1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Line 6 Linux USB driver
4 *
5 * Copyright (C) 2004-2010 Markus Grabner (grabner@icg.tugraz.at)
6 */
7
8 #include <linux/slab.h>
9 #include <linux/usb.h>
10 #include <linux/export.h>
11 #include <sound/core.h>
12 #include <sound/rawmidi.h>
13
14 #include "driver.h"
15 #include "midi.h"
16
17 #define line6_rawmidi_substream_midi(substream) \
18 ((struct snd_line6_midi *)((substream)->rmidi->private_data))
19
20 static int send_midi_async(struct usb_line6 *line6, unsigned char *data,
21 int length);
22
23 /*
24 Pass data received via USB to MIDI.
25 */
26 void line6_midi_receive(struct usb_line6 *line6, unsigned char *data,
27 int length)
28 {
29 if (line6->line6midi->substream_receive)
30 snd_rawmidi_receive(line6->line6midi->substream_receive,
31 data, length);
32 }
33
34 /*
35 Read data from MIDI buffer and transmit them via USB.
36 */
37 static void line6_midi_transmit(struct snd_rawmidi_substream *substream)
38 {
39 struct usb_line6 *line6 =
40 line6_rawmidi_substream_midi(substream)->line6;
41 struct snd_line6_midi *line6midi = line6->line6midi;
42 struct midi_buffer *mb = &line6midi->midibuf_out;
43 unsigned char chunk[LINE6_FALLBACK_MAXPACKETSIZE];
44 int req, done;
45
46 for (;;) {
47 req = min3(line6_midibuf_bytes_free(mb), line6->max_packet_size,
48 LINE6_FALLBACK_MAXPACKETSIZE);
49 done = snd_rawmidi_transmit_peek(substream, chunk, req);
50
51 if (done == 0)
52 break;
53
54 line6_midibuf_write(mb, chunk, done);
55 snd_rawmidi_transmit_ack(substream, done);
56 }
57
58 for (;;) {
59 done = line6_midibuf_read(mb, chunk,
60 LINE6_FALLBACK_MAXPACKETSIZE,
61 LINE6_MIDIBUF_READ_TX);
62
63 if (done == 0)
64 break;
65
66 send_midi_async(line6, chunk, done);
67 }
68 }
69
70 /*
71 Notification of completion of MIDI transmission.
72 */
73 static void midi_sent(struct urb *urb)
74 {
75 unsigned long flags;
76 int status;
77 int num;
78 struct usb_line6 *line6 = (struct usb_line6 *)urb->context;
79
80 status = urb->status;
81 kfree(urb->transfer_buffer);
82 usb_free_urb(urb);
83
84 if (status == -ESHUTDOWN)
85 return;
86
87 spin_lock_irqsave(&line6->line6midi->lock, flags);
88 num = --line6->line6midi->num_active_send_urbs;
89
90 if (num == 0) {
91 line6_midi_transmit(line6->line6midi->substream_transmit);
92 num = line6->line6midi->num_active_send_urbs;
93 }
94
95 if (num == 0)
96 wake_up(&line6->line6midi->send_wait);
97
98 spin_unlock_irqrestore(&line6->line6midi->lock, flags);
99 }
100
101 /*
102 Send an asynchronous MIDI message.
103 Assumes that line6->line6midi->lock is held
104 (i.e., this function is serialized).
105 */
106 static int send_midi_async(struct usb_line6 *line6, unsigned char *data,
107 int length)
108 {
109 struct urb *urb;
110 int retval;
111 unsigned char *transfer_buffer;
112
113 urb = usb_alloc_urb(0, GFP_ATOMIC);
114
115 if (urb == NULL)
116 return -ENOMEM;
117
118 transfer_buffer = kmemdup(data, length, GFP_ATOMIC);
119
120 if (transfer_buffer == NULL) {
121 usb_free_urb(urb);
122 return -ENOMEM;
123 }
124
125 usb_fill_int_urb(urb, line6->usbdev,
126 usb_sndintpipe(line6->usbdev,
127 line6->properties->ep_ctrl_w),
128 transfer_buffer, length, midi_sent, line6,
129 line6->interval);
130 urb->actual_length = 0;
131 retval = usb_urb_ep_type_check(urb);
132 if (retval < 0)
133 goto error;
134
135 retval = usb_submit_urb(urb, GFP_ATOMIC);
136 if (retval < 0)
137 goto error;
138
139 ++line6->line6midi->num_active_send_urbs;
140 return 0;
141
142 error:
143 dev_err(line6->ifcdev, "usb_submit_urb failed\n");
144 usb_free_urb(urb);
145 return retval;
146 }
147
148 static int line6_midi_output_open(struct snd_rawmidi_substream *substream)
149 {
150 return 0;
151 }
152
153 static int line6_midi_output_close(struct snd_rawmidi_substream *substream)
154 {
155 return 0;
156 }
157
158 static void line6_midi_output_trigger(struct snd_rawmidi_substream *substream,
159 int up)
160 {
161 unsigned long flags;
162 struct usb_line6 *line6 =
163 line6_rawmidi_substream_midi(substream)->line6;
164
165 line6->line6midi->substream_transmit = substream;
166 spin_lock_irqsave(&line6->line6midi->lock, flags);
167
168 if (line6->line6midi->num_active_send_urbs == 0)
169 line6_midi_transmit(substream);
170
171 spin_unlock_irqrestore(&line6->line6midi->lock, flags);
172 }
173
174 static void line6_midi_output_drain(struct snd_rawmidi_substream *substream)
175 {
176 struct usb_line6 *line6 =
177 line6_rawmidi_substream_midi(substream)->line6;
178 struct snd_line6_midi *midi = line6->line6midi;
179
180 wait_event_interruptible(midi->send_wait,
181 midi->num_active_send_urbs == 0);
182 }
183
184 static int line6_midi_input_open(struct snd_rawmidi_substream *substream)
185 {
186 return 0;
187 }
188
189 static int line6_midi_input_close(struct snd_rawmidi_substream *substream)
190 {
191 return 0;
192 }
193
194 static void line6_midi_input_trigger(struct snd_rawmidi_substream *substream,
195 int up)
196 {
197 struct usb_line6 *line6 =
198 line6_rawmidi_substream_midi(substream)->line6;
199
200 if (up)
201 line6->line6midi->substream_receive = substream;
202 else
203 line6->line6midi->substream_receive = NULL;
204 }
205
206 static const struct snd_rawmidi_ops line6_midi_output_ops = {
207 .open = line6_midi_output_open,
208 .close = line6_midi_output_close,
209 .trigger = line6_midi_output_trigger,
210 .drain = line6_midi_output_drain,
211 };
212
213 static const struct snd_rawmidi_ops line6_midi_input_ops = {
214 .open = line6_midi_input_open,
215 .close = line6_midi_input_close,
216 .trigger = line6_midi_input_trigger,
217 };
218
219 /* Create a MIDI device */
220 static int snd_line6_new_midi(struct usb_line6 *line6,
221 struct snd_rawmidi **rmidi_ret)
222 {
223 struct snd_rawmidi *rmidi;
224 int err;
225
226 err = snd_rawmidi_new(line6->card, "Line 6 MIDI", 0, 1, 1, rmidi_ret);
227 if (err < 0)
228 return err;
229
230 rmidi = *rmidi_ret;
231 strcpy(rmidi->id, line6->properties->id);
232 strcpy(rmidi->name, line6->properties->name);
233
234 rmidi->info_flags =
235 SNDRV_RAWMIDI_INFO_OUTPUT |
236 SNDRV_RAWMIDI_INFO_INPUT | SNDRV_RAWMIDI_INFO_DUPLEX;
237
238 snd_rawmidi_set_ops(rmidi, SNDRV_RAWMIDI_STREAM_OUTPUT,
239 &line6_midi_output_ops);
240 snd_rawmidi_set_ops(rmidi, SNDRV_RAWMIDI_STREAM_INPUT,
241 &line6_midi_input_ops);
242 return 0;
243 }
244
245 /* MIDI device destructor */
246 static void snd_line6_midi_free(struct snd_rawmidi *rmidi)
247 {
248 struct snd_line6_midi *line6midi = rmidi->private_data;
249
250 line6_midibuf_destroy(&line6midi->midibuf_in);
251 line6_midibuf_destroy(&line6midi->midibuf_out);
252 kfree(line6midi);
253 }
254
255 /*
256 Initialize the Line 6 MIDI subsystem.
257 */
258 int line6_init_midi(struct usb_line6 *line6)
259 {
260 int err;
261 struct snd_rawmidi *rmidi;
262 struct snd_line6_midi *line6midi;
263
264 if (!(line6->properties->capabilities & LINE6_CAP_CONTROL_MIDI)) {
265 /* skip MIDI initialization and report success */
266 return 0;
267 }
268
269 err = snd_line6_new_midi(line6, &rmidi);
270 if (err < 0)
271 return err;
272
273 line6midi = kzalloc(sizeof(struct snd_line6_midi), GFP_KERNEL);
274 if (!line6midi)
275 return -ENOMEM;
276
277 rmidi->private_data = line6midi;
278 rmidi->private_free = snd_line6_midi_free;
279
280 init_waitqueue_head(&line6midi->send_wait);
281 spin_lock_init(&line6midi->lock);
282 line6midi->line6 = line6;
283
284 err = line6_midibuf_init(&line6midi->midibuf_in, MIDI_BUFFER_SIZE, 0);
285 if (err < 0)
286 return err;
287
288 err = line6_midibuf_init(&line6midi->midibuf_out, MIDI_BUFFER_SIZE, 1);
289 if (err < 0)
290 return err;
291
292 line6->line6midi = line6midi;
293 return 0;
294 }
295 EXPORT_SYMBOL_GPL(line6_init_midi);
296
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