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 <asm/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         struct usb_endpoint_descriptor  *out_desc;
 283
 284         spinlock_t                      lock;
 285         struct f_audio_buf *copy_buf;
 286         struct work_struct playback_work;
 287         struct list_head play_queue;
 288
 289         /* Control Set command */
 290         struct list_head cs;
 291         u8 set_cmd;
 292         struct usb_audio_control *set_con;
 293 };
 294
 295 static inline struct f_audio *func_to_audio(struct usb_function *f)
 296 {
 297         return container_of(f, struct f_audio, card.func);
 298 }
 299
 300 /*-------------------------------------------------------------------------*/
 301
 302 static void f_audio_playback_work(struct work_struct *data)
 303 {
 304         struct f_audio *audio = container_of(data, struct f_audio,
 305                                         playback_work);
 306         struct f_audio_buf *play_buf;
 307
 308         spin_lock_irq(&audio->lock);
 309         if (list_empty(&audio->play_queue)) {
 310                 spin_unlock_irq(&audio->lock);
 311                 return;
 312         }
 313         play_buf = list_first_entry(&audio->play_queue,
 314                         struct f_audio_buf, list);
 315         list_del(&play_buf->list);
 316         spin_unlock_irq(&audio->lock);
 317
 318         u_audio_playback(&audio->card, play_buf->buf, play_buf->actual);
 319         f_audio_buffer_free(play_buf);
 320 }
 321
 322 static int f_audio_out_ep_complete(struct usb_ep *ep, struct usb_request *req)
 323 {
 324         struct f_audio *audio = req->context;
 325         struct usb_composite_dev *cdev = audio->card.func.config->cdev;
 326         struct f_audio_buf *copy_buf = audio->copy_buf;
 327         int err;
 328
 329         if (!copy_buf)
 330                 return -EINVAL;
 331
 332         /* Copy buffer is full, add it to the play_queue */
 333         if (audio_buf_size - copy_buf->actual < req->actual) {
 334                 list_add_tail(&copy_buf->list, &audio->play_queue);
 335                 schedule_work(&audio->playback_work);
 336                 copy_buf = f_audio_buffer_alloc(audio_buf_size);
 337                 if (IS_ERR(copy_buf))
 338                         return -ENOMEM;
 339         }
 340
 341         memcpy(copy_buf->buf + copy_buf->actual, req->buf, req->actual);
 342         copy_buf->actual += req->actual;
 343         audio->copy_buf = copy_buf;
 344
 345         err = usb_ep_queue(ep, req, GFP_ATOMIC);
 346         if (err)
 347                 ERROR(cdev, "%s queue req: %d\n", ep->name, err);
 348
 349         return 0;
 350
 351 }
 352
 353 static void f_audio_complete(struct usb_ep *ep, struct usb_request *req)
 354 {
 355         struct f_audio *audio = req->context;
 356         int status = req->status;
 357         u32 data = 0;
 358         struct usb_ep *out_ep = audio->out_ep;
 359
 360         switch (status) {
 361
 362         case 0:                         /* normal completion? */
 363                 if (ep == out_ep)
 364                         f_audio_out_ep_complete(ep, req);
 365                 else if (audio->set_con) {
 366                         memcpy(&data, req->buf, req->length);
 367                         audio->set_con->set(audio->set_con, audio->set_cmd,
 368                                         le16_to_cpu(data));
 369                         audio->set_con = NULL;
 370                 }
 371                 break;
 372         default:
 373                 break;
 374         }
 375 }
 376
 377 static int audio_set_intf_req(struct usb_function *f,
 378                 const struct usb_ctrlrequest *ctrl)
 379 {
 380         struct f_audio          *audio = func_to_audio(f);
 381         struct usb_composite_dev *cdev = f->config->cdev;
 382         struct usb_request      *req = cdev->req;
 383         u8                      id = ((le16_to_cpu(ctrl->wIndex) >> 8) & 0xFF);
 384         u16                     len = le16_to_cpu(ctrl->wLength);
 385         u16                     w_value = le16_to_cpu(ctrl->wValue);
 386         u8                      con_sel = (w_value >> 8) & 0xFF;
 387         u8                      cmd = (ctrl->bRequest & 0x0F);
 388         struct usb_audio_control_selector *cs;
 389         struct usb_audio_control *con;
 390
 391         DBG(cdev, "bRequest 0x%x, w_value 0x%04x, len %d, entity %d\n",
 392                         ctrl->bRequest, w_value, len, id);
 393
 394         list_for_each_entry(cs, &audio->cs, list) {
 395                 if (cs->id == id) {
 396                         list_for_each_entry(con, &cs->control, list) {
 397                                 if (con->type == con_sel) {
 398                                         audio->set_con = con;
 399                                         break;
 400                                 }
 401                         }
 402                         break;
 403                 }
 404         }
 405
 406         audio->set_cmd = cmd;
 407         req->context = audio;
 408         req->complete = f_audio_complete;
 409
 410         return len;
 411 }
 412
 413 static int audio_get_intf_req(struct usb_function *f,
 414                 const struct usb_ctrlrequest *ctrl)
 415 {
 416         struct f_audio          *audio = func_to_audio(f);
 417         struct usb_composite_dev *cdev = f->config->cdev;
 418         struct usb_request      *req = cdev->req;
 419         int                     value = -EOPNOTSUPP;
 420         u8                      id = ((le16_to_cpu(ctrl->wIndex) >> 8) & 0xFF);
 421         u16                     len = le16_to_cpu(ctrl->wLength);
 422         u16                     w_value = le16_to_cpu(ctrl->wValue);
 423         u8                      con_sel = (w_value >> 8) & 0xFF;
 424         u8                      cmd = (ctrl->bRequest & 0x0F);
 425         struct usb_audio_control_selector *cs;
 426         struct usb_audio_control *con;
 427
 428         DBG(cdev, "bRequest 0x%x, w_value 0x%04x, len %d, entity %d\n",
 429                         ctrl->bRequest, w_value, len, id);
 430
 431         list_for_each_entry(cs, &audio->cs, list) {
 432                 if (cs->id == id) {
 433                         list_for_each_entry(con, &cs->control, list) {
 434                                 if (con->type == con_sel && con->get) {
 435                                         value = con->get(con, cmd);
 436                                         break;
 437                                 }
 438                         }
 439                         break;
 440                 }
 441         }
 442
 443         req->context = audio;
 444         req->complete = f_audio_complete;
 445         memcpy(req->buf, &value, len);
 446
 447         return len;
 448 }
 449
 450 static int audio_set_endpoint_req(struct usb_function *f,
 451                 const struct usb_ctrlrequest *ctrl)
 452 {
 453         struct usb_composite_dev *cdev = f->config->cdev;
 454         int                     value = -EOPNOTSUPP;
 455         u16                     ep = le16_to_cpu(ctrl->wIndex);
 456         u16                     len = le16_to_cpu(ctrl->wLength);
 457         u16                     w_value = le16_to_cpu(ctrl->wValue);
 458
 459         DBG(cdev, "bRequest 0x%x, w_value 0x%04x, len %d, endpoint %d\n",
 460                         ctrl->bRequest, w_value, len, ep);
 461
 462         switch (ctrl->bRequest) {
 463         case UAC_SET_CUR:
 464                 value = 0;
 465                 break;
 466
 467         case UAC_SET_MIN:
 468                 break;
 469
 470         case UAC_SET_MAX:
 471                 break;
 472
 473         case UAC_SET_RES:
 474                 break;
 475
 476         case UAC_SET_MEM:
 477                 break;
 478
 479         default:
 480                 break;
 481         }
 482
 483         return value;
 484 }
 485
 486 static int audio_get_endpoint_req(struct usb_function *f,
 487                 const struct usb_ctrlrequest *ctrl)
 488 {
 489         struct usb_composite_dev *cdev = f->config->cdev;
 490         int value = -EOPNOTSUPP;
 491         u8 ep = ((le16_to_cpu(ctrl->wIndex) >> 8) & 0xFF);
 492         u16 len = le16_to_cpu(ctrl->wLength);
 493         u16 w_value = le16_to_cpu(ctrl->wValue);
 494
 495         DBG(cdev, "bRequest 0x%x, w_value 0x%04x, len %d, endpoint %d\n",
 496                         ctrl->bRequest, w_value, len, ep);
 497
 498         switch (ctrl->bRequest) {
 499         case UAC_GET_CUR:
 500         case UAC_GET_MIN:
 501         case UAC_GET_MAX:
 502         case UAC_GET_RES:
 503                 value = 3;
 504                 break;
 505         case UAC_GET_MEM:
 506                 break;
 507         default:
 508                 break;
 509         }
 510
 511         return value;
 512 }
 513
 514 static int
 515 f_audio_setup(struct usb_function *f, const struct usb_ctrlrequest *ctrl)
 516 {
 517         struct usb_composite_dev *cdev = f->config->cdev;
 518         struct usb_request      *req = cdev->req;
 519         int                     value = -EOPNOTSUPP;
 520         u16                     w_index = le16_to_cpu(ctrl->wIndex);
 521         u16                     w_value = le16_to_cpu(ctrl->wValue);
 522         u16                     w_length = le16_to_cpu(ctrl->wLength);
 523
 524         /* composite driver infrastructure handles everything; interface
 525          * activation uses set_alt().
 526          */
 527         switch (ctrl->bRequestType) {
 528         case USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE:
 529                 value = audio_set_intf_req(f, ctrl);
 530                 break;
 531
 532         case USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE:
 533                 value = audio_get_intf_req(f, ctrl);
 534                 break;
 535
 536         case USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_ENDPOINT:
 537                 value = audio_set_endpoint_req(f, ctrl);
 538                 break;
 539
 540         case USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_ENDPOINT:
 541                 value = audio_get_endpoint_req(f, ctrl);
 542                 break;
 543
 544         default:
 545                 ERROR(cdev, "invalid control req%02x.%02x v%04x i%04x l%d\n",
 546                         ctrl->bRequestType, ctrl->bRequest,
 547                         w_value, w_index, w_length);
 548         }
 549
 550         /* respond with data transfer or status phase? */
 551         if (value >= 0) {
 552                 DBG(cdev, "audio req%02x.%02x v%04x i%04x l%d\n",
 553                         ctrl->bRequestType, ctrl->bRequest,
 554                         w_value, w_index, w_length);
 555                 req->zero = 0;
 556                 req->length = value;
 557                 value = usb_ep_queue(cdev->gadget->ep0, req, GFP_ATOMIC);
 558                 if (value < 0)
 559                         ERROR(cdev, "audio response on err %d\n", value);
 560         }
 561
 562         /* device either stalls (value < 0) or reports success */
 563         return value;
 564 }
 565
 566 static int f_audio_set_alt(struct usb_function *f, unsigned intf, unsigned alt)
 567 {
 568         struct f_audio          *audio = func_to_audio(f);
 569         struct usb_composite_dev *cdev = f->config->cdev;
 570         struct usb_ep *out_ep = audio->out_ep;
 571         struct usb_request *req;
 572         int i = 0, err = 0;
 573
 574         DBG(cdev, "intf %d, alt %d\n", intf, alt);
 575
 576         if (intf == 1) {
 577                 if (alt == 1) {
 578                         usb_ep_enable(out_ep, audio->out_desc);
 579                         out_ep->driver_data = audio;
 580                         audio->copy_buf = f_audio_buffer_alloc(audio_buf_size);
 581                         if (IS_ERR(audio->copy_buf))
 582                                 return -ENOMEM;
 583
 584                         /*
 585                          * allocate a bunch of read buffers
 586                          * and queue them all at once.
 587                          */
 588                         for (i = 0; i < req_count && err == 0; i++) {
 589                                 req = usb_ep_alloc_request(out_ep, GFP_ATOMIC);
 590                                 if (req) {
 591                                         req->buf = kzalloc(req_buf_size,
 592                                                         GFP_ATOMIC);
 593                                         if (req->buf) {
 594                                                 req->length = req_buf_size;
 595                                                 req->context = audio;
 596                                                 req->complete =
 597                                                         f_audio_complete;
 598                                                 err = usb_ep_queue(out_ep,
 599                                                         req, GFP_ATOMIC);
 600                                                 if (err)
 601                                                         ERROR(cdev,
 602                                                         "%s queue req: %d\n",
 603                                                         out_ep->name, err);
 604                                         } else
 605                                                 err = -ENOMEM;
 606                                 } else
 607                                         err = -ENOMEM;
 608                         }
 609
 610                 } else {
 611                         struct f_audio_buf *copy_buf = audio->copy_buf;
 612                         if (copy_buf) {
 613                                 list_add_tail(&copy_buf->list,
 614                                                 &audio->play_queue);
 615                                 schedule_work(&audio->playback_work);
 616                         }
 617                 }
 618         }
 619
 620         return err;
 621 }
 622
 623 static void f_audio_disable(struct usb_function *f)
 624 {
 625         return;
 626 }
 627
 628 /*-------------------------------------------------------------------------*/
 629
 630 static void f_audio_build_desc(struct f_audio *audio)
 631 {
 632         struct gaudio *card = &audio->card;
 633         u8 *sam_freq;
 634         int rate;
 635
 636         /* Set channel numbers */
 637         input_terminal_desc.bNrChannels = u_audio_get_playback_channels(card);
 638         as_type_i_desc.bNrChannels = u_audio_get_playback_channels(card);
 639
 640         /* Set sample rates */
 641         rate = u_audio_get_playback_rate(card);
 642         sam_freq = as_type_i_desc.tSamFreq[0];
 643         memcpy(sam_freq, &rate, 3);
 644
 645         /* Todo: Set Sample bits and other parameters */
 646
 647         return;
 648 }
 649
 650 /* audio function driver setup/binding */
 651 static int __init
 652 f_audio_bind(struct usb_configuration *c, struct usb_function *f)
 653 {
 654         struct usb_composite_dev *cdev = c->cdev;
 655         struct f_audio          *audio = func_to_audio(f);
 656         int                     status;
 657         struct usb_ep           *ep;
 658
 659         f_audio_build_desc(audio);
 660
 661         /* allocate instance-specific interface IDs, and patch descriptors */
 662         status = usb_interface_id(c, f);
 663         if (status < 0)
 664                 goto fail;
 665         ac_interface_desc.bInterfaceNumber = status;
 666
 667         status = usb_interface_id(c, f);
 668         if (status < 0)
 669                 goto fail;
 670         as_interface_alt_0_desc.bInterfaceNumber = status;
 671         as_interface_alt_1_desc.bInterfaceNumber = status;
 672
 673         status = -ENODEV;
 674
 675         /* allocate instance-specific endpoints */
 676         ep = usb_ep_autoconfig(cdev->gadget, &as_out_ep_desc);
 677         if (!ep)
 678                 goto fail;
 679         audio->out_ep = ep;
 680         ep->driver_data = cdev; /* claim */
 681
 682         status = -ENOMEM;
 683
 684         /* supcard all relevant hardware speeds... we expect that when
 685          * hardware is dual speed, all bulk-capable endpoints work at
 686          * both speeds
 687          */
 688
 689         /* copy descriptors, and track endpoint copies */
 690         if (gadget_is_dualspeed(c->cdev->gadget)) {
 691                 c->highspeed = true;
 692                 f->hs_descriptors = usb_copy_descriptors(f_audio_desc);
 693         } else
 694                 f->descriptors = usb_copy_descriptors(f_audio_desc);
 695
 696         return 0;
 697
 698 fail:
 699
 700         return status;
 701 }
 702
 703 static void
 704 f_audio_unbind(struct usb_configuration *c, struct usb_function *f)
 705 {
 706         struct f_audio          *audio = func_to_audio(f);
 707
 708         usb_free_descriptors(f->descriptors);
 709         usb_free_descriptors(f->hs_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 function 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();
 796 setup_fail:
 797         kfree(audio);
 798         return status;
 799 }