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 21static LIST_HEAD(phy_list); 22static LIST_HEAD(phy_bind_list); 23static DEFINE_SPINLOCK(phy_lock); 24 25static 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 40static 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 58static 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 72static 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 79static 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 */ 95struct 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} 112EXPORT_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 */ 124struct 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 143err0: 144 spin_unlock_irqrestore(&phy_lock, flags); 145 146 return phy; 147} 148EXPORT_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 */ 165struct 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 204err1: 205 spin_unlock_irqrestore(&phy_lock, flags); 206 207err0: 208 of_node_put(node); 209 210 return phy; 211} 212EXPORT_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 */ 225struct 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 if (!IS_ERR(phy)) 236 phy = ERR_PTR(-ENODEV); 237 238 goto err0; 239 } 240 241 get_device(phy->dev); 242 243err0: 244 spin_unlock_irqrestore(&phy_lock, flags); 245 246 return phy; 247} 248EXPORT_SYMBOL_GPL(usb_get_phy_dev); 249 250/** 251 * devm_usb_get_phy_dev - find the USB PHY using device ptr and index 252 * @dev - device that requests this phy 253 * @index - the index of the phy 254 * 255 * Gets the phy using usb_get_phy_dev(), and associates a device with it using 256 * devres. On driver detach, release function is invoked on the devres data, 257 * then, devres data is freed. 258 * 259 * For use by USB host and peripheral drivers. 260 */ 261struct usb_phy *devm_usb_get_phy_dev(struct device *dev, u8 index) 262{ 263 struct usb_phy **ptr, *phy; 264 265 ptr = devres_alloc(devm_usb_phy_release, sizeof(*ptr), GFP_KERNEL); 266 if (!ptr) 267 return NULL; 268 269 phy = usb_get_phy_dev(dev, index); 270 if (!IS_ERR(phy)) { 271 *ptr = phy; 272 devres_add(dev, ptr); 273 } else 274 devres_free(ptr); 275 276 return phy; 277} 278EXPORT_SYMBOL_GPL(devm_usb_get_phy_dev); 279 280/** 281 * devm_usb_put_phy - release the USB PHY 282 * @dev - device that wants to release this phy 283 * @phy - the phy returned by devm_usb_get_phy() 284 * 285 * destroys the devres associated with this phy and invokes usb_put_phy 286 * to release the phy. 287 * 288 * For use by USB host and peripheral drivers. 289 */ 290void devm_usb_put_phy(struct device *dev, struct usb_phy *phy) 291{ 292 int r; 293 294 r = devres_destroy(dev, devm_usb_phy_release, devm_usb_phy_match, phy); 295 dev_WARN_ONCE(dev, r, "couldn't find PHY resource\n"); 296} 297EXPORT_SYMBOL_GPL(devm_usb_put_phy); 298 299/** 300 * usb_put_phy - release the USB PHY 301 * @x: the phy returned by usb_get_phy() 302 * 303 * Releases a refcount the caller received from usb_get_phy(). 304 * 305 * For use by USB host and peripheral drivers. 306 */ 307void usb_put_phy(struct usb_phy *x) 308{ 309 if (x) { 310 struct module *owner = x->dev->driver->owner; 311 312 put_device(x->dev); 313 module_put(owner); 314 } 315} 316EXPORT_SYMBOL_GPL(usb_put_phy); 317 318/** 319 * usb_add_phy - declare the USB PHY 320 * @x: the USB phy to be used; or NULL 321 * @type - the type of this PHY 322 * 323 * This call is exclusively for use by phy drivers, which 324 * coordinate the activities of drivers for host and peripheral 325 * controllers, and in some cases for VBUS current regulation. 326 */ 327int usb_add_phy(struct usb_phy *x, enum usb_phy_type type) 328{ 329 int ret = 0; 330 unsigned long flags; 331 struct usb_phy *phy; 332 333 if (x->type != USB_PHY_TYPE_UNDEFINED) { 334 dev_err(x->dev, "not accepting initialized PHY %s\n", x->label); 335 return -EINVAL; 336 } 337 338 ATOMIC_INIT_NOTIFIER_HEAD(&x->notifier); 339 340 spin_lock_irqsave(&phy_lock, flags); 341 342 list_for_each_entry(phy, &phy_list, head) { 343 if (phy->type == type) { 344 ret = -EBUSY; 345 dev_err(x->dev, "transceiver type %s already exists\n", 346 usb_phy_type_string(type)); 347 goto out; 348 } 349 } 350 351 x->type = type; 352 list_add_tail(&x->head, &phy_list); 353 354out: 355 spin_unlock_irqrestore(&phy_lock, flags); 356 return ret; 357} 358EXPORT_SYMBOL_GPL(usb_add_phy); 359 360/** 361 * usb_add_phy_dev - declare the USB PHY 362 * @x: the USB phy to be used; or NULL 363 * 364 * This call is exclusively for use by phy drivers, which 365 * coordinate the activities of drivers for host and peripheral 366 * controllers, and in some cases for VBUS current regulation. 367 */ 368int usb_add_phy_dev(struct usb_phy *x) 369{ 370 struct usb_phy_bind *phy_bind; 371 unsigned long flags; 372 373 if (!x->dev) { 374 dev_err(x->dev, "no device provided for PHY\n"); 375 return -EINVAL; 376 } 377 378 ATOMIC_INIT_NOTIFIER_HEAD(&x->notifier); 379 380 spin_lock_irqsave(&phy_lock, flags); 381 list_for_each_entry(phy_bind, &phy_bind_list, list) 382 if (!(strcmp(phy_bind->phy_dev_name, dev_name(x->dev)))) 383 phy_bind->phy = x; 384 385 list_add_tail(&x->head, &phy_list); 386 387 spin_unlock_irqrestore(&phy_lock, flags); 388 return 0; 389} 390EXPORT_SYMBOL_GPL(usb_add_phy_dev); 391 392/** 393 * usb_remove_phy - remove the OTG PHY 394 * @x: the USB OTG PHY to be removed; 395 * 396 * This reverts the effects of usb_add_phy 397 */ 398void usb_remove_phy(struct usb_phy *x) 399{ 400 unsigned long flags; 401 struct usb_phy_bind *phy_bind; 402 403 spin_lock_irqsave(&phy_lock, flags); 404 if (x) { 405 list_for_each_entry(phy_bind, &phy_bind_list, list) 406 if (phy_bind->phy == x) 407 phy_bind->phy = NULL; 408 list_del(&x->head); 409 } 410 spin_unlock_irqrestore(&phy_lock, flags); 411} 412EXPORT_SYMBOL_GPL(usb_remove_phy); 413 414/** 415 * usb_bind_phy - bind the phy and the controller that uses the phy 416 * @dev_name: the device name of the device that will bind to the phy 417 * @index: index to specify the port number 418 * @phy_dev_name: the device name of the phy 419 * 420 * Fills the phy_bind structure with the dev_name and phy_dev_name. This will 421 * be used when the phy driver registers the phy and when the controller 422 * requests this phy. 423 * 424 * To be used by platform specific initialization code. 425 */ 426int usb_bind_phy(const char *dev_name, u8 index, 427 const char *phy_dev_name) 428{ 429 struct usb_phy_bind *phy_bind; 430 unsigned long flags; 431 432 phy_bind = kzalloc(sizeof(*phy_bind), GFP_KERNEL); 433 if (!phy_bind) 434 return -ENOMEM; 435 436 phy_bind->dev_name = dev_name; 437 phy_bind->phy_dev_name = phy_dev_name; 438 phy_bind->index = index; 439 440 spin_lock_irqsave(&phy_lock, flags); 441 list_add_tail(&phy_bind->list, &phy_bind_list); 442 spin_unlock_irqrestore(&phy_lock, flags); 443 444 return 0; 445} 446EXPORT_SYMBOL_GPL(usb_bind_phy); 447