1/*
2 * Line 6 Linux USB driver
3 *
4 * Copyright (C) 2004-2010 Markus Grabner (grabner@icg.tugraz.at)
5 *
6 *	This program is free software; you can redistribute it and/or
7 *	modify it under the terms of the GNU General Public License as
8 *	published by the Free Software Foundation, version 2.
9 *
10 */
11
12#include <linux/slab.h>
13#include <linux/usb.h>
14#include <linux/export.h>
15#include <sound/core.h>
16#include <sound/rawmidi.h>
17
18#include "driver.h"
19#include "midi.h"
20
21#define line6_rawmidi_substream_midi(substream) \
22	((struct snd_line6_midi *)((substream)->rmidi->private_data))
23
24static int send_midi_async(struct usb_line6 *line6, unsigned char *data,
25			   int length);
26
27/*
28	Pass data received via USB to MIDI.
29*/
30void line6_midi_receive(struct usb_line6 *line6, unsigned char *data,
31			int length)
32{
33	if (line6->line6midi->substream_receive)
34		snd_rawmidi_receive(line6->line6midi->substream_receive,
35				    data, length);
36}
37
38/*
39	Read data from MIDI buffer and transmit them via USB.
40*/
41static void line6_midi_transmit(struct snd_rawmidi_substream *substream)
42{
43	struct usb_line6 *line6 =
44	    line6_rawmidi_substream_midi(substream)->line6;
45	struct snd_line6_midi *line6midi = line6->line6midi;
46	struct midi_buffer *mb = &line6midi->midibuf_out;
47	unsigned char chunk[LINE6_FALLBACK_MAXPACKETSIZE];
48	int req, done;
49
50	for (;;) {
51		req = min(line6_midibuf_bytes_free(mb), line6->max_packet_size);
52		done = snd_rawmidi_transmit_peek(substream, chunk, req);
53
54		if (done == 0)
55			break;
56
57		line6_midibuf_write(mb, chunk, done);
58		snd_rawmidi_transmit_ack(substream, done);
59	}
60
61	for (;;) {
62		done = line6_midibuf_read(mb, chunk,
63					  LINE6_FALLBACK_MAXPACKETSIZE);
64
65		if (done == 0)
66			break;
67
68		send_midi_async(line6, chunk, done);
69	}
70}
71
72/*
73	Notification of completion of MIDI transmission.
74*/
75static void midi_sent(struct urb *urb)
76{
77	unsigned long flags;
78	int status;
79	int num;
80	struct usb_line6 *line6 = (struct usb_line6 *)urb->context;
81
82	status = urb->status;
83	kfree(urb->transfer_buffer);
84	usb_free_urb(urb);
85
86	if (status == -ESHUTDOWN)
87		return;
88
89	spin_lock_irqsave(&line6->line6midi->lock, flags);
90	num = --line6->line6midi->num_active_send_urbs;
91
92	if (num == 0) {
93		line6_midi_transmit(line6->line6midi->substream_transmit);
94		num = line6->line6midi->num_active_send_urbs;
95	}
96
97	if (num == 0)
98		wake_up(&line6->line6midi->send_wait);
99
100	spin_unlock_irqrestore(&line6->line6midi->lock, flags);
101}
102
103/*
104	Send an asynchronous MIDI message.
105	Assumes that line6->line6midi->lock is held
106	(i.e., this function is serialized).
107*/
108static int send_midi_async(struct usb_line6 *line6, unsigned char *data,
109			   int length)
110{
111	struct urb *urb;
112	int retval;
113	unsigned char *transfer_buffer;
114
115	urb = usb_alloc_urb(0, GFP_ATOMIC);
116
117	if (urb == NULL)
118		return -ENOMEM;
119
120	transfer_buffer = kmemdup(data, length, GFP_ATOMIC);
121
122	if (transfer_buffer == NULL) {
123		usb_free_urb(urb);
124		return -ENOMEM;
125	}
126
127	usb_fill_int_urb(urb, line6->usbdev,
128			 usb_sndbulkpipe(line6->usbdev,
129					 line6->properties->ep_ctrl_w),
130			 transfer_buffer, length, midi_sent, line6,
131			 line6->interval);
132	urb->actual_length = 0;
133	retval = usb_submit_urb(urb, GFP_ATOMIC);
134
135	if (retval < 0) {
136		dev_err(line6->ifcdev, "usb_submit_urb failed\n");
137		usb_free_urb(urb);
138		return retval;
139	}
140
141	++line6->line6midi->num_active_send_urbs;
142	return 0;
143}
144
145static int line6_midi_output_open(struct snd_rawmidi_substream *substream)
146{
147	return 0;
148}
149
150static int line6_midi_output_close(struct snd_rawmidi_substream *substream)
151{
152	return 0;
153}
154
155static void line6_midi_output_trigger(struct snd_rawmidi_substream *substream,
156				      int up)
157{
158	unsigned long flags;
159	struct usb_line6 *line6 =
160	    line6_rawmidi_substream_midi(substream)->line6;
161
162	line6->line6midi->substream_transmit = substream;
163	spin_lock_irqsave(&line6->line6midi->lock, flags);
164
165	if (line6->line6midi->num_active_send_urbs == 0)
166		line6_midi_transmit(substream);
167
168	spin_unlock_irqrestore(&line6->line6midi->lock, flags);
169}
170
171static void line6_midi_output_drain(struct snd_rawmidi_substream *substream)
172{
173	struct usb_line6 *line6 =
174	    line6_rawmidi_substream_midi(substream)->line6;
175	struct snd_line6_midi *midi = line6->line6midi;
176
177	wait_event_interruptible(midi->send_wait,
178				 midi->num_active_send_urbs == 0);
179}
180
181static int line6_midi_input_open(struct snd_rawmidi_substream *substream)
182{
183	return 0;
184}
185
186static int line6_midi_input_close(struct snd_rawmidi_substream *substream)
187{
188	return 0;
189}
190
191static void line6_midi_input_trigger(struct snd_rawmidi_substream *substream,
192				     int up)
193{
194	struct usb_line6 *line6 =
195	    line6_rawmidi_substream_midi(substream)->line6;
196
197	if (up)
198		line6->line6midi->substream_receive = substream;
199	else
200		line6->line6midi->substream_receive = NULL;
201}
202
203static struct snd_rawmidi_ops line6_midi_output_ops = {
204	.open = line6_midi_output_open,
205	.close = line6_midi_output_close,
206	.trigger = line6_midi_output_trigger,
207	.drain = line6_midi_output_drain,
208};
209
210static struct snd_rawmidi_ops line6_midi_input_ops = {
211	.open = line6_midi_input_open,
212	.close = line6_midi_input_close,
213	.trigger = line6_midi_input_trigger,
214};
215
216/* Create a MIDI device */
217static int snd_line6_new_midi(struct usb_line6 *line6,
218			      struct snd_rawmidi **rmidi_ret)
219{
220	struct snd_rawmidi *rmidi;
221	int err;
222
223	err = snd_rawmidi_new(line6->card, "Line 6 MIDI", 0, 1, 1, rmidi_ret);
224	if (err < 0)
225		return err;
226
227	rmidi = *rmidi_ret;
228	strcpy(rmidi->id, line6->properties->id);
229	strcpy(rmidi->name, line6->properties->name);
230
231	rmidi->info_flags =
232	    SNDRV_RAWMIDI_INFO_OUTPUT |
233	    SNDRV_RAWMIDI_INFO_INPUT | SNDRV_RAWMIDI_INFO_DUPLEX;
234
235	snd_rawmidi_set_ops(rmidi, SNDRV_RAWMIDI_STREAM_OUTPUT,
236			    &line6_midi_output_ops);
237	snd_rawmidi_set_ops(rmidi, SNDRV_RAWMIDI_STREAM_INPUT,
238			    &line6_midi_input_ops);
239	return 0;
240}
241
242/* MIDI device destructor */
243static void snd_line6_midi_free(struct snd_rawmidi *rmidi)
244{
245	struct snd_line6_midi *line6midi = rmidi->private_data;
246
247	line6_midibuf_destroy(&line6midi->midibuf_in);
248	line6_midibuf_destroy(&line6midi->midibuf_out);
249	kfree(line6midi);
250}
251
252/*
253	Initialize the Line 6 MIDI subsystem.
254*/
255int line6_init_midi(struct usb_line6 *line6)
256{
257	int err;
258	struct snd_rawmidi *rmidi;
259	struct snd_line6_midi *line6midi;
260
261	if (!(line6->properties->capabilities & LINE6_CAP_CONTROL)) {
262		/* skip MIDI initialization and report success */
263		return 0;
264	}
265
266	err = snd_line6_new_midi(line6, &rmidi);
267	if (err < 0)
268		return err;
269
270	line6midi = kzalloc(sizeof(struct snd_line6_midi), GFP_KERNEL);
271	if (!line6midi)
272		return -ENOMEM;
273
274	rmidi->private_data = line6midi;
275	rmidi->private_free = snd_line6_midi_free;
276
277	init_waitqueue_head(&line6midi->send_wait);
278	spin_lock_init(&line6midi->lock);
279	line6midi->line6 = line6;
280
281	err = line6_midibuf_init(&line6midi->midibuf_in, MIDI_BUFFER_SIZE, 0);
282	if (err < 0)
283		return err;
284
285	err = line6_midibuf_init(&line6midi->midibuf_out, MIDI_BUFFER_SIZE, 1);
286	if (err < 0)
287		return err;
288
289	line6->line6midi = line6midi;
290	return 0;
291}
292EXPORT_SYMBOL_GPL(line6_init_midi);
293