Commit | Line | Data |
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163ae6f3 TS |
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 | ||
9dc5d31c TS |
19 | /* |
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 | ||
163ae6f3 TS |
31 | /* |
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 { | |
17385a38 TS |
36 | u8 carry; |
37 | u8 idx; | |
163ae6f3 TS |
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; | |
9dc5d31c TS |
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; | |
163ae6f3 TS |
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) | |
b8cb3750 | 66 | static u8 dot_scrt(const u8 idx, const unsigned int off) |
163ae6f3 TS |
67 | { |
68 | /* | |
69 | * the length of the added pattern only depends on the lower nibble | |
70 | * of the last non-zero data | |
71 | */ | |
17385a38 TS |
72 | static const u8 len[16] = {0, 1, 3, 5, 7, 9, 11, 13, 14, |
73 | 12, 10, 8, 6, 4, 2, 0}; | |
163ae6f3 TS |
74 | |
75 | /* | |
76 | * the lower nibble of the salt. Interleaved sequence. | |
77 | * this is walked backwards according to len[] | |
78 | */ | |
17385a38 TS |
79 | static const u8 nib[15] = {0x8, 0x7, 0x9, 0x6, 0xa, 0x5, 0xb, 0x4, |
80 | 0xc, 0x3, 0xd, 0x2, 0xe, 0x1, 0xf}; | |
163ae6f3 TS |
81 | |
82 | /* circular list for the salt's hi nibble. */ | |
17385a38 TS |
83 | static const u8 hir[15] = {0x0, 0x6, 0xf, 0x8, 0x7, 0x5, 0x3, 0x4, |
84 | 0xc, 0xd, 0xe, 0x1, 0x2, 0xb, 0xa}; | |
163ae6f3 TS |
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 | */ | |
17385a38 TS |
92 | static const u8 hio[16] = {0, 11, 12, 6, 7, 5, 1, 4, |
93 | 3, 0x00, 14, 13, 8, 9, 10, 2}; | |
163ae6f3 | 94 | |
17385a38 TS |
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]; | |
163ae6f3 TS |
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 | { | |
17385a38 | 107 | u8 * const data = (u8 *) buffer; |
163ae6f3 TS |
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, | |
9dc5d31c | 118 | unsigned int pcm_channels) |
163ae6f3 TS |
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; | |
9dc5d31c TS |
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; | |
163ae6f3 TS |
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 | ||
9dc5d31c TS |
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 | ||
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 | ||
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 | ||
9dc5d31c TS |
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 | ||
163ae6f3 TS |
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 | ||
9dc5d31c | 388 | read_midi_messages(s, buffer, data_blocks); |
163ae6f3 TS |
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 | ||
9dc5d31c | 411 | write_midi_messages(s, buffer, data_blocks); |
163ae6f3 TS |
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 | } |