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