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
20static 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*/
26void 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*/
37static 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*/
73static 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*/
106static 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
148static int line6_midi_output_open(struct snd_rawmidi_substream *substream)
149{
150	return 0;
151}
152
153static int line6_midi_output_close(struct snd_rawmidi_substream *substream)
154{
155	return 0;
156}
157
158static 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
174static 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
184static int line6_midi_input_open(struct snd_rawmidi_substream *substream)
185{
186	return 0;
187}
188
189static int line6_midi_input_close(struct snd_rawmidi_substream *substream)
190{
191	return 0;
192}
193
194static 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
206static 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
213static 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 */
220static 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 */
246static 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*/
258int 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}
295EXPORT_SYMBOL_GPL(line6_init_midi);
296