sound/usb/bcd2000/bcd2000.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * Behringer BCD2000 driver
   4  *
   5  *   Copyright (C) 2014 Mario Kicherer (dev@kicherer.org)
   6  */
   7
   8 #include <linux/kernel.h>
   9 #include <linux/errno.h>
  10 #include <linux/init.h>
  11 #include <linux/slab.h>
  12 #include <linux/module.h>
  13 #include <linux/bitmap.h>
  14 #include <linux/usb.h>
  15 #include <linux/usb/audio.h>
  16 #include <sound/core.h>
  17 #include <sound/initval.h>
  18 #include <sound/rawmidi.h>
  19
  20 #define PREFIX "snd-bcd2000: "
  21 #define BUFSIZE 64
  22
  23 static const struct usb_device_id id_table[] = {
  24         { USB_DEVICE(0x1397, 0x00bd) },
  25         { },
  26 };
  27
  28 static const unsigned char device_cmd_prefix[] = {0x03, 0x00};
  29
  30 static const unsigned char bcd2000_init_sequence[] = {
  31         0x07, 0x00, 0x00, 0x00, 0x78, 0x48, 0x1c, 0x81,
  32         0xc4, 0x00, 0x00, 0x00, 0x5e, 0x53, 0x4a, 0xf7,
  33         0x18, 0xfa, 0x11, 0xff, 0x6c, 0xf3, 0x90, 0xff,
  34         0x00, 0x00, 0x00, 0x00, 0x01, 0x00, 0x00, 0x00,
  35         0x18, 0xfa, 0x11, 0xff, 0x14, 0x00, 0x00, 0x00,
  36         0x00, 0x00, 0x00, 0x00, 0xf2, 0x34, 0x4a, 0xf7,
  37         0x18, 0xfa, 0x11, 0xff
  38 };
  39
  40 struct bcd2000 {
  41         struct usb_device *dev;
  42         struct snd_card *card;
  43         struct usb_interface *intf;
  44         int card_index;
  45
  46         int midi_out_active;
  47         struct snd_rawmidi *rmidi;
  48         struct snd_rawmidi_substream *midi_receive_substream;
  49         struct snd_rawmidi_substream *midi_out_substream;
  50
  51         unsigned char midi_in_buf[BUFSIZE];
  52         unsigned char midi_out_buf[BUFSIZE];
  53
  54         struct urb *midi_out_urb;
  55         struct urb *midi_in_urb;
  56
  57         struct usb_anchor anchor;
  58 };
  59
  60 static int index[SNDRV_CARDS] = SNDRV_DEFAULT_IDX;
  61 static char *id[SNDRV_CARDS] = SNDRV_DEFAULT_STR;
  62
  63 static DEFINE_MUTEX(devices_mutex);
  64 static DECLARE_BITMAP(devices_used, SNDRV_CARDS);
  65 static struct usb_driver bcd2000_driver;
  66
  67 #ifdef CONFIG_SND_DEBUG
  68 static void bcd2000_dump_buffer(const char *prefix, const char *buf, int len)
  69 {
  70         print_hex_dump(KERN_DEBUG, prefix,
  71                         DUMP_PREFIX_NONE, 16, 1,
  72                         buf, len, false);
  73 }
  74 #else
  75 static void bcd2000_dump_buffer(const char *prefix, const char *buf, int len) {}
  76 #endif
  77
  78 static int bcd2000_midi_input_open(struct snd_rawmidi_substream *substream)
  79 {
  80         return 0;
  81 }
  82
  83 static int bcd2000_midi_input_close(struct snd_rawmidi_substream *substream)
  84 {
  85         return 0;
  86 }
  87
  88 /* (de)register midi substream from client */
  89 static void bcd2000_midi_input_trigger(struct snd_rawmidi_substream *substream,
  90                                                 int up)
  91 {
  92         struct bcd2000 *bcd2k = substream->rmidi->private_data;
  93         bcd2k->midi_receive_substream = up ? substream : NULL;
  94 }
  95
  96 static void bcd2000_midi_handle_input(struct bcd2000 *bcd2k,
  97                                 const unsigned char *buf, unsigned int buf_len)
  98 {
  99         unsigned int payload_length, tocopy;
 100         struct snd_rawmidi_substream *midi_receive_substream;
 101
 102         midi_receive_substream = READ_ONCE(bcd2k->midi_receive_substream);
 103         if (!midi_receive_substream)
 104                 return;
 105
 106         bcd2000_dump_buffer(PREFIX "received from device: ", buf, buf_len);
 107
 108         if (buf_len < 2)
 109                 return;
 110
 111         payload_length = buf[0];
 112
 113         /* ignore packets without payload */
 114         if (payload_length == 0)
 115                 return;
 116
 117         tocopy = min(payload_length, buf_len-1);
 118
 119         bcd2000_dump_buffer(PREFIX "sending to userspace: ",
 120                                         &buf[1], tocopy);
 121
 122         snd_rawmidi_receive(midi_receive_substream,
 123                                         &buf[1], tocopy);
 124 }
 125
 126 static void bcd2000_midi_send(struct bcd2000 *bcd2k)
 127 {
 128         int len, ret;
 129         struct snd_rawmidi_substream *midi_out_substream;
 130
 131         BUILD_BUG_ON(sizeof(device_cmd_prefix) >= BUFSIZE);
 132
 133         midi_out_substream = READ_ONCE(bcd2k->midi_out_substream);
 134         if (!midi_out_substream)
 135                 return;
 136
 137         /* copy command prefix bytes */
 138         memcpy(bcd2k->midi_out_buf, device_cmd_prefix,
 139                 sizeof(device_cmd_prefix));
 140
 141         /*
 142          * get MIDI packet and leave space for command prefix
 143          * and payload length
 144          */
 145         len = snd_rawmidi_transmit(midi_out_substream,
 146                                 bcd2k->midi_out_buf + 3, BUFSIZE - 3);
 147
 148         if (len < 0)
 149                 dev_err(&bcd2k->dev->dev, "%s: snd_rawmidi_transmit error %d\n",
 150                                 __func__, len);
 151
 152         if (len <= 0)
 153                 return;
 154
 155         /* set payload length */
 156         bcd2k->midi_out_buf[2] = len;
 157         bcd2k->midi_out_urb->transfer_buffer_length = BUFSIZE;
 158
 159         bcd2000_dump_buffer(PREFIX "sending to device: ",
 160                         bcd2k->midi_out_buf, len+3);
 161
 162         /* send packet to the BCD2000 */
 163         ret = usb_submit_urb(bcd2k->midi_out_urb, GFP_ATOMIC);
 164         if (ret < 0)
 165                 dev_err(&bcd2k->dev->dev, PREFIX
 166                         "%s (%p): usb_submit_urb() failed, ret=%d, len=%d\n",
 167                         __func__, midi_out_substream, ret, len);
 168         else
 169                 bcd2k->midi_out_active = 1;
 170 }
 171
 172 static int bcd2000_midi_output_open(struct snd_rawmidi_substream *substream)
 173 {
 174         return 0;
 175 }
 176
 177 static int bcd2000_midi_output_close(struct snd_rawmidi_substream *substream)
 178 {
 179         struct bcd2000 *bcd2k = substream->rmidi->private_data;
 180
 181         if (bcd2k->midi_out_active) {
 182                 usb_kill_urb(bcd2k->midi_out_urb);
 183                 bcd2k->midi_out_active = 0;
 184         }
 185
 186         return 0;
 187 }
 188
 189 /* (de)register midi substream from client */
 190 static void bcd2000_midi_output_trigger(struct snd_rawmidi_substream *substream,
 191                                                 int up)
 192 {
 193         struct bcd2000 *bcd2k = substream->rmidi->private_data;
 194
 195         if (up) {
 196                 bcd2k->midi_out_substream = substream;
 197                 /* check if there is data userspace wants to send */
 198                 if (!bcd2k->midi_out_active)
 199                         bcd2000_midi_send(bcd2k);
 200         } else {
 201                 bcd2k->midi_out_substream = NULL;
 202         }
 203 }
 204
 205 static void bcd2000_output_complete(struct urb *urb)
 206 {
 207         struct bcd2000 *bcd2k = urb->context;
 208
 209         bcd2k->midi_out_active = 0;
 210
 211         if (urb->status)
 212                 dev_warn(&urb->dev->dev,
 213                         PREFIX "output urb->status: %d\n", urb->status);
 214
 215         if (urb->status == -ESHUTDOWN)
 216                 return;
 217
 218         /* check if there is more data userspace wants to send */
 219         bcd2000_midi_send(bcd2k);
 220 }
 221
 222 static void bcd2000_input_complete(struct urb *urb)
 223 {
 224         int ret;
 225         struct bcd2000 *bcd2k = urb->context;
 226
 227         if (urb->status)
 228                 dev_warn(&urb->dev->dev,
 229                         PREFIX "input urb->status: %i\n", urb->status);
 230
 231         if (!bcd2k || urb->status == -ESHUTDOWN)
 232                 return;
 233
 234         if (urb->actual_length > 0)
 235                 bcd2000_midi_handle_input(bcd2k, urb->transfer_buffer,
 236                                         urb->actual_length);
 237
 238         /* return URB to device */
 239         ret = usb_submit_urb(bcd2k->midi_in_urb, GFP_ATOMIC);
 240         if (ret < 0)
 241                 dev_err(&bcd2k->dev->dev, PREFIX
 242                         "%s: usb_submit_urb() failed, ret=%d\n",
 243                         __func__, ret);
 244 }
 245
 246 static const struct snd_rawmidi_ops bcd2000_midi_output = {
 247         .open =    bcd2000_midi_output_open,
 248         .close =   bcd2000_midi_output_close,
 249         .trigger = bcd2000_midi_output_trigger,
 250 };
 251
 252 static const struct snd_rawmidi_ops bcd2000_midi_input = {
 253         .open =    bcd2000_midi_input_open,
 254         .close =   bcd2000_midi_input_close,
 255         .trigger = bcd2000_midi_input_trigger,
 256 };
 257
 258 static void bcd2000_init_device(struct bcd2000 *bcd2k)
 259 {
 260         int ret;
 261
 262         init_usb_anchor(&bcd2k->anchor);
 263         usb_anchor_urb(bcd2k->midi_out_urb, &bcd2k->anchor);
 264         usb_anchor_urb(bcd2k->midi_in_urb, &bcd2k->anchor);
 265
 266         /* copy init sequence into buffer */
 267         memcpy(bcd2k->midi_out_buf, bcd2000_init_sequence, 52);
 268         bcd2k->midi_out_urb->transfer_buffer_length = 52;
 269
 270         /* submit sequence */
 271         ret = usb_submit_urb(bcd2k->midi_out_urb, GFP_KERNEL);
 272         if (ret < 0)
 273                 dev_err(&bcd2k->dev->dev, PREFIX
 274                         "%s: usb_submit_urb() out failed, ret=%d: ",
 275                         __func__, ret);
 276         else
 277                 bcd2k->midi_out_active = 1;
 278
 279         /* pass URB to device to enable button and controller events */
 280         ret = usb_submit_urb(bcd2k->midi_in_urb, GFP_KERNEL);
 281         if (ret < 0)
 282                 dev_err(&bcd2k->dev->dev, PREFIX
 283                         "%s: usb_submit_urb() in failed, ret=%d: ",
 284                         __func__, ret);
 285
 286         /* ensure initialization is finished */
 287         usb_wait_anchor_empty_timeout(&bcd2k->anchor, 1000);
 288 }
 289
 290 static int bcd2000_init_midi(struct bcd2000 *bcd2k)
 291 {
 292         int ret;
 293         struct snd_rawmidi *rmidi;
 294
 295         ret = snd_rawmidi_new(bcd2k->card, bcd2k->card->shortname, 0,
 296                                         1, /* output */
 297                                         1, /* input */
 298                                         &rmidi);
 299
 300         if (ret < 0)
 301                 return ret;
 302
 303         strlcpy(rmidi->name, bcd2k->card->shortname, sizeof(rmidi->name));
 304
 305         rmidi->info_flags = SNDRV_RAWMIDI_INFO_DUPLEX;
 306         rmidi->private_data = bcd2k;
 307
 308         rmidi->info_flags |= SNDRV_RAWMIDI_INFO_OUTPUT;
 309         snd_rawmidi_set_ops(rmidi, SNDRV_RAWMIDI_STREAM_OUTPUT,
 310                                         &bcd2000_midi_output);
 311
 312         rmidi->info_flags |= SNDRV_RAWMIDI_INFO_INPUT;
 313         snd_rawmidi_set_ops(rmidi, SNDRV_RAWMIDI_STREAM_INPUT,
 314                                         &bcd2000_midi_input);
 315
 316         bcd2k->rmidi = rmidi;
 317
 318         bcd2k->midi_in_urb = usb_alloc_urb(0, GFP_KERNEL);
 319         bcd2k->midi_out_urb = usb_alloc_urb(0, GFP_KERNEL);
 320
 321         if (!bcd2k->midi_in_urb || !bcd2k->midi_out_urb) {
 322                 dev_err(&bcd2k->dev->dev, PREFIX "usb_alloc_urb failed\n");
 323                 return -ENOMEM;
 324         }
 325
 326         usb_fill_int_urb(bcd2k->midi_in_urb, bcd2k->dev,
 327                                 usb_rcvintpipe(bcd2k->dev, 0x81),
 328                                 bcd2k->midi_in_buf, BUFSIZE,
 329                                 bcd2000_input_complete, bcd2k, 1);
 330
 331         usb_fill_int_urb(bcd2k->midi_out_urb, bcd2k->dev,
 332                                 usb_sndintpipe(bcd2k->dev, 0x1),
 333                                 bcd2k->midi_out_buf, BUFSIZE,
 334                                 bcd2000_output_complete, bcd2k, 1);
 335
 336         /* sanity checks of EPs before actually submitting */
 337         if (usb_urb_ep_type_check(bcd2k->midi_in_urb) ||
 338             usb_urb_ep_type_check(bcd2k->midi_out_urb)) {
 339                 dev_err(&bcd2k->dev->dev, "invalid MIDI EP\n");
 340                 return -EINVAL;
 341         }
 342
 343         bcd2000_init_device(bcd2k);
 344
 345         return 0;
 346 }
 347
 348 static void bcd2000_free_usb_related_resources(struct bcd2000 *bcd2k,
 349                                                 struct usb_interface *interface)
 350 {
 351         /* usb_kill_urb not necessary, urb is aborted automatically */
 352
 353         usb_free_urb(bcd2k->midi_out_urb);
 354         usb_free_urb(bcd2k->midi_in_urb);
 355
 356         if (bcd2k->intf) {
 357                 usb_set_intfdata(bcd2k->intf, NULL);
 358                 bcd2k->intf = NULL;
 359         }
 360 }
 361
 362 static int bcd2000_probe(struct usb_interface *interface,
 363                                 const struct usb_device_id *usb_id)
 364 {
 365         struct snd_card *card;
 366         struct bcd2000 *bcd2k;
 367         unsigned int card_index;
 368         char usb_path[32];
 369         int err;
 370
 371         mutex_lock(&devices_mutex);
 372
 373         for (card_index = 0; card_index < SNDRV_CARDS; ++card_index)
 374                 if (!test_bit(card_index, devices_used))
 375                         break;
 376
 377         if (card_index >= SNDRV_CARDS) {
 378                 mutex_unlock(&devices_mutex);
 379                 return -ENOENT;
 380         }
 381
 382         err = snd_card_new(&interface->dev, index[card_index], id[card_index],
 383                         THIS_MODULE, sizeof(*bcd2k), &card);
 384         if (err < 0) {
 385                 mutex_unlock(&devices_mutex);
 386                 return err;
 387         }
 388
 389         bcd2k = card->private_data;
 390         bcd2k->dev = interface_to_usbdev(interface);
 391         bcd2k->card = card;
 392         bcd2k->card_index = card_index;
 393         bcd2k->intf = interface;
 394
 395         snd_card_set_dev(card, &interface->dev);
 396
 397         strncpy(card->driver, "snd-bcd2000", sizeof(card->driver));
 398         strncpy(card->shortname, "BCD2000", sizeof(card->shortname));
 399         usb_make_path(bcd2k->dev, usb_path, sizeof(usb_path));
 400         snprintf(bcd2k->card->longname, sizeof(bcd2k->card->longname),
 401                     "Behringer BCD2000 at %s",
 402                         usb_path);
 403
 404         err = bcd2000_init_midi(bcd2k);
 405         if (err < 0)
 406                 goto probe_error;
 407
 408         err = snd_card_register(card);
 409         if (err < 0)
 410                 goto probe_error;
 411
 412         usb_set_intfdata(interface, bcd2k);
 413         set_bit(card_index, devices_used);
 414
 415         mutex_unlock(&devices_mutex);
 416         return 0;
 417
 418 probe_error:
 419         dev_info(&bcd2k->dev->dev, PREFIX "error during probing");
 420         bcd2000_free_usb_related_resources(bcd2k, interface);
 421         snd_card_free(card);
 422         mutex_unlock(&devices_mutex);
 423         return err;
 424 }
 425
 426 static void bcd2000_disconnect(struct usb_interface *interface)
 427 {
 428         struct bcd2000 *bcd2k = usb_get_intfdata(interface);
 429
 430         if (!bcd2k)
 431                 return;
 432
 433         mutex_lock(&devices_mutex);
 434
 435         /* make sure that userspace cannot create new requests */
 436         snd_card_disconnect(bcd2k->card);
 437
 438         bcd2000_free_usb_related_resources(bcd2k, interface);
 439
 440         clear_bit(bcd2k->card_index, devices_used);
 441
 442         snd_card_free_when_closed(bcd2k->card);
 443
 444         mutex_unlock(&devices_mutex);
 445 }
 446
 447 static struct usb_driver bcd2000_driver = {
 448         .name =         "snd-bcd2000",
 449         .probe =        bcd2000_probe,
 450         .disconnect =   bcd2000_disconnect,
 451         .id_table =     id_table,
 452 };
 453
 454 module_usb_driver(bcd2000_driver);
 455
 456 MODULE_DEVICE_TABLE(usb, id_table);
 457 MODULE_AUTHOR("Mario Kicherer, dev@kicherer.org");
 458 MODULE_DESCRIPTION("Behringer BCD2000 driver");
 459 MODULE_LICENSE("GPL");