1 /*
2  * tascam-transaction.c - a part of driver for TASCAM FireWire series
3  *
4  * Copyright (c) 2015 Takashi Sakamoto
5  *
6  * Licensed under the terms of the GNU General Public License, version 2.
7  */
8 
9 #include "tascam.h"
10 
11 /*
12  * When return minus value, given argument is not MIDI status.
13  * When return 0, given argument is a beginning of system exclusive.
14  * When return the others, given argument is MIDI data.
15  */
16 static inline int calculate_message_bytes(u8 status)
17 {
18 	switch (status) {
19 	case 0xf6:	/* Tune request. */
20 	case 0xf8:	/* Timing clock. */
21 	case 0xfa:	/* Start. */
22 	case 0xfb:	/* Continue. */
23 	case 0xfc:	/* Stop. */
24 	case 0xfe:	/* Active sensing. */
25 	case 0xff:	/* System reset. */
26 		return 1;
27 	case 0xf1:	/* MIDI time code quarter frame. */
28 	case 0xf3:	/* Song select. */
29 		return 2;
30 	case 0xf2:	/* Song position pointer. */
31 		return 3;
32 	case 0xf0:	/* Exclusive. */
33 		return 0;
34 	case 0xf7:	/* End of exclusive. */
35 		break;
36 	case 0xf4:	/* Undefined. */
37 	case 0xf5:	/* Undefined. */
38 	case 0xf9:	/* Undefined. */
39 	case 0xfd:	/* Undefined. */
40 		break;
41 	default:
42 		switch (status & 0xf0) {
43 		case 0x80:	/* Note on. */
44 		case 0x90:	/* Note off. */
45 		case 0xa0:	/* Polyphonic key pressure. */
46 		case 0xb0:	/* Control change and Mode change. */
47 		case 0xe0:	/* Pitch bend change. */
48 			return 3;
49 		case 0xc0:	/* Program change. */
50 		case 0xd0:	/* Channel pressure. */
51 			return 2;
52 		default:
53 		break;
54 		}
55 	break;
56 	}
57 
58 	return -EINVAL;
59 }
60 
61 static int fill_message(struct snd_rawmidi_substream *substream, u8 *buf)
62 {
63 	struct snd_tscm *tscm = substream->rmidi->private_data;
64 	unsigned int port = substream->number;
65 	int i, len, consume;
66 	u8 *label, *msg;
67 	u8 status;
68 
69 	/* The first byte is used for label, the rest for MIDI bytes. */
70 	label = buf;
71 	msg = buf + 1;
72 
73 	consume = snd_rawmidi_transmit_peek(substream, msg, 3);
74 	if (consume == 0)
75 		return 0;
76 
77 	/* On exclusive message. */
78 	if (tscm->on_sysex[port]) {
79 		/* Seek the end of exclusives. */
80 		for (i = 0; i < consume; ++i) {
81 			if (msg[i] == 0xf7) {
82 				tscm->on_sysex[port] = false;
83 				break;
84 			}
85 		}
86 
87 		/* At the end of exclusive message, use label 0x07. */
88 		if (!tscm->on_sysex[port]) {
89 			consume = i + 1;
90 			*label = (port << 4) | 0x07;
91 		/* During exclusive message, use label 0x04. */
92 		} else if (consume == 3) {
93 			*label = (port << 4) | 0x04;
94 		/* We need to fill whole 3 bytes. Go to next change. */
95 		} else {
96 			return 0;
97 		}
98 
99 		len = consume;
100 	} else {
101 		/* The beginning of exclusives. */
102 		if (msg[0] == 0xf0) {
103 			/* Transfer it in next chance in another condition. */
104 			tscm->on_sysex[port] = true;
105 			return 0;
106 		} else {
107 			/* On running-status. */
108 			if ((msg[0] & 0x80) != 0x80)
109 				status = tscm->running_status[port];
110 			else
111 				status = msg[0];
112 
113 			/* Calculate consume bytes. */
114 			len = calculate_message_bytes(status);
115 			if (len <= 0)
116 				return 0;
117 
118 			/* On running-status. */
119 			if ((msg[0] & 0x80) != 0x80) {
120 				/* Enough MIDI bytes were not retrieved. */
121 				if (consume < len - 1)
122 					return 0;
123 				consume = len - 1;
124 
125 				msg[2] = msg[1];
126 				msg[1] = msg[0];
127 				msg[0] = tscm->running_status[port];
128 			} else {
129 				/* Enough MIDI bytes were not retrieved. */
130 				if (consume < len)
131 					return 0;
132 				consume = len;
133 
134 				tscm->running_status[port] = msg[0];
135 			}
136 		}
137 
138 		*label = (port << 4) | (msg[0] >> 4);
139 	}
140 
141 	if (len > 0 && len < 3)
142 		memset(msg + len, 0, 3 - len);
143 
144 	return consume;
145 }
146 
147 static void handle_midi_tx(struct fw_card *card, struct fw_request *request,
148 			   int tcode, int destination, int source,
149 			   int generation, unsigned long long offset,
150 			   void *data, size_t length, void *callback_data)
151 {
152 	struct snd_tscm *tscm = callback_data;
153 	u32 *buf = (u32 *)data;
154 	unsigned int messages;
155 	unsigned int i;
156 	unsigned int port;
157 	struct snd_rawmidi_substream *substream;
158 	u8 *b;
159 	int bytes;
160 
161 	if (offset != tscm->async_handler.offset)
162 		goto end;
163 
164 	messages = length / 8;
165 	for (i = 0; i < messages; i++) {
166 		b = (u8 *)(buf + i * 2);
167 
168 		port = b[0] >> 4;
169 		/* TODO: support virtual MIDI ports. */
170 		if (port >= tscm->spec->midi_capture_ports)
171 			goto end;
172 
173 		/* Assume the message length. */
174 		bytes = calculate_message_bytes(b[1]);
175 		/* On MIDI data or exclusives. */
176 		if (bytes <= 0) {
177 			/* Seek the end of exclusives. */
178 			for (bytes = 1; bytes < 4; bytes++) {
179 				if (b[bytes] == 0xf7)
180 					break;
181 			}
182 			if (bytes == 4)
183 				bytes = 3;
184 		}
185 
186 		substream = ACCESS_ONCE(tscm->tx_midi_substreams[port]);
187 		if (substream != NULL)
188 			snd_rawmidi_receive(substream, b + 1, bytes);
189 	}
190 end:
191 	fw_send_response(card, request, RCODE_COMPLETE);
192 }
193 
194 int snd_tscm_transaction_register(struct snd_tscm *tscm)
195 {
196 	static const struct fw_address_region resp_register_region = {
197 		.start	= 0xffffe0000000ull,
198 		.end	= 0xffffe000ffffull,
199 	};
200 	unsigned int i;
201 	int err;
202 
203 	/*
204 	 * Usually, two quadlets are transferred by one transaction. The first
205 	 * quadlet has MIDI messages, the rest includes timestamp.
206 	 * Sometimes, 8 set of the data is transferred by a block transaction.
207 	 */
208 	tscm->async_handler.length = 8 * 8;
209 	tscm->async_handler.address_callback = handle_midi_tx;
210 	tscm->async_handler.callback_data = tscm;
211 
212 	err = fw_core_add_address_handler(&tscm->async_handler,
213 					  &resp_register_region);
214 	if (err < 0)
215 		return err;
216 
217 	err = snd_tscm_transaction_reregister(tscm);
218 	if (err < 0)
219 		goto error;
220 
221 	for (i = 0; i < TSCM_MIDI_OUT_PORT_MAX; i++) {
222 		err = snd_fw_async_midi_port_init(
223 				&tscm->out_ports[i], tscm->unit,
224 				TSCM_ADDR_BASE + TSCM_OFFSET_MIDI_RX_QUAD,
225 				4, fill_message);
226 		if (err < 0)
227 			goto error;
228 	}
229 
230 	return err;
231 error:
232 	fw_core_remove_address_handler(&tscm->async_handler);
233 	tscm->async_handler.callback_data = NULL;
234 	return err;
235 }
236 
237 /* At bus reset, these registers are cleared. */
238 int snd_tscm_transaction_reregister(struct snd_tscm *tscm)
239 {
240 	struct fw_device *device = fw_parent_device(tscm->unit);
241 	__be32 reg;
242 	int err;
243 
244 	/* Register messaging address. Block transaction is not allowed. */
245 	reg = cpu_to_be32((device->card->node_id << 16) |
246 			  (tscm->async_handler.offset >> 32));
247 	err = snd_fw_transaction(tscm->unit, TCODE_WRITE_QUADLET_REQUEST,
248 				 TSCM_ADDR_BASE + TSCM_OFFSET_MIDI_TX_ADDR_HI,
249 				 &reg, sizeof(reg), 0);
250 	if (err < 0)
251 		return err;
252 
253 	reg = cpu_to_be32(tscm->async_handler.offset);
254 	err = snd_fw_transaction(tscm->unit, TCODE_WRITE_QUADLET_REQUEST,
255 				 TSCM_ADDR_BASE + TSCM_OFFSET_MIDI_TX_ADDR_LO,
256 				 &reg, sizeof(reg), 0);
257 	if (err < 0)
258 		return err;
259 
260 	/* Turn on messaging. */
261 	reg = cpu_to_be32(0x00000001);
262 	err = snd_fw_transaction(tscm->unit, TCODE_WRITE_QUADLET_REQUEST,
263 				  TSCM_ADDR_BASE + TSCM_OFFSET_MIDI_TX_ON,
264 				  &reg, sizeof(reg), 0);
265 	if (err < 0)
266 		return err;
267 
268 	/* Turn on FireWire LED. */
269 	reg = cpu_to_be32(0x0001008e);
270 	return snd_fw_transaction(tscm->unit, TCODE_WRITE_QUADLET_REQUEST,
271 				  TSCM_ADDR_BASE + TSCM_OFFSET_LED_POWER,
272 				  &reg, sizeof(reg), 0);
273 }
274 
275 void snd_tscm_transaction_unregister(struct snd_tscm *tscm)
276 {
277 	__be32 reg;
278 	unsigned int i;
279 
280 	if (tscm->async_handler.callback_data == NULL)
281 		return;
282 
283 	/* Turn off FireWire LED. */
284 	reg = cpu_to_be32(0x0000008e);
285 	snd_fw_transaction(tscm->unit, TCODE_WRITE_QUADLET_REQUEST,
286 			   TSCM_ADDR_BASE + TSCM_OFFSET_LED_POWER,
287 			   &reg, sizeof(reg), 0);
288 
289 	/* Turn off messaging. */
290 	reg = cpu_to_be32(0x00000000);
291 	snd_fw_transaction(tscm->unit, TCODE_WRITE_QUADLET_REQUEST,
292 			   TSCM_ADDR_BASE + TSCM_OFFSET_MIDI_TX_ON,
293 			   &reg, sizeof(reg), 0);
294 
295 	/* Unregister the address. */
296 	snd_fw_transaction(tscm->unit, TCODE_WRITE_QUADLET_REQUEST,
297 			   TSCM_ADDR_BASE + TSCM_OFFSET_MIDI_TX_ADDR_HI,
298 			   &reg, sizeof(reg), 0);
299 	snd_fw_transaction(tscm->unit, TCODE_WRITE_QUADLET_REQUEST,
300 			   TSCM_ADDR_BASE + TSCM_OFFSET_MIDI_TX_ADDR_LO,
301 			   &reg, sizeof(reg), 0);
302 
303 	fw_core_remove_address_handler(&tscm->async_handler);
304 	tscm->async_handler.callback_data = NULL;
305 
306 	for (i = 0; i < TSCM_MIDI_OUT_PORT_MAX; i++)
307 		snd_fw_async_midi_port_destroy(&tscm->out_ports[i]);
308 }
309