[go: nahoru, domu]
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