linux/drivers/usb/gadget/function/f_uac1.c
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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/slab.h>
  13#include <linux/kernel.h>
  14#include <linux/module.h>
  15#include <linux/device.h>
  16#include <linux/atomic.h>
  17
  18#include "u_uac1.h"
  19
  20static int generic_set_cmd(struct usb_audio_control *con, u8 cmd, int value);
  21static int generic_get_cmd(struct usb_audio_control *con, u8 cmd);
  22
  23/*
  24 * DESCRIPTORS ... most are static, but strings and full
  25 * configuration descriptors are built on demand.
  26 */
  27
  28/*
  29 * We have two interfaces- AudioControl and AudioStreaming
  30 * TODO: only supcard playback currently
  31 */
  32#define F_AUDIO_AC_INTERFACE    0
  33#define F_AUDIO_AS_INTERFACE    1
  34#define F_AUDIO_NUM_INTERFACES  1
  35
  36/* B.3.1  Standard AC Interface Descriptor */
  37static struct usb_interface_descriptor ac_interface_desc = {
  38        .bLength =              USB_DT_INTERFACE_SIZE,
  39        .bDescriptorType =      USB_DT_INTERFACE,
  40        .bNumEndpoints =        0,
  41        .bInterfaceClass =      USB_CLASS_AUDIO,
  42        .bInterfaceSubClass =   USB_SUBCLASS_AUDIOCONTROL,
  43};
  44
  45/*
  46 * The number of AudioStreaming and MIDIStreaming interfaces
  47 * in the Audio Interface Collection
  48 */
  49DECLARE_UAC_AC_HEADER_DESCRIPTOR(1);
  50
  51#define UAC_DT_AC_HEADER_LENGTH UAC_DT_AC_HEADER_SIZE(F_AUDIO_NUM_INTERFACES)
  52/* 1 input terminal, 1 output terminal and 1 feature unit */
  53#define UAC_DT_TOTAL_LENGTH (UAC_DT_AC_HEADER_LENGTH + UAC_DT_INPUT_TERMINAL_SIZE \
  54        + UAC_DT_OUTPUT_TERMINAL_SIZE + UAC_DT_FEATURE_UNIT_SIZE(0))
  55/* B.3.2  Class-Specific AC Interface Descriptor */
  56static struct uac1_ac_header_descriptor_1 ac_header_desc = {
  57        .bLength =              UAC_DT_AC_HEADER_LENGTH,
  58        .bDescriptorType =      USB_DT_CS_INTERFACE,
  59        .bDescriptorSubtype =   UAC_HEADER,
  60        .bcdADC =               __constant_cpu_to_le16(0x0100),
  61        .wTotalLength =         __constant_cpu_to_le16(UAC_DT_TOTAL_LENGTH),
  62        .bInCollection =        F_AUDIO_NUM_INTERFACES,
  63        .baInterfaceNr = {
  64        /* Interface number of the first AudioStream interface */
  65                [0] =           1,
  66        }
  67};
  68
  69#define INPUT_TERMINAL_ID       1
  70static struct uac_input_terminal_descriptor input_terminal_desc = {
  71        .bLength =              UAC_DT_INPUT_TERMINAL_SIZE,
  72        .bDescriptorType =      USB_DT_CS_INTERFACE,
  73        .bDescriptorSubtype =   UAC_INPUT_TERMINAL,
  74        .bTerminalID =          INPUT_TERMINAL_ID,
  75        .wTerminalType =        UAC_TERMINAL_STREAMING,
  76        .bAssocTerminal =       0,
  77        .wChannelConfig =       0x3,
  78};
  79
  80DECLARE_UAC_FEATURE_UNIT_DESCRIPTOR(0);
  81
  82#define FEATURE_UNIT_ID         2
  83static struct uac_feature_unit_descriptor_0 feature_unit_desc = {
  84        .bLength                = UAC_DT_FEATURE_UNIT_SIZE(0),
  85        .bDescriptorType        = USB_DT_CS_INTERFACE,
  86        .bDescriptorSubtype     = UAC_FEATURE_UNIT,
  87        .bUnitID                = FEATURE_UNIT_ID,
  88        .bSourceID              = INPUT_TERMINAL_ID,
  89        .bControlSize           = 2,
  90        .bmaControls[0]         = (UAC_FU_MUTE | UAC_FU_VOLUME),
  91};
  92
  93static struct usb_audio_control mute_control = {
  94        .list = LIST_HEAD_INIT(mute_control.list),
  95        .name = "Mute Control",
  96        .type = UAC_FU_MUTE,
  97        /* Todo: add real Mute control code */
  98        .set = generic_set_cmd,
  99        .get = generic_get_cmd,
 100};
 101
 102static struct usb_audio_control volume_control = {
 103        .list = LIST_HEAD_INIT(volume_control.list),
 104        .name = "Volume Control",
 105        .type = UAC_FU_VOLUME,
 106        /* Todo: add real Volume control code */
 107        .set = generic_set_cmd,
 108        .get = generic_get_cmd,
 109};
 110
 111static struct usb_audio_control_selector feature_unit = {
 112        .list = LIST_HEAD_INIT(feature_unit.list),
 113        .id = FEATURE_UNIT_ID,
 114        .name = "Mute & Volume Control",
 115        .type = UAC_FEATURE_UNIT,
 116        .desc = (struct usb_descriptor_header *)&feature_unit_desc,
 117};
 118
 119#define OUTPUT_TERMINAL_ID      3
 120static struct uac1_output_terminal_descriptor output_terminal_desc = {
 121        .bLength                = UAC_DT_OUTPUT_TERMINAL_SIZE,
 122        .bDescriptorType        = USB_DT_CS_INTERFACE,
 123        .bDescriptorSubtype     = UAC_OUTPUT_TERMINAL,
 124        .bTerminalID            = OUTPUT_TERMINAL_ID,
 125        .wTerminalType          = UAC_OUTPUT_TERMINAL_SPEAKER,
 126        .bAssocTerminal         = FEATURE_UNIT_ID,
 127        .bSourceID              = FEATURE_UNIT_ID,
 128};
 129
 130/* B.4.1  Standard AS Interface Descriptor */
 131static struct usb_interface_descriptor as_interface_alt_0_desc = {
 132        .bLength =              USB_DT_INTERFACE_SIZE,
 133        .bDescriptorType =      USB_DT_INTERFACE,
 134        .bAlternateSetting =    0,
 135        .bNumEndpoints =        0,
 136        .bInterfaceClass =      USB_CLASS_AUDIO,
 137        .bInterfaceSubClass =   USB_SUBCLASS_AUDIOSTREAMING,
 138};
 139
 140static struct usb_interface_descriptor as_interface_alt_1_desc = {
 141        .bLength =              USB_DT_INTERFACE_SIZE,
 142        .bDescriptorType =      USB_DT_INTERFACE,
 143        .bAlternateSetting =    1,
 144        .bNumEndpoints =        1,
 145        .bInterfaceClass =      USB_CLASS_AUDIO,
 146        .bInterfaceSubClass =   USB_SUBCLASS_AUDIOSTREAMING,
 147};
 148
 149/* B.4.2  Class-Specific AS Interface Descriptor */
 150static struct uac1_as_header_descriptor as_header_desc = {
 151        .bLength =              UAC_DT_AS_HEADER_SIZE,
 152        .bDescriptorType =      USB_DT_CS_INTERFACE,
 153        .bDescriptorSubtype =   UAC_AS_GENERAL,
 154        .bTerminalLink =        INPUT_TERMINAL_ID,
 155        .bDelay =               1,
 156        .wFormatTag =           UAC_FORMAT_TYPE_I_PCM,
 157};
 158
 159DECLARE_UAC_FORMAT_TYPE_I_DISCRETE_DESC(1);
 160
 161static struct uac_format_type_i_discrete_descriptor_1 as_type_i_desc = {
 162        .bLength =              UAC_FORMAT_TYPE_I_DISCRETE_DESC_SIZE(1),
 163        .bDescriptorType =      USB_DT_CS_INTERFACE,
 164        .bDescriptorSubtype =   UAC_FORMAT_TYPE,
 165        .bFormatType =          UAC_FORMAT_TYPE_I,
 166        .bSubframeSize =        2,
 167        .bBitResolution =       16,
 168        .bSamFreqType =         1,
 169};
 170
 171/* Standard ISO OUT Endpoint Descriptor */
 172static struct usb_endpoint_descriptor as_out_ep_desc  = {
 173        .bLength =              USB_DT_ENDPOINT_AUDIO_SIZE,
 174        .bDescriptorType =      USB_DT_ENDPOINT,
 175        .bEndpointAddress =     USB_DIR_OUT,
 176        .bmAttributes =         USB_ENDPOINT_SYNC_ADAPTIVE
 177                                | USB_ENDPOINT_XFER_ISOC,
 178        .wMaxPacketSize =       cpu_to_le16(UAC1_OUT_EP_MAX_PACKET_SIZE),
 179        .bInterval =            4,
 180};
 181
 182/* Class-specific AS ISO OUT Endpoint Descriptor */
 183static struct uac_iso_endpoint_descriptor as_iso_out_desc = {
 184        .bLength =              UAC_ISO_ENDPOINT_DESC_SIZE,
 185        .bDescriptorType =      USB_DT_CS_ENDPOINT,
 186        .bDescriptorSubtype =   UAC_EP_GENERAL,
 187        .bmAttributes =         1,
 188        .bLockDelayUnits =      1,
 189        .wLockDelay =           __constant_cpu_to_le16(1),
 190};
 191
 192static struct usb_descriptor_header *f_audio_desc[] = {
 193        (struct usb_descriptor_header *)&ac_interface_desc,
 194        (struct usb_descriptor_header *)&ac_header_desc,
 195
 196        (struct usb_descriptor_header *)&input_terminal_desc,
 197        (struct usb_descriptor_header *)&output_terminal_desc,
 198        (struct usb_descriptor_header *)&feature_unit_desc,
 199
 200        (struct usb_descriptor_header *)&as_interface_alt_0_desc,
 201        (struct usb_descriptor_header *)&as_interface_alt_1_desc,
 202        (struct usb_descriptor_header *)&as_header_desc,
 203
 204        (struct usb_descriptor_header *)&as_type_i_desc,
 205
 206        (struct usb_descriptor_header *)&as_out_ep_desc,
 207        (struct usb_descriptor_header *)&as_iso_out_desc,
 208        NULL,
 209};
 210
 211enum {
 212        STR_AC_IF,
 213        STR_INPUT_TERMINAL,
 214        STR_INPUT_TERMINAL_CH_NAMES,
 215        STR_FEAT_DESC_0,
 216        STR_OUTPUT_TERMINAL,
 217        STR_AS_IF_ALT0,
 218        STR_AS_IF_ALT1,
 219};
 220
 221static struct usb_string strings_uac1[] = {
 222        [STR_AC_IF].s = "AC Interface",
 223        [STR_INPUT_TERMINAL].s = "Input terminal",
 224        [STR_INPUT_TERMINAL_CH_NAMES].s = "Channels",
 225        [STR_FEAT_DESC_0].s = "Volume control & mute",
 226        [STR_OUTPUT_TERMINAL].s = "Output terminal",
 227        [STR_AS_IF_ALT0].s = "AS Interface",
 228        [STR_AS_IF_ALT1].s = "AS Interface",
 229        { },
 230};
 231
 232static struct usb_gadget_strings str_uac1 = {
 233        .language = 0x0409,     /* en-us */
 234        .strings = strings_uac1,
 235};
 236
 237static struct usb_gadget_strings *uac1_strings[] = {
 238        &str_uac1,
 239        NULL,
 240};
 241
 242/*
 243 * This function is an ALSA sound card following USB Audio Class Spec 1.0.
 244 */
 245
 246/*-------------------------------------------------------------------------*/
 247struct f_audio_buf {
 248        u8 *buf;
 249        int actual;
 250        struct list_head list;
 251};
 252
 253static 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
 270static void f_audio_buffer_free(struct f_audio_buf *audio_buf)
 271{
 272        kfree(audio_buf->buf);
 273        kfree(audio_buf);
 274}
 275/*-------------------------------------------------------------------------*/
 276
 277struct 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
 294static 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
 301static 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
 321static 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        struct f_uac1_opts *opts;
 327        int audio_buf_size;
 328        int err;
 329
 330        opts = container_of(audio->card.func.fi, struct f_uac1_opts,
 331                            func_inst);
 332        audio_buf_size = opts->audio_buf_size;
 333
 334        if (!copy_buf)
 335                return -EINVAL;
 336
 337        /* Copy buffer is full, add it to the play_queue */
 338        if (audio_buf_size - copy_buf->actual < req->actual) {
 339                list_add_tail(&copy_buf->list, &audio->play_queue);
 340                schedule_work(&audio->playback_work);
 341                copy_buf = f_audio_buffer_alloc(audio_buf_size);
 342                if (IS_ERR(copy_buf))
 343                        return -ENOMEM;
 344        }
 345
 346        memcpy(copy_buf->buf + copy_buf->actual, req->buf, req->actual);
 347        copy_buf->actual += req->actual;
 348        audio->copy_buf = copy_buf;
 349
 350        err = usb_ep_queue(ep, req, GFP_ATOMIC);
 351        if (err)
 352                ERROR(cdev, "%s queue req: %d\n", ep->name, err);
 353
 354        return 0;
 355
 356}
 357
 358static void f_audio_complete(struct usb_ep *ep, struct usb_request *req)
 359{
 360        struct f_audio *audio = req->context;
 361        int status = req->status;
 362        u32 data = 0;
 363        struct usb_ep *out_ep = audio->out_ep;
 364
 365        switch (status) {
 366
 367        case 0:                         /* normal completion? */
 368                if (ep == out_ep)
 369                        f_audio_out_ep_complete(ep, req);
 370                else if (audio->set_con) {
 371                        memcpy(&data, req->buf, req->length);
 372                        audio->set_con->set(audio->set_con, audio->set_cmd,
 373                                        le16_to_cpu(data));
 374                        audio->set_con = NULL;
 375                }
 376                break;
 377        default:
 378                break;
 379        }
 380}
 381
 382static int audio_set_intf_req(struct usb_function *f,
 383                const struct usb_ctrlrequest *ctrl)
 384{
 385        struct f_audio          *audio = func_to_audio(f);
 386        struct usb_composite_dev *cdev = f->config->cdev;
 387        struct usb_request      *req = cdev->req;
 388        u8                      id = ((le16_to_cpu(ctrl->wIndex) >> 8) & 0xFF);
 389        u16                     len = le16_to_cpu(ctrl->wLength);
 390        u16                     w_value = le16_to_cpu(ctrl->wValue);
 391        u8                      con_sel = (w_value >> 8) & 0xFF;
 392        u8                      cmd = (ctrl->bRequest & 0x0F);
 393        struct usb_audio_control_selector *cs;
 394        struct usb_audio_control *con;
 395
 396        DBG(cdev, "bRequest 0x%x, w_value 0x%04x, len %d, entity %d\n",
 397                        ctrl->bRequest, w_value, len, id);
 398
 399        list_for_each_entry(cs, &audio->cs, list) {
 400                if (cs->id == id) {
 401                        list_for_each_entry(con, &cs->control, list) {
 402                                if (con->type == con_sel) {
 403                                        audio->set_con = con;
 404                                        break;
 405                                }
 406                        }
 407                        break;
 408                }
 409        }
 410
 411        audio->set_cmd = cmd;
 412        req->context = audio;
 413        req->complete = f_audio_complete;
 414
 415        return len;
 416}
 417
 418static int audio_get_intf_req(struct usb_function *f,
 419                const struct usb_ctrlrequest *ctrl)
 420{
 421        struct f_audio          *audio = func_to_audio(f);
 422        struct usb_composite_dev *cdev = f->config->cdev;
 423        struct usb_request      *req = cdev->req;
 424        int                     value = -EOPNOTSUPP;
 425        u8                      id = ((le16_to_cpu(ctrl->wIndex) >> 8) & 0xFF);
 426        u16                     len = le16_to_cpu(ctrl->wLength);
 427        u16                     w_value = le16_to_cpu(ctrl->wValue);
 428        u8                      con_sel = (w_value >> 8) & 0xFF;
 429        u8                      cmd = (ctrl->bRequest & 0x0F);
 430        struct usb_audio_control_selector *cs;
 431        struct usb_audio_control *con;
 432
 433        DBG(cdev, "bRequest 0x%x, w_value 0x%04x, len %d, entity %d\n",
 434                        ctrl->bRequest, w_value, len, id);
 435
 436        list_for_each_entry(cs, &audio->cs, list) {
 437                if (cs->id == id) {
 438                        list_for_each_entry(con, &cs->control, list) {
 439                                if (con->type == con_sel && con->get) {
 440                                        value = con->get(con, cmd);
 441                                        break;
 442                                }
 443                        }
 444                        break;
 445                }
 446        }
 447
 448        req->context = audio;
 449        req->complete = f_audio_complete;
 450        len = min_t(size_t, sizeof(value), len);
 451        memcpy(req->buf, &value, len);
 452
 453        return len;
 454}
 455
 456static int audio_set_endpoint_req(struct usb_function *f,
 457                const struct usb_ctrlrequest *ctrl)
 458{
 459        struct usb_composite_dev *cdev = f->config->cdev;
 460        int                     value = -EOPNOTSUPP;
 461        u16                     ep = le16_to_cpu(ctrl->wIndex);
 462        u16                     len = le16_to_cpu(ctrl->wLength);
 463        u16                     w_value = le16_to_cpu(ctrl->wValue);
 464
 465        DBG(cdev, "bRequest 0x%x, w_value 0x%04x, len %d, endpoint %d\n",
 466                        ctrl->bRequest, w_value, len, ep);
 467
 468        switch (ctrl->bRequest) {
 469        case UAC_SET_CUR:
 470                value = len;
 471                break;
 472
 473        case UAC_SET_MIN:
 474                break;
 475
 476        case UAC_SET_MAX:
 477                break;
 478
 479        case UAC_SET_RES:
 480                break;
 481
 482        case UAC_SET_MEM:
 483                break;
 484
 485        default:
 486                break;
 487        }
 488
 489        return value;
 490}
 491
 492static int audio_get_endpoint_req(struct usb_function *f,
 493                const struct usb_ctrlrequest *ctrl)
 494{
 495        struct usb_composite_dev *cdev = f->config->cdev;
 496        int value = -EOPNOTSUPP;
 497        u8 ep = ((le16_to_cpu(ctrl->wIndex) >> 8) & 0xFF);
 498        u16 len = le16_to_cpu(ctrl->wLength);
 499        u16 w_value = le16_to_cpu(ctrl->wValue);
 500
 501        DBG(cdev, "bRequest 0x%x, w_value 0x%04x, len %d, endpoint %d\n",
 502                        ctrl->bRequest, w_value, len, ep);
 503
 504        switch (ctrl->bRequest) {
 505        case UAC_GET_CUR:
 506        case UAC_GET_MIN:
 507        case UAC_GET_MAX:
 508        case UAC_GET_RES:
 509                value = len;
 510                break;
 511        case UAC_GET_MEM:
 512                break;
 513        default:
 514                break;
 515        }
 516
 517        return value;
 518}
 519
 520static int
 521f_audio_setup(struct usb_function *f, const struct usb_ctrlrequest *ctrl)
 522{
 523        struct usb_composite_dev *cdev = f->config->cdev;
 524        struct usb_request      *req = cdev->req;
 525        int                     value = -EOPNOTSUPP;
 526        u16                     w_index = le16_to_cpu(ctrl->wIndex);
 527        u16                     w_value = le16_to_cpu(ctrl->wValue);
 528        u16                     w_length = le16_to_cpu(ctrl->wLength);
 529
 530        /* composite driver infrastructure handles everything; interface
 531         * activation uses set_alt().
 532         */
 533        switch (ctrl->bRequestType) {
 534        case USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE:
 535                value = audio_set_intf_req(f, ctrl);
 536                break;
 537
 538        case USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE:
 539                value = audio_get_intf_req(f, ctrl);
 540                break;
 541
 542        case USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_ENDPOINT:
 543                value = audio_set_endpoint_req(f, ctrl);
 544                break;
 545
 546        case USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_ENDPOINT:
 547                value = audio_get_endpoint_req(f, ctrl);
 548                break;
 549
 550        default:
 551                ERROR(cdev, "invalid control req%02x.%02x v%04x i%04x l%d\n",
 552                        ctrl->bRequestType, ctrl->bRequest,
 553                        w_value, w_index, w_length);
 554        }
 555
 556        /* respond with data transfer or status phase? */
 557        if (value >= 0) {
 558                DBG(cdev, "audio req%02x.%02x v%04x i%04x l%d\n",
 559                        ctrl->bRequestType, ctrl->bRequest,
 560                        w_value, w_index, w_length);
 561                req->zero = 0;
 562                req->length = value;
 563                value = usb_ep_queue(cdev->gadget->ep0, req, GFP_ATOMIC);
 564                if (value < 0)
 565                        ERROR(cdev, "audio response on err %d\n", value);
 566        }
 567
 568        /* device either stalls (value < 0) or reports success */
 569        return value;
 570}
 571
 572static int f_audio_set_alt(struct usb_function *f, unsigned intf, unsigned alt)
 573{
 574        struct f_audio          *audio = func_to_audio(f);
 575        struct usb_composite_dev *cdev = f->config->cdev;
 576        struct usb_ep *out_ep = audio->out_ep;
 577        struct usb_request *req;
 578        struct f_uac1_opts *opts;
 579        int req_buf_size, req_count, audio_buf_size;
 580        int i = 0, err = 0;
 581
 582        DBG(cdev, "intf %d, alt %d\n", intf, alt);
 583
 584        opts = container_of(f->fi, struct f_uac1_opts, func_inst);
 585        req_buf_size = opts->req_buf_size;
 586        req_count = opts->req_count;
 587        audio_buf_size = opts->audio_buf_size;
 588
 589        if (intf == 1) {
 590                if (alt == 1) {
 591                        err = config_ep_by_speed(cdev->gadget, f, out_ep);
 592                        if (err)
 593                                return err;
 594
 595                        usb_ep_enable(out_ep);
 596                        audio->copy_buf = f_audio_buffer_alloc(audio_buf_size);
 597                        if (IS_ERR(audio->copy_buf))
 598                                return -ENOMEM;
 599
 600                        /*
 601                         * allocate a bunch of read buffers
 602                         * and queue them all at once.
 603                         */
 604                        for (i = 0; i < req_count && err == 0; i++) {
 605                                req = usb_ep_alloc_request(out_ep, GFP_ATOMIC);
 606                                if (req) {
 607                                        req->buf = kzalloc(req_buf_size,
 608                                                        GFP_ATOMIC);
 609                                        if (req->buf) {
 610                                                req->length = req_buf_size;
 611                                                req->context = audio;
 612                                                req->complete =
 613                                                        f_audio_complete;
 614                                                err = usb_ep_queue(out_ep,
 615                                                        req, GFP_ATOMIC);
 616                                                if (err)
 617                                                        ERROR(cdev,
 618                                                        "%s queue req: %d\n",
 619                                                        out_ep->name, err);
 620                                        } else
 621                                                err = -ENOMEM;
 622                                } else
 623                                        err = -ENOMEM;
 624                        }
 625
 626                } else {
 627                        struct f_audio_buf *copy_buf = audio->copy_buf;
 628                        if (copy_buf) {
 629                                list_add_tail(&copy_buf->list,
 630                                                &audio->play_queue);
 631                                schedule_work(&audio->playback_work);
 632                        }
 633                }
 634        }
 635
 636        return err;
 637}
 638
 639static void f_audio_disable(struct usb_function *f)
 640{
 641        return;
 642}
 643
 644/*-------------------------------------------------------------------------*/
 645
 646static void f_audio_build_desc(struct f_audio *audio)
 647{
 648        struct gaudio *card = &audio->card;
 649        u8 *sam_freq;
 650        int rate;
 651
 652        /* Set channel numbers */
 653        input_terminal_desc.bNrChannels = u_audio_get_playback_channels(card);
 654        as_type_i_desc.bNrChannels = u_audio_get_playback_channels(card);
 655
 656        /* Set sample rates */
 657        rate = u_audio_get_playback_rate(card);
 658        sam_freq = as_type_i_desc.tSamFreq[0];
 659        memcpy(sam_freq, &rate, 3);
 660
 661        /* Todo: Set Sample bits and other parameters */
 662
 663        return;
 664}
 665
 666/* audio function driver setup/binding */
 667static int
 668f_audio_bind(struct usb_configuration *c, struct usb_function *f)
 669{
 670        struct usb_composite_dev *cdev = c->cdev;
 671        struct f_audio          *audio = func_to_audio(f);
 672        struct usb_string       *us;
 673        int                     status;
 674        struct usb_ep           *ep = NULL;
 675        struct f_uac1_opts      *audio_opts;
 676
 677        audio_opts = container_of(f->fi, struct f_uac1_opts, func_inst);
 678        audio->card.gadget = c->cdev->gadget;
 679        /* set up ASLA audio devices */
 680        if (!audio_opts->bound) {
 681                status = gaudio_setup(&audio->card);
 682                if (status < 0)
 683                        return status;
 684                audio_opts->bound = true;
 685        }
 686        us = usb_gstrings_attach(cdev, uac1_strings, ARRAY_SIZE(strings_uac1));
 687        if (IS_ERR(us))
 688                return PTR_ERR(us);
 689        ac_interface_desc.iInterface = us[STR_AC_IF].id;
 690        input_terminal_desc.iTerminal = us[STR_INPUT_TERMINAL].id;
 691        input_terminal_desc.iChannelNames = us[STR_INPUT_TERMINAL_CH_NAMES].id;
 692        feature_unit_desc.iFeature = us[STR_FEAT_DESC_0].id;
 693        output_terminal_desc.iTerminal = us[STR_OUTPUT_TERMINAL].id;
 694        as_interface_alt_0_desc.iInterface = us[STR_AS_IF_ALT0].id;
 695        as_interface_alt_1_desc.iInterface = us[STR_AS_IF_ALT1].id;
 696
 697
 698        f_audio_build_desc(audio);
 699
 700        /* allocate instance-specific interface IDs, and patch descriptors */
 701        status = usb_interface_id(c, f);
 702        if (status < 0)
 703                goto fail;
 704        ac_interface_desc.bInterfaceNumber = status;
 705
 706        status = usb_interface_id(c, f);
 707        if (status < 0)
 708                goto fail;
 709        as_interface_alt_0_desc.bInterfaceNumber = status;
 710        as_interface_alt_1_desc.bInterfaceNumber = status;
 711
 712        status = -ENODEV;
 713
 714        /* allocate instance-specific endpoints */
 715        ep = usb_ep_autoconfig(cdev->gadget, &as_out_ep_desc);
 716        if (!ep)
 717                goto fail;
 718        audio->out_ep = ep;
 719        audio->out_ep->desc = &as_out_ep_desc;
 720
 721        status = -ENOMEM;
 722
 723        /* copy descriptors, and track endpoint copies */
 724        status = usb_assign_descriptors(f, f_audio_desc, f_audio_desc, NULL,
 725                                        NULL);
 726        if (status)
 727                goto fail;
 728        return 0;
 729
 730fail:
 731        gaudio_cleanup(&audio->card);
 732        return status;
 733}
 734
 735/*-------------------------------------------------------------------------*/
 736
 737static int generic_set_cmd(struct usb_audio_control *con, u8 cmd, int value)
 738{
 739        con->data[cmd] = value;
 740
 741        return 0;
 742}
 743
 744static int generic_get_cmd(struct usb_audio_control *con, u8 cmd)
 745{
 746        return con->data[cmd];
 747}
 748
 749/* Todo: add more control selecotor dynamically */
 750static int control_selector_init(struct f_audio *audio)
 751{
 752        INIT_LIST_HEAD(&audio->cs);
 753        list_add(&feature_unit.list, &audio->cs);
 754
 755        INIT_LIST_HEAD(&feature_unit.control);
 756        list_add(&mute_control.list, &feature_unit.control);
 757        list_add(&volume_control.list, &feature_unit.control);
 758
 759        volume_control.data[UAC__CUR] = 0xffc0;
 760        volume_control.data[UAC__MIN] = 0xe3a0;
 761        volume_control.data[UAC__MAX] = 0xfff0;
 762        volume_control.data[UAC__RES] = 0x0030;
 763
 764        return 0;
 765}
 766
 767static inline struct f_uac1_opts *to_f_uac1_opts(struct config_item *item)
 768{
 769        return container_of(to_config_group(item), struct f_uac1_opts,
 770                            func_inst.group);
 771}
 772
 773static void f_uac1_attr_release(struct config_item *item)
 774{
 775        struct f_uac1_opts *opts = to_f_uac1_opts(item);
 776
 777        usb_put_function_instance(&opts->func_inst);
 778}
 779
 780static struct configfs_item_operations f_uac1_item_ops = {
 781        .release        = f_uac1_attr_release,
 782};
 783
 784#define UAC1_INT_ATTRIBUTE(name)                                        \
 785static ssize_t f_uac1_opts_##name##_show(struct config_item *item,      \
 786                                         char *page)                    \
 787{                                                                       \
 788        struct f_uac1_opts *opts = to_f_uac1_opts(item);                \
 789        int result;                                                     \
 790                                                                        \
 791        mutex_lock(&opts->lock);                                        \
 792        result = sprintf(page, "%u\n", opts->name);                     \
 793        mutex_unlock(&opts->lock);                                      \
 794                                                                        \
 795        return result;                                                  \
 796}                                                                       \
 797                                                                        \
 798static ssize_t f_uac1_opts_##name##_store(struct config_item *item,             \
 799                                          const char *page, size_t len) \
 800{                                                                       \
 801        struct f_uac1_opts *opts = to_f_uac1_opts(item);                \
 802        int ret;                                                        \
 803        u32 num;                                                        \
 804                                                                        \
 805        mutex_lock(&opts->lock);                                        \
 806        if (opts->refcnt) {                                             \
 807                ret = -EBUSY;                                           \
 808                goto end;                                               \
 809        }                                                               \
 810                                                                        \
 811        ret = kstrtou32(page, 0, &num);                                 \
 812        if (ret)                                                        \
 813                goto end;                                               \
 814                                                                        \
 815        opts->name = num;                                               \
 816        ret = len;                                                      \
 817                                                                        \
 818end:                                                                    \
 819        mutex_unlock(&opts->lock);                                      \
 820        return ret;                                                     \
 821}                                                                       \
 822                                                                        \
 823CONFIGFS_ATTR(f_uac1_opts_, name)
 824
 825UAC1_INT_ATTRIBUTE(req_buf_size);
 826UAC1_INT_ATTRIBUTE(req_count);
 827UAC1_INT_ATTRIBUTE(audio_buf_size);
 828
 829#define UAC1_STR_ATTRIBUTE(name)                                        \
 830static ssize_t f_uac1_opts_##name##_show(struct config_item *item,      \
 831                                         char *page)                    \
 832{                                                                       \
 833        struct f_uac1_opts *opts = to_f_uac1_opts(item);                \
 834        int result;                                                     \
 835                                                                        \
 836        mutex_lock(&opts->lock);                                        \
 837        result = sprintf(page, "%s\n", opts->name);                     \
 838        mutex_unlock(&opts->lock);                                      \
 839                                                                        \
 840        return result;                                                  \
 841}                                                                       \
 842                                                                        \
 843static ssize_t f_uac1_opts_##name##_store(struct config_item *item,     \
 844                                          const char *page, size_t len) \
 845{                                                                       \
 846        struct f_uac1_opts *opts = to_f_uac1_opts(item);                \
 847        int ret = -EBUSY;                                               \
 848        char *tmp;                                                      \
 849                                                                        \
 850        mutex_lock(&opts->lock);                                        \
 851        if (opts->refcnt)                                               \
 852                goto end;                                               \
 853                                                                        \
 854        tmp = kstrndup(page, len, GFP_KERNEL);                          \
 855        if (tmp) {                                                      \
 856                ret = -ENOMEM;                                          \
 857                goto end;                                               \
 858        }                                                               \
 859        if (opts->name##_alloc)                                         \
 860                kfree(opts->name);                                      \
 861        opts->name##_alloc = true;                                      \
 862        opts->name = tmp;                                               \
 863        ret = len;                                                      \
 864                                                                        \
 865end:                                                                    \
 866        mutex_unlock(&opts->lock);                                      \
 867        return ret;                                                     \
 868}                                                                       \
 869                                                                        \
 870CONFIGFS_ATTR(f_uac1_opts_, name)
 871
 872UAC1_STR_ATTRIBUTE(fn_play);
 873UAC1_STR_ATTRIBUTE(fn_cap);
 874UAC1_STR_ATTRIBUTE(fn_cntl);
 875
 876static struct configfs_attribute *f_uac1_attrs[] = {
 877        &f_uac1_opts_attr_req_buf_size,
 878        &f_uac1_opts_attr_req_count,
 879        &f_uac1_opts_attr_audio_buf_size,
 880        &f_uac1_opts_attr_fn_play,
 881        &f_uac1_opts_attr_fn_cap,
 882        &f_uac1_opts_attr_fn_cntl,
 883        NULL,
 884};
 885
 886static struct config_item_type f_uac1_func_type = {
 887        .ct_item_ops    = &f_uac1_item_ops,
 888        .ct_attrs       = f_uac1_attrs,
 889        .ct_owner       = THIS_MODULE,
 890};
 891
 892static void f_audio_free_inst(struct usb_function_instance *f)
 893{
 894        struct f_uac1_opts *opts;
 895
 896        opts = container_of(f, struct f_uac1_opts, func_inst);
 897        if (opts->fn_play_alloc)
 898                kfree(opts->fn_play);
 899        if (opts->fn_cap_alloc)
 900                kfree(opts->fn_cap);
 901        if (opts->fn_cntl_alloc)
 902                kfree(opts->fn_cntl);
 903        kfree(opts);
 904}
 905
 906static struct usb_function_instance *f_audio_alloc_inst(void)
 907{
 908        struct f_uac1_opts *opts;
 909
 910        opts = kzalloc(sizeof(*opts), GFP_KERNEL);
 911        if (!opts)
 912                return ERR_PTR(-ENOMEM);
 913
 914        mutex_init(&opts->lock);
 915        opts->func_inst.free_func_inst = f_audio_free_inst;
 916
 917        config_group_init_type_name(&opts->func_inst.group, "",
 918                                    &f_uac1_func_type);
 919
 920        opts->req_buf_size = UAC1_OUT_EP_MAX_PACKET_SIZE;
 921        opts->req_count = UAC1_REQ_COUNT;
 922        opts->audio_buf_size = UAC1_AUDIO_BUF_SIZE;
 923        opts->fn_play = FILE_PCM_PLAYBACK;
 924        opts->fn_cap = FILE_PCM_CAPTURE;
 925        opts->fn_cntl = FILE_CONTROL;
 926        return &opts->func_inst;
 927}
 928
 929static void f_audio_free(struct usb_function *f)
 930{
 931        struct f_audio *audio = func_to_audio(f);
 932        struct f_uac1_opts *opts;
 933
 934        gaudio_cleanup(&audio->card);
 935        opts = container_of(f->fi, struct f_uac1_opts, func_inst);
 936        kfree(audio);
 937        mutex_lock(&opts->lock);
 938        --opts->refcnt;
 939        mutex_unlock(&opts->lock);
 940}
 941
 942static void f_audio_unbind(struct usb_configuration *c, struct usb_function *f)
 943{
 944        usb_free_all_descriptors(f);
 945}
 946
 947static struct usb_function *f_audio_alloc(struct usb_function_instance *fi)
 948{
 949        struct f_audio *audio;
 950        struct f_uac1_opts *opts;
 951
 952        /* allocate and initialize one new instance */
 953        audio = kzalloc(sizeof(*audio), GFP_KERNEL);
 954        if (!audio)
 955                return ERR_PTR(-ENOMEM);
 956
 957        audio->card.func.name = "g_audio";
 958
 959        opts = container_of(fi, struct f_uac1_opts, func_inst);
 960        mutex_lock(&opts->lock);
 961        ++opts->refcnt;
 962        mutex_unlock(&opts->lock);
 963        INIT_LIST_HEAD(&audio->play_queue);
 964        spin_lock_init(&audio->lock);
 965
 966        audio->card.func.bind = f_audio_bind;
 967        audio->card.func.unbind = f_audio_unbind;
 968        audio->card.func.set_alt = f_audio_set_alt;
 969        audio->card.func.setup = f_audio_setup;
 970        audio->card.func.disable = f_audio_disable;
 971        audio->card.func.free_func = f_audio_free;
 972
 973        control_selector_init(audio);
 974
 975        INIT_WORK(&audio->playback_work, f_audio_playback_work);
 976
 977        return &audio->card.func;
 978}
 979
 980DECLARE_USB_FUNCTION_INIT(uac1, f_audio_alloc_inst, f_audio_alloc);
 981MODULE_LICENSE("GPL");
 982MODULE_AUTHOR("Bryan Wu");
 983