xref: /openbmc/linux/sound/firewire/oxfw/oxfw-scs1x.c (revision cd4d09ec)
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 tasklet_struct tasklet;
30 	wait_queue_head_t idle_wait;
31 	u8 buffer[HSS1394_MAX_PACKET_SIZE];
32 	bool transaction_running;
33 	struct fw_transaction transaction;
34 	struct fw_device *fw_dev;
35 };
36 
37 static const u8 sysex_escape_prefix[] = {
38 	0xf0,			/* SysEx begin */
39 	0x00, 0x01, 0x60,	/* Stanton DJ */
40 	0x48, 0x53, 0x53,	/* "HSS" */
41 };
42 
43 static void midi_input_escaped_byte(struct snd_rawmidi_substream *stream,
44 				    u8 byte)
45 {
46 	u8 nibbles[2];
47 
48 	nibbles[0] = byte >> 4;
49 	nibbles[1] = byte & 0x0f;
50 	snd_rawmidi_receive(stream, nibbles, 2);
51 }
52 
53 static void midi_input_byte(struct fw_scs1x *scs,
54 			    struct snd_rawmidi_substream *stream, u8 byte)
55 {
56 	const u8 eox = 0xf7;
57 
58 	if (scs->input_escape_count > 0) {
59 		midi_input_escaped_byte(stream, byte);
60 		scs->input_escape_count--;
61 		if (scs->input_escape_count == 0)
62 			snd_rawmidi_receive(stream, &eox, sizeof(eox));
63 	} else if (byte == 0xf9) {
64 		snd_rawmidi_receive(stream, sysex_escape_prefix,
65 				    ARRAY_SIZE(sysex_escape_prefix));
66 		midi_input_escaped_byte(stream, 0x00);
67 		midi_input_escaped_byte(stream, 0xf9);
68 		scs->input_escape_count = 3;
69 	} else {
70 		snd_rawmidi_receive(stream, &byte, 1);
71 	}
72 }
73 
74 static void midi_input_packet(struct fw_scs1x *scs,
75 			      struct snd_rawmidi_substream *stream,
76 			      const u8 *data, unsigned int bytes)
77 {
78 	unsigned int i;
79 	const u8 eox = 0xf7;
80 
81 	if (data[0] == HSS1394_TAG_USER_DATA) {
82 		for (i = 1; i < bytes; ++i)
83 			midi_input_byte(scs, stream, data[i]);
84 	} else {
85 		snd_rawmidi_receive(stream, sysex_escape_prefix,
86 				    ARRAY_SIZE(sysex_escape_prefix));
87 		for (i = 0; i < bytes; ++i)
88 			midi_input_escaped_byte(stream, data[i]);
89 		snd_rawmidi_receive(stream, &eox, sizeof(eox));
90 	}
91 }
92 
93 static void handle_hss(struct fw_card *card, struct fw_request *request,
94 		       int tcode, int destination, int source, int generation,
95 		       unsigned long long offset, void *data, size_t length,
96 		       void *callback_data)
97 {
98 	struct fw_scs1x *scs = callback_data;
99 	struct snd_rawmidi_substream *stream;
100 	int rcode;
101 
102 	if (offset != scs->hss_handler.offset) {
103 		rcode = RCODE_ADDRESS_ERROR;
104 		goto end;
105 	}
106 	if (tcode != TCODE_WRITE_QUADLET_REQUEST &&
107 	    tcode != TCODE_WRITE_BLOCK_REQUEST) {
108 		rcode = RCODE_TYPE_ERROR;
109 		goto end;
110 	}
111 
112 	if (length >= 1) {
113 		stream = ACCESS_ONCE(scs->input);
114 		if (stream)
115 			midi_input_packet(scs, stream, data, length);
116 	}
117 
118 	rcode = RCODE_COMPLETE;
119 end:
120 	fw_send_response(card, request, rcode);
121 }
122 
123 static void scs_write_callback(struct fw_card *card, int rcode,
124 			       void *data, size_t length, void *callback_data)
125 {
126 	struct fw_scs1x *scs = callback_data;
127 
128 	if (rcode == RCODE_GENERATION)
129 		;	/* TODO: retry this packet */
130 
131 	scs->transaction_running = false;
132 	tasklet_schedule(&scs->tasklet);
133 }
134 
135 static bool is_valid_running_status(u8 status)
136 {
137 	return status >= 0x80 && status <= 0xef;
138 }
139 
140 static bool is_one_byte_cmd(u8 status)
141 {
142 	return status == 0xf6 ||
143 	       status >= 0xf8;
144 }
145 
146 static bool is_two_bytes_cmd(u8 status)
147 {
148 	return (status >= 0xc0 && status <= 0xdf) ||
149 	       status == 0xf1 ||
150 	       status == 0xf3;
151 }
152 
153 static bool is_three_bytes_cmd(u8 status)
154 {
155 	return (status >= 0x80 && status <= 0xbf) ||
156 	       (status >= 0xe0 && status <= 0xef) ||
157 	       status == 0xf2;
158 }
159 
160 static bool is_invalid_cmd(u8 status)
161 {
162 	return status == 0xf4 ||
163 	       status == 0xf5 ||
164 	       status == 0xf9 ||
165 	       status == 0xfd;
166 }
167 
168 static void scs_output_tasklet(unsigned long data)
169 {
170 	struct fw_scs1x *scs = (struct fw_scs1x *)data;
171 	struct snd_rawmidi_substream *stream;
172 	unsigned int i;
173 	u8 byte;
174 	int generation;
175 
176 	if (scs->transaction_running)
177 		return;
178 
179 	stream = ACCESS_ONCE(scs->output);
180 	if (!stream) {
181 		scs->output_idle = true;
182 		wake_up(&scs->idle_wait);
183 		return;
184 	}
185 
186 	i = scs->output_bytes;
187 	for (;;) {
188 		if (snd_rawmidi_transmit(stream, &byte, 1) != 1) {
189 			scs->output_bytes = i;
190 			scs->output_idle = true;
191 			wake_up(&scs->idle_wait);
192 			return;
193 		}
194 		/*
195 		 * Convert from real MIDI to what I think the device expects (no
196 		 * running status, one command per packet, unescaped SysExs).
197 		 */
198 		if (scs->output_escaped && byte < 0x80) {
199 			if (scs->output_escape_high_nibble) {
200 				if (i < HSS1394_MAX_PACKET_SIZE) {
201 					scs->buffer[i] = byte << 4;
202 					scs->output_escape_high_nibble = false;
203 				}
204 			} else {
205 				scs->buffer[i++] |= byte & 0x0f;
206 				scs->output_escape_high_nibble = true;
207 			}
208 		} else if (byte < 0x80) {
209 			if (i == 1) {
210 				if (!is_valid_running_status(
211 							scs->output_status))
212 					continue;
213 				scs->buffer[0] = HSS1394_TAG_USER_DATA;
214 				scs->buffer[i++] = scs->output_status;
215 			}
216 			scs->buffer[i++] = byte;
217 			if ((i == 3 && is_two_bytes_cmd(scs->output_status)) ||
218 			    (i == 4 && is_three_bytes_cmd(scs->output_status)))
219 				break;
220 			if (i == 1 + ARRAY_SIZE(sysex_escape_prefix) &&
221 			    !memcmp(scs->buffer + 1, sysex_escape_prefix,
222 				    ARRAY_SIZE(sysex_escape_prefix))) {
223 				scs->output_escaped = true;
224 				scs->output_escape_high_nibble = true;
225 				i = 0;
226 			}
227 			if (i >= HSS1394_MAX_PACKET_SIZE)
228 				i = 1;
229 		} else if (byte == 0xf7) {
230 			if (scs->output_escaped) {
231 				if (i >= 1 && scs->output_escape_high_nibble &&
232 				    scs->buffer[0] !=
233 						HSS1394_TAG_CHANGE_ADDRESS)
234 					break;
235 			} else {
236 				if (i > 1 && scs->output_status == 0xf0) {
237 					scs->buffer[i++] = 0xf7;
238 					break;
239 				}
240 			}
241 			i = 1;
242 			scs->output_escaped = false;
243 		} else if (!is_invalid_cmd(byte) && byte < 0xf8) {
244 			i = 1;
245 			scs->buffer[0] = HSS1394_TAG_USER_DATA;
246 			scs->buffer[i++] = byte;
247 			scs->output_status = byte;
248 			scs->output_escaped = false;
249 			if (is_one_byte_cmd(byte))
250 				break;
251 		}
252 	}
253 	scs->output_bytes = 1;
254 	scs->output_escaped = false;
255 
256 	scs->transaction_running = true;
257 	generation = scs->fw_dev->generation;
258 	smp_rmb(); /* node_id vs. generation */
259 	fw_send_request(scs->fw_dev->card, &scs->transaction,
260 			TCODE_WRITE_BLOCK_REQUEST, scs->fw_dev->node_id,
261 			generation, scs->fw_dev->max_speed, HSS1394_ADDRESS,
262 			scs->buffer, i, scs_write_callback, scs);
263 }
264 
265 static int midi_capture_open(struct snd_rawmidi_substream *stream)
266 {
267 	return 0;
268 }
269 
270 static int midi_capture_close(struct snd_rawmidi_substream *stream)
271 {
272 	return 0;
273 }
274 
275 static void midi_capture_trigger(struct snd_rawmidi_substream *stream, int up)
276 {
277 	struct fw_scs1x *scs = stream->rmidi->private_data;
278 
279 	if (up) {
280 		scs->input_escape_count = 0;
281 		ACCESS_ONCE(scs->input) = stream;
282 	} else {
283 		ACCESS_ONCE(scs->input) = NULL;
284 	}
285 }
286 
287 static struct snd_rawmidi_ops midi_capture_ops = {
288 	.open    = midi_capture_open,
289 	.close   = midi_capture_close,
290 	.trigger = midi_capture_trigger,
291 };
292 
293 static int midi_playback_open(struct snd_rawmidi_substream *stream)
294 {
295 	return 0;
296 }
297 
298 static int midi_playback_close(struct snd_rawmidi_substream *stream)
299 {
300 	return 0;
301 }
302 
303 static void midi_playback_trigger(struct snd_rawmidi_substream *stream, int up)
304 {
305 	struct fw_scs1x *scs = stream->rmidi->private_data;
306 
307 	if (up) {
308 		scs->output_status = 0;
309 		scs->output_bytes = 1;
310 		scs->output_escaped = false;
311 		scs->output_idle = false;
312 
313 		ACCESS_ONCE(scs->output) = stream;
314 		tasklet_schedule(&scs->tasklet);
315 	} else {
316 		ACCESS_ONCE(scs->output) = NULL;
317 	}
318 }
319 static void midi_playback_drain(struct snd_rawmidi_substream *stream)
320 {
321 	struct fw_scs1x *scs = stream->rmidi->private_data;
322 
323 	wait_event(scs->idle_wait, scs->output_idle);
324 }
325 
326 static struct snd_rawmidi_ops midi_playback_ops = {
327 	.open    = midi_playback_open,
328 	.close   = midi_playback_close,
329 	.trigger = midi_playback_trigger,
330 	.drain   = midi_playback_drain,
331 };
332 static int register_address(struct snd_oxfw *oxfw)
333 {
334 	struct fw_scs1x *scs = oxfw->spec;
335 	__be64 data;
336 
337 	data = cpu_to_be64(((u64)HSS1394_TAG_CHANGE_ADDRESS << 56) |
338 			    scs->hss_handler.offset);
339 	return snd_fw_transaction(oxfw->unit, TCODE_WRITE_BLOCK_REQUEST,
340 				  HSS1394_ADDRESS, &data, sizeof(data), 0);
341 }
342 
343 static void remove_scs1x(struct snd_rawmidi *rmidi)
344 {
345 	struct fw_scs1x *scs = rmidi->private_data;
346 
347 	fw_core_remove_address_handler(&scs->hss_handler);
348 }
349 
350 void snd_oxfw_scs1x_update(struct snd_oxfw *oxfw)
351 {
352 	register_address(oxfw);
353 }
354 
355 int snd_oxfw_scs1x_add(struct snd_oxfw *oxfw)
356 {
357 	struct snd_rawmidi *rmidi;
358 	struct fw_scs1x *scs;
359 	int err;
360 
361 	scs = kzalloc(sizeof(struct fw_scs1x), GFP_KERNEL);
362 	if (scs == NULL)
363 		return -ENOMEM;
364 	scs->fw_dev = fw_parent_device(oxfw->unit);
365 	oxfw->spec = scs;
366 
367 	/* Allocate own handler for imcoming asynchronous transaction. */
368 	scs->hss_handler.length = HSS1394_MAX_PACKET_SIZE;
369 	scs->hss_handler.address_callback = handle_hss;
370 	scs->hss_handler.callback_data = scs;
371 	err = fw_core_add_address_handler(&scs->hss_handler,
372 					  &fw_high_memory_region);
373 	if (err < 0)
374 		return err;
375 
376 	err = register_address(oxfw);
377 	if (err < 0)
378 		goto err_allocated;
379 
380 	/* Use unique name for backward compatibility to scs1x module. */
381 	err = snd_rawmidi_new(oxfw->card, "SCS.1x", 0, 1, 1, &rmidi);
382 	if (err < 0)
383 		goto err_allocated;
384 	rmidi->private_data = scs;
385 	rmidi->private_free = remove_scs1x;
386 
387 	snprintf(rmidi->name, sizeof(rmidi->name),
388 		 "%s MIDI", oxfw->card->shortname);
389 
390 	rmidi->info_flags = SNDRV_RAWMIDI_INFO_INPUT |
391 			    SNDRV_RAWMIDI_INFO_OUTPUT |
392 			    SNDRV_RAWMIDI_INFO_DUPLEX;
393 	snd_rawmidi_set_ops(rmidi, SNDRV_RAWMIDI_STREAM_INPUT,
394 			    &midi_capture_ops);
395 	snd_rawmidi_set_ops(rmidi, SNDRV_RAWMIDI_STREAM_OUTPUT,
396 			    &midi_playback_ops);
397 
398 	tasklet_init(&scs->tasklet, scs_output_tasklet, (unsigned long)scs);
399 	init_waitqueue_head(&scs->idle_wait);
400 	scs->output_idle = true;
401 
402 	return 0;
403 err_allocated:
404 	fw_core_remove_address_handler(&scs->hss_handler);
405 	return err;
406 }
407