xref: /linux/sound/firewire/fireface/ff-protocol-former.c (revision ea68a3e9d14e9e0bf017d178fb4bd53b6deb1482)
1 // SPDX-License-Identifier: GPL-2.0
2 // ff-protocol-former.c - a part of driver for RME Fireface series
3 //
4 // Copyright (c) 2019 Takashi Sakamoto
5 
6 #include <linux/delay.h>
7 
8 #include "ff.h"
9 
10 #define FORMER_REG_SYNC_STATUS		0x0000801c0000ull
11 /* For block write request. */
12 #define FORMER_REG_FETCH_PCM_FRAMES	0x0000801c0000ull
13 #define FORMER_REG_CLOCK_CONFIG		0x0000801c0004ull
14 
15 static int parse_clock_bits(u32 data, unsigned int *rate,
16 			    enum snd_ff_clock_src *src)
17 {
18 	static const struct {
19 		unsigned int rate;
20 		u32 mask;
21 	} *rate_entry, rate_entries[] = {
22 		{  32000, 0x00000002, },
23 		{  44100, 0x00000000, },
24 		{  48000, 0x00000006, },
25 		{  64000, 0x0000000a, },
26 		{  88200, 0x00000008, },
27 		{  96000, 0x0000000e, },
28 		{ 128000, 0x00000012, },
29 		{ 176400, 0x00000010, },
30 		{ 192000, 0x00000016, },
31 	};
32 	static const struct {
33 		enum snd_ff_clock_src src;
34 		u32 mask;
35 	} *clk_entry, clk_entries[] = {
36 		{ SND_FF_CLOCK_SRC_ADAT1,	0x00000000, },
37 		{ SND_FF_CLOCK_SRC_ADAT2,	0x00000400, },
38 		{ SND_FF_CLOCK_SRC_SPDIF,	0x00000c00, },
39 		{ SND_FF_CLOCK_SRC_WORD,	0x00001000, },
40 		{ SND_FF_CLOCK_SRC_LTC,		0x00001800, },
41 	};
42 	int i;
43 
44 	for (i = 0; i < ARRAY_SIZE(rate_entries); ++i) {
45 		rate_entry = rate_entries + i;
46 		if ((data & 0x0000001e) == rate_entry->mask) {
47 			*rate = rate_entry->rate;
48 			break;
49 		}
50 	}
51 	if (i == ARRAY_SIZE(rate_entries))
52 		return -EIO;
53 
54 	if (data & 0x00000001) {
55 		*src = SND_FF_CLOCK_SRC_INTERNAL;
56 	} else {
57 		for (i = 0; i < ARRAY_SIZE(clk_entries); ++i) {
58 			clk_entry = clk_entries + i;
59 			if ((data & 0x00001c00) == clk_entry->mask) {
60 				*src = clk_entry->src;
61 				break;
62 			}
63 		}
64 		if (i == ARRAY_SIZE(clk_entries))
65 			return -EIO;
66 	}
67 
68 	return 0;
69 }
70 
71 static int former_get_clock(struct snd_ff *ff, unsigned int *rate,
72 			    enum snd_ff_clock_src *src)
73 {
74 	__le32 reg;
75 	u32 data;
76 	int err;
77 
78 	err = snd_fw_transaction(ff->unit, TCODE_READ_QUADLET_REQUEST,
79 				 FORMER_REG_CLOCK_CONFIG, &reg, sizeof(reg), 0);
80 	if (err < 0)
81 		return err;
82 	data = le32_to_cpu(reg);
83 
84 	return parse_clock_bits(data, rate, src);
85 }
86 
87 static int former_switch_fetching_mode(struct snd_ff *ff, bool enable)
88 {
89 	unsigned int count;
90 	__le32 *reg;
91 	int i;
92 	int err;
93 
94 	count = 0;
95 	for (i = 0; i < SND_FF_STREAM_MODE_COUNT; ++i)
96 		count = max(count, ff->spec->pcm_playback_channels[i]);
97 
98 	reg = kcalloc(count, sizeof(__le32), GFP_KERNEL);
99 	if (!reg)
100 		return -ENOMEM;
101 
102 	if (!enable) {
103 		/*
104 		 * Each quadlet is corresponding to data channels in a data
105 		 * blocks in reverse order. Precisely, quadlets for available
106 		 * data channels should be enabled. Here, I take second best
107 		 * to fetch PCM frames from all of data channels regardless of
108 		 * stf.
109 		 */
110 		for (i = 0; i < count; ++i)
111 			reg[i] = cpu_to_le32(0x00000001);
112 	}
113 
114 	err = snd_fw_transaction(ff->unit, TCODE_WRITE_BLOCK_REQUEST,
115 				 FORMER_REG_FETCH_PCM_FRAMES, reg,
116 				 sizeof(__le32) * count, 0);
117 	kfree(reg);
118 	return err;
119 }
120 
121 static void dump_clock_config(struct snd_ff *ff, struct snd_info_buffer *buffer)
122 {
123 	__le32 reg;
124 	u32 data;
125 	unsigned int rate;
126 	enum snd_ff_clock_src src;
127 	const char *label;
128 	int err;
129 
130 	err = snd_fw_transaction(ff->unit, TCODE_READ_BLOCK_REQUEST,
131 				 FORMER_REG_CLOCK_CONFIG, &reg, sizeof(reg), 0);
132 	if (err < 0)
133 		return;
134 	data = le32_to_cpu(reg);
135 
136 	snd_iprintf(buffer, "Output S/PDIF format: %s (Emphasis: %s)\n",
137 		    (data & 0x00000020) ? "Professional" : "Consumer",
138 		    (data & 0x00000040) ? "on" : "off");
139 
140 	snd_iprintf(buffer, "Optical output interface format: %s\n",
141 		    (data & 0x00000100) ? "S/PDIF" : "ADAT");
142 
143 	snd_iprintf(buffer, "Word output single speed: %s\n",
144 		    (data & 0x00002000) ? "on" : "off");
145 
146 	snd_iprintf(buffer, "S/PDIF input interface: %s\n",
147 		    (data & 0x00000200) ? "Optical" : "Coaxial");
148 
149 	err = parse_clock_bits(data, &rate, &src);
150 	if (err < 0)
151 		return;
152 	label = snd_ff_proc_get_clk_label(src);
153 	if (!label)
154 		return;
155 
156 	snd_iprintf(buffer, "Clock configuration: %d %s\n", rate, label);
157 }
158 
159 static void dump_sync_status(struct snd_ff *ff, struct snd_info_buffer *buffer)
160 {
161 	static const struct {
162 		char *const label;
163 		u32 locked_mask;
164 		u32 synced_mask;
165 	} *clk_entry, clk_entries[] = {
166 		{ "WDClk",	0x40000000, 0x20000000, },
167 		{ "S/PDIF",	0x00080000, 0x00040000, },
168 		{ "ADAT1",	0x00000400, 0x00001000, },
169 		{ "ADAT2",	0x00000800, 0x00002000, },
170 	};
171 	static const struct {
172 		char *const label;
173 		u32 mask;
174 	} *referred_entry, referred_entries[] = {
175 		{ "ADAT1",	0x00000000, },
176 		{ "ADAT2",	0x00400000, },
177 		{ "S/PDIF",	0x00c00000, },
178 		{ "WDclk",	0x01000000, },
179 		{ "TCO",	0x01400000, },
180 	};
181 	static const struct {
182 		unsigned int rate;
183 		u32 mask;
184 	} *rate_entry, rate_entries[] = {
185 		{ 32000,	0x02000000, },
186 		{ 44100,	0x04000000, },
187 		{ 48000,	0x06000000, },
188 		{ 64000,	0x08000000, },
189 		{ 88200,	0x0a000000, },
190 		{ 96000,	0x0c000000, },
191 		{ 128000,	0x0e000000, },
192 		{ 176400,	0x10000000, },
193 		{ 192000,	0x12000000, },
194 	};
195 	__le32 reg[2];
196 	u32 data[2];
197 	int i;
198 	int err;
199 
200 	err = snd_fw_transaction(ff->unit, TCODE_READ_BLOCK_REQUEST,
201 				 FORMER_REG_SYNC_STATUS, reg, sizeof(reg), 0);
202 	if (err < 0)
203 		return;
204 	data[0] = le32_to_cpu(reg[0]);
205 	data[1] = le32_to_cpu(reg[1]);
206 
207 	snd_iprintf(buffer, "External source detection:\n");
208 
209 	for (i = 0; i < ARRAY_SIZE(clk_entries); ++i) {
210 		const char *state;
211 
212 		clk_entry = clk_entries + i;
213 		if (data[0] & clk_entry->locked_mask) {
214 			if (data[0] & clk_entry->synced_mask)
215 				state = "sync";
216 			else
217 				state = "lock";
218 		} else {
219 			state = "none";
220 		}
221 
222 		snd_iprintf(buffer, "%s: %s\n", clk_entry->label, state);
223 	}
224 
225 	snd_iprintf(buffer, "Referred clock:\n");
226 
227 	if (data[1] & 0x00000001) {
228 		snd_iprintf(buffer, "Internal\n");
229 	} else {
230 		unsigned int rate;
231 		const char *label;
232 
233 		for (i = 0; i < ARRAY_SIZE(referred_entries); ++i) {
234 			referred_entry = referred_entries + i;
235 			if ((data[0] & 0x1e0000) == referred_entry->mask) {
236 				label = referred_entry->label;
237 				break;
238 			}
239 		}
240 		if (i == ARRAY_SIZE(referred_entries))
241 			label = "none";
242 
243 		for (i = 0; i < ARRAY_SIZE(rate_entries); ++i) {
244 			rate_entry = rate_entries + i;
245 			if ((data[0] & 0x1e000000) == rate_entry->mask) {
246 				rate = rate_entry->rate;
247 				break;
248 			}
249 		}
250 		if (i == ARRAY_SIZE(rate_entries))
251 			rate = 0;
252 
253 		snd_iprintf(buffer, "%s %d\n", label, rate);
254 	}
255 }
256 
257 static void former_dump_status(struct snd_ff *ff,
258 			       struct snd_info_buffer *buffer)
259 {
260 	dump_clock_config(ff, buffer);
261 	dump_sync_status(ff, buffer);
262 }
263 
264 static int former_fill_midi_msg(struct snd_ff *ff,
265 				struct snd_rawmidi_substream *substream,
266 				unsigned int port)
267 {
268 	u8 *buf = (u8 *)ff->msg_buf[port];
269 	int len;
270 	int i;
271 
272 	len = snd_rawmidi_transmit_peek(substream, buf,
273 					SND_FF_MAXIMIM_MIDI_QUADS);
274 	if (len <= 0)
275 		return len;
276 
277 	// One quadlet includes one byte.
278 	for (i = len - 1; i >= 0; --i)
279 		ff->msg_buf[port][i] = cpu_to_le32(buf[i]);
280 	ff->rx_bytes[port] = len;
281 
282 	return len;
283 }
284 
285 #define FF800_STF		0x0000fc88f000
286 #define FF800_RX_PACKET_FORMAT	0x0000fc88f004
287 #define FF800_ALLOC_TX_STREAM	0x0000fc88f008
288 #define FF800_ISOC_COMM_START	0x0000fc88f00c
289 #define   FF800_TX_S800_FLAG	0x00000800
290 #define FF800_ISOC_COMM_STOP	0x0000fc88f010
291 
292 #define FF800_TX_PACKET_ISOC_CH	0x0000801c0008
293 
294 static int allocate_tx_resources(struct snd_ff *ff)
295 {
296 	__le32 reg;
297 	unsigned int count;
298 	unsigned int tx_isoc_channel;
299 	int err;
300 
301 	reg = cpu_to_le32(ff->tx_stream.data_block_quadlets);
302 	err = snd_fw_transaction(ff->unit, TCODE_WRITE_QUADLET_REQUEST,
303 				 FF800_ALLOC_TX_STREAM, &reg, sizeof(reg), 0);
304 	if (err < 0)
305 		return err;
306 
307 	// Wait till the format of tx packet is available.
308 	count = 0;
309 	while (count++ < 10) {
310 		u32 data;
311 		err = snd_fw_transaction(ff->unit, TCODE_READ_QUADLET_REQUEST,
312 				FF800_TX_PACKET_ISOC_CH, &reg, sizeof(reg), 0);
313 		if (err < 0)
314 			return err;
315 
316 		data = le32_to_cpu(reg);
317 		if (data != 0xffffffff) {
318 			tx_isoc_channel = data;
319 			break;
320 		}
321 
322 		msleep(50);
323 	}
324 	if (count >= 10)
325 		return -ETIMEDOUT;
326 
327 	// NOTE: this is a makeshift to start OHCI 1394 IR context in the
328 	// channel. On the other hand, 'struct fw_iso_resources.allocated' is
329 	// not true and it's not deallocated at stop.
330 	ff->tx_resources.channel = tx_isoc_channel;
331 
332 	return 0;
333 }
334 
335 static int ff800_allocate_resources(struct snd_ff *ff, unsigned int rate)
336 {
337 	u32 data;
338 	__le32 reg;
339 	int err;
340 
341 	reg = cpu_to_le32(rate);
342 	err = snd_fw_transaction(ff->unit, TCODE_WRITE_QUADLET_REQUEST,
343 				 FF800_STF, &reg, sizeof(reg), 0);
344 	if (err < 0)
345 		return err;
346 
347 	// If starting isochronous communication immediately, change of STF has
348 	// no effect. In this case, the communication runs based on former STF.
349 	// Let's sleep for a bit.
350 	msleep(100);
351 
352 	// Controllers should allocate isochronous resources for rx stream.
353 	err = fw_iso_resources_allocate(&ff->rx_resources,
354 				amdtp_stream_get_max_payload(&ff->rx_stream),
355 				fw_parent_device(ff->unit)->max_speed);
356 	if (err < 0)
357 		return err;
358 
359 	// Set isochronous channel and the number of quadlets of rx packets.
360 	// This should be done before the allocation of tx resources to avoid
361 	// periodical noise.
362 	data = ff->rx_stream.data_block_quadlets << 3;
363 	data = (data << 8) | ff->rx_resources.channel;
364 	reg = cpu_to_le32(data);
365 	err = snd_fw_transaction(ff->unit, TCODE_WRITE_QUADLET_REQUEST,
366 				 FF800_RX_PACKET_FORMAT, &reg, sizeof(reg), 0);
367 	if (err < 0)
368 		return err;
369 
370 	return allocate_tx_resources(ff);
371 }
372 
373 static int ff800_begin_session(struct snd_ff *ff, unsigned int rate)
374 {
375 	unsigned int generation = ff->rx_resources.generation;
376 	__le32 reg;
377 
378 	if (generation != fw_parent_device(ff->unit)->card->generation) {
379 		int err = fw_iso_resources_update(&ff->rx_resources);
380 		if (err < 0)
381 			return err;
382 	}
383 
384 	reg = cpu_to_le32(0x80000000);
385 	reg |= cpu_to_le32(ff->tx_stream.data_block_quadlets);
386 	if (fw_parent_device(ff->unit)->max_speed == SCODE_800)
387 		reg |= cpu_to_le32(FF800_TX_S800_FLAG);
388 	return snd_fw_transaction(ff->unit, TCODE_WRITE_QUADLET_REQUEST,
389 				 FF800_ISOC_COMM_START, &reg, sizeof(reg), 0);
390 }
391 
392 static void ff800_finish_session(struct snd_ff *ff)
393 {
394 	__le32 reg;
395 
396 	reg = cpu_to_le32(0x80000000);
397 	snd_fw_transaction(ff->unit, TCODE_WRITE_QUADLET_REQUEST,
398 			   FF800_ISOC_COMM_STOP, &reg, sizeof(reg), 0);
399 }
400 
401 // Fireface 800 doesn't allow drivers to register lower 4 bytes of destination
402 // address.
403 // A write transaction to clear registered higher 4 bytes of destination address
404 // has an effect to suppress asynchronous transaction from device.
405 static void ff800_handle_midi_msg(struct snd_ff *ff, unsigned int offset, const __le32 *buf,
406 				  size_t length, u32 tstamp)
407 {
408 	int i;
409 
410 	for (i = 0; i < length / 4; i++) {
411 		u8 byte = le32_to_cpu(buf[i]) & 0xff;
412 		struct snd_rawmidi_substream *substream;
413 
414 		substream = READ_ONCE(ff->tx_midi_substreams[0]);
415 		if (substream)
416 			snd_rawmidi_receive(substream, &byte, 1);
417 	}
418 }
419 
420 const struct snd_ff_protocol snd_ff_protocol_ff800 = {
421 	.handle_msg		= ff800_handle_midi_msg,
422 	.fill_midi_msg		= former_fill_midi_msg,
423 	.get_clock		= former_get_clock,
424 	.switch_fetching_mode	= former_switch_fetching_mode,
425 	.allocate_resources	= ff800_allocate_resources,
426 	.begin_session		= ff800_begin_session,
427 	.finish_session		= ff800_finish_session,
428 	.dump_status		= former_dump_status,
429 };
430 
431 #define FF400_STF		0x000080100500ull
432 #define FF400_RX_PACKET_FORMAT	0x000080100504ull
433 #define FF400_ISOC_COMM_START	0x000080100508ull
434 #define FF400_TX_PACKET_FORMAT	0x00008010050cull
435 #define FF400_ISOC_COMM_STOP	0x000080100510ull
436 
437 // Fireface 400 manages isochronous channel number in 3 bit field. Therefore,
438 // we can allocate between 0 and 7 channel.
439 static int ff400_allocate_resources(struct snd_ff *ff, unsigned int rate)
440 {
441 	__le32 reg;
442 	enum snd_ff_stream_mode mode;
443 	int i;
444 	int err;
445 
446 	// Check whether the given value is supported or not.
447 	for (i = 0; i < CIP_SFC_COUNT; i++) {
448 		if (amdtp_rate_table[i] == rate)
449 			break;
450 	}
451 	if (i >= CIP_SFC_COUNT)
452 		return -EINVAL;
453 
454 	// Set the number of data blocks transferred in a second.
455 	reg = cpu_to_le32(rate);
456 	err = snd_fw_transaction(ff->unit, TCODE_WRITE_QUADLET_REQUEST,
457 				 FF400_STF, &reg, sizeof(reg), 0);
458 	if (err < 0)
459 		return err;
460 
461 	msleep(100);
462 
463 	err = snd_ff_stream_get_multiplier_mode(i, &mode);
464 	if (err < 0)
465 		return err;
466 
467 	// Keep resources for in-stream.
468 	ff->tx_resources.channels_mask = 0x00000000000000ffuLL;
469 	err = fw_iso_resources_allocate(&ff->tx_resources,
470 			amdtp_stream_get_max_payload(&ff->tx_stream),
471 			fw_parent_device(ff->unit)->max_speed);
472 	if (err < 0)
473 		return err;
474 
475 	// Keep resources for out-stream.
476 	ff->rx_resources.channels_mask = 0x00000000000000ffuLL;
477 	err = fw_iso_resources_allocate(&ff->rx_resources,
478 			amdtp_stream_get_max_payload(&ff->rx_stream),
479 			fw_parent_device(ff->unit)->max_speed);
480 	if (err < 0)
481 		fw_iso_resources_free(&ff->tx_resources);
482 
483 	return err;
484 }
485 
486 static int ff400_begin_session(struct snd_ff *ff, unsigned int rate)
487 {
488 	unsigned int generation = ff->rx_resources.generation;
489 	__le32 reg;
490 	int err;
491 
492 	if (generation != fw_parent_device(ff->unit)->card->generation) {
493 		err = fw_iso_resources_update(&ff->tx_resources);
494 		if (err < 0)
495 			return err;
496 
497 		err = fw_iso_resources_update(&ff->rx_resources);
498 		if (err < 0)
499 			return err;
500 	}
501 
502 	// Set isochronous channel and the number of quadlets of received
503 	// packets.
504 	reg = cpu_to_le32(((ff->rx_stream.data_block_quadlets << 3) << 8) |
505 			  ff->rx_resources.channel);
506 	err = snd_fw_transaction(ff->unit, TCODE_WRITE_QUADLET_REQUEST,
507 				 FF400_RX_PACKET_FORMAT, &reg, sizeof(reg), 0);
508 	if (err < 0)
509 		return err;
510 
511 	// Set isochronous channel and the number of quadlets of transmitted
512 	// packet.
513 	// TODO: investigate the purpose of this 0x80.
514 	reg = cpu_to_le32((0x80 << 24) |
515 			  (ff->tx_resources.channel << 5) |
516 			  (ff->tx_stream.data_block_quadlets));
517 	err = snd_fw_transaction(ff->unit, TCODE_WRITE_QUADLET_REQUEST,
518 				 FF400_TX_PACKET_FORMAT, &reg, sizeof(reg), 0);
519 	if (err < 0)
520 		return err;
521 
522 	// Allow to transmit packets.
523 	reg = cpu_to_le32(0x00000001);
524 	return snd_fw_transaction(ff->unit, TCODE_WRITE_QUADLET_REQUEST,
525 				 FF400_ISOC_COMM_START, &reg, sizeof(reg), 0);
526 }
527 
528 static void ff400_finish_session(struct snd_ff *ff)
529 {
530 	__le32 reg;
531 
532 	reg = cpu_to_le32(0x80000000);
533 	snd_fw_transaction(ff->unit, TCODE_WRITE_QUADLET_REQUEST,
534 			   FF400_ISOC_COMM_STOP, &reg, sizeof(reg), 0);
535 }
536 
537 static void parse_midi_msg(struct snd_ff *ff, u32 quad, unsigned int port)
538 {
539 	struct snd_rawmidi_substream *substream = READ_ONCE(ff->tx_midi_substreams[port]);
540 
541 	if (substream != NULL) {
542 		u8 byte = (quad >> (16 * port)) & 0x000000ff;
543 
544 		snd_rawmidi_receive(substream, &byte, 1);
545 	}
546 }
547 
548 #define FF400_QUEUE_SIZE	32
549 
550 struct ff400_msg_parser {
551 	struct {
552 		u32 msg;
553 		u32 tstamp;
554 	} msgs[FF400_QUEUE_SIZE];
555 	size_t push_pos;
556 	size_t pull_pos;
557 };
558 
559 static bool ff400_has_msg(struct snd_ff *ff)
560 {
561 	struct ff400_msg_parser *parser = ff->msg_parser;
562 
563 	return (parser->push_pos != parser->pull_pos);
564 }
565 
566 // For Fireface 400, lower 4 bytes of destination address is configured by bit
567 // flag in quadlet register (little endian) at 0x'0000'801'0051c. Drivers can
568 // select one of 4 options:
569 //
570 // bit flags: offset of destination address
571 //  - 0x04000000: 0x'....'....'0000'0000
572 //  - 0x08000000: 0x'....'....'0000'0080
573 //  - 0x10000000: 0x'....'....'0000'0100
574 //  - 0x20000000: 0x'....'....'0000'0180
575 //
576 // Drivers can suppress the device to transfer asynchronous transactions by
577 // using below 2 bits.
578 //  - 0x01000000: suppress transmission
579 //  - 0x02000000: suppress transmission
580 //
581 // Actually, the register is write-only and includes the other options such as
582 // input attenuation. This driver allocates destination address with '0000'0000
583 // in its lower offset and expects userspace application to configure the
584 // register for it.
585 
586 // When the message is for signal level operation, the upper 4 bits in MSB expresses the pair of
587 // stereo physical port.
588 // - 0: Microphone input 0/1
589 // - 1: Line input 0/1
590 // - [2-4]: Line output 0-5
591 // - 5: Headphone output 0/1
592 // - 6: S/PDIF output 0/1
593 // - [7-10]: ADAT output 0-7
594 //
595 // The value of signal level can be detected by mask of 0x00fffc00. For signal level of microphone
596 // input:
597 //
598 // - 0:    0.0 dB
599 // - 10: +10.0 dB
600 // - 11: +11.0 dB
601 // - 12: +12.0 dB
602 // - ...
603 // - 63: +63.0 dB:
604 // - 64: +64.0 dB:
605 // - 65: +65.0 dB:
606 //
607 // For signal level of line input:
608 //
609 // - 0:  0.0 dB
610 // - 1: +0.5 dB
611 // - 2: +1.0 dB
612 // - 3: +1.5 dB
613 // - ...
614 // - 34: +17.0 dB:
615 // - 35: +17.5 dB:
616 // - 36: +18.0 dB:
617 //
618 // For signal level of any type of output:
619 //
620 // - 63: -infinite
621 // - 62: -58.0 dB
622 // - 61: -56.0 dB
623 // - 60: -54.0 dB
624 // - 59: -53.0 dB
625 // - 58: -52.0 dB
626 // - ...
627 // - 7: -1.0 dB
628 // - 6:  0.0 dB
629 // - 5: +1.0 dB
630 // - ...
631 // - 2: +4.0 dB
632 // - 1: +5.0 dB
633 // - 0: +6.0 dB
634 //
635 // When the message is not for signal level operation, it's for MIDI bytes. When matching to
636 // FF400_MSG_FLAG_IS_MIDI_PORT_0, one MIDI byte can be detected by mask of 0x000000ff. When
637 // matching to FF400_MSG_FLAG_IS_MIDI_PORT_1, one MIDI byte can be detected by mask of 0x00ff0000.
638 #define FF400_MSG_FLAG_IS_SIGNAL_LEVEL		0x04000000
639 #define  FF400_MSG_FLAG_IS_RIGHT_CHANNEL	0x08000000
640 #define  FF400_MSG_FLAG_IS_STEREO_PAIRED	0x02000000
641 #define  FF400_MSG_MASK_STEREO_PAIR		0xf0000000
642 #define  FF400_MSG_MASK_SIGNAL_LEVEL		0x00fffc00
643 #define FF400_MSG_FLAG_IS_MIDI_PORT_0		0x00000100
644 #define  FF400_MSG_MASK_MIDI_PORT_0		0x000000ff
645 #define FF400_MSG_FLAG_IS_MIDI_PORT_1		0x01000000
646 #define  FF400_MSG_MASK_MIDI_PORT_1		0x00ff0000
647 
648 static void ff400_handle_msg(struct snd_ff *ff, unsigned int offset, const __le32 *buf,
649 			     size_t length, u32 tstamp)
650 {
651 	bool need_hwdep_wake_up = false;
652 	int i;
653 
654 	for (i = 0; i < length / 4; i++) {
655 		u32 quad = le32_to_cpu(buf[i]);
656 
657 		if (quad & FF400_MSG_FLAG_IS_SIGNAL_LEVEL) {
658 			struct ff400_msg_parser *parser = ff->msg_parser;
659 
660 			parser->msgs[parser->push_pos].msg = quad;
661 			parser->msgs[parser->push_pos].tstamp = tstamp;
662 			++parser->push_pos;
663 			if (parser->push_pos >= FF400_QUEUE_SIZE)
664 				parser->push_pos = 0;
665 
666 			need_hwdep_wake_up = true;
667 		} else if (quad & FF400_MSG_FLAG_IS_MIDI_PORT_0) {
668 			parse_midi_msg(ff, quad, 0);
669 		} else if (quad & FF400_MSG_FLAG_IS_MIDI_PORT_1) {
670 			parse_midi_msg(ff, quad, 1);
671 		}
672 	}
673 
674 	if (need_hwdep_wake_up)
675 		wake_up(&ff->hwdep_wait);
676 }
677 
678 static long ff400_copy_msg_to_user(struct snd_ff *ff, char __user *buf, long count)
679 {
680 	struct snd_firewire_event_ff400_message ev = {
681 		.type = SNDRV_FIREWIRE_EVENT_FF400_MESSAGE,
682 		.message_count = 0,
683 	};
684 	struct ff400_msg_parser *parser = ff->msg_parser;
685 	long consumed = 0;
686 	long ret = 0;
687 
688 	if (count < sizeof(ev) || parser->pull_pos == parser->push_pos)
689 		return 0;
690 
691 	count -= sizeof(ev);
692 	consumed += sizeof(ev);
693 
694 	while (count >= sizeof(*parser->msgs) && parser->pull_pos != parser->push_pos) {
695 		spin_unlock_irq(&ff->lock);
696 		if (copy_to_user(buf + consumed, parser->msgs + parser->pull_pos,
697 				 sizeof(*parser->msgs)))
698 			ret = -EFAULT;
699 		spin_lock_irq(&ff->lock);
700 		if (ret)
701 			return ret;
702 
703 		++parser->pull_pos;
704 		if (parser->pull_pos >= FF400_QUEUE_SIZE)
705 			parser->pull_pos = 0;
706 		++ev.message_count;
707 		count -= sizeof(*parser->msgs);
708 		consumed += sizeof(*parser->msgs);
709 	}
710 
711 	spin_unlock_irq(&ff->lock);
712 	if (copy_to_user(buf, &ev, sizeof(ev)))
713 		ret = -EFAULT;
714 	spin_lock_irq(&ff->lock);
715 	if (ret)
716 		return ret;
717 
718 	return consumed;
719 }
720 
721 const struct snd_ff_protocol snd_ff_protocol_ff400 = {
722 	.msg_parser_size	= sizeof(struct ff400_msg_parser),
723 	.has_msg		= ff400_has_msg,
724 	.copy_msg_to_user	= ff400_copy_msg_to_user,
725 	.handle_msg		= ff400_handle_msg,
726 	.fill_midi_msg		= former_fill_midi_msg,
727 	.get_clock		= former_get_clock,
728 	.switch_fetching_mode	= former_switch_fetching_mode,
729 	.allocate_resources	= ff400_allocate_resources,
730 	.begin_session		= ff400_begin_session,
731 	.finish_session		= ff400_finish_session,
732 	.dump_status		= former_dump_status,
733 };
734