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                 phy = ERR_PTR(-EPROBE_DEFER);
 195                 devres_free(ptr);
 196                 goto err1;
 197         }
 198
 199         *ptr = phy;
 200         devres_add(dev, ptr);
 201
 202         get_device(phy->dev);
 203
 204 err1:
 205         spin_unlock_irqrestore(&phy_lock, flags);
 206
 207 err0:
 208         of_node_put(node);
 209
 210         return phy;
 211 }
 212 EXPORT_SYMBOL_GPL(devm_usb_get_phy_by_phandle);
 213
 214 /**
 215  * usb_get_phy_dev - find the USB PHY
 216  * @dev - device that requests this phy
 217  * @index - the index of the phy
 218  *
 219  * Returns the phy driver, after getting a refcount to it; or
 220  * -ENODEV if there is no such phy.  The caller is responsible for
 221  * calling usb_put_phy() to release that count.
 222  *
 223  * For use by USB host and peripheral drivers.
 224  */
 225 struct usb_phy *usb_get_phy_dev(struct device *dev, u8 index)
 226 {
 227         struct usb_phy  *phy = NULL;
 228         unsigned long   flags;
 229
 230         spin_lock_irqsave(&phy_lock, flags);
 231
 232         phy = __usb_find_phy_dev(dev, &phy_bind_list, index);
 233         if (IS_ERR(phy) || !try_module_get(phy->dev->driver->owner)) {
 234                 dev_dbg(dev, "unable to find transceiver\n");
 235                 goto err0;
 236         }
 237
 238         get_device(phy->dev);
 239
 240 err0:
 241         spin_unlock_irqrestore(&phy_lock, flags);
 242
 243         return phy;
 244 }
 245 EXPORT_SYMBOL_GPL(usb_get_phy_dev);
 246
 247 /**
 248  * devm_usb_get_phy_dev - find the USB PHY using device ptr and index
 249  * @dev - device that requests this phy
 250  * @index - the index of the phy
 251  *
 252  * Gets the phy using usb_get_phy_dev(), and associates a device with it using
 253  * devres. On driver detach, release function is invoked on the devres data,
 254  * then, devres data is freed.
 255  *
 256  * For use by USB host and peripheral drivers.
 257  */
 258 struct usb_phy *devm_usb_get_phy_dev(struct device *dev, u8 index)
 259 {
 260         struct usb_phy **ptr, *phy;
 261
 262         ptr = devres_alloc(devm_usb_phy_release, sizeof(*ptr), GFP_KERNEL);
 263         if (!ptr)
 264                 return NULL;
 265
 266         phy = usb_get_phy_dev(dev, index);
 267         if (!IS_ERR(phy)) {
 268                 *ptr = phy;
 269                 devres_add(dev, ptr);
 270         } else
 271                 devres_free(ptr);
 272
 273         return phy;
 274 }
 275 EXPORT_SYMBOL_GPL(devm_usb_get_phy_dev);
 276
 277 /**
 278  * devm_usb_put_phy - release the USB PHY
 279  * @dev - device that wants to release this phy
 280  * @phy - the phy returned by devm_usb_get_phy()
 281  *
 282  * destroys the devres associated with this phy and invokes usb_put_phy
 283  * to release the phy.
 284  *
 285  * For use by USB host and peripheral drivers.
 286  */
 287 void devm_usb_put_phy(struct device *dev, struct usb_phy *phy)
 288 {
 289         int r;
 290
 291         r = devres_destroy(dev, devm_usb_phy_release, devm_usb_phy_match, phy);
 292         dev_WARN_ONCE(dev, r, "couldn't find PHY resource\n");
 293 }
 294 EXPORT_SYMBOL_GPL(devm_usb_put_phy);
 295
 296 /**
 297  * usb_put_phy - release the USB PHY
 298  * @x: the phy returned by usb_get_phy()
 299  *
 300  * Releases a refcount the caller received from usb_get_phy().
 301  *
 302  * For use by USB host and peripheral drivers.
 303  */
 304 void usb_put_phy(struct usb_phy *x)
 305 {
 306         if (x) {
 307                 struct module *owner = x->dev->driver->owner;
 308
 309                 put_device(x->dev);
 310                 module_put(owner);
 311         }
 312 }
 313 EXPORT_SYMBOL_GPL(usb_put_phy);
 314
 315 /**
 316  * usb_add_phy - declare the USB PHY
 317  * @x: the USB phy to be used; or NULL
 318  * @type - the type of this PHY
 319  *
 320  * This call is exclusively for use by phy drivers, which
 321  * coordinate the activities of drivers for host and peripheral
 322  * controllers, and in some cases for VBUS current regulation.
 323  */
 324 int usb_add_phy(struct usb_phy *x, enum usb_phy_type type)
 325 {
 326         int             ret = 0;
 327         unsigned long   flags;
 328         struct usb_phy  *phy;
 329
 330         if (x->type != USB_PHY_TYPE_UNDEFINED) {
 331                 dev_err(x->dev, "not accepting initialized PHY %s\n", x->label);
 332                 return -EINVAL;
 333         }
 334
 335         ATOMIC_INIT_NOTIFIER_HEAD(&x->notifier);
 336
 337         spin_lock_irqsave(&phy_lock, flags);
 338
 339         list_for_each_entry(phy, &phy_list, head) {
 340                 if (phy->type == type) {
 341                         ret = -EBUSY;
 342                         dev_err(x->dev, "transceiver type %s already exists\n",
 343                                                 usb_phy_type_string(type));
 344                         goto out;
 345                 }
 346         }
 347
 348         x->type = type;
 349         list_add_tail(&x->head, &phy_list);
 350
 351 out:
 352         spin_unlock_irqrestore(&phy_lock, flags);
 353         return ret;
 354 }
 355 EXPORT_SYMBOL_GPL(usb_add_phy);
 356
 357 /**
 358  * usb_add_phy_dev - declare the USB PHY
 359  * @x: the USB phy to be used; or NULL
 360  *
 361  * This call is exclusively for use by phy drivers, which
 362  * coordinate the activities of drivers for host and peripheral
 363  * controllers, and in some cases for VBUS current regulation.
 364  */
 365 int usb_add_phy_dev(struct usb_phy *x)
 366 {
 367         struct usb_phy_bind *phy_bind;
 368         unsigned long flags;
 369
 370         if (!x->dev) {
 371                 dev_err(x->dev, "no device provided for PHY\n");
 372                 return -EINVAL;
 373         }
 374
 375         ATOMIC_INIT_NOTIFIER_HEAD(&x->notifier);
 376
 377         spin_lock_irqsave(&phy_lock, flags);
 378         list_for_each_entry(phy_bind, &phy_bind_list, list)
 379                 if (!(strcmp(phy_bind->phy_dev_name, dev_name(x->dev))))
 380                         phy_bind->phy = x;
 381
 382         list_add_tail(&x->head, &phy_list);
 383
 384         spin_unlock_irqrestore(&phy_lock, flags);
 385         return 0;
 386 }
 387 EXPORT_SYMBOL_GPL(usb_add_phy_dev);
 388
 389 /**
 390  * usb_remove_phy - remove the OTG PHY
 391  * @x: the USB OTG PHY to be removed;
 392  *
 393  * This reverts the effects of usb_add_phy
 394  */
 395 void usb_remove_phy(struct usb_phy *x)
 396 {
 397         unsigned long   flags;
 398         struct usb_phy_bind *phy_bind;
 399
 400         spin_lock_irqsave(&phy_lock, flags);
 401         if (x) {
 402                 list_for_each_entry(phy_bind, &phy_bind_list, list)
 403                         if (phy_bind->phy == x)
 404                                 phy_bind->phy = NULL;
 405                 list_del(&x->head);
 406         }
 407         spin_unlock_irqrestore(&phy_lock, flags);
 408 }
 409 EXPORT_SYMBOL_GPL(usb_remove_phy);
 410
 411 /**
 412  * usb_bind_phy - bind the phy and the controller that uses the phy
 413  * @dev_name: the device name of the device that will bind to the phy
 414  * @index: index to specify the port number
 415  * @phy_dev_name: the device name of the phy
 416  *
 417  * Fills the phy_bind structure with the dev_name and phy_dev_name. This will
 418  * be used when the phy driver registers the phy and when the controller
 419  * requests this phy.
 420  *
 421  * To be used by platform specific initialization code.
 422  */
 423 int usb_bind_phy(const char *dev_name, u8 index,
 424                                 const char *phy_dev_name)
 425 {
 426         struct usb_phy_bind *phy_bind;
 427         unsigned long flags;
 428
 429         phy_bind = kzalloc(sizeof(*phy_bind), GFP_KERNEL);
 430         if (!phy_bind)
 431                 return -ENOMEM;
 432
 433         phy_bind->dev_name = dev_name;
 434         phy_bind->phy_dev_name = phy_dev_name;
 435         phy_bind->index = index;
 436
 437         spin_lock_irqsave(&phy_lock, flags);
 438         list_add_tail(&phy_bind->list, &phy_bind_list);
 439         spin_unlock_irqrestore(&phy_lock, flags);
 440
 441         return 0;
 442 }
 443 EXPORT_SYMBOL_GPL(usb_bind_phy);