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