xref: /openbmc/linux/sound/firewire/motu/amdtp-motu.c (revision b830f94f)
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,
121 			 struct snd_pcm_runtime *runtime,
122 			 __be32 *buffer, unsigned int data_blocks)
123 {
124 	struct amdtp_motu *p = s->protocol;
125 	unsigned int channels, remaining_frames, i, c;
126 	u8 *byte;
127 	u32 *dst;
128 
129 	channels = p->pcm_chunks;
130 	dst = (void *)runtime->dma_area +
131 			frames_to_bytes(runtime, s->pcm_buffer_pointer);
132 	remaining_frames = runtime->buffer_size - s->pcm_buffer_pointer;
133 
134 	for (i = 0; i < data_blocks; ++i) {
135 		byte = (u8 *)buffer + p->pcm_byte_offset;
136 
137 		for (c = 0; c < channels; ++c) {
138 			*dst = (byte[0] << 24) |
139 			       (byte[1] << 16) |
140 			       (byte[2] << 8);
141 			byte += 3;
142 			dst++;
143 		}
144 		buffer += s->data_block_quadlets;
145 		if (--remaining_frames == 0)
146 			dst = (void *)runtime->dma_area;
147 	}
148 }
149 
150 static void write_pcm_s32(struct amdtp_stream *s,
151 			  struct snd_pcm_runtime *runtime,
152 			  __be32 *buffer, unsigned int data_blocks)
153 {
154 	struct amdtp_motu *p = s->protocol;
155 	unsigned int channels, remaining_frames, i, c;
156 	u8 *byte;
157 	const u32 *src;
158 
159 	channels = p->pcm_chunks;
160 	src = (void *)runtime->dma_area +
161 			frames_to_bytes(runtime, s->pcm_buffer_pointer);
162 	remaining_frames = runtime->buffer_size - s->pcm_buffer_pointer;
163 
164 	for (i = 0; i < data_blocks; ++i) {
165 		byte = (u8 *)buffer + p->pcm_byte_offset;
166 
167 		for (c = 0; c < channels; ++c) {
168 			byte[0] = (*src >> 24) & 0xff;
169 			byte[1] = (*src >> 16) & 0xff;
170 			byte[2] = (*src >>  8) & 0xff;
171 			byte += 3;
172 			src++;
173 		}
174 
175 		buffer += s->data_block_quadlets;
176 		if (--remaining_frames == 0)
177 			src = (void *)runtime->dma_area;
178 	}
179 }
180 
181 static void write_pcm_silence(struct amdtp_stream *s, __be32 *buffer,
182 			      unsigned int data_blocks)
183 {
184 	struct amdtp_motu *p = s->protocol;
185 	unsigned int channels, i, c;
186 	u8 *byte;
187 
188 	channels = p->pcm_chunks;
189 
190 	for (i = 0; i < data_blocks; ++i) {
191 		byte = (u8 *)buffer + p->pcm_byte_offset;
192 
193 		for (c = 0; c < channels; ++c) {
194 			byte[0] = 0;
195 			byte[1] = 0;
196 			byte[2] = 0;
197 			byte += 3;
198 		}
199 
200 		buffer += s->data_block_quadlets;
201 	}
202 }
203 
204 int amdtp_motu_add_pcm_hw_constraints(struct amdtp_stream *s,
205 				      struct snd_pcm_runtime *runtime)
206 {
207 	int err;
208 
209 	/* TODO: how to set an constraint for exactly 24bit PCM sample? */
210 	err = snd_pcm_hw_constraint_msbits(runtime, 0, 32, 24);
211 	if (err < 0)
212 		return err;
213 
214 	return amdtp_stream_add_pcm_hw_constraints(s, runtime);
215 }
216 
217 void amdtp_motu_midi_trigger(struct amdtp_stream *s, unsigned int port,
218 			     struct snd_rawmidi_substream *midi)
219 {
220 	struct amdtp_motu *p = s->protocol;
221 
222 	if (port < p->midi_ports)
223 		WRITE_ONCE(p->midi, midi);
224 }
225 
226 static void write_midi_messages(struct amdtp_stream *s, __be32 *buffer,
227 				unsigned int data_blocks)
228 {
229 	struct amdtp_motu *p = s->protocol;
230 	struct snd_rawmidi_substream *midi = READ_ONCE(p->midi);
231 	u8 *b;
232 	int i;
233 
234 	for (i = 0; i < data_blocks; i++) {
235 		b = (u8 *)buffer;
236 
237 		if (midi && p->midi_db_count == 0 &&
238 		    snd_rawmidi_transmit(midi, b + p->midi_byte_offset, 1) == 1) {
239 			b[p->midi_flag_offset] = 0x01;
240 		} else {
241 			b[p->midi_byte_offset] = 0x00;
242 			b[p->midi_flag_offset] = 0x00;
243 		}
244 
245 		buffer += s->data_block_quadlets;
246 
247 		if (--p->midi_db_count < 0)
248 			p->midi_db_count = p->midi_db_interval;
249 	}
250 }
251 
252 static void read_midi_messages(struct amdtp_stream *s, __be32 *buffer,
253 			       unsigned int data_blocks)
254 {
255 	struct amdtp_motu *p = s->protocol;
256 	struct snd_rawmidi_substream *midi;
257 	u8 *b;
258 	int i;
259 
260 	for (i = 0; i < data_blocks; i++) {
261 		b = (u8 *)buffer;
262 		midi = READ_ONCE(p->midi);
263 
264 		if (midi && (b[p->midi_flag_offset] & 0x01))
265 			snd_rawmidi_receive(midi, b + p->midi_byte_offset, 1);
266 
267 		buffer += s->data_block_quadlets;
268 	}
269 }
270 
271 /* For tracepoints. */
272 static void __maybe_unused copy_sph(u32 *frames, __be32 *buffer,
273 				    unsigned int data_blocks,
274 				    unsigned int data_block_quadlets)
275 {
276 	unsigned int i;
277 
278 	for (i = 0; i < data_blocks; ++i) {
279 		*frames = be32_to_cpu(*buffer);
280 		buffer += data_block_quadlets;
281 		frames++;
282 	}
283 }
284 
285 /* For tracepoints. */
286 static void __maybe_unused copy_message(u64 *frames, __be32 *buffer,
287 					unsigned int data_blocks,
288 					unsigned int data_block_quadlets)
289 {
290 	unsigned int i;
291 
292 	/* This is just for v2/v3 protocol. */
293 	for (i = 0; i < data_blocks; ++i) {
294 		*frames = (be32_to_cpu(buffer[1]) << 16) |
295 			  (be32_to_cpu(buffer[2]) >> 16);
296 		buffer += data_block_quadlets;
297 		frames++;
298 	}
299 }
300 
301 static unsigned int process_tx_data_blocks(struct amdtp_stream *s,
302 				__be32 *buffer, unsigned int data_blocks,
303 				unsigned int *syt)
304 {
305 	struct amdtp_motu *p = s->protocol;
306 	struct snd_pcm_substream *pcm;
307 
308 	trace_data_block_sph(s, data_blocks, buffer);
309 	trace_data_block_message(s, data_blocks, buffer);
310 
311 	if (p->midi_ports)
312 		read_midi_messages(s, buffer, data_blocks);
313 
314 	pcm = READ_ONCE(s->pcm);
315 	if (data_blocks > 0 && pcm)
316 		read_pcm_s32(s, pcm->runtime, buffer, data_blocks);
317 
318 	return data_blocks;
319 }
320 
321 static inline void compute_next_elapse_from_start(struct amdtp_motu *p)
322 {
323 	p->next_accumulated += p->remainder_ticks_per_event;
324 	if (p->next_accumulated >= 441) {
325 		p->next_accumulated -= 441;
326 		p->next_ticks++;
327 	}
328 
329 	p->next_ticks += p->quotient_ticks_per_event;
330 	if (p->next_ticks >= 3072) {
331 		p->next_ticks -= 3072;
332 		p->next_cycles++;
333 	}
334 
335 	if (p->next_cycles >= 8000) {
336 		p->next_cycles -= 8000;
337 		p->next_seconds++;
338 	}
339 
340 	if (p->next_seconds >= 128)
341 		p->next_seconds -= 128;
342 }
343 
344 static void write_sph(struct amdtp_stream *s, __be32 *buffer,
345 		      unsigned int data_blocks)
346 {
347 	struct amdtp_motu *p = s->protocol;
348 	unsigned int next_cycles;
349 	unsigned int i;
350 	u32 sph;
351 
352 	for (i = 0; i < data_blocks; i++) {
353 		next_cycles = (s->start_cycle + p->next_cycles) % 8000;
354 		sph = ((next_cycles << 12) | p->next_ticks) & 0x01ffffff;
355 		*buffer = cpu_to_be32(sph);
356 
357 		compute_next_elapse_from_start(p);
358 
359 		buffer += s->data_block_quadlets;
360 	}
361 }
362 
363 static unsigned int process_rx_data_blocks(struct amdtp_stream *s,
364 				__be32 *buffer, unsigned int data_blocks,
365 				unsigned int *syt)
366 {
367 	struct amdtp_motu *p = (struct amdtp_motu *)s->protocol;
368 	struct snd_pcm_substream *pcm;
369 
370 	/* Not used. */
371 	*syt = 0xffff;
372 
373 	/* TODO: how to interact control messages between userspace? */
374 
375 	if (p->midi_ports)
376 		write_midi_messages(s, buffer, data_blocks);
377 
378 	pcm = READ_ONCE(s->pcm);
379 	if (pcm)
380 		write_pcm_s32(s, pcm->runtime, buffer, data_blocks);
381 	else
382 		write_pcm_silence(s, buffer, data_blocks);
383 
384 	write_sph(s, buffer, data_blocks);
385 
386 	trace_data_block_sph(s, data_blocks, buffer);
387 	trace_data_block_message(s, data_blocks, buffer);
388 
389 	return data_blocks;
390 }
391 
392 int amdtp_motu_init(struct amdtp_stream *s, struct fw_unit *unit,
393 		    enum amdtp_stream_direction dir,
394 		    const struct snd_motu_protocol *const protocol)
395 {
396 	amdtp_stream_process_data_blocks_t process_data_blocks;
397 	int fmt = CIP_FMT_MOTU;
398 	int flags = CIP_BLOCKING;
399 	int err;
400 
401 	if (dir == AMDTP_IN_STREAM) {
402 		process_data_blocks = process_tx_data_blocks;
403 
404 		/*
405 		 * Units of version 3 transmits packets with invalid CIP header
406 		 * against IEC 61883-1.
407 		 */
408 		if (protocol == &snd_motu_protocol_v3) {
409 			flags |= CIP_WRONG_DBS |
410 				 CIP_SKIP_DBC_ZERO_CHECK |
411 				 CIP_HEADER_WITHOUT_EOH;
412 			fmt = CIP_FMT_MOTU_TX_V3;
413 		}
414 
415 		if (protocol == &snd_motu_protocol_v2) {
416 			// 8pre has some quirks.
417 			flags |= CIP_WRONG_DBS |
418 				 CIP_SKIP_DBC_ZERO_CHECK;
419 		}
420 	} else {
421 		process_data_blocks = process_rx_data_blocks;
422 		flags |= CIP_DBC_IS_END_EVENT;
423 	}
424 
425 	err = amdtp_stream_init(s, unit, dir, flags, fmt, process_data_blocks,
426 				sizeof(struct amdtp_motu));
427 	if (err < 0)
428 		return err;
429 
430 	s->sph = 1;
431 	s->ctx_data.rx.fdf = MOTU_FDF_AM824;
432 
433 	return 0;
434 }
435