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/slab.h>
  13 #include <linux/kernel.h>
  14 #include <linux/device.h>
  15 #include <linux/atomic.h>
  16
  17 #include "u_audio.h"
  18
  19 #define OUT_EP_MAX_PACKET_SIZE  200
  20 static int req_buf_size = OUT_EP_MAX_PACKET_SIZE;
  21 module_param(req_buf_size, int, S_IRUGO);
  22 MODULE_PARM_DESC(req_buf_size, "ISO OUT endpoint request buffer size");
  23
  24 static int req_count = 256;
  25 module_param(req_count, int, S_IRUGO);
  26 MODULE_PARM_DESC(req_count, "ISO OUT endpoint request count");
  27
  28 static int audio_buf_size = 48000;
  29 module_param(audio_buf_size, int, S_IRUGO);
  30 MODULE_PARM_DESC(audio_buf_size, "Audio buffer size");
  31
  32 static int generic_set_cmd(struct usb_audio_control *con, u8 cmd, int value);
  33 static int generic_get_cmd(struct usb_audio_control *con, u8 cmd);
  34
  35 /*
  36  * DESCRIPTORS ... most are static, but strings and full
  37  * configuration descriptors are built on demand.
  38  */
  39
  40 /*
  41  * We have two interfaces- AudioControl and AudioStreaming
  42  * TODO: only supcard playback currently
  43  */
  44 #define F_AUDIO_AC_INTERFACE    0
  45 #define F_AUDIO_AS_INTERFACE    1
  46 #define F_AUDIO_NUM_INTERFACES  2
  47
  48 /* B.3.1  Standard AC Interface Descriptor */
  49 static struct usb_interface_descriptor ac_interface_desc __initdata = {
  50         .bLength =              USB_DT_INTERFACE_SIZE,
  51         .bDescriptorType =      USB_DT_INTERFACE,
  52         .bNumEndpoints =        0,
  53         .bInterfaceClass =      USB_CLASS_AUDIO,
  54         .bInterfaceSubClass =   USB_SUBCLASS_AUDIOCONTROL,
  55 };
  56
  57 DECLARE_UAC_AC_HEADER_DESCRIPTOR(2);
  58
  59 #define UAC_DT_AC_HEADER_LENGTH UAC_DT_AC_HEADER_SIZE(F_AUDIO_NUM_INTERFACES)
  60 /* 1 input terminal, 1 output terminal and 1 feature unit */
  61 #define UAC_DT_TOTAL_LENGTH (UAC_DT_AC_HEADER_LENGTH + UAC_DT_INPUT_TERMINAL_SIZE \
  62         + UAC_DT_OUTPUT_TERMINAL_SIZE + UAC_DT_FEATURE_UNIT_SIZE(0))
  63 /* B.3.2  Class-Specific AC Interface Descriptor */
  64 static struct uac1_ac_header_descriptor_2 ac_header_desc = {
  65         .bLength =              UAC_DT_AC_HEADER_LENGTH,
  66         .bDescriptorType =      USB_DT_CS_INTERFACE,
  67         .bDescriptorSubtype =   UAC_HEADER,
  68         .bcdADC =               __constant_cpu_to_le16(0x0100),
  69         .wTotalLength =         __constant_cpu_to_le16(UAC_DT_TOTAL_LENGTH),
  70         .bInCollection =        F_AUDIO_NUM_INTERFACES,
  71         .baInterfaceNr = {
  72                 [0] =           F_AUDIO_AC_INTERFACE,
  73                 [1] =           F_AUDIO_AS_INTERFACE,
  74         }
  75 };
  76
  77 #define INPUT_TERMINAL_ID       1
  78 static struct uac_input_terminal_descriptor input_terminal_desc = {
  79         .bLength =              UAC_DT_INPUT_TERMINAL_SIZE,
  80         .bDescriptorType =      USB_DT_CS_INTERFACE,
  81         .bDescriptorSubtype =   UAC_INPUT_TERMINAL,
  82         .bTerminalID =          INPUT_TERMINAL_ID,
  83         .wTerminalType =        UAC_TERMINAL_STREAMING,
  84         .bAssocTerminal =       0,
  85         .wChannelConfig =       0x3,
  86 };
  87
  88 DECLARE_UAC_FEATURE_UNIT_DESCRIPTOR(0);
  89
  90 #define FEATURE_UNIT_ID         2
  91 static struct uac_feature_unit_descriptor_0 feature_unit_desc = {
  92         .bLength                = UAC_DT_FEATURE_UNIT_SIZE(0),
  93         .bDescriptorType        = USB_DT_CS_INTERFACE,
  94         .bDescriptorSubtype     = UAC_FEATURE_UNIT,
  95         .bUnitID                = FEATURE_UNIT_ID,
  96         .bSourceID              = INPUT_TERMINAL_ID,
  97         .bControlSize           = 2,
  98         .bmaControls[0]         = (UAC_FU_MUTE | UAC_FU_VOLUME),
  99 };
 100
 101 static struct usb_audio_control mute_control = {
 102         .list = LIST_HEAD_INIT(mute_control.list),
 103         .name = "Mute Control",
 104         .type = UAC_FU_MUTE,
 105         /* Todo: add real Mute control code */
 106         .set = generic_set_cmd,
 107         .get = generic_get_cmd,
 108 };
 109
 110 static struct usb_audio_control volume_control = {
 111         .list = LIST_HEAD_INIT(volume_control.list),
 112         .name = "Volume Control",
 113         .type = UAC_FU_VOLUME,
 114         /* Todo: add real Volume control code */
 115         .set = generic_set_cmd,
 116         .get = generic_get_cmd,
 117 };
 118
 119 static struct usb_audio_control_selector feature_unit = {
 120         .list = LIST_HEAD_INIT(feature_unit.list),
 121         .id = FEATURE_UNIT_ID,
 122         .name = "Mute & Volume Control",
 123         .type = UAC_FEATURE_UNIT,
 124         .desc = (struct usb_descriptor_header *)&feature_unit_desc,
 125 };
 126
 127 #define OUTPUT_TERMINAL_ID      3
 128 static struct uac1_output_terminal_descriptor output_terminal_desc = {
 129         .bLength                = UAC_DT_OUTPUT_TERMINAL_SIZE,
 130         .bDescriptorType        = USB_DT_CS_INTERFACE,
 131         .bDescriptorSubtype     = UAC_OUTPUT_TERMINAL,
 132         .bTerminalID            = OUTPUT_TERMINAL_ID,
 133         .wTerminalType          = UAC_OUTPUT_TERMINAL_SPEAKER,
 134         .bAssocTerminal         = FEATURE_UNIT_ID,
 135         .bSourceID              = FEATURE_UNIT_ID,
 136 };
 137
 138 /* B.4.1  Standard AS Interface Descriptor */
 139 static struct usb_interface_descriptor as_interface_alt_0_desc = {
 140         .bLength =              USB_DT_INTERFACE_SIZE,
 141         .bDescriptorType =      USB_DT_INTERFACE,
 142         .bAlternateSetting =    0,
 143         .bNumEndpoints =        0,
 144         .bInterfaceClass =      USB_CLASS_AUDIO,
 145         .bInterfaceSubClass =   USB_SUBCLASS_AUDIOSTREAMING,
 146 };
 147
 148 static struct usb_interface_descriptor as_interface_alt_1_desc = {
 149         .bLength =              USB_DT_INTERFACE_SIZE,
 150         .bDescriptorType =      USB_DT_INTERFACE,
 151         .bAlternateSetting =    1,
 152         .bNumEndpoints =        1,
 153         .bInterfaceClass =      USB_CLASS_AUDIO,
 154         .bInterfaceSubClass =   USB_SUBCLASS_AUDIOSTREAMING,
 155 };
 156
 157 /* B.4.2  Class-Specific AS Interface Descriptor */
 158 static struct uac1_as_header_descriptor as_header_desc = {
 159         .bLength =              UAC_DT_AS_HEADER_SIZE,
 160         .bDescriptorType =      USB_DT_CS_INTERFACE,
 161         .bDescriptorSubtype =   UAC_AS_GENERAL,
 162         .bTerminalLink =        INPUT_TERMINAL_ID,
 163         .bDelay =               1,
 164         .wFormatTag =           UAC_FORMAT_TYPE_I_PCM,
 165 };
 166
 167 DECLARE_UAC_FORMAT_TYPE_I_DISCRETE_DESC(1);
 168
 169 static struct uac_format_type_i_discrete_descriptor_1 as_type_i_desc = {
 170         .bLength =              UAC_FORMAT_TYPE_I_DISCRETE_DESC_SIZE(1),
 171         .bDescriptorType =      USB_DT_CS_INTERFACE,
 172         .bDescriptorSubtype =   UAC_FORMAT_TYPE,
 173         .bFormatType =          UAC_FORMAT_TYPE_I,
 174         .bSubframeSize =        2,
 175         .bBitResolution =       16,
 176         .bSamFreqType =         1,
 177 };
 178
 179 /* Standard ISO OUT Endpoint Descriptor */
 180 static struct usb_endpoint_descriptor as_out_ep_desc  = {
 181         .bLength =              USB_DT_ENDPOINT_AUDIO_SIZE,
 182         .bDescriptorType =      USB_DT_ENDPOINT,
 183         .bEndpointAddress =     USB_DIR_OUT,
 184         .bmAttributes =         USB_ENDPOINT_SYNC_ADAPTIVE
 185                                 | USB_ENDPOINT_XFER_ISOC,
 186         .wMaxPacketSize =       __constant_cpu_to_le16(OUT_EP_MAX_PACKET_SIZE),
 187         .bInterval =            4,
 188 };
 189
 190 /* Class-specific AS ISO OUT Endpoint Descriptor */
 191 static struct uac_iso_endpoint_descriptor as_iso_out_desc __initdata = {
 192         .bLength =              UAC_ISO_ENDPOINT_DESC_SIZE,
 193         .bDescriptorType =      USB_DT_CS_ENDPOINT,
 194         .bDescriptorSubtype =   UAC_EP_GENERAL,
 195         .bmAttributes =         1,
 196         .bLockDelayUnits =      1,
 197         .wLockDelay =           __constant_cpu_to_le16(1),
 198 };
 199
 200 static struct usb_descriptor_header *f_audio_desc[] __initdata = {
 201         (struct usb_descriptor_header *)&ac_interface_desc,
 202         (struct usb_descriptor_header *)&ac_header_desc,
 203
 204         (struct usb_descriptor_header *)&input_terminal_desc,
 205         (struct usb_descriptor_header *)&output_terminal_desc,
 206         (struct usb_descriptor_header *)&feature_unit_desc,
 207
 208         (struct usb_descriptor_header *)&as_interface_alt_0_desc,
 209         (struct usb_descriptor_header *)&as_interface_alt_1_desc,
 210         (struct usb_descriptor_header *)&as_header_desc,
 211
 212         (struct usb_descriptor_header *)&as_type_i_desc,
 213
 214         (struct usb_descriptor_header *)&as_out_ep_desc,
 215         (struct usb_descriptor_header *)&as_iso_out_desc,
 216         NULL,
 217 };
 218
 219 /* string IDs are assigned dynamically */
 220
 221 #define STRING_MANUFACTURER_IDX         0
 222 #define STRING_PRODUCT_IDX              1
 223
 224 static char manufacturer[50];
 225
 226 static struct usb_string strings_dev[] = {
 227         [STRING_MANUFACTURER_IDX].s = manufacturer,
 228         [STRING_PRODUCT_IDX].s = DRIVER_DESC,
 229         {  } /* end of list */
 230 };
 231
 232 static struct usb_gadget_strings stringtab_dev = {
 233         .language       = 0x0409,       /* en-us */
 234         .strings        = strings_dev,
 235 };
 236
 237 static struct usb_gadget_strings *audio_strings[] = {
 238         &stringtab_dev,
 239         NULL,
 240 };
 241
 242 /*
 243  * This function is an ALSA sound card following USB Audio Class Spec 1.0.
 244  */
 245
 246 /*-------------------------------------------------------------------------*/
 247 struct f_audio_buf {
 248         u8 *buf;
 249         int actual;
 250         struct list_head list;
 251 };
 252
 253 static struct f_audio_buf *f_audio_buffer_alloc(int buf_size)
 254 {
 255         struct f_audio_buf *copy_buf;
 256
 257         copy_buf = kzalloc(sizeof *copy_buf, GFP_ATOMIC);
 258         if (!copy_buf)
 259                 return ERR_PTR(-ENOMEM);
 260
 261         copy_buf->buf = kzalloc(buf_size, GFP_ATOMIC);
 262         if (!copy_buf->buf) {
 263                 kfree(copy_buf);
 264                 return ERR_PTR(-ENOMEM);
 265         }
 266
 267         return copy_buf;
 268 }
 269
 270 static void f_audio_buffer_free(struct f_audio_buf *audio_buf)
 271 {
 272         kfree(audio_buf->buf);
 273         kfree(audio_buf);
 274 }
 275 /*-------------------------------------------------------------------------*/
 276
 277 struct f_audio {
 278         struct gaudio                   card;
 279
 280         /* endpoints handle full and/or high speeds */
 281         struct usb_ep                   *out_ep;
 282
 283         spinlock_t                      lock;
 284         struct f_audio_buf *copy_buf;
 285         struct work_struct playback_work;
 286         struct list_head play_queue;
 287
 288         /* Control Set command */
 289         struct list_head cs;
 290         u8 set_cmd;
 291         struct usb_audio_control *set_con;
 292 };
 293
 294 static inline struct f_audio *func_to_audio(struct usb_function *f)
 295 {
 296         return container_of(f, struct f_audio, card.func);
 297 }
 298
 299 /*-------------------------------------------------------------------------*/
 300
 301 static void f_audio_playback_work(struct work_struct *data)
 302 {
 303         struct f_audio *audio = container_of(data, struct f_audio,
 304                                         playback_work);
 305         struct f_audio_buf *play_buf;
 306
 307         spin_lock_irq(&audio->lock);
 308         if (list_empty(&audio->play_queue)) {
 309                 spin_unlock_irq(&audio->lock);
 310                 return;
 311         }
 312         play_buf = list_first_entry(&audio->play_queue,
 313                         struct f_audio_buf, list);
 314         list_del(&play_buf->list);
 315         spin_unlock_irq(&audio->lock);
 316
 317         u_audio_playback(&audio->card, play_buf->buf, play_buf->actual);
 318         f_audio_buffer_free(play_buf);
 319 }
 320
 321 static int f_audio_out_ep_complete(struct usb_ep *ep, struct usb_request *req)
 322 {
 323         struct f_audio *audio = req->context;
 324         struct usb_composite_dev *cdev = audio->card.func.config->cdev;
 325         struct f_audio_buf *copy_buf = audio->copy_buf;
 326         int err;
 327
 328         if (!copy_buf)
 329                 return -EINVAL;
 330
 331         /* Copy buffer is full, add it to the play_queue */
 332         if (audio_buf_size - copy_buf->actual < req->actual) {
 333                 list_add_tail(&copy_buf->list, &audio->play_queue);
 334                 schedule_work(&audio->playback_work);
 335                 copy_buf = f_audio_buffer_alloc(audio_buf_size);
 336                 if (IS_ERR(copy_buf))
 337                         return -ENOMEM;
 338         }
 339
 340         memcpy(copy_buf->buf + copy_buf->actual, req->buf, req->actual);
 341         copy_buf->actual += req->actual;
 342         audio->copy_buf = copy_buf;
 343
 344         err = usb_ep_queue(ep, req, GFP_ATOMIC);
 345         if (err)
 346                 ERROR(cdev, "%s queue req: %d\n", ep->name, err);
 347
 348         return 0;
 349
 350 }
 351
 352 static void f_audio_complete(struct usb_ep *ep, struct usb_request *req)
 353 {
 354         struct f_audio *audio = req->context;
 355         int status = req->status;
 356         u32 data = 0;
 357         struct usb_ep *out_ep = audio->out_ep;
 358
 359         switch (status) {
 360
 361         case 0:                         /* normal completion? */
 362                 if (ep == out_ep)
 363                         f_audio_out_ep_complete(ep, req);
 364                 else if (audio->set_con) {
 365                         memcpy(&data, req->buf, req->length);
 366                         audio->set_con->set(audio->set_con, audio->set_cmd,
 367                                         le16_to_cpu(data));
 368                         audio->set_con = NULL;
 369                 }
 370                 break;
 371         default:
 372                 break;
 373         }
 374 }
 375
 376 static int audio_set_intf_req(struct usb_function *f,
 377                 const struct usb_ctrlrequest *ctrl)
 378 {
 379         struct f_audio          *audio = func_to_audio(f);
 380         struct usb_composite_dev *cdev = f->config->cdev;
 381         struct usb_request      *req = cdev->req;
 382         u8                      id = ((le16_to_cpu(ctrl->wIndex) >> 8) & 0xFF);
 383         u16                     len = le16_to_cpu(ctrl->wLength);
 384         u16                     w_value = le16_to_cpu(ctrl->wValue);
 385         u8                      con_sel = (w_value >> 8) & 0xFF;
 386         u8                      cmd = (ctrl->bRequest & 0x0F);
 387         struct usb_audio_control_selector *cs;
 388         struct usb_audio_control *con;
 389
 390         DBG(cdev, "bRequest 0x%x, w_value 0x%04x, len %d, entity %d\n",
 391                         ctrl->bRequest, w_value, len, id);
 392
 393         list_for_each_entry(cs, &audio->cs, list) {
 394                 if (cs->id == id) {
 395                         list_for_each_entry(con, &cs->control, list) {
 396                                 if (con->type == con_sel) {
 397                                         audio->set_con = con;
 398                                         break;
 399                                 }
 400                         }
 401                         break;
 402                 }
 403         }
 404
 405         audio->set_cmd = cmd;
 406         req->context = audio;
 407         req->complete = f_audio_complete;
 408
 409         return len;
 410 }
 411
 412 static int audio_get_intf_req(struct usb_function *f,
 413                 const struct usb_ctrlrequest *ctrl)
 414 {
 415         struct f_audio          *audio = func_to_audio(f);
 416         struct usb_composite_dev *cdev = f->config->cdev;
 417         struct usb_request      *req = cdev->req;
 418         int                     value = -EOPNOTSUPP;
 419         u8                      id = ((le16_to_cpu(ctrl->wIndex) >> 8) & 0xFF);
 420         u16                     len = le16_to_cpu(ctrl->wLength);
 421         u16                     w_value = le16_to_cpu(ctrl->wValue);
 422         u8                      con_sel = (w_value >> 8) & 0xFF;
 423         u8                      cmd = (ctrl->bRequest & 0x0F);
 424         struct usb_audio_control_selector *cs;
 425         struct usb_audio_control *con;
 426
 427         DBG(cdev, "bRequest 0x%x, w_value 0x%04x, len %d, entity %d\n",
 428                         ctrl->bRequest, w_value, len, id);
 429
 430         list_for_each_entry(cs, &audio->cs, list) {
 431                 if (cs->id == id) {
 432                         list_for_each_entry(con, &cs->control, list) {
 433                                 if (con->type == con_sel && con->get) {
 434                                         value = con->get(con, cmd);
 435                                         break;
 436                                 }
 437                         }
 438                         break;
 439                 }
 440         }
 441
 442         req->context = audio;
 443         req->complete = f_audio_complete;
 444         memcpy(req->buf, &value, len);
 445
 446         return len;
 447 }
 448
 449 static int audio_set_endpoint_req(struct usb_function *f,
 450                 const struct usb_ctrlrequest *ctrl)
 451 {
 452         struct usb_composite_dev *cdev = f->config->cdev;
 453         int                     value = -EOPNOTSUPP;
 454         u16                     ep = le16_to_cpu(ctrl->wIndex);
 455         u16                     len = le16_to_cpu(ctrl->wLength);
 456         u16                     w_value = le16_to_cpu(ctrl->wValue);
 457
 458         DBG(cdev, "bRequest 0x%x, w_value 0x%04x, len %d, endpoint %d\n",
 459                         ctrl->bRequest, w_value, len, ep);
 460
 461         switch (ctrl->bRequest) {
 462         case UAC_SET_CUR:
 463                 value = len;
 464                 break;
 465
 466         case UAC_SET_MIN:
 467                 break;
 468
 469         case UAC_SET_MAX:
 470                 break;
 471
 472         case UAC_SET_RES:
 473                 break;
 474
 475         case UAC_SET_MEM:
 476                 break;
 477
 478         default:
 479                 break;
 480         }
 481
 482         return value;
 483 }
 484
 485 static int audio_get_endpoint_req(struct usb_function *f,
 486                 const struct usb_ctrlrequest *ctrl)
 487 {
 488         struct usb_composite_dev *cdev = f->config->cdev;
 489         int value = -EOPNOTSUPP;
 490         u8 ep = ((le16_to_cpu(ctrl->wIndex) >> 8) & 0xFF);
 491         u16 len = le16_to_cpu(ctrl->wLength);
 492         u16 w_value = le16_to_cpu(ctrl->wValue);
 493
 494         DBG(cdev, "bRequest 0x%x, w_value 0x%04x, len %d, endpoint %d\n",
 495                         ctrl->bRequest, w_value, len, ep);
 496
 497         switch (ctrl->bRequest) {
 498         case UAC_GET_CUR:
 499         case UAC_GET_MIN:
 500         case UAC_GET_MAX:
 501         case UAC_GET_RES:
 502                 value = len;
 503                 break;
 504         case UAC_GET_MEM:
 505                 break;
 506         default:
 507                 break;
 508         }
 509
 510         return value;
 511 }
 512
 513 static int
 514 f_audio_setup(struct usb_function *f, const struct usb_ctrlrequest *ctrl)
 515 {
 516         struct usb_composite_dev *cdev = f->config->cdev;
 517         struct usb_request      *req = cdev->req;
 518         int                     value = -EOPNOTSUPP;
 519         u16                     w_index = le16_to_cpu(ctrl->wIndex);
 520         u16                     w_value = le16_to_cpu(ctrl->wValue);
 521         u16                     w_length = le16_to_cpu(ctrl->wLength);
 522
 523         /* composite driver infrastructure handles everything; interface
 524          * activation uses set_alt().
 525          */
 526         switch (ctrl->bRequestType) {
 527         case USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE:
 528                 value = audio_set_intf_req(f, ctrl);
 529                 break;
 530
 531         case USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE:
 532                 value = audio_get_intf_req(f, ctrl);
 533                 break;
 534
 535         case USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_ENDPOINT:
 536                 value = audio_set_endpoint_req(f, ctrl);
 537                 break;
 538
 539         case USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_ENDPOINT:
 540                 value = audio_get_endpoint_req(f, ctrl);
 541                 break;
 542
 543         default:
 544                 ERROR(cdev, "invalid control req%02x.%02x v%04x i%04x l%d\n",
 545                         ctrl->bRequestType, ctrl->bRequest,
 546                         w_value, w_index, w_length);
 547         }
 548
 549         /* respond with data transfer or status phase? */
 550         if (value >= 0) {
 551                 DBG(cdev, "audio req%02x.%02x v%04x i%04x l%d\n",
 552                         ctrl->bRequestType, ctrl->bRequest,
 553                         w_value, w_index, w_length);
 554                 req->zero = 0;
 555                 req->length = value;
 556                 value = usb_ep_queue(cdev->gadget->ep0, req, GFP_ATOMIC);
 557                 if (value < 0)
 558                         ERROR(cdev, "audio response on err %d\n", value);
 559         }
 560
 561         /* device either stalls (value < 0) or reports success */
 562         return value;
 563 }
 564
 565 static int f_audio_set_alt(struct usb_function *f, unsigned intf, unsigned alt)
 566 {
 567         struct f_audio          *audio = func_to_audio(f);
 568         struct usb_composite_dev *cdev = f->config->cdev;
 569         struct usb_ep *out_ep = audio->out_ep;
 570         struct usb_request *req;
 571         int i = 0, err = 0;
 572
 573         DBG(cdev, "intf %d, alt %d\n", intf, alt);
 574
 575         if (intf == 1) {
 576                 if (alt == 1) {
 577                         usb_ep_enable(out_ep);
 578                         out_ep->driver_data = audio;
 579                         audio->copy_buf = f_audio_buffer_alloc(audio_buf_size);
 580                         if (IS_ERR(audio->copy_buf))
 581                                 return -ENOMEM;
 582
 583                         /*
 584                          * allocate a bunch of read buffers
 585                          * and queue them all at once.
 586                          */
 587                         for (i = 0; i < req_count && err == 0; i++) {
 588                                 req = usb_ep_alloc_request(out_ep, GFP_ATOMIC);
 589                                 if (req) {
 590                                         req->buf = kzalloc(req_buf_size,
 591                                                         GFP_ATOMIC);
 592                                         if (req->buf) {
 593                                                 req->length = req_buf_size;
 594                                                 req->context = audio;
 595                                                 req->complete =
 596                                                         f_audio_complete;
 597                                                 err = usb_ep_queue(out_ep,
 598                                                         req, GFP_ATOMIC);
 599                                                 if (err)
 600                                                         ERROR(cdev,
 601                                                         "%s queue req: %d\n",
 602                                                         out_ep->name, err);
 603                                         } else
 604                                                 err = -ENOMEM;
 605                                 } else
 606                                         err = -ENOMEM;
 607                         }
 608
 609                 } else {
 610                         struct f_audio_buf *copy_buf = audio->copy_buf;
 611                         if (copy_buf) {
 612                                 list_add_tail(&copy_buf->list,
 613                                                 &audio->play_queue);
 614                                 schedule_work(&audio->playback_work);
 615                         }
 616                 }
 617         }
 618
 619         return err;
 620 }
 621
 622 static void f_audio_disable(struct usb_function *f)
 623 {
 624         return;
 625 }
 626
 627 /*-------------------------------------------------------------------------*/
 628
 629 static void f_audio_build_desc(struct f_audio *audio)
 630 {
 631         struct gaudio *card = &audio->card;
 632         u8 *sam_freq;
 633         int rate;
 634
 635         /* Set channel numbers */
 636         input_terminal_desc.bNrChannels = u_audio_get_playback_channels(card);
 637         as_type_i_desc.bNrChannels = u_audio_get_playback_channels(card);
 638
 639         /* Set sample rates */
 640         rate = u_audio_get_playback_rate(card);
 641         sam_freq = as_type_i_desc.tSamFreq[0];
 642         memcpy(sam_freq, &rate, 3);
 643
 644         /* Todo: Set Sample bits and other parameters */
 645
 646         return;
 647 }
 648
 649 /* audio function driver setup/binding */
 650 static int __init
 651 f_audio_bind(struct usb_configuration *c, struct usb_function *f)
 652 {
 653         struct usb_composite_dev *cdev = c->cdev;
 654         struct f_audio          *audio = func_to_audio(f);
 655         int                     status;
 656         struct usb_ep           *ep;
 657
 658         f_audio_build_desc(audio);
 659
 660         /* allocate instance-specific interface IDs, and patch descriptors */
 661         status = usb_interface_id(c, f);
 662         if (status < 0)
 663                 goto fail;
 664         ac_interface_desc.bInterfaceNumber = status;
 665
 666         status = usb_interface_id(c, f);
 667         if (status < 0)
 668                 goto fail;
 669         as_interface_alt_0_desc.bInterfaceNumber = status;
 670         as_interface_alt_1_desc.bInterfaceNumber = status;
 671
 672         status = -ENODEV;
 673
 674         /* allocate instance-specific endpoints */
 675         ep = usb_ep_autoconfig(cdev->gadget, &as_out_ep_desc);
 676         if (!ep)
 677                 goto fail;
 678         audio->out_ep = ep;
 679         audio->out_ep->desc = &as_out_ep_desc;
 680         ep->driver_data = cdev; /* claim */
 681
 682         status = -ENOMEM;
 683
 684         /* copy descriptors, and track endpoint copies */
 685         f->descriptors = usb_copy_descriptors(f_audio_desc);
 686
 687         /*
 688          * support all relevant hardware speeds... we expect that when
 689          * hardware is dual speed, all bulk-capable endpoints work at
 690          * both speeds
 691          */
 692         if (gadget_is_dualspeed(c->cdev->gadget)) {
 693                 c->highspeed = true;
 694                 f->hs_descriptors = usb_copy_descriptors(f_audio_desc);
 695         }
 696
 697         return 0;
 698
 699 fail:
 700
 701         return status;
 702 }
 703
 704 static void
 705 f_audio_unbind(struct usb_configuration *c, struct usb_function *f)
 706 {
 707         struct f_audio          *audio = func_to_audio(f);
 708
 709         usb_free_descriptors(f->descriptors);
 710         usb_free_descriptors(f->hs_descriptors);
 711         kfree(audio);
 712 }
 713
 714 /*-------------------------------------------------------------------------*/
 715
 716 static int generic_set_cmd(struct usb_audio_control *con, u8 cmd, int value)
 717 {
 718         con->data[cmd] = value;
 719
 720         return 0;
 721 }
 722
 723 static int generic_get_cmd(struct usb_audio_control *con, u8 cmd)
 724 {
 725         return con->data[cmd];
 726 }
 727
 728 /* Todo: add more control selecotor dynamically */
 729 int __init control_selector_init(struct f_audio *audio)
 730 {
 731         INIT_LIST_HEAD(&audio->cs);
 732         list_add(&feature_unit.list, &audio->cs);
 733
 734         INIT_LIST_HEAD(&feature_unit.control);
 735         list_add(&mute_control.list, &feature_unit.control);
 736         list_add(&volume_control.list, &feature_unit.control);
 737
 738         volume_control.data[UAC__CUR] = 0xffc0;
 739         volume_control.data[UAC__MIN] = 0xe3a0;
 740         volume_control.data[UAC__MAX] = 0xfff0;
 741         volume_control.data[UAC__RES] = 0x0030;
 742
 743         return 0;
 744 }
 745
 746 /**
 747  * audio_bind_config - add USB audio function to a configuration
 748  * @c: the configuration to supcard the USB audio function
 749  * Context: single threaded during gadget setup
 750  *
 751  * Returns zero on success, else negative errno.
 752  */
 753 int __init audio_bind_config(struct usb_configuration *c)
 754 {
 755         struct f_audio *audio;
 756         int status;
 757
 758         /* allocate and initialize one new instance */
 759         audio = kzalloc(sizeof *audio, GFP_KERNEL);
 760         if (!audio)
 761                 return -ENOMEM;
 762
 763         audio->card.func.name = "g_audio";
 764         audio->card.gadget = c->cdev->gadget;
 765
 766         INIT_LIST_HEAD(&audio->play_queue);
 767         spin_lock_init(&audio->lock);
 768
 769         /* set up ASLA audio devices */
 770         status = gaudio_setup(&audio->card);
 771         if (status < 0)
 772                 goto setup_fail;
 773
 774         audio->card.func.strings = audio_strings;
 775         audio->card.func.bind = f_audio_bind;
 776         audio->card.func.unbind = f_audio_unbind;
 777         audio->card.func.set_alt = f_audio_set_alt;
 778         audio->card.func.setup = f_audio_setup;
 779         audio->card.func.disable = f_audio_disable;
 780
 781         control_selector_init(audio);
 782
 783         INIT_WORK(&audio->playback_work, f_audio_playback_work);
 784
 785         status = usb_add_function(c, &audio->card.func);
 786         if (status)
 787                 goto add_fail;
 788
 789         INFO(c->cdev, "audio_buf_size %d, req_buf_size %d, req_count %d\n",
 790                 audio_buf_size, req_buf_size, req_count);
 791
 792         return status;
 793
 794 add_fail:
 795         gaudio_cleanup();
 796 setup_fail:
 797         kfree(audio);
 798         return status;
 799 }