drivers/usb/gadget/function/f_uac1_legacy.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * f_audio.c -- USB Audio class function driver
   4   *
   5  * Copyright (C) 2008 Bryan Wu <cooloney@kernel.org>
   6  * Copyright (C) 2008 Analog Devices, Inc
   7  *
   8  * Enter bugs at http://blackfin.uclinux.org/
   9  */
  10
  11 #include <linux/slab.h>
  12 #include <linux/kernel.h>
  13 #include <linux/module.h>
  14 #include <linux/device.h>
  15 #include <linux/atomic.h>
  16
  17 #include "u_uac1_legacy.h"
  18
  19 static int generic_set_cmd(struct usb_audio_control *con, u8 cmd, int value);
  20 static int generic_get_cmd(struct usb_audio_control *con, u8 cmd);
  21
  22 /*
  23  * DESCRIPTORS ... most are static, but strings and full
  24  * configuration descriptors are built on demand.
  25  */
  26
  27 /*
  28  * We have two interfaces- AudioControl and AudioStreaming
  29  * TODO: only supcard playback currently
  30  */
  31 #define F_AUDIO_AC_INTERFACE    0
  32 #define F_AUDIO_AS_INTERFACE    1
  33 #define F_AUDIO_NUM_INTERFACES  1
  34
  35 /* B.3.1  Standard AC Interface Descriptor */
  36 static struct usb_interface_descriptor ac_interface_desc = {
  37         .bLength =              USB_DT_INTERFACE_SIZE,
  38         .bDescriptorType =      USB_DT_INTERFACE,
  39         .bNumEndpoints =        0,
  40         .bInterfaceClass =      USB_CLASS_AUDIO,
  41         .bInterfaceSubClass =   USB_SUBCLASS_AUDIOCONTROL,
  42 };
  43
  44 /*
  45  * The number of AudioStreaming and MIDIStreaming interfaces
  46  * in the Audio Interface Collection
  47  */
  48 DECLARE_UAC_AC_HEADER_DESCRIPTOR(1);
  49
  50 #define UAC_DT_AC_HEADER_LENGTH UAC_DT_AC_HEADER_SIZE(F_AUDIO_NUM_INTERFACES)
  51 /* 1 input terminal, 1 output terminal and 1 feature unit */
  52 #define UAC_DT_TOTAL_LENGTH (UAC_DT_AC_HEADER_LENGTH + UAC_DT_INPUT_TERMINAL_SIZE \
  53         + UAC_DT_OUTPUT_TERMINAL_SIZE + UAC_DT_FEATURE_UNIT_SIZE(0))
  54 /* B.3.2  Class-Specific AC Interface Descriptor */
  55 static struct uac1_ac_header_descriptor_1 ac_header_desc = {
  56         .bLength =              UAC_DT_AC_HEADER_LENGTH,
  57         .bDescriptorType =      USB_DT_CS_INTERFACE,
  58         .bDescriptorSubtype =   UAC_HEADER,
  59         .bcdADC =               __constant_cpu_to_le16(0x0100),
  60         .wTotalLength =         __constant_cpu_to_le16(UAC_DT_TOTAL_LENGTH),
  61         .bInCollection =        F_AUDIO_NUM_INTERFACES,
  62         .baInterfaceNr = {
  63         /* Interface number of the first AudioStream interface */
  64                 [0] =           1,
  65         }
  66 };
  67
  68 #define INPUT_TERMINAL_ID       1
  69 static struct uac_input_terminal_descriptor input_terminal_desc = {
  70         .bLength =              UAC_DT_INPUT_TERMINAL_SIZE,
  71         .bDescriptorType =      USB_DT_CS_INTERFACE,
  72         .bDescriptorSubtype =   UAC_INPUT_TERMINAL,
  73         .bTerminalID =          INPUT_TERMINAL_ID,
  74         .wTerminalType =        UAC_TERMINAL_STREAMING,
  75         .bAssocTerminal =       0,
  76         .wChannelConfig =       0x3,
  77 };
  78
  79 DECLARE_UAC_FEATURE_UNIT_DESCRIPTOR(0);
  80
  81 #define FEATURE_UNIT_ID         2
  82 static struct uac_feature_unit_descriptor_0 feature_unit_desc = {
  83         .bLength                = UAC_DT_FEATURE_UNIT_SIZE(0),
  84         .bDescriptorType        = USB_DT_CS_INTERFACE,
  85         .bDescriptorSubtype     = UAC_FEATURE_UNIT,
  86         .bUnitID                = FEATURE_UNIT_ID,
  87         .bSourceID              = INPUT_TERMINAL_ID,
  88         .bControlSize           = 2,
  89         .bmaControls[0]         = (UAC_FU_MUTE | UAC_FU_VOLUME),
  90 };
  91
  92 static struct usb_audio_control mute_control = {
  93         .list = LIST_HEAD_INIT(mute_control.list),
  94         .name = "Mute Control",
  95         .type = UAC_FU_MUTE,
  96         /* Todo: add real Mute control code */
  97         .set = generic_set_cmd,
  98         .get = generic_get_cmd,
  99 };
 100
 101 static struct usb_audio_control volume_control = {
 102         .list = LIST_HEAD_INIT(volume_control.list),
 103         .name = "Volume Control",
 104         .type = UAC_FU_VOLUME,
 105         /* Todo: add real Volume control code */
 106         .set = generic_set_cmd,
 107         .get = generic_get_cmd,
 108 };
 109
 110 static struct usb_audio_control_selector feature_unit = {
 111         .list = LIST_HEAD_INIT(feature_unit.list),
 112         .id = FEATURE_UNIT_ID,
 113         .name = "Mute & Volume Control",
 114         .type = UAC_FEATURE_UNIT,
 115         .desc = (struct usb_descriptor_header *)&feature_unit_desc,
 116 };
 117
 118 #define OUTPUT_TERMINAL_ID      3
 119 static struct uac1_output_terminal_descriptor output_terminal_desc = {
 120         .bLength                = UAC_DT_OUTPUT_TERMINAL_SIZE,
 121         .bDescriptorType        = USB_DT_CS_INTERFACE,
 122         .bDescriptorSubtype     = UAC_OUTPUT_TERMINAL,
 123         .bTerminalID            = OUTPUT_TERMINAL_ID,
 124         .wTerminalType          = UAC_OUTPUT_TERMINAL_SPEAKER,
 125         .bAssocTerminal         = FEATURE_UNIT_ID,
 126         .bSourceID              = FEATURE_UNIT_ID,
 127 };
 128
 129 /* B.4.1  Standard AS Interface Descriptor */
 130 static struct usb_interface_descriptor as_interface_alt_0_desc = {
 131         .bLength =              USB_DT_INTERFACE_SIZE,
 132         .bDescriptorType =      USB_DT_INTERFACE,
 133         .bAlternateSetting =    0,
 134         .bNumEndpoints =        0,
 135         .bInterfaceClass =      USB_CLASS_AUDIO,
 136         .bInterfaceSubClass =   USB_SUBCLASS_AUDIOSTREAMING,
 137 };
 138
 139 static struct usb_interface_descriptor as_interface_alt_1_desc = {
 140         .bLength =              USB_DT_INTERFACE_SIZE,
 141         .bDescriptorType =      USB_DT_INTERFACE,
 142         .bAlternateSetting =    1,
 143         .bNumEndpoints =        1,
 144         .bInterfaceClass =      USB_CLASS_AUDIO,
 145         .bInterfaceSubClass =   USB_SUBCLASS_AUDIOSTREAMING,
 146 };
 147
 148 /* B.4.2  Class-Specific AS Interface Descriptor */
 149 static struct uac1_as_header_descriptor as_header_desc = {
 150         .bLength =              UAC_DT_AS_HEADER_SIZE,
 151         .bDescriptorType =      USB_DT_CS_INTERFACE,
 152         .bDescriptorSubtype =   UAC_AS_GENERAL,
 153         .bTerminalLink =        INPUT_TERMINAL_ID,
 154         .bDelay =               1,
 155         .wFormatTag =           UAC_FORMAT_TYPE_I_PCM,
 156 };
 157
 158 DECLARE_UAC_FORMAT_TYPE_I_DISCRETE_DESC(1);
 159
 160 static struct uac_format_type_i_discrete_descriptor_1 as_type_i_desc = {
 161         .bLength =              UAC_FORMAT_TYPE_I_DISCRETE_DESC_SIZE(1),
 162         .bDescriptorType =      USB_DT_CS_INTERFACE,
 163         .bDescriptorSubtype =   UAC_FORMAT_TYPE,
 164         .bFormatType =          UAC_FORMAT_TYPE_I,
 165         .bSubframeSize =        2,
 166         .bBitResolution =       16,
 167         .bSamFreqType =         1,
 168 };
 169
 170 /* Standard ISO OUT Endpoint Descriptor */
 171 static struct usb_endpoint_descriptor as_out_ep_desc  = {
 172         .bLength =              USB_DT_ENDPOINT_AUDIO_SIZE,
 173         .bDescriptorType =      USB_DT_ENDPOINT,
 174         .bEndpointAddress =     USB_DIR_OUT,
 175         .bmAttributes =         USB_ENDPOINT_SYNC_ADAPTIVE
 176                                 | USB_ENDPOINT_XFER_ISOC,
 177         .wMaxPacketSize =       cpu_to_le16(UAC1_OUT_EP_MAX_PACKET_SIZE),
 178         .bInterval =            4,
 179 };
 180
 181 /* Class-specific AS ISO OUT Endpoint Descriptor */
 182 static struct uac_iso_endpoint_descriptor as_iso_out_desc = {
 183         .bLength =              UAC_ISO_ENDPOINT_DESC_SIZE,
 184         .bDescriptorType =      USB_DT_CS_ENDPOINT,
 185         .bDescriptorSubtype =   UAC_EP_GENERAL,
 186         .bmAttributes =         1,
 187         .bLockDelayUnits =      1,
 188         .wLockDelay =           __constant_cpu_to_le16(1),
 189 };
 190
 191 static struct usb_descriptor_header *f_audio_desc[] = {
 192         (struct usb_descriptor_header *)&ac_interface_desc,
 193         (struct usb_descriptor_header *)&ac_header_desc,
 194
 195         (struct usb_descriptor_header *)&input_terminal_desc,
 196         (struct usb_descriptor_header *)&output_terminal_desc,
 197         (struct usb_descriptor_header *)&feature_unit_desc,
 198
 199         (struct usb_descriptor_header *)&as_interface_alt_0_desc,
 200         (struct usb_descriptor_header *)&as_interface_alt_1_desc,
 201         (struct usb_descriptor_header *)&as_header_desc,
 202
 203         (struct usb_descriptor_header *)&as_type_i_desc,
 204
 205         (struct usb_descriptor_header *)&as_out_ep_desc,
 206         (struct usb_descriptor_header *)&as_iso_out_desc,
 207         NULL,
 208 };
 209
 210 enum {
 211         STR_AC_IF,
 212         STR_INPUT_TERMINAL,
 213         STR_INPUT_TERMINAL_CH_NAMES,
 214         STR_FEAT_DESC_0,
 215         STR_OUTPUT_TERMINAL,
 216         STR_AS_IF_ALT0,
 217         STR_AS_IF_ALT1,
 218 };
 219
 220 static struct usb_string strings_uac1[] = {
 221         [STR_AC_IF].s = "AC Interface",
 222         [STR_INPUT_TERMINAL].s = "Input terminal",
 223         [STR_INPUT_TERMINAL_CH_NAMES].s = "Channels",
 224         [STR_FEAT_DESC_0].s = "Volume control & mute",
 225         [STR_OUTPUT_TERMINAL].s = "Output terminal",
 226         [STR_AS_IF_ALT0].s = "AS Interface",
 227         [STR_AS_IF_ALT1].s = "AS Interface",
 228         { },
 229 };
 230
 231 static struct usb_gadget_strings str_uac1 = {
 232         .language = 0x0409,     /* en-us */
 233         .strings = strings_uac1,
 234 };
 235
 236 static struct usb_gadget_strings *uac1_strings[] = {
 237         &str_uac1,
 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         u8 ac_intf, ac_alt;
 280         u8 as_intf, as_alt;
 281
 282         /* endpoints handle full and/or high speeds */
 283         struct usb_ep                   *out_ep;
 284
 285         spinlock_t                      lock;
 286         struct f_audio_buf *copy_buf;
 287         struct work_struct playback_work;
 288         struct list_head play_queue;
 289
 290         /* Control Set command */
 291         struct list_head cs;
 292         u8 set_cmd;
 293         struct usb_audio_control *set_con;
 294 };
 295
 296 static inline struct f_audio *func_to_audio(struct usb_function *f)
 297 {
 298         return container_of(f, struct f_audio, card.func);
 299 }
 300
 301 /*-------------------------------------------------------------------------*/
 302
 303 static void f_audio_playback_work(struct work_struct *data)
 304 {
 305         struct f_audio *audio = container_of(data, struct f_audio,
 306                                         playback_work);
 307         struct f_audio_buf *play_buf;
 308
 309         spin_lock_irq(&audio->lock);
 310         if (list_empty(&audio->play_queue)) {
 311                 spin_unlock_irq(&audio->lock);
 312                 return;
 313         }
 314         play_buf = list_first_entry(&audio->play_queue,
 315                         struct f_audio_buf, list);
 316         list_del(&play_buf->list);
 317         spin_unlock_irq(&audio->lock);
 318
 319         u_audio_playback(&audio->card, play_buf->buf, play_buf->actual);
 320         f_audio_buffer_free(play_buf);
 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         struct f_uac1_legacy_opts *opts;
 329         int audio_buf_size;
 330         int err;
 331
 332         opts = container_of(audio->card.func.fi, struct f_uac1_legacy_opts,
 333                             func_inst);
 334         audio_buf_size = opts->audio_buf_size;
 335
 336         if (!copy_buf)
 337                 return -EINVAL;
 338
 339         /* Copy buffer is full, add it to the play_queue */
 340         if (audio_buf_size - copy_buf->actual < req->actual) {
 341                 list_add_tail(&copy_buf->list, &audio->play_queue);
 342                 schedule_work(&audio->playback_work);
 343                 copy_buf = f_audio_buffer_alloc(audio_buf_size);
 344                 if (IS_ERR(copy_buf))
 345                         return -ENOMEM;
 346         }
 347
 348         memcpy(copy_buf->buf + copy_buf->actual, req->buf, req->actual);
 349         copy_buf->actual += req->actual;
 350         audio->copy_buf = copy_buf;
 351
 352         err = usb_ep_queue(ep, req, GFP_ATOMIC);
 353         if (err)
 354                 ERROR(cdev, "%s queue req: %d\n", ep->name, err);
 355
 356         return 0;
 357
 358 }
 359
 360 static void f_audio_complete(struct usb_ep *ep, struct usb_request *req)
 361 {
 362         struct f_audio *audio = req->context;
 363         int status = req->status;
 364         u32 data = 0;
 365         struct usb_ep *out_ep = audio->out_ep;
 366
 367         switch (status) {
 368
 369         case 0:                         /* normal completion? */
 370                 if (ep == out_ep)
 371                         f_audio_out_ep_complete(ep, req);
 372                 else if (audio->set_con) {
 373                         memcpy(&data, req->buf, req->length);
 374                         audio->set_con->set(audio->set_con, audio->set_cmd,
 375                                         le16_to_cpu(data));
 376                         audio->set_con = NULL;
 377                 }
 378                 break;
 379         default:
 380                 break;
 381         }
 382 }
 383
 384 static int audio_set_intf_req(struct usb_function *f,
 385                 const struct usb_ctrlrequest *ctrl)
 386 {
 387         struct f_audio          *audio = func_to_audio(f);
 388         struct usb_composite_dev *cdev = f->config->cdev;
 389         struct usb_request      *req = cdev->req;
 390         u8                      id = ((le16_to_cpu(ctrl->wIndex) >> 8) & 0xFF);
 391         u16                     len = le16_to_cpu(ctrl->wLength);
 392         u16                     w_value = le16_to_cpu(ctrl->wValue);
 393         u8                      con_sel = (w_value >> 8) & 0xFF;
 394         u8                      cmd = (ctrl->bRequest & 0x0F);
 395         struct usb_audio_control_selector *cs;
 396         struct usb_audio_control *con;
 397
 398         DBG(cdev, "bRequest 0x%x, w_value 0x%04x, len %d, entity %d\n",
 399                         ctrl->bRequest, w_value, len, id);
 400
 401         list_for_each_entry(cs, &audio->cs, list) {
 402                 if (cs->id == id) {
 403                         list_for_each_entry(con, &cs->control, list) {
 404                                 if (con->type == con_sel) {
 405                                         audio->set_con = con;
 406                                         break;
 407                                 }
 408                         }
 409                         break;
 410                 }
 411         }
 412
 413         audio->set_cmd = cmd;
 414         req->context = audio;
 415         req->complete = f_audio_complete;
 416
 417         return len;
 418 }
 419
 420 static int audio_get_intf_req(struct usb_function *f,
 421                 const struct usb_ctrlrequest *ctrl)
 422 {
 423         struct f_audio          *audio = func_to_audio(f);
 424         struct usb_composite_dev *cdev = f->config->cdev;
 425         struct usb_request      *req = cdev->req;
 426         int                     value = -EOPNOTSUPP;
 427         u8                      id = ((le16_to_cpu(ctrl->wIndex) >> 8) & 0xFF);
 428         u16                     len = le16_to_cpu(ctrl->wLength);
 429         u16                     w_value = le16_to_cpu(ctrl->wValue);
 430         u8                      con_sel = (w_value >> 8) & 0xFF;
 431         u8                      cmd = (ctrl->bRequest & 0x0F);
 432         struct usb_audio_control_selector *cs;
 433         struct usb_audio_control *con;
 434
 435         DBG(cdev, "bRequest 0x%x, w_value 0x%04x, len %d, entity %d\n",
 436                         ctrl->bRequest, w_value, len, id);
 437
 438         list_for_each_entry(cs, &audio->cs, list) {
 439                 if (cs->id == id) {
 440                         list_for_each_entry(con, &cs->control, list) {
 441                                 if (con->type == con_sel && con->get) {
 442                                         value = con->get(con, cmd);
 443                                         break;
 444                                 }
 445                         }
 446                         break;
 447                 }
 448         }
 449
 450         req->context = audio;
 451         req->complete = f_audio_complete;
 452         len = min_t(size_t, sizeof(value), len);
 453         memcpy(req->buf, &value, len);
 454
 455         return len;
 456 }
 457
 458 static int audio_set_endpoint_req(struct usb_function *f,
 459                 const struct usb_ctrlrequest *ctrl)
 460 {
 461         struct usb_composite_dev *cdev = f->config->cdev;
 462         int                     value = -EOPNOTSUPP;
 463         u16                     ep = le16_to_cpu(ctrl->wIndex);
 464         u16                     len = le16_to_cpu(ctrl->wLength);
 465         u16                     w_value = le16_to_cpu(ctrl->wValue);
 466
 467         DBG(cdev, "bRequest 0x%x, w_value 0x%04x, len %d, endpoint %d\n",
 468                         ctrl->bRequest, w_value, len, ep);
 469
 470         switch (ctrl->bRequest) {
 471         case UAC_SET_CUR:
 472                 value = len;
 473                 break;
 474
 475         case UAC_SET_MIN:
 476                 break;
 477
 478         case UAC_SET_MAX:
 479                 break;
 480
 481         case UAC_SET_RES:
 482                 break;
 483
 484         case UAC_SET_MEM:
 485                 break;
 486
 487         default:
 488                 break;
 489         }
 490
 491         return value;
 492 }
 493
 494 static int audio_get_endpoint_req(struct usb_function *f,
 495                 const struct usb_ctrlrequest *ctrl)
 496 {
 497         struct usb_composite_dev *cdev = f->config->cdev;
 498         int value = -EOPNOTSUPP;
 499         u8 ep = ((le16_to_cpu(ctrl->wIndex) >> 8) & 0xFF);
 500         u16 len = le16_to_cpu(ctrl->wLength);
 501         u16 w_value = le16_to_cpu(ctrl->wValue);
 502
 503         DBG(cdev, "bRequest 0x%x, w_value 0x%04x, len %d, endpoint %d\n",
 504                         ctrl->bRequest, w_value, len, ep);
 505
 506         switch (ctrl->bRequest) {
 507         case UAC_GET_CUR:
 508         case UAC_GET_MIN:
 509         case UAC_GET_MAX:
 510         case UAC_GET_RES:
 511                 value = len;
 512                 break;
 513         case UAC_GET_MEM:
 514                 break;
 515         default:
 516                 break;
 517         }
 518
 519         return value;
 520 }
 521
 522 static int
 523 f_audio_setup(struct usb_function *f, const struct usb_ctrlrequest *ctrl)
 524 {
 525         struct usb_composite_dev *cdev = f->config->cdev;
 526         struct usb_request      *req = cdev->req;
 527         int                     value = -EOPNOTSUPP;
 528         u16                     w_index = le16_to_cpu(ctrl->wIndex);
 529         u16                     w_value = le16_to_cpu(ctrl->wValue);
 530         u16                     w_length = le16_to_cpu(ctrl->wLength);
 531
 532         /* composite driver infrastructure handles everything; interface
 533          * activation uses set_alt().
 534          */
 535         switch (ctrl->bRequestType) {
 536         case USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE:
 537                 value = audio_set_intf_req(f, ctrl);
 538                 break;
 539
 540         case USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE:
 541                 value = audio_get_intf_req(f, ctrl);
 542                 break;
 543
 544         case USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_ENDPOINT:
 545                 value = audio_set_endpoint_req(f, ctrl);
 546                 break;
 547
 548         case USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_ENDPOINT:
 549                 value = audio_get_endpoint_req(f, ctrl);
 550                 break;
 551
 552         default:
 553                 ERROR(cdev, "invalid control req%02x.%02x v%04x i%04x l%d\n",
 554                         ctrl->bRequestType, ctrl->bRequest,
 555                         w_value, w_index, w_length);
 556         }
 557
 558         /* respond with data transfer or status phase? */
 559         if (value >= 0) {
 560                 DBG(cdev, "audio req%02x.%02x v%04x i%04x l%d\n",
 561                         ctrl->bRequestType, ctrl->bRequest,
 562                         w_value, w_index, w_length);
 563                 req->zero = 0;
 564                 req->length = value;
 565                 value = usb_ep_queue(cdev->gadget->ep0, req, GFP_ATOMIC);
 566                 if (value < 0)
 567                         ERROR(cdev, "audio response on err %d\n", value);
 568         }
 569
 570         /* device either stalls (value < 0) or reports success */
 571         return value;
 572 }
 573
 574 static int f_audio_set_alt(struct usb_function *f, unsigned intf, unsigned alt)
 575 {
 576         struct f_audio          *audio = func_to_audio(f);
 577         struct usb_composite_dev *cdev = f->config->cdev;
 578         struct usb_ep *out_ep = audio->out_ep;
 579         struct usb_request *req;
 580         struct f_uac1_legacy_opts *opts;
 581         int req_buf_size, req_count, audio_buf_size;
 582         int i = 0, err = 0;
 583
 584         DBG(cdev, "intf %d, alt %d\n", intf, alt);
 585
 586         opts = container_of(f->fi, struct f_uac1_legacy_opts, func_inst);
 587         req_buf_size = opts->req_buf_size;
 588         req_count = opts->req_count;
 589         audio_buf_size = opts->audio_buf_size;
 590
 591         /* No i/f has more than 2 alt settings */
 592         if (alt > 1) {
 593                 ERROR(cdev, "%s:%d Error!\n", __func__, __LINE__);
 594                 return -EINVAL;
 595         }
 596
 597         if (intf == audio->ac_intf) {
 598                 /* Control I/f has only 1 AltSetting - 0 */
 599                 if (alt) {
 600                         ERROR(cdev, "%s:%d Error!\n", __func__, __LINE__);
 601                         return -EINVAL;
 602                 }
 603                 return 0;
 604         } else if (intf == audio->as_intf) {
 605                 if (alt == 1) {
 606                         err = config_ep_by_speed(cdev->gadget, f, out_ep);
 607                         if (err)
 608                                 return err;
 609
 610                         usb_ep_enable(out_ep);
 611                         audio->copy_buf = f_audio_buffer_alloc(audio_buf_size);
 612                         if (IS_ERR(audio->copy_buf))
 613                                 return -ENOMEM;
 614
 615                         /*
 616                          * allocate a bunch of read buffers
 617                          * and queue them all at once.
 618                          */
 619                         for (i = 0; i < req_count && err == 0; i++) {
 620                                 req = usb_ep_alloc_request(out_ep, GFP_ATOMIC);
 621                                 if (req) {
 622                                         req->buf = kzalloc(req_buf_size,
 623                                                         GFP_ATOMIC);
 624                                         if (req->buf) {
 625                                                 req->length = req_buf_size;
 626                                                 req->context = audio;
 627                                                 req->complete =
 628                                                         f_audio_complete;
 629                                                 err = usb_ep_queue(out_ep,
 630                                                         req, GFP_ATOMIC);
 631                                                 if (err)
 632                                                         ERROR(cdev,
 633                                                         "%s queue req: %d\n",
 634                                                         out_ep->name, err);
 635                                         } else
 636                                                 err = -ENOMEM;
 637                                 } else
 638                                         err = -ENOMEM;
 639                         }
 640
 641                 } else {
 642                         struct f_audio_buf *copy_buf = audio->copy_buf;
 643                         if (copy_buf) {
 644                                 list_add_tail(&copy_buf->list,
 645                                                 &audio->play_queue);
 646                                 schedule_work(&audio->playback_work);
 647                         }
 648                 }
 649                 audio->as_alt = alt;
 650         }
 651
 652         return err;
 653 }
 654
 655 static int f_audio_get_alt(struct usb_function *f, unsigned intf)
 656 {
 657         struct f_audio          *audio = func_to_audio(f);
 658         struct usb_composite_dev *cdev = f->config->cdev;
 659
 660         if (intf == audio->ac_intf)
 661                 return audio->ac_alt;
 662         else if (intf == audio->as_intf)
 663                 return audio->as_alt;
 664         else
 665                 ERROR(cdev, "%s:%d Invalid Interface %d!\n",
 666                       __func__, __LINE__, intf);
 667
 668         return -EINVAL;
 669 }
 670
 671 static void f_audio_disable(struct usb_function *f)
 672 {
 673         return;
 674 }
 675
 676 /*-------------------------------------------------------------------------*/
 677
 678 static void f_audio_build_desc(struct f_audio *audio)
 679 {
 680         struct gaudio *card = &audio->card;
 681         u8 *sam_freq;
 682         int rate;
 683
 684         /* Set channel numbers */
 685         input_terminal_desc.bNrChannels = u_audio_get_playback_channels(card);
 686         as_type_i_desc.bNrChannels = u_audio_get_playback_channels(card);
 687
 688         /* Set sample rates */
 689         rate = u_audio_get_playback_rate(card);
 690         sam_freq = as_type_i_desc.tSamFreq[0];
 691         memcpy(sam_freq, &rate, 3);
 692
 693         /* Todo: Set Sample bits and other parameters */
 694
 695         return;
 696 }
 697
 698 /* audio function driver setup/binding */
 699 static int
 700 f_audio_bind(struct usb_configuration *c, struct usb_function *f)
 701 {
 702         struct usb_composite_dev *cdev = c->cdev;
 703         struct f_audio          *audio = func_to_audio(f);
 704         struct usb_string       *us;
 705         int                     status;
 706         struct usb_ep           *ep = NULL;
 707         struct f_uac1_legacy_opts       *audio_opts;
 708
 709         audio_opts = container_of(f->fi, struct f_uac1_legacy_opts, func_inst);
 710         audio->card.gadget = c->cdev->gadget;
 711         /* set up ASLA audio devices */
 712         if (!audio_opts->bound) {
 713                 status = gaudio_setup(&audio->card);
 714                 if (status < 0)
 715                         return status;
 716                 audio_opts->bound = true;
 717         }
 718         us = usb_gstrings_attach(cdev, uac1_strings, ARRAY_SIZE(strings_uac1));
 719         if (IS_ERR(us))
 720                 return PTR_ERR(us);
 721         ac_interface_desc.iInterface = us[STR_AC_IF].id;
 722         input_terminal_desc.iTerminal = us[STR_INPUT_TERMINAL].id;
 723         input_terminal_desc.iChannelNames = us[STR_INPUT_TERMINAL_CH_NAMES].id;
 724         feature_unit_desc.iFeature = us[STR_FEAT_DESC_0].id;
 725         output_terminal_desc.iTerminal = us[STR_OUTPUT_TERMINAL].id;
 726         as_interface_alt_0_desc.iInterface = us[STR_AS_IF_ALT0].id;
 727         as_interface_alt_1_desc.iInterface = us[STR_AS_IF_ALT1].id;
 728
 729
 730         f_audio_build_desc(audio);
 731
 732         /* allocate instance-specific interface IDs, and patch descriptors */
 733         status = usb_interface_id(c, f);
 734         if (status < 0)
 735                 goto fail;
 736         ac_interface_desc.bInterfaceNumber = status;
 737         audio->ac_intf = status;
 738         audio->ac_alt = 0;
 739
 740         status = usb_interface_id(c, f);
 741         if (status < 0)
 742                 goto fail;
 743         as_interface_alt_0_desc.bInterfaceNumber = status;
 744         as_interface_alt_1_desc.bInterfaceNumber = status;
 745         audio->as_intf = status;
 746         audio->as_alt = 0;
 747
 748         status = -ENODEV;
 749
 750         /* allocate instance-specific endpoints */
 751         ep = usb_ep_autoconfig(cdev->gadget, &as_out_ep_desc);
 752         if (!ep)
 753                 goto fail;
 754         audio->out_ep = ep;
 755         audio->out_ep->desc = &as_out_ep_desc;
 756
 757         status = -ENOMEM;
 758
 759         /* copy descriptors, and track endpoint copies */
 760         status = usb_assign_descriptors(f, f_audio_desc, f_audio_desc, NULL,
 761                                         NULL);
 762         if (status)
 763                 goto fail;
 764         return 0;
 765
 766 fail:
 767         gaudio_cleanup(&audio->card);
 768         return status;
 769 }
 770
 771 /*-------------------------------------------------------------------------*/
 772
 773 static int generic_set_cmd(struct usb_audio_control *con, u8 cmd, int value)
 774 {
 775         con->data[cmd] = value;
 776
 777         return 0;
 778 }
 779
 780 static int generic_get_cmd(struct usb_audio_control *con, u8 cmd)
 781 {
 782         return con->data[cmd];
 783 }
 784
 785 /* Todo: add more control selecotor dynamically */
 786 static int control_selector_init(struct f_audio *audio)
 787 {
 788         INIT_LIST_HEAD(&audio->cs);
 789         list_add(&feature_unit.list, &audio->cs);
 790
 791         INIT_LIST_HEAD(&feature_unit.control);
 792         list_add(&mute_control.list, &feature_unit.control);
 793         list_add(&volume_control.list, &feature_unit.control);
 794
 795         volume_control.data[UAC__CUR] = 0xffc0;
 796         volume_control.data[UAC__MIN] = 0xe3a0;
 797         volume_control.data[UAC__MAX] = 0xfff0;
 798         volume_control.data[UAC__RES] = 0x0030;
 799
 800         return 0;
 801 }
 802
 803 static inline
 804 struct f_uac1_legacy_opts *to_f_uac1_opts(struct config_item *item)
 805 {
 806         return container_of(to_config_group(item), struct f_uac1_legacy_opts,
 807                             func_inst.group);
 808 }
 809
 810 static void f_uac1_attr_release(struct config_item *item)
 811 {
 812         struct f_uac1_legacy_opts *opts = to_f_uac1_opts(item);
 813
 814         usb_put_function_instance(&opts->func_inst);
 815 }
 816
 817 static struct configfs_item_operations f_uac1_item_ops = {
 818         .release        = f_uac1_attr_release,
 819 };
 820
 821 #define UAC1_INT_ATTRIBUTE(name)                                        \
 822 static ssize_t f_uac1_opts_##name##_show(struct config_item *item,      \
 823                                          char *page)                    \
 824 {                                                                       \
 825         struct f_uac1_legacy_opts *opts = to_f_uac1_opts(item);         \
 826         int result;                                                     \
 827                                                                         \
 828         mutex_lock(&opts->lock);                                        \
 829         result = sprintf(page, "%u\n", opts->name);                     \
 830         mutex_unlock(&opts->lock);                                      \
 831                                                                         \
 832         return result;                                                  \
 833 }                                                                       \
 834                                                                         \
 835 static ssize_t f_uac1_opts_##name##_store(struct config_item *item,             \
 836                                           const char *page, size_t len) \
 837 {                                                                       \
 838         struct f_uac1_legacy_opts *opts = to_f_uac1_opts(item);         \
 839         int ret;                                                        \
 840         u32 num;                                                        \
 841                                                                         \
 842         mutex_lock(&opts->lock);                                        \
 843         if (opts->refcnt) {                                             \
 844                 ret = -EBUSY;                                           \
 845                 goto end;                                               \
 846         }                                                               \
 847                                                                         \
 848         ret = kstrtou32(page, 0, &num);                                 \
 849         if (ret)                                                        \
 850                 goto end;                                               \
 851                                                                         \
 852         opts->name = num;                                               \
 853         ret = len;                                                      \
 854                                                                         \
 855 end:                                                                    \
 856         mutex_unlock(&opts->lock);                                      \
 857         return ret;                                                     \
 858 }                                                                       \
 859                                                                         \
 860 CONFIGFS_ATTR(f_uac1_opts_, name)
 861
 862 UAC1_INT_ATTRIBUTE(req_buf_size);
 863 UAC1_INT_ATTRIBUTE(req_count);
 864 UAC1_INT_ATTRIBUTE(audio_buf_size);
 865
 866 #define UAC1_STR_ATTRIBUTE(name)                                        \
 867 static ssize_t f_uac1_opts_##name##_show(struct config_item *item,      \
 868                                          char *page)                    \
 869 {                                                                       \
 870         struct f_uac1_legacy_opts *opts = to_f_uac1_opts(item);         \
 871         int result;                                                     \
 872                                                                         \
 873         mutex_lock(&opts->lock);                                        \
 874         result = sprintf(page, "%s\n", opts->name);                     \
 875         mutex_unlock(&opts->lock);                                      \
 876                                                                         \
 877         return result;                                                  \
 878 }                                                                       \
 879                                                                         \
 880 static ssize_t f_uac1_opts_##name##_store(struct config_item *item,     \
 881                                           const char *page, size_t len) \
 882 {                                                                       \
 883         struct f_uac1_legacy_opts *opts = to_f_uac1_opts(item);         \
 884         int ret = -EBUSY;                                               \
 885         char *tmp;                                                      \
 886                                                                         \
 887         mutex_lock(&opts->lock);                                        \
 888         if (opts->refcnt)                                               \
 889                 goto end;                                               \
 890                                                                         \
 891         tmp = kstrndup(page, len, GFP_KERNEL);                          \
 892         if (tmp) {                                                      \
 893                 ret = -ENOMEM;                                          \
 894                 goto end;                                               \
 895         }                                                               \
 896         if (opts->name##_alloc)                                         \
 897                 kfree(opts->name);                                      \
 898         opts->name##_alloc = true;                                      \
 899         opts->name = tmp;                                               \
 900         ret = len;                                                      \
 901                                                                         \
 902 end:                                                                    \
 903         mutex_unlock(&opts->lock);                                      \
 904         return ret;                                                     \
 905 }                                                                       \
 906                                                                         \
 907 CONFIGFS_ATTR(f_uac1_opts_, name)
 908
 909 UAC1_STR_ATTRIBUTE(fn_play);
 910 UAC1_STR_ATTRIBUTE(fn_cap);
 911 UAC1_STR_ATTRIBUTE(fn_cntl);
 912
 913 static struct configfs_attribute *f_uac1_attrs[] = {
 914         &f_uac1_opts_attr_req_buf_size,
 915         &f_uac1_opts_attr_req_count,
 916         &f_uac1_opts_attr_audio_buf_size,
 917         &f_uac1_opts_attr_fn_play,
 918         &f_uac1_opts_attr_fn_cap,
 919         &f_uac1_opts_attr_fn_cntl,
 920         NULL,
 921 };
 922
 923 static const struct config_item_type f_uac1_func_type = {
 924         .ct_item_ops    = &f_uac1_item_ops,
 925         .ct_attrs       = f_uac1_attrs,
 926         .ct_owner       = THIS_MODULE,
 927 };
 928
 929 static void f_audio_free_inst(struct usb_function_instance *f)
 930 {
 931         struct f_uac1_legacy_opts *opts;
 932
 933         opts = container_of(f, struct f_uac1_legacy_opts, func_inst);
 934         if (opts->fn_play_alloc)
 935                 kfree(opts->fn_play);
 936         if (opts->fn_cap_alloc)
 937                 kfree(opts->fn_cap);
 938         if (opts->fn_cntl_alloc)
 939                 kfree(opts->fn_cntl);
 940         kfree(opts);
 941 }
 942
 943 static struct usb_function_instance *f_audio_alloc_inst(void)
 944 {
 945         struct f_uac1_legacy_opts *opts;
 946
 947         opts = kzalloc(sizeof(*opts), GFP_KERNEL);
 948         if (!opts)
 949                 return ERR_PTR(-ENOMEM);
 950
 951         mutex_init(&opts->lock);
 952         opts->func_inst.free_func_inst = f_audio_free_inst;
 953
 954         config_group_init_type_name(&opts->func_inst.group, "",
 955                                     &f_uac1_func_type);
 956
 957         opts->req_buf_size = UAC1_OUT_EP_MAX_PACKET_SIZE;
 958         opts->req_count = UAC1_REQ_COUNT;
 959         opts->audio_buf_size = UAC1_AUDIO_BUF_SIZE;
 960         opts->fn_play = FILE_PCM_PLAYBACK;
 961         opts->fn_cap = FILE_PCM_CAPTURE;
 962         opts->fn_cntl = FILE_CONTROL;
 963         return &opts->func_inst;
 964 }
 965
 966 static void f_audio_free(struct usb_function *f)
 967 {
 968         struct f_audio *audio = func_to_audio(f);
 969         struct f_uac1_legacy_opts *opts;
 970
 971         gaudio_cleanup(&audio->card);
 972         opts = container_of(f->fi, struct f_uac1_legacy_opts, func_inst);
 973         kfree(audio);
 974         mutex_lock(&opts->lock);
 975         --opts->refcnt;
 976         mutex_unlock(&opts->lock);
 977 }
 978
 979 static void f_audio_unbind(struct usb_configuration *c, struct usb_function *f)
 980 {
 981         usb_free_all_descriptors(f);
 982 }
 983
 984 static struct usb_function *f_audio_alloc(struct usb_function_instance *fi)
 985 {
 986         struct f_audio *audio;
 987         struct f_uac1_legacy_opts *opts;
 988
 989         /* allocate and initialize one new instance */
 990         audio = kzalloc(sizeof(*audio), GFP_KERNEL);
 991         if (!audio)
 992                 return ERR_PTR(-ENOMEM);
 993
 994         audio->card.func.name = "g_audio";
 995
 996         opts = container_of(fi, struct f_uac1_legacy_opts, func_inst);
 997         mutex_lock(&opts->lock);
 998         ++opts->refcnt;
 999         mutex_unlock(&opts->lock);
1000         INIT_LIST_HEAD(&audio->play_queue);
1001         spin_lock_init(&audio->lock);
1002
1003         audio->card.func.bind = f_audio_bind;
1004         audio->card.func.unbind = f_audio_unbind;
1005         audio->card.func.set_alt = f_audio_set_alt;
1006         audio->card.func.get_alt = f_audio_get_alt;
1007         audio->card.func.setup = f_audio_setup;
1008         audio->card.func.disable = f_audio_disable;
1009         audio->card.func.free_func = f_audio_free;
1010
1011         control_selector_init(audio);
1012
1013         INIT_WORK(&audio->playback_work, f_audio_playback_work);
1014
1015         return &audio->card.func;
1016 }
1017
1018 DECLARE_USB_FUNCTION_INIT(uac1_legacy, f_audio_alloc_inst, f_audio_alloc);
1019 MODULE_LICENSE("GPL");
1020 MODULE_AUTHOR("Bryan Wu");