drivers/usb/gadget/udc/udc-core.c

   1 /**
   2  * udc.c - Core UDC Framework
   3  *
   4  * Copyright (C) 2010 Texas Instruments
   5  * Author: Felipe Balbi <balbi@ti.com>
   6  *
   7  * This program is free software: you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License version 2  of
   9  * the License as published by the Free Software Foundation.
  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  * You should have received a copy of the GNU General Public License
  17  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  18  */
  19
  20 #include <linux/kernel.h>
  21 #include <linux/module.h>
  22 #include <linux/device.h>
  23 #include <linux/list.h>
  24 #include <linux/err.h>
  25 #include <linux/dma-mapping.h>
  26 #include <linux/workqueue.h>
  27
  28 #include <linux/usb/ch9.h>
  29 #include <linux/usb/gadget.h>
  30 #include <linux/usb.h>
  31
  32 /**
  33  * struct usb_udc - describes one usb device controller
  34  * @driver - the gadget driver pointer. For use by the class code
  35  * @dev - the child device to the actual controller
  36  * @gadget - the gadget. For use by the class code
  37  * @list - for use by the udc class driver
  38  * @vbus - for udcs who care about vbus status, this value is real vbus status;
  39  * for udcs who do not care about vbus status, this value is always true
  40  *
  41  * This represents the internal data structure which is used by the UDC-class
  42  * to hold information about udc driver and gadget together.
  43  */
  44 struct usb_udc {
  45         struct usb_gadget_driver        *driver;
  46         struct usb_gadget               *gadget;
  47         struct device                   dev;
  48         struct list_head                list;
  49         bool                            vbus;
  50 };
  51
  52 static struct class *udc_class;
  53 static LIST_HEAD(udc_list);
  54 static DEFINE_MUTEX(udc_lock);
  55
  56 /* ------------------------------------------------------------------------- */
  57
  58 #ifdef  CONFIG_HAS_DMA
  59
  60 int usb_gadget_map_request(struct usb_gadget *gadget,
  61                 struct usb_request *req, int is_in)
  62 {
  63         if (req->length == 0)
  64                 return 0;
  65
  66         if (req->num_sgs) {
  67                 int     mapped;
  68
  69                 mapped = dma_map_sg(&gadget->dev, req->sg, req->num_sgs,
  70                                 is_in ? DMA_TO_DEVICE : DMA_FROM_DEVICE);
  71                 if (mapped == 0) {
  72                         dev_err(&gadget->dev, "failed to map SGs\n");
  73                         return -EFAULT;
  74                 }
  75
  76                 req->num_mapped_sgs = mapped;
  77         } else {
  78                 req->dma = dma_map_single(&gadget->dev, req->buf, req->length,
  79                                 is_in ? DMA_TO_DEVICE : DMA_FROM_DEVICE);
  80
  81                 if (dma_mapping_error(&gadget->dev, req->dma)) {
  82                         dev_err(&gadget->dev, "failed to map buffer\n");
  83                         return -EFAULT;
  84                 }
  85         }
  86
  87         return 0;
  88 }
  89 EXPORT_SYMBOL_GPL(usb_gadget_map_request);
  90
  91 void usb_gadget_unmap_request(struct usb_gadget *gadget,
  92                 struct usb_request *req, int is_in)
  93 {
  94         if (req->length == 0)
  95                 return;
  96
  97         if (req->num_mapped_sgs) {
  98                 dma_unmap_sg(&gadget->dev, req->sg, req->num_mapped_sgs,
  99                                 is_in ? DMA_TO_DEVICE : DMA_FROM_DEVICE);
 100
 101                 req->num_mapped_sgs = 0;
 102         } else {
 103                 dma_unmap_single(&gadget->dev, req->dma, req->length,
 104                                 is_in ? DMA_TO_DEVICE : DMA_FROM_DEVICE);
 105         }
 106 }
 107 EXPORT_SYMBOL_GPL(usb_gadget_unmap_request);
 108
 109 #endif  /* CONFIG_HAS_DMA */
 110
 111 /* ------------------------------------------------------------------------- */
 112
 113 /**
 114  * usb_gadget_giveback_request - give the request back to the gadget layer
 115  * Context: in_interrupt()
 116  *
 117  * This is called by device controller drivers in order to return the
 118  * completed request back to the gadget layer.
 119  */
 120 void usb_gadget_giveback_request(struct usb_ep *ep,
 121                 struct usb_request *req)
 122 {
 123         if (likely(req->status == 0))
 124                 usb_led_activity(USB_LED_EVENT_GADGET);
 125
 126         req->complete(ep, req);
 127 }
 128 EXPORT_SYMBOL_GPL(usb_gadget_giveback_request);
 129
 130 /* ------------------------------------------------------------------------- */
 131
 132 static void usb_gadget_state_work(struct work_struct *work)
 133 {
 134         struct usb_gadget *gadget = work_to_gadget(work);
 135         struct usb_udc *udc = gadget->udc;
 136
 137         if (udc)
 138                 sysfs_notify(&udc->dev.kobj, NULL, "state");
 139 }
 140
 141 void usb_gadget_set_state(struct usb_gadget *gadget,
 142                 enum usb_device_state state)
 143 {
 144         gadget->state = state;
 145         schedule_work(&gadget->work);
 146 }
 147 EXPORT_SYMBOL_GPL(usb_gadget_set_state);
 148
 149 /* ------------------------------------------------------------------------- */
 150
 151 static void usb_udc_connect_control(struct usb_udc *udc)
 152 {
 153         if (udc->vbus)
 154                 usb_gadget_connect(udc->gadget);
 155         else
 156                 usb_gadget_disconnect(udc->gadget);
 157 }
 158
 159 /**
 160  * usb_udc_vbus_handler - updates the udc core vbus status, and try to
 161  * connect or disconnect gadget
 162  * @gadget: The gadget which vbus change occurs
 163  * @status: The vbus status
 164  *
 165  * The udc driver calls it when it wants to connect or disconnect gadget
 166  * according to vbus status.
 167  */
 168 void usb_udc_vbus_handler(struct usb_gadget *gadget, bool status)
 169 {
 170         struct usb_udc *udc = gadget->udc;
 171
 172         if (udc) {
 173                 udc->vbus = status;
 174                 usb_udc_connect_control(udc);
 175         }
 176 }
 177 EXPORT_SYMBOL_GPL(usb_udc_vbus_handler);
 178
 179 /**
 180  * usb_gadget_udc_reset - notifies the udc core that bus reset occurs
 181  * @gadget: The gadget which bus reset occurs
 182  * @driver: The gadget driver we want to notify
 183  *
 184  * If the udc driver has bus reset handler, it needs to call this when the bus
 185  * reset occurs, it notifies the gadget driver that the bus reset occurs as
 186  * well as updates gadget state.
 187  */
 188 void usb_gadget_udc_reset(struct usb_gadget *gadget,
 189                 struct usb_gadget_driver *driver)
 190 {
 191         driver->reset(gadget);
 192         usb_gadget_set_state(gadget, USB_STATE_DEFAULT);
 193 }
 194 EXPORT_SYMBOL_GPL(usb_gadget_udc_reset);
 195
 196 /**
 197  * usb_gadget_udc_start - tells usb device controller to start up
 198  * @udc: The UDC to be started
 199  *
 200  * This call is issued by the UDC Class driver when it's about
 201  * to register a gadget driver to the device controller, before
 202  * calling gadget driver's bind() method.
 203  *
 204  * It allows the controller to be powered off until strictly
 205  * necessary to have it powered on.
 206  *
 207  * Returns zero on success, else negative errno.
 208  */
 209 static inline int usb_gadget_udc_start(struct usb_udc *udc)
 210 {
 211         return udc->gadget->ops->udc_start(udc->gadget, udc->driver);
 212 }
 213
 214 /**
 215  * usb_gadget_udc_stop - tells usb device controller we don't need it anymore
 216  * @gadget: The device we want to stop activity
 217  * @driver: The driver to unbind from @gadget
 218  *
 219  * This call is issued by the UDC Class driver after calling
 220  * gadget driver's unbind() method.
 221  *
 222  * The details are implementation specific, but it can go as
 223  * far as powering off UDC completely and disable its data
 224  * line pullups.
 225  */
 226 static inline void usb_gadget_udc_stop(struct usb_udc *udc)
 227 {
 228         udc->gadget->ops->udc_stop(udc->gadget);
 229 }
 230
 231 /**
 232  * usb_udc_release - release the usb_udc struct
 233  * @dev: the dev member within usb_udc
 234  *
 235  * This is called by driver's core in order to free memory once the last
 236  * reference is released.
 237  */
 238 static void usb_udc_release(struct device *dev)
 239 {
 240         struct usb_udc *udc;
 241
 242         udc = container_of(dev, struct usb_udc, dev);
 243         dev_dbg(dev, "releasing '%s'\n", dev_name(dev));
 244         kfree(udc);
 245 }
 246
 247 static const struct attribute_group *usb_udc_attr_groups[];
 248
 249 static void usb_udc_nop_release(struct device *dev)
 250 {
 251         dev_vdbg(dev, "%s\n", __func__);
 252 }
 253
 254 /**
 255  * usb_add_gadget_udc_release - adds a new gadget to the udc class driver list
 256  * @parent: the parent device to this udc. Usually the controller driver's
 257  * device.
 258  * @gadget: the gadget to be added to the list.
 259  * @release: a gadget release function.
 260  *
 261  * Returns zero on success, negative errno otherwise.
 262  */
 263 int usb_add_gadget_udc_release(struct device *parent, struct usb_gadget *gadget,
 264                 void (*release)(struct device *dev))
 265 {
 266         struct usb_udc          *udc;
 267         int                     ret = -ENOMEM;
 268
 269         udc = kzalloc(sizeof(*udc), GFP_KERNEL);
 270         if (!udc)
 271                 goto err1;
 272
 273         dev_set_name(&gadget->dev, "gadget");
 274         INIT_WORK(&gadget->work, usb_gadget_state_work);
 275         gadget->dev.parent = parent;
 276
 277 #ifdef  CONFIG_HAS_DMA
 278         dma_set_coherent_mask(&gadget->dev, parent->coherent_dma_mask);
 279         gadget->dev.dma_parms = parent->dma_parms;
 280         gadget->dev.dma_mask = parent->dma_mask;
 281 #endif
 282
 283         if (release)
 284                 gadget->dev.release = release;
 285         else
 286                 gadget->dev.release = usb_udc_nop_release;
 287
 288         ret = device_register(&gadget->dev);
 289         if (ret)
 290                 goto err2;
 291
 292         device_initialize(&udc->dev);
 293         udc->dev.release = usb_udc_release;
 294         udc->dev.class = udc_class;
 295         udc->dev.groups = usb_udc_attr_groups;
 296         udc->dev.parent = parent;
 297         ret = dev_set_name(&udc->dev, "%s", kobject_name(&parent->kobj));
 298         if (ret)
 299                 goto err3;
 300
 301         udc->gadget = gadget;
 302         gadget->udc = udc;
 303
 304         mutex_lock(&udc_lock);
 305         list_add_tail(&udc->list, &udc_list);
 306
 307         ret = device_add(&udc->dev);
 308         if (ret)
 309                 goto err4;
 310
 311         usb_gadget_set_state(gadget, USB_STATE_NOTATTACHED);
 312         udc->vbus = true;
 313
 314         mutex_unlock(&udc_lock);
 315
 316         return 0;
 317
 318 err4:
 319         list_del(&udc->list);
 320         mutex_unlock(&udc_lock);
 321
 322 err3:
 323         put_device(&udc->dev);
 324
 325 err2:
 326         put_device(&gadget->dev);
 327         kfree(udc);
 328
 329 err1:
 330         return ret;
 331 }
 332 EXPORT_SYMBOL_GPL(usb_add_gadget_udc_release);
 333
 334 /**
 335  * usb_add_gadget_udc - adds a new gadget to the udc class driver list
 336  * @parent: the parent device to this udc. Usually the controller
 337  * driver's device.
 338  * @gadget: the gadget to be added to the list
 339  *
 340  * Returns zero on success, negative errno otherwise.
 341  */
 342 int usb_add_gadget_udc(struct device *parent, struct usb_gadget *gadget)
 343 {
 344         return usb_add_gadget_udc_release(parent, gadget, NULL);
 345 }
 346 EXPORT_SYMBOL_GPL(usb_add_gadget_udc);
 347
 348 static void usb_gadget_remove_driver(struct usb_udc *udc)
 349 {
 350         dev_dbg(&udc->dev, "unregistering UDC driver [%s]\n",
 351                         udc->driver->function);
 352
 353         kobject_uevent(&udc->dev.kobj, KOBJ_CHANGE);
 354
 355         usb_gadget_disconnect(udc->gadget);
 356         udc->driver->disconnect(udc->gadget);
 357         udc->driver->unbind(udc->gadget);
 358         usb_gadget_udc_stop(udc);
 359
 360         udc->driver = NULL;
 361         udc->dev.driver = NULL;
 362         udc->gadget->dev.driver = NULL;
 363 }
 364
 365 /**
 366  * usb_del_gadget_udc - deletes @udc from udc_list
 367  * @gadget: the gadget to be removed.
 368  *
 369  * This, will call usb_gadget_unregister_driver() if
 370  * the @udc is still busy.
 371  */
 372 void usb_del_gadget_udc(struct usb_gadget *gadget)
 373 {
 374         struct usb_udc *udc = gadget->udc;
 375
 376         if (!udc)
 377                 return;
 378
 379         dev_vdbg(gadget->dev.parent, "unregistering gadget\n");
 380
 381         mutex_lock(&udc_lock);
 382         list_del(&udc->list);
 383         mutex_unlock(&udc_lock);
 384
 385         if (udc->driver)
 386                 usb_gadget_remove_driver(udc);
 387
 388         kobject_uevent(&udc->dev.kobj, KOBJ_REMOVE);
 389         flush_work(&gadget->work);
 390         device_unregister(&udc->dev);
 391         device_unregister(&gadget->dev);
 392 }
 393 EXPORT_SYMBOL_GPL(usb_del_gadget_udc);
 394
 395 /* ------------------------------------------------------------------------- */
 396
 397 static int udc_bind_to_driver(struct usb_udc *udc, struct usb_gadget_driver *driver)
 398 {
 399         int ret;
 400
 401         dev_dbg(&udc->dev, "registering UDC driver [%s]\n",
 402                         driver->function);
 403
 404         udc->driver = driver;
 405         udc->dev.driver = &driver->driver;
 406         udc->gadget->dev.driver = &driver->driver;
 407
 408         ret = driver->bind(udc->gadget, driver);
 409         if (ret)
 410                 goto err1;
 411         ret = usb_gadget_udc_start(udc);
 412         if (ret) {
 413                 driver->unbind(udc->gadget);
 414                 goto err1;
 415         }
 416         usb_udc_connect_control(udc);
 417
 418         kobject_uevent(&udc->dev.kobj, KOBJ_CHANGE);
 419         return 0;
 420 err1:
 421         if (ret != -EISNAM)
 422                 dev_err(&udc->dev, "failed to start %s: %d\n",
 423                         udc->driver->function, ret);
 424         udc->driver = NULL;
 425         udc->dev.driver = NULL;
 426         udc->gadget->dev.driver = NULL;
 427         return ret;
 428 }
 429
 430 int usb_udc_attach_driver(const char *name, struct usb_gadget_driver *driver)
 431 {
 432         struct usb_udc *udc = NULL;
 433         int ret = -ENODEV;
 434
 435         mutex_lock(&udc_lock);
 436         list_for_each_entry(udc, &udc_list, list) {
 437                 ret = strcmp(name, dev_name(&udc->dev));
 438                 if (!ret)
 439                         break;
 440         }
 441         if (ret) {
 442                 ret = -ENODEV;
 443                 goto out;
 444         }
 445         if (udc->driver) {
 446                 ret = -EBUSY;
 447                 goto out;
 448         }
 449         ret = udc_bind_to_driver(udc, driver);
 450 out:
 451         mutex_unlock(&udc_lock);
 452         return ret;
 453 }
 454 EXPORT_SYMBOL_GPL(usb_udc_attach_driver);
 455
 456 int usb_gadget_probe_driver(struct usb_gadget_driver *driver)
 457 {
 458         struct usb_udc          *udc = NULL;
 459         int                     ret;
 460
 461         if (!driver || !driver->bind || !driver->setup)
 462                 return -EINVAL;
 463
 464         mutex_lock(&udc_lock);
 465         list_for_each_entry(udc, &udc_list, list) {
 466                 /* For now we take the first one */
 467                 if (!udc->driver)
 468                         goto found;
 469         }
 470
 471         pr_debug("couldn't find an available UDC\n");
 472         mutex_unlock(&udc_lock);
 473         return -ENODEV;
 474 found:
 475         ret = udc_bind_to_driver(udc, driver);
 476         mutex_unlock(&udc_lock);
 477         return ret;
 478 }
 479 EXPORT_SYMBOL_GPL(usb_gadget_probe_driver);
 480
 481 int usb_gadget_unregister_driver(struct usb_gadget_driver *driver)
 482 {
 483         struct usb_udc          *udc = NULL;
 484         int                     ret = -ENODEV;
 485
 486         if (!driver || !driver->unbind)
 487                 return -EINVAL;
 488
 489         mutex_lock(&udc_lock);
 490         list_for_each_entry(udc, &udc_list, list)
 491                 if (udc->driver == driver) {
 492                         usb_gadget_remove_driver(udc);
 493                         usb_gadget_set_state(udc->gadget,
 494                                         USB_STATE_NOTATTACHED);
 495                         ret = 0;
 496                         break;
 497                 }
 498
 499         mutex_unlock(&udc_lock);
 500         return ret;
 501 }
 502 EXPORT_SYMBOL_GPL(usb_gadget_unregister_driver);
 503
 504 /* ------------------------------------------------------------------------- */
 505
 506 static ssize_t usb_udc_srp_store(struct device *dev,
 507                 struct device_attribute *attr, const char *buf, size_t n)
 508 {
 509         struct usb_udc          *udc = container_of(dev, struct usb_udc, dev);
 510
 511         if (sysfs_streq(buf, "1"))
 512                 usb_gadget_wakeup(udc->gadget);
 513
 514         return n;
 515 }
 516 static DEVICE_ATTR(srp, S_IWUSR, NULL, usb_udc_srp_store);
 517
 518 static ssize_t usb_udc_softconn_store(struct device *dev,
 519                 struct device_attribute *attr, const char *buf, size_t n)
 520 {
 521         struct usb_udc          *udc = container_of(dev, struct usb_udc, dev);
 522
 523         if (!udc->driver) {
 524                 dev_err(dev, "soft-connect without a gadget driver\n");
 525                 return -EOPNOTSUPP;
 526         }
 527
 528         if (sysfs_streq(buf, "connect")) {
 529                 usb_gadget_udc_start(udc);
 530                 usb_gadget_connect(udc->gadget);
 531         } else if (sysfs_streq(buf, "disconnect")) {
 532                 usb_gadget_disconnect(udc->gadget);
 533                 udc->driver->disconnect(udc->gadget);
 534                 usb_gadget_udc_stop(udc);
 535         } else {
 536                 dev_err(dev, "unsupported command '%s'\n", buf);
 537                 return -EINVAL;
 538         }
 539
 540         return n;
 541 }
 542 static DEVICE_ATTR(soft_connect, S_IWUSR, NULL, usb_udc_softconn_store);
 543
 544 static ssize_t state_show(struct device *dev, struct device_attribute *attr,
 545                           char *buf)
 546 {
 547         struct usb_udc          *udc = container_of(dev, struct usb_udc, dev);
 548         struct usb_gadget       *gadget = udc->gadget;
 549
 550         return sprintf(buf, "%s\n", usb_state_string(gadget->state));
 551 }
 552 static DEVICE_ATTR_RO(state);
 553
 554 #define USB_UDC_SPEED_ATTR(name, param)                                 \
 555 ssize_t name##_show(struct device *dev,                                 \
 556                 struct device_attribute *attr, char *buf)               \
 557 {                                                                       \
 558         struct usb_udc *udc = container_of(dev, struct usb_udc, dev);   \
 559         return snprintf(buf, PAGE_SIZE, "%s\n",                         \
 560                         usb_speed_string(udc->gadget->param));          \
 561 }                                                                       \
 562 static DEVICE_ATTR_RO(name)
 563
 564 static USB_UDC_SPEED_ATTR(current_speed, speed);
 565 static USB_UDC_SPEED_ATTR(maximum_speed, max_speed);
 566
 567 #define USB_UDC_ATTR(name)                                      \
 568 ssize_t name##_show(struct device *dev,                         \
 569                 struct device_attribute *attr, char *buf)       \
 570 {                                                               \
 571         struct usb_udc          *udc = container_of(dev, struct usb_udc, dev); \
 572         struct usb_gadget       *gadget = udc->gadget;          \
 573                                                                 \
 574         return snprintf(buf, PAGE_SIZE, "%d\n", gadget->name);  \
 575 }                                                               \
 576 static DEVICE_ATTR_RO(name)
 577
 578 static USB_UDC_ATTR(is_otg);
 579 static USB_UDC_ATTR(is_a_peripheral);
 580 static USB_UDC_ATTR(b_hnp_enable);
 581 static USB_UDC_ATTR(a_hnp_support);
 582 static USB_UDC_ATTR(a_alt_hnp_support);
 583 static USB_UDC_ATTR(is_selfpowered);
 584
 585 static struct attribute *usb_udc_attrs[] = {
 586         &dev_attr_srp.attr,
 587         &dev_attr_soft_connect.attr,
 588         &dev_attr_state.attr,
 589         &dev_attr_current_speed.attr,
 590         &dev_attr_maximum_speed.attr,
 591
 592         &dev_attr_is_otg.attr,
 593         &dev_attr_is_a_peripheral.attr,
 594         &dev_attr_b_hnp_enable.attr,
 595         &dev_attr_a_hnp_support.attr,
 596         &dev_attr_a_alt_hnp_support.attr,
 597         &dev_attr_is_selfpowered.attr,
 598         NULL,
 599 };
 600
 601 static const struct attribute_group usb_udc_attr_group = {
 602         .attrs = usb_udc_attrs,
 603 };
 604
 605 static const struct attribute_group *usb_udc_attr_groups[] = {
 606         &usb_udc_attr_group,
 607         NULL,
 608 };
 609
 610 static int usb_udc_uevent(struct device *dev, struct kobj_uevent_env *env)
 611 {
 612         struct usb_udc          *udc = container_of(dev, struct usb_udc, dev);
 613         int                     ret;
 614
 615         ret = add_uevent_var(env, "USB_UDC_NAME=%s", udc->gadget->name);
 616         if (ret) {
 617                 dev_err(dev, "failed to add uevent USB_UDC_NAME\n");
 618                 return ret;
 619         }
 620
 621         if (udc->driver) {
 622                 ret = add_uevent_var(env, "USB_UDC_DRIVER=%s",
 623                                 udc->driver->function);
 624                 if (ret) {
 625                         dev_err(dev, "failed to add uevent USB_UDC_DRIVER\n");
 626                         return ret;
 627                 }
 628         }
 629
 630         return 0;
 631 }
 632
 633 static int __init usb_udc_init(void)
 634 {
 635         udc_class = class_create(THIS_MODULE, "udc");
 636         if (IS_ERR(udc_class)) {
 637                 pr_err("failed to create udc class --> %ld\n",
 638                                 PTR_ERR(udc_class));
 639                 return PTR_ERR(udc_class);
 640         }
 641
 642         udc_class->dev_uevent = usb_udc_uevent;
 643         return 0;
 644 }
 645 subsys_initcall(usb_udc_init);
 646
 647 static void __exit usb_udc_exit(void)
 648 {
 649         class_destroy(udc_class);
 650 }
 651 module_exit(usb_udc_exit);
 652
 653 MODULE_DESCRIPTION("UDC Framework");
 654 MODULE_AUTHOR("Felipe Balbi <balbi@ti.com>");
 655 MODULE_LICENSE("GPL v2");