xref: /openbmc/linux/sound/firewire/oxfw/oxfw-scs1x.c (revision 234489ac)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * oxfw-scs1x.c - a part of driver for OXFW970/971 based devices
4  *
5  * Copyright (c) Clemens Ladisch <clemens@ladisch.de>
6  * Copyright (c) 2015 Takashi Sakamoto <o-takashi@sakamocchi.jp>
7  */
8 
9 #include "oxfw.h"
10 
11 #define HSS1394_ADDRESS			0xc007dedadadaULL
12 #define HSS1394_MAX_PACKET_SIZE		64
13 #define HSS1394_TAG_USER_DATA		0x00
14 #define HSS1394_TAG_CHANGE_ADDRESS	0xf1
15 
16 struct fw_scs1x {
17 	struct fw_address_handler hss_handler;
18 	u8 input_escape_count;
19 	struct snd_rawmidi_substream *input;
20 
21 	/* For MIDI playback. */
22 	struct snd_rawmidi_substream *output;
23 	bool output_idle;
24 	u8 output_status;
25 	u8 output_bytes;
26 	bool output_escaped;
27 	bool output_escape_high_nibble;
28 	struct work_struct work;
29 	wait_queue_head_t idle_wait;
30 	u8 buffer[HSS1394_MAX_PACKET_SIZE];
31 	bool transaction_running;
32 	struct fw_transaction transaction;
33 	unsigned int transaction_bytes;
34 	bool error;
35 	struct fw_device *fw_dev;
36 };
37 
38 static const u8 sysex_escape_prefix[] = {
39 	0xf0,			/* SysEx begin */
40 	0x00, 0x01, 0x60,	/* Stanton DJ */
41 	0x48, 0x53, 0x53,	/* "HSS" */
42 };
43 
44 static void midi_input_escaped_byte(struct snd_rawmidi_substream *stream,
45 				    u8 byte)
46 {
47 	u8 nibbles[2];
48 
49 	nibbles[0] = byte >> 4;
50 	nibbles[1] = byte & 0x0f;
51 	snd_rawmidi_receive(stream, nibbles, 2);
52 }
53 
54 static void midi_input_byte(struct fw_scs1x *scs,
55 			    struct snd_rawmidi_substream *stream, u8 byte)
56 {
57 	const u8 eox = 0xf7;
58 
59 	if (scs->input_escape_count > 0) {
60 		midi_input_escaped_byte(stream, byte);
61 		scs->input_escape_count--;
62 		if (scs->input_escape_count == 0)
63 			snd_rawmidi_receive(stream, &eox, sizeof(eox));
64 	} else if (byte == 0xf9) {
65 		snd_rawmidi_receive(stream, sysex_escape_prefix,
66 				    ARRAY_SIZE(sysex_escape_prefix));
67 		midi_input_escaped_byte(stream, 0x00);
68 		midi_input_escaped_byte(stream, 0xf9);
69 		scs->input_escape_count = 3;
70 	} else {
71 		snd_rawmidi_receive(stream, &byte, 1);
72 	}
73 }
74 
75 static void midi_input_packet(struct fw_scs1x *scs,
76 			      struct snd_rawmidi_substream *stream,
77 			      const u8 *data, unsigned int bytes)
78 {
79 	unsigned int i;
80 	const u8 eox = 0xf7;
81 
82 	if (data[0] == HSS1394_TAG_USER_DATA) {
83 		for (i = 1; i < bytes; ++i)
84 			midi_input_byte(scs, stream, data[i]);
85 	} else {
86 		snd_rawmidi_receive(stream, sysex_escape_prefix,
87 				    ARRAY_SIZE(sysex_escape_prefix));
88 		for (i = 0; i < bytes; ++i)
89 			midi_input_escaped_byte(stream, data[i]);
90 		snd_rawmidi_receive(stream, &eox, sizeof(eox));
91 	}
92 }
93 
94 static void handle_hss(struct fw_card *card, struct fw_request *request,
95 		       int tcode, int destination, int source, int generation,
96 		       unsigned long long offset, void *data, size_t length,
97 		       void *callback_data)
98 {
99 	struct fw_scs1x *scs = callback_data;
100 	struct snd_rawmidi_substream *stream;
101 	int rcode;
102 
103 	if (offset != scs->hss_handler.offset) {
104 		rcode = RCODE_ADDRESS_ERROR;
105 		goto end;
106 	}
107 	if (tcode != TCODE_WRITE_QUADLET_REQUEST &&
108 	    tcode != TCODE_WRITE_BLOCK_REQUEST) {
109 		rcode = RCODE_TYPE_ERROR;
110 		goto end;
111 	}
112 
113 	if (length >= 1) {
114 		stream = READ_ONCE(scs->input);
115 		if (stream)
116 			midi_input_packet(scs, stream, data, length);
117 	}
118 
119 	rcode = RCODE_COMPLETE;
120 end:
121 	fw_send_response(card, request, rcode);
122 }
123 
124 static void scs_write_callback(struct fw_card *card, int rcode,
125 			       void *data, size_t length, void *callback_data)
126 {
127 	struct fw_scs1x *scs = callback_data;
128 
129 	if (!rcode_is_permanent_error(rcode)) {
130 		/* Don't retry for this data. */
131 		if (rcode == RCODE_COMPLETE)
132 			scs->transaction_bytes = 0;
133 	} else {
134 		scs->error = true;
135 	}
136 
137 	scs->transaction_running = false;
138 	schedule_work(&scs->work);
139 }
140 
141 static bool is_valid_running_status(u8 status)
142 {
143 	return status >= 0x80 && status <= 0xef;
144 }
145 
146 static bool is_one_byte_cmd(u8 status)
147 {
148 	return status == 0xf6 ||
149 	       status >= 0xf8;
150 }
151 
152 static bool is_two_bytes_cmd(u8 status)
153 {
154 	return (status >= 0xc0 && status <= 0xdf) ||
155 	       status == 0xf1 ||
156 	       status == 0xf3;
157 }
158 
159 static bool is_three_bytes_cmd(u8 status)
160 {
161 	return (status >= 0x80 && status <= 0xbf) ||
162 	       (status >= 0xe0 && status <= 0xef) ||
163 	       status == 0xf2;
164 }
165 
166 static bool is_invalid_cmd(u8 status)
167 {
168 	return status == 0xf4 ||
169 	       status == 0xf5 ||
170 	       status == 0xf9 ||
171 	       status == 0xfd;
172 }
173 
174 static void scs_output_work(struct work_struct *work)
175 {
176 	struct fw_scs1x *scs = container_of(work, struct fw_scs1x, work);
177 	struct snd_rawmidi_substream *stream;
178 	unsigned int i;
179 	u8 byte;
180 	int generation;
181 
182 	if (scs->transaction_running)
183 		return;
184 
185 	stream = READ_ONCE(scs->output);
186 	if (!stream || scs->error) {
187 		scs->output_idle = true;
188 		wake_up(&scs->idle_wait);
189 		return;
190 	}
191 
192 	if (scs->transaction_bytes > 0)
193 		goto retry;
194 
195 	i = scs->output_bytes;
196 	for (;;) {
197 		if (snd_rawmidi_transmit(stream, &byte, 1) != 1) {
198 			scs->output_bytes = i;
199 			scs->output_idle = true;
200 			wake_up(&scs->idle_wait);
201 			return;
202 		}
203 		/*
204 		 * Convert from real MIDI to what I think the device expects (no
205 		 * running status, one command per packet, unescaped SysExs).
206 		 */
207 		if (scs->output_escaped && byte < 0x80) {
208 			if (scs->output_escape_high_nibble) {
209 				if (i < HSS1394_MAX_PACKET_SIZE) {
210 					scs->buffer[i] = byte << 4;
211 					scs->output_escape_high_nibble = false;
212 				}
213 			} else {
214 				scs->buffer[i++] |= byte & 0x0f;
215 				scs->output_escape_high_nibble = true;
216 			}
217 		} else if (byte < 0x80) {
218 			if (i == 1) {
219 				if (!is_valid_running_status(
220 							scs->output_status))
221 					continue;
222 				scs->buffer[0] = HSS1394_TAG_USER_DATA;
223 				scs->buffer[i++] = scs->output_status;
224 			}
225 			scs->buffer[i++] = byte;
226 			if ((i == 3 && is_two_bytes_cmd(scs->output_status)) ||
227 			    (i == 4 && is_three_bytes_cmd(scs->output_status)))
228 				break;
229 			if (i == 1 + ARRAY_SIZE(sysex_escape_prefix) &&
230 			    !memcmp(scs->buffer + 1, sysex_escape_prefix,
231 				    ARRAY_SIZE(sysex_escape_prefix))) {
232 				scs->output_escaped = true;
233 				scs->output_escape_high_nibble = true;
234 				i = 0;
235 			}
236 			if (i >= HSS1394_MAX_PACKET_SIZE)
237 				i = 1;
238 		} else if (byte == 0xf7) {
239 			if (scs->output_escaped) {
240 				if (i >= 1 && scs->output_escape_high_nibble &&
241 				    scs->buffer[0] !=
242 						HSS1394_TAG_CHANGE_ADDRESS)
243 					break;
244 			} else {
245 				if (i > 1 && scs->output_status == 0xf0) {
246 					scs->buffer[i++] = 0xf7;
247 					break;
248 				}
249 			}
250 			i = 1;
251 			scs->output_escaped = false;
252 		} else if (!is_invalid_cmd(byte) && byte < 0xf8) {
253 			i = 1;
254 			scs->buffer[0] = HSS1394_TAG_USER_DATA;
255 			scs->buffer[i++] = byte;
256 			scs->output_status = byte;
257 			scs->output_escaped = false;
258 			if (is_one_byte_cmd(byte))
259 				break;
260 		}
261 	}
262 	scs->output_bytes = 1;
263 	scs->output_escaped = false;
264 
265 	scs->transaction_bytes = i;
266 retry:
267 	scs->transaction_running = true;
268 	generation = scs->fw_dev->generation;
269 	smp_rmb(); /* node_id vs. generation */
270 	fw_send_request(scs->fw_dev->card, &scs->transaction,
271 			TCODE_WRITE_BLOCK_REQUEST, scs->fw_dev->node_id,
272 			generation, scs->fw_dev->max_speed, HSS1394_ADDRESS,
273 			scs->buffer, scs->transaction_bytes,
274 			scs_write_callback, scs);
275 }
276 
277 static int midi_capture_open(struct snd_rawmidi_substream *stream)
278 {
279 	return 0;
280 }
281 
282 static int midi_capture_close(struct snd_rawmidi_substream *stream)
283 {
284 	return 0;
285 }
286 
287 static void midi_capture_trigger(struct snd_rawmidi_substream *stream, int up)
288 {
289 	struct fw_scs1x *scs = stream->rmidi->private_data;
290 
291 	if (up) {
292 		scs->input_escape_count = 0;
293 		WRITE_ONCE(scs->input, stream);
294 	} else {
295 		WRITE_ONCE(scs->input, NULL);
296 	}
297 }
298 
299 static int midi_playback_open(struct snd_rawmidi_substream *stream)
300 {
301 	return 0;
302 }
303 
304 static int midi_playback_close(struct snd_rawmidi_substream *stream)
305 {
306 	return 0;
307 }
308 
309 static void midi_playback_trigger(struct snd_rawmidi_substream *stream, int up)
310 {
311 	struct fw_scs1x *scs = stream->rmidi->private_data;
312 
313 	if (up) {
314 		scs->output_status = 0;
315 		scs->output_bytes = 1;
316 		scs->output_escaped = false;
317 		scs->output_idle = false;
318 		scs->transaction_bytes = 0;
319 		scs->error = false;
320 
321 		WRITE_ONCE(scs->output, stream);
322 		schedule_work(&scs->work);
323 	} else {
324 		WRITE_ONCE(scs->output, NULL);
325 	}
326 }
327 static void midi_playback_drain(struct snd_rawmidi_substream *stream)
328 {
329 	struct fw_scs1x *scs = stream->rmidi->private_data;
330 
331 	wait_event(scs->idle_wait, scs->output_idle);
332 }
333 
334 static int register_address(struct snd_oxfw *oxfw)
335 {
336 	struct fw_scs1x *scs = oxfw->spec;
337 	__be64 data;
338 
339 	data = cpu_to_be64(((u64)HSS1394_TAG_CHANGE_ADDRESS << 56) |
340 			    scs->hss_handler.offset);
341 	return snd_fw_transaction(oxfw->unit, TCODE_WRITE_BLOCK_REQUEST,
342 				  HSS1394_ADDRESS, &data, sizeof(data), 0);
343 }
344 
345 static void remove_scs1x(struct snd_rawmidi *rmidi)
346 {
347 	struct fw_scs1x *scs = rmidi->private_data;
348 
349 	fw_core_remove_address_handler(&scs->hss_handler);
350 }
351 
352 void snd_oxfw_scs1x_update(struct snd_oxfw *oxfw)
353 {
354 	register_address(oxfw);
355 }
356 
357 int snd_oxfw_scs1x_add(struct snd_oxfw *oxfw)
358 {
359 	static const struct snd_rawmidi_ops midi_capture_ops = {
360 		.open    = midi_capture_open,
361 		.close   = midi_capture_close,
362 		.trigger = midi_capture_trigger,
363 	};
364 	static const struct snd_rawmidi_ops midi_playback_ops = {
365 		.open    = midi_playback_open,
366 		.close   = midi_playback_close,
367 		.trigger = midi_playback_trigger,
368 		.drain   = midi_playback_drain,
369 	};
370 	struct snd_rawmidi *rmidi;
371 	struct fw_scs1x *scs;
372 	int err;
373 
374 	scs = devm_kzalloc(&oxfw->card->card_dev, sizeof(struct fw_scs1x),
375 			   GFP_KERNEL);
376 	if (!scs)
377 		return -ENOMEM;
378 	scs->fw_dev = fw_parent_device(oxfw->unit);
379 	oxfw->spec = scs;
380 
381 	/* Allocate own handler for imcoming asynchronous transaction. */
382 	scs->hss_handler.length = HSS1394_MAX_PACKET_SIZE;
383 	scs->hss_handler.address_callback = handle_hss;
384 	scs->hss_handler.callback_data = scs;
385 	err = fw_core_add_address_handler(&scs->hss_handler,
386 					  &fw_high_memory_region);
387 	if (err < 0)
388 		return err;
389 
390 	err = register_address(oxfw);
391 	if (err < 0)
392 		goto err_allocated;
393 
394 	/* Use unique name for backward compatibility to scs1x module. */
395 	err = snd_rawmidi_new(oxfw->card, "SCS.1x", 0, 1, 1, &rmidi);
396 	if (err < 0)
397 		goto err_allocated;
398 	rmidi->private_data = scs;
399 	rmidi->private_free = remove_scs1x;
400 
401 	snprintf(rmidi->name, sizeof(rmidi->name),
402 		 "%s MIDI", oxfw->card->shortname);
403 
404 	rmidi->info_flags = SNDRV_RAWMIDI_INFO_INPUT |
405 			    SNDRV_RAWMIDI_INFO_OUTPUT |
406 			    SNDRV_RAWMIDI_INFO_DUPLEX;
407 	snd_rawmidi_set_ops(rmidi, SNDRV_RAWMIDI_STREAM_INPUT,
408 			    &midi_capture_ops);
409 	snd_rawmidi_set_ops(rmidi, SNDRV_RAWMIDI_STREAM_OUTPUT,
410 			    &midi_playback_ops);
411 
412 	INIT_WORK(&scs->work, scs_output_work);
413 	init_waitqueue_head(&scs->idle_wait);
414 	scs->output_idle = true;
415 
416 	return 0;
417 err_allocated:
418 	fw_core_remove_address_handler(&scs->hss_handler);
419 	return err;
420 }
421