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_sndintpipe(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_urb_ep_type_check(urb);
134	if (retval < 0)
135		goto error;
136
137	retval = usb_submit_urb(urb, GFP_ATOMIC);
138	if (retval < 0)
139		goto error;
140
141	++line6->line6midi->num_active_send_urbs;
142	return 0;
143
144 error:
145	dev_err(line6->ifcdev, "usb_submit_urb failed\n");
146	usb_free_urb(urb);
147	return retval;
148}
149
150static int line6_midi_output_open(struct snd_rawmidi_substream *substream)
151{
152	return 0;
153}
154
155static int line6_midi_output_close(struct snd_rawmidi_substream *substream)
156{
157	return 0;
158}
159
160static void line6_midi_output_trigger(struct snd_rawmidi_substream *substream,
161				      int up)
162{
163	unsigned long flags;
164	struct usb_line6 *line6 =
165	    line6_rawmidi_substream_midi(substream)->line6;
166
167	line6->line6midi->substream_transmit = substream;
168	spin_lock_irqsave(&line6->line6midi->lock, flags);
169
170	if (line6->line6midi->num_active_send_urbs == 0)
171		line6_midi_transmit(substream);
172
173	spin_unlock_irqrestore(&line6->line6midi->lock, flags);
174}
175
176static void line6_midi_output_drain(struct snd_rawmidi_substream *substream)
177{
178	struct usb_line6 *line6 =
179	    line6_rawmidi_substream_midi(substream)->line6;
180	struct snd_line6_midi *midi = line6->line6midi;
181
182	wait_event_interruptible(midi->send_wait,
183				 midi->num_active_send_urbs == 0);
184}
185
186static int line6_midi_input_open(struct snd_rawmidi_substream *substream)
187{
188	return 0;
189}
190
191static int line6_midi_input_close(struct snd_rawmidi_substream *substream)
192{
193	return 0;
194}
195
196static void line6_midi_input_trigger(struct snd_rawmidi_substream *substream,
197				     int up)
198{
199	struct usb_line6 *line6 =
200	    line6_rawmidi_substream_midi(substream)->line6;
201
202	if (up)
203		line6->line6midi->substream_receive = substream;
204	else
205		line6->line6midi->substream_receive = NULL;
206}
207
208static const struct snd_rawmidi_ops line6_midi_output_ops = {
209	.open = line6_midi_output_open,
210	.close = line6_midi_output_close,
211	.trigger = line6_midi_output_trigger,
212	.drain = line6_midi_output_drain,
213};
214
215static const struct snd_rawmidi_ops line6_midi_input_ops = {
216	.open = line6_midi_input_open,
217	.close = line6_midi_input_close,
218	.trigger = line6_midi_input_trigger,
219};
220
221/* Create a MIDI device */
222static int snd_line6_new_midi(struct usb_line6 *line6,
223			      struct snd_rawmidi **rmidi_ret)
224{
225	struct snd_rawmidi *rmidi;
226	int err;
227
228	err = snd_rawmidi_new(line6->card, "Line 6 MIDI", 0, 1, 1, rmidi_ret);
229	if (err < 0)
230		return err;
231
232	rmidi = *rmidi_ret;
233	strcpy(rmidi->id, line6->properties->id);
234	strcpy(rmidi->name, line6->properties->name);
235
236	rmidi->info_flags =
237	    SNDRV_RAWMIDI_INFO_OUTPUT |
238	    SNDRV_RAWMIDI_INFO_INPUT | SNDRV_RAWMIDI_INFO_DUPLEX;
239
240	snd_rawmidi_set_ops(rmidi, SNDRV_RAWMIDI_STREAM_OUTPUT,
241			    &line6_midi_output_ops);
242	snd_rawmidi_set_ops(rmidi, SNDRV_RAWMIDI_STREAM_INPUT,
243			    &line6_midi_input_ops);
244	return 0;
245}
246
247/* MIDI device destructor */
248static void snd_line6_midi_free(struct snd_rawmidi *rmidi)
249{
250	struct snd_line6_midi *line6midi = rmidi->private_data;
251
252	line6_midibuf_destroy(&line6midi->midibuf_in);
253	line6_midibuf_destroy(&line6midi->midibuf_out);
254	kfree(line6midi);
255}
256
257/*
258	Initialize the Line 6 MIDI subsystem.
259*/
260int line6_init_midi(struct usb_line6 *line6)
261{
262	int err;
263	struct snd_rawmidi *rmidi;
264	struct snd_line6_midi *line6midi;
265
266	if (!(line6->properties->capabilities & LINE6_CAP_CONTROL_MIDI)) {
267		/* skip MIDI initialization and report success */
268		return 0;
269	}
270
271	err = snd_line6_new_midi(line6, &rmidi);
272	if (err < 0)
273		return err;
274
275	line6midi = kzalloc(sizeof(struct snd_line6_midi), GFP_KERNEL);
276	if (!line6midi)
277		return -ENOMEM;
278
279	rmidi->private_data = line6midi;
280	rmidi->private_free = snd_line6_midi_free;
281
282	init_waitqueue_head(&line6midi->send_wait);
283	spin_lock_init(&line6midi->lock);
284	line6midi->line6 = line6;
285
286	err = line6_midibuf_init(&line6midi->midibuf_in, MIDI_BUFFER_SIZE, 0);
287	if (err < 0)
288		return err;
289
290	err = line6_midibuf_init(&line6midi->midibuf_out, MIDI_BUFFER_SIZE, 1);
291	if (err < 0)
292		return err;
293
294	line6->line6midi = line6midi;
295	return 0;
296}
297EXPORT_SYMBOL_GPL(line6_init_midi);