drivers/usb/gadget/function/f_hid.c

   1 /*
   2  * f_hid.c -- USB HID function driver
   3  *
   4  * Copyright (C) 2010 Fabien Chouteau <fabien.chouteau@barco.com>
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 2 of the License, or
   9  * (at your option) any later version.
  10  */
  11
  12 #include <linux/kernel.h>
  13 #include <linux/module.h>
  14 #include <linux/hid.h>
  15 #include <linux/idr.h>
  16 #include <linux/cdev.h>
  17 #include <linux/mutex.h>
  18 #include <linux/poll.h>
  19 #include <linux/uaccess.h>
  20 #include <linux/wait.h>
  21 #include <linux/sched.h>
  22 #include <linux/usb/g_hid.h>
  23
  24 #include "u_f.h"
  25 #include "u_hid.h"
  26
  27 #define HIDG_MINORS     4
  28
  29 static int major, minors;
  30 static struct class *hidg_class;
  31 static DEFINE_IDA(hidg_ida);
  32 static DEFINE_MUTEX(hidg_ida_lock); /* protects access to hidg_ida */
  33
  34 /*-------------------------------------------------------------------------*/
  35 /*                            HID gadget struct                            */
  36
  37 struct f_hidg_req_list {
  38         struct usb_request      *req;
  39         unsigned int            pos;
  40         struct list_head        list;
  41 };
  42
  43 struct f_hidg {
  44         /* configuration */
  45         unsigned char                   bInterfaceSubClass;
  46         unsigned char                   bInterfaceProtocol;
  47         unsigned short                  report_desc_length;
  48         char                            *report_desc;
  49         unsigned short                  report_length;
  50
  51         /* recv report */
  52         struct list_head                completed_out_req;
  53         spinlock_t                      spinlock;
  54         wait_queue_head_t               read_queue;
  55         unsigned int                    qlen;
  56
  57         /* send report */
  58         struct mutex                    lock;
  59         bool                            write_pending;
  60         wait_queue_head_t               write_queue;
  61         struct usb_request              *req;
  62
  63         int                             minor;
  64         struct cdev                     cdev;
  65         struct usb_function             func;
  66
  67         struct usb_ep                   *in_ep;
  68         struct usb_ep                   *out_ep;
  69 };
  70
  71 static inline struct f_hidg *func_to_hidg(struct usb_function *f)
  72 {
  73         return container_of(f, struct f_hidg, func);
  74 }
  75
  76 /*-------------------------------------------------------------------------*/
  77 /*                           Static descriptors                            */
  78
  79 static struct usb_interface_descriptor hidg_interface_desc = {
  80         .bLength                = sizeof hidg_interface_desc,
  81         .bDescriptorType        = USB_DT_INTERFACE,
  82         /* .bInterfaceNumber    = DYNAMIC */
  83         .bAlternateSetting      = 0,
  84         .bNumEndpoints          = 2,
  85         .bInterfaceClass        = USB_CLASS_HID,
  86         /* .bInterfaceSubClass  = DYNAMIC */
  87         /* .bInterfaceProtocol  = DYNAMIC */
  88         /* .iInterface          = DYNAMIC */
  89 };
  90
  91 static struct hid_descriptor hidg_desc = {
  92         .bLength                        = sizeof hidg_desc,
  93         .bDescriptorType                = HID_DT_HID,
  94         .bcdHID                         = 0x0101,
  95         .bCountryCode                   = 0x00,
  96         .bNumDescriptors                = 0x1,
  97         /*.desc[0].bDescriptorType      = DYNAMIC */
  98         /*.desc[0].wDescriptorLenght    = DYNAMIC */
  99 };
 100
 101 /* High-Speed Support */
 102
 103 static struct usb_endpoint_descriptor hidg_hs_in_ep_desc = {
 104         .bLength                = USB_DT_ENDPOINT_SIZE,
 105         .bDescriptorType        = USB_DT_ENDPOINT,
 106         .bEndpointAddress       = USB_DIR_IN,
 107         .bmAttributes           = USB_ENDPOINT_XFER_INT,
 108         /*.wMaxPacketSize       = DYNAMIC */
 109         .bInterval              = 4, /* FIXME: Add this field in the
 110                                       * HID gadget configuration?
 111                                       * (struct hidg_func_descriptor)
 112                                       */
 113 };
 114
 115 static struct usb_endpoint_descriptor hidg_hs_out_ep_desc = {
 116         .bLength                = USB_DT_ENDPOINT_SIZE,
 117         .bDescriptorType        = USB_DT_ENDPOINT,
 118         .bEndpointAddress       = USB_DIR_OUT,
 119         .bmAttributes           = USB_ENDPOINT_XFER_INT,
 120         /*.wMaxPacketSize       = DYNAMIC */
 121         .bInterval              = 4, /* FIXME: Add this field in the
 122                                       * HID gadget configuration?
 123                                       * (struct hidg_func_descriptor)
 124                                       */
 125 };
 126
 127 static struct usb_descriptor_header *hidg_hs_descriptors[] = {
 128         (struct usb_descriptor_header *)&hidg_interface_desc,
 129         (struct usb_descriptor_header *)&hidg_desc,
 130         (struct usb_descriptor_header *)&hidg_hs_in_ep_desc,
 131         (struct usb_descriptor_header *)&hidg_hs_out_ep_desc,
 132         NULL,
 133 };
 134
 135 /* Full-Speed Support */
 136
 137 static struct usb_endpoint_descriptor hidg_fs_in_ep_desc = {
 138         .bLength                = USB_DT_ENDPOINT_SIZE,
 139         .bDescriptorType        = USB_DT_ENDPOINT,
 140         .bEndpointAddress       = USB_DIR_IN,
 141         .bmAttributes           = USB_ENDPOINT_XFER_INT,
 142         /*.wMaxPacketSize       = DYNAMIC */
 143         .bInterval              = 10, /* FIXME: Add this field in the
 144                                        * HID gadget configuration?
 145                                        * (struct hidg_func_descriptor)
 146                                        */
 147 };
 148
 149 static struct usb_endpoint_descriptor hidg_fs_out_ep_desc = {
 150         .bLength                = USB_DT_ENDPOINT_SIZE,
 151         .bDescriptorType        = USB_DT_ENDPOINT,
 152         .bEndpointAddress       = USB_DIR_OUT,
 153         .bmAttributes           = USB_ENDPOINT_XFER_INT,
 154         /*.wMaxPacketSize       = DYNAMIC */
 155         .bInterval              = 10, /* FIXME: Add this field in the
 156                                        * HID gadget configuration?
 157                                        * (struct hidg_func_descriptor)
 158                                        */
 159 };
 160
 161 static struct usb_descriptor_header *hidg_fs_descriptors[] = {
 162         (struct usb_descriptor_header *)&hidg_interface_desc,
 163         (struct usb_descriptor_header *)&hidg_desc,
 164         (struct usb_descriptor_header *)&hidg_fs_in_ep_desc,
 165         (struct usb_descriptor_header *)&hidg_fs_out_ep_desc,
 166         NULL,
 167 };
 168
 169 /*-------------------------------------------------------------------------*/
 170 /*                                 Strings                                 */
 171
 172 #define CT_FUNC_HID_IDX 0
 173
 174 static struct usb_string ct_func_string_defs[] = {
 175         [CT_FUNC_HID_IDX].s     = "HID Interface",
 176         {},                     /* end of list */
 177 };
 178
 179 static struct usb_gadget_strings ct_func_string_table = {
 180         .language       = 0x0409,       /* en-US */
 181         .strings        = ct_func_string_defs,
 182 };
 183
 184 static struct usb_gadget_strings *ct_func_strings[] = {
 185         &ct_func_string_table,
 186         NULL,
 187 };
 188
 189 /*-------------------------------------------------------------------------*/
 190 /*                              Char Device                                */
 191
 192 static ssize_t f_hidg_read(struct file *file, char __user *buffer,
 193                         size_t count, loff_t *ptr)
 194 {
 195         struct f_hidg *hidg = file->private_data;
 196         struct f_hidg_req_list *list;
 197         struct usb_request *req;
 198         unsigned long flags;
 199         int ret;
 200
 201         if (!count)
 202                 return 0;
 203
 204         if (!access_ok(VERIFY_WRITE, buffer, count))
 205                 return -EFAULT;
 206
 207         spin_lock_irqsave(&hidg->spinlock, flags);
 208
 209 #define READ_COND (!list_empty(&hidg->completed_out_req))
 210
 211         /* wait for at least one buffer to complete */
 212         while (!READ_COND) {
 213                 spin_unlock_irqrestore(&hidg->spinlock, flags);
 214                 if (file->f_flags & O_NONBLOCK)
 215                         return -EAGAIN;
 216
 217                 if (wait_event_interruptible(hidg->read_queue, READ_COND))
 218                         return -ERESTARTSYS;
 219
 220                 spin_lock_irqsave(&hidg->spinlock, flags);
 221         }
 222
 223         /* pick the first one */
 224         list = list_first_entry(&hidg->completed_out_req,
 225                                 struct f_hidg_req_list, list);
 226         req = list->req;
 227         count = min_t(unsigned int, count, req->actual - list->pos);
 228         spin_unlock_irqrestore(&hidg->spinlock, flags);
 229
 230         /* copy to user outside spinlock */
 231         count -= copy_to_user(buffer, req->buf + list->pos, count);
 232         list->pos += count;
 233
 234         /*
 235          * if this request is completely handled and transfered to
 236          * userspace, remove its entry from the list and requeue it
 237          * again. Otherwise, we will revisit it again upon the next
 238          * call, taking into account its current read position.
 239          */
 240         if (list->pos == req->actual) {
 241                 spin_lock_irqsave(&hidg->spinlock, flags);
 242                 list_del(&list->list);
 243                 kfree(list);
 244                 spin_unlock_irqrestore(&hidg->spinlock, flags);
 245
 246                 req->length = hidg->report_length;
 247                 ret = usb_ep_queue(hidg->out_ep, req, GFP_KERNEL);
 248                 if (ret < 0)
 249                         return ret;
 250         }
 251
 252         return count;
 253 }
 254
 255 static void f_hidg_req_complete(struct usb_ep *ep, struct usb_request *req)
 256 {
 257         struct f_hidg *hidg = (struct f_hidg *)ep->driver_data;
 258
 259         if (req->status != 0) {
 260                 ERROR(hidg->func.config->cdev,
 261                         "End Point Request ERROR: %d\n", req->status);
 262         }
 263
 264         hidg->write_pending = 0;
 265         wake_up(&hidg->write_queue);
 266 }
 267
 268 static ssize_t f_hidg_write(struct file *file, const char __user *buffer,
 269                             size_t count, loff_t *offp)
 270 {
 271         struct f_hidg *hidg  = file->private_data;
 272         ssize_t status = -ENOMEM;
 273
 274         if (!access_ok(VERIFY_READ, buffer, count))
 275                 return -EFAULT;
 276
 277         mutex_lock(&hidg->lock);
 278
 279 #define WRITE_COND (!hidg->write_pending)
 280
 281         /* write queue */
 282         while (!WRITE_COND) {
 283                 mutex_unlock(&hidg->lock);
 284                 if (file->f_flags & O_NONBLOCK)
 285                         return -EAGAIN;
 286
 287                 if (wait_event_interruptible_exclusive(
 288                                 hidg->write_queue, WRITE_COND))
 289                         return -ERESTARTSYS;
 290
 291                 mutex_lock(&hidg->lock);
 292         }
 293
 294         count  = min_t(unsigned, count, hidg->report_length);
 295         status = copy_from_user(hidg->req->buf, buffer, count);
 296
 297         if (status != 0) {
 298                 ERROR(hidg->func.config->cdev,
 299                         "copy_from_user error\n");
 300                 mutex_unlock(&hidg->lock);
 301                 return -EINVAL;
 302         }
 303
 304         hidg->req->status   = 0;
 305         hidg->req->zero     = 0;
 306         hidg->req->length   = count;
 307         hidg->req->complete = f_hidg_req_complete;
 308         hidg->req->context  = hidg;
 309         hidg->write_pending = 1;
 310
 311         status = usb_ep_queue(hidg->in_ep, hidg->req, GFP_ATOMIC);
 312         if (status < 0) {
 313                 ERROR(hidg->func.config->cdev,
 314                         "usb_ep_queue error on int endpoint %zd\n", status);
 315                 hidg->write_pending = 0;
 316                 wake_up(&hidg->write_queue);
 317         } else {
 318                 status = count;
 319         }
 320
 321         mutex_unlock(&hidg->lock);
 322
 323         return status;
 324 }
 325
 326 static unsigned int f_hidg_poll(struct file *file, poll_table *wait)
 327 {
 328         struct f_hidg   *hidg  = file->private_data;
 329         unsigned int    ret = 0;
 330
 331         poll_wait(file, &hidg->read_queue, wait);
 332         poll_wait(file, &hidg->write_queue, wait);
 333
 334         if (WRITE_COND)
 335                 ret |= POLLOUT | POLLWRNORM;
 336
 337         if (READ_COND)
 338                 ret |= POLLIN | POLLRDNORM;
 339
 340         return ret;
 341 }
 342
 343 #undef WRITE_COND
 344 #undef READ_COND
 345
 346 static int f_hidg_release(struct inode *inode, struct file *fd)
 347 {
 348         fd->private_data = NULL;
 349         return 0;
 350 }
 351
 352 static int f_hidg_open(struct inode *inode, struct file *fd)
 353 {
 354         struct f_hidg *hidg =
 355                 container_of(inode->i_cdev, struct f_hidg, cdev);
 356
 357         fd->private_data = hidg;
 358
 359         return 0;
 360 }
 361
 362 /*-------------------------------------------------------------------------*/
 363 /*                                usb_function                             */
 364
 365 static inline struct usb_request *hidg_alloc_ep_req(struct usb_ep *ep,
 366                                                     unsigned length)
 367 {
 368         return alloc_ep_req(ep, length, length);
 369 }
 370
 371 static void hidg_set_report_complete(struct usb_ep *ep, struct usb_request *req)
 372 {
 373         struct f_hidg *hidg = (struct f_hidg *) req->context;
 374         struct f_hidg_req_list *req_list;
 375         unsigned long flags;
 376
 377         req_list = kzalloc(sizeof(*req_list), GFP_ATOMIC);
 378         if (!req_list)
 379                 return;
 380
 381         req_list->req = req;
 382
 383         spin_lock_irqsave(&hidg->spinlock, flags);
 384         list_add_tail(&req_list->list, &hidg->completed_out_req);
 385         spin_unlock_irqrestore(&hidg->spinlock, flags);
 386
 387         wake_up(&hidg->read_queue);
 388 }
 389
 390 static int hidg_setup(struct usb_function *f,
 391                 const struct usb_ctrlrequest *ctrl)
 392 {
 393         struct f_hidg                   *hidg = func_to_hidg(f);
 394         struct usb_composite_dev        *cdev = f->config->cdev;
 395         struct usb_request              *req  = cdev->req;
 396         int status = 0;
 397         __u16 value, length;
 398
 399         value   = __le16_to_cpu(ctrl->wValue);
 400         length  = __le16_to_cpu(ctrl->wLength);
 401
 402         VDBG(cdev,
 403              "%s crtl_request : bRequestType:0x%x bRequest:0x%x Value:0x%x\n",
 404              __func__, ctrl->bRequestType, ctrl->bRequest, value);
 405
 406         switch ((ctrl->bRequestType << 8) | ctrl->bRequest) {
 407         case ((USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8
 408                   | HID_REQ_GET_REPORT):
 409                 VDBG(cdev, "get_report\n");
 410
 411                 /* send an empty report */
 412                 length = min_t(unsigned, length, hidg->report_length);
 413                 memset(req->buf, 0x0, length);
 414
 415                 goto respond;
 416                 break;
 417
 418         case ((USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8
 419                   | HID_REQ_GET_PROTOCOL):
 420                 VDBG(cdev, "get_protocol\n");
 421                 goto stall;
 422                 break;
 423
 424         case ((USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8
 425                   | HID_REQ_SET_REPORT):
 426                 VDBG(cdev, "set_report | wLength=%d\n", ctrl->wLength);
 427                 goto stall;
 428                 break;
 429
 430         case ((USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8
 431                   | HID_REQ_SET_PROTOCOL):
 432                 VDBG(cdev, "set_protocol\n");
 433                 goto stall;
 434                 break;
 435
 436         case ((USB_DIR_IN | USB_TYPE_STANDARD | USB_RECIP_INTERFACE) << 8
 437                   | USB_REQ_GET_DESCRIPTOR):
 438                 switch (value >> 8) {
 439                 case HID_DT_HID:
 440                 {
 441                         struct hid_descriptor hidg_desc_copy = hidg_desc;
 442
 443                         VDBG(cdev, "USB_REQ_GET_DESCRIPTOR: HID\n");
 444                         hidg_desc_copy.desc[0].bDescriptorType = HID_DT_REPORT;
 445                         hidg_desc_copy.desc[0].wDescriptorLength =
 446                                 cpu_to_le16(hidg->report_desc_length);
 447
 448                         length = min_t(unsigned short, length,
 449                                                    hidg_desc_copy.bLength);
 450                         memcpy(req->buf, &hidg_desc_copy, length);
 451                         goto respond;
 452                         break;
 453                 }
 454                 case HID_DT_REPORT:
 455                         VDBG(cdev, "USB_REQ_GET_DESCRIPTOR: REPORT\n");
 456                         length = min_t(unsigned short, length,
 457                                                    hidg->report_desc_length);
 458                         memcpy(req->buf, hidg->report_desc, length);
 459                         goto respond;
 460                         break;
 461
 462                 default:
 463                         VDBG(cdev, "Unknown descriptor request 0x%x\n",
 464                                  value >> 8);
 465                         goto stall;
 466                         break;
 467                 }
 468                 break;
 469
 470         default:
 471                 VDBG(cdev, "Unknown request 0x%x\n",
 472                          ctrl->bRequest);
 473                 goto stall;
 474                 break;
 475         }
 476
 477 stall:
 478         return -EOPNOTSUPP;
 479
 480 respond:
 481         req->zero = 0;
 482         req->length = length;
 483         status = usb_ep_queue(cdev->gadget->ep0, req, GFP_ATOMIC);
 484         if (status < 0)
 485                 ERROR(cdev, "usb_ep_queue error on ep0 %d\n", value);
 486         return status;
 487 }
 488
 489 static void hidg_disable(struct usb_function *f)
 490 {
 491         struct f_hidg *hidg = func_to_hidg(f);
 492         struct f_hidg_req_list *list, *next;
 493
 494         usb_ep_disable(hidg->in_ep);
 495         usb_ep_disable(hidg->out_ep);
 496
 497         list_for_each_entry_safe(list, next, &hidg->completed_out_req, list) {
 498                 list_del(&list->list);
 499                 kfree(list);
 500         }
 501 }
 502
 503 static int hidg_set_alt(struct usb_function *f, unsigned intf, unsigned alt)
 504 {
 505         struct usb_composite_dev                *cdev = f->config->cdev;
 506         struct f_hidg                           *hidg = func_to_hidg(f);
 507         int i, status = 0;
 508
 509         VDBG(cdev, "hidg_set_alt intf:%d alt:%d\n", intf, alt);
 510
 511         if (hidg->in_ep != NULL) {
 512                 /* restart endpoint */
 513                 usb_ep_disable(hidg->in_ep);
 514
 515                 status = config_ep_by_speed(f->config->cdev->gadget, f,
 516                                             hidg->in_ep);
 517                 if (status) {
 518                         ERROR(cdev, "config_ep_by_speed FAILED!\n");
 519                         goto fail;
 520                 }
 521                 status = usb_ep_enable(hidg->in_ep);
 522                 if (status < 0) {
 523                         ERROR(cdev, "Enable IN endpoint FAILED!\n");
 524                         goto fail;
 525                 }
 526                 hidg->in_ep->driver_data = hidg;
 527         }
 528
 529
 530         if (hidg->out_ep != NULL) {
 531                 /* restart endpoint */
 532                 usb_ep_disable(hidg->out_ep);
 533
 534                 status = config_ep_by_speed(f->config->cdev->gadget, f,
 535                                             hidg->out_ep);
 536                 if (status) {
 537                         ERROR(cdev, "config_ep_by_speed FAILED!\n");
 538                         goto fail;
 539                 }
 540                 status = usb_ep_enable(hidg->out_ep);
 541                 if (status < 0) {
 542                         ERROR(cdev, "Enable IN endpoint FAILED!\n");
 543                         goto fail;
 544                 }
 545                 hidg->out_ep->driver_data = hidg;
 546
 547                 /*
 548                  * allocate a bunch of read buffers and queue them all at once.
 549                  */
 550                 for (i = 0; i < hidg->qlen && status == 0; i++) {
 551                         struct usb_request *req =
 552                                         hidg_alloc_ep_req(hidg->out_ep,
 553                                                           hidg->report_length);
 554                         if (req) {
 555                                 req->complete = hidg_set_report_complete;
 556                                 req->context  = hidg;
 557                                 status = usb_ep_queue(hidg->out_ep, req,
 558                                                       GFP_ATOMIC);
 559                                 if (status)
 560                                         ERROR(cdev, "%s queue req --> %d\n",
 561                                                 hidg->out_ep->name, status);
 562                         } else {
 563                                 usb_ep_disable(hidg->out_ep);
 564                                 status = -ENOMEM;
 565                                 goto fail;
 566                         }
 567                 }
 568         }
 569
 570 fail:
 571         return status;
 572 }
 573
 574 static const struct file_operations f_hidg_fops = {
 575         .owner          = THIS_MODULE,
 576         .open           = f_hidg_open,
 577         .release        = f_hidg_release,
 578         .write          = f_hidg_write,
 579         .read           = f_hidg_read,
 580         .poll           = f_hidg_poll,
 581         .llseek         = noop_llseek,
 582 };
 583
 584 static int hidg_bind(struct usb_configuration *c, struct usb_function *f)
 585 {
 586         struct usb_ep           *ep;
 587         struct f_hidg           *hidg = func_to_hidg(f);
 588         struct usb_string       *us;
 589         struct device           *device;
 590         int                     status;
 591         dev_t                   dev;
 592
 593         /* maybe allocate device-global string IDs, and patch descriptors */
 594         us = usb_gstrings_attach(c->cdev, ct_func_strings,
 595                                  ARRAY_SIZE(ct_func_string_defs));
 596         if (IS_ERR(us))
 597                 return PTR_ERR(us);
 598         hidg_interface_desc.iInterface = us[CT_FUNC_HID_IDX].id;
 599
 600         /* allocate instance-specific interface IDs, and patch descriptors */
 601         status = usb_interface_id(c, f);
 602         if (status < 0)
 603                 goto fail;
 604         hidg_interface_desc.bInterfaceNumber = status;
 605
 606         /* allocate instance-specific endpoints */
 607         status = -ENODEV;
 608         ep = usb_ep_autoconfig(c->cdev->gadget, &hidg_fs_in_ep_desc);
 609         if (!ep)
 610                 goto fail;
 611         hidg->in_ep = ep;
 612
 613         ep = usb_ep_autoconfig(c->cdev->gadget, &hidg_fs_out_ep_desc);
 614         if (!ep)
 615                 goto fail;
 616         hidg->out_ep = ep;
 617
 618         /* preallocate request and buffer */
 619         status = -ENOMEM;
 620         hidg->req = usb_ep_alloc_request(hidg->in_ep, GFP_KERNEL);
 621         if (!hidg->req)
 622                 goto fail;
 623
 624         hidg->req->buf = kmalloc(hidg->report_length, GFP_KERNEL);
 625         if (!hidg->req->buf)
 626                 goto fail;
 627
 628         /* set descriptor dynamic values */
 629         hidg_interface_desc.bInterfaceSubClass = hidg->bInterfaceSubClass;
 630         hidg_interface_desc.bInterfaceProtocol = hidg->bInterfaceProtocol;
 631         hidg_hs_in_ep_desc.wMaxPacketSize = cpu_to_le16(hidg->report_length);
 632         hidg_fs_in_ep_desc.wMaxPacketSize = cpu_to_le16(hidg->report_length);
 633         hidg_hs_out_ep_desc.wMaxPacketSize = cpu_to_le16(hidg->report_length);
 634         hidg_fs_out_ep_desc.wMaxPacketSize = cpu_to_le16(hidg->report_length);
 635         /*
 636          * We can use hidg_desc struct here but we should not relay
 637          * that its content won't change after returning from this function.
 638          */
 639         hidg_desc.desc[0].bDescriptorType = HID_DT_REPORT;
 640         hidg_desc.desc[0].wDescriptorLength =
 641                 cpu_to_le16(hidg->report_desc_length);
 642
 643         hidg_hs_in_ep_desc.bEndpointAddress =
 644                 hidg_fs_in_ep_desc.bEndpointAddress;
 645         hidg_hs_out_ep_desc.bEndpointAddress =
 646                 hidg_fs_out_ep_desc.bEndpointAddress;
 647
 648         status = usb_assign_descriptors(f, hidg_fs_descriptors,
 649                         hidg_hs_descriptors, NULL, NULL);
 650         if (status)
 651                 goto fail;
 652
 653         mutex_init(&hidg->lock);
 654         spin_lock_init(&hidg->spinlock);
 655         init_waitqueue_head(&hidg->write_queue);
 656         init_waitqueue_head(&hidg->read_queue);
 657         INIT_LIST_HEAD(&hidg->completed_out_req);
 658
 659         /* create char device */
 660         cdev_init(&hidg->cdev, &f_hidg_fops);
 661         dev = MKDEV(major, hidg->minor);
 662         status = cdev_add(&hidg->cdev, dev, 1);
 663         if (status)
 664                 goto fail_free_descs;
 665
 666         device = device_create(hidg_class, NULL, dev, NULL,
 667                                "%s%d", "hidg", hidg->minor);
 668         if (IS_ERR(device)) {
 669                 status = PTR_ERR(device);
 670                 goto del;
 671         }
 672
 673         return 0;
 674 del:
 675         cdev_del(&hidg->cdev);
 676 fail_free_descs:
 677         usb_free_all_descriptors(f);
 678 fail:
 679         ERROR(f->config->cdev, "hidg_bind FAILED\n");
 680         if (hidg->req != NULL) {
 681                 kfree(hidg->req->buf);
 682                 if (hidg->in_ep != NULL)
 683                         usb_ep_free_request(hidg->in_ep, hidg->req);
 684         }
 685
 686         return status;
 687 }
 688
 689 static inline int hidg_get_minor(void)
 690 {
 691         int ret;
 692
 693         ret = ida_simple_get(&hidg_ida, 0, 0, GFP_KERNEL);
 694         if (ret >= HIDG_MINORS) {
 695                 ida_simple_remove(&hidg_ida, ret);
 696                 ret = -ENODEV;
 697         }
 698
 699         return ret;
 700 }
 701
 702 static inline struct f_hid_opts *to_f_hid_opts(struct config_item *item)
 703 {
 704         return container_of(to_config_group(item), struct f_hid_opts,
 705                             func_inst.group);
 706 }
 707
 708 static void hid_attr_release(struct config_item *item)
 709 {
 710         struct f_hid_opts *opts = to_f_hid_opts(item);
 711
 712         usb_put_function_instance(&opts->func_inst);
 713 }
 714
 715 static struct configfs_item_operations hidg_item_ops = {
 716         .release        = hid_attr_release,
 717 };
 718
 719 #define F_HID_OPT(name, prec, limit)                                    \
 720 static ssize_t f_hid_opts_##name##_show(struct config_item *item, char *page)\
 721 {                                                                       \
 722         struct f_hid_opts *opts = to_f_hid_opts(item);                  \
 723         int result;                                                     \
 724                                                                         \
 725         mutex_lock(&opts->lock);                                        \
 726         result = sprintf(page, "%d\n", opts->name);                     \
 727         mutex_unlock(&opts->lock);                                      \
 728                                                                         \
 729         return result;                                                  \
 730 }                                                                       \
 731                                                                         \
 732 static ssize_t f_hid_opts_##name##_store(struct config_item *item,      \
 733                                          const char *page, size_t len)  \
 734 {                                                                       \
 735         struct f_hid_opts *opts = to_f_hid_opts(item);                  \
 736         int ret;                                                        \
 737         u##prec num;                                                    \
 738                                                                         \
 739         mutex_lock(&opts->lock);                                        \
 740         if (opts->refcnt) {                                             \
 741                 ret = -EBUSY;                                           \
 742                 goto end;                                               \
 743         }                                                               \
 744                                                                         \
 745         ret = kstrtou##prec(page, 0, &num);                             \
 746         if (ret)                                                        \
 747                 goto end;                                               \
 748                                                                         \
 749         if (num > limit) {                                              \
 750                 ret = -EINVAL;                                          \
 751                 goto end;                                               \
 752         }                                                               \
 753         opts->name = num;                                               \
 754         ret = len;                                                      \
 755                                                                         \
 756 end:                                                                    \
 757         mutex_unlock(&opts->lock);                                      \
 758         return ret;                                                     \
 759 }                                                                       \
 760                                                                         \
 761 CONFIGFS_ATTR(f_hid_opts_, name)
 762
 763 F_HID_OPT(subclass, 8, 255);
 764 F_HID_OPT(protocol, 8, 255);
 765 F_HID_OPT(report_length, 16, 65535);
 766
 767 static ssize_t f_hid_opts_report_desc_show(struct config_item *item, char *page)
 768 {
 769         struct f_hid_opts *opts = to_f_hid_opts(item);
 770         int result;
 771
 772         mutex_lock(&opts->lock);
 773         result = opts->report_desc_length;
 774         memcpy(page, opts->report_desc, opts->report_desc_length);
 775         mutex_unlock(&opts->lock);
 776
 777         return result;
 778 }
 779
 780 static ssize_t f_hid_opts_report_desc_store(struct config_item *item,
 781                                             const char *page, size_t len)
 782 {
 783         struct f_hid_opts *opts = to_f_hid_opts(item);
 784         int ret = -EBUSY;
 785         char *d;
 786
 787         mutex_lock(&opts->lock);
 788
 789         if (opts->refcnt)
 790                 goto end;
 791         if (len > PAGE_SIZE) {
 792                 ret = -ENOSPC;
 793                 goto end;
 794         }
 795         d = kmemdup(page, len, GFP_KERNEL);
 796         if (!d) {
 797                 ret = -ENOMEM;
 798                 goto end;
 799         }
 800         kfree(opts->report_desc);
 801         opts->report_desc = d;
 802         opts->report_desc_length = len;
 803         opts->report_desc_alloc = true;
 804         ret = len;
 805 end:
 806         mutex_unlock(&opts->lock);
 807         return ret;
 808 }
 809
 810 CONFIGFS_ATTR(f_hid_opts_, report_desc);
 811
 812 static struct configfs_attribute *hid_attrs[] = {
 813         &f_hid_opts_attr_subclass,
 814         &f_hid_opts_attr_protocol,
 815         &f_hid_opts_attr_report_length,
 816         &f_hid_opts_attr_report_desc,
 817         NULL,
 818 };
 819
 820 static struct config_item_type hid_func_type = {
 821         .ct_item_ops    = &hidg_item_ops,
 822         .ct_attrs       = hid_attrs,
 823         .ct_owner       = THIS_MODULE,
 824 };
 825
 826 static inline void hidg_put_minor(int minor)
 827 {
 828         ida_simple_remove(&hidg_ida, minor);
 829 }
 830
 831 static void hidg_free_inst(struct usb_function_instance *f)
 832 {
 833         struct f_hid_opts *opts;
 834
 835         opts = container_of(f, struct f_hid_opts, func_inst);
 836
 837         mutex_lock(&hidg_ida_lock);
 838
 839         hidg_put_minor(opts->minor);
 840         if (idr_is_empty(&hidg_ida.idr))
 841                 ghid_cleanup();
 842
 843         mutex_unlock(&hidg_ida_lock);
 844
 845         if (opts->report_desc_alloc)
 846                 kfree(opts->report_desc);
 847
 848         kfree(opts);
 849 }
 850
 851 static struct usb_function_instance *hidg_alloc_inst(void)
 852 {
 853         struct f_hid_opts *opts;
 854         struct usb_function_instance *ret;
 855         int status = 0;
 856
 857         opts = kzalloc(sizeof(*opts), GFP_KERNEL);
 858         if (!opts)
 859                 return ERR_PTR(-ENOMEM);
 860         mutex_init(&opts->lock);
 861         opts->func_inst.free_func_inst = hidg_free_inst;
 862         ret = &opts->func_inst;
 863
 864         mutex_lock(&hidg_ida_lock);
 865
 866         if (idr_is_empty(&hidg_ida.idr)) {
 867                 status = ghid_setup(NULL, HIDG_MINORS);
 868                 if (status)  {
 869                         ret = ERR_PTR(status);
 870                         kfree(opts);
 871                         goto unlock;
 872                 }
 873         }
 874
 875         opts->minor = hidg_get_minor();
 876         if (opts->minor < 0) {
 877                 ret = ERR_PTR(opts->minor);
 878                 kfree(opts);
 879                 if (idr_is_empty(&hidg_ida.idr))
 880                         ghid_cleanup();
 881                 goto unlock;
 882         }
 883         config_group_init_type_name(&opts->func_inst.group, "", &hid_func_type);
 884
 885 unlock:
 886         mutex_unlock(&hidg_ida_lock);
 887         return ret;
 888 }
 889
 890 static void hidg_free(struct usb_function *f)
 891 {
 892         struct f_hidg *hidg;
 893         struct f_hid_opts *opts;
 894
 895         hidg = func_to_hidg(f);
 896         opts = container_of(f->fi, struct f_hid_opts, func_inst);
 897         kfree(hidg->report_desc);
 898         kfree(hidg);
 899         mutex_lock(&opts->lock);
 900         --opts->refcnt;
 901         mutex_unlock(&opts->lock);
 902 }
 903
 904 static void hidg_unbind(struct usb_configuration *c, struct usb_function *f)
 905 {
 906         struct f_hidg *hidg = func_to_hidg(f);
 907
 908         device_destroy(hidg_class, MKDEV(major, hidg->minor));
 909         cdev_del(&hidg->cdev);
 910
 911         /* disable/free request and end point */
 912         usb_ep_disable(hidg->in_ep);
 913         kfree(hidg->req->buf);
 914         usb_ep_free_request(hidg->in_ep, hidg->req);
 915
 916         usb_free_all_descriptors(f);
 917 }
 918
 919 static struct usb_function *hidg_alloc(struct usb_function_instance *fi)
 920 {
 921         struct f_hidg *hidg;
 922         struct f_hid_opts *opts;
 923
 924         /* allocate and initialize one new instance */
 925         hidg = kzalloc(sizeof(*hidg), GFP_KERNEL);
 926         if (!hidg)
 927                 return ERR_PTR(-ENOMEM);
 928
 929         opts = container_of(fi, struct f_hid_opts, func_inst);
 930
 931         mutex_lock(&opts->lock);
 932         ++opts->refcnt;
 933
 934         hidg->minor = opts->minor;
 935         hidg->bInterfaceSubClass = opts->subclass;
 936         hidg->bInterfaceProtocol = opts->protocol;
 937         hidg->report_length = opts->report_length;
 938         hidg->report_desc_length = opts->report_desc_length;
 939         if (opts->report_desc) {
 940                 hidg->report_desc = kmemdup(opts->report_desc,
 941                                             opts->report_desc_length,
 942                                             GFP_KERNEL);
 943                 if (!hidg->report_desc) {
 944                         kfree(hidg);
 945                         mutex_unlock(&opts->lock);
 946                         return ERR_PTR(-ENOMEM);
 947                 }
 948         }
 949
 950         mutex_unlock(&opts->lock);
 951
 952         hidg->func.name    = "hid";
 953         hidg->func.bind    = hidg_bind;
 954         hidg->func.unbind  = hidg_unbind;
 955         hidg->func.set_alt = hidg_set_alt;
 956         hidg->func.disable = hidg_disable;
 957         hidg->func.setup   = hidg_setup;
 958         hidg->func.free_func = hidg_free;
 959
 960         /* this could me made configurable at some point */
 961         hidg->qlen         = 4;
 962
 963         return &hidg->func;
 964 }
 965
 966 DECLARE_USB_FUNCTION_INIT(hid, hidg_alloc_inst, hidg_alloc);
 967 MODULE_LICENSE("GPL");
 968 MODULE_AUTHOR("Fabien Chouteau");
 969
 970 int ghid_setup(struct usb_gadget *g, int count)
 971 {
 972         int status;
 973         dev_t dev;
 974
 975         hidg_class = class_create(THIS_MODULE, "hidg");
 976         if (IS_ERR(hidg_class)) {
 977                 status = PTR_ERR(hidg_class);
 978                 hidg_class = NULL;
 979                 return status;
 980         }
 981
 982         status = alloc_chrdev_region(&dev, 0, count, "hidg");
 983         if (status) {
 984                 class_destroy(hidg_class);
 985                 hidg_class = NULL;
 986                 return status;
 987         }
 988
 989         major = MAJOR(dev);
 990         minors = count;
 991
 992         return 0;
 993 }
 994
 995 void ghid_cleanup(void)
 996 {
 997         if (major) {
 998                 unregister_chrdev_region(MKDEV(major, 0), minors);
 999                 major = minors = 0;
1000         }
1001
1002         class_destroy(hidg_class);
1003         hidg_class = NULL;
1004 }