drivers/usb/phy/phy.c

   1 /*
   2  * phy.c -- USB phy handling
   3  *
   4  * Copyright (C) 2004-2013 Texas Instruments
   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 #include <linux/kernel.h>
  12 #include <linux/export.h>
  13 #include <linux/err.h>
  14 #include <linux/device.h>
  15 #include <linux/module.h>
  16 #include <linux/slab.h>
  17 #include <linux/of.h>
  18
  19 #include <linux/usb/phy.h>
  20
  21 static LIST_HEAD(phy_list);
  22 static LIST_HEAD(phy_bind_list);
  23 static DEFINE_SPINLOCK(phy_lock);
  24
  25 struct phy_devm {
  26         struct usb_phy *phy;
  27         struct notifier_block *nb;
  28 };
  29
  30 static struct usb_phy *__usb_find_phy(struct list_head *list,
  31         enum usb_phy_type type)
  32 {
  33         struct usb_phy  *phy = NULL;
  34
  35         list_for_each_entry(phy, list, head) {
  36                 if (phy->type != type)
  37                         continue;
  38
  39                 return phy;
  40         }
  41
  42         return ERR_PTR(-ENODEV);
  43 }
  44
  45 static struct usb_phy *__usb_find_phy_dev(struct device *dev,
  46         struct list_head *list, u8 index)
  47 {
  48         struct usb_phy_bind *phy_bind = NULL;
  49
  50         list_for_each_entry(phy_bind, list, list) {
  51                 if (!(strcmp(phy_bind->dev_name, dev_name(dev))) &&
  52                                 phy_bind->index == index) {
  53                         if (phy_bind->phy)
  54                                 return phy_bind->phy;
  55                         else
  56                                 return ERR_PTR(-EPROBE_DEFER);
  57                 }
  58         }
  59
  60         return ERR_PTR(-ENODEV);
  61 }
  62
  63 static struct usb_phy *__of_usb_find_phy(struct device_node *node)
  64 {
  65         struct usb_phy  *phy;
  66
  67         if (!of_device_is_available(node))
  68                 return ERR_PTR(-ENODEV);
  69
  70         list_for_each_entry(phy, &phy_list, head) {
  71                 if (node != phy->dev->of_node)
  72                         continue;
  73
  74                 return phy;
  75         }
  76
  77         return ERR_PTR(-EPROBE_DEFER);
  78 }
  79
  80 static void devm_usb_phy_release(struct device *dev, void *res)
  81 {
  82         struct usb_phy *phy = *(struct usb_phy **)res;
  83
  84         usb_put_phy(phy);
  85 }
  86
  87 static void devm_usb_phy_release2(struct device *dev, void *_res)
  88 {
  89         struct phy_devm *res = _res;
  90
  91         if (res->nb)
  92                 usb_unregister_notifier(res->phy, res->nb);
  93         usb_put_phy(res->phy);
  94 }
  95
  96 static int devm_usb_phy_match(struct device *dev, void *res, void *match_data)
  97 {
  98         struct usb_phy **phy = res;
  99
 100         return *phy == match_data;
 101 }
 102
 103 /**
 104  * devm_usb_get_phy - find the USB PHY
 105  * @dev - device that requests this phy
 106  * @type - the type of the phy the controller requires
 107  *
 108  * Gets the phy using usb_get_phy(), and associates a device with it using
 109  * devres. On driver detach, release function is invoked on the devres data,
 110  * then, devres data is freed.
 111  *
 112  * For use by USB host and peripheral drivers.
 113  */
 114 struct usb_phy *devm_usb_get_phy(struct device *dev, enum usb_phy_type type)
 115 {
 116         struct usb_phy **ptr, *phy;
 117
 118         ptr = devres_alloc(devm_usb_phy_release, sizeof(*ptr), GFP_KERNEL);
 119         if (!ptr)
 120                 return ERR_PTR(-ENOMEM);
 121
 122         phy = usb_get_phy(type);
 123         if (!IS_ERR(phy)) {
 124                 *ptr = phy;
 125                 devres_add(dev, ptr);
 126         } else
 127                 devres_free(ptr);
 128
 129         return phy;
 130 }
 131 EXPORT_SYMBOL_GPL(devm_usb_get_phy);
 132
 133 /**
 134  * usb_get_phy - find the USB PHY
 135  * @type - the type of the phy the controller requires
 136  *
 137  * Returns the phy driver, after getting a refcount to it; or
 138  * -ENODEV if there is no such phy.  The caller is responsible for
 139  * calling usb_put_phy() to release that count.
 140  *
 141  * For use by USB host and peripheral drivers.
 142  */
 143 struct usb_phy *usb_get_phy(enum usb_phy_type type)
 144 {
 145         struct usb_phy  *phy = NULL;
 146         unsigned long   flags;
 147
 148         spin_lock_irqsave(&phy_lock, flags);
 149
 150         phy = __usb_find_phy(&phy_list, type);
 151         if (IS_ERR(phy) || !try_module_get(phy->dev->driver->owner)) {
 152                 pr_debug("PHY: unable to find transceiver of type %s\n",
 153                         usb_phy_type_string(type));
 154                 if (!IS_ERR(phy))
 155                         phy = ERR_PTR(-ENODEV);
 156
 157                 goto err0;
 158         }
 159
 160         get_device(phy->dev);
 161
 162 err0:
 163         spin_unlock_irqrestore(&phy_lock, flags);
 164
 165         return phy;
 166 }
 167 EXPORT_SYMBOL_GPL(usb_get_phy);
 168
 169 /**
 170  * devm_usb_get_phy_by_node - find the USB PHY by device_node
 171  * @dev - device that requests this phy
 172  * @node - the device_node for the phy device.
 173  * @nb - a notifier_block to register with the phy.
 174  *
 175  * Returns the phy driver associated with the given device_node,
 176  * after getting a refcount to it, -ENODEV if there is no such phy or
 177  * -EPROBE_DEFER if the device is not yet loaded. While at that, it
 178  * also associates the device with
 179  * the phy using devres. On driver detach, release function is invoked
 180  * on the devres data, then, devres data is freed.
 181  *
 182  * For use by peripheral drivers for devices related to a phy,
 183  * such as a charger.
 184  */
 185 struct  usb_phy *devm_usb_get_phy_by_node(struct device *dev,
 186                                           struct device_node *node,
 187                                           struct notifier_block *nb)
 188 {
 189         struct usb_phy  *phy = ERR_PTR(-ENOMEM);
 190         struct phy_devm *ptr;
 191         unsigned long   flags;
 192
 193         ptr = devres_alloc(devm_usb_phy_release2, sizeof(*ptr), GFP_KERNEL);
 194         if (!ptr) {
 195                 dev_dbg(dev, "failed to allocate memory for devres\n");
 196                 goto err0;
 197         }
 198
 199         spin_lock_irqsave(&phy_lock, flags);
 200
 201         phy = __of_usb_find_phy(node);
 202         if (IS_ERR(phy)) {
 203                 devres_free(ptr);
 204                 goto err1;
 205         }
 206
 207         if (!try_module_get(phy->dev->driver->owner)) {
 208                 phy = ERR_PTR(-ENODEV);
 209                 devres_free(ptr);
 210                 goto err1;
 211         }
 212         if (nb)
 213                 usb_register_notifier(phy, nb);
 214         ptr->phy = phy;
 215         ptr->nb = nb;
 216         devres_add(dev, ptr);
 217
 218         get_device(phy->dev);
 219
 220 err1:
 221         spin_unlock_irqrestore(&phy_lock, flags);
 222
 223 err0:
 224
 225         return phy;
 226 }
 227 EXPORT_SYMBOL_GPL(devm_usb_get_phy_by_node);
 228
 229 /**
 230  * devm_usb_get_phy_by_phandle - find the USB PHY by phandle
 231  * @dev - device that requests this phy
 232  * @phandle - name of the property holding the phy phandle value
 233  * @index - the index of the phy
 234  *
 235  * Returns the phy driver associated with the given phandle value,
 236  * after getting a refcount to it, -ENODEV if there is no such phy or
 237  * -EPROBE_DEFER if there is a phandle to the phy, but the device is
 238  * not yet loaded. While at that, it also associates the device with
 239  * the phy using devres. On driver detach, release function is invoked
 240  * on the devres data, then, devres data is freed.
 241  *
 242  * For use by USB host and peripheral drivers.
 243  */
 244 struct usb_phy *devm_usb_get_phy_by_phandle(struct device *dev,
 245         const char *phandle, u8 index)
 246 {
 247         struct device_node *node;
 248         struct usb_phy  *phy;
 249
 250         if (!dev->of_node) {
 251                 dev_dbg(dev, "device does not have a device node entry\n");
 252                 return ERR_PTR(-EINVAL);
 253         }
 254
 255         node = of_parse_phandle(dev->of_node, phandle, index);
 256         if (!node) {
 257                 dev_dbg(dev, "failed to get %s phandle in %s node\n", phandle,
 258                         dev->of_node->full_name);
 259                 return ERR_PTR(-ENODEV);
 260         }
 261         phy = devm_usb_get_phy_by_node(dev, node, NULL);
 262         of_node_put(node);
 263         return phy;
 264 }
 265 EXPORT_SYMBOL_GPL(devm_usb_get_phy_by_phandle);
 266
 267 /**
 268  * usb_get_phy_dev - find the USB PHY
 269  * @dev - device that requests this phy
 270  * @index - the index of the phy
 271  *
 272  * Returns the phy driver, after getting a refcount to it; or
 273  * -ENODEV if there is no such phy.  The caller is responsible for
 274  * calling usb_put_phy() to release that count.
 275  *
 276  * For use by USB host and peripheral drivers.
 277  */
 278 struct usb_phy *usb_get_phy_dev(struct device *dev, u8 index)
 279 {
 280         struct usb_phy  *phy = NULL;
 281         unsigned long   flags;
 282
 283         spin_lock_irqsave(&phy_lock, flags);
 284
 285         phy = __usb_find_phy_dev(dev, &phy_bind_list, index);
 286         if (IS_ERR(phy) || !try_module_get(phy->dev->driver->owner)) {
 287                 dev_dbg(dev, "unable to find transceiver\n");
 288                 if (!IS_ERR(phy))
 289                         phy = ERR_PTR(-ENODEV);
 290
 291                 goto err0;
 292         }
 293
 294         get_device(phy->dev);
 295
 296 err0:
 297         spin_unlock_irqrestore(&phy_lock, flags);
 298
 299         return phy;
 300 }
 301 EXPORT_SYMBOL_GPL(usb_get_phy_dev);
 302
 303 /**
 304  * devm_usb_get_phy_dev - find the USB PHY using device ptr and index
 305  * @dev - device that requests this phy
 306  * @index - the index of the phy
 307  *
 308  * Gets the phy using usb_get_phy_dev(), and associates a device with it using
 309  * devres. On driver detach, release function is invoked on the devres data,
 310  * then, devres data is freed.
 311  *
 312  * For use by USB host and peripheral drivers.
 313  */
 314 struct usb_phy *devm_usb_get_phy_dev(struct device *dev, u8 index)
 315 {
 316         struct usb_phy **ptr, *phy;
 317
 318         ptr = devres_alloc(devm_usb_phy_release, sizeof(*ptr), GFP_KERNEL);
 319         if (!ptr)
 320                 return NULL;
 321
 322         phy = usb_get_phy_dev(dev, index);
 323         if (!IS_ERR(phy)) {
 324                 *ptr = phy;
 325                 devres_add(dev, ptr);
 326         } else
 327                 devres_free(ptr);
 328
 329         return phy;
 330 }
 331 EXPORT_SYMBOL_GPL(devm_usb_get_phy_dev);
 332
 333 /**
 334  * devm_usb_put_phy - release the USB PHY
 335  * @dev - device that wants to release this phy
 336  * @phy - the phy returned by devm_usb_get_phy()
 337  *
 338  * destroys the devres associated with this phy and invokes usb_put_phy
 339  * to release the phy.
 340  *
 341  * For use by USB host and peripheral drivers.
 342  */
 343 void devm_usb_put_phy(struct device *dev, struct usb_phy *phy)
 344 {
 345         int r;
 346
 347         r = devres_destroy(dev, devm_usb_phy_release, devm_usb_phy_match, phy);
 348         dev_WARN_ONCE(dev, r, "couldn't find PHY resource\n");
 349 }
 350 EXPORT_SYMBOL_GPL(devm_usb_put_phy);
 351
 352 /**
 353  * usb_put_phy - release the USB PHY
 354  * @x: the phy returned by usb_get_phy()
 355  *
 356  * Releases a refcount the caller received from usb_get_phy().
 357  *
 358  * For use by USB host and peripheral drivers.
 359  */
 360 void usb_put_phy(struct usb_phy *x)
 361 {
 362         if (x) {
 363                 struct module *owner = x->dev->driver->owner;
 364
 365                 put_device(x->dev);
 366                 module_put(owner);
 367         }
 368 }
 369 EXPORT_SYMBOL_GPL(usb_put_phy);
 370
 371 /**
 372  * usb_add_phy - declare the USB PHY
 373  * @x: the USB phy to be used; or NULL
 374  * @type - the type of this PHY
 375  *
 376  * This call is exclusively for use by phy drivers, which
 377  * coordinate the activities of drivers for host and peripheral
 378  * controllers, and in some cases for VBUS current regulation.
 379  */
 380 int usb_add_phy(struct usb_phy *x, enum usb_phy_type type)
 381 {
 382         int             ret = 0;
 383         unsigned long   flags;
 384         struct usb_phy  *phy;
 385
 386         if (x->type != USB_PHY_TYPE_UNDEFINED) {
 387                 dev_err(x->dev, "not accepting initialized PHY %s\n", x->label);
 388                 return -EINVAL;
 389         }
 390
 391         ATOMIC_INIT_NOTIFIER_HEAD(&x->notifier);
 392
 393         spin_lock_irqsave(&phy_lock, flags);
 394
 395         list_for_each_entry(phy, &phy_list, head) {
 396                 if (phy->type == type) {
 397                         ret = -EBUSY;
 398                         dev_err(x->dev, "transceiver type %s already exists\n",
 399                                                 usb_phy_type_string(type));
 400                         goto out;
 401                 }
 402         }
 403
 404         x->type = type;
 405         list_add_tail(&x->head, &phy_list);
 406
 407 out:
 408         spin_unlock_irqrestore(&phy_lock, flags);
 409         return ret;
 410 }
 411 EXPORT_SYMBOL_GPL(usb_add_phy);
 412
 413 /**
 414  * usb_add_phy_dev - declare the USB PHY
 415  * @x: the USB phy to be used; or NULL
 416  *
 417  * This call is exclusively for use by phy drivers, which
 418  * coordinate the activities of drivers for host and peripheral
 419  * controllers, and in some cases for VBUS current regulation.
 420  */
 421 int usb_add_phy_dev(struct usb_phy *x)
 422 {
 423         struct usb_phy_bind *phy_bind;
 424         unsigned long flags;
 425
 426         if (!x->dev) {
 427                 dev_err(x->dev, "no device provided for PHY\n");
 428                 return -EINVAL;
 429         }
 430
 431         ATOMIC_INIT_NOTIFIER_HEAD(&x->notifier);
 432
 433         spin_lock_irqsave(&phy_lock, flags);
 434         list_for_each_entry(phy_bind, &phy_bind_list, list)
 435                 if (!(strcmp(phy_bind->phy_dev_name, dev_name(x->dev))))
 436                         phy_bind->phy = x;
 437
 438         list_add_tail(&x->head, &phy_list);
 439
 440         spin_unlock_irqrestore(&phy_lock, flags);
 441         return 0;
 442 }
 443 EXPORT_SYMBOL_GPL(usb_add_phy_dev);
 444
 445 /**
 446  * usb_remove_phy - remove the OTG PHY
 447  * @x: the USB OTG PHY to be removed;
 448  *
 449  * This reverts the effects of usb_add_phy
 450  */
 451 void usb_remove_phy(struct usb_phy *x)
 452 {
 453         unsigned long   flags;
 454         struct usb_phy_bind *phy_bind;
 455
 456         spin_lock_irqsave(&phy_lock, flags);
 457         if (x) {
 458                 list_for_each_entry(phy_bind, &phy_bind_list, list)
 459                         if (phy_bind->phy == x)
 460                                 phy_bind->phy = NULL;
 461                 list_del(&x->head);
 462         }
 463         spin_unlock_irqrestore(&phy_lock, flags);
 464 }
 465 EXPORT_SYMBOL_GPL(usb_remove_phy);
 466
 467 /**
 468  * usb_bind_phy - bind the phy and the controller that uses the phy
 469  * @dev_name: the device name of the device that will bind to the phy
 470  * @index: index to specify the port number
 471  * @phy_dev_name: the device name of the phy
 472  *
 473  * Fills the phy_bind structure with the dev_name and phy_dev_name. This will
 474  * be used when the phy driver registers the phy and when the controller
 475  * requests this phy.
 476  *
 477  * To be used by platform specific initialization code.
 478  */
 479 int usb_bind_phy(const char *dev_name, u8 index,
 480                                 const char *phy_dev_name)
 481 {
 482         struct usb_phy_bind *phy_bind;
 483         unsigned long flags;
 484
 485         phy_bind = kzalloc(sizeof(*phy_bind), GFP_KERNEL);
 486         if (!phy_bind)
 487                 return -ENOMEM;
 488
 489         phy_bind->dev_name = dev_name;
 490         phy_bind->phy_dev_name = phy_dev_name;
 491         phy_bind->index = index;
 492
 493         spin_lock_irqsave(&phy_lock, flags);
 494         list_add_tail(&phy_bind->list, &phy_bind_list);
 495         spin_unlock_irqrestore(&phy_lock, flags);
 496
 497         return 0;
 498 }
 499 EXPORT_SYMBOL_GPL(usb_bind_phy);
 500
 501 /**
 502  * usb_phy_set_event - set event to phy event
 503  * @x: the phy returned by usb_get_phy();
 504  *
 505  * This sets event to phy event
 506  */
 507 void usb_phy_set_event(struct usb_phy *x, unsigned long event)
 508 {
 509         x->last_event = event;
 510 }
 511 EXPORT_SYMBOL_GPL(usb_phy_set_event);