1 // SPDX-License-Identifier: GPL-2.0
2 // ff-protocol-latter - a part of driver for RME Fireface series
3 //
4 // Copyright (c) 2019 Takashi Sakamoto
5 //
6 // Licensed under the terms of the GNU General Public License, version 2.
7 
8 #include <linux/delay.h>
9 
10 #include "ff.h"
11 
12 #define LATTER_STF		0xffff00000004ULL
13 #define LATTER_ISOC_CHANNELS	0xffff00000008ULL
14 #define LATTER_ISOC_START	0xffff0000000cULL
15 #define LATTER_FETCH_MODE	0xffff00000010ULL
16 #define LATTER_SYNC_STATUS	0x0000801c0000ULL
17 
18 static int parse_clock_bits(u32 data, unsigned int *rate,
19 			    enum snd_ff_clock_src *src)
20 {
21 	static const struct {
22 		unsigned int rate;
23 		u32 flag;
24 	} *rate_entry, rate_entries[] = {
25 		{ 32000,	0x00000000, },
26 		{ 44100,	0x01000000, },
27 		{ 48000,	0x02000000, },
28 		{ 64000,	0x04000000, },
29 		{ 88200,	0x05000000, },
30 		{ 96000,	0x06000000, },
31 		{ 128000,	0x08000000, },
32 		{ 176400,	0x09000000, },
33 		{ 192000,	0x0a000000, },
34 	};
35 	static const struct {
36 		enum snd_ff_clock_src src;
37 		u32 flag;
38 	} *clk_entry, clk_entries[] = {
39 		{ SND_FF_CLOCK_SRC_SPDIF,	0x00000200, },
40 		{ SND_FF_CLOCK_SRC_ADAT1,	0x00000400, },
41 		{ SND_FF_CLOCK_SRC_WORD,	0x00000600, },
42 		{ SND_FF_CLOCK_SRC_INTERNAL,	0x00000e00, },
43 	};
44 	int i;
45 
46 	for (i = 0; i < ARRAY_SIZE(rate_entries); ++i) {
47 		rate_entry = rate_entries + i;
48 		if ((data & 0x0f000000) == rate_entry->flag) {
49 			*rate = rate_entry->rate;
50 			break;
51 		}
52 	}
53 	if (i == ARRAY_SIZE(rate_entries))
54 		return -EIO;
55 
56 	for (i = 0; i < ARRAY_SIZE(clk_entries); ++i) {
57 		clk_entry = clk_entries + i;
58 		if ((data & 0x000e00) == clk_entry->flag) {
59 			*src = clk_entry->src;
60 			break;
61 		}
62 	}
63 	if (i == ARRAY_SIZE(clk_entries))
64 		return -EIO;
65 
66 	return 0;
67 }
68 
69 static int latter_get_clock(struct snd_ff *ff, unsigned int *rate,
70 			   enum snd_ff_clock_src *src)
71 {
72 	__le32 reg;
73 	u32 data;
74 	int err;
75 
76 	err = snd_fw_transaction(ff->unit, TCODE_READ_QUADLET_REQUEST,
77 				 LATTER_SYNC_STATUS, &reg, sizeof(reg), 0);
78 	if (err < 0)
79 		return err;
80 	data = le32_to_cpu(reg);
81 
82 	return parse_clock_bits(data, rate, src);
83 }
84 
85 static int latter_switch_fetching_mode(struct snd_ff *ff, bool enable)
86 {
87 	u32 data;
88 	__le32 reg;
89 
90 	if (enable)
91 		data = 0x00000000;
92 	else
93 		data = 0xffffffff;
94 	reg = cpu_to_le32(data);
95 
96 	return snd_fw_transaction(ff->unit, TCODE_WRITE_QUADLET_REQUEST,
97 				  LATTER_FETCH_MODE, &reg, sizeof(reg), 0);
98 }
99 
100 static int latter_allocate_resources(struct snd_ff *ff, unsigned int rate)
101 {
102 	enum snd_ff_stream_mode mode;
103 	unsigned int code;
104 	__le32 reg;
105 	unsigned int count;
106 	int i;
107 	int err;
108 
109 	// Set the number of data blocks transferred in a second.
110 	if (rate % 32000 == 0)
111 		code = 0x00;
112 	else if (rate % 44100 == 0)
113 		code = 0x02;
114 	else if (rate % 48000 == 0)
115 		code = 0x04;
116 	else
117 		return -EINVAL;
118 
119 	if (rate >= 64000 && rate < 128000)
120 		code |= 0x08;
121 	else if (rate >= 128000 && rate < 192000)
122 		code |= 0x10;
123 
124 	reg = cpu_to_le32(code);
125 	err = snd_fw_transaction(ff->unit, TCODE_WRITE_QUADLET_REQUEST,
126 				 LATTER_STF, &reg, sizeof(reg), 0);
127 	if (err < 0)
128 		return err;
129 
130 	// Confirm to shift transmission clock.
131 	count = 0;
132 	while (count++ < 10) {
133 		unsigned int curr_rate;
134 		enum snd_ff_clock_src src;
135 
136 		err = latter_get_clock(ff, &curr_rate, &src);
137 		if (err < 0)
138 			return err;
139 
140 		if (curr_rate == rate)
141 			break;
142 	}
143 	if (count == 10)
144 		return -ETIMEDOUT;
145 
146 	for (i = 0; i < ARRAY_SIZE(amdtp_rate_table); ++i) {
147 		if (rate == amdtp_rate_table[i])
148 			break;
149 	}
150 	if (i == ARRAY_SIZE(amdtp_rate_table))
151 		return -EINVAL;
152 
153 	err = snd_ff_stream_get_multiplier_mode(i, &mode);
154 	if (err < 0)
155 		return err;
156 
157 	// Keep resources for in-stream.
158 	ff->tx_resources.channels_mask = 0x00000000000000ffuLL;
159 	err = fw_iso_resources_allocate(&ff->tx_resources,
160 			amdtp_stream_get_max_payload(&ff->tx_stream),
161 			fw_parent_device(ff->unit)->max_speed);
162 	if (err < 0)
163 		return err;
164 
165 	// Keep resources for out-stream.
166 	ff->rx_resources.channels_mask = 0x00000000000000ffuLL;
167 	err = fw_iso_resources_allocate(&ff->rx_resources,
168 			amdtp_stream_get_max_payload(&ff->rx_stream),
169 			fw_parent_device(ff->unit)->max_speed);
170 	if (err < 0)
171 		fw_iso_resources_free(&ff->tx_resources);
172 
173 	return err;
174 }
175 
176 static int latter_begin_session(struct snd_ff *ff, unsigned int rate)
177 {
178 	unsigned int generation = ff->rx_resources.generation;
179 	unsigned int flag;
180 	u32 data;
181 	__le32 reg;
182 	int err;
183 
184 	if (rate >= 32000 && rate <= 48000)
185 		flag = 0x92;
186 	else if (rate >= 64000 && rate <= 96000)
187 		flag = 0x8e;
188 	else if (rate >= 128000 && rate <= 192000)
189 		flag = 0x8c;
190 	else
191 		return -EINVAL;
192 
193 	if (generation != fw_parent_device(ff->unit)->card->generation) {
194 		err = fw_iso_resources_update(&ff->tx_resources);
195 		if (err < 0)
196 			return err;
197 
198 		err = fw_iso_resources_update(&ff->rx_resources);
199 		if (err < 0)
200 			return err;
201 	}
202 
203 	data = (ff->tx_resources.channel << 8) | ff->rx_resources.channel;
204 	reg = cpu_to_le32(data);
205 	err = snd_fw_transaction(ff->unit, TCODE_WRITE_QUADLET_REQUEST,
206 				 LATTER_ISOC_CHANNELS, &reg, sizeof(reg), 0);
207 	if (err < 0)
208 		return err;
209 
210 	// Always use the maximum number of data channels in data block of
211 	// packet.
212 	reg = cpu_to_le32(flag);
213 	return snd_fw_transaction(ff->unit, TCODE_WRITE_QUADLET_REQUEST,
214 				  LATTER_ISOC_START, &reg, sizeof(reg), 0);
215 }
216 
217 static void latter_finish_session(struct snd_ff *ff)
218 {
219 	__le32 reg;
220 
221 	reg = cpu_to_le32(0x00000000);
222 	snd_fw_transaction(ff->unit, TCODE_WRITE_QUADLET_REQUEST,
223 			   LATTER_ISOC_START, &reg, sizeof(reg), 0);
224 }
225 
226 static void latter_dump_status(struct snd_ff *ff, struct snd_info_buffer *buffer)
227 {
228 	static const struct {
229 		char *const label;
230 		u32 locked_mask;
231 		u32 synced_mask;
232 	} *clk_entry, clk_entries[] = {
233 		{ "S/PDIF",	0x00000001, 0x00000010, },
234 		{ "ADAT",	0x00000002, 0x00000020, },
235 		{ "WDClk",	0x00000004, 0x00000040, },
236 	};
237 	__le32 reg;
238 	u32 data;
239 	unsigned int rate;
240 	enum snd_ff_clock_src src;
241 	const char *label;
242 	int i;
243 	int err;
244 
245 	err = snd_fw_transaction(ff->unit, TCODE_READ_QUADLET_REQUEST,
246 				 LATTER_SYNC_STATUS, &reg, sizeof(reg), 0);
247 	if (err < 0)
248 		return;
249 	data = le32_to_cpu(reg);
250 
251 	snd_iprintf(buffer, "External source detection:\n");
252 
253 	for (i = 0; i < ARRAY_SIZE(clk_entries); ++i) {
254 		clk_entry = clk_entries + i;
255 		snd_iprintf(buffer, "%s: ", clk_entry->label);
256 		if (data & clk_entry->locked_mask) {
257 			if (data & clk_entry->synced_mask)
258 				snd_iprintf(buffer, "sync\n");
259 			else
260 				snd_iprintf(buffer, "lock\n");
261 		} else {
262 			snd_iprintf(buffer, "none\n");
263 		}
264 	}
265 
266 	err = parse_clock_bits(data, &rate, &src);
267 	if (err < 0)
268 		return;
269 	label = snd_ff_proc_get_clk_label(src);
270 	if (!label)
271 		return;
272 
273 	snd_iprintf(buffer, "Referred clock: %s %d\n", label, rate);
274 }
275 
276 // NOTE: transactions are transferred within 0x00-0x7f in allocated range of
277 // address. This seems to be for check of discontinuity in receiver side.
278 //
279 // Like Fireface 400, drivers can select one of 4 options for lower 4 bytes of
280 // destination address by bit flags in quadlet register (little endian) at
281 // 0x'ffff'0000'0014:
282 //
283 // bit flags: offset of destination address
284 // - 0x00002000: 0x'....'....'0000'0000
285 // - 0x00004000: 0x'....'....'0000'0080
286 // - 0x00008000: 0x'....'....'0000'0100
287 // - 0x00010000: 0x'....'....'0000'0180
288 //
289 // Drivers can suppress the device to transfer asynchronous transactions by
290 // clear these bit flags.
291 //
292 // Actually, the register is write-only and includes the other settings such as
293 // input attenuation. This driver allocates for the first option
294 // (0x'....'....'0000'0000) and expects userspace application to configure the
295 // register for it.
296 static void latter_handle_midi_msg(struct snd_ff *ff, unsigned int offset,
297 				   __le32 *buf, size_t length)
298 {
299 	u32 data = le32_to_cpu(*buf);
300 	unsigned int index = (data & 0x000000f0) >> 4;
301 	u8 byte[3];
302 	struct snd_rawmidi_substream *substream;
303 	unsigned int len;
304 
305 	if (index >= ff->spec->midi_in_ports)
306 		return;
307 
308 	switch (data & 0x0000000f) {
309 	case 0x00000008:
310 	case 0x00000009:
311 	case 0x0000000a:
312 	case 0x0000000b:
313 	case 0x0000000e:
314 		len = 3;
315 		break;
316 	case 0x0000000c:
317 	case 0x0000000d:
318 		len = 2;
319 		break;
320 	default:
321 		len = data & 0x00000003;
322 		if (len == 0)
323 			len = 3;
324 		break;
325 	}
326 
327 	byte[0] = (data & 0x0000ff00) >> 8;
328 	byte[1] = (data & 0x00ff0000) >> 16;
329 	byte[2] = (data & 0xff000000) >> 24;
330 
331 	substream = READ_ONCE(ff->tx_midi_substreams[index]);
332 	if (substream)
333 		snd_rawmidi_receive(substream, byte, len);
334 }
335 
336 /*
337  * When return minus value, given argument is not MIDI status.
338  * When return 0, given argument is a beginning of system exclusive.
339  * When return the others, given argument is MIDI data.
340  */
341 static inline int calculate_message_bytes(u8 status)
342 {
343 	switch (status) {
344 	case 0xf6:	/* Tune request. */
345 	case 0xf8:	/* Timing clock. */
346 	case 0xfa:	/* Start. */
347 	case 0xfb:	/* Continue. */
348 	case 0xfc:	/* Stop. */
349 	case 0xfe:	/* Active sensing. */
350 	case 0xff:	/* System reset. */
351 		return 1;
352 	case 0xf1:	/* MIDI time code quarter frame. */
353 	case 0xf3:	/* Song select. */
354 		return 2;
355 	case 0xf2:	/* Song position pointer. */
356 		return 3;
357 	case 0xf0:	/* Exclusive. */
358 		return 0;
359 	case 0xf7:	/* End of exclusive. */
360 		break;
361 	case 0xf4:	/* Undefined. */
362 	case 0xf5:	/* Undefined. */
363 	case 0xf9:	/* Undefined. */
364 	case 0xfd:	/* Undefined. */
365 		break;
366 	default:
367 		switch (status & 0xf0) {
368 		case 0x80:	/* Note on. */
369 		case 0x90:	/* Note off. */
370 		case 0xa0:	/* Polyphonic key pressure. */
371 		case 0xb0:	/* Control change and Mode change. */
372 		case 0xe0:	/* Pitch bend change. */
373 			return 3;
374 		case 0xc0:	/* Program change. */
375 		case 0xd0:	/* Channel pressure. */
376 			return 2;
377 		default:
378 		break;
379 		}
380 	break;
381 	}
382 
383 	return -EINVAL;
384 }
385 
386 static int latter_fill_midi_msg(struct snd_ff *ff,
387 				struct snd_rawmidi_substream *substream,
388 				unsigned int port)
389 {
390 	u32 data = {0};
391 	u8 *buf = (u8 *)&data;
392 	int consumed;
393 
394 	buf[0] = port << 4;
395 	consumed = snd_rawmidi_transmit_peek(substream, buf + 1, 3);
396 	if (consumed <= 0)
397 		return consumed;
398 
399 	if (!ff->on_sysex[port]) {
400 		if (buf[1] != 0xf0) {
401 			if (consumed < calculate_message_bytes(buf[1]))
402 				return 0;
403 		} else {
404 			// The beginning of exclusives.
405 			ff->on_sysex[port] = true;
406 		}
407 
408 		buf[0] |= consumed;
409 	} else {
410 		if (buf[1] != 0xf7) {
411 			if (buf[2] == 0xf7 || buf[3] == 0xf7) {
412 				// Transfer end code at next time.
413 				consumed -= 1;
414 			}
415 
416 			buf[0] |= consumed;
417 		} else {
418 			// The end of exclusives.
419 			ff->on_sysex[port] = false;
420 			consumed = 1;
421 			buf[0] |= 0x0f;
422 		}
423 	}
424 
425 	ff->msg_buf[port][0] = cpu_to_le32(data);
426 	ff->rx_bytes[port] = consumed;
427 
428 	return 1;
429 }
430 
431 const struct snd_ff_protocol snd_ff_protocol_latter = {
432 	.handle_midi_msg	= latter_handle_midi_msg,
433 	.fill_midi_msg		= latter_fill_midi_msg,
434 	.get_clock		= latter_get_clock,
435 	.switch_fetching_mode	= latter_switch_fetching_mode,
436 	.allocate_resources	= latter_allocate_resources,
437 	.begin_session		= latter_begin_session,
438 	.finish_session		= latter_finish_session,
439 	.dump_status		= latter_dump_status,
440 };
441