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