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		goto err0;
236	}
237
238	get_device(phy->dev);
239
240err0:
241	spin_unlock_irqrestore(&phy_lock, flags);
242
243	return phy;
244}
245EXPORT_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 */
258struct 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}
275EXPORT_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 */
287void 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}
294EXPORT_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 */
304void 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}
313EXPORT_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 */
324int 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
351out:
352	spin_unlock_irqrestore(&phy_lock, flags);
353	return ret;
354}
355EXPORT_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 */
365int 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}
387EXPORT_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 */
395void 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}
409EXPORT_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 */
423int 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}
443EXPORT_SYMBOL_GPL(usb_bind_phy);