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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 | ||
8820a4cf TS |
31 | /* 3 = MAX(DOT_MIDI_IN_PORTS, DOT_MIDI_OUT_PORTS) + 1. */ |
32 | #define MAX_MIDI_PORTS 3 | |
33 | ||
163ae6f3 TS |
34 | /* |
35 | * The double-oh-three algorithm was discovered by Robin Gareus and Damien | |
36 | * Zammit in 2012, with reverse-engineering for Digi 003 Rack. | |
37 | */ | |
38 | struct dot_state { | |
17385a38 TS |
39 | u8 carry; |
40 | u8 idx; | |
163ae6f3 TS |
41 | unsigned int off; |
42 | }; | |
43 | ||
44 | struct amdtp_dot { | |
45 | unsigned int pcm_channels; | |
46 | struct dot_state state; | |
47 | ||
8820a4cf TS |
48 | struct snd_rawmidi_substream *midi[MAX_MIDI_PORTS]; |
49 | int midi_fifo_used[MAX_MIDI_PORTS]; | |
9dc5d31c | 50 | int midi_fifo_limit; |
163ae6f3 TS |
51 | }; |
52 | ||
53 | /* | |
54 | * double-oh-three look up table | |
55 | * | |
56 | * @param idx index byte (audio-sample data) 0x00..0xff | |
57 | * @param off channel offset shift | |
58 | * @return salt to XOR with given data | |
59 | */ | |
60 | #define BYTE_PER_SAMPLE (4) | |
61 | #define MAGIC_DOT_BYTE (2) | |
62 | #define MAGIC_BYTE_OFF(x) (((x) * BYTE_PER_SAMPLE) + MAGIC_DOT_BYTE) | |
b8cb3750 | 63 | static u8 dot_scrt(const u8 idx, const unsigned int off) |
163ae6f3 TS |
64 | { |
65 | /* | |
66 | * the length of the added pattern only depends on the lower nibble | |
67 | * of the last non-zero data | |
68 | */ | |
17385a38 TS |
69 | static const u8 len[16] = {0, 1, 3, 5, 7, 9, 11, 13, 14, |
70 | 12, 10, 8, 6, 4, 2, 0}; | |
163ae6f3 TS |
71 | |
72 | /* | |
73 | * the lower nibble of the salt. Interleaved sequence. | |
74 | * this is walked backwards according to len[] | |
75 | */ | |
17385a38 TS |
76 | static const u8 nib[15] = {0x8, 0x7, 0x9, 0x6, 0xa, 0x5, 0xb, 0x4, |
77 | 0xc, 0x3, 0xd, 0x2, 0xe, 0x1, 0xf}; | |
163ae6f3 TS |
78 | |
79 | /* circular list for the salt's hi nibble. */ | |
17385a38 TS |
80 | static const u8 hir[15] = {0x0, 0x6, 0xf, 0x8, 0x7, 0x5, 0x3, 0x4, |
81 | 0xc, 0xd, 0xe, 0x1, 0x2, 0xb, 0xa}; | |
163ae6f3 TS |
82 | |
83 | /* | |
84 | * start offset for upper nibble mapping. | |
85 | * note: 9 is /special/. In the case where the high nibble == 0x9, | |
86 | * hir[] is not used and - coincidentally - the salt's hi nibble is | |
87 | * 0x09 regardless of the offset. | |
88 | */ | |
17385a38 TS |
89 | static const u8 hio[16] = {0, 11, 12, 6, 7, 5, 1, 4, |
90 | 3, 0x00, 14, 13, 8, 9, 10, 2}; | |
163ae6f3 | 91 | |
17385a38 TS |
92 | const u8 ln = idx & 0xf; |
93 | const u8 hn = (idx >> 4) & 0xf; | |
94 | const u8 hr = (hn == 0x9) ? 0x9 : hir[(hio[hn] + off) % 15]; | |
163ae6f3 TS |
95 | |
96 | if (len[ln] < off) | |
97 | return 0x00; | |
98 | ||
99 | return ((nib[14 + off - len[ln]]) | (hr << 4)); | |
100 | } | |
101 | ||
102 | static void dot_encode_step(struct dot_state *state, __be32 *const buffer) | |
103 | { | |
17385a38 | 104 | u8 * const data = (u8 *) buffer; |
163ae6f3 TS |
105 | |
106 | if (data[MAGIC_DOT_BYTE] != 0x00) { | |
107 | state->off = 0; | |
108 | state->idx = data[MAGIC_DOT_BYTE] ^ state->carry; | |
109 | } | |
110 | data[MAGIC_DOT_BYTE] ^= state->carry; | |
111 | state->carry = dot_scrt(state->idx, ++(state->off)); | |
112 | } | |
113 | ||
114 | int amdtp_dot_set_parameters(struct amdtp_stream *s, unsigned int rate, | |
9dc5d31c | 115 | unsigned int pcm_channels) |
163ae6f3 TS |
116 | { |
117 | struct amdtp_dot *p = s->protocol; | |
118 | int err; | |
119 | ||
120 | if (amdtp_stream_running(s)) | |
121 | return -EBUSY; | |
122 | ||
123 | /* | |
8820a4cf TS |
124 | * A first data channel is for MIDI messages, the rest is Multi Bit |
125 | * Linear Audio data channel. | |
163ae6f3 TS |
126 | */ |
127 | err = amdtp_stream_set_parameters(s, rate, pcm_channels + 1); | |
128 | if (err < 0) | |
129 | return err; | |
130 | ||
131 | s->fdf = AMDTP_FDF_AM824 | s->sfc; | |
132 | ||
133 | p->pcm_channels = pcm_channels; | |
9dc5d31c | 134 | |
9dc5d31c TS |
135 | /* |
136 | * We do not know the actual MIDI FIFO size of most devices. Just | |
137 | * assume two bytes, i.e., one byte can be received over the bus while | |
138 | * the previous one is transmitted over MIDI. | |
139 | * (The value here is adjusted for midi_ratelimit_per_packet().) | |
140 | */ | |
141 | p->midi_fifo_limit = rate - MIDI_BYTES_PER_SECOND * s->syt_interval + 1; | |
163ae6f3 TS |
142 | |
143 | return 0; | |
144 | } | |
145 | ||
146 | static void write_pcm_s32(struct amdtp_stream *s, struct snd_pcm_substream *pcm, | |
147 | __be32 *buffer, unsigned int frames) | |
148 | { | |
149 | struct amdtp_dot *p = s->protocol; | |
150 | struct snd_pcm_runtime *runtime = pcm->runtime; | |
151 | unsigned int channels, remaining_frames, i, c; | |
152 | const u32 *src; | |
153 | ||
154 | channels = p->pcm_channels; | |
155 | src = (void *)runtime->dma_area + | |
156 | frames_to_bytes(runtime, s->pcm_buffer_pointer); | |
157 | remaining_frames = runtime->buffer_size - s->pcm_buffer_pointer; | |
158 | ||
159 | buffer++; | |
160 | for (i = 0; i < frames; ++i) { | |
161 | for (c = 0; c < channels; ++c) { | |
162 | buffer[c] = cpu_to_be32((*src >> 8) | 0x40000000); | |
163 | dot_encode_step(&p->state, &buffer[c]); | |
164 | src++; | |
165 | } | |
166 | buffer += s->data_block_quadlets; | |
167 | if (--remaining_frames == 0) | |
168 | src = (void *)runtime->dma_area; | |
169 | } | |
170 | } | |
171 | ||
163ae6f3 TS |
172 | static void read_pcm_s32(struct amdtp_stream *s, struct snd_pcm_substream *pcm, |
173 | __be32 *buffer, unsigned int frames) | |
174 | { | |
175 | struct amdtp_dot *p = s->protocol; | |
176 | struct snd_pcm_runtime *runtime = pcm->runtime; | |
177 | unsigned int channels, remaining_frames, i, c; | |
178 | u32 *dst; | |
179 | ||
180 | channels = p->pcm_channels; | |
181 | dst = (void *)runtime->dma_area + | |
182 | frames_to_bytes(runtime, s->pcm_buffer_pointer); | |
183 | remaining_frames = runtime->buffer_size - s->pcm_buffer_pointer; | |
184 | ||
185 | buffer++; | |
186 | for (i = 0; i < frames; ++i) { | |
187 | for (c = 0; c < channels; ++c) { | |
188 | *dst = be32_to_cpu(buffer[c]) << 8; | |
189 | dst++; | |
190 | } | |
191 | buffer += s->data_block_quadlets; | |
192 | if (--remaining_frames == 0) | |
193 | dst = (void *)runtime->dma_area; | |
194 | } | |
195 | } | |
196 | ||
197 | static void write_pcm_silence(struct amdtp_stream *s, __be32 *buffer, | |
198 | unsigned int data_blocks) | |
199 | { | |
200 | struct amdtp_dot *p = s->protocol; | |
201 | unsigned int channels, i, c; | |
202 | ||
203 | channels = p->pcm_channels; | |
204 | ||
205 | buffer++; | |
206 | for (i = 0; i < data_blocks; ++i) { | |
207 | for (c = 0; c < channels; ++c) | |
208 | buffer[c] = cpu_to_be32(0x40000000); | |
209 | buffer += s->data_block_quadlets; | |
210 | } | |
211 | } | |
212 | ||
9dc5d31c TS |
213 | static bool midi_ratelimit_per_packet(struct amdtp_stream *s, unsigned int port) |
214 | { | |
215 | struct amdtp_dot *p = s->protocol; | |
216 | int used; | |
217 | ||
218 | used = p->midi_fifo_used[port]; | |
219 | if (used == 0) | |
220 | return true; | |
221 | ||
222 | used -= MIDI_BYTES_PER_SECOND * s->syt_interval; | |
223 | used = max(used, 0); | |
224 | p->midi_fifo_used[port] = used; | |
225 | ||
226 | return used < p->midi_fifo_limit; | |
227 | } | |
228 | ||
229 | static inline void midi_use_bytes(struct amdtp_stream *s, | |
230 | unsigned int port, unsigned int count) | |
231 | { | |
232 | struct amdtp_dot *p = s->protocol; | |
233 | ||
234 | p->midi_fifo_used[port] += amdtp_rate_table[s->sfc] * count; | |
235 | } | |
236 | ||
237 | static void write_midi_messages(struct amdtp_stream *s, __be32 *buffer, | |
238 | unsigned int data_blocks) | |
239 | { | |
240 | struct amdtp_dot *p = s->protocol; | |
241 | unsigned int f, port; | |
242 | int len; | |
243 | u8 *b; | |
244 | ||
245 | for (f = 0; f < data_blocks; f++) { | |
246 | port = (s->data_block_counter + f) % 8; | |
247 | b = (u8 *)&buffer[0]; | |
248 | ||
249 | len = 0; | |
8820a4cf | 250 | if (port < MAX_MIDI_PORTS && |
9dc5d31c TS |
251 | midi_ratelimit_per_packet(s, port) && |
252 | p->midi[port] != NULL) | |
253 | len = snd_rawmidi_transmit(p->midi[port], b + 1, 2); | |
254 | ||
255 | if (len > 0) { | |
8820a4cf TS |
256 | /* |
257 | * Upper 4 bits of LSB represent port number. | |
258 | * - 0000b: physical MIDI port 1. | |
259 | * - 0010b: physical MIDI port 2. | |
260 | * - 1110b: console MIDI port. | |
261 | */ | |
262 | if (port == 2) | |
263 | b[3] = 0xe0; | |
264 | else if (port == 1) | |
265 | b[3] = 0x20; | |
266 | else | |
267 | b[3] = 0x00; | |
268 | b[3] |= len; | |
9dc5d31c TS |
269 | midi_use_bytes(s, port, len); |
270 | } else { | |
271 | b[1] = 0; | |
272 | b[2] = 0; | |
273 | b[3] = 0; | |
274 | } | |
275 | b[0] = 0x80; | |
276 | ||
277 | buffer += s->data_block_quadlets; | |
278 | } | |
279 | } | |
280 | ||
281 | static void read_midi_messages(struct amdtp_stream *s, __be32 *buffer, | |
282 | unsigned int data_blocks) | |
283 | { | |
284 | struct amdtp_dot *p = s->protocol; | |
285 | unsigned int f, port, len; | |
286 | u8 *b; | |
287 | ||
288 | for (f = 0; f < data_blocks; f++) { | |
289 | b = (u8 *)&buffer[0]; | |
9dc5d31c | 290 | |
8820a4cf TS |
291 | len = b[3] & 0x0f; |
292 | if (len > 0) { | |
293 | /* | |
294 | * Upper 4 bits of LSB represent port number. | |
295 | * - 0000b: physical MIDI port 1. Use port 0. | |
296 | * - 1110b: console MIDI port. Use port 2. | |
297 | */ | |
298 | if (b[3] >> 4 > 0) | |
299 | port = 2; | |
300 | else | |
301 | port = 0; | |
302 | ||
303 | if (port < MAX_MIDI_PORTS && p->midi[port]) | |
304 | snd_rawmidi_receive(p->midi[port], b + 1, len); | |
305 | } | |
9dc5d31c TS |
306 | |
307 | buffer += s->data_block_quadlets; | |
308 | } | |
309 | } | |
310 | ||
163ae6f3 TS |
311 | int amdtp_dot_add_pcm_hw_constraints(struct amdtp_stream *s, |
312 | struct snd_pcm_runtime *runtime) | |
313 | { | |
314 | int err; | |
315 | ||
316 | /* This protocol delivers 24 bit data in 32bit data channel. */ | |
317 | err = snd_pcm_hw_constraint_msbits(runtime, 0, 32, 24); | |
318 | if (err < 0) | |
319 | return err; | |
320 | ||
321 | return amdtp_stream_add_pcm_hw_constraints(s, runtime); | |
322 | } | |
323 | ||
9dc5d31c TS |
324 | void amdtp_dot_midi_trigger(struct amdtp_stream *s, unsigned int port, |
325 | struct snd_rawmidi_substream *midi) | |
326 | { | |
327 | struct amdtp_dot *p = s->protocol; | |
328 | ||
8820a4cf | 329 | if (port < MAX_MIDI_PORTS) |
6aa7de05 | 330 | WRITE_ONCE(p->midi[port], midi); |
9dc5d31c TS |
331 | } |
332 | ||
163ae6f3 TS |
333 | static unsigned int process_tx_data_blocks(struct amdtp_stream *s, |
334 | __be32 *buffer, | |
335 | unsigned int data_blocks, | |
336 | unsigned int *syt) | |
337 | { | |
163ae6f3 TS |
338 | struct snd_pcm_substream *pcm; |
339 | unsigned int pcm_frames; | |
340 | ||
6aa7de05 | 341 | pcm = READ_ONCE(s->pcm); |
163ae6f3 | 342 | if (pcm) { |
a02cb8f8 | 343 | read_pcm_s32(s, pcm, buffer, data_blocks); |
163ae6f3 TS |
344 | pcm_frames = data_blocks; |
345 | } else { | |
346 | pcm_frames = 0; | |
347 | } | |
348 | ||
9dc5d31c | 349 | read_midi_messages(s, buffer, data_blocks); |
163ae6f3 TS |
350 | |
351 | return pcm_frames; | |
352 | } | |
353 | ||
354 | static unsigned int process_rx_data_blocks(struct amdtp_stream *s, | |
355 | __be32 *buffer, | |
356 | unsigned int data_blocks, | |
357 | unsigned int *syt) | |
358 | { | |
163ae6f3 TS |
359 | struct snd_pcm_substream *pcm; |
360 | unsigned int pcm_frames; | |
361 | ||
6aa7de05 | 362 | pcm = READ_ONCE(s->pcm); |
163ae6f3 | 363 | if (pcm) { |
a02cb8f8 | 364 | write_pcm_s32(s, pcm, buffer, data_blocks); |
163ae6f3 TS |
365 | pcm_frames = data_blocks; |
366 | } else { | |
367 | write_pcm_silence(s, buffer, data_blocks); | |
368 | pcm_frames = 0; | |
369 | } | |
370 | ||
9dc5d31c | 371 | write_midi_messages(s, buffer, data_blocks); |
163ae6f3 TS |
372 | |
373 | return pcm_frames; | |
374 | } | |
375 | ||
376 | int amdtp_dot_init(struct amdtp_stream *s, struct fw_unit *unit, | |
377 | enum amdtp_stream_direction dir) | |
378 | { | |
379 | amdtp_stream_process_data_blocks_t process_data_blocks; | |
380 | enum cip_flags flags; | |
381 | ||
382 | /* Use different mode between incoming/outgoing. */ | |
383 | if (dir == AMDTP_IN_STREAM) { | |
62f00e40 | 384 | flags = CIP_NONBLOCKING; |
163ae6f3 TS |
385 | process_data_blocks = process_tx_data_blocks; |
386 | } else { | |
387 | flags = CIP_BLOCKING; | |
388 | process_data_blocks = process_rx_data_blocks; | |
389 | } | |
390 | ||
391 | return amdtp_stream_init(s, unit, dir, flags, CIP_FMT_AM, | |
392 | process_data_blocks, sizeof(struct amdtp_dot)); | |
393 | } | |
394 | ||
395 | void amdtp_dot_reset(struct amdtp_stream *s) | |
396 | { | |
397 | struct amdtp_dot *p = s->protocol; | |
398 | ||
399 | p->state.carry = 0x00; | |
400 | p->state.idx = 0x00; | |
401 | p->state.off = 0; | |
402 | } |