drivers/usb/gadget/f_accessory.c

   1 /*
   2  * Gadget Function Driver for Android USB accessories
   3  *
   4  * Copyright (C) 2011 Google, Inc.
   5  * Author: Mike Lockwood <lockwood@android.com>
   6  *
   7  * This software is licensed under the terms of the GNU General Public
   8  * License version 2, as published by the Free Software Foundation, and
   9  * may be copied, distributed, and modified under those terms.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  */
  17
  18 /* #define DEBUG */
  19 /* #define VERBOSE_DEBUG */
  20
  21 #include <linux/module.h>
  22 #include <linux/init.h>
  23 #include <linux/poll.h>
  24 #include <linux/delay.h>
  25 #include <linux/wait.h>
  26 #include <linux/err.h>
  27 #include <linux/interrupt.h>
  28 #include <linux/kthread.h>
  29 #include <linux/freezer.h>
  30
  31 #include <linux/types.h>
  32 #include <linux/file.h>
  33 #include <linux/device.h>
  34 #include <linux/miscdevice.h>
  35
  36 #include <linux/hid.h>
  37 #include <linux/hiddev.h>
  38 #include <linux/usb.h>
  39 #include <linux/usb/ch9.h>
  40 #include <linux/usb/f_accessory.h>
  41
  42 #define BULK_BUFFER_SIZE    16384
  43 #define ACC_STRING_SIZE     256
  44
  45 #define PROTOCOL_VERSION    2
  46
  47 /* String IDs */
  48 #define INTERFACE_STRING_INDEX  0
  49
  50 /* number of tx and rx requests to allocate */
  51 #define TX_REQ_MAX 4
  52 #define RX_REQ_MAX 2
  53
  54 struct acc_hid_dev {
  55         struct list_head        list;
  56         struct hid_device *hid;
  57         struct acc_dev *dev;
  58         /* accessory defined ID */
  59         int id;
  60         /* HID report descriptor */
  61         u8 *report_desc;
  62         /* length of HID report descriptor */
  63         int report_desc_len;
  64         /* number of bytes of report_desc we have received so far */
  65         int report_desc_offset;
  66 };
  67
  68 struct acc_dev {
  69         struct usb_function function;
  70         struct usb_composite_dev *cdev;
  71         spinlock_t lock;
  72
  73         struct usb_ep *ep_in;
  74         struct usb_ep *ep_out;
  75
  76         /* set to 1 when we connect */
  77         int online:1;
  78         /* Set to 1 when we disconnect.
  79          * Not cleared until our file is closed.
  80          */
  81         int disconnected:1;
  82
  83         /* strings sent by the host */
  84         char manufacturer[ACC_STRING_SIZE];
  85         char model[ACC_STRING_SIZE];
  86         char description[ACC_STRING_SIZE];
  87         char version[ACC_STRING_SIZE];
  88         char uri[ACC_STRING_SIZE];
  89         char serial[ACC_STRING_SIZE];
  90
  91         /* for acc_complete_set_string */
  92         int string_index;
  93
  94         /* set to 1 if we have a pending start request */
  95         int start_requested;
  96
  97         int audio_mode;
  98
  99         /* synchronize access to our device file */
 100         atomic_t open_excl;
 101
 102         struct list_head tx_idle;
 103
 104         wait_queue_head_t read_wq;
 105         wait_queue_head_t write_wq;
 106         struct usb_request *rx_req[RX_REQ_MAX];
 107         int rx_done;
 108
 109         /* delayed work for handling ACCESSORY_START */
 110         struct delayed_work start_work;
 111
 112         /* worker for registering and unregistering hid devices */
 113         struct work_struct hid_work;
 114
 115         /* list of active HID devices */
 116         struct list_head        hid_list;
 117
 118         /* list of new HID devices to register */
 119         struct list_head        new_hid_list;
 120
 121         /* list of dead HID devices to unregister */
 122         struct list_head        dead_hid_list;
 123 };
 124
 125 static struct usb_interface_descriptor acc_interface_desc = {
 126         .bLength                = USB_DT_INTERFACE_SIZE,
 127         .bDescriptorType        = USB_DT_INTERFACE,
 128         .bInterfaceNumber       = 0,
 129         .bNumEndpoints          = 2,
 130         .bInterfaceClass        = USB_CLASS_VENDOR_SPEC,
 131         .bInterfaceSubClass     = USB_SUBCLASS_VENDOR_SPEC,
 132         .bInterfaceProtocol     = 0,
 133 };
 134
 135 static struct usb_endpoint_descriptor acc_highspeed_in_desc = {
 136         .bLength                = USB_DT_ENDPOINT_SIZE,
 137         .bDescriptorType        = USB_DT_ENDPOINT,
 138         .bEndpointAddress       = USB_DIR_IN,
 139         .bmAttributes           = USB_ENDPOINT_XFER_BULK,
 140         .wMaxPacketSize         = __constant_cpu_to_le16(512),
 141 };
 142
 143 static struct usb_endpoint_descriptor acc_highspeed_out_desc = {
 144         .bLength                = USB_DT_ENDPOINT_SIZE,
 145         .bDescriptorType        = USB_DT_ENDPOINT,
 146         .bEndpointAddress       = USB_DIR_OUT,
 147         .bmAttributes           = USB_ENDPOINT_XFER_BULK,
 148         .wMaxPacketSize         = __constant_cpu_to_le16(512),
 149 };
 150
 151 static struct usb_endpoint_descriptor acc_fullspeed_in_desc = {
 152         .bLength                = USB_DT_ENDPOINT_SIZE,
 153         .bDescriptorType        = USB_DT_ENDPOINT,
 154         .bEndpointAddress       = USB_DIR_IN,
 155         .bmAttributes           = USB_ENDPOINT_XFER_BULK,
 156 };
 157
 158 static struct usb_endpoint_descriptor acc_fullspeed_out_desc = {
 159         .bLength                = USB_DT_ENDPOINT_SIZE,
 160         .bDescriptorType        = USB_DT_ENDPOINT,
 161         .bEndpointAddress       = USB_DIR_OUT,
 162         .bmAttributes           = USB_ENDPOINT_XFER_BULK,
 163 };
 164
 165 static struct usb_descriptor_header *fs_acc_descs[] = {
 166         (struct usb_descriptor_header *) &acc_interface_desc,
 167         (struct usb_descriptor_header *) &acc_fullspeed_in_desc,
 168         (struct usb_descriptor_header *) &acc_fullspeed_out_desc,
 169         NULL,
 170 };
 171
 172 static struct usb_descriptor_header *hs_acc_descs[] = {
 173         (struct usb_descriptor_header *) &acc_interface_desc,
 174         (struct usb_descriptor_header *) &acc_highspeed_in_desc,
 175         (struct usb_descriptor_header *) &acc_highspeed_out_desc,
 176         NULL,
 177 };
 178
 179 static struct usb_string acc_string_defs[] = {
 180         [INTERFACE_STRING_INDEX].s      = "Android Accessory Interface",
 181         {  },   /* end of list */
 182 };
 183
 184 static struct usb_gadget_strings acc_string_table = {
 185         .language               = 0x0409,       /* en-US */
 186         .strings                = acc_string_defs,
 187 };
 188
 189 static struct usb_gadget_strings *acc_strings[] = {
 190         &acc_string_table,
 191         NULL,
 192 };
 193
 194 /* temporary variable used between acc_open() and acc_gadget_bind() */
 195 static struct acc_dev *_acc_dev;
 196
 197 static inline struct acc_dev *func_to_dev(struct usb_function *f)
 198 {
 199         return container_of(f, struct acc_dev, function);
 200 }
 201
 202 static struct usb_request *acc_request_new(struct usb_ep *ep, int buffer_size)
 203 {
 204         struct usb_request *req = usb_ep_alloc_request(ep, GFP_KERNEL);
 205         if (!req)
 206                 return NULL;
 207
 208         /* now allocate buffers for the requests */
 209         req->buf = kmalloc(buffer_size, GFP_KERNEL);
 210         if (!req->buf) {
 211                 usb_ep_free_request(ep, req);
 212                 return NULL;
 213         }
 214
 215         return req;
 216 }
 217
 218 static void acc_request_free(struct usb_request *req, struct usb_ep *ep)
 219 {
 220         if (req) {
 221                 kfree(req->buf);
 222                 usb_ep_free_request(ep, req);
 223         }
 224 }
 225
 226 /* add a request to the tail of a list */
 227 static void req_put(struct acc_dev *dev, struct list_head *head,
 228                 struct usb_request *req)
 229 {
 230         unsigned long flags;
 231
 232         spin_lock_irqsave(&dev->lock, flags);
 233         list_add_tail(&req->list, head);
 234         spin_unlock_irqrestore(&dev->lock, flags);
 235 }
 236
 237 /* remove a request from the head of a list */
 238 static struct usb_request *req_get(struct acc_dev *dev, struct list_head *head)
 239 {
 240         unsigned long flags;
 241         struct usb_request *req;
 242
 243         spin_lock_irqsave(&dev->lock, flags);
 244         if (list_empty(head)) {
 245                 req = 0;
 246         } else {
 247                 req = list_first_entry(head, struct usb_request, list);
 248                 list_del(&req->list);
 249         }
 250         spin_unlock_irqrestore(&dev->lock, flags);
 251         return req;
 252 }
 253
 254 static void acc_set_disconnected(struct acc_dev *dev)
 255 {
 256         dev->online = 0;
 257         dev->disconnected = 1;
 258 }
 259
 260 static void acc_complete_in(struct usb_ep *ep, struct usb_request *req)
 261 {
 262         struct acc_dev *dev = _acc_dev;
 263
 264         if (req->status != 0)
 265                 acc_set_disconnected(dev);
 266
 267         req_put(dev, &dev->tx_idle, req);
 268
 269         wake_up(&dev->write_wq);
 270 }
 271
 272 static void acc_complete_out(struct usb_ep *ep, struct usb_request *req)
 273 {
 274         struct acc_dev *dev = _acc_dev;
 275
 276         dev->rx_done = 1;
 277         if (req->status != 0)
 278                 acc_set_disconnected(dev);
 279
 280         wake_up(&dev->read_wq);
 281 }
 282
 283 static void acc_complete_set_string(struct usb_ep *ep, struct usb_request *req)
 284 {
 285         struct acc_dev  *dev = ep->driver_data;
 286         char *string_dest = NULL;
 287         int length = req->actual;
 288
 289         if (req->status != 0) {
 290                 pr_err("acc_complete_set_string, err %d\n", req->status);
 291                 return;
 292         }
 293
 294         switch (dev->string_index) {
 295         case ACCESSORY_STRING_MANUFACTURER:
 296                 string_dest = dev->manufacturer;
 297                 break;
 298         case ACCESSORY_STRING_MODEL:
 299                 string_dest = dev->model;
 300                 break;
 301         case ACCESSORY_STRING_DESCRIPTION:
 302                 string_dest = dev->description;
 303                 break;
 304         case ACCESSORY_STRING_VERSION:
 305                 string_dest = dev->version;
 306                 break;
 307         case ACCESSORY_STRING_URI:
 308                 string_dest = dev->uri;
 309                 break;
 310         case ACCESSORY_STRING_SERIAL:
 311                 string_dest = dev->serial;
 312                 break;
 313         }
 314         if (string_dest) {
 315                 unsigned long flags;
 316
 317                 if (length >= ACC_STRING_SIZE)
 318                         length = ACC_STRING_SIZE - 1;
 319
 320                 spin_lock_irqsave(&dev->lock, flags);
 321                 memcpy(string_dest, req->buf, length);
 322                 /* ensure zero termination */
 323                 string_dest[length] = 0;
 324                 spin_unlock_irqrestore(&dev->lock, flags);
 325         } else {
 326                 pr_err("unknown accessory string index %d\n",
 327                         dev->string_index);
 328         }
 329 }
 330
 331 static void acc_complete_set_hid_report_desc(struct usb_ep *ep,
 332                 struct usb_request *req)
 333 {
 334         struct acc_hid_dev *hid = req->context;
 335         struct acc_dev *dev = hid->dev;
 336         int length = req->actual;
 337
 338         if (req->status != 0) {
 339                 pr_err("acc_complete_set_hid_report_desc, err %d\n",
 340                         req->status);
 341                 return;
 342         }
 343
 344         memcpy(hid->report_desc + hid->report_desc_offset, req->buf, length);
 345         hid->report_desc_offset += length;
 346         if (hid->report_desc_offset == hid->report_desc_len) {
 347                 /* After we have received the entire report descriptor
 348                  * we schedule work to initialize the HID device
 349                  */
 350                 schedule_work(&dev->hid_work);
 351         }
 352 }
 353
 354 static void acc_complete_send_hid_event(struct usb_ep *ep,
 355                 struct usb_request *req)
 356 {
 357         struct acc_hid_dev *hid = req->context;
 358         int length = req->actual;
 359
 360         if (req->status != 0) {
 361                 pr_err("acc_complete_send_hid_event, err %d\n", req->status);
 362                 return;
 363         }
 364
 365         hid_report_raw_event(hid->hid, HID_INPUT_REPORT, req->buf, length, 1);
 366 }
 367
 368 static int acc_hid_parse(struct hid_device *hid)
 369 {
 370         struct acc_hid_dev *hdev = hid->driver_data;
 371
 372         hid_parse_report(hid, hdev->report_desc, hdev->report_desc_len);
 373         return 0;
 374 }
 375
 376 static int acc_hid_start(struct hid_device *hid)
 377 {
 378         return 0;
 379 }
 380
 381 static void acc_hid_stop(struct hid_device *hid)
 382 {
 383 }
 384
 385 static int acc_hid_open(struct hid_device *hid)
 386 {
 387         return 0;
 388 }
 389
 390 static void acc_hid_close(struct hid_device *hid)
 391 {
 392 }
 393
 394 static struct hid_ll_driver acc_hid_ll_driver = {
 395         .parse = acc_hid_parse,
 396         .start = acc_hid_start,
 397         .stop = acc_hid_stop,
 398         .open = acc_hid_open,
 399         .close = acc_hid_close,
 400 };
 401
 402 static struct acc_hid_dev *acc_hid_new(struct acc_dev *dev,
 403                 int id, int desc_len)
 404 {
 405         struct acc_hid_dev *hdev;
 406
 407         hdev = kzalloc(sizeof(*hdev), GFP_ATOMIC);
 408         if (!hdev)
 409                 return NULL;
 410         hdev->report_desc = kzalloc(desc_len, GFP_ATOMIC);
 411         if (!hdev->report_desc) {
 412                 kfree(hdev);
 413                 return NULL;
 414         }
 415         hdev->dev = dev;
 416         hdev->id = id;
 417         hdev->report_desc_len = desc_len;
 418
 419         return hdev;
 420 }
 421
 422 static struct acc_hid_dev *acc_hid_get(struct list_head *list, int id)
 423 {
 424         struct acc_hid_dev *hid;
 425
 426         list_for_each_entry(hid, list, list) {
 427                 if (hid->id == id)
 428                         return hid;
 429         }
 430         return NULL;
 431 }
 432
 433 static int acc_register_hid(struct acc_dev *dev, int id, int desc_length)
 434 {
 435         struct acc_hid_dev *hid;
 436         unsigned long flags;
 437
 438         /* report descriptor length must be > 0 */
 439         if (desc_length <= 0)
 440                 return -EINVAL;
 441
 442         spin_lock_irqsave(&dev->lock, flags);
 443         /* replace HID if one already exists with this ID */
 444         hid = acc_hid_get(&dev->hid_list, id);
 445         if (!hid)
 446                 hid = acc_hid_get(&dev->new_hid_list, id);
 447         if (hid)
 448                 list_move(&hid->list, &dev->dead_hid_list);
 449
 450         hid = acc_hid_new(dev, id, desc_length);
 451         if (!hid) {
 452                 spin_unlock_irqrestore(&dev->lock, flags);
 453                 return -ENOMEM;
 454         }
 455
 456         list_add(&hid->list, &dev->new_hid_list);
 457         spin_unlock_irqrestore(&dev->lock, flags);
 458
 459         /* schedule work to register the HID device */
 460         schedule_work(&dev->hid_work);
 461         return 0;
 462 }
 463
 464 static int acc_unregister_hid(struct acc_dev *dev, int id)
 465 {
 466         struct acc_hid_dev *hid;
 467         unsigned long flags;
 468
 469         spin_lock_irqsave(&dev->lock, flags);
 470         hid = acc_hid_get(&dev->hid_list, id);
 471         if (!hid)
 472                 hid = acc_hid_get(&dev->new_hid_list, id);
 473         if (!hid) {
 474                 spin_unlock_irqrestore(&dev->lock, flags);
 475                 return -EINVAL;
 476         }
 477
 478         list_move(&hid->list, &dev->dead_hid_list);
 479         spin_unlock_irqrestore(&dev->lock, flags);
 480
 481         schedule_work(&dev->hid_work);
 482         return 0;
 483 }
 484
 485 static int create_bulk_endpoints(struct acc_dev *dev,
 486                                 struct usb_endpoint_descriptor *in_desc,
 487                                 struct usb_endpoint_descriptor *out_desc)
 488 {
 489         struct usb_composite_dev *cdev = dev->cdev;
 490         struct usb_request *req;
 491         struct usb_ep *ep;
 492         int i;
 493
 494         DBG(cdev, "create_bulk_endpoints dev: %p\n", dev);
 495
 496         ep = usb_ep_autoconfig(cdev->gadget, in_desc);
 497         if (!ep) {
 498                 DBG(cdev, "usb_ep_autoconfig for ep_in failed\n");
 499                 return -ENODEV;
 500         }
 501         DBG(cdev, "usb_ep_autoconfig for ep_in got %s\n", ep->name);
 502         ep->driver_data = dev;          /* claim the endpoint */
 503         dev->ep_in = ep;
 504
 505         ep = usb_ep_autoconfig(cdev->gadget, out_desc);
 506         if (!ep) {
 507                 DBG(cdev, "usb_ep_autoconfig for ep_out failed\n");
 508                 return -ENODEV;
 509         }
 510         DBG(cdev, "usb_ep_autoconfig for ep_out got %s\n", ep->name);
 511         ep->driver_data = dev;          /* claim the endpoint */
 512         dev->ep_out = ep;
 513
 514         ep = usb_ep_autoconfig(cdev->gadget, out_desc);
 515         if (!ep) {
 516                 DBG(cdev, "usb_ep_autoconfig for ep_out failed\n");
 517                 return -ENODEV;
 518         }
 519         DBG(cdev, "usb_ep_autoconfig for ep_out got %s\n", ep->name);
 520         ep->driver_data = dev;          /* claim the endpoint */
 521         dev->ep_out = ep;
 522
 523         /* now allocate requests for our endpoints */
 524         for (i = 0; i < TX_REQ_MAX; i++) {
 525                 req = acc_request_new(dev->ep_in, BULK_BUFFER_SIZE);
 526                 if (!req)
 527                         goto fail;
 528                 req->complete = acc_complete_in;
 529                 req_put(dev, &dev->tx_idle, req);
 530         }
 531         for (i = 0; i < RX_REQ_MAX; i++) {
 532                 req = acc_request_new(dev->ep_out, BULK_BUFFER_SIZE);
 533                 if (!req)
 534                         goto fail;
 535                 req->complete = acc_complete_out;
 536                 dev->rx_req[i] = req;
 537         }
 538
 539         return 0;
 540
 541 fail:
 542         pr_err("acc_bind() could not allocate requests\n");
 543         while ((req = req_get(dev, &dev->tx_idle)))
 544                 acc_request_free(req, dev->ep_in);
 545         for (i = 0; i < RX_REQ_MAX; i++)
 546                 acc_request_free(dev->rx_req[i], dev->ep_out);
 547         return -1;
 548 }
 549
 550 static ssize_t acc_read(struct file *fp, char __user *buf,
 551         size_t count, loff_t *pos)
 552 {
 553         struct acc_dev *dev = fp->private_data;
 554         struct usb_request *req;
 555         int r = count, xfer;
 556         int ret = 0;
 557
 558         pr_debug("acc_read(%d)\n", count);
 559
 560         if (dev->disconnected)
 561                 return -ENODEV;
 562
 563         if (count > BULK_BUFFER_SIZE)
 564                 count = BULK_BUFFER_SIZE;
 565
 566         /* we will block until we're online */
 567         pr_debug("acc_read: waiting for online\n");
 568         ret = wait_event_interruptible(dev->read_wq, dev->online);
 569         if (ret < 0) {
 570                 r = ret;
 571                 goto done;
 572         }
 573
 574 requeue_req:
 575         /* queue a request */
 576         req = dev->rx_req[0];
 577         req->length = count;
 578         dev->rx_done = 0;
 579         ret = usb_ep_queue(dev->ep_out, req, GFP_KERNEL);
 580         if (ret < 0) {
 581                 r = -EIO;
 582                 goto done;
 583         } else {
 584                 pr_debug("rx %p queue\n", req);
 585         }
 586
 587         /* wait for a request to complete */
 588         ret = wait_event_interruptible(dev->read_wq, dev->rx_done);
 589         if (ret < 0) {
 590                 r = ret;
 591                 usb_ep_dequeue(dev->ep_out, req);
 592                 goto done;
 593         }
 594         if (dev->online) {
 595                 /* If we got a 0-len packet, throw it back and try again. */
 596                 if (req->actual == 0)
 597                         goto requeue_req;
 598
 599                 pr_debug("rx %p %d\n", req, req->actual);
 600                 xfer = (req->actual < count) ? req->actual : count;
 601                 r = xfer;
 602                 if (copy_to_user(buf, req->buf, xfer))
 603                         r = -EFAULT;
 604         } else
 605                 r = -EIO;
 606
 607 done:
 608         pr_debug("acc_read returning %d\n", r);
 609         return r;
 610 }
 611
 612 static ssize_t acc_write(struct file *fp, const char __user *buf,
 613         size_t count, loff_t *pos)
 614 {
 615         struct acc_dev *dev = fp->private_data;
 616         struct usb_request *req = 0;
 617         int r = count, xfer;
 618         int ret;
 619
 620         pr_debug("acc_write(%d)\n", count);
 621
 622         if (!dev->online || dev->disconnected)
 623                 return -ENODEV;
 624
 625         while (count > 0) {
 626                 if (!dev->online) {
 627                         pr_debug("acc_write dev->error\n");
 628                         r = -EIO;
 629                         break;
 630                 }
 631
 632                 /* get an idle tx request to use */
 633                 req = 0;
 634                 ret = wait_event_interruptible(dev->write_wq,
 635                         ((req = req_get(dev, &dev->tx_idle)) || !dev->online));
 636                 if (!req) {
 637                         r = ret;
 638                         break;
 639                 }
 640
 641                 if (count > BULK_BUFFER_SIZE)
 642                         xfer = BULK_BUFFER_SIZE;
 643                 else
 644                         xfer = count;
 645                 if (copy_from_user(req->buf, buf, xfer)) {
 646                         r = -EFAULT;
 647                         break;
 648                 }
 649
 650                 req->length = xfer;
 651                 ret = usb_ep_queue(dev->ep_in, req, GFP_KERNEL);
 652                 if (ret < 0) {
 653                         pr_debug("acc_write: xfer error %d\n", ret);
 654                         r = -EIO;
 655                         break;
 656                 }
 657
 658                 buf += xfer;
 659                 count -= xfer;
 660
 661                 /* zero this so we don't try to free it on error exit */
 662                 req = 0;
 663         }
 664
 665         if (req)
 666                 req_put(dev, &dev->tx_idle, req);
 667
 668         pr_debug("acc_write returning %d\n", r);
 669         return r;
 670 }
 671
 672 static long acc_ioctl(struct file *fp, unsigned code, unsigned long value)
 673 {
 674         struct acc_dev *dev = fp->private_data;
 675         char *src = NULL;
 676         int ret;
 677
 678         switch (code) {
 679         case ACCESSORY_GET_STRING_MANUFACTURER:
 680                 src = dev->manufacturer;
 681                 break;
 682         case ACCESSORY_GET_STRING_MODEL:
 683                 src = dev->model;
 684                 break;
 685         case ACCESSORY_GET_STRING_DESCRIPTION:
 686                 src = dev->description;
 687                 break;
 688         case ACCESSORY_GET_STRING_VERSION:
 689                 src = dev->version;
 690                 break;
 691         case ACCESSORY_GET_STRING_URI:
 692                 src = dev->uri;
 693                 break;
 694         case ACCESSORY_GET_STRING_SERIAL:
 695                 src = dev->serial;
 696                 break;
 697         case ACCESSORY_IS_START_REQUESTED:
 698                 return dev->start_requested;
 699         case ACCESSORY_GET_AUDIO_MODE:
 700                 return dev->audio_mode;
 701         }
 702         if (!src)
 703                 return -EINVAL;
 704
 705         ret = strlen(src) + 1;
 706         if (copy_to_user((void __user *)value, src, ret))
 707                 ret = -EFAULT;
 708         return ret;
 709 }
 710
 711 static int acc_open(struct inode *ip, struct file *fp)
 712 {
 713         printk(KERN_INFO "acc_open\n");
 714         if (atomic_xchg(&_acc_dev->open_excl, 1))
 715                 return -EBUSY;
 716
 717         _acc_dev->disconnected = 0;
 718         fp->private_data = _acc_dev;
 719         return 0;
 720 }
 721
 722 static int acc_release(struct inode *ip, struct file *fp)
 723 {
 724         printk(KERN_INFO "acc_release\n");
 725
 726         WARN_ON(!atomic_xchg(&_acc_dev->open_excl, 0));
 727         _acc_dev->disconnected = 0;
 728         return 0;
 729 }
 730
 731 /* file operations for /dev/usb_accessory */
 732 static const struct file_operations acc_fops = {
 733         .owner = THIS_MODULE,
 734         .read = acc_read,
 735         .write = acc_write,
 736         .unlocked_ioctl = acc_ioctl,
 737         .open = acc_open,
 738         .release = acc_release,
 739 };
 740
 741 static int acc_hid_probe(struct hid_device *hdev,
 742                 const struct hid_device_id *id)
 743 {
 744         int ret;
 745
 746         ret = hid_parse(hdev);
 747         if (ret)
 748                 return ret;
 749         return hid_hw_start(hdev, HID_CONNECT_DEFAULT);
 750 }
 751
 752 static struct miscdevice acc_device = {
 753         .minor = MISC_DYNAMIC_MINOR,
 754         .name = "usb_accessory",
 755         .fops = &acc_fops,
 756 };
 757
 758 static const struct hid_device_id acc_hid_table[] = {
 759         { HID_USB_DEVICE(HID_ANY_ID, HID_ANY_ID) },
 760         { }
 761 };
 762
 763 static struct hid_driver acc_hid_driver = {
 764         .name = "USB accessory",
 765         .id_table = acc_hid_table,
 766         .probe = acc_hid_probe,
 767 };
 768
 769 static int acc_ctrlrequest(struct usb_composite_dev *cdev,
 770                                 const struct usb_ctrlrequest *ctrl)
 771 {
 772         struct acc_dev  *dev = _acc_dev;
 773         int     value = -EOPNOTSUPP;
 774         struct acc_hid_dev *hid;
 775         int offset;
 776         u8 b_requestType = ctrl->bRequestType;
 777         u8 b_request = ctrl->bRequest;
 778         u16     w_index = le16_to_cpu(ctrl->wIndex);
 779         u16     w_value = le16_to_cpu(ctrl->wValue);
 780         u16     w_length = le16_to_cpu(ctrl->wLength);
 781         unsigned long flags;
 782
 783 /*
 784         printk(KERN_INFO "acc_ctrlrequest "
 785                         "%02x.%02x v%04x i%04x l%u\n",
 786                         b_requestType, b_request,
 787                         w_value, w_index, w_length);
 788 */
 789
 790         if (b_requestType == (USB_DIR_OUT | USB_TYPE_VENDOR)) {
 791                 if (b_request == ACCESSORY_START) {
 792                         dev->start_requested = 1;
 793                         schedule_delayed_work(
 794                                 &dev->start_work, msecs_to_jiffies(10));
 795                         value = 0;
 796                 } else if (b_request == ACCESSORY_SEND_STRING) {
 797                         dev->string_index = w_index;
 798                         cdev->gadget->ep0->driver_data = dev;
 799                         cdev->req->complete = acc_complete_set_string;
 800                         value = w_length;
 801                 } else if (b_request == ACCESSORY_SET_AUDIO_MODE &&
 802                                 w_index == 0 && w_length == 0) {
 803                         dev->audio_mode = w_value;
 804                         value = 0;
 805                 } else if (b_request == ACCESSORY_REGISTER_HID) {
 806                         value = acc_register_hid(dev, w_value, w_index);
 807                 } else if (b_request == ACCESSORY_UNREGISTER_HID) {
 808                         value = acc_unregister_hid(dev, w_value);
 809                 } else if (b_request == ACCESSORY_SET_HID_REPORT_DESC) {
 810                         spin_lock_irqsave(&dev->lock, flags);
 811                         hid = acc_hid_get(&dev->new_hid_list, w_value);
 812                         spin_unlock_irqrestore(&dev->lock, flags);
 813                         if (!hid) {
 814                                 value = -EINVAL;
 815                                 goto err;
 816                         }
 817                         offset = w_index;
 818                         if (offset != hid->report_desc_offset
 819                                 || offset + w_length > hid->report_desc_len) {
 820                                 value = -EINVAL;
 821                                 goto err;
 822                         }
 823                         cdev->req->context = hid;
 824                         cdev->req->complete = acc_complete_set_hid_report_desc;
 825                         value = w_length;
 826                 } else if (b_request == ACCESSORY_SEND_HID_EVENT) {
 827                         spin_lock_irqsave(&dev->lock, flags);
 828                         hid = acc_hid_get(&dev->hid_list, w_value);
 829                         spin_unlock_irqrestore(&dev->lock, flags);
 830                         if (!hid) {
 831                                 value = -EINVAL;
 832                                 goto err;
 833                         }
 834                         cdev->req->context = hid;
 835                         cdev->req->complete = acc_complete_send_hid_event;
 836                         value = w_length;
 837                 }
 838         } else if (b_requestType == (USB_DIR_IN | USB_TYPE_VENDOR)) {
 839                 if (b_request == ACCESSORY_GET_PROTOCOL) {
 840                         *((u16 *)cdev->req->buf) = PROTOCOL_VERSION;
 841                         value = sizeof(u16);
 842
 843                         /* clear any string left over from a previous session */
 844                         memset(dev->manufacturer, 0, sizeof(dev->manufacturer));
 845                         memset(dev->model, 0, sizeof(dev->model));
 846                         memset(dev->description, 0, sizeof(dev->description));
 847                         memset(dev->version, 0, sizeof(dev->version));
 848                         memset(dev->uri, 0, sizeof(dev->uri));
 849                         memset(dev->serial, 0, sizeof(dev->serial));
 850                         dev->start_requested = 0;
 851                         dev->audio_mode = 0;
 852                 }
 853         }
 854
 855         if (value >= 0) {
 856                 cdev->req->zero = 0;
 857                 cdev->req->length = value;
 858                 value = usb_ep_queue(cdev->gadget->ep0, cdev->req, GFP_ATOMIC);
 859                 if (value < 0)
 860                         ERROR(cdev, "%s setup response queue error\n",
 861                                 __func__);
 862         }
 863
 864 err:
 865         if (value == -EOPNOTSUPP)
 866                 VDBG(cdev,
 867                         "unknown class-specific control req "
 868                         "%02x.%02x v%04x i%04x l%u\n",
 869                         ctrl->bRequestType, ctrl->bRequest,
 870                         w_value, w_index, w_length);
 871         return value;
 872 }
 873
 874 static int
 875 acc_function_bind(struct usb_configuration *c, struct usb_function *f)
 876 {
 877         struct usb_composite_dev *cdev = c->cdev;
 878         struct acc_dev  *dev = func_to_dev(f);
 879         int                     id;
 880         int                     ret;
 881
 882         DBG(cdev, "acc_function_bind dev: %p\n", dev);
 883
 884         ret = hid_register_driver(&acc_hid_driver);
 885         if (ret)
 886                 return ret;
 887
 888         dev->start_requested = 0;
 889
 890         /* allocate interface ID(s) */
 891         id = usb_interface_id(c, f);
 892         if (id < 0)
 893                 return id;
 894         acc_interface_desc.bInterfaceNumber = id;
 895
 896         /* allocate endpoints */
 897         ret = create_bulk_endpoints(dev, &acc_fullspeed_in_desc,
 898                         &acc_fullspeed_out_desc);
 899         if (ret)
 900                 return ret;
 901
 902         /* support high speed hardware */
 903         if (gadget_is_dualspeed(c->cdev->gadget)) {
 904                 acc_highspeed_in_desc.bEndpointAddress =
 905                         acc_fullspeed_in_desc.bEndpointAddress;
 906                 acc_highspeed_out_desc.bEndpointAddress =
 907                         acc_fullspeed_out_desc.bEndpointAddress;
 908         }
 909
 910         DBG(cdev, "%s speed %s: IN/%s, OUT/%s\n",
 911                         gadget_is_dualspeed(c->cdev->gadget) ? "dual" : "full",
 912                         f->name, dev->ep_in->name, dev->ep_out->name);
 913         return 0;
 914 }
 915
 916 static void
 917 kill_all_hid_devices(struct acc_dev *dev)
 918 {
 919         struct acc_hid_dev *hid;
 920         struct list_head *entry, *temp;
 921         unsigned long flags;
 922
 923         spin_lock_irqsave(&dev->lock, flags);
 924         list_for_each_safe(entry, temp, &dev->hid_list) {
 925                 hid = list_entry(entry, struct acc_hid_dev, list);
 926                 list_del(&hid->list);
 927                 list_add(&hid->list, &dev->dead_hid_list);
 928         }
 929         list_for_each_safe(entry, temp, &dev->new_hid_list) {
 930                 hid = list_entry(entry, struct acc_hid_dev, list);
 931                 list_del(&hid->list);
 932                 list_add(&hid->list, &dev->dead_hid_list);
 933         }
 934         spin_unlock_irqrestore(&dev->lock, flags);
 935
 936         schedule_work(&dev->hid_work);
 937 }
 938
 939 static void
 940 acc_hid_unbind(struct acc_dev *dev)
 941 {
 942         hid_unregister_driver(&acc_hid_driver);
 943         kill_all_hid_devices(dev);
 944 }
 945
 946 static void
 947 acc_function_unbind(struct usb_configuration *c, struct usb_function *f)
 948 {
 949         struct acc_dev  *dev = func_to_dev(f);
 950         struct usb_request *req;
 951         int i;
 952
 953         while ((req = req_get(dev, &dev->tx_idle)))
 954                 acc_request_free(req, dev->ep_in);
 955         for (i = 0; i < RX_REQ_MAX; i++)
 956                 acc_request_free(dev->rx_req[i], dev->ep_out);
 957
 958         acc_hid_unbind(dev);
 959 }
 960
 961 static void acc_start_work(struct work_struct *data)
 962 {
 963         char *envp[2] = { "ACCESSORY=START", NULL };
 964         kobject_uevent_env(&acc_device.this_device->kobj, KOBJ_CHANGE, envp);
 965 }
 966
 967 static int acc_hid_init(struct acc_hid_dev *hdev)
 968 {
 969         struct hid_device *hid;
 970         int ret;
 971
 972         hid = hid_allocate_device();
 973         if (IS_ERR(hid))
 974                 return PTR_ERR(hid);
 975
 976         hid->ll_driver = &acc_hid_ll_driver;
 977         hid->dev.parent = acc_device.this_device;
 978
 979         hid->bus = BUS_USB;
 980         hid->vendor = HID_ANY_ID;
 981         hid->product = HID_ANY_ID;
 982         hid->driver_data = hdev;
 983         ret = hid_add_device(hid);
 984         if (ret) {
 985                 pr_err("can't add hid device: %d\n", ret);
 986                 hid_destroy_device(hid);
 987                 return ret;
 988         }
 989
 990         hdev->hid = hid;
 991         return 0;
 992 }
 993
 994 static void acc_hid_delete(struct acc_hid_dev *hid)
 995 {
 996         kfree(hid->report_desc);
 997         kfree(hid);
 998 }
 999
1000 static void acc_hid_work(struct work_struct *data)
1001 {
1002         struct acc_dev *dev = _acc_dev;
1003         struct list_head        *entry, *temp;
1004         struct acc_hid_dev *hid;
1005         struct list_head        new_list, dead_list;
1006         unsigned long flags;
1007
1008         INIT_LIST_HEAD(&new_list);
1009
1010         spin_lock_irqsave(&dev->lock, flags);
1011
1012         /* copy hids that are ready for initialization to new_list */
1013         list_for_each_safe(entry, temp, &dev->new_hid_list) {
1014                 hid = list_entry(entry, struct acc_hid_dev, list);
1015                 if (hid->report_desc_offset == hid->report_desc_len)
1016                         list_move(&hid->list, &new_list);
1017         }
1018
1019         if (list_empty(&dev->dead_hid_list)) {
1020                 INIT_LIST_HEAD(&dead_list);
1021         } else {
1022                 /* move all of dev->dead_hid_list to dead_list */
1023                 dead_list.prev = dev->dead_hid_list.prev;
1024                 dead_list.next = dev->dead_hid_list.next;
1025                 dead_list.next->prev = &dead_list;
1026                 dead_list.prev->next = &dead_list;
1027                 INIT_LIST_HEAD(&dev->dead_hid_list);
1028         }
1029
1030         spin_unlock_irqrestore(&dev->lock, flags);
1031
1032         /* register new HID devices */
1033         list_for_each_safe(entry, temp, &new_list) {
1034                 hid = list_entry(entry, struct acc_hid_dev, list);
1035                 if (acc_hid_init(hid)) {
1036                         pr_err("can't add HID device %p\n", hid);
1037                         acc_hid_delete(hid);
1038                 } else {
1039                         spin_lock_irqsave(&dev->lock, flags);
1040                         list_move(&hid->list, &dev->hid_list);
1041                         spin_unlock_irqrestore(&dev->lock, flags);
1042                 }
1043         }
1044
1045         /* remove dead HID devices */
1046         list_for_each_safe(entry, temp, &dead_list) {
1047                 hid = list_entry(entry, struct acc_hid_dev, list);
1048                 list_del(&hid->list);
1049                 if (hid->hid)
1050                         hid_destroy_device(hid->hid);
1051                 acc_hid_delete(hid);
1052         }
1053 }
1054
1055 static int acc_function_set_alt(struct usb_function *f,
1056                 unsigned intf, unsigned alt)
1057 {
1058         struct acc_dev  *dev = func_to_dev(f);
1059         struct usb_composite_dev *cdev = f->config->cdev;
1060         int ret;
1061
1062         DBG(cdev, "acc_function_set_alt intf: %d alt: %d\n", intf, alt);
1063
1064         ret = config_ep_by_speed(cdev->gadget, f, dev->ep_in);
1065         if (ret)
1066                 return ret;
1067
1068         ret = usb_ep_enable(dev->ep_in);
1069         if (ret)
1070                 return ret;
1071
1072         ret = config_ep_by_speed(cdev->gadget, f, dev->ep_out);
1073         if (ret)
1074                 return ret;
1075
1076         ret = usb_ep_enable(dev->ep_out);
1077         if (ret) {
1078                 usb_ep_disable(dev->ep_in);
1079                 return ret;
1080         }
1081
1082         dev->online = 1;
1083
1084         /* readers may be blocked waiting for us to go online */
1085         wake_up(&dev->read_wq);
1086         return 0;
1087 }
1088
1089 static void acc_function_disable(struct usb_function *f)
1090 {
1091         struct acc_dev  *dev = func_to_dev(f);
1092         struct usb_composite_dev        *cdev = dev->cdev;
1093
1094         DBG(cdev, "acc_function_disable\n");
1095         acc_set_disconnected(dev);
1096         usb_ep_disable(dev->ep_in);
1097         usb_ep_disable(dev->ep_out);
1098
1099         /* readers may be blocked waiting for us to go online */
1100         wake_up(&dev->read_wq);
1101
1102         VDBG(cdev, "%s disabled\n", dev->function.name);
1103 }
1104
1105 static int acc_bind_config(struct usb_configuration *c)
1106 {
1107         struct acc_dev *dev = _acc_dev;
1108         int ret;
1109
1110         printk(KERN_INFO "acc_bind_config\n");
1111
1112         /* allocate a string ID for our interface */
1113         if (acc_string_defs[INTERFACE_STRING_INDEX].id == 0) {
1114                 ret = usb_string_id(c->cdev);
1115                 if (ret < 0)
1116                         return ret;
1117                 acc_string_defs[INTERFACE_STRING_INDEX].id = ret;
1118                 acc_interface_desc.iInterface = ret;
1119         }
1120
1121         dev->cdev = c->cdev;
1122         dev->function.name = "accessory";
1123         dev->function.strings = acc_strings,
1124         dev->function.descriptors = fs_acc_descs;
1125         dev->function.hs_descriptors = hs_acc_descs;
1126         dev->function.bind = acc_function_bind;
1127         dev->function.unbind = acc_function_unbind;
1128         dev->function.set_alt = acc_function_set_alt;
1129         dev->function.disable = acc_function_disable;
1130
1131         return usb_add_function(c, &dev->function);
1132 }
1133
1134 static int acc_setup(void)
1135 {
1136         struct acc_dev *dev;
1137         int ret;
1138
1139         dev = kzalloc(sizeof(*dev), GFP_KERNEL);
1140         if (!dev)
1141                 return -ENOMEM;
1142
1143         spin_lock_init(&dev->lock);
1144         init_waitqueue_head(&dev->read_wq);
1145         init_waitqueue_head(&dev->write_wq);
1146         atomic_set(&dev->open_excl, 0);
1147         INIT_LIST_HEAD(&dev->tx_idle);
1148         INIT_LIST_HEAD(&dev->hid_list);
1149         INIT_LIST_HEAD(&dev->new_hid_list);
1150         INIT_LIST_HEAD(&dev->dead_hid_list);
1151         INIT_DELAYED_WORK(&dev->start_work, acc_start_work);
1152         INIT_WORK(&dev->hid_work, acc_hid_work);
1153
1154         /* _acc_dev must be set before calling usb_gadget_register_driver */
1155         _acc_dev = dev;
1156
1157         ret = misc_register(&acc_device);
1158         if (ret)
1159                 goto err;
1160
1161         return 0;
1162
1163 err:
1164         kfree(dev);
1165         pr_err("USB accessory gadget driver failed to initialize\n");
1166         return ret;
1167 }
1168
1169 static void acc_disconnect(void)
1170 {
1171         /* unregister all HID devices if USB is disconnected */
1172         kill_all_hid_devices(_acc_dev);
1173 }
1174
1175 static void acc_cleanup(void)
1176 {
1177         misc_deregister(&acc_device);
1178         kfree(_acc_dev);
1179         _acc_dev = NULL;
1180 }