drivers/usb/otg/otg.c

   1 /*
   2  * otg.c -- USB OTG utility code
   3  *
   4  * Copyright (C) 2004 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
  12 #include <linux/kernel.h>
  13 #include <linux/export.h>
  14 #include <linux/err.h>
  15 #include <linux/device.h>
  16 #include <linux/module.h>
  17 #include <linux/slab.h>
  18 #include <linux/of.h>
  19
  20 #include <linux/usb/otg.h>
  21
  22 static LIST_HEAD(phy_list);
  23 static LIST_HEAD(phy_bind_list);
  24 static DEFINE_SPINLOCK(phy_lock);
  25
  26 static struct usb_phy *__usb_find_phy(struct list_head *list,
  27         enum usb_phy_type type)
  28 {
  29         struct usb_phy  *phy = NULL;
  30
  31         list_for_each_entry(phy, list, head) {
  32                 if (phy->type != type)
  33                         continue;
  34
  35                 return phy;
  36         }
  37
  38         return ERR_PTR(-ENODEV);
  39 }
  40
  41 static struct usb_phy *__usb_find_phy_dev(struct device *dev,
  42         struct list_head *list, u8 index)
  43 {
  44         struct usb_phy_bind *phy_bind = NULL;
  45
  46         list_for_each_entry(phy_bind, list, list) {
  47                 if (!(strcmp(phy_bind->dev_name, dev_name(dev))) &&
  48                                 phy_bind->index == index) {
  49                         if (phy_bind->phy)
  50                                 return phy_bind->phy;
  51                         else
  52                                 return ERR_PTR(-EPROBE_DEFER);
  53                 }
  54         }
  55
  56         return ERR_PTR(-ENODEV);
  57 }
  58
  59 static struct usb_phy *__of_usb_find_phy(struct device_node *node)
  60 {
  61         struct usb_phy  *phy;
  62
  63         list_for_each_entry(phy, &phy_list, head) {
  64                 if (node != phy->dev->of_node)
  65                         continue;
  66
  67                 return phy;
  68         }
  69
  70         return ERR_PTR(-ENODEV);
  71 }
  72
  73 static void devm_usb_phy_release(struct device *dev, void *res)
  74 {
  75         struct usb_phy *phy = *(struct usb_phy **)res;
  76
  77         usb_put_phy(phy);
  78 }
  79
  80 static int devm_usb_phy_match(struct device *dev, void *res, void *match_data)
  81 {
  82         return res == match_data;
  83 }
  84
  85 /**
  86  * devm_usb_get_phy - find the USB PHY
  87  * @dev - device that requests this phy
  88  * @type - the type of the phy the controller requires
  89  *
  90  * Gets the phy using usb_get_phy(), and associates a device with it using
  91  * devres. On driver detach, release function is invoked on the devres data,
  92  * then, devres data is freed.
  93  *
  94  * For use by USB host and peripheral drivers.
  95  */
  96 struct usb_phy *devm_usb_get_phy(struct device *dev, enum usb_phy_type type)
  97 {
  98         struct usb_phy **ptr, *phy;
  99
 100         ptr = devres_alloc(devm_usb_phy_release, sizeof(*ptr), GFP_KERNEL);
 101         if (!ptr)
 102                 return NULL;
 103
 104         phy = usb_get_phy(type);
 105         if (!IS_ERR(phy)) {
 106                 *ptr = phy;
 107                 devres_add(dev, ptr);
 108         } else
 109                 devres_free(ptr);
 110
 111         return phy;
 112 }
 113 EXPORT_SYMBOL(devm_usb_get_phy);
 114
 115 /**
 116  * usb_get_phy - find the USB PHY
 117  * @type - the type of the phy the controller requires
 118  *
 119  * Returns the phy driver, after getting a refcount to it; or
 120  * -ENODEV if there is no such phy.  The caller is responsible for
 121  * calling usb_put_phy() to release that count.
 122  *
 123  * For use by USB host and peripheral drivers.
 124  */
 125 struct usb_phy *usb_get_phy(enum usb_phy_type type)
 126 {
 127         struct usb_phy  *phy = NULL;
 128         unsigned long   flags;
 129
 130         spin_lock_irqsave(&phy_lock, flags);
 131
 132         phy = __usb_find_phy(&phy_list, type);
 133         if (IS_ERR(phy)) {
 134                 pr_err("unable to find transceiver of type %s\n",
 135                         usb_phy_type_string(type));
 136                 goto err0;
 137         }
 138
 139         get_device(phy->dev);
 140
 141 err0:
 142         spin_unlock_irqrestore(&phy_lock, flags);
 143
 144         return phy;
 145 }
 146 EXPORT_SYMBOL(usb_get_phy);
 147
 148  /**
 149  * devm_usb_get_phy_by_phandle - find the USB PHY by phandle
 150  * @dev - device that requests this phy
 151  * @phandle - name of the property holding the phy phandle value
 152  * @index - the index of the phy
 153  *
 154  * Returns the phy driver associated with the given phandle value,
 155  * after getting a refcount to it, -ENODEV if there is no such phy or
 156  * -EPROBE_DEFER if there is a phandle to the phy, but the device is
 157  * not yet loaded. While at that, it also associates the device with
 158  * the phy using devres. On driver detach, release function is invoked
 159  * on the devres data, then, devres data is freed.
 160  *
 161  * For use by USB host and peripheral drivers.
 162  */
 163 struct usb_phy *devm_usb_get_phy_by_phandle(struct device *dev,
 164         const char *phandle, u8 index)
 165 {
 166         struct usb_phy  *phy = ERR_PTR(-ENOMEM), **ptr;
 167         unsigned long   flags;
 168         struct device_node *node;
 169
 170         if (!dev->of_node) {
 171                 dev_dbg(dev, "device does not have a device node entry\n");
 172                 return ERR_PTR(-EINVAL);
 173         }
 174
 175         node = of_parse_phandle(dev->of_node, phandle, index);
 176         if (!node) {
 177                 dev_dbg(dev, "failed to get %s phandle in %s node\n", phandle,
 178                         dev->of_node->full_name);
 179                 return ERR_PTR(-ENODEV);
 180         }
 181
 182         ptr = devres_alloc(devm_usb_phy_release, sizeof(*ptr), GFP_KERNEL);
 183         if (!ptr) {
 184                 dev_dbg(dev, "failed to allocate memory for devres\n");
 185                 goto err0;
 186         }
 187
 188         spin_lock_irqsave(&phy_lock, flags);
 189
 190         phy = __of_usb_find_phy(node);
 191         if (IS_ERR(phy) || !try_module_get(phy->dev->driver->owner)) {
 192                 phy = ERR_PTR(-EPROBE_DEFER);
 193                 devres_free(ptr);
 194                 goto err1;
 195         }
 196
 197         *ptr = phy;
 198         devres_add(dev, ptr);
 199
 200         get_device(phy->dev);
 201
 202 err1:
 203         spin_unlock_irqrestore(&phy_lock, flags);
 204
 205 err0:
 206         of_node_put(node);
 207
 208         return phy;
 209 }
 210 EXPORT_SYMBOL(devm_usb_get_phy_by_phandle);
 211
 212 /**
 213  * usb_get_phy_dev - find the USB PHY
 214  * @dev - device that requests this phy
 215  * @index - the index of the phy
 216  *
 217  * Returns the phy driver, after getting a refcount to it; or
 218  * -ENODEV if there is no such phy.  The caller is responsible for
 219  * calling usb_put_phy() to release that count.
 220  *
 221  * For use by USB host and peripheral drivers.
 222  */
 223 struct usb_phy *usb_get_phy_dev(struct device *dev, u8 index)
 224 {
 225         struct usb_phy  *phy = NULL;
 226         unsigned long   flags;
 227
 228         spin_lock_irqsave(&phy_lock, flags);
 229
 230         phy = __usb_find_phy_dev(dev, &phy_bind_list, index);
 231         if (IS_ERR(phy)) {
 232                 pr_err("unable to find transceiver\n");
 233                 goto err0;
 234         }
 235
 236         get_device(phy->dev);
 237
 238 err0:
 239         spin_unlock_irqrestore(&phy_lock, flags);
 240
 241         return phy;
 242 }
 243 EXPORT_SYMBOL(usb_get_phy_dev);
 244
 245 /**
 246  * devm_usb_get_phy_dev - find the USB PHY using device ptr and index
 247  * @dev - device that requests this phy
 248  * @index - the index of the phy
 249  *
 250  * Gets the phy using usb_get_phy_dev(), and associates a device with it using
 251  * devres. On driver detach, release function is invoked on the devres data,
 252  * then, devres data is freed.
 253  *
 254  * For use by USB host and peripheral drivers.
 255  */
 256 struct usb_phy *devm_usb_get_phy_dev(struct device *dev, u8 index)
 257 {
 258         struct usb_phy **ptr, *phy;
 259
 260         ptr = devres_alloc(devm_usb_phy_release, sizeof(*ptr), GFP_KERNEL);
 261         if (!ptr)
 262                 return NULL;
 263
 264         phy = usb_get_phy_dev(dev, index);
 265         if (!IS_ERR(phy)) {
 266                 *ptr = phy;
 267                 devres_add(dev, ptr);
 268         } else
 269                 devres_free(ptr);
 270
 271         return phy;
 272 }
 273 EXPORT_SYMBOL(devm_usb_get_phy_dev);
 274
 275 /**
 276  * devm_usb_put_phy - release the USB PHY
 277  * @dev - device that wants to release this phy
 278  * @phy - the phy returned by devm_usb_get_phy()
 279  *
 280  * destroys the devres associated with this phy and invokes usb_put_phy
 281  * to release the phy.
 282  *
 283  * For use by USB host and peripheral drivers.
 284  */
 285 void devm_usb_put_phy(struct device *dev, struct usb_phy *phy)
 286 {
 287         int r;
 288
 289         r = devres_destroy(dev, devm_usb_phy_release, devm_usb_phy_match, phy);
 290         dev_WARN_ONCE(dev, r, "couldn't find PHY resource\n");
 291 }
 292 EXPORT_SYMBOL(devm_usb_put_phy);
 293
 294 /**
 295  * usb_put_phy - release the USB PHY
 296  * @x: the phy returned by usb_get_phy()
 297  *
 298  * Releases a refcount the caller received from usb_get_phy().
 299  *
 300  * For use by USB host and peripheral drivers.
 301  */
 302 void usb_put_phy(struct usb_phy *x)
 303 {
 304         if (x)
 305                 put_device(x->dev);
 306 }
 307 EXPORT_SYMBOL(usb_put_phy);
 308
 309 /**
 310  * usb_add_phy - declare the USB PHY
 311  * @x: the USB phy to be used; or NULL
 312  * @type - the type of this PHY
 313  *
 314  * This call is exclusively for use by phy drivers, which
 315  * coordinate the activities of drivers for host and peripheral
 316  * controllers, and in some cases for VBUS current regulation.
 317  */
 318 int usb_add_phy(struct usb_phy *x, enum usb_phy_type type)
 319 {
 320         int             ret = 0;
 321         unsigned long   flags;
 322         struct usb_phy  *phy;
 323
 324         if (x->type != USB_PHY_TYPE_UNDEFINED) {
 325                 dev_err(x->dev, "not accepting initialized PHY %s\n", x->label);
 326                 return -EINVAL;
 327         }
 328
 329         spin_lock_irqsave(&phy_lock, flags);
 330
 331         list_for_each_entry(phy, &phy_list, head) {
 332                 if (phy->type == type) {
 333                         ret = -EBUSY;
 334                         dev_err(x->dev, "transceiver type %s already exists\n",
 335                                                 usb_phy_type_string(type));
 336                         goto out;
 337                 }
 338         }
 339
 340         x->type = type;
 341         list_add_tail(&x->head, &phy_list);
 342
 343 out:
 344         spin_unlock_irqrestore(&phy_lock, flags);
 345         return ret;
 346 }
 347 EXPORT_SYMBOL(usb_add_phy);
 348
 349 /**
 350  * usb_add_phy_dev - declare the USB PHY
 351  * @x: the USB phy to be used; or NULL
 352  *
 353  * This call is exclusively for use by phy drivers, which
 354  * coordinate the activities of drivers for host and peripheral
 355  * controllers, and in some cases for VBUS current regulation.
 356  */
 357 int usb_add_phy_dev(struct usb_phy *x)
 358 {
 359         struct usb_phy_bind *phy_bind;
 360         unsigned long flags;
 361
 362         if (!x->dev) {
 363                 dev_err(x->dev, "no device provided for PHY\n");
 364                 return -EINVAL;
 365         }
 366
 367         spin_lock_irqsave(&phy_lock, flags);
 368         list_for_each_entry(phy_bind, &phy_bind_list, list)
 369                 if (!(strcmp(phy_bind->phy_dev_name, dev_name(x->dev))))
 370                         phy_bind->phy = x;
 371
 372         list_add_tail(&x->head, &phy_list);
 373
 374         spin_unlock_irqrestore(&phy_lock, flags);
 375         return 0;
 376 }
 377 EXPORT_SYMBOL(usb_add_phy_dev);
 378
 379 /**
 380  * usb_remove_phy - remove the OTG PHY
 381  * @x: the USB OTG PHY to be removed;
 382  *
 383  * This reverts the effects of usb_add_phy
 384  */
 385 void usb_remove_phy(struct usb_phy *x)
 386 {
 387         unsigned long   flags;
 388         struct usb_phy_bind *phy_bind;
 389
 390         spin_lock_irqsave(&phy_lock, flags);
 391         if (x) {
 392                 list_for_each_entry(phy_bind, &phy_bind_list, list)
 393                         if (phy_bind->phy == x)
 394                                 phy_bind->phy = NULL;
 395                 list_del(&x->head);
 396         }
 397         spin_unlock_irqrestore(&phy_lock, flags);
 398 }
 399 EXPORT_SYMBOL(usb_remove_phy);
 400
 401 /**
 402  * usb_bind_phy - bind the phy and the controller that uses the phy
 403  * @dev_name: the device name of the device that will bind to the phy
 404  * @index: index to specify the port number
 405  * @phy_dev_name: the device name of the phy
 406  *
 407  * Fills the phy_bind structure with the dev_name and phy_dev_name. This will
 408  * be used when the phy driver registers the phy and when the controller
 409  * requests this phy.
 410  *
 411  * To be used by platform specific initialization code.
 412  */
 413 int __init usb_bind_phy(const char *dev_name, u8 index,
 414                                 const char *phy_dev_name)
 415 {
 416         struct usb_phy_bind *phy_bind;
 417         unsigned long flags;
 418
 419         phy_bind = kzalloc(sizeof(*phy_bind), GFP_KERNEL);
 420         if (!phy_bind) {
 421                 pr_err("phy_bind(): No memory for phy_bind");
 422                 return -ENOMEM;
 423         }
 424
 425         phy_bind->dev_name = dev_name;
 426         phy_bind->phy_dev_name = phy_dev_name;
 427         phy_bind->index = index;
 428
 429         spin_lock_irqsave(&phy_lock, flags);
 430         list_add_tail(&phy_bind->list, &phy_bind_list);
 431         spin_unlock_irqrestore(&phy_lock, flags);
 432
 433         return 0;
 434 }
 435 EXPORT_SYMBOL_GPL(usb_bind_phy);
 436
 437 const char *otg_state_string(enum usb_otg_state state)
 438 {
 439         switch (state) {
 440         case OTG_STATE_A_IDLE:
 441                 return "a_idle";
 442         case OTG_STATE_A_WAIT_VRISE:
 443                 return "a_wait_vrise";
 444         case OTG_STATE_A_WAIT_BCON:
 445                 return "a_wait_bcon";
 446         case OTG_STATE_A_HOST:
 447                 return "a_host";
 448         case OTG_STATE_A_SUSPEND:
 449                 return "a_suspend";
 450         case OTG_STATE_A_PERIPHERAL:
 451                 return "a_peripheral";
 452         case OTG_STATE_A_WAIT_VFALL:
 453                 return "a_wait_vfall";
 454         case OTG_STATE_A_VBUS_ERR:
 455                 return "a_vbus_err";
 456         case OTG_STATE_B_IDLE:
 457                 return "b_idle";
 458         case OTG_STATE_B_SRP_INIT:
 459                 return "b_srp_init";
 460         case OTG_STATE_B_PERIPHERAL:
 461                 return "b_peripheral";
 462         case OTG_STATE_B_WAIT_ACON:
 463                 return "b_wait_acon";
 464         case OTG_STATE_B_HOST:
 465                 return "b_host";
 466         default:
 467                 return "UNDEFINED";
 468         }
 469 }
 470 EXPORT_SYMBOL(otg_state_string);