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
  26 #include <linux/usb/ch9.h>
  27 #include <linux/usb/gadget.h>
  28
  29 /**
  30  * struct usb_udc - describes one usb device controller
  31  * @driver - the gadget driver pointer. For use by the class code
  32  * @dev - the child device to the actual controller
  33  * @gadget - the gadget. For use by the class code
  34  * @list - for use by the udc class driver
  35  *
  36  * This represents the internal data structure which is used by the UDC-class
  37  * to hold information about udc driver and gadget together.
  38  */
  39 struct usb_udc {
  40         struct usb_gadget_driver        *driver;
  41         struct usb_gadget               *gadget;
  42         struct device                   dev;
  43         struct list_head                list;
  44 };
  45
  46 static struct class *udc_class;
  47 static LIST_HEAD(udc_list);
  48 static DEFINE_MUTEX(udc_lock);
  49
  50 /* ------------------------------------------------------------------------- */
  51
  52 /**
  53  * usb_gadget_start - tells usb device controller to start up
  54  * @gadget: The gadget we want to get started
  55  * @driver: The driver we want to bind to @gadget
  56  * @bind: The bind function for @driver
  57  *
  58  * This call is issued by the UDC Class driver when it's about
  59  * to register a gadget driver to the device controller, before
  60  * calling gadget driver's bind() method.
  61  *
  62  * It allows the controller to be powered off until strictly
  63  * necessary to have it powered on.
  64  *
  65  * Returns zero on success, else negative errno.
  66  */
  67 static inline int usb_gadget_start(struct usb_gadget *gadget,
  68                 struct usb_gadget_driver *driver,
  69                 int (*bind)(struct usb_gadget *))
  70 {
  71         return gadget->ops->start(driver, bind);
  72 }
  73
  74 /**
  75  * usb_gadget_udc_start - tells usb device controller to start up
  76  * @gadget: The gadget we want to get started
  77  * @driver: The driver we want to bind to @gadget
  78  *
  79  * This call is issued by the UDC Class driver when it's about
  80  * to register a gadget driver to the device controller, before
  81  * calling gadget driver's bind() method.
  82  *
  83  * It allows the controller to be powered off until strictly
  84  * necessary to have it powered on.
  85  *
  86  * Returns zero on success, else negative errno.
  87  */
  88 static inline int usb_gadget_udc_start(struct usb_gadget *gadget,
  89                 struct usb_gadget_driver *driver)
  90 {
  91         return gadget->ops->udc_start(gadget, driver);
  92 }
  93
  94 /**
  95  * usb_gadget_stop - tells usb device controller we don't need it anymore
  96  * @gadget: The device we want to stop activity
  97  * @driver: The driver to unbind from @gadget
  98  *
  99  * This call is issued by the UDC Class driver after calling
 100  * gadget driver's unbind() method.
 101  *
 102  * The details are implementation specific, but it can go as
 103  * far as powering off UDC completely and disable its data
 104  * line pullups.
 105  */
 106 static inline void usb_gadget_stop(struct usb_gadget *gadget,
 107                 struct usb_gadget_driver *driver)
 108 {
 109         gadget->ops->stop(driver);
 110 }
 111
 112 /**
 113  * usb_gadget_udc_stop - tells usb device controller we don't need it anymore
 114  * @gadget: The device we want to stop activity
 115  * @driver: The driver to unbind from @gadget
 116  *
 117  * This call is issued by the UDC Class driver after calling
 118  * gadget driver's unbind() method.
 119  *
 120  * The details are implementation specific, but it can go as
 121  * far as powering off UDC completely and disable its data
 122  * line pullups.
 123  */
 124 static inline void usb_gadget_udc_stop(struct usb_gadget *gadget,
 125                 struct usb_gadget_driver *driver)
 126 {
 127         gadget->ops->udc_stop(gadget, driver);
 128 }
 129
 130 /**
 131  * usb_udc_release - release the usb_udc struct
 132  * @dev: the dev member within usb_udc
 133  *
 134  * This is called by driver's core in order to free memory once the last
 135  * reference is released.
 136  */
 137 static void usb_udc_release(struct device *dev)
 138 {
 139         struct usb_udc *udc;
 140
 141         udc = container_of(dev, struct usb_udc, dev);
 142         dev_dbg(dev, "releasing '%s'\n", dev_name(dev));
 143         kfree(udc);
 144 }
 145
 146 static const struct attribute_group *usb_udc_attr_groups[];
 147 /**
 148  * usb_add_gadget_udc - adds a new gadget to the udc class driver list
 149  * @parent: the parent device to this udc. Usually the controller
 150  * driver's device.
 151  * @gadget: the gadget to be added to the list
 152  *
 153  * Returns zero on success, negative errno otherwise.
 154  */
 155 int usb_add_gadget_udc(struct device *parent, struct usb_gadget *gadget)
 156 {
 157         struct usb_udc          *udc;
 158         int                     ret = -ENOMEM;
 159
 160         udc = kzalloc(sizeof(*udc), GFP_KERNEL);
 161         if (!udc)
 162                 goto err1;
 163
 164         device_initialize(&udc->dev);
 165         udc->dev.release = usb_udc_release;
 166         udc->dev.class = udc_class;
 167         udc->dev.groups = usb_udc_attr_groups;
 168         udc->dev.parent = parent;
 169         ret = dev_set_name(&udc->dev, "%s", kobject_name(&parent->kobj));
 170         if (ret)
 171                 goto err2;
 172
 173         udc->gadget = gadget;
 174
 175         mutex_lock(&udc_lock);
 176         list_add_tail(&udc->list, &udc_list);
 177
 178         ret = device_add(&udc->dev);
 179         if (ret)
 180                 goto err3;
 181
 182         mutex_unlock(&udc_lock);
 183
 184         return 0;
 185 err3:
 186         list_del(&udc->list);
 187         mutex_unlock(&udc_lock);
 188
 189 err2:
 190         put_device(&udc->dev);
 191
 192 err1:
 193         return ret;
 194 }
 195 EXPORT_SYMBOL_GPL(usb_add_gadget_udc);
 196
 197 static int udc_is_newstyle(struct usb_udc *udc)
 198 {
 199         if (udc->gadget->ops->udc_start && udc->gadget->ops->udc_stop)
 200                 return 1;
 201         return 0;
 202 }
 203
 204
 205 static void usb_gadget_remove_driver(struct usb_udc *udc)
 206 {
 207         dev_dbg(&udc->dev, "unregistering UDC driver [%s]\n",
 208                         udc->gadget->name);
 209
 210         kobject_uevent(&udc->dev.kobj, KOBJ_CHANGE);
 211
 212         if (udc_is_newstyle(udc)) {
 213                 udc->driver->disconnect(udc->gadget);
 214                 udc->driver->unbind(udc->gadget);
 215                 usb_gadget_udc_stop(udc->gadget, udc->driver);
 216                 usb_gadget_disconnect(udc->gadget);
 217         } else {
 218                 usb_gadget_stop(udc->gadget, udc->driver);
 219         }
 220
 221         udc->driver = NULL;
 222         udc->dev.driver = NULL;
 223 }
 224
 225 /**
 226  * usb_del_gadget_udc - deletes @udc from udc_list
 227  * @gadget: the gadget to be removed.
 228  *
 229  * This, will call usb_gadget_unregister_driver() if
 230  * the @udc is still busy.
 231  */
 232 void usb_del_gadget_udc(struct usb_gadget *gadget)
 233 {
 234         struct usb_udc          *udc = NULL;
 235
 236         mutex_lock(&udc_lock);
 237         list_for_each_entry(udc, &udc_list, list)
 238                 if (udc->gadget == gadget)
 239                         goto found;
 240
 241         dev_err(gadget->dev.parent, "gadget not registered.\n");
 242         mutex_unlock(&udc_lock);
 243
 244         return;
 245
 246 found:
 247         dev_vdbg(gadget->dev.parent, "unregistering gadget\n");
 248
 249         list_del(&udc->list);
 250         mutex_unlock(&udc_lock);
 251
 252         if (udc->driver)
 253                 usb_gadget_remove_driver(udc);
 254
 255         kobject_uevent(&udc->dev.kobj, KOBJ_REMOVE);
 256         device_unregister(&udc->dev);
 257 }
 258 EXPORT_SYMBOL_GPL(usb_del_gadget_udc);
 259
 260 /* ------------------------------------------------------------------------- */
 261
 262 int usb_gadget_probe_driver(struct usb_gadget_driver *driver,
 263                 int (*bind)(struct usb_gadget *))
 264 {
 265         struct usb_udc          *udc = NULL;
 266         int                     ret;
 267
 268         if (!driver || !bind || !driver->setup)
 269                 return -EINVAL;
 270
 271         mutex_lock(&udc_lock);
 272         list_for_each_entry(udc, &udc_list, list) {
 273                 /* For now we take the first one */
 274                 if (!udc->driver)
 275                         goto found;
 276         }
 277
 278         pr_debug("couldn't find an available UDC\n");
 279         mutex_unlock(&udc_lock);
 280         return -ENODEV;
 281
 282 found:
 283         dev_dbg(&udc->dev, "registering UDC driver [%s]\n",
 284                         driver->function);
 285
 286         udc->driver = driver;
 287         udc->dev.driver = &driver->driver;
 288
 289         if (udc_is_newstyle(udc)) {
 290                 ret = bind(udc->gadget);
 291                 if (ret)
 292                         goto err1;
 293                 ret = usb_gadget_udc_start(udc->gadget, driver);
 294                 if (ret) {
 295                         driver->unbind(udc->gadget);
 296                         goto err1;
 297                 }
 298                 usb_gadget_connect(udc->gadget);
 299         } else {
 300
 301                 ret = usb_gadget_start(udc->gadget, driver, bind);
 302                 if (ret)
 303                         goto err1;
 304
 305         }
 306
 307         kobject_uevent(&udc->dev.kobj, KOBJ_CHANGE);
 308         mutex_unlock(&udc_lock);
 309         return 0;
 310
 311 err1:
 312         dev_err(&udc->dev, "failed to start %s: %d\n",
 313                         udc->driver->function, ret);
 314         udc->driver = NULL;
 315         udc->dev.driver = NULL;
 316         mutex_unlock(&udc_lock);
 317         return ret;
 318 }
 319 EXPORT_SYMBOL_GPL(usb_gadget_probe_driver);
 320
 321 int usb_gadget_unregister_driver(struct usb_gadget_driver *driver)
 322 {
 323         struct usb_udc          *udc = NULL;
 324         int                     ret = -ENODEV;
 325
 326         if (!driver || !driver->unbind)
 327                 return -EINVAL;
 328
 329         mutex_lock(&udc_lock);
 330         list_for_each_entry(udc, &udc_list, list)
 331                 if (udc->driver == driver) {
 332                         usb_gadget_remove_driver(udc);
 333                         ret = 0;
 334                         break;
 335                 }
 336
 337         mutex_unlock(&udc_lock);
 338         return ret;
 339 }
 340 EXPORT_SYMBOL_GPL(usb_gadget_unregister_driver);
 341
 342 /* ------------------------------------------------------------------------- */
 343
 344 static ssize_t usb_udc_srp_store(struct device *dev,
 345                 struct device_attribute *attr, const char *buf, size_t n)
 346 {
 347         struct usb_udc          *udc = container_of(dev, struct usb_udc, dev);
 348
 349         if (sysfs_streq(buf, "1"))
 350                 usb_gadget_wakeup(udc->gadget);
 351
 352         return n;
 353 }
 354 static DEVICE_ATTR(srp, S_IWUSR, NULL, usb_udc_srp_store);
 355
 356 static ssize_t usb_udc_softconn_store(struct device *dev,
 357                 struct device_attribute *attr, const char *buf, size_t n)
 358 {
 359         struct usb_udc          *udc = container_of(dev, struct usb_udc, dev);
 360
 361         if (sysfs_streq(buf, "connect")) {
 362                 usb_gadget_connect(udc->gadget);
 363         } else if (sysfs_streq(buf, "disconnect")) {
 364                 usb_gadget_disconnect(udc->gadget);
 365         } else {
 366                 dev_err(dev, "unsupported command '%s'\n", buf);
 367                 return -EINVAL;
 368         }
 369
 370         return n;
 371 }
 372 static DEVICE_ATTR(soft_connect, S_IWUSR, NULL, usb_udc_softconn_store);
 373
 374 #define USB_UDC_SPEED_ATTR(name, param)                                 \
 375 ssize_t usb_udc_##param##_show(struct device *dev,                      \
 376                 struct device_attribute *attr, char *buf)               \
 377 {                                                                       \
 378         struct usb_udc *udc = container_of(dev, struct usb_udc, dev);   \
 379         return snprintf(buf, PAGE_SIZE, "%s\n",                         \
 380                         usb_speed_string(udc->gadget->param));          \
 381 }                                                                       \
 382 static DEVICE_ATTR(name, S_IRUSR, usb_udc_##param##_show, NULL)
 383
 384 static USB_UDC_SPEED_ATTR(current_speed, speed);
 385 static USB_UDC_SPEED_ATTR(maximum_speed, max_speed);
 386
 387 /* TODO: Scheduled for removal in 3.8. */
 388 static ssize_t usb_udc_is_dualspeed_show(struct device *dev,
 389                 struct device_attribute *attr, char *buf)
 390 {
 391         struct usb_udc          *udc = container_of(dev, struct usb_udc, dev);
 392         return snprintf(buf, PAGE_SIZE, "%d\n",
 393                         gadget_is_dualspeed(udc->gadget));
 394 }
 395 static DEVICE_ATTR(is_dualspeed, S_IRUSR, usb_udc_is_dualspeed_show, NULL);
 396
 397 #define USB_UDC_ATTR(name)                                      \
 398 ssize_t usb_udc_##name##_show(struct device *dev,               \
 399                 struct device_attribute *attr, char *buf)       \
 400 {                                                               \
 401         struct usb_udc          *udc = container_of(dev, struct usb_udc, dev); \
 402         struct usb_gadget       *gadget = udc->gadget;          \
 403                                                                 \
 404         return snprintf(buf, PAGE_SIZE, "%d\n", gadget->name);  \
 405 }                                                               \
 406 static DEVICE_ATTR(name, S_IRUGO, usb_udc_##name##_show, NULL)
 407
 408 static USB_UDC_ATTR(is_otg);
 409 static USB_UDC_ATTR(is_a_peripheral);
 410 static USB_UDC_ATTR(b_hnp_enable);
 411 static USB_UDC_ATTR(a_hnp_support);
 412 static USB_UDC_ATTR(a_alt_hnp_support);
 413
 414 static struct attribute *usb_udc_attrs[] = {
 415         &dev_attr_srp.attr,
 416         &dev_attr_soft_connect.attr,
 417         &dev_attr_current_speed.attr,
 418         &dev_attr_maximum_speed.attr,
 419
 420         &dev_attr_is_dualspeed.attr,
 421         &dev_attr_is_otg.attr,
 422         &dev_attr_is_a_peripheral.attr,
 423         &dev_attr_b_hnp_enable.attr,
 424         &dev_attr_a_hnp_support.attr,
 425         &dev_attr_a_alt_hnp_support.attr,
 426         NULL,
 427 };
 428
 429 static const struct attribute_group usb_udc_attr_group = {
 430         .attrs = usb_udc_attrs,
 431 };
 432
 433 static const struct attribute_group *usb_udc_attr_groups[] = {
 434         &usb_udc_attr_group,
 435         NULL,
 436 };
 437
 438 static int usb_udc_uevent(struct device *dev, struct kobj_uevent_env *env)
 439 {
 440         struct usb_udc          *udc = container_of(dev, struct usb_udc, dev);
 441         int                     ret;
 442
 443         ret = add_uevent_var(env, "USB_UDC_NAME=%s", udc->gadget->name);
 444         if (ret) {
 445                 dev_err(dev, "failed to add uevent USB_UDC_NAME\n");
 446                 return ret;
 447         }
 448
 449         if (udc->driver) {
 450                 ret = add_uevent_var(env, "USB_UDC_DRIVER=%s",
 451                                 udc->driver->function);
 452                 if (ret) {
 453                         dev_err(dev, "failed to add uevent USB_UDC_DRIVER\n");
 454                         return ret;
 455                 }
 456         }
 457
 458         return 0;
 459 }
 460
 461 static int __init usb_udc_init(void)
 462 {
 463         udc_class = class_create(THIS_MODULE, "udc");
 464         if (IS_ERR(udc_class)) {
 465                 pr_err("failed to create udc class --> %ld\n",
 466                                 PTR_ERR(udc_class));
 467                 return PTR_ERR(udc_class);
 468         }
 469
 470         udc_class->dev_uevent = usb_udc_uevent;
 471         return 0;
 472 }
 473 subsys_initcall(usb_udc_init);
 474
 475 static void __exit usb_udc_exit(void)
 476 {
 477         class_destroy(udc_class);
 478 }
 479 module_exit(usb_udc_exit);
 480
 481 MODULE_DESCRIPTION("UDC Framework");
 482 MODULE_AUTHOR("Felipe Balbi <balbi@ti.com>");
 483 MODULE_LICENSE("GPL v2");