct amdtp_stream *s, unsigned int port) |
| 248 | { |
| 249 | struct amdtp_dot *p = s->protocol; |
| 250 | int used; |
| 251 | |
| 252 | used = p->midi_fifo_used[port]; |
| 253 | if (used == 0) |
| 254 | return true; |
| 255 | |
| 256 | used -= MIDI_BYTES_PER_SECOND * s->syt_interval; |
| 257 | used = max(used, 0); |
| 258 | p->midi_fifo_used[port] = used; |
| 259 | |
| 260 | return used < p->midi_fifo_limit; |
| 261 | } |
| 262 | |
| 263 | static inline void midi_use_bytes(struct amdtp_stream *s, |
| 264 | unsigned int port, unsigned int count) |
| 265 | { |
| 266 | struct amdtp_dot *p = s->protocol; |
| 267 | |
| 268 | p->midi_fifo_used[port] += amdtp_rate_table[s->sfc] * count; |
| 269 | } |
| 270 | |
| 271 | static void write_midi_messages(struct amdtp_stream *s, __be32 *buffer, |
| 272 | unsigned int data_blocks) |
| 273 | { |
| 274 | struct amdtp_dot *p = s->protocol; |
| 275 | unsigned int f, port; |
| 276 | int len; |
| 277 | u8 *b; |
| 278 | |
| 279 | for (f = 0; f < data_blocks; f++) { |
| 280 | port = (s->data_block_counter + f) % 8; |
| 281 | b = (u8 *)&buffer[0]; |
| 282 | |
| 283 | len = 0; |
| 284 | if (port < p->midi_ports && |
| 285 | midi_ratelimit_per_packet(s, port) && |
| 286 | p->midi[port] != NULL) |
| 287 | len = snd_rawmidi_transmit(p->midi[port], b + 1, 2); |
| 288 | |
| 289 | if (len > 0) { |
| 290 | b[3] = (0x10 << port) | len; |
| 291 | midi_use_bytes(s, port, len); |
| 292 | } else { |
| 293 | b[1] = 0; |
| 294 | b[2] = 0; |
| 295 | b[3] = 0; |
| 296 | } |
| 297 | b[0] = 0x80; |
| 298 | |
| 299 | buffer += s->data_block_quadlets; |
| 300 | } |
| 301 | } |
| 302 | |
| 303 | static void read_midi_messages(struct amdtp_stream *s, __be32 *buffer, |
| 304 | unsigned int data_blocks) |
| 305 | { |
| 306 | struct amdtp_dot *p = s->protocol; |
| 307 | unsigned int f, port, len; |
| 308 | u8 *b; |
| 309 | |
| 310 | for (f = 0; f < data_blocks; f++) { |
| 311 | b = (u8 *)&buffer[0]; |
| 312 | port = b[3] >> 4; |
| 313 | len = b[3] & 0x0f; |
| 314 | |
| 315 | if (port < p->midi_ports && p->midi[port] && len > 0) |
| 316 | snd_rawmidi_receive(p->midi[port], b + 1, len); |
| 317 | |
| 318 | buffer += s->data_block_quadlets; |
| 319 | } |
| 320 | } |
| 321 | |
Takashi Sakamoto | 163ae6f | 2015-09-30 09:39:17 +0900 | [diff] [blame] | 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 | |
| 335 | void amdtp_dot_set_pcm_format(struct amdtp_stream *s, snd_pcm_format_t format) |
| 336 | { |
| 337 | struct amdtp_dot *p = s->protocol; |
| 338 | |
| 339 | if (WARN_ON(amdtp_stream_pcm_running(s))) |
| 340 | return; |
| 341 | |
| 342 | switch (format) { |
| 343 | default: |
| 344 | WARN_ON(1); |
| 345 | /* fall through */ |
| 346 | case SNDRV_PCM_FORMAT_S16: |
| 347 | if (s->direction == AMDTP_OUT_STREAM) { |
| 348 | p->transfer_samples = write_pcm_s16; |
| 349 | break; |
| 350 | } |
| 351 | WARN_ON(1); |
| 352 | /* fall through */ |
| 353 | case SNDRV_PCM_FORMAT_S32: |
| 354 | if (s->direction == AMDTP_OUT_STREAM) |
| 355 | p->transfer_samples = write_pcm_s32; |
| 356 | else |
| 357 | p->transfer_samples = read_pcm_s32; |
| 358 | break; |
| 359 | } |
| 360 | } |
| 361 | |
Takashi Sakamoto | 9dc5d31 | 2015-10-11 12:30:15 +0900 | [diff] [blame^] | 362 | void amdtp_dot_midi_trigger(struct amdtp_stream *s, unsigned int port, |
| 363 | struct snd_rawmidi_substream *midi) |
| 364 | { |
| 365 | struct amdtp_dot *p = s->protocol; |
| 366 | |
| 367 | if (port < p->midi_ports) |
| 368 | ACCESS_ONCE(p->midi[port]) = midi; |
| 369 | } |
| 370 | |
Takashi Sakamoto | 163ae6f | 2015-09-30 09:39:17 +0900 | [diff] [blame] | 371 | static unsigned int process_tx_data_blocks(struct amdtp_stream *s, |
| 372 | __be32 *buffer, |
| 373 | unsigned int data_blocks, |
| 374 | unsigned int *syt) |
| 375 | { |
| 376 | struct amdtp_dot *p = (struct amdtp_dot *)s->protocol; |
| 377 | struct snd_pcm_substream *pcm; |
| 378 | unsigned int pcm_frames; |
| 379 | |
| 380 | pcm = ACCESS_ONCE(s->pcm); |
| 381 | if (pcm) { |
| 382 | p->transfer_samples(s, pcm, buffer, data_blocks); |
| 383 | pcm_frames = data_blocks; |
| 384 | } else { |
| 385 | pcm_frames = 0; |
| 386 | } |
| 387 | |
Takashi Sakamoto | 9dc5d31 | 2015-10-11 12:30:15 +0900 | [diff] [blame^] | 388 | read_midi_messages(s, buffer, data_blocks); |
Takashi Sakamoto | 163ae6f | 2015-09-30 09:39:17 +0900 | [diff] [blame] | 389 | |
| 390 | return pcm_frames; |
| 391 | } |
| 392 | |
| 393 | static unsigned int process_rx_data_blocks(struct amdtp_stream *s, |
| 394 | __be32 *buffer, |
| 395 | unsigned int data_blocks, |
| 396 | unsigned int *syt) |
| 397 | { |
| 398 | struct amdtp_dot *p = (struct amdtp_dot *)s->protocol; |
| 399 | struct snd_pcm_substream *pcm; |
| 400 | unsigned int pcm_frames; |
| 401 | |
| 402 | pcm = ACCESS_ONCE(s->pcm); |
| 403 | if (pcm) { |
| 404 | p->transfer_samples(s, pcm, buffer, data_blocks); |
| 405 | pcm_frames = data_blocks; |
| 406 | } else { |
| 407 | write_pcm_silence(s, buffer, data_blocks); |
| 408 | pcm_frames = 0; |
| 409 | } |
| 410 | |
Takashi Sakamoto | 9dc5d31 | 2015-10-11 12:30:15 +0900 | [diff] [blame^] | 411 | write_midi_messages(s, buffer, data_blocks); |
Takashi Sakamoto | 163ae6f | 2015-09-30 09:39:17 +0900 | [diff] [blame] | 412 | |
| 413 | return pcm_frames; |
| 414 | } |
| 415 | |
| 416 | int amdtp_dot_init(struct amdtp_stream *s, struct fw_unit *unit, |
| 417 | enum amdtp_stream_direction dir) |
| 418 | { |
| 419 | amdtp_stream_process_data_blocks_t process_data_blocks; |
| 420 | enum cip_flags flags; |
| 421 | |
| 422 | /* Use different mode between incoming/outgoing. */ |
| 423 | if (dir == AMDTP_IN_STREAM) { |
| 424 | flags = CIP_NONBLOCKING | CIP_SKIP_INIT_DBC_CHECK; |
| 425 | process_data_blocks = process_tx_data_blocks; |
| 426 | } else { |
| 427 | flags = CIP_BLOCKING; |
| 428 | process_data_blocks = process_rx_data_blocks; |
| 429 | } |
| 430 | |
| 431 | return amdtp_stream_init(s, unit, dir, flags, CIP_FMT_AM, |
| 432 | process_data_blocks, sizeof(struct amdtp_dot)); |
| 433 | } |
| 434 | |
| 435 | void amdtp_dot_reset(struct amdtp_stream *s) |
| 436 | { |
| 437 | struct amdtp_dot *p = s->protocol; |
| 438 | |
| 439 | p->state.carry = 0x00; |
| 440 | p->state.idx = 0x00; |
| 441 | p->state.off = 0; |
| 442 | } |