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 24 static 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 */ 30 void 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 */ 41 static 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 */ 75 static 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 */ 108 static 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 } 144 145 static int line6_midi_output_open(struct snd_rawmidi_substream *substream) 146 { 147 return 0; 148 } 149 150 static int line6_midi_output_close(struct snd_rawmidi_substream *substream) 151 { 152 return 0; 153 } 154 155 static 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 } 170 171 static 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 } 180 181 static int line6_midi_input_open(struct snd_rawmidi_substream *substream) 182 { 183 return 0; 184 } 185 186 static int line6_midi_input_close(struct snd_rawmidi_substream *substream) 187 { 188 return 0; 189 } 190 191 static 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 } 202 203 static const 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 }; 209 210 static const 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 */ 217 static 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 */ 243 static 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 */ 255 int 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_MIDI)) { 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 } 292 EXPORT_SYMBOL_GPL(line6_init_midi); 293