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
25struct phy_devm {
26	struct usb_phy *phy;
27	struct notifier_block *nb;
28};
29
30static struct usb_phy *__usb_find_phy(struct list_head *list,
31	enum usb_phy_type type)
32{
33	struct usb_phy  *phy = NULL;
34
35	list_for_each_entry(phy, list, head) {
36		if (phy->type != type)
37			continue;
38
39		return phy;
40	}
41
42	return ERR_PTR(-ENODEV);
43}
44
45static struct usb_phy *__usb_find_phy_dev(struct device *dev,
46	struct list_head *list, u8 index)
47{
48	struct usb_phy_bind *phy_bind = NULL;
49
50	list_for_each_entry(phy_bind, list, list) {
51		if (!(strcmp(phy_bind->dev_name, dev_name(dev))) &&
52				phy_bind->index == index) {
53			if (phy_bind->phy)
54				return phy_bind->phy;
55			else
56				return ERR_PTR(-EPROBE_DEFER);
57		}
58	}
59
60	return ERR_PTR(-ENODEV);
61}
62
63static struct usb_phy *__of_usb_find_phy(struct device_node *node)
64{
65	struct usb_phy  *phy;
66
67	if (!of_device_is_available(node))
68		return ERR_PTR(-ENODEV);
69
70	list_for_each_entry(phy, &phy_list, head) {
71		if (node != phy->dev->of_node)
72			continue;
73
74		return phy;
75	}
76
77	return ERR_PTR(-EPROBE_DEFER);
78}
79
80static void devm_usb_phy_release(struct device *dev, void *res)
81{
82	struct usb_phy *phy = *(struct usb_phy **)res;
83
84	usb_put_phy(phy);
85}
86
87static void devm_usb_phy_release2(struct device *dev, void *_res)
88{
89	struct phy_devm *res = _res;
90
91	if (res->nb)
92		usb_unregister_notifier(res->phy, res->nb);
93	usb_put_phy(res->phy);
94}
95
96static int devm_usb_phy_match(struct device *dev, void *res, void *match_data)
97{
98	struct usb_phy **phy = res;
99
100	return *phy == match_data;
101}
102
103/**
104 * devm_usb_get_phy - find the USB PHY
105 * @dev - device that requests this phy
106 * @type - the type of the phy the controller requires
107 *
108 * Gets the phy using usb_get_phy(), and associates a device with it using
109 * devres. On driver detach, release function is invoked on the devres data,
110 * then, devres data is freed.
111 *
112 * For use by USB host and peripheral drivers.
113 */
114struct usb_phy *devm_usb_get_phy(struct device *dev, enum usb_phy_type type)
115{
116	struct usb_phy **ptr, *phy;
117
118	ptr = devres_alloc(devm_usb_phy_release, sizeof(*ptr), GFP_KERNEL);
119	if (!ptr)
120		return ERR_PTR(-ENOMEM);
121
122	phy = usb_get_phy(type);
123	if (!IS_ERR(phy)) {
124		*ptr = phy;
125		devres_add(dev, ptr);
126	} else
127		devres_free(ptr);
128
129	return phy;
130}
131EXPORT_SYMBOL_GPL(devm_usb_get_phy);
132
133/**
134 * usb_get_phy - find the USB PHY
135 * @type - the type of the phy the controller requires
136 *
137 * Returns the phy driver, after getting a refcount to it; or
138 * -ENODEV if there is no such phy.  The caller is responsible for
139 * calling usb_put_phy() to release that count.
140 *
141 * For use by USB host and peripheral drivers.
142 */
143struct usb_phy *usb_get_phy(enum usb_phy_type type)
144{
145	struct usb_phy	*phy = NULL;
146	unsigned long	flags;
147
148	spin_lock_irqsave(&phy_lock, flags);
149
150	phy = __usb_find_phy(&phy_list, type);
151	if (IS_ERR(phy) || !try_module_get(phy->dev->driver->owner)) {
152		pr_debug("PHY: unable to find transceiver of type %s\n",
153			usb_phy_type_string(type));
154		if (!IS_ERR(phy))
155			phy = ERR_PTR(-ENODEV);
156
157		goto err0;
158	}
159
160	get_device(phy->dev);
161
162err0:
163	spin_unlock_irqrestore(&phy_lock, flags);
164
165	return phy;
166}
167EXPORT_SYMBOL_GPL(usb_get_phy);
168
169/**
170 * devm_usb_get_phy_by_node - find the USB PHY by device_node
171 * @dev - device that requests this phy
172 * @node - the device_node for the phy device.
173 * @nb - a notifier_block to register with the phy.
174 *
175 * Returns the phy driver associated with the given device_node,
176 * after getting a refcount to it, -ENODEV if there is no such phy or
177 * -EPROBE_DEFER if the device is not yet loaded. While at that, it
178 * also associates the device with
179 * the phy using devres. On driver detach, release function is invoked
180 * on the devres data, then, devres data is freed.
181 *
182 * For use by peripheral drivers for devices related to a phy,
183 * such as a charger.
184 */
185struct  usb_phy *devm_usb_get_phy_by_node(struct device *dev,
186					  struct device_node *node,
187					  struct notifier_block *nb)
188{
189	struct usb_phy	*phy = ERR_PTR(-ENOMEM);
190	struct phy_devm	*ptr;
191	unsigned long	flags;
192
193	ptr = devres_alloc(devm_usb_phy_release2, sizeof(*ptr), GFP_KERNEL);
194	if (!ptr) {
195		dev_dbg(dev, "failed to allocate memory for devres\n");
196		goto err0;
197	}
198
199	spin_lock_irqsave(&phy_lock, flags);
200
201	phy = __of_usb_find_phy(node);
202	if (IS_ERR(phy)) {
203		devres_free(ptr);
204		goto err1;
205	}
206
207	if (!try_module_get(phy->dev->driver->owner)) {
208		phy = ERR_PTR(-ENODEV);
209		devres_free(ptr);
210		goto err1;
211	}
212	if (nb)
213		usb_register_notifier(phy, nb);
214	ptr->phy = phy;
215	ptr->nb = nb;
216	devres_add(dev, ptr);
217
218	get_device(phy->dev);
219
220err1:
221	spin_unlock_irqrestore(&phy_lock, flags);
222
223err0:
224
225	return phy;
226}
227EXPORT_SYMBOL_GPL(devm_usb_get_phy_by_node);
228
229/**
230 * devm_usb_get_phy_by_phandle - find the USB PHY by phandle
231 * @dev - device that requests this phy
232 * @phandle - name of the property holding the phy phandle value
233 * @index - the index of the phy
234 *
235 * Returns the phy driver associated with the given phandle value,
236 * after getting a refcount to it, -ENODEV if there is no such phy or
237 * -EPROBE_DEFER if there is a phandle to the phy, but the device is
238 * not yet loaded. While at that, it also associates the device with
239 * the phy using devres. On driver detach, release function is invoked
240 * on the devres data, then, devres data is freed.
241 *
242 * For use by USB host and peripheral drivers.
243 */
244struct usb_phy *devm_usb_get_phy_by_phandle(struct device *dev,
245	const char *phandle, u8 index)
246{
247	struct device_node *node;
248	struct usb_phy	*phy;
249
250	if (!dev->of_node) {
251		dev_dbg(dev, "device does not have a device node entry\n");
252		return ERR_PTR(-EINVAL);
253	}
254
255	node = of_parse_phandle(dev->of_node, phandle, index);
256	if (!node) {
257		dev_dbg(dev, "failed to get %s phandle in %s node\n", phandle,
258			dev->of_node->full_name);
259		return ERR_PTR(-ENODEV);
260	}
261	phy = devm_usb_get_phy_by_node(dev, node, NULL);
262	of_node_put(node);
263	return phy;
264}
265EXPORT_SYMBOL_GPL(devm_usb_get_phy_by_phandle);
266
267/**
268 * usb_get_phy_dev - find the USB PHY
269 * @dev - device that requests this phy
270 * @index - the index of the phy
271 *
272 * Returns the phy driver, after getting a refcount to it; or
273 * -ENODEV if there is no such phy.  The caller is responsible for
274 * calling usb_put_phy() to release that count.
275 *
276 * For use by USB host and peripheral drivers.
277 */
278struct usb_phy *usb_get_phy_dev(struct device *dev, u8 index)
279{
280	struct usb_phy	*phy = NULL;
281	unsigned long	flags;
282
283	spin_lock_irqsave(&phy_lock, flags);
284
285	phy = __usb_find_phy_dev(dev, &phy_bind_list, index);
286	if (IS_ERR(phy) || !try_module_get(phy->dev->driver->owner)) {
287		dev_dbg(dev, "unable to find transceiver\n");
288		if (!IS_ERR(phy))
289			phy = ERR_PTR(-ENODEV);
290
291		goto err0;
292	}
293
294	get_device(phy->dev);
295
296err0:
297	spin_unlock_irqrestore(&phy_lock, flags);
298
299	return phy;
300}
301EXPORT_SYMBOL_GPL(usb_get_phy_dev);
302
303/**
304 * devm_usb_get_phy_dev - find the USB PHY using device ptr and index
305 * @dev - device that requests this phy
306 * @index - the index of the phy
307 *
308 * Gets the phy using usb_get_phy_dev(), and associates a device with it using
309 * devres. On driver detach, release function is invoked on the devres data,
310 * then, devres data is freed.
311 *
312 * For use by USB host and peripheral drivers.
313 */
314struct usb_phy *devm_usb_get_phy_dev(struct device *dev, u8 index)
315{
316	struct usb_phy **ptr, *phy;
317
318	ptr = devres_alloc(devm_usb_phy_release, sizeof(*ptr), GFP_KERNEL);
319	if (!ptr)
320		return NULL;
321
322	phy = usb_get_phy_dev(dev, index);
323	if (!IS_ERR(phy)) {
324		*ptr = phy;
325		devres_add(dev, ptr);
326	} else
327		devres_free(ptr);
328
329	return phy;
330}
331EXPORT_SYMBOL_GPL(devm_usb_get_phy_dev);
332
333/**
334 * devm_usb_put_phy - release the USB PHY
335 * @dev - device that wants to release this phy
336 * @phy - the phy returned by devm_usb_get_phy()
337 *
338 * destroys the devres associated with this phy and invokes usb_put_phy
339 * to release the phy.
340 *
341 * For use by USB host and peripheral drivers.
342 */
343void devm_usb_put_phy(struct device *dev, struct usb_phy *phy)
344{
345	int r;
346
347	r = devres_destroy(dev, devm_usb_phy_release, devm_usb_phy_match, phy);
348	dev_WARN_ONCE(dev, r, "couldn't find PHY resource\n");
349}
350EXPORT_SYMBOL_GPL(devm_usb_put_phy);
351
352/**
353 * usb_put_phy - release the USB PHY
354 * @x: the phy returned by usb_get_phy()
355 *
356 * Releases a refcount the caller received from usb_get_phy().
357 *
358 * For use by USB host and peripheral drivers.
359 */
360void usb_put_phy(struct usb_phy *x)
361{
362	if (x) {
363		struct module *owner = x->dev->driver->owner;
364
365		put_device(x->dev);
366		module_put(owner);
367	}
368}
369EXPORT_SYMBOL_GPL(usb_put_phy);
370
371/**
372 * usb_add_phy - declare the USB PHY
373 * @x: the USB phy to be used; or NULL
374 * @type - the type of this PHY
375 *
376 * This call is exclusively for use by phy drivers, which
377 * coordinate the activities of drivers for host and peripheral
378 * controllers, and in some cases for VBUS current regulation.
379 */
380int usb_add_phy(struct usb_phy *x, enum usb_phy_type type)
381{
382	int		ret = 0;
383	unsigned long	flags;
384	struct usb_phy	*phy;
385
386	if (x->type != USB_PHY_TYPE_UNDEFINED) {
387		dev_err(x->dev, "not accepting initialized PHY %s\n", x->label);
388		return -EINVAL;
389	}
390
391	ATOMIC_INIT_NOTIFIER_HEAD(&x->notifier);
392
393	spin_lock_irqsave(&phy_lock, flags);
394
395	list_for_each_entry(phy, &phy_list, head) {
396		if (phy->type == type) {
397			ret = -EBUSY;
398			dev_err(x->dev, "transceiver type %s already exists\n",
399						usb_phy_type_string(type));
400			goto out;
401		}
402	}
403
404	x->type = type;
405	list_add_tail(&x->head, &phy_list);
406
407out:
408	spin_unlock_irqrestore(&phy_lock, flags);
409	return ret;
410}
411EXPORT_SYMBOL_GPL(usb_add_phy);
412
413/**
414 * usb_add_phy_dev - declare the USB PHY
415 * @x: the USB phy to be used; or NULL
416 *
417 * This call is exclusively for use by phy drivers, which
418 * coordinate the activities of drivers for host and peripheral
419 * controllers, and in some cases for VBUS current regulation.
420 */
421int usb_add_phy_dev(struct usb_phy *x)
422{
423	struct usb_phy_bind *phy_bind;
424	unsigned long flags;
425
426	if (!x->dev) {
427		dev_err(x->dev, "no device provided for PHY\n");
428		return -EINVAL;
429	}
430
431	ATOMIC_INIT_NOTIFIER_HEAD(&x->notifier);
432
433	spin_lock_irqsave(&phy_lock, flags);
434	list_for_each_entry(phy_bind, &phy_bind_list, list)
435		if (!(strcmp(phy_bind->phy_dev_name, dev_name(x->dev))))
436			phy_bind->phy = x;
437
438	list_add_tail(&x->head, &phy_list);
439
440	spin_unlock_irqrestore(&phy_lock, flags);
441	return 0;
442}
443EXPORT_SYMBOL_GPL(usb_add_phy_dev);
444
445/**
446 * usb_remove_phy - remove the OTG PHY
447 * @x: the USB OTG PHY to be removed;
448 *
449 * This reverts the effects of usb_add_phy
450 */
451void usb_remove_phy(struct usb_phy *x)
452{
453	unsigned long	flags;
454	struct usb_phy_bind *phy_bind;
455
456	spin_lock_irqsave(&phy_lock, flags);
457	if (x) {
458		list_for_each_entry(phy_bind, &phy_bind_list, list)
459			if (phy_bind->phy == x)
460				phy_bind->phy = NULL;
461		list_del(&x->head);
462	}
463	spin_unlock_irqrestore(&phy_lock, flags);
464}
465EXPORT_SYMBOL_GPL(usb_remove_phy);
466
467/**
468 * usb_bind_phy - bind the phy and the controller that uses the phy
469 * @dev_name: the device name of the device that will bind to the phy
470 * @index: index to specify the port number
471 * @phy_dev_name: the device name of the phy
472 *
473 * Fills the phy_bind structure with the dev_name and phy_dev_name. This will
474 * be used when the phy driver registers the phy and when the controller
475 * requests this phy.
476 *
477 * To be used by platform specific initialization code.
478 */
479int usb_bind_phy(const char *dev_name, u8 index,
480				const char *phy_dev_name)
481{
482	struct usb_phy_bind *phy_bind;
483	unsigned long flags;
484
485	phy_bind = kzalloc(sizeof(*phy_bind), GFP_KERNEL);
486	if (!phy_bind)
487		return -ENOMEM;
488
489	phy_bind->dev_name = dev_name;
490	phy_bind->phy_dev_name = phy_dev_name;
491	phy_bind->index = index;
492
493	spin_lock_irqsave(&phy_lock, flags);
494	list_add_tail(&phy_bind->list, &phy_bind_list);
495	spin_unlock_irqrestore(&phy_lock, flags);
496
497	return 0;
498}
499EXPORT_SYMBOL_GPL(usb_bind_phy);
500
501/**
502 * usb_phy_set_event - set event to phy event
503 * @x: the phy returned by usb_get_phy();
504 *
505 * This sets event to phy event
506 */
507void usb_phy_set_event(struct usb_phy *x, unsigned long event)
508{
509	x->last_event = event;
510}
511EXPORT_SYMBOL_GPL(usb_phy_set_event);
512