drivers/staging/line6/midi.c

   1 /*
   2  * Line6 Linux USB driver - 0.9.1beta
   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 <sound/core.h>
  15 #include <sound/rawmidi.h>
  16
  17 #include "audio.h"
  18 #include "driver.h"
  19 #include "midi.h"
  20 #include "pod.h"
  21 #include "usbdefs.h"
  22
  23 #define line6_rawmidi_substream_midi(substream) \
  24         ((struct snd_line6_midi *)((substream)->rmidi->private_data))
  25
  26 static int send_midi_async(struct usb_line6 *line6, unsigned char *data,
  27                            int length);
  28
  29 /*
  30         Pass data received via USB to MIDI.
  31 */
  32 void line6_midi_receive(struct usb_line6 *line6, unsigned char *data,
  33                         int length)
  34 {
  35         if (line6->line6midi->substream_receive)
  36                 snd_rawmidi_receive(line6->line6midi->substream_receive,
  37                                     data, length);
  38 }
  39
  40 /*
  41         Read data from MIDI buffer and transmit them via USB.
  42 */
  43 static void line6_midi_transmit(struct snd_rawmidi_substream *substream)
  44 {
  45         struct usb_line6 *line6 =
  46             line6_rawmidi_substream_midi(substream)->line6;
  47         struct snd_line6_midi *line6midi = line6->line6midi;
  48         struct midi_buffer *mb = &line6midi->midibuf_out;
  49         unsigned long flags;
  50         unsigned char chunk[line6->max_packet_size];
  51         int req, done;
  52
  53         spin_lock_irqsave(&line6->line6midi->midi_transmit_lock, flags);
  54
  55         for (;;) {
  56                 req = min(line6_midibuf_bytes_free(mb), line6->max_packet_size);
  57                 done = snd_rawmidi_transmit_peek(substream, chunk, req);
  58
  59                 if (done == 0)
  60                         break;
  61
  62                 line6_midibuf_write(mb, chunk, done);
  63                 snd_rawmidi_transmit_ack(substream, done);
  64         }
  65
  66         for (;;) {
  67                 done = line6_midibuf_read(mb, chunk, line6->max_packet_size);
  68
  69                 if (done == 0)
  70                         break;
  71
  72                 send_midi_async(line6, chunk, done);
  73         }
  74
  75         spin_unlock_irqrestore(&line6->line6midi->midi_transmit_lock, flags);
  76 }
  77
  78 /*
  79         Notification of completion of MIDI transmission.
  80 */
  81 static void midi_sent(struct urb *urb)
  82 {
  83         unsigned long flags;
  84         int status;
  85         int num;
  86         struct usb_line6 *line6 = (struct usb_line6 *)urb->context;
  87
  88         status = urb->status;
  89         kfree(urb->transfer_buffer);
  90         usb_free_urb(urb);
  91
  92         if (status == -ESHUTDOWN)
  93                 return;
  94
  95         spin_lock_irqsave(&line6->line6midi->send_urb_lock, flags);
  96         num = --line6->line6midi->num_active_send_urbs;
  97
  98         if (num == 0) {
  99                 line6_midi_transmit(line6->line6midi->substream_transmit);
 100                 num = line6->line6midi->num_active_send_urbs;
 101         }
 102
 103         if (num == 0)
 104                 wake_up(&line6->line6midi->send_wait);
 105
 106         spin_unlock_irqrestore(&line6->line6midi->send_urb_lock, flags);
 107 }
 108
 109 /*
 110         Send an asynchronous MIDI message.
 111         Assumes that line6->line6midi->send_urb_lock is held
 112         (i.e., this function is serialized).
 113 */
 114 static int send_midi_async(struct usb_line6 *line6, unsigned char *data,
 115                            int length)
 116 {
 117         struct urb *urb;
 118         int retval;
 119         unsigned char *transfer_buffer;
 120
 121         urb = usb_alloc_urb(0, GFP_ATOMIC);
 122
 123         if (urb == NULL) {
 124                 dev_err(line6->ifcdev, "Out of memory\n");
 125                 return -ENOMEM;
 126         }
 127
 128         transfer_buffer = kmemdup(data, length, GFP_ATOMIC);
 129
 130         if (transfer_buffer == NULL) {
 131                 usb_free_urb(urb);
 132                 dev_err(line6->ifcdev, "Out of memory\n");
 133                 return -ENOMEM;
 134         }
 135
 136         usb_fill_int_urb(urb, line6->usbdev,
 137                          usb_sndbulkpipe(line6->usbdev,
 138                                          line6->ep_control_write),
 139                          transfer_buffer, length, midi_sent, line6,
 140                          line6->interval);
 141         urb->actual_length = 0;
 142         retval = usb_submit_urb(urb, GFP_ATOMIC);
 143
 144         if (retval < 0) {
 145                 dev_err(line6->ifcdev, "usb_submit_urb failed\n");
 146                 usb_free_urb(urb);
 147                 return retval;
 148         }
 149
 150         ++line6->line6midi->num_active_send_urbs;
 151         return 0;
 152 }
 153
 154 static int line6_midi_output_open(struct snd_rawmidi_substream *substream)
 155 {
 156         return 0;
 157 }
 158
 159 static int line6_midi_output_close(struct snd_rawmidi_substream *substream)
 160 {
 161         return 0;
 162 }
 163
 164 static void line6_midi_output_trigger(struct snd_rawmidi_substream *substream,
 165                                       int up)
 166 {
 167         unsigned long flags;
 168         struct usb_line6 *line6 =
 169             line6_rawmidi_substream_midi(substream)->line6;
 170
 171         line6->line6midi->substream_transmit = substream;
 172         spin_lock_irqsave(&line6->line6midi->send_urb_lock, flags);
 173
 174         if (line6->line6midi->num_active_send_urbs == 0)
 175                 line6_midi_transmit(substream);
 176
 177         spin_unlock_irqrestore(&line6->line6midi->send_urb_lock, flags);
 178 }
 179
 180 static void line6_midi_output_drain(struct snd_rawmidi_substream *substream)
 181 {
 182         struct usb_line6 *line6 =
 183             line6_rawmidi_substream_midi(substream)->line6;
 184         struct snd_line6_midi *midi = line6->line6midi;
 185         wait_event_interruptible(midi->send_wait,
 186                                  midi->num_active_send_urbs == 0);
 187 }
 188
 189 static int line6_midi_input_open(struct snd_rawmidi_substream *substream)
 190 {
 191         return 0;
 192 }
 193
 194 static int line6_midi_input_close(struct snd_rawmidi_substream *substream)
 195 {
 196         return 0;
 197 }
 198
 199 static void line6_midi_input_trigger(struct snd_rawmidi_substream *substream,
 200                                      int up)
 201 {
 202         struct usb_line6 *line6 =
 203             line6_rawmidi_substream_midi(substream)->line6;
 204
 205         if (up)
 206                 line6->line6midi->substream_receive = substream;
 207         else
 208                 line6->line6midi->substream_receive = NULL;
 209 }
 210
 211 static struct snd_rawmidi_ops line6_midi_output_ops = {
 212         .open = line6_midi_output_open,
 213         .close = line6_midi_output_close,
 214         .trigger = line6_midi_output_trigger,
 215         .drain = line6_midi_output_drain,
 216 };
 217
 218 static struct snd_rawmidi_ops line6_midi_input_ops = {
 219         .open = line6_midi_input_open,
 220         .close = line6_midi_input_close,
 221         .trigger = line6_midi_input_trigger,
 222 };
 223
 224 /*
 225         Cleanup the Line6 MIDI device.
 226 */
 227 static void line6_cleanup_midi(struct snd_rawmidi *rmidi)
 228 {
 229 }
 230
 231 /* Create a MIDI device */
 232 static int snd_line6_new_midi(struct snd_line6_midi *line6midi)
 233 {
 234         struct snd_rawmidi *rmidi;
 235         int err;
 236
 237         err = snd_rawmidi_new(line6midi->line6->card, "Line6 MIDI", 0, 1, 1,
 238                               &rmidi);
 239         if (err < 0)
 240                 return err;
 241
 242         rmidi->private_data = line6midi;
 243         rmidi->private_free = line6_cleanup_midi;
 244         strcpy(rmidi->id, line6midi->line6->properties->id);
 245         strcpy(rmidi->name, line6midi->line6->properties->name);
 246
 247         rmidi->info_flags =
 248             SNDRV_RAWMIDI_INFO_OUTPUT |
 249             SNDRV_RAWMIDI_INFO_INPUT | SNDRV_RAWMIDI_INFO_DUPLEX;
 250
 251         snd_rawmidi_set_ops(rmidi, SNDRV_RAWMIDI_STREAM_OUTPUT,
 252                             &line6_midi_output_ops);
 253         snd_rawmidi_set_ops(rmidi, SNDRV_RAWMIDI_STREAM_INPUT,
 254                             &line6_midi_input_ops);
 255         return 0;
 256 }
 257
 258 /* MIDI device destructor */
 259 static int snd_line6_midi_free(struct snd_device *device)
 260 {
 261         struct snd_line6_midi *line6midi = device->device_data;
 262         line6_midibuf_destroy(&line6midi->midibuf_in);
 263         line6_midibuf_destroy(&line6midi->midibuf_out);
 264         return 0;
 265 }
 266
 267 /*
 268         Initialize the Line6 MIDI subsystem.
 269 */
 270 int line6_init_midi(struct usb_line6 *line6)
 271 {
 272         static struct snd_device_ops midi_ops = {
 273                 .dev_free = snd_line6_midi_free,
 274         };
 275
 276         int err;
 277         struct snd_line6_midi *line6midi;
 278
 279         if (!(line6->properties->capabilities & LINE6_BIT_CONTROL)) {
 280                 /* skip MIDI initialization and report success */
 281                 return 0;
 282         }
 283
 284         line6midi = kzalloc(sizeof(struct snd_line6_midi), GFP_KERNEL);
 285
 286         if (line6midi == NULL)
 287                 return -ENOMEM;
 288
 289         err = line6_midibuf_init(&line6midi->midibuf_in, MIDI_BUFFER_SIZE, 0);
 290         if (err < 0) {
 291                 kfree(line6midi);
 292                 return err;
 293         }
 294
 295         err = line6_midibuf_init(&line6midi->midibuf_out, MIDI_BUFFER_SIZE, 1);
 296         if (err < 0) {
 297                 kfree(line6midi->midibuf_in.buf);
 298                 kfree(line6midi);
 299                 return err;
 300         }
 301
 302         line6midi->line6 = line6;
 303         line6->line6midi = line6midi;
 304
 305         err = snd_device_new(line6->card, SNDRV_DEV_RAWMIDI, line6midi,
 306                              &midi_ops);
 307         if (err < 0)
 308                 return err;
 309
 310         snd_card_set_dev(line6->card, line6->ifcdev);
 311
 312         err = snd_line6_new_midi(line6midi);
 313         if (err < 0)
 314                 return err;
 315
 316         init_waitqueue_head(&line6midi->send_wait);
 317         spin_lock_init(&line6midi->send_urb_lock);
 318         spin_lock_init(&line6midi->midi_transmit_lock);
 319         return 0;
 320 }