linux/drivers/usb/gadget/function/f_uac1.c
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   1// SPDX-License-Identifier: GPL-2.0+
   2/*
   3 * f_uac1.c -- USB Audio Class 1.0 Function (using u_audio API)
   4 *
   5 * Copyright (C) 2016 Ruslan Bilovol <ruslan.bilovol@gmail.com>
   6 *
   7 * This driver doesn't expect any real Audio codec to be present
   8 * on the device - the audio streams are simply sinked to and
   9 * sourced from a virtual ALSA sound card created.
  10 *
  11 * This file is based on f_uac1.c which is
  12 *   Copyright (C) 2008 Bryan Wu <cooloney@kernel.org>
  13 *   Copyright (C) 2008 Analog Devices, Inc
  14 */
  15
  16#include <linux/usb/audio.h>
  17#include <linux/module.h>
  18
  19#include "u_audio.h"
  20#include "u_uac1.h"
  21
  22/* UAC1 spec: 3.7.2.3 Audio Channel Cluster Format */
  23#define UAC1_CHANNEL_MASK 0x0FFF
  24
  25#define EPIN_EN(_opts) ((_opts)->p_chmask != 0)
  26#define EPOUT_EN(_opts) ((_opts)->c_chmask != 0)
  27
  28struct f_uac1 {
  29        struct g_audio g_audio;
  30        u8 ac_intf, as_in_intf, as_out_intf;
  31        u8 ac_alt, as_in_alt, as_out_alt;       /* needed for get_alt() */
  32};
  33
  34static inline struct f_uac1 *func_to_uac1(struct usb_function *f)
  35{
  36        return container_of(f, struct f_uac1, g_audio.func);
  37}
  38
  39static inline struct f_uac1_opts *g_audio_to_uac1_opts(struct g_audio *audio)
  40{
  41        return container_of(audio->func.fi, struct f_uac1_opts, func_inst);
  42}
  43
  44/*
  45 * DESCRIPTORS ... most are static, but strings and full
  46 * configuration descriptors are built on demand.
  47 */
  48
  49/*
  50 * We have three interfaces - one AudioControl and two AudioStreaming
  51 *
  52 * The driver implements a simple UAC_1 topology.
  53 * USB-OUT -> IT_1 -> OT_2 -> ALSA_Capture
  54 * ALSA_Playback -> IT_3 -> OT_4 -> USB-IN
  55 */
  56
  57/* B.3.1  Standard AC Interface Descriptor */
  58static struct usb_interface_descriptor ac_interface_desc = {
  59        .bLength =              USB_DT_INTERFACE_SIZE,
  60        .bDescriptorType =      USB_DT_INTERFACE,
  61        .bNumEndpoints =        0,
  62        .bInterfaceClass =      USB_CLASS_AUDIO,
  63        .bInterfaceSubClass =   USB_SUBCLASS_AUDIOCONTROL,
  64};
  65
  66/* B.3.2  Class-Specific AC Interface Descriptor */
  67static struct uac1_ac_header_descriptor *ac_header_desc;
  68
  69static struct uac_input_terminal_descriptor usb_out_it_desc = {
  70        .bLength =              UAC_DT_INPUT_TERMINAL_SIZE,
  71        .bDescriptorType =      USB_DT_CS_INTERFACE,
  72        .bDescriptorSubtype =   UAC_INPUT_TERMINAL,
  73        /* .bTerminalID =       DYNAMIC */
  74        .wTerminalType =        cpu_to_le16(UAC_TERMINAL_STREAMING),
  75        .bAssocTerminal =       0,
  76        .wChannelConfig =       cpu_to_le16(0x3),
  77};
  78
  79static struct uac1_output_terminal_descriptor io_out_ot_desc = {
  80        .bLength                = UAC_DT_OUTPUT_TERMINAL_SIZE,
  81        .bDescriptorType        = USB_DT_CS_INTERFACE,
  82        .bDescriptorSubtype     = UAC_OUTPUT_TERMINAL,
  83        /* .bTerminalID =       DYNAMIC */
  84        .wTerminalType          = cpu_to_le16(UAC_OUTPUT_TERMINAL_SPEAKER),
  85        .bAssocTerminal         = 0,
  86        /* .bSourceID =         DYNAMIC */
  87};
  88
  89static struct uac_input_terminal_descriptor io_in_it_desc = {
  90        .bLength                = UAC_DT_INPUT_TERMINAL_SIZE,
  91        .bDescriptorType        = USB_DT_CS_INTERFACE,
  92        .bDescriptorSubtype     = UAC_INPUT_TERMINAL,
  93        /* .bTerminalID         = DYNAMIC */
  94        .wTerminalType          = cpu_to_le16(UAC_INPUT_TERMINAL_MICROPHONE),
  95        .bAssocTerminal         = 0,
  96        .wChannelConfig         = cpu_to_le16(0x3),
  97};
  98
  99static struct uac1_output_terminal_descriptor usb_in_ot_desc = {
 100        .bLength =              UAC_DT_OUTPUT_TERMINAL_SIZE,
 101        .bDescriptorType =      USB_DT_CS_INTERFACE,
 102        .bDescriptorSubtype =   UAC_OUTPUT_TERMINAL,
 103        /* .bTerminalID =       DYNAMIC */
 104        .wTerminalType =        cpu_to_le16(UAC_TERMINAL_STREAMING),
 105        .bAssocTerminal =       0,
 106        /* .bSourceID =         DYNAMIC */
 107};
 108
 109/* B.4.1  Standard AS Interface Descriptor */
 110static struct usb_interface_descriptor as_out_interface_alt_0_desc = {
 111        .bLength =              USB_DT_INTERFACE_SIZE,
 112        .bDescriptorType =      USB_DT_INTERFACE,
 113        .bAlternateSetting =    0,
 114        .bNumEndpoints =        0,
 115        .bInterfaceClass =      USB_CLASS_AUDIO,
 116        .bInterfaceSubClass =   USB_SUBCLASS_AUDIOSTREAMING,
 117};
 118
 119static struct usb_interface_descriptor as_out_interface_alt_1_desc = {
 120        .bLength =              USB_DT_INTERFACE_SIZE,
 121        .bDescriptorType =      USB_DT_INTERFACE,
 122        .bAlternateSetting =    1,
 123        .bNumEndpoints =        1,
 124        .bInterfaceClass =      USB_CLASS_AUDIO,
 125        .bInterfaceSubClass =   USB_SUBCLASS_AUDIOSTREAMING,
 126};
 127
 128static struct usb_interface_descriptor as_in_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
 137static struct usb_interface_descriptor as_in_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 */
 147static struct uac1_as_header_descriptor as_out_header_desc = {
 148        .bLength =              UAC_DT_AS_HEADER_SIZE,
 149        .bDescriptorType =      USB_DT_CS_INTERFACE,
 150        .bDescriptorSubtype =   UAC_AS_GENERAL,
 151        /* .bTerminalLink =     DYNAMIC */
 152        .bDelay =               1,
 153        .wFormatTag =           cpu_to_le16(UAC_FORMAT_TYPE_I_PCM),
 154};
 155
 156static struct uac1_as_header_descriptor as_in_header_desc = {
 157        .bLength =              UAC_DT_AS_HEADER_SIZE,
 158        .bDescriptorType =      USB_DT_CS_INTERFACE,
 159        .bDescriptorSubtype =   UAC_AS_GENERAL,
 160        /* .bTerminalLink =     DYNAMIC */
 161        .bDelay =               1,
 162        .wFormatTag =           cpu_to_le16(UAC_FORMAT_TYPE_I_PCM),
 163};
 164
 165DECLARE_UAC_FORMAT_TYPE_I_DISCRETE_DESC(1);
 166
 167static struct uac_format_type_i_discrete_descriptor_1 as_out_type_i_desc = {
 168        .bLength =              UAC_FORMAT_TYPE_I_DISCRETE_DESC_SIZE(1),
 169        .bDescriptorType =      USB_DT_CS_INTERFACE,
 170        .bDescriptorSubtype =   UAC_FORMAT_TYPE,
 171        .bFormatType =          UAC_FORMAT_TYPE_I,
 172        .bSubframeSize =        2,
 173        .bBitResolution =       16,
 174        .bSamFreqType =         1,
 175};
 176
 177/* Standard ISO OUT Endpoint Descriptor */
 178static struct usb_endpoint_descriptor as_out_ep_desc  = {
 179        .bLength =              USB_DT_ENDPOINT_AUDIO_SIZE,
 180        .bDescriptorType =      USB_DT_ENDPOINT,
 181        .bEndpointAddress =     USB_DIR_OUT,
 182        .bmAttributes =         USB_ENDPOINT_SYNC_ADAPTIVE
 183                                | USB_ENDPOINT_XFER_ISOC,
 184        .wMaxPacketSize =       cpu_to_le16(UAC1_OUT_EP_MAX_PACKET_SIZE),
 185        .bInterval =            4,
 186};
 187
 188/* Class-specific AS ISO OUT Endpoint Descriptor */
 189static struct uac_iso_endpoint_descriptor as_iso_out_desc = {
 190        .bLength =              UAC_ISO_ENDPOINT_DESC_SIZE,
 191        .bDescriptorType =      USB_DT_CS_ENDPOINT,
 192        .bDescriptorSubtype =   UAC_EP_GENERAL,
 193        .bmAttributes =         1,
 194        .bLockDelayUnits =      1,
 195        .wLockDelay =           cpu_to_le16(1),
 196};
 197
 198static struct uac_format_type_i_discrete_descriptor_1 as_in_type_i_desc = {
 199        .bLength =              UAC_FORMAT_TYPE_I_DISCRETE_DESC_SIZE(1),
 200        .bDescriptorType =      USB_DT_CS_INTERFACE,
 201        .bDescriptorSubtype =   UAC_FORMAT_TYPE,
 202        .bFormatType =          UAC_FORMAT_TYPE_I,
 203        .bSubframeSize =        2,
 204        .bBitResolution =       16,
 205        .bSamFreqType =         1,
 206};
 207
 208/* Standard ISO OUT Endpoint Descriptor */
 209static struct usb_endpoint_descriptor as_in_ep_desc  = {
 210        .bLength =              USB_DT_ENDPOINT_AUDIO_SIZE,
 211        .bDescriptorType =      USB_DT_ENDPOINT,
 212        .bEndpointAddress =     USB_DIR_IN,
 213        .bmAttributes =         USB_ENDPOINT_SYNC_ASYNC
 214                                | USB_ENDPOINT_XFER_ISOC,
 215        .wMaxPacketSize =       cpu_to_le16(UAC1_OUT_EP_MAX_PACKET_SIZE),
 216        .bInterval =            4,
 217};
 218
 219/* Class-specific AS ISO OUT Endpoint Descriptor */
 220static struct uac_iso_endpoint_descriptor as_iso_in_desc = {
 221        .bLength =              UAC_ISO_ENDPOINT_DESC_SIZE,
 222        .bDescriptorType =      USB_DT_CS_ENDPOINT,
 223        .bDescriptorSubtype =   UAC_EP_GENERAL,
 224        .bmAttributes =         1,
 225        .bLockDelayUnits =      0,
 226        .wLockDelay =           0,
 227};
 228
 229static struct usb_descriptor_header *f_audio_desc[] = {
 230        (struct usb_descriptor_header *)&ac_interface_desc,
 231        (struct usb_descriptor_header *)&ac_header_desc,
 232
 233        (struct usb_descriptor_header *)&usb_out_it_desc,
 234        (struct usb_descriptor_header *)&io_out_ot_desc,
 235        (struct usb_descriptor_header *)&io_in_it_desc,
 236        (struct usb_descriptor_header *)&usb_in_ot_desc,
 237
 238        (struct usb_descriptor_header *)&as_out_interface_alt_0_desc,
 239        (struct usb_descriptor_header *)&as_out_interface_alt_1_desc,
 240        (struct usb_descriptor_header *)&as_out_header_desc,
 241
 242        (struct usb_descriptor_header *)&as_out_type_i_desc,
 243
 244        (struct usb_descriptor_header *)&as_out_ep_desc,
 245        (struct usb_descriptor_header *)&as_iso_out_desc,
 246
 247        (struct usb_descriptor_header *)&as_in_interface_alt_0_desc,
 248        (struct usb_descriptor_header *)&as_in_interface_alt_1_desc,
 249        (struct usb_descriptor_header *)&as_in_header_desc,
 250
 251        (struct usb_descriptor_header *)&as_in_type_i_desc,
 252
 253        (struct usb_descriptor_header *)&as_in_ep_desc,
 254        (struct usb_descriptor_header *)&as_iso_in_desc,
 255        NULL,
 256};
 257
 258enum {
 259        STR_AC_IF,
 260        STR_USB_OUT_IT,
 261        STR_USB_OUT_IT_CH_NAMES,
 262        STR_IO_OUT_OT,
 263        STR_IO_IN_IT,
 264        STR_IO_IN_IT_CH_NAMES,
 265        STR_USB_IN_OT,
 266        STR_AS_OUT_IF_ALT0,
 267        STR_AS_OUT_IF_ALT1,
 268        STR_AS_IN_IF_ALT0,
 269        STR_AS_IN_IF_ALT1,
 270};
 271
 272static struct usb_string strings_uac1[] = {
 273        [STR_AC_IF].s = "AC Interface",
 274        [STR_USB_OUT_IT].s = "Playback Input terminal",
 275        [STR_USB_OUT_IT_CH_NAMES].s = "Playback Channels",
 276        [STR_IO_OUT_OT].s = "Playback Output terminal",
 277        [STR_IO_IN_IT].s = "Capture Input terminal",
 278        [STR_IO_IN_IT_CH_NAMES].s = "Capture Channels",
 279        [STR_USB_IN_OT].s = "Capture Output terminal",
 280        [STR_AS_OUT_IF_ALT0].s = "Playback Inactive",
 281        [STR_AS_OUT_IF_ALT1].s = "Playback Active",
 282        [STR_AS_IN_IF_ALT0].s = "Capture Inactive",
 283        [STR_AS_IN_IF_ALT1].s = "Capture Active",
 284        { },
 285};
 286
 287static struct usb_gadget_strings str_uac1 = {
 288        .language = 0x0409,     /* en-us */
 289        .strings = strings_uac1,
 290};
 291
 292static struct usb_gadget_strings *uac1_strings[] = {
 293        &str_uac1,
 294        NULL,
 295};
 296
 297/*
 298 * This function is an ALSA sound card following USB Audio Class Spec 1.0.
 299 */
 300
 301static int audio_set_endpoint_req(struct usb_function *f,
 302                const struct usb_ctrlrequest *ctrl)
 303{
 304        struct usb_composite_dev *cdev = f->config->cdev;
 305        int                     value = -EOPNOTSUPP;
 306        u16                     ep = le16_to_cpu(ctrl->wIndex);
 307        u16                     len = le16_to_cpu(ctrl->wLength);
 308        u16                     w_value = le16_to_cpu(ctrl->wValue);
 309
 310        DBG(cdev, "bRequest 0x%x, w_value 0x%04x, len %d, endpoint %d\n",
 311                        ctrl->bRequest, w_value, len, ep);
 312
 313        switch (ctrl->bRequest) {
 314        case UAC_SET_CUR:
 315                value = len;
 316                break;
 317
 318        case UAC_SET_MIN:
 319                break;
 320
 321        case UAC_SET_MAX:
 322                break;
 323
 324        case UAC_SET_RES:
 325                break;
 326
 327        case UAC_SET_MEM:
 328                break;
 329
 330        default:
 331                break;
 332        }
 333
 334        return value;
 335}
 336
 337static int audio_get_endpoint_req(struct usb_function *f,
 338                const struct usb_ctrlrequest *ctrl)
 339{
 340        struct usb_composite_dev *cdev = f->config->cdev;
 341        int value = -EOPNOTSUPP;
 342        u8 ep = ((le16_to_cpu(ctrl->wIndex) >> 8) & 0xFF);
 343        u16 len = le16_to_cpu(ctrl->wLength);
 344        u16 w_value = le16_to_cpu(ctrl->wValue);
 345
 346        DBG(cdev, "bRequest 0x%x, w_value 0x%04x, len %d, endpoint %d\n",
 347                        ctrl->bRequest, w_value, len, ep);
 348
 349        switch (ctrl->bRequest) {
 350        case UAC_GET_CUR:
 351        case UAC_GET_MIN:
 352        case UAC_GET_MAX:
 353        case UAC_GET_RES:
 354                value = len;
 355                break;
 356        case UAC_GET_MEM:
 357                break;
 358        default:
 359                break;
 360        }
 361
 362        return value;
 363}
 364
 365static int
 366f_audio_setup(struct usb_function *f, const struct usb_ctrlrequest *ctrl)
 367{
 368        struct usb_composite_dev *cdev = f->config->cdev;
 369        struct usb_request      *req = cdev->req;
 370        int                     value = -EOPNOTSUPP;
 371        u16                     w_index = le16_to_cpu(ctrl->wIndex);
 372        u16                     w_value = le16_to_cpu(ctrl->wValue);
 373        u16                     w_length = le16_to_cpu(ctrl->wLength);
 374
 375        /* composite driver infrastructure handles everything; interface
 376         * activation uses set_alt().
 377         */
 378        switch (ctrl->bRequestType) {
 379        case USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_ENDPOINT:
 380                value = audio_set_endpoint_req(f, ctrl);
 381                break;
 382
 383        case USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_ENDPOINT:
 384                value = audio_get_endpoint_req(f, ctrl);
 385                break;
 386
 387        default:
 388                ERROR(cdev, "invalid control req%02x.%02x v%04x i%04x l%d\n",
 389                        ctrl->bRequestType, ctrl->bRequest,
 390                        w_value, w_index, w_length);
 391        }
 392
 393        /* respond with data transfer or status phase? */
 394        if (value >= 0) {
 395                DBG(cdev, "audio req%02x.%02x v%04x i%04x l%d\n",
 396                        ctrl->bRequestType, ctrl->bRequest,
 397                        w_value, w_index, w_length);
 398                req->zero = 0;
 399                req->length = value;
 400                value = usb_ep_queue(cdev->gadget->ep0, req, GFP_ATOMIC);
 401                if (value < 0)
 402                        ERROR(cdev, "audio response on err %d\n", value);
 403        }
 404
 405        /* device either stalls (value < 0) or reports success */
 406        return value;
 407}
 408
 409static int f_audio_set_alt(struct usb_function *f, unsigned intf, unsigned alt)
 410{
 411        struct usb_composite_dev *cdev = f->config->cdev;
 412        struct usb_gadget *gadget = cdev->gadget;
 413        struct device *dev = &gadget->dev;
 414        struct f_uac1 *uac1 = func_to_uac1(f);
 415        int ret = 0;
 416
 417        /* No i/f has more than 2 alt settings */
 418        if (alt > 1) {
 419                dev_err(dev, "%s:%d Error!\n", __func__, __LINE__);
 420                return -EINVAL;
 421        }
 422
 423        if (intf == uac1->ac_intf) {
 424                /* Control I/f has only 1 AltSetting - 0 */
 425                if (alt) {
 426                        dev_err(dev, "%s:%d Error!\n", __func__, __LINE__);
 427                        return -EINVAL;
 428                }
 429                return 0;
 430        }
 431
 432        if (intf == uac1->as_out_intf) {
 433                uac1->as_out_alt = alt;
 434
 435                if (alt)
 436                        ret = u_audio_start_capture(&uac1->g_audio);
 437                else
 438                        u_audio_stop_capture(&uac1->g_audio);
 439        } else if (intf == uac1->as_in_intf) {
 440                uac1->as_in_alt = alt;
 441
 442                if (alt)
 443                        ret = u_audio_start_playback(&uac1->g_audio);
 444                else
 445                        u_audio_stop_playback(&uac1->g_audio);
 446        } else {
 447                dev_err(dev, "%s:%d Error!\n", __func__, __LINE__);
 448                return -EINVAL;
 449        }
 450
 451        return ret;
 452}
 453
 454static int f_audio_get_alt(struct usb_function *f, unsigned intf)
 455{
 456        struct usb_composite_dev *cdev = f->config->cdev;
 457        struct usb_gadget *gadget = cdev->gadget;
 458        struct device *dev = &gadget->dev;
 459        struct f_uac1 *uac1 = func_to_uac1(f);
 460
 461        if (intf == uac1->ac_intf)
 462                return uac1->ac_alt;
 463        else if (intf == uac1->as_out_intf)
 464                return uac1->as_out_alt;
 465        else if (intf == uac1->as_in_intf)
 466                return uac1->as_in_alt;
 467        else
 468                dev_err(dev, "%s:%d Invalid Interface %d!\n",
 469                        __func__, __LINE__, intf);
 470
 471        return -EINVAL;
 472}
 473
 474
 475static void f_audio_disable(struct usb_function *f)
 476{
 477        struct f_uac1 *uac1 = func_to_uac1(f);
 478
 479        uac1->as_out_alt = 0;
 480        uac1->as_in_alt = 0;
 481
 482        u_audio_stop_playback(&uac1->g_audio);
 483        u_audio_stop_capture(&uac1->g_audio);
 484}
 485
 486/*-------------------------------------------------------------------------*/
 487
 488static struct
 489uac1_ac_header_descriptor *build_ac_header_desc(struct f_uac1_opts *opts)
 490{
 491        struct uac1_ac_header_descriptor *ac_desc;
 492        int ac_header_desc_size;
 493        int num_ifaces = 0;
 494
 495        if (EPOUT_EN(opts))
 496                num_ifaces++;
 497        if (EPIN_EN(opts))
 498                num_ifaces++;
 499
 500        ac_header_desc_size = UAC_DT_AC_HEADER_SIZE(num_ifaces);
 501
 502        ac_desc = kzalloc(ac_header_desc_size, GFP_KERNEL);
 503        if (!ac_desc)
 504                return NULL;
 505
 506        ac_desc->bLength = ac_header_desc_size;
 507        ac_desc->bDescriptorType = USB_DT_CS_INTERFACE;
 508        ac_desc->bDescriptorSubtype = UAC_HEADER;
 509        ac_desc->bcdADC = cpu_to_le16(0x0100);
 510        ac_desc->bInCollection = num_ifaces;
 511
 512        /* wTotalLength and baInterfaceNr will be defined later */
 513
 514        return ac_desc;
 515}
 516
 517/* Use macro to overcome line length limitation */
 518#define USBDHDR(p) (struct usb_descriptor_header *)(p)
 519
 520static void setup_descriptor(struct f_uac1_opts *opts)
 521{
 522        /* patch descriptors */
 523        int i = 1; /* ID's start with 1 */
 524
 525        if (EPOUT_EN(opts))
 526                usb_out_it_desc.bTerminalID = i++;
 527        if (EPIN_EN(opts))
 528                io_in_it_desc.bTerminalID = i++;
 529        if (EPOUT_EN(opts))
 530                io_out_ot_desc.bTerminalID = i++;
 531        if (EPIN_EN(opts))
 532                usb_in_ot_desc.bTerminalID = i++;
 533
 534        usb_in_ot_desc.bSourceID = io_in_it_desc.bTerminalID;
 535        io_out_ot_desc.bSourceID = usb_out_it_desc.bTerminalID;
 536
 537        as_out_header_desc.bTerminalLink = usb_out_it_desc.bTerminalID;
 538        as_in_header_desc.bTerminalLink = usb_in_ot_desc.bTerminalID;
 539
 540        ac_header_desc->wTotalLength = cpu_to_le16(ac_header_desc->bLength);
 541
 542        if (EPIN_EN(opts)) {
 543                u16 len = le16_to_cpu(ac_header_desc->wTotalLength);
 544
 545                len += sizeof(usb_in_ot_desc);
 546                len += sizeof(io_in_it_desc);
 547                ac_header_desc->wTotalLength = cpu_to_le16(len);
 548        }
 549        if (EPOUT_EN(opts)) {
 550                u16 len = le16_to_cpu(ac_header_desc->wTotalLength);
 551
 552                len += sizeof(usb_out_it_desc);
 553                len += sizeof(io_out_ot_desc);
 554                ac_header_desc->wTotalLength = cpu_to_le16(len);
 555        }
 556
 557        i = 0;
 558        f_audio_desc[i++] = USBDHDR(&ac_interface_desc);
 559        f_audio_desc[i++] = USBDHDR(ac_header_desc);
 560
 561        if (EPOUT_EN(opts)) {
 562                f_audio_desc[i++] = USBDHDR(&usb_out_it_desc);
 563                f_audio_desc[i++] = USBDHDR(&io_out_ot_desc);
 564        }
 565
 566        if (EPIN_EN(opts)) {
 567                f_audio_desc[i++] = USBDHDR(&io_in_it_desc);
 568                f_audio_desc[i++] = USBDHDR(&usb_in_ot_desc);
 569        }
 570
 571        if (EPOUT_EN(opts)) {
 572                f_audio_desc[i++] = USBDHDR(&as_out_interface_alt_0_desc);
 573                f_audio_desc[i++] = USBDHDR(&as_out_interface_alt_1_desc);
 574                f_audio_desc[i++] = USBDHDR(&as_out_header_desc);
 575                f_audio_desc[i++] = USBDHDR(&as_out_type_i_desc);
 576                f_audio_desc[i++] = USBDHDR(&as_out_ep_desc);
 577                f_audio_desc[i++] = USBDHDR(&as_iso_out_desc);
 578        }
 579        if (EPIN_EN(opts)) {
 580                f_audio_desc[i++] = USBDHDR(&as_in_interface_alt_0_desc);
 581                f_audio_desc[i++] = USBDHDR(&as_in_interface_alt_1_desc);
 582                f_audio_desc[i++] = USBDHDR(&as_in_header_desc);
 583                f_audio_desc[i++] = USBDHDR(&as_in_type_i_desc);
 584                f_audio_desc[i++] = USBDHDR(&as_in_ep_desc);
 585                f_audio_desc[i++] = USBDHDR(&as_iso_in_desc);
 586        }
 587        f_audio_desc[i] = NULL;
 588}
 589
 590static int f_audio_validate_opts(struct g_audio *audio, struct device *dev)
 591{
 592        struct f_uac1_opts *opts = g_audio_to_uac1_opts(audio);
 593
 594        if (!opts->p_chmask && !opts->c_chmask) {
 595                dev_err(dev, "Error: no playback and capture channels\n");
 596                return -EINVAL;
 597        } else if (opts->p_chmask & ~UAC1_CHANNEL_MASK) {
 598                dev_err(dev, "Error: unsupported playback channels mask\n");
 599                return -EINVAL;
 600        } else if (opts->c_chmask & ~UAC1_CHANNEL_MASK) {
 601                dev_err(dev, "Error: unsupported capture channels mask\n");
 602                return -EINVAL;
 603        } else if ((opts->p_ssize < 1) || (opts->p_ssize > 4)) {
 604                dev_err(dev, "Error: incorrect playback sample size\n");
 605                return -EINVAL;
 606        } else if ((opts->c_ssize < 1) || (opts->c_ssize > 4)) {
 607                dev_err(dev, "Error: incorrect capture sample size\n");
 608                return -EINVAL;
 609        } else if (!opts->p_srate) {
 610                dev_err(dev, "Error: incorrect playback sampling rate\n");
 611                return -EINVAL;
 612        } else if (!opts->c_srate) {
 613                dev_err(dev, "Error: incorrect capture sampling rate\n");
 614                return -EINVAL;
 615        }
 616
 617        return 0;
 618}
 619
 620/* audio function driver setup/binding */
 621static int f_audio_bind(struct usb_configuration *c, struct usb_function *f)
 622{
 623        struct usb_composite_dev        *cdev = c->cdev;
 624        struct usb_gadget               *gadget = cdev->gadget;
 625        struct device                   *dev = &gadget->dev;
 626        struct f_uac1                   *uac1 = func_to_uac1(f);
 627        struct g_audio                  *audio = func_to_g_audio(f);
 628        struct f_uac1_opts              *audio_opts;
 629        struct usb_ep                   *ep = NULL;
 630        struct usb_string               *us;
 631        u8                              *sam_freq;
 632        int                             rate;
 633        int                             ba_iface_id;
 634        int                             status;
 635
 636        status = f_audio_validate_opts(audio, dev);
 637        if (status)
 638                return status;
 639
 640        audio_opts = container_of(f->fi, struct f_uac1_opts, func_inst);
 641
 642        us = usb_gstrings_attach(cdev, uac1_strings, ARRAY_SIZE(strings_uac1));
 643        if (IS_ERR(us))
 644                return PTR_ERR(us);
 645
 646        ac_header_desc = build_ac_header_desc(audio_opts);
 647        if (!ac_header_desc)
 648                return -ENOMEM;
 649
 650        ac_interface_desc.iInterface = us[STR_AC_IF].id;
 651        usb_out_it_desc.iTerminal = us[STR_USB_OUT_IT].id;
 652        usb_out_it_desc.iChannelNames = us[STR_USB_OUT_IT_CH_NAMES].id;
 653        io_out_ot_desc.iTerminal = us[STR_IO_OUT_OT].id;
 654        as_out_interface_alt_0_desc.iInterface = us[STR_AS_OUT_IF_ALT0].id;
 655        as_out_interface_alt_1_desc.iInterface = us[STR_AS_OUT_IF_ALT1].id;
 656        io_in_it_desc.iTerminal = us[STR_IO_IN_IT].id;
 657        io_in_it_desc.iChannelNames = us[STR_IO_IN_IT_CH_NAMES].id;
 658        usb_in_ot_desc.iTerminal = us[STR_USB_IN_OT].id;
 659        as_in_interface_alt_0_desc.iInterface = us[STR_AS_IN_IF_ALT0].id;
 660        as_in_interface_alt_1_desc.iInterface = us[STR_AS_IN_IF_ALT1].id;
 661
 662        /* Set channel numbers */
 663        usb_out_it_desc.bNrChannels = num_channels(audio_opts->c_chmask);
 664        usb_out_it_desc.wChannelConfig = cpu_to_le16(audio_opts->c_chmask);
 665        as_out_type_i_desc.bNrChannels = num_channels(audio_opts->c_chmask);
 666        as_out_type_i_desc.bSubframeSize = audio_opts->c_ssize;
 667        as_out_type_i_desc.bBitResolution = audio_opts->c_ssize * 8;
 668        io_in_it_desc.bNrChannels = num_channels(audio_opts->p_chmask);
 669        io_in_it_desc.wChannelConfig = cpu_to_le16(audio_opts->p_chmask);
 670        as_in_type_i_desc.bNrChannels = num_channels(audio_opts->p_chmask);
 671        as_in_type_i_desc.bSubframeSize = audio_opts->p_ssize;
 672        as_in_type_i_desc.bBitResolution = audio_opts->p_ssize * 8;
 673
 674        /* Set sample rates */
 675        rate = audio_opts->c_srate;
 676        sam_freq = as_out_type_i_desc.tSamFreq[0];
 677        memcpy(sam_freq, &rate, 3);
 678        rate = audio_opts->p_srate;
 679        sam_freq = as_in_type_i_desc.tSamFreq[0];
 680        memcpy(sam_freq, &rate, 3);
 681
 682        /* allocate instance-specific interface IDs, and patch descriptors */
 683        status = usb_interface_id(c, f);
 684        if (status < 0)
 685                goto fail;
 686        ac_interface_desc.bInterfaceNumber = status;
 687        uac1->ac_intf = status;
 688        uac1->ac_alt = 0;
 689
 690        ba_iface_id = 0;
 691
 692        if (EPOUT_EN(audio_opts)) {
 693                status = usb_interface_id(c, f);
 694                if (status < 0)
 695                        goto fail;
 696                as_out_interface_alt_0_desc.bInterfaceNumber = status;
 697                as_out_interface_alt_1_desc.bInterfaceNumber = status;
 698                ac_header_desc->baInterfaceNr[ba_iface_id++] = status;
 699                uac1->as_out_intf = status;
 700                uac1->as_out_alt = 0;
 701        }
 702
 703        if (EPIN_EN(audio_opts)) {
 704                status = usb_interface_id(c, f);
 705                if (status < 0)
 706                        goto fail;
 707                as_in_interface_alt_0_desc.bInterfaceNumber = status;
 708                as_in_interface_alt_1_desc.bInterfaceNumber = status;
 709                ac_header_desc->baInterfaceNr[ba_iface_id++] = status;
 710                uac1->as_in_intf = status;
 711                uac1->as_in_alt = 0;
 712        }
 713
 714        audio->gadget = gadget;
 715
 716        status = -ENODEV;
 717
 718        /* allocate instance-specific endpoints */
 719        if (EPOUT_EN(audio_opts)) {
 720                ep = usb_ep_autoconfig(cdev->gadget, &as_out_ep_desc);
 721                if (!ep)
 722                        goto fail;
 723                audio->out_ep = ep;
 724                audio->out_ep->desc = &as_out_ep_desc;
 725        }
 726
 727        if (EPIN_EN(audio_opts)) {
 728                ep = usb_ep_autoconfig(cdev->gadget, &as_in_ep_desc);
 729                if (!ep)
 730                        goto fail;
 731                audio->in_ep = ep;
 732                audio->in_ep->desc = &as_in_ep_desc;
 733        }
 734
 735        setup_descriptor(audio_opts);
 736
 737        /* copy descriptors, and track endpoint copies */
 738        status = usb_assign_descriptors(f, f_audio_desc, f_audio_desc, NULL,
 739                                        NULL);
 740        if (status)
 741                goto fail;
 742
 743        audio->out_ep_maxpsize = le16_to_cpu(as_out_ep_desc.wMaxPacketSize);
 744        audio->in_ep_maxpsize = le16_to_cpu(as_in_ep_desc.wMaxPacketSize);
 745        audio->params.c_chmask = audio_opts->c_chmask;
 746        audio->params.c_srate = audio_opts->c_srate;
 747        audio->params.c_ssize = audio_opts->c_ssize;
 748        audio->params.p_chmask = audio_opts->p_chmask;
 749        audio->params.p_srate = audio_opts->p_srate;
 750        audio->params.p_ssize = audio_opts->p_ssize;
 751        audio->params.req_number = audio_opts->req_number;
 752
 753        status = g_audio_setup(audio, "UAC1_PCM", "UAC1_Gadget");
 754        if (status)
 755                goto err_card_register;
 756
 757        return 0;
 758
 759err_card_register:
 760        usb_free_all_descriptors(f);
 761fail:
 762        kfree(ac_header_desc);
 763        ac_header_desc = NULL;
 764        return status;
 765}
 766
 767/*-------------------------------------------------------------------------*/
 768
 769static inline struct f_uac1_opts *to_f_uac1_opts(struct config_item *item)
 770{
 771        return container_of(to_config_group(item), struct f_uac1_opts,
 772                            func_inst.group);
 773}
 774
 775static void f_uac1_attr_release(struct config_item *item)
 776{
 777        struct f_uac1_opts *opts = to_f_uac1_opts(item);
 778
 779        usb_put_function_instance(&opts->func_inst);
 780}
 781
 782static struct configfs_item_operations f_uac1_item_ops = {
 783        .release        = f_uac1_attr_release,
 784};
 785
 786#define UAC1_ATTRIBUTE(name)                                            \
 787static ssize_t f_uac1_opts_##name##_show(                               \
 788                                          struct config_item *item,     \
 789                                          char *page)                   \
 790{                                                                       \
 791        struct f_uac1_opts *opts = to_f_uac1_opts(item);                \
 792        int result;                                                     \
 793                                                                        \
 794        mutex_lock(&opts->lock);                                        \
 795        result = sprintf(page, "%u\n", opts->name);                     \
 796        mutex_unlock(&opts->lock);                                      \
 797                                                                        \
 798        return result;                                                  \
 799}                                                                       \
 800                                                                        \
 801static ssize_t f_uac1_opts_##name##_store(                              \
 802                                          struct config_item *item,     \
 803                                          const char *page, size_t len) \
 804{                                                                       \
 805        struct f_uac1_opts *opts = to_f_uac1_opts(item);                \
 806        int ret;                                                        \
 807        u32 num;                                                        \
 808                                                                        \
 809        mutex_lock(&opts->lock);                                        \
 810        if (opts->refcnt) {                                             \
 811                ret = -EBUSY;                                           \
 812                goto end;                                               \
 813        }                                                               \
 814                                                                        \
 815        ret = kstrtou32(page, 0, &num);                                 \
 816        if (ret)                                                        \
 817                goto end;                                               \
 818                                                                        \
 819        opts->name = num;                                               \
 820        ret = len;                                                      \
 821                                                                        \
 822end:                                                                    \
 823        mutex_unlock(&opts->lock);                                      \
 824        return ret;                                                     \
 825}                                                                       \
 826                                                                        \
 827CONFIGFS_ATTR(f_uac1_opts_, name)
 828
 829UAC1_ATTRIBUTE(c_chmask);
 830UAC1_ATTRIBUTE(c_srate);
 831UAC1_ATTRIBUTE(c_ssize);
 832UAC1_ATTRIBUTE(p_chmask);
 833UAC1_ATTRIBUTE(p_srate);
 834UAC1_ATTRIBUTE(p_ssize);
 835UAC1_ATTRIBUTE(req_number);
 836
 837static struct configfs_attribute *f_uac1_attrs[] = {
 838        &f_uac1_opts_attr_c_chmask,
 839        &f_uac1_opts_attr_c_srate,
 840        &f_uac1_opts_attr_c_ssize,
 841        &f_uac1_opts_attr_p_chmask,
 842        &f_uac1_opts_attr_p_srate,
 843        &f_uac1_opts_attr_p_ssize,
 844        &f_uac1_opts_attr_req_number,
 845        NULL,
 846};
 847
 848static const struct config_item_type f_uac1_func_type = {
 849        .ct_item_ops    = &f_uac1_item_ops,
 850        .ct_attrs       = f_uac1_attrs,
 851        .ct_owner       = THIS_MODULE,
 852};
 853
 854static void f_audio_free_inst(struct usb_function_instance *f)
 855{
 856        struct f_uac1_opts *opts;
 857
 858        opts = container_of(f, struct f_uac1_opts, func_inst);
 859        kfree(opts);
 860}
 861
 862static struct usb_function_instance *f_audio_alloc_inst(void)
 863{
 864        struct f_uac1_opts *opts;
 865
 866        opts = kzalloc(sizeof(*opts), GFP_KERNEL);
 867        if (!opts)
 868                return ERR_PTR(-ENOMEM);
 869
 870        mutex_init(&opts->lock);
 871        opts->func_inst.free_func_inst = f_audio_free_inst;
 872
 873        config_group_init_type_name(&opts->func_inst.group, "",
 874                                    &f_uac1_func_type);
 875
 876        opts->c_chmask = UAC1_DEF_CCHMASK;
 877        opts->c_srate = UAC1_DEF_CSRATE;
 878        opts->c_ssize = UAC1_DEF_CSSIZE;
 879        opts->p_chmask = UAC1_DEF_PCHMASK;
 880        opts->p_srate = UAC1_DEF_PSRATE;
 881        opts->p_ssize = UAC1_DEF_PSSIZE;
 882        opts->req_number = UAC1_DEF_REQ_NUM;
 883        return &opts->func_inst;
 884}
 885
 886static void f_audio_free(struct usb_function *f)
 887{
 888        struct g_audio *audio;
 889        struct f_uac1_opts *opts;
 890
 891        audio = func_to_g_audio(f);
 892        opts = container_of(f->fi, struct f_uac1_opts, func_inst);
 893        kfree(audio);
 894        mutex_lock(&opts->lock);
 895        --opts->refcnt;
 896        mutex_unlock(&opts->lock);
 897}
 898
 899static void f_audio_unbind(struct usb_configuration *c, struct usb_function *f)
 900{
 901        struct g_audio *audio = func_to_g_audio(f);
 902
 903        g_audio_cleanup(audio);
 904        usb_free_all_descriptors(f);
 905
 906        kfree(ac_header_desc);
 907        ac_header_desc = NULL;
 908
 909        audio->gadget = NULL;
 910}
 911
 912static struct usb_function *f_audio_alloc(struct usb_function_instance *fi)
 913{
 914        struct f_uac1 *uac1;
 915        struct f_uac1_opts *opts;
 916
 917        /* allocate and initialize one new instance */
 918        uac1 = kzalloc(sizeof(*uac1), GFP_KERNEL);
 919        if (!uac1)
 920                return ERR_PTR(-ENOMEM);
 921
 922        opts = container_of(fi, struct f_uac1_opts, func_inst);
 923        mutex_lock(&opts->lock);
 924        ++opts->refcnt;
 925        mutex_unlock(&opts->lock);
 926
 927        uac1->g_audio.func.name = "uac1_func";
 928        uac1->g_audio.func.bind = f_audio_bind;
 929        uac1->g_audio.func.unbind = f_audio_unbind;
 930        uac1->g_audio.func.set_alt = f_audio_set_alt;
 931        uac1->g_audio.func.get_alt = f_audio_get_alt;
 932        uac1->g_audio.func.setup = f_audio_setup;
 933        uac1->g_audio.func.disable = f_audio_disable;
 934        uac1->g_audio.func.free_func = f_audio_free;
 935
 936        return &uac1->g_audio.func;
 937}
 938
 939DECLARE_USB_FUNCTION_INIT(uac1, f_audio_alloc_inst, f_audio_alloc);
 940MODULE_LICENSE("GPL");
 941MODULE_AUTHOR("Ruslan Bilovol");
 942