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   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 /* 1 input terminal, 1 output terminal and 1 feature unit */
  60 #define UAC_DT_TOTAL_LENGTH (UAC_DT_AC_HEADER_LENGTH + UAC_DT_INPUT_TERMINAL_SIZE \
  61         + UAC_DT_OUTPUT_TERMINAL_SIZE + UAC_DT_FEATURE_UNIT_SIZE(0))
  62 /* B.3.2  Class-Specific AC Interface Descriptor */
  63 static struct uac_ac_header_descriptor_2 ac_header_desc = {
  64         .bLength =              UAC_DT_AC_HEADER_LENGTH,
  65         .bDescriptorType =      USB_DT_CS_INTERFACE,
  66         .bDescriptorSubtype =   UAC_HEADER,
  67         .bcdADC =               __constant_cpu_to_le16(0x0100),
  68         .wTotalLength =         __constant_cpu_to_le16(UAC_DT_TOTAL_LENGTH),
  69         .bInCollection =        F_AUDIO_NUM_INTERFACES,
  70         .baInterfaceNr = {
  71                 [0] =           F_AUDIO_AC_INTERFACE,
  72                 [1] =           F_AUDIO_AS_INTERFACE,
  73         }
  74 };
  75
  76 #define INPUT_TERMINAL_ID       1
  77 static struct uac_input_terminal_descriptor input_terminal_desc = {
  78         .bLength =              UAC_DT_INPUT_TERMINAL_SIZE,
  79         .bDescriptorType =      USB_DT_CS_INTERFACE,
  80         .bDescriptorSubtype =   UAC_INPUT_TERMINAL,
  81         .bTerminalID =          INPUT_TERMINAL_ID,
  82         .wTerminalType =        UAC_TERMINAL_STREAMING,
  83         .bAssocTerminal =       0,
  84         .wChannelConfig =       0x3,
  85 };
  86
  87 DECLARE_UAC_FEATURE_UNIT_DESCRIPTOR(0);
  88
  89 #define FEATURE_UNIT_ID         2
  90 static struct uac_feature_unit_descriptor_0 feature_unit_desc = {
  91         .bLength                = UAC_DT_FEATURE_UNIT_SIZE(0),
  92         .bDescriptorType        = USB_DT_CS_INTERFACE,
  93         .bDescriptorSubtype     = UAC_FEATURE_UNIT,
  94         .bUnitID                = FEATURE_UNIT_ID,
  95         .bSourceID              = INPUT_TERMINAL_ID,
  96         .bControlSize           = 2,
  97         .bmaControls[0]         = (UAC_FU_MUTE | UAC_FU_VOLUME),
  98 };
  99
 100 static struct usb_audio_control mute_control = {
 101         .list = LIST_HEAD_INIT(mute_control.list),
 102         .name = "Mute Control",
 103         .type = UAC_MUTE_CONTROL,
 104         /* Todo: add real Mute control code */
 105         .set = generic_set_cmd,
 106         .get = generic_get_cmd,
 107 };
 108
 109 static struct usb_audio_control volume_control = {
 110         .list = LIST_HEAD_INIT(volume_control.list),
 111         .name = "Volume Control",
 112         .type = UAC_VOLUME_CONTROL,
 113         /* Todo: add real Volume control code */
 114         .set = generic_set_cmd,
 115         .get = generic_get_cmd,
 116 };
 117
 118 static struct usb_audio_control_selector feature_unit = {
 119         .list = LIST_HEAD_INIT(feature_unit.list),
 120         .id = FEATURE_UNIT_ID,
 121         .name = "Mute & Volume Control",
 122         .type = UAC_FEATURE_UNIT,
 123         .desc = (struct usb_descriptor_header *)&feature_unit_desc,
 124 };
 125
 126 #define OUTPUT_TERMINAL_ID      3
 127 static struct uac_output_terminal_descriptor output_terminal_desc = {
 128         .bLength                = UAC_DT_OUTPUT_TERMINAL_SIZE,
 129         .bDescriptorType        = USB_DT_CS_INTERFACE,
 130         .bDescriptorSubtype     = UAC_OUTPUT_TERMINAL,
 131         .bTerminalID            = OUTPUT_TERMINAL_ID,
 132         .wTerminalType          = UAC_OUTPUT_TERMINAL_SPEAKER,
 133         .bAssocTerminal         = FEATURE_UNIT_ID,
 134         .bSourceID              = FEATURE_UNIT_ID,
 135 };
 136
 137 /* B.4.1  Standard AS Interface Descriptor */
 138 static struct usb_interface_descriptor as_interface_alt_0_desc = {
 139         .bLength =              USB_DT_INTERFACE_SIZE,
 140         .bDescriptorType =      USB_DT_INTERFACE,
 141         .bAlternateSetting =    0,
 142         .bNumEndpoints =        0,
 143         .bInterfaceClass =      USB_CLASS_AUDIO,
 144         .bInterfaceSubClass =   USB_SUBCLASS_AUDIOSTREAMING,
 145 };
 146
 147 static struct usb_interface_descriptor as_interface_alt_1_desc = {
 148         .bLength =              USB_DT_INTERFACE_SIZE,
 149         .bDescriptorType =      USB_DT_INTERFACE,
 150         .bAlternateSetting =    1,
 151         .bNumEndpoints =        1,
 152         .bInterfaceClass =      USB_CLASS_AUDIO,
 153         .bInterfaceSubClass =   USB_SUBCLASS_AUDIOSTREAMING,
 154 };
 155
 156 /* B.4.2  Class-Specific AS Interface Descriptor */
 157 static struct uac_as_header_descriptor as_header_desc = {
 158         .bLength =              UAC_DT_AS_HEADER_SIZE,
 159         .bDescriptorType =      USB_DT_CS_INTERFACE,
 160         .bDescriptorSubtype =   UAC_AS_GENERAL,
 161         .bTerminalLink =        INPUT_TERMINAL_ID,
 162         .bDelay =               1,
 163         .wFormatTag =           UAC_FORMAT_TYPE_I_PCM,
 164 };
 165
 166 DECLARE_UAC_FORMAT_TYPE_I_DISCRETE_DESC(1);
 167
 168 static struct uac_format_type_i_discrete_descriptor_1 as_type_i_desc = {
 169         .bLength =              UAC_FORMAT_TYPE_I_DISCRETE_DESC_SIZE(1),
 170         .bDescriptorType =      USB_DT_CS_INTERFACE,
 171         .bDescriptorSubtype =   UAC_FORMAT_TYPE,
 172         .bFormatType =          UAC_FORMAT_TYPE_I,
 173         .bSubframeSize =        2,
 174         .bBitResolution =       16,
 175         .bSamFreqType =         1,
 176 };
 177
 178 /* Standard ISO OUT Endpoint Descriptor */
 179 static struct usb_endpoint_descriptor as_out_ep_desc __initdata = {
 180         .bLength =              USB_DT_ENDPOINT_AUDIO_SIZE,
 181         .bDescriptorType =      USB_DT_ENDPOINT,
 182         .bEndpointAddress =     USB_DIR_OUT,
 183         .bmAttributes =         USB_ENDPOINT_SYNC_ADAPTIVE
 184                                 | USB_ENDPOINT_XFER_ISOC,
 185         .wMaxPacketSize =       __constant_cpu_to_le16(OUT_EP_MAX_PACKET_SIZE),
 186         .bInterval =            4,
 187 };
 188
 189 /* Class-specific AS ISO OUT Endpoint Descriptor */
 190 static struct uac_iso_endpoint_descriptor as_iso_out_desc __initdata = {
 191         .bLength =              UAC_ISO_ENDPOINT_DESC_SIZE,
 192         .bDescriptorType =      USB_DT_CS_ENDPOINT,
 193         .bDescriptorSubtype =   UAC_EP_GENERAL,
 194         .bmAttributes =         1,
 195         .bLockDelayUnits =      1,
 196         .wLockDelay =           __constant_cpu_to_le16(1),
 197 };
 198
 199 static struct usb_descriptor_header *f_audio_desc[] __initdata = {
 200         (struct usb_descriptor_header *)&ac_interface_desc,
 201         (struct usb_descriptor_header *)&ac_header_desc,
 202
 203         (struct usb_descriptor_header *)&input_terminal_desc,
 204         (struct usb_descriptor_header *)&output_terminal_desc,
 205         (struct usb_descriptor_header *)&feature_unit_desc,
 206
 207         (struct usb_descriptor_header *)&as_interface_alt_0_desc,
 208         (struct usb_descriptor_header *)&as_interface_alt_1_desc,
 209         (struct usb_descriptor_header *)&as_header_desc,
 210
 211         (struct usb_descriptor_header *)&as_type_i_desc,
 212
 213         (struct usb_descriptor_header *)&as_out_ep_desc,
 214         (struct usb_descriptor_header *)&as_iso_out_desc,
 215         NULL,
 216 };
 217
 218 /* string IDs are assigned dynamically */
 219
 220 #define STRING_MANUFACTURER_IDX         0
 221 #define STRING_PRODUCT_IDX              1
 222
 223 static char manufacturer[50];
 224
 225 static struct usb_string strings_dev[] = {
 226         [STRING_MANUFACTURER_IDX].s = manufacturer,
 227         [STRING_PRODUCT_IDX].s = DRIVER_DESC,
 228         {  } /* end of list */
 229 };
 230
 231 static struct usb_gadget_strings stringtab_dev = {
 232         .language       = 0x0409,       /* en-us */
 233         .strings        = strings_dev,
 234 };
 235
 236 static struct usb_gadget_strings *audio_strings[] = {
 237         &stringtab_dev,
 238         NULL,
 239 };
 240
 241 /*
 242  * This function is an ALSA sound card following USB Audio Class Spec 1.0.
 243  */
 244
 245 /*-------------------------------------------------------------------------*/
 246 struct f_audio_buf {
 247         u8 *buf;
 248         int actual;
 249         struct list_head list;
 250 };
 251
 252 static struct f_audio_buf *f_audio_buffer_alloc(int buf_size)
 253 {
 254         struct f_audio_buf *copy_buf;
 255
 256         copy_buf = kzalloc(sizeof *copy_buf, GFP_ATOMIC);
 257         if (!copy_buf)
 258                 return ERR_PTR(-ENOMEM);
 259
 260         copy_buf->buf = kzalloc(buf_size, GFP_ATOMIC);
 261         if (!copy_buf->buf) {
 262                 kfree(copy_buf);
 263                 return ERR_PTR(-ENOMEM);
 264         }
 265
 266         return copy_buf;
 267 }
 268
 269 static void f_audio_buffer_free(struct f_audio_buf *audio_buf)
 270 {
 271         kfree(audio_buf->buf);
 272         kfree(audio_buf);
 273 }
 274 /*-------------------------------------------------------------------------*/
 275
 276 struct f_audio {
 277         struct gaudio                   card;
 278
 279         /* endpoints handle full and/or high speeds */
 280         struct usb_ep                   *out_ep;
 281         struct usb_endpoint_descriptor  *out_desc;
 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         return;
 321 }
 322
 323 static int f_audio_out_ep_complete(struct usb_ep *ep, struct usb_request *req)
 324 {
 325         struct f_audio *audio = req->context;
 326         struct usb_composite_dev *cdev = audio->card.func.config->cdev;
 327         struct f_audio_buf *copy_buf = audio->copy_buf;
 328         int err;
 329
 330         if (!copy_buf)
 331                 return -EINVAL;
 332
 333         /* Copy buffer is full, add it to the play_queue */
 334         if (audio_buf_size - copy_buf->actual < req->actual) {
 335                 list_add_tail(&copy_buf->list, &audio->play_queue);
 336                 schedule_work(&audio->playback_work);
 337                 copy_buf = f_audio_buffer_alloc(audio_buf_size);
 338                 if (IS_ERR(copy_buf))
 339                         return -ENOMEM;
 340         }
 341
 342         memcpy(copy_buf->buf + copy_buf->actual, req->buf, req->actual);
 343         copy_buf->actual += req->actual;
 344         audio->copy_buf = copy_buf;
 345
 346         err = usb_ep_queue(ep, req, GFP_ATOMIC);
 347         if (err)
 348                 ERROR(cdev, "%s queue req: %d\n", ep->name, err);
 349
 350         return 0;
 351
 352 }
 353
 354 static void f_audio_complete(struct usb_ep *ep, struct usb_request *req)
 355 {
 356         struct f_audio *audio = req->context;
 357         int status = req->status;
 358         u32 data = 0;
 359         struct usb_ep *out_ep = audio->out_ep;
 360
 361         switch (status) {
 362
 363         case 0:                         /* normal completion? */
 364                 if (ep == out_ep)
 365                         f_audio_out_ep_complete(ep, req);
 366                 else if (audio->set_con) {
 367                         memcpy(&data, req->buf, req->length);
 368                         audio->set_con->set(audio->set_con, audio->set_cmd,
 369                                         le16_to_cpu(data));
 370                         audio->set_con = NULL;
 371                 }
 372                 break;
 373         default:
 374                 break;
 375         }
 376 }
 377
 378 static int audio_set_intf_req(struct usb_function *f,
 379                 const struct usb_ctrlrequest *ctrl)
 380 {
 381         struct f_audio          *audio = func_to_audio(f);
 382         struct usb_composite_dev *cdev = f->config->cdev;
 383         struct usb_request      *req = cdev->req;
 384         u8                      id = ((le16_to_cpu(ctrl->wIndex) >> 8) & 0xFF);
 385         u16                     len = le16_to_cpu(ctrl->wLength);
 386         u16                     w_value = le16_to_cpu(ctrl->wValue);
 387         u8                      con_sel = (w_value >> 8) & 0xFF;
 388         u8                      cmd = (ctrl->bRequest & 0x0F);
 389         struct usb_audio_control_selector *cs;
 390         struct usb_audio_control *con;
 391
 392         DBG(cdev, "bRequest 0x%x, w_value 0x%04x, len %d, entity %d\n",
 393                         ctrl->bRequest, w_value, len, id);
 394
 395         list_for_each_entry(cs, &audio->cs, list) {
 396                 if (cs->id == id) {
 397                         list_for_each_entry(con, &cs->control, list) {
 398                                 if (con->type == con_sel) {
 399                                         audio->set_con = con;
 400                                         break;
 401                                 }
 402                         }
 403                         break;
 404                 }
 405         }
 406
 407         audio->set_cmd = cmd;
 408         req->context = audio;
 409         req->complete = f_audio_complete;
 410
 411         return len;
 412 }
 413
 414 static int audio_get_intf_req(struct usb_function *f,
 415                 const struct usb_ctrlrequest *ctrl)
 416 {
 417         struct f_audio          *audio = func_to_audio(f);
 418         struct usb_composite_dev *cdev = f->config->cdev;
 419         struct usb_request      *req = cdev->req;
 420         int                     value = -EOPNOTSUPP;
 421         u8                      id = ((le16_to_cpu(ctrl->wIndex) >> 8) & 0xFF);
 422         u16                     len = le16_to_cpu(ctrl->wLength);
 423         u16                     w_value = le16_to_cpu(ctrl->wValue);
 424         u8                      con_sel = (w_value >> 8) & 0xFF;
 425         u8                      cmd = (ctrl->bRequest & 0x0F);
 426         struct usb_audio_control_selector *cs;
 427         struct usb_audio_control *con;
 428
 429         DBG(cdev, "bRequest 0x%x, w_value 0x%04x, len %d, entity %d\n",
 430                         ctrl->bRequest, w_value, len, id);
 431
 432         list_for_each_entry(cs, &audio->cs, list) {
 433                 if (cs->id == id) {
 434                         list_for_each_entry(con, &cs->control, list) {
 435                                 if (con->type == con_sel && con->get) {
 436                                         value = con->get(con, cmd);
 437                                         break;
 438                                 }
 439                         }
 440                         break;
 441                 }
 442         }
 443
 444         req->context = audio;
 445         req->complete = f_audio_complete;
 446         memcpy(req->buf, &value, len);
 447
 448         return len;
 449 }
 450
 451 static int audio_set_endpoint_req(struct usb_function *f,
 452                 const struct usb_ctrlrequest *ctrl)
 453 {
 454         struct usb_composite_dev *cdev = f->config->cdev;
 455         int                     value = -EOPNOTSUPP;
 456         u16                     ep = le16_to_cpu(ctrl->wIndex);
 457         u16                     len = le16_to_cpu(ctrl->wLength);
 458         u16                     w_value = le16_to_cpu(ctrl->wValue);
 459
 460         DBG(cdev, "bRequest 0x%x, w_value 0x%04x, len %d, endpoint %d\n",
 461                         ctrl->bRequest, w_value, len, ep);
 462
 463         switch (ctrl->bRequest) {
 464         case UAC_SET_CUR:
 465                 value = 0;
 466                 break;
 467
 468         case UAC_SET_MIN:
 469                 break;
 470
 471         case UAC_SET_MAX:
 472                 break;
 473
 474         case UAC_SET_RES:
 475                 break;
 476
 477         case UAC_SET_MEM:
 478                 break;
 479
 480         default:
 481                 break;
 482         }
 483
 484         return value;
 485 }
 486
 487 static int audio_get_endpoint_req(struct usb_function *f,
 488                 const struct usb_ctrlrequest *ctrl)
 489 {
 490         struct usb_composite_dev *cdev = f->config->cdev;
 491         int value = -EOPNOTSUPP;
 492         u8 ep = ((le16_to_cpu(ctrl->wIndex) >> 8) & 0xFF);
 493         u16 len = le16_to_cpu(ctrl->wLength);
 494         u16 w_value = le16_to_cpu(ctrl->wValue);
 495
 496         DBG(cdev, "bRequest 0x%x, w_value 0x%04x, len %d, endpoint %d\n",
 497                         ctrl->bRequest, w_value, len, ep);
 498
 499         switch (ctrl->bRequest) {
 500         case UAC_GET_CUR:
 501         case UAC_GET_MIN:
 502         case UAC_GET_MAX:
 503         case UAC_GET_RES:
 504                 value = 3;
 505                 break;
 506         case UAC_GET_MEM:
 507                 break;
 508         default:
 509                 break;
 510         }
 511
 512         return value;
 513 }
 514
 515 static int
 516 f_audio_setup(struct usb_function *f, const struct usb_ctrlrequest *ctrl)
 517 {
 518         struct usb_composite_dev *cdev = f->config->cdev;
 519         struct usb_request      *req = cdev->req;
 520         int                     value = -EOPNOTSUPP;
 521         u16                     w_index = le16_to_cpu(ctrl->wIndex);
 522         u16                     w_value = le16_to_cpu(ctrl->wValue);
 523         u16                     w_length = le16_to_cpu(ctrl->wLength);
 524
 525         /* composite driver infrastructure handles everything; interface
 526          * activation uses set_alt().
 527          */
 528         switch (ctrl->bRequestType) {
 529         case USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE:
 530                 value = audio_set_intf_req(f, ctrl);
 531                 break;
 532
 533         case USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE:
 534                 value = audio_get_intf_req(f, ctrl);
 535                 break;
 536
 537         case USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_ENDPOINT:
 538                 value = audio_set_endpoint_req(f, ctrl);
 539                 break;
 540
 541         case USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_ENDPOINT:
 542                 value = audio_get_endpoint_req(f, ctrl);
 543                 break;
 544
 545         default:
 546                 ERROR(cdev, "invalid control req%02x.%02x v%04x i%04x l%d\n",
 547                         ctrl->bRequestType, ctrl->bRequest,
 548                         w_value, w_index, w_length);
 549         }
 550
 551         /* respond with data transfer or status phase? */
 552         if (value >= 0) {
 553                 DBG(cdev, "audio req%02x.%02x v%04x i%04x l%d\n",
 554                         ctrl->bRequestType, ctrl->bRequest,
 555                         w_value, w_index, w_length);
 556                 req->zero = 0;
 557                 req->length = value;
 558                 value = usb_ep_queue(cdev->gadget->ep0, req, GFP_ATOMIC);
 559                 if (value < 0)
 560                         ERROR(cdev, "audio response on err %d\n", value);
 561         }
 562
 563         /* device either stalls (value < 0) or reports success */
 564         return value;
 565 }
 566
 567 static int f_audio_set_alt(struct usb_function *f, unsigned intf, unsigned alt)
 568 {
 569         struct f_audio          *audio = func_to_audio(f);
 570         struct usb_composite_dev *cdev = f->config->cdev;
 571         struct usb_ep *out_ep = audio->out_ep;
 572         struct usb_request *req;
 573         int i = 0, err = 0;
 574
 575         DBG(cdev, "intf %d, alt %d\n", intf, alt);
 576
 577         if (intf == 1) {
 578                 if (alt == 1) {
 579                         usb_ep_enable(out_ep, audio->out_desc);
 580                         out_ep->driver_data = audio;
 581                         audio->copy_buf = f_audio_buffer_alloc(audio_buf_size);
 582                         if (IS_ERR(audio->copy_buf))
 583                                 return -ENOMEM;
 584
 585                         /*
 586                          * allocate a bunch of read buffers
 587                          * and queue them all at once.
 588                          */
 589                         for (i = 0; i < req_count && err == 0; i++) {
 590                                 req = usb_ep_alloc_request(out_ep, GFP_ATOMIC);
 591                                 if (req) {
 592                                         req->buf = kzalloc(req_buf_size,
 593                                                         GFP_ATOMIC);
 594                                         if (req->buf) {
 595                                                 req->length = req_buf_size;
 596                                                 req->context = audio;
 597                                                 req->complete =
 598                                                         f_audio_complete;
 599                                                 err = usb_ep_queue(out_ep,
 600                                                         req, GFP_ATOMIC);
 601                                                 if (err)
 602                                                         ERROR(cdev,
 603                                                         "%s queue req: %d\n",
 604                                                         out_ep->name, err);
 605                                         } else
 606                                                 err = -ENOMEM;
 607                                 } else
 608                                         err = -ENOMEM;
 609                         }
 610
 611                 } else {
 612                         struct f_audio_buf *copy_buf = audio->copy_buf;
 613                         if (copy_buf) {
 614                                 list_add_tail(&copy_buf->list,
 615                                                 &audio->play_queue);
 616                                 schedule_work(&audio->playback_work);
 617                         }
 618                 }
 619         }
 620
 621         return err;
 622 }
 623
 624 static void f_audio_disable(struct usb_function *f)
 625 {
 626         return;
 627 }
 628
 629 /*-------------------------------------------------------------------------*/
 630
 631 static void f_audio_build_desc(struct f_audio *audio)
 632 {
 633         struct gaudio *card = &audio->card;
 634         u8 *sam_freq;
 635         int rate;
 636
 637         /* Set channel numbers */
 638         input_terminal_desc.bNrChannels = u_audio_get_playback_channels(card);
 639         as_type_i_desc.bNrChannels = u_audio_get_playback_channels(card);
 640
 641         /* Set sample rates */
 642         rate = u_audio_get_playback_rate(card);
 643         sam_freq = as_type_i_desc.tSamFreq[0];
 644         memcpy(sam_freq, &rate, 3);
 645
 646         /* Todo: Set Sample bits and other parameters */
 647
 648         return;
 649 }
 650
 651 /* audio function driver setup/binding */
 652 static int __init
 653 f_audio_bind(struct usb_configuration *c, struct usb_function *f)
 654 {
 655         struct usb_composite_dev *cdev = c->cdev;
 656         struct f_audio          *audio = func_to_audio(f);
 657         int                     status;
 658         struct usb_ep           *ep;
 659
 660         f_audio_build_desc(audio);
 661
 662         /* allocate instance-specific interface IDs, and patch descriptors */
 663         status = usb_interface_id(c, f);
 664         if (status < 0)
 665                 goto fail;
 666         ac_interface_desc.bInterfaceNumber = status;
 667
 668         status = usb_interface_id(c, f);
 669         if (status < 0)
 670                 goto fail;
 671         as_interface_alt_0_desc.bInterfaceNumber = status;
 672         as_interface_alt_1_desc.bInterfaceNumber = status;
 673
 674         status = -ENODEV;
 675
 676         /* allocate instance-specific endpoints */
 677         ep = usb_ep_autoconfig(cdev->gadget, &as_out_ep_desc);
 678         if (!ep)
 679                 goto fail;
 680         audio->out_ep = ep;
 681         ep->driver_data = cdev; /* claim */
 682
 683         status = -ENOMEM;
 684
 685         /* supcard all relevant hardware speeds... we expect that when
 686          * hardware is dual speed, all bulk-capable endpoints work at
 687          * both speeds
 688          */
 689
 690         /* copy descriptors, and track endpoint copies */
 691         if (gadget_is_dualspeed(c->cdev->gadget)) {
 692                 c->highspeed = true;
 693                 f->hs_descriptors = usb_copy_descriptors(f_audio_desc);
 694         } else
 695                 f->descriptors = usb_copy_descriptors(f_audio_desc);
 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         kfree(audio);
 711 }
 712
 713 /*-------------------------------------------------------------------------*/
 714
 715 static int generic_set_cmd(struct usb_audio_control *con, u8 cmd, int value)
 716 {
 717         con->data[cmd] = value;
 718
 719         return 0;
 720 }
 721
 722 static int generic_get_cmd(struct usb_audio_control *con, u8 cmd)
 723 {
 724         return con->data[cmd];
 725 }
 726
 727 /* Todo: add more control selecotor dynamically */
 728 int __init control_selector_init(struct f_audio *audio)
 729 {
 730         INIT_LIST_HEAD(&audio->cs);
 731         list_add(&feature_unit.list, &audio->cs);
 732
 733         INIT_LIST_HEAD(&feature_unit.control);
 734         list_add(&mute_control.list, &feature_unit.control);
 735         list_add(&volume_control.list, &feature_unit.control);
 736
 737         volume_control.data[UAC__CUR] = 0xffc0;
 738         volume_control.data[UAC__MIN] = 0xe3a0;
 739         volume_control.data[UAC__MAX] = 0xfff0;
 740         volume_control.data[UAC__RES] = 0x0030;
 741
 742         return 0;
 743 }
 744
 745 /**
 746  * audio_bind_config - add USB audio fucntion to a configuration
 747  * @c: the configuration to supcard the USB audio function
 748  * Context: single threaded during gadget setup
 749  *
 750  * Returns zero on success, else negative errno.
 751  */
 752 int __init audio_bind_config(struct usb_configuration *c)
 753 {
 754         struct f_audio *audio;
 755         int status;
 756
 757         /* allocate and initialize one new instance */
 758         audio = kzalloc(sizeof *audio, GFP_KERNEL);
 759         if (!audio)
 760                 return -ENOMEM;
 761
 762         audio->card.func.name = "g_audio";
 763         audio->card.gadget = c->cdev->gadget;
 764
 765         INIT_LIST_HEAD(&audio->play_queue);
 766         spin_lock_init(&audio->lock);
 767
 768         /* set up ASLA audio devices */
 769         status = gaudio_setup(&audio->card);
 770         if (status < 0)
 771                 goto setup_fail;
 772
 773         audio->card.func.strings = audio_strings;
 774         audio->card.func.bind = f_audio_bind;
 775         audio->card.func.unbind = f_audio_unbind;
 776         audio->card.func.set_alt = f_audio_set_alt;
 777         audio->card.func.setup = f_audio_setup;
 778         audio->card.func.disable = f_audio_disable;
 779         audio->out_desc = &as_out_ep_desc;
 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(&audio->card);
 796 setup_fail:
 797         kfree(audio);
 798         return status;
 799 }