xref: /linux/sound/firewire/motu/amdtp-motu.c (revision 6fdcba32711044c35c0e1b094cbd8f3f0b4472c9)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * amdtp-motu.c - a part of driver for MOTU FireWire series
4  *
5  * Copyright (c) 2015-2017 Takashi Sakamoto <o-takashi@sakamocchi.jp>
6  */
7 
8 #include <linux/slab.h>
9 #include <sound/pcm.h>
10 #include "motu.h"
11 
12 #define CREATE_TRACE_POINTS
13 #include "amdtp-motu-trace.h"
14 
15 #define CIP_FMT_MOTU		0x02
16 #define CIP_FMT_MOTU_TX_V3	0x22
17 #define MOTU_FDF_AM824		0x22
18 
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 struct amdtp_motu {
26 	/* For timestamp processing.  */
27 	unsigned int quotient_ticks_per_event;
28 	unsigned int remainder_ticks_per_event;
29 	unsigned int next_ticks;
30 	unsigned int next_accumulated;
31 	unsigned int next_cycles;
32 	unsigned int next_seconds;
33 
34 	unsigned int pcm_chunks;
35 	unsigned int pcm_byte_offset;
36 
37 	struct snd_rawmidi_substream *midi;
38 	unsigned int midi_ports;
39 	unsigned int midi_flag_offset;
40 	unsigned int midi_byte_offset;
41 
42 	int midi_db_count;
43 	unsigned int midi_db_interval;
44 };
45 
46 int amdtp_motu_set_parameters(struct amdtp_stream *s, unsigned int rate,
47 			      unsigned int midi_ports,
48 			      struct snd_motu_packet_format *formats)
49 {
50 	static const struct {
51 		unsigned int quotient_ticks_per_event;
52 		unsigned int remainder_ticks_per_event;
53 	} params[] = {
54 		[CIP_SFC_44100]  = { 557, 123 },
55 		[CIP_SFC_48000]  = { 512,   0 },
56 		[CIP_SFC_88200]  = { 278, 282 },
57 		[CIP_SFC_96000]  = { 256,   0 },
58 		[CIP_SFC_176400] = { 139, 141 },
59 		[CIP_SFC_192000] = { 128,   0 },
60 	};
61 	struct amdtp_motu *p = s->protocol;
62 	unsigned int pcm_chunks, data_chunks, data_block_quadlets;
63 	unsigned int delay;
64 	unsigned int mode;
65 	int i, err;
66 
67 	if (amdtp_stream_running(s))
68 		return -EBUSY;
69 
70 	for (i = 0; i < ARRAY_SIZE(snd_motu_clock_rates); ++i) {
71 		if (snd_motu_clock_rates[i] == rate) {
72 			mode = i >> 1;
73 			break;
74 		}
75 	}
76 	if (i == ARRAY_SIZE(snd_motu_clock_rates))
77 		return -EINVAL;
78 
79 	pcm_chunks = formats->fixed_part_pcm_chunks[mode] +
80 		     formats->differed_part_pcm_chunks[mode];
81 	data_chunks = formats->msg_chunks + pcm_chunks;
82 
83 	/*
84 	 * Each data block includes SPH in its head. Data chunks follow with
85 	 * 3 byte alignment. Padding follows with zero to conform to quadlet
86 	 * alignment.
87 	 */
88 	data_block_quadlets = 1 + DIV_ROUND_UP(data_chunks * 3, 4);
89 
90 	err = amdtp_stream_set_parameters(s, rate, data_block_quadlets);
91 	if (err < 0)
92 		return err;
93 
94 	p->pcm_chunks = pcm_chunks;
95 	p->pcm_byte_offset = formats->pcm_byte_offset;
96 
97 	p->midi_ports = midi_ports;
98 	p->midi_flag_offset = formats->midi_flag_offset;
99 	p->midi_byte_offset = formats->midi_byte_offset;
100 
101 	p->midi_db_count = 0;
102 	p->midi_db_interval = rate / MIDI_BYTES_PER_SECOND;
103 
104 	/* IEEE 1394 bus requires. */
105 	delay = 0x2e00;
106 
107 	/* For no-data or empty packets to adjust PCM sampling frequency. */
108 	delay += 8000 * 3072 * s->syt_interval / rate;
109 
110 	p->next_seconds = 0;
111 	p->next_cycles = delay / 3072;
112 	p->quotient_ticks_per_event = params[s->sfc].quotient_ticks_per_event;
113 	p->remainder_ticks_per_event = params[s->sfc].remainder_ticks_per_event;
114 	p->next_ticks = delay % 3072;
115 	p->next_accumulated = 0;
116 
117 	return 0;
118 }
119 
120 static void read_pcm_s32(struct amdtp_stream *s, struct snd_pcm_substream *pcm,
121 			 __be32 *buffer, unsigned int data_blocks,
122 			 unsigned int pcm_frames)
123 {
124 	struct amdtp_motu *p = s->protocol;
125 	unsigned int channels = p->pcm_chunks;
126 	struct snd_pcm_runtime *runtime = pcm->runtime;
127 	unsigned int pcm_buffer_pointer;
128 	int remaining_frames;
129 	u8 *byte;
130 	u32 *dst;
131 	int i, c;
132 
133 	pcm_buffer_pointer = s->pcm_buffer_pointer + pcm_frames;
134 	pcm_buffer_pointer %= runtime->buffer_size;
135 
136 	dst = (void *)runtime->dma_area +
137 				frames_to_bytes(runtime, pcm_buffer_pointer);
138 	remaining_frames = runtime->buffer_size - pcm_buffer_pointer;
139 
140 	for (i = 0; i < data_blocks; ++i) {
141 		byte = (u8 *)buffer + p->pcm_byte_offset;
142 
143 		for (c = 0; c < channels; ++c) {
144 			*dst = (byte[0] << 24) |
145 			       (byte[1] << 16) |
146 			       (byte[2] << 8);
147 			byte += 3;
148 			dst++;
149 		}
150 		buffer += s->data_block_quadlets;
151 		if (--remaining_frames == 0)
152 			dst = (void *)runtime->dma_area;
153 	}
154 }
155 
156 static void write_pcm_s32(struct amdtp_stream *s, struct snd_pcm_substream *pcm,
157 			  __be32 *buffer, unsigned int data_blocks,
158 			  unsigned int pcm_frames)
159 {
160 	struct amdtp_motu *p = s->protocol;
161 	unsigned int channels = p->pcm_chunks;
162 	struct snd_pcm_runtime *runtime = pcm->runtime;
163 	unsigned int pcm_buffer_pointer;
164 	int remaining_frames;
165 	u8 *byte;
166 	const u32 *src;
167 	int i, c;
168 
169 	pcm_buffer_pointer = s->pcm_buffer_pointer + pcm_frames;
170 	pcm_buffer_pointer %= runtime->buffer_size;
171 
172 	src = (void *)runtime->dma_area +
173 				frames_to_bytes(runtime, pcm_buffer_pointer);
174 	remaining_frames = runtime->buffer_size - pcm_buffer_pointer;
175 
176 	for (i = 0; i < data_blocks; ++i) {
177 		byte = (u8 *)buffer + p->pcm_byte_offset;
178 
179 		for (c = 0; c < channels; ++c) {
180 			byte[0] = (*src >> 24) & 0xff;
181 			byte[1] = (*src >> 16) & 0xff;
182 			byte[2] = (*src >>  8) & 0xff;
183 			byte += 3;
184 			src++;
185 		}
186 
187 		buffer += s->data_block_quadlets;
188 		if (--remaining_frames == 0)
189 			src = (void *)runtime->dma_area;
190 	}
191 }
192 
193 static void write_pcm_silence(struct amdtp_stream *s, __be32 *buffer,
194 			      unsigned int data_blocks)
195 {
196 	struct amdtp_motu *p = s->protocol;
197 	unsigned int channels, i, c;
198 	u8 *byte;
199 
200 	channels = p->pcm_chunks;
201 
202 	for (i = 0; i < data_blocks; ++i) {
203 		byte = (u8 *)buffer + p->pcm_byte_offset;
204 
205 		for (c = 0; c < channels; ++c) {
206 			byte[0] = 0;
207 			byte[1] = 0;
208 			byte[2] = 0;
209 			byte += 3;
210 		}
211 
212 		buffer += s->data_block_quadlets;
213 	}
214 }
215 
216 int amdtp_motu_add_pcm_hw_constraints(struct amdtp_stream *s,
217 				      struct snd_pcm_runtime *runtime)
218 {
219 	int err;
220 
221 	/* TODO: how to set an constraint for exactly 24bit PCM sample? */
222 	err = snd_pcm_hw_constraint_msbits(runtime, 0, 32, 24);
223 	if (err < 0)
224 		return err;
225 
226 	return amdtp_stream_add_pcm_hw_constraints(s, runtime);
227 }
228 
229 void amdtp_motu_midi_trigger(struct amdtp_stream *s, unsigned int port,
230 			     struct snd_rawmidi_substream *midi)
231 {
232 	struct amdtp_motu *p = s->protocol;
233 
234 	if (port < p->midi_ports)
235 		WRITE_ONCE(p->midi, midi);
236 }
237 
238 static void write_midi_messages(struct amdtp_stream *s, __be32 *buffer,
239 				unsigned int data_blocks)
240 {
241 	struct amdtp_motu *p = s->protocol;
242 	struct snd_rawmidi_substream *midi = READ_ONCE(p->midi);
243 	u8 *b;
244 	int i;
245 
246 	for (i = 0; i < data_blocks; i++) {
247 		b = (u8 *)buffer;
248 
249 		if (midi && p->midi_db_count == 0 &&
250 		    snd_rawmidi_transmit(midi, b + p->midi_byte_offset, 1) == 1) {
251 			b[p->midi_flag_offset] = 0x01;
252 		} else {
253 			b[p->midi_byte_offset] = 0x00;
254 			b[p->midi_flag_offset] = 0x00;
255 		}
256 
257 		buffer += s->data_block_quadlets;
258 
259 		if (--p->midi_db_count < 0)
260 			p->midi_db_count = p->midi_db_interval;
261 	}
262 }
263 
264 static void read_midi_messages(struct amdtp_stream *s, __be32 *buffer,
265 			       unsigned int data_blocks)
266 {
267 	struct amdtp_motu *p = s->protocol;
268 	struct snd_rawmidi_substream *midi;
269 	u8 *b;
270 	int i;
271 
272 	for (i = 0; i < data_blocks; i++) {
273 		b = (u8 *)buffer;
274 		midi = READ_ONCE(p->midi);
275 
276 		if (midi && (b[p->midi_flag_offset] & 0x01))
277 			snd_rawmidi_receive(midi, b + p->midi_byte_offset, 1);
278 
279 		buffer += s->data_block_quadlets;
280 	}
281 }
282 
283 /* For tracepoints. */
284 static void __maybe_unused copy_sph(u32 *frames, __be32 *buffer,
285 				    unsigned int data_blocks,
286 				    unsigned int data_block_quadlets)
287 {
288 	unsigned int i;
289 
290 	for (i = 0; i < data_blocks; ++i) {
291 		*frames = be32_to_cpu(*buffer);
292 		buffer += data_block_quadlets;
293 		frames++;
294 	}
295 }
296 
297 /* For tracepoints. */
298 static void __maybe_unused copy_message(u64 *frames, __be32 *buffer,
299 					unsigned int data_blocks,
300 					unsigned int data_block_quadlets)
301 {
302 	unsigned int i;
303 
304 	/* This is just for v2/v3 protocol. */
305 	for (i = 0; i < data_blocks; ++i) {
306 		*frames = (be32_to_cpu(buffer[1]) << 16) |
307 			  (be32_to_cpu(buffer[2]) >> 16);
308 		buffer += data_block_quadlets;
309 		frames++;
310 	}
311 }
312 
313 static void probe_tracepoints_events(struct amdtp_stream *s,
314 				     const struct pkt_desc *descs,
315 				     unsigned int packets)
316 {
317 	int i;
318 
319 	for (i = 0; i < packets; ++i) {
320 		const struct pkt_desc *desc = descs + i;
321 		__be32 *buf = desc->ctx_payload;
322 		unsigned int data_blocks = desc->data_blocks;
323 
324 		trace_data_block_sph(s, data_blocks, buf);
325 		trace_data_block_message(s, data_blocks, buf);
326 	}
327 }
328 
329 static unsigned int process_ir_ctx_payloads(struct amdtp_stream *s,
330 					    const struct pkt_desc *descs,
331 					    unsigned int packets,
332 					    struct snd_pcm_substream *pcm)
333 {
334 	struct amdtp_motu *p = s->protocol;
335 	unsigned int pcm_frames = 0;
336 	int i;
337 
338 	// For data block processing.
339 	for (i = 0; i < packets; ++i) {
340 		const struct pkt_desc *desc = descs + i;
341 		__be32 *buf = desc->ctx_payload;
342 		unsigned int data_blocks = desc->data_blocks;
343 
344 		if (pcm) {
345 			read_pcm_s32(s, pcm, buf, data_blocks, pcm_frames);
346 			pcm_frames += data_blocks;
347 		}
348 
349 		if (p->midi_ports)
350 			read_midi_messages(s, buf, data_blocks);
351 	}
352 
353 	// For tracepoints.
354 	if (trace_data_block_sph_enabled() ||
355 	    trace_data_block_message_enabled())
356 		probe_tracepoints_events(s, descs, packets);
357 
358 	return pcm_frames;
359 }
360 
361 static inline void compute_next_elapse_from_start(struct amdtp_motu *p)
362 {
363 	p->next_accumulated += p->remainder_ticks_per_event;
364 	if (p->next_accumulated >= 441) {
365 		p->next_accumulated -= 441;
366 		p->next_ticks++;
367 	}
368 
369 	p->next_ticks += p->quotient_ticks_per_event;
370 	if (p->next_ticks >= 3072) {
371 		p->next_ticks -= 3072;
372 		p->next_cycles++;
373 	}
374 
375 	if (p->next_cycles >= 8000) {
376 		p->next_cycles -= 8000;
377 		p->next_seconds++;
378 	}
379 
380 	if (p->next_seconds >= 128)
381 		p->next_seconds -= 128;
382 }
383 
384 static void write_sph(struct amdtp_stream *s, __be32 *buffer,
385 		      unsigned int data_blocks)
386 {
387 	struct amdtp_motu *p = s->protocol;
388 	unsigned int next_cycles;
389 	unsigned int i;
390 	u32 sph;
391 
392 	for (i = 0; i < data_blocks; i++) {
393 		next_cycles = (s->start_cycle + p->next_cycles) % 8000;
394 		sph = ((next_cycles << 12) | p->next_ticks) & 0x01ffffff;
395 		*buffer = cpu_to_be32(sph);
396 
397 		compute_next_elapse_from_start(p);
398 
399 		buffer += s->data_block_quadlets;
400 	}
401 }
402 
403 static unsigned int process_it_ctx_payloads(struct amdtp_stream *s,
404 					    const struct pkt_desc *descs,
405 					    unsigned int packets,
406 					    struct snd_pcm_substream *pcm)
407 {
408 	struct amdtp_motu *p = s->protocol;
409 	unsigned int pcm_frames = 0;
410 	int i;
411 
412 	// For data block processing.
413 	for (i = 0; i < packets; ++i) {
414 		const struct pkt_desc *desc = descs + i;
415 		__be32 *buf = desc->ctx_payload;
416 		unsigned int data_blocks = desc->data_blocks;
417 
418 		if (pcm) {
419 			write_pcm_s32(s, pcm, buf, data_blocks, pcm_frames);
420 			pcm_frames += data_blocks;
421 		} else {
422 			write_pcm_silence(s, buf, data_blocks);
423 		}
424 
425 		if (p->midi_ports)
426 			write_midi_messages(s, buf, data_blocks);
427 
428 		// TODO: how to interact control messages between userspace?
429 
430 		write_sph(s, buf, data_blocks);
431 	}
432 
433 	// For tracepoints.
434 	if (trace_data_block_sph_enabled() ||
435 	    trace_data_block_message_enabled())
436 		probe_tracepoints_events(s, descs, packets);
437 
438 	return pcm_frames;
439 }
440 
441 int amdtp_motu_init(struct amdtp_stream *s, struct fw_unit *unit,
442 		    enum amdtp_stream_direction dir,
443 		    const struct snd_motu_protocol *const protocol)
444 {
445 	amdtp_stream_process_ctx_payloads_t process_ctx_payloads;
446 	int fmt = CIP_FMT_MOTU;
447 	int flags = CIP_BLOCKING;
448 	int err;
449 
450 	if (dir == AMDTP_IN_STREAM) {
451 		process_ctx_payloads = process_ir_ctx_payloads;
452 
453 		/*
454 		 * Units of version 3 transmits packets with invalid CIP header
455 		 * against IEC 61883-1.
456 		 */
457 		if (protocol == &snd_motu_protocol_v3) {
458 			flags |= CIP_WRONG_DBS |
459 				 CIP_SKIP_DBC_ZERO_CHECK |
460 				 CIP_HEADER_WITHOUT_EOH;
461 			fmt = CIP_FMT_MOTU_TX_V3;
462 		}
463 
464 		if (protocol == &snd_motu_protocol_v2) {
465 			// 8pre has some quirks.
466 			flags |= CIP_WRONG_DBS |
467 				 CIP_SKIP_DBC_ZERO_CHECK;
468 		}
469 	} else {
470 		process_ctx_payloads = process_it_ctx_payloads;
471 		flags |= CIP_DBC_IS_END_EVENT;
472 	}
473 
474 	err = amdtp_stream_init(s, unit, dir, flags, fmt, process_ctx_payloads,
475 				sizeof(struct amdtp_motu));
476 	if (err < 0)
477 		return err;
478 
479 	s->sph = 1;
480 
481 	if (dir == AMDTP_OUT_STREAM) {
482 		// Use fixed value for FDF field.
483 		s->ctx_data.rx.fdf = MOTU_FDF_AM824;
484 		// Not used.
485 		s->ctx_data.rx.syt_override = 0xffff;
486 	}
487 
488 	return 0;
489 }
490