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
   9 #include <linux/slab.h>
  10 #include <linux/kernel.h>
  11 #include <linux/module.h>
  12 #include <linux/device.h>
  13 #include <linux/atomic.h>
  14
  15 #include "u_uac1_legacy.h"
  16
  17 static int generic_set_cmd(struct usb_audio_control *con, u8 cmd, int value);
  18 static int generic_get_cmd(struct usb_audio_control *con, u8 cmd);
  19
  20 /*
  21  * DESCRIPTORS ... most are static, but strings and full
  22  * configuration descriptors are built on demand.
  23  */
  24
  25 /*
  26  * We have two interfaces- AudioControl and AudioStreaming
  27  * TODO: only supcard playback currently
  28  */
  29 #define F_AUDIO_AC_INTERFACE    0
  30 #define F_AUDIO_AS_INTERFACE    1
  31 #define F_AUDIO_NUM_INTERFACES  1
  32
  33 /* B.3.1  Standard AC Interface Descriptor */
  34 static struct usb_interface_descriptor ac_interface_desc = {
  35         .bLength =              USB_DT_INTERFACE_SIZE,
  36         .bDescriptorType =      USB_DT_INTERFACE,
  37         .bNumEndpoints =        0,
  38         .bInterfaceClass =      USB_CLASS_AUDIO,
  39         .bInterfaceSubClass =   USB_SUBCLASS_AUDIOCONTROL,
  40 };
  41
  42 /*
  43  * The number of AudioStreaming and MIDIStreaming interfaces
  44  * in the Audio Interface Collection
  45  */
  46 DECLARE_UAC_AC_HEADER_DESCRIPTOR(1);
  47
  48 #define UAC_DT_AC_HEADER_LENGTH UAC_DT_AC_HEADER_SIZE(F_AUDIO_NUM_INTERFACES)
  49 /* 1 input terminal, 1 output terminal and 1 feature unit */
  50 #define UAC_DT_TOTAL_LENGTH (UAC_DT_AC_HEADER_LENGTH + UAC_DT_INPUT_TERMINAL_SIZE \
  51         + UAC_DT_OUTPUT_TERMINAL_SIZE + UAC_DT_FEATURE_UNIT_SIZE(0))
  52 /* B.3.2  Class-Specific AC Interface Descriptor */
  53 static struct uac1_ac_header_descriptor_1 ac_header_desc = {
  54         .bLength =              UAC_DT_AC_HEADER_LENGTH,
  55         .bDescriptorType =      USB_DT_CS_INTERFACE,
  56         .bDescriptorSubtype =   UAC_HEADER,
  57         .bcdADC =               cpu_to_le16(0x0100),
  58         .wTotalLength =         cpu_to_le16(UAC_DT_TOTAL_LENGTH),
  59         .bInCollection =        F_AUDIO_NUM_INTERFACES,
  60         .baInterfaceNr = {
  61         /* Interface number of the first AudioStream interface */
  62                 [0] =           1,
  63         }
  64 };
  65
  66 #define INPUT_TERMINAL_ID       1
  67 static struct uac_input_terminal_descriptor input_terminal_desc = {
  68         .bLength =              UAC_DT_INPUT_TERMINAL_SIZE,
  69         .bDescriptorType =      USB_DT_CS_INTERFACE,
  70         .bDescriptorSubtype =   UAC_INPUT_TERMINAL,
  71         .bTerminalID =          INPUT_TERMINAL_ID,
  72         .wTerminalType =        UAC_TERMINAL_STREAMING,
  73         .bAssocTerminal =       0,
  74         .wChannelConfig =       0x3,
  75 };
  76
  77 DECLARE_UAC_FEATURE_UNIT_DESCRIPTOR(0);
  78
  79 #define FEATURE_UNIT_ID         2
  80 static struct uac_feature_unit_descriptor_0 feature_unit_desc = {
  81         .bLength                = UAC_DT_FEATURE_UNIT_SIZE(0),
  82         .bDescriptorType        = USB_DT_CS_INTERFACE,
  83         .bDescriptorSubtype     = UAC_FEATURE_UNIT,
  84         .bUnitID                = FEATURE_UNIT_ID,
  85         .bSourceID              = INPUT_TERMINAL_ID,
  86         .bControlSize           = 2,
  87         .bmaControls[0]         = (UAC_FU_MUTE | UAC_FU_VOLUME),
  88 };
  89
  90 static struct usb_audio_control mute_control = {
  91         .list = LIST_HEAD_INIT(mute_control.list),
  92         .name = "Mute Control",
  93         .type = UAC_FU_MUTE,
  94         /* Todo: add real Mute control code */
  95         .set = generic_set_cmd,
  96         .get = generic_get_cmd,
  97 };
  98
  99 static struct usb_audio_control volume_control = {
 100         .list = LIST_HEAD_INIT(volume_control.list),
 101         .name = "Volume Control",
 102         .type = UAC_FU_VOLUME,
 103         /* Todo: add real Volume control code */
 104         .set = generic_set_cmd,
 105         .get = generic_get_cmd,
 106 };
 107
 108 static struct usb_audio_control_selector feature_unit = {
 109         .list = LIST_HEAD_INIT(feature_unit.list),
 110         .id = FEATURE_UNIT_ID,
 111         .name = "Mute & Volume Control",
 112         .type = UAC_FEATURE_UNIT,
 113         .desc = (struct usb_descriptor_header *)&feature_unit_desc,
 114 };
 115
 116 #define OUTPUT_TERMINAL_ID      3
 117 static struct uac1_output_terminal_descriptor output_terminal_desc = {
 118         .bLength                = UAC_DT_OUTPUT_TERMINAL_SIZE,
 119         .bDescriptorType        = USB_DT_CS_INTERFACE,
 120         .bDescriptorSubtype     = UAC_OUTPUT_TERMINAL,
 121         .bTerminalID            = OUTPUT_TERMINAL_ID,
 122         .wTerminalType          = UAC_OUTPUT_TERMINAL_SPEAKER,
 123         .bAssocTerminal         = FEATURE_UNIT_ID,
 124         .bSourceID              = FEATURE_UNIT_ID,
 125 };
 126
 127 /* B.4.1  Standard AS Interface Descriptor */
 128 static struct usb_interface_descriptor as_interface_alt_0_desc = {
 129         .bLength =              USB_DT_INTERFACE_SIZE,
 130         .bDescriptorType =      USB_DT_INTERFACE,
 131         .bAlternateSetting =    0,
 132         .bNumEndpoints =        0,
 133         .bInterfaceClass =      USB_CLASS_AUDIO,
 134         .bInterfaceSubClass =   USB_SUBCLASS_AUDIOSTREAMING,
 135 };
 136
 137 static struct usb_interface_descriptor as_interface_alt_1_desc = {
 138         .bLength =              USB_DT_INTERFACE_SIZE,
 139         .bDescriptorType =      USB_DT_INTERFACE,
 140         .bAlternateSetting =    1,
 141         .bNumEndpoints =        1,
 142         .bInterfaceClass =      USB_CLASS_AUDIO,
 143         .bInterfaceSubClass =   USB_SUBCLASS_AUDIOSTREAMING,
 144 };
 145
 146 /* B.4.2  Class-Specific AS Interface Descriptor */
 147 static struct uac1_as_header_descriptor as_header_desc = {
 148         .bLength =              UAC_DT_AS_HEADER_SIZE,
 149         .bDescriptorType =      USB_DT_CS_INTERFACE,
 150         .bDescriptorSubtype =   UAC_AS_GENERAL,
 151         .bTerminalLink =        INPUT_TERMINAL_ID,
 152         .bDelay =               1,
 153         .wFormatTag =           UAC_FORMAT_TYPE_I_PCM,
 154 };
 155
 156 DECLARE_UAC_FORMAT_TYPE_I_DISCRETE_DESC(1);
 157
 158 static struct uac_format_type_i_discrete_descriptor_1 as_type_i_desc = {
 159         .bLength =              UAC_FORMAT_TYPE_I_DISCRETE_DESC_SIZE(1),
 160         .bDescriptorType =      USB_DT_CS_INTERFACE,
 161         .bDescriptorSubtype =   UAC_FORMAT_TYPE,
 162         .bFormatType =          UAC_FORMAT_TYPE_I,
 163         .bSubframeSize =        2,
 164         .bBitResolution =       16,
 165         .bSamFreqType =         1,
 166 };
 167
 168 /* Standard ISO OUT Endpoint Descriptor */
 169 static struct usb_endpoint_descriptor as_out_ep_desc  = {
 170         .bLength =              USB_DT_ENDPOINT_AUDIO_SIZE,
 171         .bDescriptorType =      USB_DT_ENDPOINT,
 172         .bEndpointAddress =     USB_DIR_OUT,
 173         .bmAttributes =         USB_ENDPOINT_SYNC_ADAPTIVE
 174                                 | USB_ENDPOINT_XFER_ISOC,
 175         .wMaxPacketSize =       cpu_to_le16(UAC1_OUT_EP_MAX_PACKET_SIZE),
 176         .bInterval =            4,
 177 };
 178
 179 /* Class-specific AS ISO OUT Endpoint Descriptor */
 180 static struct uac_iso_endpoint_descriptor as_iso_out_desc = {
 181         .bLength =              UAC_ISO_ENDPOINT_DESC_SIZE,
 182         .bDescriptorType =      USB_DT_CS_ENDPOINT,
 183         .bDescriptorSubtype =   UAC_EP_GENERAL,
 184         .bmAttributes =         1,
 185         .bLockDelayUnits =      1,
 186         .wLockDelay =           cpu_to_le16(1),
 187 };
 188
 189 static struct usb_descriptor_header *f_audio_desc[] = {
 190         (struct usb_descriptor_header *)&ac_interface_desc,
 191         (struct usb_descriptor_header *)&ac_header_desc,
 192
 193         (struct usb_descriptor_header *)&input_terminal_desc,
 194         (struct usb_descriptor_header *)&output_terminal_desc,
 195         (struct usb_descriptor_header *)&feature_unit_desc,
 196
 197         (struct usb_descriptor_header *)&as_interface_alt_0_desc,
 198         (struct usb_descriptor_header *)&as_interface_alt_1_desc,
 199         (struct usb_descriptor_header *)&as_header_desc,
 200
 201         (struct usb_descriptor_header *)&as_type_i_desc,
 202
 203         (struct usb_descriptor_header *)&as_out_ep_desc,
 204         (struct usb_descriptor_header *)&as_iso_out_desc,
 205         NULL,
 206 };
 207
 208 enum {
 209         STR_AC_IF,
 210         STR_INPUT_TERMINAL,
 211         STR_INPUT_TERMINAL_CH_NAMES,
 212         STR_FEAT_DESC_0,
 213         STR_OUTPUT_TERMINAL,
 214         STR_AS_IF_ALT0,
 215         STR_AS_IF_ALT1,
 216 };
 217
 218 static struct usb_string strings_uac1[] = {
 219         [STR_AC_IF].s = "AC Interface",
 220         [STR_INPUT_TERMINAL].s = "Input terminal",
 221         [STR_INPUT_TERMINAL_CH_NAMES].s = "Channels",
 222         [STR_FEAT_DESC_0].s = "Volume control & mute",
 223         [STR_OUTPUT_TERMINAL].s = "Output terminal",
 224         [STR_AS_IF_ALT0].s = "AS Interface",
 225         [STR_AS_IF_ALT1].s = "AS Interface",
 226         { },
 227 };
 228
 229 static struct usb_gadget_strings str_uac1 = {
 230         .language = 0x0409,     /* en-us */
 231         .strings = strings_uac1,
 232 };
 233
 234 static struct usb_gadget_strings *uac1_strings[] = {
 235         &str_uac1,
 236         NULL,
 237 };
 238
 239 /*
 240  * This function is an ALSA sound card following USB Audio Class Spec 1.0.
 241  */
 242
 243 /*-------------------------------------------------------------------------*/
 244 struct f_audio_buf {
 245         u8 *buf;
 246         int actual;
 247         struct list_head list;
 248 };
 249
 250 static struct f_audio_buf *f_audio_buffer_alloc(int buf_size)
 251 {
 252         struct f_audio_buf *copy_buf;
 253
 254         copy_buf = kzalloc(sizeof *copy_buf, GFP_ATOMIC);
 255         if (!copy_buf)
 256                 return ERR_PTR(-ENOMEM);
 257
 258         copy_buf->buf = kzalloc(buf_size, GFP_ATOMIC);
 259         if (!copy_buf->buf) {
 260                 kfree(copy_buf);
 261                 return ERR_PTR(-ENOMEM);
 262         }
 263
 264         return copy_buf;
 265 }
 266
 267 static void f_audio_buffer_free(struct f_audio_buf *audio_buf)
 268 {
 269         kfree(audio_buf->buf);
 270         kfree(audio_buf);
 271 }
 272 /*-------------------------------------------------------------------------*/
 273
 274 struct f_audio {
 275         struct gaudio                   card;
 276
 277         u8 ac_intf, ac_alt;
 278         u8 as_intf, as_alt;
 279
 280         /* endpoints handle full and/or high speeds */
 281         struct usb_ep                   *out_ep;
 282
 283         spinlock_t                      lock;
 284         struct f_audio_buf *copy_buf;
 285         struct work_struct playback_work;
 286         struct list_head play_queue;
 287
 288         /* Control Set command */
 289         struct list_head cs;
 290         u8 set_cmd;
 291         struct usb_audio_control *set_con;
 292 };
 293
 294 static inline struct f_audio *func_to_audio(struct usb_function *f)
 295 {
 296         return container_of(f, struct f_audio, card.func);
 297 }
 298
 299 /*-------------------------------------------------------------------------*/
 300
 301 static void f_audio_playback_work(struct work_struct *data)
 302 {
 303         struct f_audio *audio = container_of(data, struct f_audio,
 304                                         playback_work);
 305         struct f_audio_buf *play_buf;
 306
 307         spin_lock_irq(&audio->lock);
 308         if (list_empty(&audio->play_queue)) {
 309                 spin_unlock_irq(&audio->lock);
 310                 return;
 311         }
 312         play_buf = list_first_entry(&audio->play_queue,
 313                         struct f_audio_buf, list);
 314         list_del(&play_buf->list);
 315         spin_unlock_irq(&audio->lock);
 316
 317         u_audio_playback(&audio->card, play_buf->buf, play_buf->actual);
 318         f_audio_buffer_free(play_buf);
 319 }
 320
 321 static int f_audio_out_ep_complete(struct usb_ep *ep, struct usb_request *req)
 322 {
 323         struct f_audio *audio = req->context;
 324         struct usb_composite_dev *cdev = audio->card.func.config->cdev;
 325         struct f_audio_buf *copy_buf = audio->copy_buf;
 326         struct f_uac1_legacy_opts *opts;
 327         int audio_buf_size;
 328         int err;
 329
 330         opts = container_of(audio->card.func.fi, struct f_uac1_legacy_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
 358 static 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
 382 static 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
 418 static 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
 456 static 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
 492 static 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
 520 static int
 521 f_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
 572 static 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_legacy_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_legacy_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         /* No i/f has more than 2 alt settings */
 590         if (alt > 1) {
 591                 ERROR(cdev, "%s:%d Error!\n", __func__, __LINE__);
 592                 return -EINVAL;
 593         }
 594
 595         if (intf == audio->ac_intf) {
 596                 /* Control I/f has only 1 AltSetting - 0 */
 597                 if (alt) {
 598                         ERROR(cdev, "%s:%d Error!\n", __func__, __LINE__);
 599                         return -EINVAL;
 600                 }
 601                 return 0;
 602         } else if (intf == audio->as_intf) {
 603                 if (alt == 1) {
 604                         err = config_ep_by_speed(cdev->gadget, f, out_ep);
 605                         if (err)
 606                                 return err;
 607
 608                         usb_ep_enable(out_ep);
 609                         audio->copy_buf = f_audio_buffer_alloc(audio_buf_size);
 610                         if (IS_ERR(audio->copy_buf))
 611                                 return -ENOMEM;
 612
 613                         /*
 614                          * allocate a bunch of read buffers
 615                          * and queue them all at once.
 616                          */
 617                         for (i = 0; i < req_count && err == 0; i++) {
 618                                 req = usb_ep_alloc_request(out_ep, GFP_ATOMIC);
 619                                 if (req) {
 620                                         req->buf = kzalloc(req_buf_size,
 621                                                         GFP_ATOMIC);
 622                                         if (req->buf) {
 623                                                 req->length = req_buf_size;
 624                                                 req->context = audio;
 625                                                 req->complete =
 626                                                         f_audio_complete;
 627                                                 err = usb_ep_queue(out_ep,
 628                                                         req, GFP_ATOMIC);
 629                                                 if (err)
 630                                                         ERROR(cdev,
 631                                                         "%s queue req: %d\n",
 632                                                         out_ep->name, err);
 633                                         } else
 634                                                 err = -ENOMEM;
 635                                 } else
 636                                         err = -ENOMEM;
 637                         }
 638
 639                 } else {
 640                         struct f_audio_buf *copy_buf = audio->copy_buf;
 641                         if (copy_buf) {
 642                                 list_add_tail(&copy_buf->list,
 643                                                 &audio->play_queue);
 644                                 schedule_work(&audio->playback_work);
 645                         }
 646                 }
 647                 audio->as_alt = alt;
 648         }
 649
 650         return err;
 651 }
 652
 653 static int f_audio_get_alt(struct usb_function *f, unsigned intf)
 654 {
 655         struct f_audio          *audio = func_to_audio(f);
 656         struct usb_composite_dev *cdev = f->config->cdev;
 657
 658         if (intf == audio->ac_intf)
 659                 return audio->ac_alt;
 660         else if (intf == audio->as_intf)
 661                 return audio->as_alt;
 662         else
 663                 ERROR(cdev, "%s:%d Invalid Interface %d!\n",
 664                       __func__, __LINE__, intf);
 665
 666         return -EINVAL;
 667 }
 668
 669 static void f_audio_disable(struct usb_function *f)
 670 {
 671         return;
 672 }
 673
 674 /*-------------------------------------------------------------------------*/
 675
 676 static void f_audio_build_desc(struct f_audio *audio)
 677 {
 678         struct gaudio *card = &audio->card;
 679         u8 *sam_freq;
 680         int rate;
 681
 682         /* Set channel numbers */
 683         input_terminal_desc.bNrChannels = u_audio_get_playback_channels(card);
 684         as_type_i_desc.bNrChannels = u_audio_get_playback_channels(card);
 685
 686         /* Set sample rates */
 687         rate = u_audio_get_playback_rate(card);
 688         sam_freq = as_type_i_desc.tSamFreq[0];
 689         memcpy(sam_freq, &rate, 3);
 690
 691         /* Todo: Set Sample bits and other parameters */
 692
 693         return;
 694 }
 695
 696 /* audio function driver setup/binding */
 697 static int
 698 f_audio_bind(struct usb_configuration *c, struct usb_function *f)
 699 {
 700         struct usb_composite_dev *cdev = c->cdev;
 701         struct f_audio          *audio = func_to_audio(f);
 702         struct usb_string       *us;
 703         int                     status;
 704         struct usb_ep           *ep = NULL;
 705         struct f_uac1_legacy_opts       *audio_opts;
 706
 707         audio_opts = container_of(f->fi, struct f_uac1_legacy_opts, func_inst);
 708         audio->card.gadget = c->cdev->gadget;
 709         /* set up ASLA audio devices */
 710         if (!audio_opts->bound) {
 711                 status = gaudio_setup(&audio->card);
 712                 if (status < 0)
 713                         return status;
 714                 audio_opts->bound = true;
 715         }
 716         us = usb_gstrings_attach(cdev, uac1_strings, ARRAY_SIZE(strings_uac1));
 717         if (IS_ERR(us))
 718                 return PTR_ERR(us);
 719         ac_interface_desc.iInterface = us[STR_AC_IF].id;
 720         input_terminal_desc.iTerminal = us[STR_INPUT_TERMINAL].id;
 721         input_terminal_desc.iChannelNames = us[STR_INPUT_TERMINAL_CH_NAMES].id;
 722         feature_unit_desc.iFeature = us[STR_FEAT_DESC_0].id;
 723         output_terminal_desc.iTerminal = us[STR_OUTPUT_TERMINAL].id;
 724         as_interface_alt_0_desc.iInterface = us[STR_AS_IF_ALT0].id;
 725         as_interface_alt_1_desc.iInterface = us[STR_AS_IF_ALT1].id;
 726
 727
 728         f_audio_build_desc(audio);
 729
 730         /* allocate instance-specific interface IDs, and patch descriptors */
 731         status = usb_interface_id(c, f);
 732         if (status < 0)
 733                 goto fail;
 734         ac_interface_desc.bInterfaceNumber = status;
 735         audio->ac_intf = status;
 736         audio->ac_alt = 0;
 737
 738         status = usb_interface_id(c, f);
 739         if (status < 0)
 740                 goto fail;
 741         as_interface_alt_0_desc.bInterfaceNumber = status;
 742         as_interface_alt_1_desc.bInterfaceNumber = status;
 743         audio->as_intf = status;
 744         audio->as_alt = 0;
 745
 746         status = -ENODEV;
 747
 748         /* allocate instance-specific endpoints */
 749         ep = usb_ep_autoconfig(cdev->gadget, &as_out_ep_desc);
 750         if (!ep)
 751                 goto fail;
 752         audio->out_ep = ep;
 753         audio->out_ep->desc = &as_out_ep_desc;
 754
 755         status = -ENOMEM;
 756
 757         /* copy descriptors, and track endpoint copies */
 758         status = usb_assign_descriptors(f, f_audio_desc, f_audio_desc, NULL,
 759                                         NULL);
 760         if (status)
 761                 goto fail;
 762         return 0;
 763
 764 fail:
 765         gaudio_cleanup(&audio->card);
 766         return status;
 767 }
 768
 769 /*-------------------------------------------------------------------------*/
 770
 771 static int generic_set_cmd(struct usb_audio_control *con, u8 cmd, int value)
 772 {
 773         con->data[cmd] = value;
 774
 775         return 0;
 776 }
 777
 778 static int generic_get_cmd(struct usb_audio_control *con, u8 cmd)
 779 {
 780         return con->data[cmd];
 781 }
 782
 783 /* Todo: add more control selecotor dynamically */
 784 static int control_selector_init(struct f_audio *audio)
 785 {
 786         INIT_LIST_HEAD(&audio->cs);
 787         list_add(&feature_unit.list, &audio->cs);
 788
 789         INIT_LIST_HEAD(&feature_unit.control);
 790         list_add(&mute_control.list, &feature_unit.control);
 791         list_add(&volume_control.list, &feature_unit.control);
 792
 793         volume_control.data[UAC__CUR] = 0xffc0;
 794         volume_control.data[UAC__MIN] = 0xe3a0;
 795         volume_control.data[UAC__MAX] = 0xfff0;
 796         volume_control.data[UAC__RES] = 0x0030;
 797
 798         return 0;
 799 }
 800
 801 static inline
 802 struct f_uac1_legacy_opts *to_f_uac1_opts(struct config_item *item)
 803 {
 804         return container_of(to_config_group(item), struct f_uac1_legacy_opts,
 805                             func_inst.group);
 806 }
 807
 808 static void f_uac1_attr_release(struct config_item *item)
 809 {
 810         struct f_uac1_legacy_opts *opts = to_f_uac1_opts(item);
 811
 812         usb_put_function_instance(&opts->func_inst);
 813 }
 814
 815 static struct configfs_item_operations f_uac1_item_ops = {
 816         .release        = f_uac1_attr_release,
 817 };
 818
 819 #define UAC1_INT_ATTRIBUTE(name)                                        \
 820 static ssize_t f_uac1_opts_##name##_show(struct config_item *item,      \
 821                                          char *page)                    \
 822 {                                                                       \
 823         struct f_uac1_legacy_opts *opts = to_f_uac1_opts(item);         \
 824         int result;                                                     \
 825                                                                         \
 826         mutex_lock(&opts->lock);                                        \
 827         result = sprintf(page, "%u\n", opts->name);                     \
 828         mutex_unlock(&opts->lock);                                      \
 829                                                                         \
 830         return result;                                                  \
 831 }                                                                       \
 832                                                                         \
 833 static ssize_t f_uac1_opts_##name##_store(struct config_item *item,             \
 834                                           const char *page, size_t len) \
 835 {                                                                       \
 836         struct f_uac1_legacy_opts *opts = to_f_uac1_opts(item);         \
 837         int ret;                                                        \
 838         u32 num;                                                        \
 839                                                                         \
 840         mutex_lock(&opts->lock);                                        \
 841         if (opts->refcnt) {                                             \
 842                 ret = -EBUSY;                                           \
 843                 goto end;                                               \
 844         }                                                               \
 845                                                                         \
 846         ret = kstrtou32(page, 0, &num);                                 \
 847         if (ret)                                                        \
 848                 goto end;                                               \
 849                                                                         \
 850         opts->name = num;                                               \
 851         ret = len;                                                      \
 852                                                                         \
 853 end:                                                                    \
 854         mutex_unlock(&opts->lock);                                      \
 855         return ret;                                                     \
 856 }                                                                       \
 857                                                                         \
 858 CONFIGFS_ATTR(f_uac1_opts_, name)
 859
 860 UAC1_INT_ATTRIBUTE(req_buf_size);
 861 UAC1_INT_ATTRIBUTE(req_count);
 862 UAC1_INT_ATTRIBUTE(audio_buf_size);
 863
 864 #define UAC1_STR_ATTRIBUTE(name)                                        \
 865 static ssize_t f_uac1_opts_##name##_show(struct config_item *item,      \
 866                                          char *page)                    \
 867 {                                                                       \
 868         struct f_uac1_legacy_opts *opts = to_f_uac1_opts(item);         \
 869         int result;                                                     \
 870                                                                         \
 871         mutex_lock(&opts->lock);                                        \
 872         result = sprintf(page, "%s\n", opts->name);                     \
 873         mutex_unlock(&opts->lock);                                      \
 874                                                                         \
 875         return result;                                                  \
 876 }                                                                       \
 877                                                                         \
 878 static ssize_t f_uac1_opts_##name##_store(struct config_item *item,     \
 879                                           const char *page, size_t len) \
 880 {                                                                       \
 881         struct f_uac1_legacy_opts *opts = to_f_uac1_opts(item);         \
 882         int ret = -EBUSY;                                               \
 883         char *tmp;                                                      \
 884                                                                         \
 885         mutex_lock(&opts->lock);                                        \
 886         if (opts->refcnt)                                               \
 887                 goto end;                                               \
 888                                                                         \
 889         tmp = kstrndup(page, len, GFP_KERNEL);                          \
 890         if (tmp) {                                                      \
 891                 ret = -ENOMEM;                                          \
 892                 goto end;                                               \
 893         }                                                               \
 894         if (opts->name##_alloc)                                         \
 895                 kfree(opts->name);                                      \
 896         opts->name##_alloc = true;                                      \
 897         opts->name = tmp;                                               \
 898         ret = len;                                                      \
 899                                                                         \
 900 end:                                                                    \
 901         mutex_unlock(&opts->lock);                                      \
 902         return ret;                                                     \
 903 }                                                                       \
 904                                                                         \
 905 CONFIGFS_ATTR(f_uac1_opts_, name)
 906
 907 UAC1_STR_ATTRIBUTE(fn_play);
 908 UAC1_STR_ATTRIBUTE(fn_cap);
 909 UAC1_STR_ATTRIBUTE(fn_cntl);
 910
 911 static struct configfs_attribute *f_uac1_attrs[] = {
 912         &f_uac1_opts_attr_req_buf_size,
 913         &f_uac1_opts_attr_req_count,
 914         &f_uac1_opts_attr_audio_buf_size,
 915         &f_uac1_opts_attr_fn_play,
 916         &f_uac1_opts_attr_fn_cap,
 917         &f_uac1_opts_attr_fn_cntl,
 918         NULL,
 919 };
 920
 921 static const struct config_item_type f_uac1_func_type = {
 922         .ct_item_ops    = &f_uac1_item_ops,
 923         .ct_attrs       = f_uac1_attrs,
 924         .ct_owner       = THIS_MODULE,
 925 };
 926
 927 static void f_audio_free_inst(struct usb_function_instance *f)
 928 {
 929         struct f_uac1_legacy_opts *opts;
 930
 931         opts = container_of(f, struct f_uac1_legacy_opts, func_inst);
 932         if (opts->fn_play_alloc)
 933                 kfree(opts->fn_play);
 934         if (opts->fn_cap_alloc)
 935                 kfree(opts->fn_cap);
 936         if (opts->fn_cntl_alloc)
 937                 kfree(opts->fn_cntl);
 938         kfree(opts);
 939 }
 940
 941 static struct usb_function_instance *f_audio_alloc_inst(void)
 942 {
 943         struct f_uac1_legacy_opts *opts;
 944
 945         opts = kzalloc(sizeof(*opts), GFP_KERNEL);
 946         if (!opts)
 947                 return ERR_PTR(-ENOMEM);
 948
 949         mutex_init(&opts->lock);
 950         opts->func_inst.free_func_inst = f_audio_free_inst;
 951
 952         config_group_init_type_name(&opts->func_inst.group, "",
 953                                     &f_uac1_func_type);
 954
 955         opts->req_buf_size = UAC1_OUT_EP_MAX_PACKET_SIZE;
 956         opts->req_count = UAC1_REQ_COUNT;
 957         opts->audio_buf_size = UAC1_AUDIO_BUF_SIZE;
 958         opts->fn_play = FILE_PCM_PLAYBACK;
 959         opts->fn_cap = FILE_PCM_CAPTURE;
 960         opts->fn_cntl = FILE_CONTROL;
 961         return &opts->func_inst;
 962 }
 963
 964 static void f_audio_free(struct usb_function *f)
 965 {
 966         struct f_audio *audio = func_to_audio(f);
 967         struct f_uac1_legacy_opts *opts;
 968
 969         gaudio_cleanup(&audio->card);
 970         opts = container_of(f->fi, struct f_uac1_legacy_opts, func_inst);
 971         kfree(audio);
 972         mutex_lock(&opts->lock);
 973         --opts->refcnt;
 974         mutex_unlock(&opts->lock);
 975 }
 976
 977 static void f_audio_unbind(struct usb_configuration *c, struct usb_function *f)
 978 {
 979         usb_free_all_descriptors(f);
 980 }
 981
 982 static struct usb_function *f_audio_alloc(struct usb_function_instance *fi)
 983 {
 984         struct f_audio *audio;
 985         struct f_uac1_legacy_opts *opts;
 986
 987         /* allocate and initialize one new instance */
 988         audio = kzalloc(sizeof(*audio), GFP_KERNEL);
 989         if (!audio)
 990                 return ERR_PTR(-ENOMEM);
 991
 992         audio->card.func.name = "g_audio";
 993
 994         opts = container_of(fi, struct f_uac1_legacy_opts, func_inst);
 995         mutex_lock(&opts->lock);
 996         ++opts->refcnt;
 997         mutex_unlock(&opts->lock);
 998         INIT_LIST_HEAD(&audio->play_queue);
 999         spin_lock_init(&audio->lock);
1000
1001         audio->card.func.bind = f_audio_bind;
1002         audio->card.func.unbind = f_audio_unbind;
1003         audio->card.func.set_alt = f_audio_set_alt;
1004         audio->card.func.get_alt = f_audio_get_alt;
1005         audio->card.func.setup = f_audio_setup;
1006         audio->card.func.disable = f_audio_disable;
1007         audio->card.func.free_func = f_audio_free;
1008
1009         control_selector_init(audio);
1010
1011         INIT_WORK(&audio->playback_work, f_audio_playback_work);
1012
1013         return &audio->card.func;
1014 }
1015
1016 DECLARE_USB_FUNCTION_INIT(uac1_legacy, f_audio_alloc_inst, f_audio_alloc);
1017 MODULE_LICENSE("GPL");
1018 MODULE_AUTHOR("Bryan Wu");