summaryrefslogtreecommitdiff
path: root/drivers/usb/phy/phy.c
blob: e6bf801a339a477c7d0abc0841ffd170d95ae60a (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
/*
 * phy.c -- USB phy handling
 *
 * Copyright (C) 2004-2013 Texas Instruments
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 */
#include <linux/kernel.h>
#include <linux/export.h>
#include <linux/err.h>
#include <linux/device.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/of.h>

#include <linux/usb/phy.h>

static LIST_HEAD(phy_list);
static LIST_HEAD(phy_bind_list);
static DEFINE_SPINLOCK(phy_lock);

static struct usb_phy *__usb_find_phy(struct list_head *list,
	enum usb_phy_type type)
{
	struct usb_phy  *phy = NULL;

	list_for_each_entry(phy, list, head) {
		if (phy->type != type)
			continue;

		return phy;
	}

	return ERR_PTR(-ENODEV);
}

static struct usb_phy *__usb_find_phy_dev(struct device *dev,
	struct list_head *list, u8 index)
{
	struct usb_phy_bind *phy_bind = NULL;

	list_for_each_entry(phy_bind, list, list) {
		if (!(strcmp(phy_bind->dev_name, dev_name(dev))) &&
				phy_bind->index == index) {
			if (phy_bind->phy)
				return phy_bind->phy;
			else
				return ERR_PTR(-EPROBE_DEFER);
		}
	}

	return ERR_PTR(-ENODEV);
}

static struct usb_phy *__of_usb_find_phy(struct device_node *node)
{
	struct usb_phy  *phy;

	list_for_each_entry(phy, &phy_list, head) {
		if (node != phy->dev->of_node)
			continue;

		return phy;
	}

	return ERR_PTR(-ENODEV);
}

static void devm_usb_phy_release(struct device *dev, void *res)
{
	struct usb_phy *phy = *(struct usb_phy **)res;

	usb_put_phy(phy);
}

static int devm_usb_phy_match(struct device *dev, void *res, void *match_data)
{
	return res == match_data;
}

/**
 * devm_usb_get_phy - find the USB PHY
 * @dev - device that requests this phy
 * @type - the type of the phy the controller requires
 *
 * Gets the phy using usb_get_phy(), and associates a device with it using
 * devres. On driver detach, release function is invoked on the devres data,
 * then, devres data is freed.
 *
 * For use by USB host and peripheral drivers.
 */
struct usb_phy *devm_usb_get_phy(struct device *dev, enum usb_phy_type type)
{
	struct usb_phy **ptr, *phy;

	ptr = devres_alloc(devm_usb_phy_release, sizeof(*ptr), GFP_KERNEL);
	if (!ptr)
		return ERR_PTR(-ENOMEM);

	phy = usb_get_phy(type);
	if (!IS_ERR(phy)) {
		*ptr = phy;
		devres_add(dev, ptr);
	} else
		devres_free(ptr);

	return phy;
}
EXPORT_SYMBOL_GPL(devm_usb_get_phy);

/**
 * usb_get_phy - find the USB PHY
 * @type - the type of the phy the controller requires
 *
 * Returns the phy driver, after getting a refcount to it; or
 * -ENODEV if there is no such phy.  The caller is responsible for
 * calling usb_put_phy() to release that count.
 *
 * For use by USB host and peripheral drivers.
 */
struct usb_phy *usb_get_phy(enum usb_phy_type type)
{
	struct usb_phy	*phy = NULL;
	unsigned long	flags;

	spin_lock_irqsave(&phy_lock, flags);

	phy = __usb_find_phy(&phy_list, type);
	if (IS_ERR(phy) || !try_module_get(phy->dev->driver->owner)) {
		pr_debug("PHY: unable to find transceiver of type %s\n",
			usb_phy_type_string(type));
		if (!IS_ERR(phy))
			phy = ERR_PTR(-ENODEV);

		goto err0;
	}

	get_device(phy->dev);

err0:
	spin_unlock_irqrestore(&phy_lock, flags);

	return phy;
}
EXPORT_SYMBOL_GPL(usb_get_phy);

/**
 * devm_usb_get_phy_by_phandle - find the USB PHY by phandle
 * @dev - device that requests this phy
 * @phandle - name of the property holding the phy phandle value
 * @index - the index of the phy
 *
 * Returns the phy driver associated with the given phandle value,
 * after getting a refcount to it, -ENODEV if there is no such phy or
 * -EPROBE_DEFER if there is a phandle to the phy, but the device is
 * not yet loaded. While at that, it also associates the device with
 * the phy using devres. On driver detach, release function is invoked
 * on the devres data, then, devres data is freed.
 *
 * For use by USB host and peripheral drivers.
 */
struct usb_phy *devm_usb_get_phy_by_phandle(struct device *dev,
	const char *phandle, u8 index)
{
	struct usb_phy	*phy = ERR_PTR(-ENOMEM), **ptr;
	unsigned long	flags;
	struct device_node *node;

	if (!dev->of_node) {
		dev_dbg(dev, "device does not have a device node entry\n");
		return ERR_PTR(-EINVAL);
	}

	node = of_parse_phandle(dev->of_node, phandle, index);
	if (!node) {
		dev_dbg(dev, "failed to get %s phandle in %s node\n", phandle,
			dev->of_node->full_name);
		return ERR_PTR(-ENODEV);
	}

	ptr = devres_alloc(devm_usb_phy_release, sizeof(*ptr), GFP_KERNEL);
	if (!ptr) {
		dev_dbg(dev, "failed to allocate memory for devres\n");
		goto err0;
	}

	spin_lock_irqsave(&phy_lock, flags);

	phy = __of_usb_find_phy(node);
	if (IS_ERR(phy) || !try_module_get(phy->dev->driver->owner)) {
		if (!IS_ERR(phy))
			phy = ERR_PTR(-EPROBE_DEFER);

		devres_free(ptr);
		goto err1;
	}

	*ptr = phy;
	devres_add(dev, ptr);

	get_device(phy->dev);

err1:
	spin_unlock_irqrestore(&phy_lock, flags);

err0:
	of_node_put(node);

	return phy;
}
EXPORT_SYMBOL_GPL(devm_usb_get_phy_by_phandle);

/**
 * usb_get_phy_dev - find the USB PHY
 * @dev - device that requests this phy
 * @index - the index of the phy
 *
 * Returns the phy driver, after getting a refcount to it; or
 * -ENODEV if there is no such phy.  The caller is responsible for
 * calling usb_put_phy() to release that count.
 *
 * For use by USB host and peripheral drivers.
 */
struct usb_phy *usb_get_phy_dev(struct device *dev, u8 index)
{
	struct usb_phy	*phy = NULL;
	unsigned long	flags;

	spin_lock_irqsave(&phy_lock, flags);

	phy = __usb_find_phy_dev(dev, &phy_bind_list, index);
	if (IS_ERR(phy) || !try_module_get(phy->dev->driver->owner)) {
		dev_dbg(dev, "unable to find transceiver\n");
		if (!IS_ERR(phy))
			phy = ERR_PTR(-ENODEV);

		goto err0;
	}

	get_device(phy->dev);

err0:
	spin_unlock_irqrestore(&phy_lock, flags);

	return phy;
}
EXPORT_SYMBOL_GPL(usb_get_phy_dev);

/**
 * devm_usb_get_phy_dev - find the USB PHY using device ptr and index
 * @dev - device that requests this phy
 * @index - the index of the phy
 *
 * Gets the phy using usb_get_phy_dev(), and associates a device with it using
 * devres. On driver detach, release function is invoked on the devres data,
 * then, devres data is freed.
 *
 * For use by USB host and peripheral drivers.
 */
struct usb_phy *devm_usb_get_phy_dev(struct device *dev, u8 index)
{
	struct usb_phy **ptr, *phy;

	ptr = devres_alloc(devm_usb_phy_release, sizeof(*ptr), GFP_KERNEL);
	if (!ptr)
		return NULL;

	phy = usb_get_phy_dev(dev, index);
	if (!IS_ERR(phy)) {
		*ptr = phy;
		devres_add(dev, ptr);
	} else
		devres_free(ptr);

	return phy;
}
EXPORT_SYMBOL_GPL(devm_usb_get_phy_dev);

/**
 * devm_usb_put_phy - release the USB PHY
 * @dev - device that wants to release this phy
 * @phy - the phy returned by devm_usb_get_phy()
 *
 * destroys the devres associated with this phy and invokes usb_put_phy
 * to release the phy.
 *
 * For use by USB host and peripheral drivers.
 */
void devm_usb_put_phy(struct device *dev, struct usb_phy *phy)
{
	int r;

	r = devres_destroy(dev, devm_usb_phy_release, devm_usb_phy_match, phy);
	dev_WARN_ONCE(dev, r, "couldn't find PHY resource\n");
}
EXPORT_SYMBOL_GPL(devm_usb_put_phy);

/**
 * usb_put_phy - release the USB PHY
 * @x: the phy returned by usb_get_phy()
 *
 * Releases a refcount the caller received from usb_get_phy().
 *
 * For use by USB host and peripheral drivers.
 */
void usb_put_phy(struct usb_phy *x)
{
	if (x) {
		struct module *owner = x->dev->driver->owner;

		put_device(x->dev);
		module_put(owner);
	}
}
EXPORT_SYMBOL_GPL(usb_put_phy);

/**
 * usb_add_phy - declare the USB PHY
 * @x: the USB phy to be used; or NULL
 * @type - the type of this PHY
 *
 * This call is exclusively for use by phy drivers, which
 * coordinate the activities of drivers for host and peripheral
 * controllers, and in some cases for VBUS current regulation.
 */
int usb_add_phy(struct usb_phy *x, enum usb_phy_type type)
{
	int		ret = 0;
	unsigned long	flags;
	struct usb_phy	*phy;

	if (x->type != USB_PHY_TYPE_UNDEFINED) {
		dev_err(x->dev, "not accepting initialized PHY %s\n", x->label);
		return -EINVAL;
	}

	ATOMIC_INIT_NOTIFIER_HEAD(&x->notifier);

	spin_lock_irqsave(&phy_lock, flags);

	list_for_each_entry(phy, &phy_list, head) {
		if (phy->type == type) {
			ret = -EBUSY;
			dev_err(x->dev, "transceiver type %s already exists\n",
						usb_phy_type_string(type));
			goto out;
		}
	}

	x->type = type;
	list_add_tail(&x->head, &phy_list);

out:
	spin_unlock_irqrestore(&phy_lock, flags);
	return ret;
}
EXPORT_SYMBOL_GPL(usb_add_phy);

/**
 * usb_add_phy_dev - declare the USB PHY
 * @x: the USB phy to be used; or NULL
 *
 * This call is exclusively for use by phy drivers, which
 * coordinate the activities of drivers for host and peripheral
 * controllers, and in some cases for VBUS current regulation.
 */
int usb_add_phy_dev(struct usb_phy *x)
{
	struct usb_phy_bind *phy_bind;
	unsigned long flags;

	if (!x->dev) {
		dev_err(x->dev, "no device provided for PHY\n");
		return -EINVAL;
	}

	ATOMIC_INIT_NOTIFIER_HEAD(&x->notifier);

	spin_lock_irqsave(&phy_lock, flags);
	list_for_each_entry(phy_bind, &phy_bind_list, list)
		if (!(strcmp(phy_bind->phy_dev_name, dev_name(x->dev))))
			phy_bind->phy = x;

	list_add_tail(&x->head, &phy_list);

	spin_unlock_irqrestore(&phy_lock, flags);
	return 0;
}
EXPORT_SYMBOL_GPL(usb_add_phy_dev);

/**
 * usb_remove_phy - remove the OTG PHY
 * @x: the USB OTG PHY to be removed;
 *
 * This reverts the effects of usb_add_phy
 */
void usb_remove_phy(struct usb_phy *x)
{
	unsigned long	flags;
	struct usb_phy_bind *phy_bind;

	spin_lock_irqsave(&phy_lock, flags);
	if (x) {
		list_for_each_entry(phy_bind, &phy_bind_list, list)
			if (phy_bind->phy == x)
				phy_bind->phy = NULL;
		list_del(&x->head);
	}
	spin_unlock_irqrestore(&phy_lock, flags);
}
EXPORT_SYMBOL_GPL(usb_remove_phy);

/**
 * usb_bind_phy - bind the phy and the controller that uses the phy
 * @dev_name: the device name of the device that will bind to the phy
 * @index: index to specify the port number
 * @phy_dev_name: the device name of the phy
 *
 * Fills the phy_bind structure with the dev_name and phy_dev_name. This will
 * be used when the phy driver registers the phy and when the controller
 * requests this phy.
 *
 * To be used by platform specific initialization code.
 */
int usb_bind_phy(const char *dev_name, u8 index,
				const char *phy_dev_name)
{
	struct usb_phy_bind *phy_bind;
	unsigned long flags;

	phy_bind = kzalloc(sizeof(*phy_bind), GFP_KERNEL);
	if (!phy_bind)
		return -ENOMEM;

	phy_bind->dev_name = dev_name;
	phy_bind->phy_dev_name = phy_dev_name;
	phy_bind->index = index;

	spin_lock_irqsave(&phy_lock, flags);
	list_add_tail(&phy_bind->list, &phy_bind_list);
	spin_unlock_irqrestore(&phy_lock, flags);

	return 0;
}
EXPORT_SYMBOL_GPL(usb_bind_phy);