drivers/usb/gadget/function/f

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This source file includes following definitions.
func_to_midi
midi_alloc_ep_req
f_midi_read_data
f_midi_handle_out_data
f_midi_complete
f_midi_drop_out_substreams
f_midi_start_ep
f_midi_set_alt
f_midi_disable
f_midi_snd_free
f_midi_transmit_byte
f_midi_do_transmit
f_midi_transmit
f_midi_in_tasklet
f_midi_in_open
f_midi_in_close
f_midi_in_trigger
f_midi_out_open
f_midi_out_close
f_midi_out_trigger
f_midi_unregister_card
f_midi_register_card
f_midi_bind
to_f_midi_opts
midi_attr_release
f_midi_opts_id_show
f_midi_opts_id_store
f_midi_free_inst
f_midi_alloc_inst
f_midi_free
f_midi_rmidi_free
f_midi_unbind
f_midi_alloc
   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * f_midi.c -- USB MIDI class function driver
   4  *
   5  * Copyright (C) 2006 Thumtronics Pty Ltd.
   6  * Developed for Thumtronics by Grey Innovation
   7  * Ben Williamson <ben.williamson@greyinnovation.com>
   8  *
   9  * Rewritten for the composite framework
  10  *   Copyright (C) 2011 Daniel Mack <zonque@gmail.com>
  11  *
  12  * Based on drivers/usb/gadget/f_audio.c,
  13  *   Copyright (C) 2008 Bryan Wu <cooloney@kernel.org>
  14  *   Copyright (C) 2008 Analog Devices, Inc
  15  *
  16  * and drivers/usb/gadget/midi.c,
  17  *   Copyright (C) 2006 Thumtronics Pty Ltd.
  18  *   Ben Williamson <ben.williamson@greyinnovation.com>
  19  */
  20 
  21 #include <linux/kernel.h>
  22 #include <linux/module.h>
  23 #include <linux/slab.h>
  24 #include <linux/device.h>
  25 #include <linux/kfifo.h>
  26 #include <linux/spinlock.h>
  27 
  28 #include <sound/core.h>
  29 #include <sound/initval.h>
  30 #include <sound/rawmidi.h>
  31 
  32 #include <linux/usb/ch9.h>
  33 #include <linux/usb/gadget.h>
  34 #include <linux/usb/audio.h>
  35 #include <linux/usb/midi.h>
  36 
  37 #include "u_f.h"
  38 #include "u_midi.h"
  39 
  40 MODULE_AUTHOR("Ben Williamson");
  41 MODULE_LICENSE("GPL v2");
  42 
  43 static const char f_midi_shortname[] = "f_midi";
  44 static const char f_midi_longname[] = "MIDI Gadget";
  45 
  46 /*
  47  * We can only handle 16 cables on one single endpoint, as cable numbers are
  48  * stored in 4-bit fields. And as the interface currently only holds one
  49  * single endpoint, this is the maximum number of ports we can allow.
  50  */
  51 #define MAX_PORTS 16
  52 
  53 /* MIDI message states */
  54 enum {
  55         STATE_INITIAL = 0,      /* pseudo state */
  56         STATE_1PARAM,
  57         STATE_2PARAM_1,
  58         STATE_2PARAM_2,
  59         STATE_SYSEX_0,
  60         STATE_SYSEX_1,
  61         STATE_SYSEX_2,
  62         STATE_REAL_TIME,
  63         STATE_FINISHED,         /* pseudo state */
  64 };
  65 
  66 /*
  67  * This is a gadget, and the IN/OUT naming is from the host's perspective.
  68  * USB -> OUT endpoint -> rawmidi
  69  * USB <- IN endpoint  <- rawmidi
  70  */
  71 struct gmidi_in_port {
  72         struct snd_rawmidi_substream *substream;
  73         int active;
  74         uint8_t cable;
  75         uint8_t state;
  76         uint8_t data[2];
  77 };
  78 
  79 struct f_midi {
  80         struct usb_function     func;
  81         struct usb_gadget       *gadget;
  82         struct usb_ep           *in_ep, *out_ep;
  83         struct snd_card         *card;
  84         struct snd_rawmidi      *rmidi;
  85         u8                      ms_id;
  86 
  87         struct snd_rawmidi_substream *out_substream[MAX_PORTS];
  88 
  89         unsigned long           out_triggered;
  90         struct tasklet_struct   tasklet;
  91         unsigned int in_ports;
  92         unsigned int out_ports;
  93         int index;
  94         char *id;
  95         unsigned int buflen, qlen;
  96         /* This fifo is used as a buffer ring for pre-allocated IN usb_requests */
  97         DECLARE_KFIFO_PTR(in_req_fifo, struct usb_request *);
  98         spinlock_t transmit_lock;
  99         unsigned int in_last_port;
 100         unsigned char free_ref;
 101 
 102         struct gmidi_in_port    in_ports_array[/* in_ports */];
 103 };
 104 
 105 static inline struct f_midi *func_to_midi(struct usb_function *f)
 106 {
 107         return container_of(f, struct f_midi, func);
 108 }
 109 
 110 static void f_midi_transmit(struct f_midi *midi);
 111 static void f_midi_rmidi_free(struct snd_rawmidi *rmidi);
 112 static void f_midi_free_inst(struct usb_function_instance *f);
 113 
 114 DECLARE_UAC_AC_HEADER_DESCRIPTOR(1);
 115 DECLARE_USB_MIDI_OUT_JACK_DESCRIPTOR(1);
 116 DECLARE_USB_MS_ENDPOINT_DESCRIPTOR(16);
 117 
 118 /* B.3.1  Standard AC Interface Descriptor */
 119 static struct usb_interface_descriptor ac_interface_desc = {
 120         .bLength =              USB_DT_INTERFACE_SIZE,
 121         .bDescriptorType =      USB_DT_INTERFACE,
 122         /* .bInterfaceNumber =  DYNAMIC */
 123         /* .bNumEndpoints =     DYNAMIC */
 124         .bInterfaceClass =      USB_CLASS_AUDIO,
 125         .bInterfaceSubClass =   USB_SUBCLASS_AUDIOCONTROL,
 126         /* .iInterface =        DYNAMIC */
 127 };
 128 
 129 /* B.3.2  Class-Specific AC Interface Descriptor */
 130 static struct uac1_ac_header_descriptor_1 ac_header_desc = {
 131         .bLength =              UAC_DT_AC_HEADER_SIZE(1),
 132         .bDescriptorType =      USB_DT_CS_INTERFACE,
 133         .bDescriptorSubtype =   USB_MS_HEADER,
 134         .bcdADC =               cpu_to_le16(0x0100),
 135         .wTotalLength =         cpu_to_le16(UAC_DT_AC_HEADER_SIZE(1)),
 136         .bInCollection =        1,
 137         /* .baInterfaceNr =     DYNAMIC */
 138 };
 139 
 140 /* B.4.1  Standard MS Interface Descriptor */
 141 static struct usb_interface_descriptor ms_interface_desc = {
 142         .bLength =              USB_DT_INTERFACE_SIZE,
 143         .bDescriptorType =      USB_DT_INTERFACE,
 144         /* .bInterfaceNumber =  DYNAMIC */
 145         .bNumEndpoints =        2,
 146         .bInterfaceClass =      USB_CLASS_AUDIO,
 147         .bInterfaceSubClass =   USB_SUBCLASS_MIDISTREAMING,
 148         /* .iInterface =        DYNAMIC */
 149 };
 150 
 151 /* B.4.2  Class-Specific MS Interface Descriptor */
 152 static struct usb_ms_header_descriptor ms_header_desc = {
 153         .bLength =              USB_DT_MS_HEADER_SIZE,
 154         .bDescriptorType =      USB_DT_CS_INTERFACE,
 155         .bDescriptorSubtype =   USB_MS_HEADER,
 156         .bcdMSC =               cpu_to_le16(0x0100),
 157         /* .wTotalLength =      DYNAMIC */
 158 };
 159 
 160 /* B.5.1  Standard Bulk OUT Endpoint Descriptor */
 161 static struct usb_endpoint_descriptor bulk_out_desc = {
 162         .bLength =              USB_DT_ENDPOINT_AUDIO_SIZE,
 163         .bDescriptorType =      USB_DT_ENDPOINT,
 164         .bEndpointAddress =     USB_DIR_OUT,
 165         .bmAttributes =         USB_ENDPOINT_XFER_BULK,
 166 };
 167 
 168 static struct usb_ss_ep_comp_descriptor bulk_out_ss_comp_desc = {
 169         .bLength                = sizeof(bulk_out_ss_comp_desc),
 170         .bDescriptorType        = USB_DT_SS_ENDPOINT_COMP,
 171         /* .bMaxBurst           = 0, */
 172         /* .bmAttributes        = 0, */
 173 };
 174 
 175 /* B.5.2  Class-specific MS Bulk OUT Endpoint Descriptor */
 176 static struct usb_ms_endpoint_descriptor_16 ms_out_desc = {
 177         /* .bLength =           DYNAMIC */
 178         .bDescriptorType =      USB_DT_CS_ENDPOINT,
 179         .bDescriptorSubtype =   USB_MS_GENERAL,
 180         /* .bNumEmbMIDIJack =   DYNAMIC */
 181         /* .baAssocJackID =     DYNAMIC */
 182 };
 183 
 184 /* B.6.1  Standard Bulk IN Endpoint Descriptor */
 185 static struct usb_endpoint_descriptor bulk_in_desc = {
 186         .bLength =              USB_DT_ENDPOINT_AUDIO_SIZE,
 187         .bDescriptorType =      USB_DT_ENDPOINT,
 188         .bEndpointAddress =     USB_DIR_IN,
 189         .bmAttributes =         USB_ENDPOINT_XFER_BULK,
 190 };
 191 
 192 static struct usb_ss_ep_comp_descriptor bulk_in_ss_comp_desc = {
 193         .bLength                = sizeof(bulk_in_ss_comp_desc),
 194         .bDescriptorType        = USB_DT_SS_ENDPOINT_COMP,
 195         /* .bMaxBurst           = 0, */
 196         /* .bmAttributes        = 0, */
 197 };
 198 
 199 /* B.6.2  Class-specific MS Bulk IN Endpoint Descriptor */
 200 static struct usb_ms_endpoint_descriptor_16 ms_in_desc = {
 201         /* .bLength =           DYNAMIC */
 202         .bDescriptorType =      USB_DT_CS_ENDPOINT,
 203         .bDescriptorSubtype =   USB_MS_GENERAL,
 204         /* .bNumEmbMIDIJack =   DYNAMIC */
 205         /* .baAssocJackID =     DYNAMIC */
 206 };
 207 
 208 /* string IDs are assigned dynamically */
 209 
 210 #define STRING_FUNC_IDX                 0
 211 
 212 static struct usb_string midi_string_defs[] = {
 213         [STRING_FUNC_IDX].s = "MIDI function",
 214         {  } /* end of list */
 215 };
 216 
 217 static struct usb_gadget_strings midi_stringtab = {
 218         .language       = 0x0409,       /* en-us */
 219         .strings        = midi_string_defs,
 220 };
 221 
 222 static struct usb_gadget_strings *midi_strings[] = {
 223         &midi_stringtab,
 224         NULL,
 225 };
 226 
 227 static inline struct usb_request *midi_alloc_ep_req(struct usb_ep *ep,
 228                                                     unsigned length)
 229 {
 230         return alloc_ep_req(ep, length);
 231 }
 232 
 233 static const uint8_t f_midi_cin_length[] = {
 234         0, 0, 2, 3, 3, 1, 2, 3, 3, 3, 3, 3, 2, 2, 3, 1
 235 };
 236 
 237 /*
 238  * Receives a chunk of MIDI data.
 239  */
 240 static void f_midi_read_data(struct usb_ep *ep, int cable,
 241                              uint8_t *data, int length)
 242 {
 243         struct f_midi *midi = ep->driver_data;
 244         struct snd_rawmidi_substream *substream = midi->out_substream[cable];
 245 
 246         if (!substream)
 247                 /* Nobody is listening - throw it on the floor. */
 248                 return;
 249 
 250         if (!test_bit(cable, &midi->out_triggered))
 251                 return;
 252 
 253         snd_rawmidi_receive(substream, data, length);
 254 }
 255 
 256 static void f_midi_handle_out_data(struct usb_ep *ep, struct usb_request *req)
 257 {
 258         unsigned int i;
 259         u8 *buf = req->buf;
 260 
 261         for (i = 0; i + 3 < req->actual; i += 4)
 262                 if (buf[i] != 0) {
 263                         int cable = buf[i] >> 4;
 264                         int length = f_midi_cin_length[buf[i] & 0x0f];
 265                         f_midi_read_data(ep, cable, &buf[i + 1], length);
 266                 }
 267 }
 268 
 269 static void
 270 f_midi_complete(struct usb_ep *ep, struct usb_request *req)
 271 {
 272         struct f_midi *midi = ep->driver_data;
 273         struct usb_composite_dev *cdev = midi->func.config->cdev;
 274         int status = req->status;
 275 
 276         switch (status) {
 277         case 0:                  /* normal completion */
 278                 if (ep == midi->out_ep) {
 279                         /* We received stuff. req is queued again, below */
 280                         f_midi_handle_out_data(ep, req);
 281                 } else if (ep == midi->in_ep) {
 282                         /* Our transmit completed. See if there's more to go.
 283                          * f_midi_transmit eats req, don't queue it again. */
 284                         req->length = 0;
 285                         f_midi_transmit(midi);
 286                         return;
 287                 }
 288                 break;
 289 
 290         /* this endpoint is normally active while we're configured */
 291         case -ECONNABORTED:     /* hardware forced ep reset */
 292         case -ECONNRESET:       /* request dequeued */
 293         case -ESHUTDOWN:        /* disconnect from host */
 294                 VDBG(cdev, "%s gone (%d), %d/%d\n", ep->name, status,
 295                                 req->actual, req->length);
 296                 if (ep == midi->out_ep) {
 297                         f_midi_handle_out_data(ep, req);
 298                         /* We don't need to free IN requests because it's handled
 299                          * by the midi->in_req_fifo. */
 300                         free_ep_req(ep, req);
 301                 }
 302                 return;
 303 
 304         case -EOVERFLOW:        /* buffer overrun on read means that
 305                                  * we didn't provide a big enough buffer.
 306                                  */
 307         default:
 308                 DBG(cdev, "%s complete --> %d, %d/%d\n", ep->name,
 309                                 status, req->actual, req->length);
 310                 break;
 311         case -EREMOTEIO:        /* short read */
 312                 break;
 313         }
 314 
 315         status = usb_ep_queue(ep, req, GFP_ATOMIC);
 316         if (status) {
 317                 ERROR(cdev, "kill %s:  resubmit %d bytes --> %d\n",
 318                                 ep->name, req->length, status);
 319                 usb_ep_set_halt(ep);
 320                 /* FIXME recover later ... somehow */
 321         }
 322 }
 323 
 324 static void f_midi_drop_out_substreams(struct f_midi *midi)
 325 {
 326         unsigned int i;
 327 
 328         for (i = 0; i < midi->in_ports; i++) {
 329                 struct gmidi_in_port *port = midi->in_ports_array + i;
 330                 struct snd_rawmidi_substream *substream = port->substream;
 331 
 332                 if (port->active && substream)
 333                         snd_rawmidi_drop_output(substream);
 334         }
 335 }
 336 
 337 static int f_midi_start_ep(struct f_midi *midi,
 338                            struct usb_function *f,
 339                            struct usb_ep *ep)
 340 {
 341         int err;
 342         struct usb_composite_dev *cdev = f->config->cdev;
 343 
 344         usb_ep_disable(ep);
 345 
 346         err = config_ep_by_speed(midi->gadget, f, ep);
 347         if (err) {
 348                 ERROR(cdev, "can't configure %s: %d\n", ep->name, err);
 349                 return err;
 350         }
 351 
 352         err = usb_ep_enable(ep);
 353         if (err) {
 354                 ERROR(cdev, "can't start %s: %d\n", ep->name, err);
 355                 return err;
 356         }
 357 
 358         ep->driver_data = midi;
 359 
 360         return 0;
 361 }
 362 
 363 static int f_midi_set_alt(struct usb_function *f, unsigned intf, unsigned alt)
 364 {
 365         struct f_midi *midi = func_to_midi(f);
 366         unsigned i;
 367         int err;
 368 
 369         /* we only set alt for MIDIStreaming interface */
 370         if (intf != midi->ms_id)
 371                 return 0;
 372 
 373         err = f_midi_start_ep(midi, f, midi->in_ep);
 374         if (err)
 375                 return err;
 376 
 377         err = f_midi_start_ep(midi, f, midi->out_ep);
 378         if (err)
 379                 return err;
 380 
 381         /* pre-allocate write usb requests to use on f_midi_transmit. */
 382         while (kfifo_avail(&midi->in_req_fifo)) {
 383                 struct usb_request *req =
 384                         midi_alloc_ep_req(midi->in_ep, midi->buflen);
 385 
 386                 if (req == NULL)
 387                         return -ENOMEM;
 388 
 389                 req->length = 0;
 390                 req->complete = f_midi_complete;
 391 
 392                 kfifo_put(&midi->in_req_fifo, req);
 393         }
 394 
 395         /* allocate a bunch of read buffers and queue them all at once. */
 396         for (i = 0; i < midi->qlen && err == 0; i++) {
 397                 struct usb_request *req =
 398                         midi_alloc_ep_req(midi->out_ep, midi->buflen);
 399 
 400                 if (req == NULL)
 401                         return -ENOMEM;
 402 
 403                 req->complete = f_midi_complete;
 404                 err = usb_ep_queue(midi->out_ep, req, GFP_ATOMIC);
 405                 if (err) {
 406                         ERROR(midi, "%s: couldn't enqueue request: %d\n",
 407                                     midi->out_ep->name, err);
 408                         if (req->buf != NULL)
 409                                 free_ep_req(midi->out_ep, req);
 410                         return err;
 411                 }
 412         }
 413 
 414         return 0;
 415 }
 416 
 417 static void f_midi_disable(struct usb_function *f)
 418 {
 419         struct f_midi *midi = func_to_midi(f);
 420         struct usb_composite_dev *cdev = f->config->cdev;
 421         struct usb_request *req = NULL;
 422 
 423         DBG(cdev, "disable\n");
 424 
 425         /*
 426          * just disable endpoints, forcing completion of pending i/o.
 427          * all our completion handlers free their requests in this case.
 428          */
 429         usb_ep_disable(midi->in_ep);
 430         usb_ep_disable(midi->out_ep);
 431 
 432         /* release IN requests */
 433         while (kfifo_get(&midi->in_req_fifo, &req))
 434                 free_ep_req(midi->in_ep, req);
 435 
 436         f_midi_drop_out_substreams(midi);
 437 }
 438 
 439 static int f_midi_snd_free(struct snd_device *device)
 440 {
 441         return 0;
 442 }
 443 
 444 /*
 445  * Converts MIDI commands to USB MIDI packets.
 446  */
 447 static void f_midi_transmit_byte(struct usb_request *req,
 448                                  struct gmidi_in_port *port, uint8_t b)
 449 {
 450         uint8_t p[4] = { port->cable << 4, 0, 0, 0 };
 451         uint8_t next_state = STATE_INITIAL;
 452 
 453         switch (b) {
 454         case 0xf8 ... 0xff:
 455                 /* System Real-Time Messages */
 456                 p[0] |= 0x0f;
 457                 p[1] = b;
 458                 next_state = port->state;
 459                 port->state = STATE_REAL_TIME;
 460                 break;
 461 
 462         case 0xf7:
 463                 /* End of SysEx */
 464                 switch (port->state) {
 465                 case STATE_SYSEX_0:
 466                         p[0] |= 0x05;
 467                         p[1] = 0xf7;
 468                         next_state = STATE_FINISHED;
 469                         break;
 470                 case STATE_SYSEX_1:
 471                         p[0] |= 0x06;
 472                         p[1] = port->data[0];
 473                         p[2] = 0xf7;
 474                         next_state = STATE_FINISHED;
 475                         break;
 476                 case STATE_SYSEX_2:
 477                         p[0] |= 0x07;
 478                         p[1] = port->data[0];
 479                         p[2] = port->data[1];
 480                         p[3] = 0xf7;
 481                         next_state = STATE_FINISHED;
 482                         break;
 483                 default:
 484                         /* Ignore byte */
 485                         next_state = port->state;
 486                         port->state = STATE_INITIAL;
 487                 }
 488                 break;
 489 
 490         case 0xf0 ... 0xf6:
 491                 /* System Common Messages */
 492                 port->data[0] = port->data[1] = 0;
 493                 port->state = STATE_INITIAL;
 494                 switch (b) {
 495                 case 0xf0:
 496                         port->data[0] = b;
 497                         port->data[1] = 0;
 498                         next_state = STATE_SYSEX_1;
 499                         break;
 500                 case 0xf1:
 501                 case 0xf3:
 502                         port->data[0] = b;
 503                         next_state = STATE_1PARAM;
 504                         break;
 505                 case 0xf2:
 506                         port->data[0] = b;
 507                         next_state = STATE_2PARAM_1;
 508                         break;
 509                 case 0xf4:
 510                 case 0xf5:
 511                         next_state = STATE_INITIAL;
 512                         break;
 513                 case 0xf6:
 514                         p[0] |= 0x05;
 515                         p[1] = 0xf6;
 516                         next_state = STATE_FINISHED;
 517                         break;
 518                 }
 519                 break;
 520 
 521         case 0x80 ... 0xef:
 522                 /*
 523                  * Channel Voice Messages, Channel Mode Messages
 524                  * and Control Change Messages.
 525                  */
 526                 port->data[0] = b;
 527                 port->data[1] = 0;
 528                 port->state = STATE_INITIAL;
 529                 if (b >= 0xc0 && b <= 0xdf)
 530                         next_state = STATE_1PARAM;
 531                 else
 532                         next_state = STATE_2PARAM_1;
 533                 break;
 534 
 535         case 0x00 ... 0x7f:
 536                 /* Message parameters */
 537                 switch (port->state) {
 538                 case STATE_1PARAM:
 539                         if (port->data[0] < 0xf0)
 540                                 p[0] |= port->data[0] >> 4;
 541                         else
 542                                 p[0] |= 0x02;
 543 
 544                         p[1] = port->data[0];
 545                         p[2] = b;
 546                         /* This is to allow Running State Messages */
 547                         next_state = STATE_1PARAM;
 548                         break;
 549                 case STATE_2PARAM_1:
 550                         port->data[1] = b;
 551                         next_state = STATE_2PARAM_2;
 552                         break;
 553                 case STATE_2PARAM_2:
 554                         if (port->data[0] < 0xf0)
 555                                 p[0] |= port->data[0] >> 4;
 556                         else
 557                                 p[0] |= 0x03;
 558 
 559                         p[1] = port->data[0];
 560                         p[2] = port->data[1];
 561                         p[3] = b;
 562                         /* This is to allow Running State Messages */
 563                         next_state = STATE_2PARAM_1;
 564                         break;
 565                 case STATE_SYSEX_0:
 566                         port->data[0] = b;
 567                         next_state = STATE_SYSEX_1;
 568                         break;
 569                 case STATE_SYSEX_1:
 570                         port->data[1] = b;
 571                         next_state = STATE_SYSEX_2;
 572                         break;
 573                 case STATE_SYSEX_2:
 574                         p[0] |= 0x04;
 575                         p[1] = port->data[0];
 576                         p[2] = port->data[1];
 577                         p[3] = b;
 578                         next_state = STATE_SYSEX_0;
 579                         break;
 580                 }
 581                 break;
 582         }
 583 
 584         /* States where we have to write into the USB request */
 585         if (next_state == STATE_FINISHED ||
 586             port->state == STATE_SYSEX_2 ||
 587             port->state == STATE_1PARAM ||
 588             port->state == STATE_2PARAM_2 ||
 589             port->state == STATE_REAL_TIME) {
 590 
 591                 unsigned int length = req->length;
 592                 u8 *buf = (u8 *)req->buf + length;
 593 
 594                 memcpy(buf, p, sizeof(p));
 595                 req->length = length + sizeof(p);
 596 
 597                 if (next_state == STATE_FINISHED) {
 598                         next_state = STATE_INITIAL;
 599                         port->data[0] = port->data[1] = 0;
 600                 }
 601         }
 602 
 603         port->state = next_state;
 604 }
 605 
 606 static int f_midi_do_transmit(struct f_midi *midi, struct usb_ep *ep)
 607 {
 608         struct usb_request *req = NULL;
 609         unsigned int len, i;
 610         bool active = false;
 611         int err;
 612 
 613         /*
 614          * We peek the request in order to reuse it if it fails to enqueue on
 615          * its endpoint
 616          */
 617         len = kfifo_peek(&midi->in_req_fifo, &req);
 618         if (len != 1) {
 619                 ERROR(midi, "%s: Couldn't get usb request\n", __func__);
 620                 return -1;
 621         }
 622 
 623         /*
 624          * If buffer overrun, then we ignore this transmission.
 625          * IMPORTANT: This will cause the user-space rawmidi device to block
 626          * until a) usb requests have been completed or b) snd_rawmidi_write()
 627          * times out.
 628          */
 629         if (req->length > 0)
 630                 return 0;
 631 
 632         for (i = midi->in_last_port; i < midi->in_ports; ++i) {
 633                 struct gmidi_in_port *port = midi->in_ports_array + i;
 634                 struct snd_rawmidi_substream *substream = port->substream;
 635 
 636                 if (!port->active || !substream)
 637                         continue;
 638 
 639                 while (req->length + 3 < midi->buflen) {
 640                         uint8_t b;
 641 
 642                         if (snd_rawmidi_transmit(substream, &b, 1) != 1) {
 643                                 port->active = 0;
 644                                 break;
 645                         }
 646                         f_midi_transmit_byte(req, port, b);
 647                 }
 648 
 649                 active = !!port->active;
 650                 if (active)
 651                         break;
 652         }
 653         midi->in_last_port = active ? i : 0;
 654 
 655         if (req->length <= 0)
 656                 goto done;
 657 
 658         err = usb_ep_queue(ep, req, GFP_ATOMIC);
 659         if (err < 0) {
 660                 ERROR(midi, "%s failed to queue req: %d\n",
 661                       midi->in_ep->name, err);
 662                 req->length = 0; /* Re-use request next time. */
 663         } else {
 664                 /* Upon success, put request at the back of the queue. */
 665                 kfifo_skip(&midi->in_req_fifo);
 666                 kfifo_put(&midi->in_req_fifo, req);
 667         }
 668 
 669 done:
 670         return active;
 671 }
 672 
 673 static void f_midi_transmit(struct f_midi *midi)
 674 {
 675         struct usb_ep *ep = midi->in_ep;
 676         int ret;
 677         unsigned long flags;
 678 
 679         /* We only care about USB requests if IN endpoint is enabled */
 680         if (!ep || !ep->enabled)
 681                 goto drop_out;
 682 
 683         spin_lock_irqsave(&midi->transmit_lock, flags);
 684 
 685         do {
 686                 ret = f_midi_do_transmit(midi, ep);
 687                 if (ret < 0) {
 688                         spin_unlock_irqrestore(&midi->transmit_lock, flags);
 689                         goto drop_out;
 690                 }
 691         } while (ret);
 692 
 693         spin_unlock_irqrestore(&midi->transmit_lock, flags);
 694 
 695         return;
 696 
 697 drop_out:
 698         f_midi_drop_out_substreams(midi);
 699 }
 700 
 701 static void f_midi_in_tasklet(unsigned long data)
 702 {
 703         struct f_midi *midi = (struct f_midi *) data;
 704         f_midi_transmit(midi);
 705 }
 706 
 707 static int f_midi_in_open(struct snd_rawmidi_substream *substream)
 708 {
 709         struct f_midi *midi = substream->rmidi->private_data;
 710         struct gmidi_in_port *port;
 711 
 712         if (substream->number >= midi->in_ports)
 713                 return -EINVAL;
 714 
 715         VDBG(midi, "%s()\n", __func__);
 716         port = midi->in_ports_array + substream->number;
 717         port->substream = substream;
 718         port->state = STATE_INITIAL;
 719         return 0;
 720 }
 721 
 722 static int f_midi_in_close(struct snd_rawmidi_substream *substream)
 723 {
 724         struct f_midi *midi = substream->rmidi->private_data;
 725 
 726         VDBG(midi, "%s()\n", __func__);
 727         return 0;
 728 }
 729 
 730 static void f_midi_in_trigger(struct snd_rawmidi_substream *substream, int up)
 731 {
 732         struct f_midi *midi = substream->rmidi->private_data;
 733 
 734         if (substream->number >= midi->in_ports)
 735                 return;
 736 
 737         VDBG(midi, "%s() %d\n", __func__, up);
 738         midi->in_ports_array[substream->number].active = up;
 739         if (up)
 740                 tasklet_hi_schedule(&midi->tasklet);
 741 }
 742 
 743 static int f_midi_out_open(struct snd_rawmidi_substream *substream)
 744 {
 745         struct f_midi *midi = substream->rmidi->private_data;
 746 
 747         if (substream->number >= MAX_PORTS)
 748                 return -EINVAL;
 749 
 750         VDBG(midi, "%s()\n", __func__);
 751         midi->out_substream[substream->number] = substream;
 752         return 0;
 753 }
 754 
 755 static int f_midi_out_close(struct snd_rawmidi_substream *substream)
 756 {
 757         struct f_midi *midi = substream->rmidi->private_data;
 758 
 759         VDBG(midi, "%s()\n", __func__);
 760         return 0;
 761 }
 762 
 763 static void f_midi_out_trigger(struct snd_rawmidi_substream *substream, int up)
 764 {
 765         struct f_midi *midi = substream->rmidi->private_data;
 766 
 767         VDBG(midi, "%s()\n", __func__);
 768 
 769         if (up)
 770                 set_bit(substream->number, &midi->out_triggered);
 771         else
 772                 clear_bit(substream->number, &midi->out_triggered);
 773 }
 774 
 775 static const struct snd_rawmidi_ops gmidi_in_ops = {
 776         .open = f_midi_in_open,
 777         .close = f_midi_in_close,
 778         .trigger = f_midi_in_trigger,
 779 };
 780 
 781 static const struct snd_rawmidi_ops gmidi_out_ops = {
 782         .open = f_midi_out_open,
 783         .close = f_midi_out_close,
 784         .trigger = f_midi_out_trigger
 785 };
 786 
 787 static inline void f_midi_unregister_card(struct f_midi *midi)
 788 {
 789         if (midi->card) {
 790                 snd_card_free(midi->card);
 791                 midi->card = NULL;
 792         }
 793 }
 794 
 795 /* register as a sound "card" */
 796 static int f_midi_register_card(struct f_midi *midi)
 797 {
 798         struct snd_card *card;
 799         struct snd_rawmidi *rmidi;
 800         int err;
 801         static struct snd_device_ops ops = {
 802                 .dev_free = f_midi_snd_free,
 803         };
 804 
 805         err = snd_card_new(&midi->gadget->dev, midi->index, midi->id,
 806                            THIS_MODULE, 0, &card);
 807         if (err < 0) {
 808                 ERROR(midi, "snd_card_new() failed\n");
 809                 goto fail;
 810         }
 811         midi->card = card;
 812 
 813         err = snd_device_new(card, SNDRV_DEV_LOWLEVEL, midi, &ops);
 814         if (err < 0) {
 815                 ERROR(midi, "snd_device_new() failed: error %d\n", err);
 816                 goto fail;
 817         }
 818 
 819         strcpy(card->driver, f_midi_longname);
 820         strcpy(card->longname, f_midi_longname);
 821         strcpy(card->shortname, f_midi_shortname);
 822 
 823         /* Set up rawmidi */
 824         snd_component_add(card, "MIDI");
 825         err = snd_rawmidi_new(card, card->longname, 0,
 826                               midi->out_ports, midi->in_ports, &rmidi);
 827         if (err < 0) {
 828                 ERROR(midi, "snd_rawmidi_new() failed: error %d\n", err);
 829                 goto fail;
 830         }
 831         midi->rmidi = rmidi;
 832         midi->in_last_port = 0;
 833         strcpy(rmidi->name, card->shortname);
 834         rmidi->info_flags = SNDRV_RAWMIDI_INFO_OUTPUT |
 835                             SNDRV_RAWMIDI_INFO_INPUT |
 836                             SNDRV_RAWMIDI_INFO_DUPLEX;
 837         rmidi->private_data = midi;
 838         rmidi->private_free = f_midi_rmidi_free;
 839         midi->free_ref++;
 840 
 841         /*
 842          * Yes, rawmidi OUTPUT = USB IN, and rawmidi INPUT = USB OUT.
 843          * It's an upside-down world being a gadget.
 844          */
 845         snd_rawmidi_set_ops(rmidi, SNDRV_RAWMIDI_STREAM_OUTPUT, &gmidi_in_ops);
 846         snd_rawmidi_set_ops(rmidi, SNDRV_RAWMIDI_STREAM_INPUT, &gmidi_out_ops);
 847 
 848         /* register it - we're ready to go */
 849         err = snd_card_register(card);
 850         if (err < 0) {
 851                 ERROR(midi, "snd_card_register() failed\n");
 852                 goto fail;
 853         }
 854 
 855         VDBG(midi, "%s() finished ok\n", __func__);
 856         return 0;
 857 
 858 fail:
 859         f_midi_unregister_card(midi);
 860         return err;
 861 }
 862 
 863 /* MIDI function driver setup/binding */
 864 
 865 static int f_midi_bind(struct usb_configuration *c, struct usb_function *f)
 866 {
 867         struct usb_descriptor_header **midi_function;
 868         struct usb_midi_in_jack_descriptor jack_in_ext_desc[MAX_PORTS];
 869         struct usb_midi_in_jack_descriptor jack_in_emb_desc[MAX_PORTS];
 870         struct usb_midi_out_jack_descriptor_1 jack_out_ext_desc[MAX_PORTS];
 871         struct usb_midi_out_jack_descriptor_1 jack_out_emb_desc[MAX_PORTS];
 872         struct usb_composite_dev *cdev = c->cdev;
 873         struct f_midi *midi = func_to_midi(f);
 874         struct usb_string *us;
 875         int status, n, jack = 1, i = 0, endpoint_descriptor_index = 0;
 876 
 877         midi->gadget = cdev->gadget;
 878         tasklet_init(&midi->tasklet, f_midi_in_tasklet, (unsigned long) midi);
 879         status = f_midi_register_card(midi);
 880         if (status < 0)
 881                 goto fail_register;
 882 
 883         /* maybe allocate device-global string ID */
 884         us = usb_gstrings_attach(c->cdev, midi_strings,
 885                                  ARRAY_SIZE(midi_string_defs));
 886         if (IS_ERR(us)) {
 887                 status = PTR_ERR(us);
 888                 goto fail;
 889         }
 890         ac_interface_desc.iInterface = us[STRING_FUNC_IDX].id;
 891 
 892         /* We have two interfaces, AudioControl and MIDIStreaming */
 893         status = usb_interface_id(c, f);
 894         if (status < 0)
 895                 goto fail;
 896         ac_interface_desc.bInterfaceNumber = status;
 897 
 898         status = usb_interface_id(c, f);
 899         if (status < 0)
 900                 goto fail;
 901         ms_interface_desc.bInterfaceNumber = status;
 902         ac_header_desc.baInterfaceNr[0] = status;
 903         midi->ms_id = status;
 904 
 905         status = -ENODEV;
 906 
 907         /* allocate instance-specific endpoints */
 908         midi->in_ep = usb_ep_autoconfig(cdev->gadget, &bulk_in_desc);
 909         if (!midi->in_ep)
 910                 goto fail;
 911 
 912         midi->out_ep = usb_ep_autoconfig(cdev->gadget, &bulk_out_desc);
 913         if (!midi->out_ep)
 914                 goto fail;
 915 
 916         /* allocate temporary function list */
 917         midi_function = kcalloc((MAX_PORTS * 4) + 11, sizeof(*midi_function),
 918                                 GFP_KERNEL);
 919         if (!midi_function) {
 920                 status = -ENOMEM;
 921                 goto fail;
 922         }
 923 
 924         /*
 925          * construct the function's descriptor set. As the number of
 926          * input and output MIDI ports is configurable, we have to do
 927          * it that way.
 928          */
 929 
 930         /* add the headers - these are always the same */
 931         midi_function[i++] = (struct usb_descriptor_header *) &ac_interface_desc;
 932         midi_function[i++] = (struct usb_descriptor_header *) &ac_header_desc;
 933         midi_function[i++] = (struct usb_descriptor_header *) &ms_interface_desc;
 934 
 935         /* calculate the header's wTotalLength */
 936         n = USB_DT_MS_HEADER_SIZE
 937                 + (midi->in_ports + midi->out_ports) *
 938                         (USB_DT_MIDI_IN_SIZE + USB_DT_MIDI_OUT_SIZE(1));
 939         ms_header_desc.wTotalLength = cpu_to_le16(n);
 940 
 941         midi_function[i++] = (struct usb_descriptor_header *) &ms_header_desc;
 942 
 943         /* configure the external IN jacks, each linked to an embedded OUT jack */
 944         for (n = 0; n < midi->in_ports; n++) {
 945                 struct usb_midi_in_jack_descriptor *in_ext = &jack_in_ext_desc[n];
 946                 struct usb_midi_out_jack_descriptor_1 *out_emb = &jack_out_emb_desc[n];
 947 
 948                 in_ext->bLength                 = USB_DT_MIDI_IN_SIZE;
 949                 in_ext->bDescriptorType         = USB_DT_CS_INTERFACE;
 950                 in_ext->bDescriptorSubtype      = USB_MS_MIDI_IN_JACK;
 951                 in_ext->bJackType               = USB_MS_EXTERNAL;
 952                 in_ext->bJackID                 = jack++;
 953                 in_ext->iJack                   = 0;
 954                 midi_function[i++] = (struct usb_descriptor_header *) in_ext;
 955 
 956                 out_emb->bLength                = USB_DT_MIDI_OUT_SIZE(1);
 957                 out_emb->bDescriptorType        = USB_DT_CS_INTERFACE;
 958                 out_emb->bDescriptorSubtype     = USB_MS_MIDI_OUT_JACK;
 959                 out_emb->bJackType              = USB_MS_EMBEDDED;
 960                 out_emb->bJackID                = jack++;
 961                 out_emb->bNrInputPins           = 1;
 962                 out_emb->pins[0].baSourcePin    = 1;
 963                 out_emb->pins[0].baSourceID     = in_ext->bJackID;
 964                 out_emb->iJack                  = 0;
 965                 midi_function[i++] = (struct usb_descriptor_header *) out_emb;
 966 
 967                 /* link it to the endpoint */
 968                 ms_in_desc.baAssocJackID[n] = out_emb->bJackID;
 969         }
 970 
 971         /* configure the external OUT jacks, each linked to an embedded IN jack */
 972         for (n = 0; n < midi->out_ports; n++) {
 973                 struct usb_midi_in_jack_descriptor *in_emb = &jack_in_emb_desc[n];
 974                 struct usb_midi_out_jack_descriptor_1 *out_ext = &jack_out_ext_desc[n];
 975 
 976                 in_emb->bLength                 = USB_DT_MIDI_IN_SIZE;
 977                 in_emb->bDescriptorType         = USB_DT_CS_INTERFACE;
 978                 in_emb->bDescriptorSubtype      = USB_MS_MIDI_IN_JACK;
 979                 in_emb->bJackType               = USB_MS_EMBEDDED;
 980                 in_emb->bJackID                 = jack++;
 981                 in_emb->iJack                   = 0;
 982                 midi_function[i++] = (struct usb_descriptor_header *) in_emb;
 983 
 984                 out_ext->bLength =              USB_DT_MIDI_OUT_SIZE(1);
 985                 out_ext->bDescriptorType =      USB_DT_CS_INTERFACE;
 986                 out_ext->bDescriptorSubtype =   USB_MS_MIDI_OUT_JACK;
 987                 out_ext->bJackType =            USB_MS_EXTERNAL;
 988                 out_ext->bJackID =              jack++;
 989                 out_ext->bNrInputPins =         1;
 990                 out_ext->iJack =                0;
 991                 out_ext->pins[0].baSourceID =   in_emb->bJackID;
 992                 out_ext->pins[0].baSourcePin =  1;
 993                 midi_function[i++] = (struct usb_descriptor_header *) out_ext;
 994 
 995                 /* link it to the endpoint */
 996                 ms_out_desc.baAssocJackID[n] = in_emb->bJackID;
 997         }
 998 
 999         /* configure the endpoint descriptors ... */
1000         ms_out_desc.bLength = USB_DT_MS_ENDPOINT_SIZE(midi->in_ports);
1001         ms_out_desc.bNumEmbMIDIJack = midi->in_ports;
1002 
1003         ms_in_desc.bLength = USB_DT_MS_ENDPOINT_SIZE(midi->out_ports);
1004         ms_in_desc.bNumEmbMIDIJack = midi->out_ports;
1005 
1006         /* ... and add them to the list */
1007         endpoint_descriptor_index = i;
1008         midi_function[i++] = (struct usb_descriptor_header *) &bulk_out_desc;
1009         midi_function[i++] = (struct usb_descriptor_header *) &ms_out_desc;
1010         midi_function[i++] = (struct usb_descriptor_header *) &bulk_in_desc;
1011         midi_function[i++] = (struct usb_descriptor_header *) &ms_in_desc;
1012         midi_function[i++] = NULL;
1013 
1014         /*
1015          * support all relevant hardware speeds... we expect that when
1016          * hardware is dual speed, all bulk-capable endpoints work at
1017          * both speeds
1018          */
1019         /* copy descriptors, and track endpoint copies */
1020         f->fs_descriptors = usb_copy_descriptors(midi_function);
1021         if (!f->fs_descriptors)
1022                 goto fail_f_midi;
1023 
1024         if (gadget_is_dualspeed(c->cdev->gadget)) {
1025                 bulk_in_desc.wMaxPacketSize = cpu_to_le16(512);
1026                 bulk_out_desc.wMaxPacketSize = cpu_to_le16(512);
1027                 f->hs_descriptors = usb_copy_descriptors(midi_function);
1028                 if (!f->hs_descriptors)
1029                         goto fail_f_midi;
1030         }
1031 
1032         if (gadget_is_superspeed(c->cdev->gadget)) {
1033                 bulk_in_desc.wMaxPacketSize = cpu_to_le16(1024);
1034                 bulk_out_desc.wMaxPacketSize = cpu_to_le16(1024);
1035                 i = endpoint_descriptor_index;
1036                 midi_function[i++] = (struct usb_descriptor_header *)
1037                                      &bulk_out_desc;
1038                 midi_function[i++] = (struct usb_descriptor_header *)
1039                                      &bulk_out_ss_comp_desc;
1040                 midi_function[i++] = (struct usb_descriptor_header *)
1041                                      &ms_out_desc;
1042                 midi_function[i++] = (struct usb_descriptor_header *)
1043                                      &bulk_in_desc;
1044                 midi_function[i++] = (struct usb_descriptor_header *)
1045                                      &bulk_in_ss_comp_desc;
1046                 midi_function[i++] = (struct usb_descriptor_header *)
1047                                      &ms_in_desc;
1048                 f->ss_descriptors = usb_copy_descriptors(midi_function);
1049                 if (!f->ss_descriptors)
1050                         goto fail_f_midi;
1051         }
1052 
1053         kfree(midi_function);
1054 
1055         return 0;
1056 
1057 fail_f_midi:
1058         kfree(midi_function);
1059         usb_free_all_descriptors(f);
1060 fail:
1061         f_midi_unregister_card(midi);
1062 fail_register:
1063         ERROR(cdev, "%s: can't bind, err %d\n", f->name, status);
1064 
1065         return status;
1066 }
1067 
1068 static inline struct f_midi_opts *to_f_midi_opts(struct config_item *item)
1069 {
1070         return container_of(to_config_group(item), struct f_midi_opts,
1071                             func_inst.group);
1072 }
1073 
1074 static void midi_attr_release(struct config_item *item)
1075 {
1076         struct f_midi_opts *opts = to_f_midi_opts(item);
1077 
1078         usb_put_function_instance(&opts->func_inst);
1079 }
1080 
1081 static struct configfs_item_operations midi_item_ops = {
1082         .release        = midi_attr_release,
1083 };
1084 
1085 #define F_MIDI_OPT(name, test_limit, limit)                             \
1086 static ssize_t f_midi_opts_##name##_show(struct config_item *item, char *page) \
1087 {                                                                       \
1088         struct f_midi_opts *opts = to_f_midi_opts(item);                \
1089         int result;                                                     \
1090                                                                         \
1091         mutex_lock(&opts->lock);                                        \
1092         result = sprintf(page, "%d\n", opts->name);                     \
1093         mutex_unlock(&opts->lock);                                      \
1094                                                                         \
1095         return result;                                                  \
1096 }                                                                       \
1097                                                                         \
1098 static ssize_t f_midi_opts_##name##_store(struct config_item *item,     \
1099                                          const char *page, size_t len)  \
1100 {                                                                       \
1101         struct f_midi_opts *opts = to_f_midi_opts(item);                \
1102         int ret;                                                        \
1103         u32 num;                                                        \
1104                                                                         \
1105         mutex_lock(&opts->lock);                                        \
1106         if (opts->refcnt > 1) {                                         \
1107                 ret = -EBUSY;                                           \
1108                 goto end;                                               \
1109         }                                                               \
1110                                                                         \
1111         ret = kstrtou32(page, 0, &num);                                 \
1112         if (ret)                                                        \
1113                 goto end;                                               \
1114                                                                         \
1115         if (test_limit && num > limit) {                                \
1116                 ret = -EINVAL;                                          \
1117                 goto end;                                               \
1118         }                                                               \
1119         opts->name = num;                                               \
1120         ret = len;                                                      \
1121                                                                         \
1122 end:                                                                    \
1123         mutex_unlock(&opts->lock);                                      \
1124         return ret;                                                     \
1125 }                                                                       \
1126                                                                         \
1127 CONFIGFS_ATTR(f_midi_opts_, name);
1128 
1129 F_MIDI_OPT(index, true, SNDRV_CARDS);
1130 F_MIDI_OPT(buflen, false, 0);
1131 F_MIDI_OPT(qlen, false, 0);
1132 F_MIDI_OPT(in_ports, true, MAX_PORTS);
1133 F_MIDI_OPT(out_ports, true, MAX_PORTS);
1134 
1135 static ssize_t f_midi_opts_id_show(struct config_item *item, char *page)
1136 {
1137         struct f_midi_opts *opts = to_f_midi_opts(item);
1138         int result;
1139 
1140         mutex_lock(&opts->lock);
1141         if (opts->id) {
1142                 result = strlcpy(page, opts->id, PAGE_SIZE);
1143         } else {
1144                 page[0] = 0;
1145                 result = 0;
1146         }
1147 
1148         mutex_unlock(&opts->lock);
1149 
1150         return result;
1151 }
1152 
1153 static ssize_t f_midi_opts_id_store(struct config_item *item,
1154                                     const char *page, size_t len)
1155 {
1156         struct f_midi_opts *opts = to_f_midi_opts(item);
1157         int ret;
1158         char *c;
1159 
1160         mutex_lock(&opts->lock);
1161         if (opts->refcnt > 1) {
1162                 ret = -EBUSY;
1163                 goto end;
1164         }
1165 
1166         c = kstrndup(page, len, GFP_KERNEL);
1167         if (!c) {
1168                 ret = -ENOMEM;
1169                 goto end;
1170         }
1171         if (opts->id_allocated)
1172                 kfree(opts->id);
1173         opts->id = c;
1174         opts->id_allocated = true;
1175         ret = len;
1176 end:
1177         mutex_unlock(&opts->lock);
1178         return ret;
1179 }
1180 
1181 CONFIGFS_ATTR(f_midi_opts_, id);
1182 
1183 static struct configfs_attribute *midi_attrs[] = {
1184         &f_midi_opts_attr_index,
1185         &f_midi_opts_attr_buflen,
1186         &f_midi_opts_attr_qlen,
1187         &f_midi_opts_attr_in_ports,
1188         &f_midi_opts_attr_out_ports,
1189         &f_midi_opts_attr_id,
1190         NULL,
1191 };
1192 
1193 static const struct config_item_type midi_func_type = {
1194         .ct_item_ops    = &midi_item_ops,
1195         .ct_attrs       = midi_attrs,
1196         .ct_owner       = THIS_MODULE,
1197 };
1198 
1199 static void f_midi_free_inst(struct usb_function_instance *f)
1200 {
1201         struct f_midi_opts *opts;
1202         bool free = false;
1203 
1204         opts = container_of(f, struct f_midi_opts, func_inst);
1205 
1206         mutex_lock(&opts->lock);
1207         if (!--opts->refcnt) {
1208                 free = true;
1209         }
1210         mutex_unlock(&opts->lock);
1211 
1212         if (free) {
1213                 if (opts->id_allocated)
1214                         kfree(opts->id);
1215                 kfree(opts);
1216         }
1217 }
1218 
1219 static struct usb_function_instance *f_midi_alloc_inst(void)
1220 {
1221         struct f_midi_opts *opts;
1222 
1223         opts = kzalloc(sizeof(*opts), GFP_KERNEL);
1224         if (!opts)
1225                 return ERR_PTR(-ENOMEM);
1226 
1227         mutex_init(&opts->lock);
1228         opts->func_inst.free_func_inst = f_midi_free_inst;
1229         opts->index = SNDRV_DEFAULT_IDX1;
1230         opts->id = SNDRV_DEFAULT_STR1;
1231         opts->buflen = 512;
1232         opts->qlen = 32;
1233         opts->in_ports = 1;
1234         opts->out_ports = 1;
1235         opts->refcnt = 1;
1236 
1237         config_group_init_type_name(&opts->func_inst.group, "",
1238                                     &midi_func_type);
1239 
1240         return &opts->func_inst;
1241 }
1242 
1243 static void f_midi_free(struct usb_function *f)
1244 {
1245         struct f_midi *midi;
1246         struct f_midi_opts *opts;
1247         bool free = false;
1248 
1249         midi = func_to_midi(f);
1250         opts = container_of(f->fi, struct f_midi_opts, func_inst);
1251         mutex_lock(&opts->lock);
1252         if (!--midi->free_ref) {
1253                 kfree(midi->id);
1254                 kfifo_free(&midi->in_req_fifo);
1255                 kfree(midi);
1256                 free = true;
1257         }
1258         mutex_unlock(&opts->lock);
1259 
1260         if (free)
1261                 f_midi_free_inst(&opts->func_inst);
1262 }
1263 
1264 static void f_midi_rmidi_free(struct snd_rawmidi *rmidi)
1265 {
1266         f_midi_free(rmidi->private_data);
1267 }
1268 
1269 static void f_midi_unbind(struct usb_configuration *c, struct usb_function *f)
1270 {
1271         struct usb_composite_dev *cdev = f->config->cdev;
1272         struct f_midi *midi = func_to_midi(f);
1273         struct snd_card *card;
1274 
1275         DBG(cdev, "unbind\n");
1276 
1277         /* just to be sure */
1278         f_midi_disable(f);
1279 
1280         card = midi->card;
1281         midi->card = NULL;
1282         if (card)
1283                 snd_card_free_when_closed(card);
1284 
1285         usb_free_all_descriptors(f);
1286 }
1287 
1288 static struct usb_function *f_midi_alloc(struct usb_function_instance *fi)
1289 {
1290         struct f_midi *midi = NULL;
1291         struct f_midi_opts *opts;
1292         int status, i;
1293 
1294         opts = container_of(fi, struct f_midi_opts, func_inst);
1295 
1296         mutex_lock(&opts->lock);
1297         /* sanity check */
1298         if (opts->in_ports > MAX_PORTS || opts->out_ports > MAX_PORTS) {
1299                 status = -EINVAL;
1300                 goto setup_fail;
1301         }
1302 
1303         /* allocate and initialize one new instance */
1304         midi = kzalloc(struct_size(midi, in_ports_array, opts->in_ports),
1305                        GFP_KERNEL);
1306         if (!midi) {
1307                 status = -ENOMEM;
1308                 goto setup_fail;
1309         }
1310 
1311         for (i = 0; i < opts->in_ports; i++)
1312                 midi->in_ports_array[i].cable = i;
1313 
1314         /* set up ALSA midi devices */
1315         midi->id = kstrdup(opts->id, GFP_KERNEL);
1316         if (opts->id && !midi->id) {
1317                 status = -ENOMEM;
1318                 goto setup_fail;
1319         }
1320         midi->in_ports = opts->in_ports;
1321         midi->out_ports = opts->out_ports;
1322         midi->index = opts->index;
1323         midi->buflen = opts->buflen;
1324         midi->qlen = opts->qlen;
1325         midi->in_last_port = 0;
1326         midi->free_ref = 1;
1327 
1328         status = kfifo_alloc(&midi->in_req_fifo, midi->qlen, GFP_KERNEL);
1329         if (status)
1330                 goto setup_fail;
1331 
1332         spin_lock_init(&midi->transmit_lock);
1333 
1334         ++opts->refcnt;
1335         mutex_unlock(&opts->lock);
1336 
1337         midi->func.name         = "gmidi function";
1338         midi->func.bind         = f_midi_bind;
1339         midi->func.unbind       = f_midi_unbind;
1340         midi->func.set_alt      = f_midi_set_alt;
1341         midi->func.disable      = f_midi_disable;
1342         midi->func.free_func    = f_midi_free;
1343 
1344         return &midi->func;
1345 
1346 setup_fail:
1347         mutex_unlock(&opts->lock);
1348         kfree(midi);
1349         return ERR_PTR(status);
1350 }
1351 
1352 DECLARE_USB_FUNCTION_INIT(midi, f_midi_alloc_inst, f_midi_alloc);
/* [<][>][^][v][top][bottom][index][help] */
root/drivers/usb/gadget/function/f_midi.c

DEFINITIONS
