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