sound/usb/bcd2000/bcd2000.c

   1 /*
   2  * Behringer BCD2000 driver
   3  *
   4  *   Copyright (C) 2014 Mario Kicherer (dev@kicherer.org)
   5  *
   6  *   This program is free software; you can redistribute it and/or modify
   7  *   it under the terms of the GNU General Public License as published by
   8  *   the Free Software Foundation; either version 2 of the License, or
   9  *   (at your option) any later version.
  10  *
  11  *   This program is distributed in the hope that it will be useful,
  12  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  *   GNU General Public License for more details.
  15  */
  16
  17 #include <linux/kernel.h>
  18 #include <linux/errno.h>
  19 #include <linux/init.h>
  20 #include <linux/slab.h>
  21 #include <linux/module.h>
  22 #include <linux/bitmap.h>
  23 #include <linux/usb.h>
  24 #include <linux/usb/audio.h>
  25 #include <sound/core.h>
  26 #include <sound/initval.h>
  27 #include <sound/rawmidi.h>
  28
  29 #define PREFIX "snd-bcd2000: "
  30 #define BUFSIZE 64
  31
  32 static const struct usb_device_id id_table[] = {
  33         { USB_DEVICE(0x1397, 0x00bd) },
  34         { },
  35 };
  36
  37 static unsigned char device_cmd_prefix[] = {0x03, 0x00};
  38
  39 static unsigned char bcd2000_init_sequence[] = {
  40         0x07, 0x00, 0x00, 0x00, 0x78, 0x48, 0x1c, 0x81,
  41         0xc4, 0x00, 0x00, 0x00, 0x5e, 0x53, 0x4a, 0xf7,
  42         0x18, 0xfa, 0x11, 0xff, 0x6c, 0xf3, 0x90, 0xff,
  43         0x00, 0x00, 0x00, 0x00, 0x01, 0x00, 0x00, 0x00,
  44         0x18, 0xfa, 0x11, 0xff, 0x14, 0x00, 0x00, 0x00,
  45         0x00, 0x00, 0x00, 0x00, 0xf2, 0x34, 0x4a, 0xf7,
  46         0x18, 0xfa, 0x11, 0xff
  47 };
  48
  49 struct bcd2000 {
  50         struct usb_device *dev;
  51         struct snd_card *card;
  52         struct usb_interface *intf;
  53         int card_index;
  54
  55         int midi_out_active;
  56         struct snd_rawmidi *rmidi;
  57         struct snd_rawmidi_substream *midi_receive_substream;
  58         struct snd_rawmidi_substream *midi_out_substream;
  59
  60         unsigned char midi_in_buf[BUFSIZE];
  61         unsigned char midi_out_buf[BUFSIZE];
  62
  63         struct urb *midi_out_urb;
  64         struct urb *midi_in_urb;
  65
  66         struct usb_anchor anchor;
  67 };
  68
  69 static int index[SNDRV_CARDS] = SNDRV_DEFAULT_IDX;
  70 static char *id[SNDRV_CARDS] = SNDRV_DEFAULT_STR;
  71
  72 static DEFINE_MUTEX(devices_mutex);
  73 static DECLARE_BITMAP(devices_used, SNDRV_CARDS);
  74 static struct usb_driver bcd2000_driver;
  75
  76 #ifdef CONFIG_SND_DEBUG
  77 static void bcd2000_dump_buffer(const char *prefix, const char *buf, int len)
  78 {
  79         print_hex_dump(KERN_DEBUG, prefix,
  80                         DUMP_PREFIX_NONE, 16, 1,
  81                         buf, len, false);
  82 }
  83 #else
  84 static void bcd2000_dump_buffer(const char *prefix, const char *buf, int len) {}
  85 #endif
  86
  87 static int bcd2000_midi_input_open(struct snd_rawmidi_substream *substream)
  88 {
  89         return 0;
  90 }
  91
  92 static int bcd2000_midi_input_close(struct snd_rawmidi_substream *substream)
  93 {
  94         return 0;
  95 }
  96
  97 /* (de)register midi substream from client */
  98 static void bcd2000_midi_input_trigger(struct snd_rawmidi_substream *substream,
  99                                                 int up)
 100 {
 101         struct bcd2000 *bcd2k = substream->rmidi->private_data;
 102         bcd2k->midi_receive_substream = up ? substream : NULL;
 103 }
 104
 105 static void bcd2000_midi_handle_input(struct bcd2000 *bcd2k,
 106                                 const unsigned char *buf, unsigned int buf_len)
 107 {
 108         unsigned int payload_length, tocopy;
 109         struct snd_rawmidi_substream *midi_receive_substream;
 110
 111         midi_receive_substream = READ_ONCE(bcd2k->midi_receive_substream);
 112         if (!midi_receive_substream)
 113                 return;
 114
 115         bcd2000_dump_buffer(PREFIX "received from device: ", buf, buf_len);
 116
 117         if (buf_len < 2)
 118                 return;
 119
 120         payload_length = buf[0];
 121
 122         /* ignore packets without payload */
 123         if (payload_length == 0)
 124                 return;
 125
 126         tocopy = min(payload_length, buf_len-1);
 127
 128         bcd2000_dump_buffer(PREFIX "sending to userspace: ",
 129                                         &buf[1], tocopy);
 130
 131         snd_rawmidi_receive(midi_receive_substream,
 132                                         &buf[1], tocopy);
 133 }
 134
 135 static void bcd2000_midi_send(struct bcd2000 *bcd2k)
 136 {
 137         int len, ret;
 138         struct snd_rawmidi_substream *midi_out_substream;
 139
 140         BUILD_BUG_ON(sizeof(device_cmd_prefix) >= BUFSIZE);
 141
 142         midi_out_substream = READ_ONCE(bcd2k->midi_out_substream);
 143         if (!midi_out_substream)
 144                 return;
 145
 146         /* copy command prefix bytes */
 147         memcpy(bcd2k->midi_out_buf, device_cmd_prefix,
 148                 sizeof(device_cmd_prefix));
 149
 150         /*
 151          * get MIDI packet and leave space for command prefix
 152          * and payload length
 153          */
 154         len = snd_rawmidi_transmit(midi_out_substream,
 155                                 bcd2k->midi_out_buf + 3, BUFSIZE - 3);
 156
 157         if (len < 0)
 158                 dev_err(&bcd2k->dev->dev, "%s: snd_rawmidi_transmit error %d\n",
 159                                 __func__, len);
 160
 161         if (len <= 0)
 162                 return;
 163
 164         /* set payload length */
 165         bcd2k->midi_out_buf[2] = len;
 166         bcd2k->midi_out_urb->transfer_buffer_length = BUFSIZE;
 167
 168         bcd2000_dump_buffer(PREFIX "sending to device: ",
 169                         bcd2k->midi_out_buf, len+3);
 170
 171         /* send packet to the BCD2000 */
 172         ret = usb_submit_urb(bcd2k->midi_out_urb, GFP_ATOMIC);
 173         if (ret < 0)
 174                 dev_err(&bcd2k->dev->dev, PREFIX
 175                         "%s (%p): usb_submit_urb() failed, ret=%d, len=%d\n",
 176                         __func__, midi_out_substream, ret, len);
 177         else
 178                 bcd2k->midi_out_active = 1;
 179 }
 180
 181 static int bcd2000_midi_output_open(struct snd_rawmidi_substream *substream)
 182 {
 183         return 0;
 184 }
 185
 186 static int bcd2000_midi_output_close(struct snd_rawmidi_substream *substream)
 187 {
 188         struct bcd2000 *bcd2k = substream->rmidi->private_data;
 189
 190         if (bcd2k->midi_out_active) {
 191                 usb_kill_urb(bcd2k->midi_out_urb);
 192                 bcd2k->midi_out_active = 0;
 193         }
 194
 195         return 0;
 196 }
 197
 198 /* (de)register midi substream from client */
 199 static void bcd2000_midi_output_trigger(struct snd_rawmidi_substream *substream,
 200                                                 int up)
 201 {
 202         struct bcd2000 *bcd2k = substream->rmidi->private_data;
 203
 204         if (up) {
 205                 bcd2k->midi_out_substream = substream;
 206                 /* check if there is data userspace wants to send */
 207                 if (!bcd2k->midi_out_active)
 208                         bcd2000_midi_send(bcd2k);
 209         } else {
 210                 bcd2k->midi_out_substream = NULL;
 211         }
 212 }
 213
 214 static void bcd2000_output_complete(struct urb *urb)
 215 {
 216         struct bcd2000 *bcd2k = urb->context;
 217
 218         bcd2k->midi_out_active = 0;
 219
 220         if (urb->status)
 221                 dev_warn(&urb->dev->dev,
 222                         PREFIX "output urb->status: %d\n", urb->status);
 223
 224         if (urb->status == -ESHUTDOWN)
 225                 return;
 226
 227         /* check if there is more data userspace wants to send */
 228         bcd2000_midi_send(bcd2k);
 229 }
 230
 231 static void bcd2000_input_complete(struct urb *urb)
 232 {
 233         int ret;
 234         struct bcd2000 *bcd2k = urb->context;
 235
 236         if (urb->status)
 237                 dev_warn(&urb->dev->dev,
 238                         PREFIX "input urb->status: %i\n", urb->status);
 239
 240         if (!bcd2k || urb->status == -ESHUTDOWN)
 241                 return;
 242
 243         if (urb->actual_length > 0)
 244                 bcd2000_midi_handle_input(bcd2k, urb->transfer_buffer,
 245                                         urb->actual_length);
 246
 247         /* return URB to device */
 248         ret = usb_submit_urb(bcd2k->midi_in_urb, GFP_ATOMIC);
 249         if (ret < 0)
 250                 dev_err(&bcd2k->dev->dev, PREFIX
 251                         "%s: usb_submit_urb() failed, ret=%d\n",
 252                         __func__, ret);
 253 }
 254
 255 static const struct snd_rawmidi_ops bcd2000_midi_output = {
 256         .open =    bcd2000_midi_output_open,
 257         .close =   bcd2000_midi_output_close,
 258         .trigger = bcd2000_midi_output_trigger,
 259 };
 260
 261 static const struct snd_rawmidi_ops bcd2000_midi_input = {
 262         .open =    bcd2000_midi_input_open,
 263         .close =   bcd2000_midi_input_close,
 264         .trigger = bcd2000_midi_input_trigger,
 265 };
 266
 267 static void bcd2000_init_device(struct bcd2000 *bcd2k)
 268 {
 269         int ret;
 270
 271         init_usb_anchor(&bcd2k->anchor);
 272         usb_anchor_urb(bcd2k->midi_out_urb, &bcd2k->anchor);
 273         usb_anchor_urb(bcd2k->midi_in_urb, &bcd2k->anchor);
 274
 275         /* copy init sequence into buffer */
 276         memcpy(bcd2k->midi_out_buf, bcd2000_init_sequence, 52);
 277         bcd2k->midi_out_urb->transfer_buffer_length = 52;
 278
 279         /* submit sequence */
 280         ret = usb_submit_urb(bcd2k->midi_out_urb, GFP_KERNEL);
 281         if (ret < 0)
 282                 dev_err(&bcd2k->dev->dev, PREFIX
 283                         "%s: usb_submit_urb() out failed, ret=%d: ",
 284                         __func__, ret);
 285         else
 286                 bcd2k->midi_out_active = 1;
 287
 288         /* pass URB to device to enable button and controller events */
 289         ret = usb_submit_urb(bcd2k->midi_in_urb, GFP_KERNEL);
 290         if (ret < 0)
 291                 dev_err(&bcd2k->dev->dev, PREFIX
 292                         "%s: usb_submit_urb() in failed, ret=%d: ",
 293                         __func__, ret);
 294
 295         /* ensure initialization is finished */
 296         usb_wait_anchor_empty_timeout(&bcd2k->anchor, 1000);
 297 }
 298
 299 static int bcd2000_init_midi(struct bcd2000 *bcd2k)
 300 {
 301         int ret;
 302         struct snd_rawmidi *rmidi;
 303
 304         ret = snd_rawmidi_new(bcd2k->card, bcd2k->card->shortname, 0,
 305                                         1, /* output */
 306                                         1, /* input */
 307                                         &rmidi);
 308
 309         if (ret < 0)
 310                 return ret;
 311
 312         strlcpy(rmidi->name, bcd2k->card->shortname, sizeof(rmidi->name));
 313
 314         rmidi->info_flags = SNDRV_RAWMIDI_INFO_DUPLEX;
 315         rmidi->private_data = bcd2k;
 316
 317         rmidi->info_flags |= SNDRV_RAWMIDI_INFO_OUTPUT;
 318         snd_rawmidi_set_ops(rmidi, SNDRV_RAWMIDI_STREAM_OUTPUT,
 319                                         &bcd2000_midi_output);
 320
 321         rmidi->info_flags |= SNDRV_RAWMIDI_INFO_INPUT;
 322         snd_rawmidi_set_ops(rmidi, SNDRV_RAWMIDI_STREAM_INPUT,
 323                                         &bcd2000_midi_input);
 324
 325         bcd2k->rmidi = rmidi;
 326
 327         bcd2k->midi_in_urb = usb_alloc_urb(0, GFP_KERNEL);
 328         bcd2k->midi_out_urb = usb_alloc_urb(0, GFP_KERNEL);
 329
 330         if (!bcd2k->midi_in_urb || !bcd2k->midi_out_urb) {
 331                 dev_err(&bcd2k->dev->dev, PREFIX "usb_alloc_urb failed\n");
 332                 return -ENOMEM;
 333         }
 334
 335         usb_fill_int_urb(bcd2k->midi_in_urb, bcd2k->dev,
 336                                 usb_rcvintpipe(bcd2k->dev, 0x81),
 337                                 bcd2k->midi_in_buf, BUFSIZE,
 338                                 bcd2000_input_complete, bcd2k, 1);
 339
 340         usb_fill_int_urb(bcd2k->midi_out_urb, bcd2k->dev,
 341                                 usb_sndintpipe(bcd2k->dev, 0x1),
 342                                 bcd2k->midi_out_buf, BUFSIZE,
 343                                 bcd2000_output_complete, bcd2k, 1);
 344
 345         /* sanity checks of EPs before actually submitting */
 346         if (usb_urb_ep_type_check(bcd2k->midi_in_urb) ||
 347             usb_urb_ep_type_check(bcd2k->midi_out_urb)) {
 348                 dev_err(&bcd2k->dev->dev, "invalid MIDI EP\n");
 349                 return -EINVAL;
 350         }
 351
 352         bcd2000_init_device(bcd2k);
 353
 354         return 0;
 355 }
 356
 357 static void bcd2000_free_usb_related_resources(struct bcd2000 *bcd2k,
 358                                                 struct usb_interface *interface)
 359 {
 360         /* usb_kill_urb not necessary, urb is aborted automatically */
 361
 362         usb_free_urb(bcd2k->midi_out_urb);
 363         usb_free_urb(bcd2k->midi_in_urb);
 364
 365         if (bcd2k->intf) {
 366                 usb_set_intfdata(bcd2k->intf, NULL);
 367                 bcd2k->intf = NULL;
 368         }
 369 }
 370
 371 static int bcd2000_probe(struct usb_interface *interface,
 372                                 const struct usb_device_id *usb_id)
 373 {
 374         struct snd_card *card;
 375         struct bcd2000 *bcd2k;
 376         unsigned int card_index;
 377         char usb_path[32];
 378         int err;
 379
 380         mutex_lock(&devices_mutex);
 381
 382         for (card_index = 0; card_index < SNDRV_CARDS; ++card_index)
 383                 if (!test_bit(card_index, devices_used))
 384                         break;
 385
 386         if (card_index >= SNDRV_CARDS) {
 387                 mutex_unlock(&devices_mutex);
 388                 return -ENOENT;
 389         }
 390
 391         err = snd_card_new(&interface->dev, index[card_index], id[card_index],
 392                         THIS_MODULE, sizeof(*bcd2k), &card);
 393         if (err < 0) {
 394                 mutex_unlock(&devices_mutex);
 395                 return err;
 396         }
 397
 398         bcd2k = card->private_data;
 399         bcd2k->dev = interface_to_usbdev(interface);
 400         bcd2k->card = card;
 401         bcd2k->card_index = card_index;
 402         bcd2k->intf = interface;
 403
 404         snd_card_set_dev(card, &interface->dev);
 405
 406         strncpy(card->driver, "snd-bcd2000", sizeof(card->driver));
 407         strncpy(card->shortname, "BCD2000", sizeof(card->shortname));
 408         usb_make_path(bcd2k->dev, usb_path, sizeof(usb_path));
 409         snprintf(bcd2k->card->longname, sizeof(bcd2k->card->longname),
 410                     "Behringer BCD2000 at %s",
 411                         usb_path);
 412
 413         err = bcd2000_init_midi(bcd2k);
 414         if (err < 0)
 415                 goto probe_error;
 416
 417         err = snd_card_register(card);
 418         if (err < 0)
 419                 goto probe_error;
 420
 421         usb_set_intfdata(interface, bcd2k);
 422         set_bit(card_index, devices_used);
 423
 424         mutex_unlock(&devices_mutex);
 425         return 0;
 426
 427 probe_error:
 428         dev_info(&bcd2k->dev->dev, PREFIX "error during probing");
 429         bcd2000_free_usb_related_resources(bcd2k, interface);
 430         snd_card_free(card);
 431         mutex_unlock(&devices_mutex);
 432         return err;
 433 }
 434
 435 static void bcd2000_disconnect(struct usb_interface *interface)
 436 {
 437         struct bcd2000 *bcd2k = usb_get_intfdata(interface);
 438
 439         if (!bcd2k)
 440                 return;
 441
 442         mutex_lock(&devices_mutex);
 443
 444         /* make sure that userspace cannot create new requests */
 445         snd_card_disconnect(bcd2k->card);
 446
 447         bcd2000_free_usb_related_resources(bcd2k, interface);
 448
 449         clear_bit(bcd2k->card_index, devices_used);
 450
 451         snd_card_free_when_closed(bcd2k->card);
 452
 453         mutex_unlock(&devices_mutex);
 454 }
 455
 456 static struct usb_driver bcd2000_driver = {
 457         .name =         "snd-bcd2000",
 458         .probe =        bcd2000_probe,
 459         .disconnect =   bcd2000_disconnect,
 460         .id_table =     id_table,
 461 };
 462
 463 module_usb_driver(bcd2000_driver);
 464
 465 MODULE_DEVICE_TABLE(usb, id_table);
 466 MODULE_AUTHOR("Mario Kicherer, dev@kicherer.org");
 467 MODULE_DESCRIPTION("Behringer BCD2000 driver");
 468 MODULE_LICENSE("GPL");