xref: /openbmc/linux/sound/firewire/oxfw/oxfw-scs1x.c (revision d3964221)
1 /*
2  * oxfw-scs1x.c - a part of driver for OXFW970/971 based devices
3  *
4  * Copyright (c) Clemens Ladisch <clemens@ladisch.de>
5  * Copyright (c) 2015 Takashi Sakamoto <o-takashi@sakamocchi.jp>
6  *
7  * Licensed under the terms of the GNU General Public License, version 2.
8  */
9 
10 #include "oxfw.h"
11 
12 #define HSS1394_ADDRESS			0xc007dedadadaULL
13 #define HSS1394_MAX_PACKET_SIZE		64
14 #define HSS1394_TAG_USER_DATA		0x00
15 #define HSS1394_TAG_CHANGE_ADDRESS	0xf1
16 
17 struct fw_scs1x {
18 	struct fw_address_handler hss_handler;
19 	u8 input_escape_count;
20 	struct snd_rawmidi_substream *input;
21 
22 	/* For MIDI playback. */
23 	struct snd_rawmidi_substream *output;
24 	bool output_idle;
25 	u8 output_status;
26 	u8 output_bytes;
27 	bool output_escaped;
28 	bool output_escape_high_nibble;
29 	struct work_struct work;
30 	wait_queue_head_t idle_wait;
31 	u8 buffer[HSS1394_MAX_PACKET_SIZE];
32 	bool transaction_running;
33 	struct fw_transaction transaction;
34 	unsigned int transaction_bytes;
35 	bool error;
36 	struct fw_device *fw_dev;
37 };
38 
39 static const u8 sysex_escape_prefix[] = {
40 	0xf0,			/* SysEx begin */
41 	0x00, 0x01, 0x60,	/* Stanton DJ */
42 	0x48, 0x53, 0x53,	/* "HSS" */
43 };
44 
45 static void midi_input_escaped_byte(struct snd_rawmidi_substream *stream,
46 				    u8 byte)
47 {
48 	u8 nibbles[2];
49 
50 	nibbles[0] = byte >> 4;
51 	nibbles[1] = byte & 0x0f;
52 	snd_rawmidi_receive(stream, nibbles, 2);
53 }
54 
55 static void midi_input_byte(struct fw_scs1x *scs,
56 			    struct snd_rawmidi_substream *stream, u8 byte)
57 {
58 	const u8 eox = 0xf7;
59 
60 	if (scs->input_escape_count > 0) {
61 		midi_input_escaped_byte(stream, byte);
62 		scs->input_escape_count--;
63 		if (scs->input_escape_count == 0)
64 			snd_rawmidi_receive(stream, &eox, sizeof(eox));
65 	} else if (byte == 0xf9) {
66 		snd_rawmidi_receive(stream, sysex_escape_prefix,
67 				    ARRAY_SIZE(sysex_escape_prefix));
68 		midi_input_escaped_byte(stream, 0x00);
69 		midi_input_escaped_byte(stream, 0xf9);
70 		scs->input_escape_count = 3;
71 	} else {
72 		snd_rawmidi_receive(stream, &byte, 1);
73 	}
74 }
75 
76 static void midi_input_packet(struct fw_scs1x *scs,
77 			      struct snd_rawmidi_substream *stream,
78 			      const u8 *data, unsigned int bytes)
79 {
80 	unsigned int i;
81 	const u8 eox = 0xf7;
82 
83 	if (data[0] == HSS1394_TAG_USER_DATA) {
84 		for (i = 1; i < bytes; ++i)
85 			midi_input_byte(scs, stream, data[i]);
86 	} else {
87 		snd_rawmidi_receive(stream, sysex_escape_prefix,
88 				    ARRAY_SIZE(sysex_escape_prefix));
89 		for (i = 0; i < bytes; ++i)
90 			midi_input_escaped_byte(stream, data[i]);
91 		snd_rawmidi_receive(stream, &eox, sizeof(eox));
92 	}
93 }
94 
95 static void handle_hss(struct fw_card *card, struct fw_request *request,
96 		       int tcode, int destination, int source, int generation,
97 		       unsigned long long offset, void *data, size_t length,
98 		       void *callback_data)
99 {
100 	struct fw_scs1x *scs = callback_data;
101 	struct snd_rawmidi_substream *stream;
102 	int rcode;
103 
104 	if (offset != scs->hss_handler.offset) {
105 		rcode = RCODE_ADDRESS_ERROR;
106 		goto end;
107 	}
108 	if (tcode != TCODE_WRITE_QUADLET_REQUEST &&
109 	    tcode != TCODE_WRITE_BLOCK_REQUEST) {
110 		rcode = RCODE_TYPE_ERROR;
111 		goto end;
112 	}
113 
114 	if (length >= 1) {
115 		stream = READ_ONCE(scs->input);
116 		if (stream)
117 			midi_input_packet(scs, stream, data, length);
118 	}
119 
120 	rcode = RCODE_COMPLETE;
121 end:
122 	fw_send_response(card, request, rcode);
123 }
124 
125 static void scs_write_callback(struct fw_card *card, int rcode,
126 			       void *data, size_t length, void *callback_data)
127 {
128 	struct fw_scs1x *scs = callback_data;
129 
130 	if (!rcode_is_permanent_error(rcode)) {
131 		/* Don't retry for this data. */
132 		if (rcode == RCODE_COMPLETE)
133 			scs->transaction_bytes = 0;
134 	} else {
135 		scs->error = true;
136 	}
137 
138 	scs->transaction_running = false;
139 	schedule_work(&scs->work);
140 }
141 
142 static bool is_valid_running_status(u8 status)
143 {
144 	return status >= 0x80 && status <= 0xef;
145 }
146 
147 static bool is_one_byte_cmd(u8 status)
148 {
149 	return status == 0xf6 ||
150 	       status >= 0xf8;
151 }
152 
153 static bool is_two_bytes_cmd(u8 status)
154 {
155 	return (status >= 0xc0 && status <= 0xdf) ||
156 	       status == 0xf1 ||
157 	       status == 0xf3;
158 }
159 
160 static bool is_three_bytes_cmd(u8 status)
161 {
162 	return (status >= 0x80 && status <= 0xbf) ||
163 	       (status >= 0xe0 && status <= 0xef) ||
164 	       status == 0xf2;
165 }
166 
167 static bool is_invalid_cmd(u8 status)
168 {
169 	return status == 0xf4 ||
170 	       status == 0xf5 ||
171 	       status == 0xf9 ||
172 	       status == 0xfd;
173 }
174 
175 static void scs_output_work(struct work_struct *work)
176 {
177 	struct fw_scs1x *scs = container_of(work, struct fw_scs1x, work);
178 	struct snd_rawmidi_substream *stream;
179 	unsigned int i;
180 	u8 byte;
181 	int generation;
182 
183 	if (scs->transaction_running)
184 		return;
185 
186 	stream = READ_ONCE(scs->output);
187 	if (!stream || scs->error) {
188 		scs->output_idle = true;
189 		wake_up(&scs->idle_wait);
190 		return;
191 	}
192 
193 	if (scs->transaction_bytes > 0)
194 		goto retry;
195 
196 	i = scs->output_bytes;
197 	for (;;) {
198 		if (snd_rawmidi_transmit(stream, &byte, 1) != 1) {
199 			scs->output_bytes = i;
200 			scs->output_idle = true;
201 			wake_up(&scs->idle_wait);
202 			return;
203 		}
204 		/*
205 		 * Convert from real MIDI to what I think the device expects (no
206 		 * running status, one command per packet, unescaped SysExs).
207 		 */
208 		if (scs->output_escaped && byte < 0x80) {
209 			if (scs->output_escape_high_nibble) {
210 				if (i < HSS1394_MAX_PACKET_SIZE) {
211 					scs->buffer[i] = byte << 4;
212 					scs->output_escape_high_nibble = false;
213 				}
214 			} else {
215 				scs->buffer[i++] |= byte & 0x0f;
216 				scs->output_escape_high_nibble = true;
217 			}
218 		} else if (byte < 0x80) {
219 			if (i == 1) {
220 				if (!is_valid_running_status(
221 							scs->output_status))
222 					continue;
223 				scs->buffer[0] = HSS1394_TAG_USER_DATA;
224 				scs->buffer[i++] = scs->output_status;
225 			}
226 			scs->buffer[i++] = byte;
227 			if ((i == 3 && is_two_bytes_cmd(scs->output_status)) ||
228 			    (i == 4 && is_three_bytes_cmd(scs->output_status)))
229 				break;
230 			if (i == 1 + ARRAY_SIZE(sysex_escape_prefix) &&
231 			    !memcmp(scs->buffer + 1, sysex_escape_prefix,
232 				    ARRAY_SIZE(sysex_escape_prefix))) {
233 				scs->output_escaped = true;
234 				scs->output_escape_high_nibble = true;
235 				i = 0;
236 			}
237 			if (i >= HSS1394_MAX_PACKET_SIZE)
238 				i = 1;
239 		} else if (byte == 0xf7) {
240 			if (scs->output_escaped) {
241 				if (i >= 1 && scs->output_escape_high_nibble &&
242 				    scs->buffer[0] !=
243 						HSS1394_TAG_CHANGE_ADDRESS)
244 					break;
245 			} else {
246 				if (i > 1 && scs->output_status == 0xf0) {
247 					scs->buffer[i++] = 0xf7;
248 					break;
249 				}
250 			}
251 			i = 1;
252 			scs->output_escaped = false;
253 		} else if (!is_invalid_cmd(byte) && byte < 0xf8) {
254 			i = 1;
255 			scs->buffer[0] = HSS1394_TAG_USER_DATA;
256 			scs->buffer[i++] = byte;
257 			scs->output_status = byte;
258 			scs->output_escaped = false;
259 			if (is_one_byte_cmd(byte))
260 				break;
261 		}
262 	}
263 	scs->output_bytes = 1;
264 	scs->output_escaped = false;
265 
266 	scs->transaction_bytes = i;
267 retry:
268 	scs->transaction_running = true;
269 	generation = scs->fw_dev->generation;
270 	smp_rmb(); /* node_id vs. generation */
271 	fw_send_request(scs->fw_dev->card, &scs->transaction,
272 			TCODE_WRITE_BLOCK_REQUEST, scs->fw_dev->node_id,
273 			generation, scs->fw_dev->max_speed, HSS1394_ADDRESS,
274 			scs->buffer, scs->transaction_bytes,
275 			scs_write_callback, scs);
276 }
277 
278 static int midi_capture_open(struct snd_rawmidi_substream *stream)
279 {
280 	return 0;
281 }
282 
283 static int midi_capture_close(struct snd_rawmidi_substream *stream)
284 {
285 	return 0;
286 }
287 
288 static void midi_capture_trigger(struct snd_rawmidi_substream *stream, int up)
289 {
290 	struct fw_scs1x *scs = stream->rmidi->private_data;
291 
292 	if (up) {
293 		scs->input_escape_count = 0;
294 		WRITE_ONCE(scs->input, stream);
295 	} else {
296 		WRITE_ONCE(scs->input, NULL);
297 	}
298 }
299 
300 static int midi_playback_open(struct snd_rawmidi_substream *stream)
301 {
302 	return 0;
303 }
304 
305 static int midi_playback_close(struct snd_rawmidi_substream *stream)
306 {
307 	return 0;
308 }
309 
310 static void midi_playback_trigger(struct snd_rawmidi_substream *stream, int up)
311 {
312 	struct fw_scs1x *scs = stream->rmidi->private_data;
313 
314 	if (up) {
315 		scs->output_status = 0;
316 		scs->output_bytes = 1;
317 		scs->output_escaped = false;
318 		scs->output_idle = false;
319 		scs->transaction_bytes = 0;
320 		scs->error = false;
321 
322 		WRITE_ONCE(scs->output, stream);
323 		schedule_work(&scs->work);
324 	} else {
325 		WRITE_ONCE(scs->output, NULL);
326 	}
327 }
328 static void midi_playback_drain(struct snd_rawmidi_substream *stream)
329 {
330 	struct fw_scs1x *scs = stream->rmidi->private_data;
331 
332 	wait_event(scs->idle_wait, scs->output_idle);
333 }
334 
335 static int register_address(struct snd_oxfw *oxfw)
336 {
337 	struct fw_scs1x *scs = oxfw->spec;
338 	__be64 data;
339 
340 	data = cpu_to_be64(((u64)HSS1394_TAG_CHANGE_ADDRESS << 56) |
341 			    scs->hss_handler.offset);
342 	return snd_fw_transaction(oxfw->unit, TCODE_WRITE_BLOCK_REQUEST,
343 				  HSS1394_ADDRESS, &data, sizeof(data), 0);
344 }
345 
346 static void remove_scs1x(struct snd_rawmidi *rmidi)
347 {
348 	struct fw_scs1x *scs = rmidi->private_data;
349 
350 	fw_core_remove_address_handler(&scs->hss_handler);
351 }
352 
353 void snd_oxfw_scs1x_update(struct snd_oxfw *oxfw)
354 {
355 	register_address(oxfw);
356 }
357 
358 int snd_oxfw_scs1x_add(struct snd_oxfw *oxfw)
359 {
360 	static const struct snd_rawmidi_ops midi_capture_ops = {
361 		.open    = midi_capture_open,
362 		.close   = midi_capture_close,
363 		.trigger = midi_capture_trigger,
364 	};
365 	static const struct snd_rawmidi_ops midi_playback_ops = {
366 		.open    = midi_playback_open,
367 		.close   = midi_playback_close,
368 		.trigger = midi_playback_trigger,
369 		.drain   = midi_playback_drain,
370 	};
371 	struct snd_rawmidi *rmidi;
372 	struct fw_scs1x *scs;
373 	int err;
374 
375 	scs = kzalloc(sizeof(struct fw_scs1x), GFP_KERNEL);
376 	if (scs == NULL)
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