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