summaryrefslogtreecommitdiffstats
path: root/sound/firewire/fireface/ff-transaction.c
blob: dd6c8e839647f64d8eddc203b199e30014bc2738 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
/*
 * ff-transaction.c - a part of driver for RME Fireface series
 *
 * Copyright (c) 2015-2017 Takashi Sakamoto
 *
 * Licensed under the terms of the GNU General Public License, version 2.
 */

#include "ff.h"

static void finish_transmit_midi_msg(struct snd_ff *ff, unsigned int port,
				     int rcode)
{
	struct snd_rawmidi_substream *substream =
				ACCESS_ONCE(ff->rx_midi_substreams[port]);

	if (rcode_is_permanent_error(rcode)) {
		ff->rx_midi_error[port] = true;
		return;
	}

	if (rcode != RCODE_COMPLETE) {
		/* Transfer the message again, immediately. */
		ff->next_ktime[port] = 0;
		schedule_work(&ff->rx_midi_work[port]);
		return;
	}

	snd_rawmidi_transmit_ack(substream, ff->rx_bytes[port]);
	ff->rx_bytes[port] = 0;

	if (!snd_rawmidi_transmit_empty(substream))
		schedule_work(&ff->rx_midi_work[port]);
}

static void finish_transmit_midi0_msg(struct fw_card *card, int rcode,
				      void *data, size_t length,
				      void *callback_data)
{
	struct snd_ff *ff =
		container_of(callback_data, struct snd_ff, transactions[0]);
	finish_transmit_midi_msg(ff, 0, rcode);
}

static void finish_transmit_midi1_msg(struct fw_card *card, int rcode,
				      void *data, size_t length,
				      void *callback_data)
{
	struct snd_ff *ff =
		container_of(callback_data, struct snd_ff, transactions[1]);
	finish_transmit_midi_msg(ff, 1, rcode);
}

static inline void fill_midi_buf(struct snd_ff *ff, unsigned int port,
				 unsigned int index, u8 byte)
{
	ff->msg_buf[port][index] = cpu_to_le32(byte);
}

static void transmit_midi_msg(struct snd_ff *ff, unsigned int port)
{
	struct snd_rawmidi_substream *substream =
			ACCESS_ONCE(ff->rx_midi_substreams[port]);
	u8 *buf = (u8 *)ff->msg_buf[port];
	int i, len;

	struct fw_device *fw_dev = fw_parent_device(ff->unit);
	unsigned long long addr;
	int generation;
	fw_transaction_callback_t callback;

	if (substream == NULL || snd_rawmidi_transmit_empty(substream))
		return;

	if (ff->rx_bytes[port] > 0 || ff->rx_midi_error[port])
		return;

	/* Do it in next chance. */
	if (ktime_after(ff->next_ktime[port], ktime_get())) {
		schedule_work(&ff->rx_midi_work[port]);
		return;
	}

	len = snd_rawmidi_transmit_peek(substream, buf,
					SND_FF_MAXIMIM_MIDI_QUADS);
	if (len <= 0)
		return;

	for (i = len - 1; i >= 0; i--)
		fill_midi_buf(ff, port, i, buf[i]);

	if (port == 0) {
		addr = ff->spec->protocol->midi_rx_port_0_reg;
		callback = finish_transmit_midi0_msg;
	} else {
		addr = ff->spec->protocol->midi_rx_port_1_reg;
		callback = finish_transmit_midi1_msg;
	}

	/* Set interval to next transaction. */
	ff->next_ktime[port] = ktime_add_ns(ktime_get(),
					    len * 8 * NSEC_PER_SEC / 31250);
	ff->rx_bytes[port] = len;

	/*
	 * In Linux FireWire core, when generation is updated with memory
	 * barrier, node id has already been updated. In this module, After
	 * this smp_rmb(), load/store instructions to memory are completed.
	 * Thus, both of generation and node id are available with recent
	 * values. This is a light-serialization solution to handle bus reset
	 * events on IEEE 1394 bus.
	 */
	generation = fw_dev->generation;
	smp_rmb();
	fw_send_request(fw_dev->card, &ff->transactions[port],
			TCODE_WRITE_BLOCK_REQUEST,
			fw_dev->node_id, generation, fw_dev->max_speed,
			addr, &ff->msg_buf[port], len * 4,
			callback, &ff->transactions[port]);
}

static void transmit_midi0_msg(struct work_struct *work)
{
	struct snd_ff *ff = container_of(work, struct snd_ff, rx_midi_work[0]);

	transmit_midi_msg(ff, 0);
}

static void transmit_midi1_msg(struct work_struct *work)
{
	struct snd_ff *ff = container_of(work, struct snd_ff, rx_midi_work[1]);

	transmit_midi_msg(ff, 1);
}

static void handle_midi_msg(struct fw_card *card, struct fw_request *request,
			    int tcode, int destination, int source,
			    int generation, unsigned long long offset,
			    void *data, size_t length, void *callback_data)
{
	struct snd_ff *ff = callback_data;
	__le32 *buf = data;
	u32 quad;
	u8 byte;
	unsigned int index;
	struct snd_rawmidi_substream *substream;
	int i;

	fw_send_response(card, request, RCODE_COMPLETE);

	for (i = 0; i < length / 4; i++) {
		quad = le32_to_cpu(buf[i]);

		/* Message in first port. */
		/*
		 * This value may represent the index of this unit when the same
		 * units are on the same IEEE 1394 bus. This driver doesn't use
		 * it.
		 */
		index = (quad >> 8) & 0xff;
		if (index > 0) {
			substream = ACCESS_ONCE(ff->tx_midi_substreams[0]);
			if (substream != NULL) {
				byte = quad & 0xff;
				snd_rawmidi_receive(substream, &byte, 1);
			}
		}

		/* Message in second port. */
		index = (quad >> 24) & 0xff;
		if (index > 0) {
			substream = ACCESS_ONCE(ff->tx_midi_substreams[1]);
			if (substream != NULL) {
				byte = (quad >> 16) & 0xff;
				snd_rawmidi_receive(substream, &byte, 1);
			}
		}
	}
}

static int allocate_own_address(struct snd_ff *ff, int i)
{
	struct fw_address_region midi_msg_region;
	int err;

	ff->async_handler.length = SND_FF_MAXIMIM_MIDI_QUADS * 4;
	ff->async_handler.address_callback = handle_midi_msg;
	ff->async_handler.callback_data = ff;

	midi_msg_region.start = 0x000100000000ull * i;
	midi_msg_region.end = midi_msg_region.start + ff->async_handler.length;

	err = fw_core_add_address_handler(&ff->async_handler, &midi_msg_region);
	if (err >= 0) {
		/* Controllers are allowed to register this region. */
		if (ff->async_handler.offset & 0x0000ffffffff) {
			fw_core_remove_address_handler(&ff->async_handler);
			err = -EAGAIN;
		}
	}

	return err;
}

/*
 * The configuration to start asynchronous transactions for MIDI messages is in
 * 0x'0000'8010'051c. This register includes the other options, thus this driver
 * doesn't touch it and leaves the decision to userspace. The userspace MUST add
 * 0x04000000 to write transactions to the register to receive any MIDI
 * messages.
 *
 * Here, I just describe MIDI-related offsets of the register, in little-endian
 * order.
 *
 * Controllers are allowed to register higher 4 bytes of address to receive
 * the transactions. The register is 0x'0000'8010'03f4. On the other hand, the
 * controllers are not allowed to register lower 4 bytes of the address. They
 * are forced to select from 4 options by writing corresponding bits to
 * 0x'0000'8010'051c.
 *
 * The 3rd-6th bits in MSB of this register are used to indicate lower 4 bytes
 * of address to which the device transferrs the transactions.
 *  - 6th: 0x'....'....'0000'0180
 *  - 5th: 0x'....'....'0000'0100
 *  - 4th: 0x'....'....'0000'0080
 *  - 3rd: 0x'....'....'0000'0000
 *
 * This driver configure 0x'....'....'0000'0000 for units to receive MIDI
 * messages. 3rd bit of the register should be configured, however this driver
 * deligates this task to user space applications due to a restriction that
 * this register is write-only and the other bits have own effects.
 *
 * The 1st and 2nd bits in LSB of this register are used to cancel transferring
 * asynchronous transactions. These two bits have the same effect.
 *  - 1st/2nd: cancel transferring
 */
int snd_ff_transaction_reregister(struct snd_ff *ff)
{
	struct fw_card *fw_card = fw_parent_device(ff->unit)->card;
	u32 addr;
	__le32 reg;

	/*
	 * Controllers are allowed to register its node ID and upper 2 byte of
	 * local address to listen asynchronous transactions.
	 */
	addr = (fw_card->node_id << 16) | (ff->async_handler.offset >> 32);
	reg = cpu_to_le32(addr);
	return snd_fw_transaction(ff->unit, TCODE_WRITE_QUADLET_REQUEST,
				  ff->spec->protocol->midi_high_addr_reg,
				  &reg, sizeof(reg), 0);
}

int snd_ff_transaction_register(struct snd_ff *ff)
{
	int i, err;

	/*
	 * Allocate in Memory Space of IEC 13213, but lower 4 byte in LSB should
	 * be zero due to device specification.
	 */
	for (i = 0; i < 0xffff; i++) {
		err = allocate_own_address(ff, i);
		if (err != -EBUSY && err != -EAGAIN)
			break;
	}
	if (err < 0)
		return err;

	err = snd_ff_transaction_reregister(ff);
	if (err < 0)
		return err;

	INIT_WORK(&ff->rx_midi_work[0], transmit_midi0_msg);
	INIT_WORK(&ff->rx_midi_work[1], transmit_midi1_msg);

	return 0;
}

void snd_ff_transaction_unregister(struct snd_ff *ff)
{
	__le32 reg;

	if (ff->async_handler.callback_data == NULL)
		return;
	ff->async_handler.callback_data = NULL;

	/* Release higher 4 bytes of address. */
	reg = cpu_to_le32(0x00000000);
	snd_fw_transaction(ff->unit, TCODE_WRITE_QUADLET_REQUEST,
			   ff->spec->protocol->midi_high_addr_reg,
			   &reg, sizeof(reg), 0);

	fw_core_remove_address_handler(&ff->async_handler);
}