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