drivers/usb/gadget/f_audio.c

   1 /*
   2  * f_audio.c -- USB Audio class function driver
   3   *
   4  * Copyright (C) 2008 Bryan Wu <cooloney@kernel.org>
   5  * Copyright (C) 2008 Analog Devices, Inc
   6  *
   7  * Enter bugs at http://blackfin.uclinux.org/
   8  *
   9  * Licensed under the GPL-2 or later.
  10  */
  11
  12 #include <linux/kernel.h>
  13 #include <linux/device.h>
  14 #include <asm/atomic.h>
  15
  16 #include "u_audio.h"
  17
  18 #define OUT_EP_MAX_PACKET_SIZE  200
  19 static int req_buf_size = OUT_EP_MAX_PACKET_SIZE;
  20 module_param(req_buf_size, int, S_IRUGO);
  21 MODULE_PARM_DESC(req_buf_size, "ISO OUT endpoint request buffer size");
  22
  23 static int req_count = 256;
  24 module_param(req_count, int, S_IRUGO);
  25 MODULE_PARM_DESC(req_count, "ISO OUT endpoint request count");
  26
  27 static int audio_buf_size = 48000;
  28 module_param(audio_buf_size, int, S_IRUGO);
  29 MODULE_PARM_DESC(audio_buf_size, "Audio buffer size");
  30
  31 static int generic_set_cmd(struct usb_audio_control *con, u8 cmd, int value);
  32 static int generic_get_cmd(struct usb_audio_control *con, u8 cmd);
  33
  34 /*
  35  * DESCRIPTORS ... most are static, but strings and full
  36  * configuration descriptors are built on demand.
  37  */
  38
  39 /*
  40  * We have two interfaces- AudioControl and AudioStreaming
  41  * TODO: only supcard playback currently
  42  */
  43 #define F_AUDIO_AC_INTERFACE    0
  44 #define F_AUDIO_AS_INTERFACE    1
  45 #define F_AUDIO_NUM_INTERFACES  2
  46
  47 /* B.3.1  Standard AC Interface Descriptor */
  48 static struct usb_interface_descriptor ac_interface_desc __initdata = {
  49         .bLength =              USB_DT_INTERFACE_SIZE,
  50         .bDescriptorType =      USB_DT_INTERFACE,
  51         .bNumEndpoints =        0,
  52         .bInterfaceClass =      USB_CLASS_AUDIO,
  53         .bInterfaceSubClass =   USB_SUBCLASS_AUDIOCONTROL,
  54 };
  55
  56 DECLARE_UAC_AC_HEADER_DESCRIPTOR(2);
  57
  58 #define UAC_DT_AC_HEADER_LENGTH UAC_DT_AC_HEADER_SIZE(F_AUDIO_NUM_INTERFACES)
  59 /* B.3.2  Class-Specific AC Interface Descriptor */
  60 static struct uac_ac_header_descriptor_2 ac_header_desc = {
  61         .bLength =              UAC_DT_AC_HEADER_LENGTH,
  62         .bDescriptorType =      USB_DT_CS_INTERFACE,
  63         .bDescriptorSubtype =   UAC_HEADER,
  64         .bcdADC =               __constant_cpu_to_le16(0x0100),
  65         .wTotalLength =         __constant_cpu_to_le16(UAC_DT_AC_HEADER_LENGTH),
  66         .bInCollection =        F_AUDIO_NUM_INTERFACES,
  67         .baInterfaceNr = {
  68                 [0] =           F_AUDIO_AC_INTERFACE,
  69                 [1] =           F_AUDIO_AS_INTERFACE,
  70         }
  71 };
  72
  73 #define INPUT_TERMINAL_ID       1
  74 static struct uac_input_terminal_descriptor input_terminal_desc = {
  75         .bLength =              UAC_DT_INPUT_TERMINAL_SIZE,
  76         .bDescriptorType =      USB_DT_CS_INTERFACE,
  77         .bDescriptorSubtype =   UAC_INPUT_TERMINAL,
  78         .bTerminalID =          INPUT_TERMINAL_ID,
  79         .wTerminalType =        UAC_TERMINAL_STREAMING,
  80         .bAssocTerminal =       0,
  81         .wChannelConfig =       0x3,
  82 };
  83
  84 DECLARE_UAC_FEATURE_UNIT_DESCRIPTOR(0);
  85
  86 #define FEATURE_UNIT_ID         2
  87 static struct uac_feature_unit_descriptor_0 feature_unit_desc = {
  88         .bLength                = UAC_DT_FEATURE_UNIT_SIZE(0),
  89         .bDescriptorType        = USB_DT_CS_INTERFACE,
  90         .bDescriptorSubtype     = UAC_FEATURE_UNIT,
  91         .bUnitID                = FEATURE_UNIT_ID,
  92         .bSourceID              = INPUT_TERMINAL_ID,
  93         .bControlSize           = 2,
  94         .bmaControls[0]         = (UAC_FU_MUTE | UAC_FU_VOLUME),
  95 };
  96
  97 static struct usb_audio_control mute_control = {
  98         .list = LIST_HEAD_INIT(mute_control.list),
  99         .name = "Mute Control",
 100         .type = UAC_MUTE_CONTROL,
 101         /* Todo: add real Mute control code */
 102         .set = generic_set_cmd,
 103         .get = generic_get_cmd,
 104 };
 105
 106 static struct usb_audio_control volume_control = {
 107         .list = LIST_HEAD_INIT(volume_control.list),
 108         .name = "Volume Control",
 109         .type = UAC_VOLUME_CONTROL,
 110         /* Todo: add real Volume control code */
 111         .set = generic_set_cmd,
 112         .get = generic_get_cmd,
 113 };
 114
 115 static struct usb_audio_control_selector feature_unit = {
 116         .list = LIST_HEAD_INIT(feature_unit.list),
 117         .id = FEATURE_UNIT_ID,
 118         .name = "Mute & Volume Control",
 119         .type = UAC_FEATURE_UNIT,
 120         .desc = (struct usb_descriptor_header *)&feature_unit_desc,
 121 };
 122
 123 #define OUTPUT_TERMINAL_ID      3
 124 static struct uac_output_terminal_descriptor output_terminal_desc = {
 125         .bLength                = UAC_DT_OUTPUT_TERMINAL_SIZE,
 126         .bDescriptorType        = USB_DT_CS_INTERFACE,
 127         .bDescriptorSubtype     = UAC_OUTPUT_TERMINAL,
 128         .bTerminalID            = OUTPUT_TERMINAL_ID,
 129         .wTerminalType          = UAC_OUTPUT_TERMINAL_SPEAKER,
 130         .bAssocTerminal         = FEATURE_UNIT_ID,
 131         .bSourceID              = FEATURE_UNIT_ID,
 132 };
 133
 134 /* B.4.1  Standard AS Interface Descriptor */
 135 static struct usb_interface_descriptor as_interface_alt_0_desc = {
 136         .bLength =              USB_DT_INTERFACE_SIZE,
 137         .bDescriptorType =      USB_DT_INTERFACE,
 138         .bAlternateSetting =    0,
 139         .bNumEndpoints =        0,
 140         .bInterfaceClass =      USB_CLASS_AUDIO,
 141         .bInterfaceSubClass =   USB_SUBCLASS_AUDIOSTREAMING,
 142 };
 143
 144 static struct usb_interface_descriptor as_interface_alt_1_desc = {
 145         .bLength =              USB_DT_INTERFACE_SIZE,
 146         .bDescriptorType =      USB_DT_INTERFACE,
 147         .bAlternateSetting =    1,
 148         .bNumEndpoints =        1,
 149         .bInterfaceClass =      USB_CLASS_AUDIO,
 150         .bInterfaceSubClass =   USB_SUBCLASS_AUDIOSTREAMING,
 151 };
 152
 153 /* B.4.2  Class-Specific AS Interface Descriptor */
 154 static struct uac_as_header_descriptor as_header_desc = {
 155         .bLength =              UAC_DT_AS_HEADER_SIZE,
 156         .bDescriptorType =      USB_DT_CS_INTERFACE,
 157         .bDescriptorSubtype =   UAC_AS_GENERAL,
 158         .bTerminalLink =        INPUT_TERMINAL_ID,
 159         .bDelay =               1,
 160         .wFormatTag =           UAC_FORMAT_TYPE_I_PCM,
 161 };
 162
 163 DECLARE_UAC_FORMAT_TYPE_I_DISCRETE_DESC(1);
 164
 165 static struct uac_format_type_i_discrete_descriptor_1 as_type_i_desc = {
 166         .bLength =              UAC_FORMAT_TYPE_I_DISCRETE_DESC_SIZE(1),
 167         .bDescriptorType =      USB_DT_CS_INTERFACE,
 168         .bDescriptorSubtype =   UAC_FORMAT_TYPE,
 169         .bFormatType =          UAC_FORMAT_TYPE_I,
 170         .bSubframeSize =        2,
 171         .bBitResolution =       16,
 172         .bSamFreqType =         1,
 173 };
 174
 175 /* Standard ISO OUT Endpoint Descriptor */
 176 static struct usb_endpoint_descriptor as_out_ep_desc __initdata = {
 177         .bLength =              USB_DT_ENDPOINT_AUDIO_SIZE,
 178         .bDescriptorType =      USB_DT_ENDPOINT,
 179         .bEndpointAddress =     USB_DIR_OUT,
 180         .bmAttributes =         USB_ENDPOINT_SYNC_ADAPTIVE
 181                                 | USB_ENDPOINT_XFER_ISOC,
 182         .wMaxPacketSize =       __constant_cpu_to_le16(OUT_EP_MAX_PACKET_SIZE),
 183         .bInterval =            4,
 184 };
 185
 186 /* Class-specific AS ISO OUT Endpoint Descriptor */
 187 static struct uac_iso_endpoint_descriptor as_iso_out_desc __initdata = {
 188         .bLength =              UAC_ISO_ENDPOINT_DESC_SIZE,
 189         .bDescriptorType =      USB_DT_CS_ENDPOINT,
 190         .bDescriptorSubtype =   UAC_EP_GENERAL,
 191         .bmAttributes =         1,
 192         .bLockDelayUnits =      1,
 193         .wLockDelay =           __constant_cpu_to_le16(1),
 194 };
 195
 196 static struct usb_descriptor_header *f_audio_desc[] __initdata = {
 197         (struct usb_descriptor_header *)&ac_interface_desc,
 198         (struct usb_descriptor_header *)&ac_header_desc,
 199
 200         (struct usb_descriptor_header *)&input_terminal_desc,
 201         (struct usb_descriptor_header *)&output_terminal_desc,
 202         (struct usb_descriptor_header *)&feature_unit_desc,
 203
 204         (struct usb_descriptor_header *)&as_interface_alt_0_desc,
 205         (struct usb_descriptor_header *)&as_interface_alt_1_desc,
 206         (struct usb_descriptor_header *)&as_header_desc,
 207
 208         (struct usb_descriptor_header *)&as_type_i_desc,
 209
 210         (struct usb_descriptor_header *)&as_out_ep_desc,
 211         (struct usb_descriptor_header *)&as_iso_out_desc,
 212         NULL,
 213 };
 214
 215 /* string IDs are assigned dynamically */
 216
 217 #define STRING_MANUFACTURER_IDX         0
 218 #define STRING_PRODUCT_IDX              1
 219
 220 static char manufacturer[50];
 221
 222 static struct usb_string strings_dev[] = {
 223         [STRING_MANUFACTURER_IDX].s = manufacturer,
 224         [STRING_PRODUCT_IDX].s = DRIVER_DESC,
 225         {  } /* end of list */
 226 };
 227
 228 static struct usb_gadget_strings stringtab_dev = {
 229         .language       = 0x0409,       /* en-us */
 230         .strings        = strings_dev,
 231 };
 232
 233 static struct usb_gadget_strings *audio_strings[] = {
 234         &stringtab_dev,
 235         NULL,
 236 };
 237
 238 /*
 239  * This function is an ALSA sound card following USB Audio Class Spec 1.0.
 240  */
 241
 242 /*-------------------------------------------------------------------------*/
 243 struct f_audio_buf {
 244         u8 *buf;
 245         int actual;
 246         struct list_head list;
 247 };
 248
 249 static struct f_audio_buf *f_audio_buffer_alloc(int buf_size)
 250 {
 251         struct f_audio_buf *copy_buf;
 252
 253         copy_buf = kzalloc(sizeof *copy_buf, GFP_ATOMIC);
 254         if (!copy_buf)
 255                 return ERR_PTR(-ENOMEM);
 256
 257         copy_buf->buf = kzalloc(buf_size, GFP_ATOMIC);
 258         if (!copy_buf->buf) {
 259                 kfree(copy_buf);
 260                 return ERR_PTR(-ENOMEM);
 261         }
 262
 263         return copy_buf;
 264 }
 265
 266 static void f_audio_buffer_free(struct f_audio_buf *audio_buf)
 267 {
 268         kfree(audio_buf->buf);
 269         kfree(audio_buf);
 270 }
 271 /*-------------------------------------------------------------------------*/
 272
 273 struct f_audio {
 274         struct gaudio                   card;
 275
 276         /* endpoints handle full and/or high speeds */
 277         struct usb_ep                   *out_ep;
 278         struct usb_endpoint_descriptor  *out_desc;
 279
 280         spinlock_t                      lock;
 281         struct f_audio_buf *copy_buf;
 282         struct work_struct playback_work;
 283         struct list_head play_queue;
 284
 285         /* Control Set command */
 286         struct list_head cs;
 287         u8 set_cmd;
 288         struct usb_audio_control *set_con;
 289 };
 290
 291 static inline struct f_audio *func_to_audio(struct usb_function *f)
 292 {
 293         return container_of(f, struct f_audio, card.func);
 294 }
 295
 296 /*-------------------------------------------------------------------------*/
 297
 298 static void f_audio_playback_work(struct work_struct *data)
 299 {
 300         struct f_audio *audio = container_of(data, struct f_audio,
 301                                         playback_work);
 302         struct f_audio_buf *play_buf;
 303
 304         spin_lock_irq(&audio->lock);
 305         if (list_empty(&audio->play_queue)) {
 306                 spin_unlock_irq(&audio->lock);
 307                 return;
 308         }
 309         play_buf = list_first_entry(&audio->play_queue,
 310                         struct f_audio_buf, list);
 311         list_del(&play_buf->list);
 312         spin_unlock_irq(&audio->lock);
 313
 314         u_audio_playback(&audio->card, play_buf->buf, play_buf->actual);
 315         f_audio_buffer_free(play_buf);
 316
 317         return;
 318 }
 319
 320 static int f_audio_out_ep_complete(struct usb_ep *ep, struct usb_request *req)
 321 {
 322         struct f_audio *audio = req->context;
 323         struct usb_composite_dev *cdev = audio->card.func.config->cdev;
 324         struct f_audio_buf *copy_buf = audio->copy_buf;
 325         int err;
 326
 327         if (!copy_buf)
 328                 return -EINVAL;
 329
 330         /* Copy buffer is full, add it to the play_queue */
 331         if (audio_buf_size - copy_buf->actual < req->actual) {
 332                 list_add_tail(&copy_buf->list, &audio->play_queue);
 333                 schedule_work(&audio->playback_work);
 334                 copy_buf = f_audio_buffer_alloc(audio_buf_size);
 335                 if (IS_ERR(copy_buf))
 336                         return -ENOMEM;
 337         }
 338
 339         memcpy(copy_buf->buf + copy_buf->actual, req->buf, req->actual);
 340         copy_buf->actual += req->actual;
 341         audio->copy_buf = copy_buf;
 342
 343         err = usb_ep_queue(ep, req, GFP_ATOMIC);
 344         if (err)
 345                 ERROR(cdev, "%s queue req: %d\n", ep->name, err);
 346
 347         return 0;
 348
 349 }
 350
 351 static void f_audio_complete(struct usb_ep *ep, struct usb_request *req)
 352 {
 353         struct f_audio *audio = req->context;
 354         int status = req->status;
 355         u32 data = 0;
 356         struct usb_ep *out_ep = audio->out_ep;
 357
 358         switch (status) {
 359
 360         case 0:                         /* normal completion? */
 361                 if (ep == out_ep)
 362                         f_audio_out_ep_complete(ep, req);
 363                 else if (audio->set_con) {
 364                         memcpy(&data, req->buf, req->length);
 365                         audio->set_con->set(audio->set_con, audio->set_cmd,
 366                                         le16_to_cpu(data));
 367                         audio->set_con = NULL;
 368                 }
 369                 break;
 370         default:
 371                 break;
 372         }
 373 }
 374
 375 static int audio_set_intf_req(struct usb_function *f,
 376                 const struct usb_ctrlrequest *ctrl)
 377 {
 378         struct f_audio          *audio = func_to_audio(f);
 379         struct usb_composite_dev *cdev = f->config->cdev;
 380         struct usb_request      *req = cdev->req;
 381         u8                      id = ((le16_to_cpu(ctrl->wIndex) >> 8) & 0xFF);
 382         u16                     len = le16_to_cpu(ctrl->wLength);
 383         u16                     w_value = le16_to_cpu(ctrl->wValue);
 384         u8                      con_sel = (w_value >> 8) & 0xFF;
 385         u8                      cmd = (ctrl->bRequest & 0x0F);
 386         struct usb_audio_control_selector *cs;
 387         struct usb_audio_control *con;
 388
 389         DBG(cdev, "bRequest 0x%x, w_value 0x%04x, len %d, entity %d\n",
 390                         ctrl->bRequest, w_value, len, id);
 391
 392         list_for_each_entry(cs, &audio->cs, list) {
 393                 if (cs->id == id) {
 394                         list_for_each_entry(con, &cs->control, list) {
 395                                 if (con->type == con_sel) {
 396                                         audio->set_con = con;
 397                                         break;
 398                                 }
 399                         }
 400                         break;
 401                 }
 402         }
 403
 404         audio->set_cmd = cmd;
 405         req->context = audio;
 406         req->complete = f_audio_complete;
 407
 408         return len;
 409 }
 410
 411 static int audio_get_intf_req(struct usb_function *f,
 412                 const struct usb_ctrlrequest *ctrl)
 413 {
 414         struct f_audio          *audio = func_to_audio(f);
 415         struct usb_composite_dev *cdev = f->config->cdev;
 416         struct usb_request      *req = cdev->req;
 417         int                     value = -EOPNOTSUPP;
 418         u8                      id = ((le16_to_cpu(ctrl->wIndex) >> 8) & 0xFF);
 419         u16                     len = le16_to_cpu(ctrl->wLength);
 420         u16                     w_value = le16_to_cpu(ctrl->wValue);
 421         u8                      con_sel = (w_value >> 8) & 0xFF;
 422         u8                      cmd = (ctrl->bRequest & 0x0F);
 423         struct usb_audio_control_selector *cs;
 424         struct usb_audio_control *con;
 425
 426         DBG(cdev, "bRequest 0x%x, w_value 0x%04x, len %d, entity %d\n",
 427                         ctrl->bRequest, w_value, len, id);
 428
 429         list_for_each_entry(cs, &audio->cs, list) {
 430                 if (cs->id == id) {
 431                         list_for_each_entry(con, &cs->control, list) {
 432                                 if (con->type == con_sel && con->get) {
 433                                         value = con->get(con, cmd);
 434                                         break;
 435                                 }
 436                         }
 437                         break;
 438                 }
 439         }
 440
 441         req->context = audio;
 442         req->complete = f_audio_complete;
 443         memcpy(req->buf, &value, len);
 444
 445         return len;
 446 }
 447
 448 static int audio_set_endpoint_req(struct usb_function *f,
 449                 const struct usb_ctrlrequest *ctrl)
 450 {
 451         struct usb_composite_dev *cdev = f->config->cdev;
 452         int                     value = -EOPNOTSUPP;
 453         u16                     ep = le16_to_cpu(ctrl->wIndex);
 454         u16                     len = le16_to_cpu(ctrl->wLength);
 455         u16                     w_value = le16_to_cpu(ctrl->wValue);
 456
 457         DBG(cdev, "bRequest 0x%x, w_value 0x%04x, len %d, endpoint %d\n",
 458                         ctrl->bRequest, w_value, len, ep);
 459
 460         switch (ctrl->bRequest) {
 461         case UAC_SET_CUR:
 462                 value = 0;
 463                 break;
 464
 465         case UAC_SET_MIN:
 466                 break;
 467
 468         case UAC_SET_MAX:
 469                 break;
 470
 471         case UAC_SET_RES:
 472                 break;
 473
 474         case UAC_SET_MEM:
 475                 break;
 476
 477         default:
 478                 break;
 479         }
 480
 481         return value;
 482 }
 483
 484 static int audio_get_endpoint_req(struct usb_function *f,
 485                 const struct usb_ctrlrequest *ctrl)
 486 {
 487         struct usb_composite_dev *cdev = f->config->cdev;
 488         int value = -EOPNOTSUPP;
 489         u8 ep = ((le16_to_cpu(ctrl->wIndex) >> 8) & 0xFF);
 490         u16 len = le16_to_cpu(ctrl->wLength);
 491         u16 w_value = le16_to_cpu(ctrl->wValue);
 492
 493         DBG(cdev, "bRequest 0x%x, w_value 0x%04x, len %d, endpoint %d\n",
 494                         ctrl->bRequest, w_value, len, ep);
 495
 496         switch (ctrl->bRequest) {
 497         case UAC_GET_CUR:
 498         case UAC_GET_MIN:
 499         case UAC_GET_MAX:
 500         case UAC_GET_RES:
 501                 value = 3;
 502                 break;
 503         case UAC_GET_MEM:
 504                 break;
 505         default:
 506                 break;
 507         }
 508
 509         return value;
 510 }
 511
 512 static int
 513 f_audio_setup(struct usb_function *f, const struct usb_ctrlrequest *ctrl)
 514 {
 515         struct usb_composite_dev *cdev = f->config->cdev;
 516         struct usb_request      *req = cdev->req;
 517         int                     value = -EOPNOTSUPP;
 518         u16                     w_index = le16_to_cpu(ctrl->wIndex);
 519         u16                     w_value = le16_to_cpu(ctrl->wValue);
 520         u16                     w_length = le16_to_cpu(ctrl->wLength);
 521
 522         /* composite driver infrastructure handles everything; interface
 523          * activation uses set_alt().
 524          */
 525         switch (ctrl->bRequestType) {
 526         case USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE:
 527                 value = audio_set_intf_req(f, ctrl);
 528                 break;
 529
 530         case USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE:
 531                 value = audio_get_intf_req(f, ctrl);
 532                 break;
 533
 534         case USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_ENDPOINT:
 535                 value = audio_set_endpoint_req(f, ctrl);
 536                 break;
 537
 538         case USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_ENDPOINT:
 539                 value = audio_get_endpoint_req(f, ctrl);
 540                 break;
 541
 542         default:
 543                 ERROR(cdev, "invalid control req%02x.%02x v%04x i%04x l%d\n",
 544                         ctrl->bRequestType, ctrl->bRequest,
 545                         w_value, w_index, w_length);
 546         }
 547
 548         /* respond with data transfer or status phase? */
 549         if (value >= 0) {
 550                 DBG(cdev, "audio req%02x.%02x v%04x i%04x l%d\n",
 551                         ctrl->bRequestType, ctrl->bRequest,
 552                         w_value, w_index, w_length);
 553                 req->zero = 0;
 554                 req->length = value;
 555                 value = usb_ep_queue(cdev->gadget->ep0, req, GFP_ATOMIC);
 556                 if (value < 0)
 557                         ERROR(cdev, "audio response on err %d\n", value);
 558         }
 559
 560         /* device either stalls (value < 0) or reports success */
 561         return value;
 562 }
 563
 564 static int f_audio_set_alt(struct usb_function *f, unsigned intf, unsigned alt)
 565 {
 566         struct f_audio          *audio = func_to_audio(f);
 567         struct usb_composite_dev *cdev = f->config->cdev;
 568         struct usb_ep *out_ep = audio->out_ep;
 569         struct usb_request *req;
 570         int i = 0, err = 0;
 571
 572         DBG(cdev, "intf %d, alt %d\n", intf, alt);
 573
 574         if (intf == 1) {
 575                 if (alt == 1) {
 576                         usb_ep_enable(out_ep, audio->out_desc);
 577                         out_ep->driver_data = audio;
 578                         audio->copy_buf = f_audio_buffer_alloc(audio_buf_size);
 579                         if (IS_ERR(audio->copy_buf))
 580                                 return -ENOMEM;
 581
 582                         /*
 583                          * allocate a bunch of read buffers
 584                          * and queue them all at once.
 585                          */
 586                         for (i = 0; i < req_count && err == 0; i++) {
 587                                 req = usb_ep_alloc_request(out_ep, GFP_ATOMIC);
 588                                 if (req) {
 589                                         req->buf = kzalloc(req_buf_size,
 590                                                         GFP_ATOMIC);
 591                                         if (req->buf) {
 592                                                 req->length = req_buf_size;
 593                                                 req->context = audio;
 594                                                 req->complete =
 595                                                         f_audio_complete;
 596                                                 err = usb_ep_queue(out_ep,
 597                                                         req, GFP_ATOMIC);
 598                                                 if (err)
 599                                                         ERROR(cdev,
 600                                                         "%s queue req: %d\n",
 601                                                         out_ep->name, err);
 602                                         } else
 603                                                 err = -ENOMEM;
 604                                 } else
 605                                         err = -ENOMEM;
 606                         }
 607
 608                 } else {
 609                         struct f_audio_buf *copy_buf = audio->copy_buf;
 610                         if (copy_buf) {
 611                                 list_add_tail(&copy_buf->list,
 612                                                 &audio->play_queue);
 613                                 schedule_work(&audio->playback_work);
 614                         }
 615                 }
 616         }
 617
 618         return err;
 619 }
 620
 621 static void f_audio_disable(struct usb_function *f)
 622 {
 623         return;
 624 }
 625
 626 /*-------------------------------------------------------------------------*/
 627
 628 static void f_audio_build_desc(struct f_audio *audio)
 629 {
 630         struct gaudio *card = &audio->card;
 631         u8 *sam_freq;
 632         int rate;
 633
 634         /* Set channel numbers */
 635         input_terminal_desc.bNrChannels = u_audio_get_playback_channels(card);
 636         as_type_i_desc.bNrChannels = u_audio_get_playback_channels(card);
 637
 638         /* Set sample rates */
 639         rate = u_audio_get_playback_rate(card);
 640         sam_freq = as_type_i_desc.tSamFreq[0];
 641         memcpy(sam_freq, &rate, 3);
 642
 643         /* Todo: Set Sample bits and other parameters */
 644
 645         return;
 646 }
 647
 648 /* audio function driver setup/binding */
 649 static int __init
 650 f_audio_bind(struct usb_configuration *c, struct usb_function *f)
 651 {
 652         struct usb_composite_dev *cdev = c->cdev;
 653         struct f_audio          *audio = func_to_audio(f);
 654         int                     status;
 655         struct usb_ep           *ep;
 656
 657         f_audio_build_desc(audio);
 658
 659         /* allocate instance-specific interface IDs, and patch descriptors */
 660         status = usb_interface_id(c, f);
 661         if (status < 0)
 662                 goto fail;
 663         ac_interface_desc.bInterfaceNumber = status;
 664
 665         status = usb_interface_id(c, f);
 666         if (status < 0)
 667                 goto fail;
 668         as_interface_alt_0_desc.bInterfaceNumber = status;
 669         as_interface_alt_1_desc.bInterfaceNumber = status;
 670
 671         status = -ENODEV;
 672
 673         /* allocate instance-specific endpoints */
 674         ep = usb_ep_autoconfig(cdev->gadget, &as_out_ep_desc);
 675         if (!ep)
 676                 goto fail;
 677         audio->out_ep = ep;
 678         ep->driver_data = cdev; /* claim */
 679
 680         status = -ENOMEM;
 681
 682         /* supcard all relevant hardware speeds... we expect that when
 683          * hardware is dual speed, all bulk-capable endpoints work at
 684          * both speeds
 685          */
 686
 687         /* copy descriptors, and track endpoint copies */
 688         if (gadget_is_dualspeed(c->cdev->gadget)) {
 689                 c->highspeed = true;
 690                 f->hs_descriptors = usb_copy_descriptors(f_audio_desc);
 691         } else
 692                 f->descriptors = usb_copy_descriptors(f_audio_desc);
 693
 694         return 0;
 695
 696 fail:
 697
 698         return status;
 699 }
 700
 701 static void
 702 f_audio_unbind(struct usb_configuration *c, struct usb_function *f)
 703 {
 704         struct f_audio          *audio = func_to_audio(f);
 705
 706         usb_free_descriptors(f->descriptors);
 707         kfree(audio);
 708 }
 709
 710 /*-------------------------------------------------------------------------*/
 711
 712 static int generic_set_cmd(struct usb_audio_control *con, u8 cmd, int value)
 713 {
 714         con->data[cmd] = value;
 715
 716         return 0;
 717 }
 718
 719 static int generic_get_cmd(struct usb_audio_control *con, u8 cmd)
 720 {
 721         return con->data[cmd];
 722 }
 723
 724 /* Todo: add more control selecotor dynamically */
 725 int __init control_selector_init(struct f_audio *audio)
 726 {
 727         INIT_LIST_HEAD(&audio->cs);
 728         list_add(&feature_unit.list, &audio->cs);
 729
 730         INIT_LIST_HEAD(&feature_unit.control);
 731         list_add(&mute_control.list, &feature_unit.control);
 732         list_add(&volume_control.list, &feature_unit.control);
 733
 734         volume_control.data[UAC__CUR] = 0xffc0;
 735         volume_control.data[UAC__MIN] = 0xe3a0;
 736         volume_control.data[UAC__MAX] = 0xfff0;
 737         volume_control.data[UAC__RES] = 0x0030;
 738
 739         return 0;
 740 }
 741
 742 /**
 743  * audio_bind_config - add USB audio fucntion to a configuration
 744  * @c: the configuration to supcard the USB audio function
 745  * Context: single threaded during gadget setup
 746  *
 747  * Returns zero on success, else negative errno.
 748  */
 749 int __init audio_bind_config(struct usb_configuration *c)
 750 {
 751         struct f_audio *audio;
 752         int status;
 753
 754         /* allocate and initialize one new instance */
 755         audio = kzalloc(sizeof *audio, GFP_KERNEL);
 756         if (!audio)
 757                 return -ENOMEM;
 758
 759         audio->card.func.name = "g_audio";
 760         audio->card.gadget = c->cdev->gadget;
 761
 762         INIT_LIST_HEAD(&audio->play_queue);
 763         spin_lock_init(&audio->lock);
 764
 765         /* set up ASLA audio devices */
 766         status = gaudio_setup(&audio->card);
 767         if (status < 0)
 768                 goto setup_fail;
 769
 770         audio->card.func.strings = audio_strings;
 771         audio->card.func.bind = f_audio_bind;
 772         audio->card.func.unbind = f_audio_unbind;
 773         audio->card.func.set_alt = f_audio_set_alt;
 774         audio->card.func.setup = f_audio_setup;
 775         audio->card.func.disable = f_audio_disable;
 776         audio->out_desc = &as_out_ep_desc;
 777
 778         control_selector_init(audio);
 779
 780         INIT_WORK(&audio->playback_work, f_audio_playback_work);
 781
 782         status = usb_add_function(c, &audio->card.func);
 783         if (status)
 784                 goto add_fail;
 785
 786         INFO(c->cdev, "audio_buf_size %d, req_buf_size %d, req_count %d\n",
 787                 audio_buf_size, req_buf_size, req_count);
 788
 789         return status;
 790
 791 add_fail:
 792         gaudio_cleanup(&audio->card);
 793 setup_fail:
 794         kfree(audio);
 795         return status;
 796 }