aboutsummaryrefslogtreecommitdiffstats
path: root/include/linux/extcon.h
blob: cdd4014776566bbe395bd635ef8360b2c073cedc (plain) (blame)
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
/*
 *  External connector (extcon) class driver
 *
 * Copyright (C) 2012 Samsung Electronics
 * Author: Donggeun Kim <dg77.kim@samsung.com>
 * Author: MyungJoo Ham <myungjoo.ham@samsung.com>
 *
 * based on switch class driver
 * Copyright (C) 2008 Google, Inc.
 * Author: Mike Lockwood <lockwood@android.com>
 *
 * This software is licensed under the terms of the GNU General Public
 * License version 2, as published by the Free Software Foundation, and
 * may be copied, distributed, and modified under those terms.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
*/

#ifndef __LINUX_EXTCON_H__
#define __LINUX_EXTCON_H__

#include <linux/notifier.h>

#define SUPPORTED_CABLE_MAX	32
#define CABLE_NAME_MAX		30

/*
 * The standard cable name is to help support general notifier
 * and notifee device drivers to share the common names.
 * Please use standard cable names unless your notifier device has
 * a very unique and abnormal cable or
 * the cable type is supposed to be used with only one unique
 * pair of notifier/notifee devices.
 *
 * Please add any other "standard" cables used with extcon dev.
 *
 * You may add a dot and number to specify version or specification
 * of the specific cable if it is required. (e.g., "Fast-charger.18"
 * and "Fast-charger.10" for 1.8A and 1.0A chargers)
 * However, the notifee and notifier should be able to handle such
 * string and if the notifee can negotiate the protocol or idenify,
 * you don't need such convention. This convention is helpful when
 * notifier can distinguish but notifiee cannot.
 */
enum extcon_cable_name {
	EXTCON_USB = 0,
	EXTCON_USB_HOST,
	EXTCON_TA, /* Travel Adaptor */
	EXTCON_FAST_CHARGER,
	EXTCON_SLOW_CHARGER,
	EXTCON_CHARGE_DOWNSTREAM, /* Charging an external device */
	EXTCON_HDMI,
	EXTCON_MHL,
	EXTCON_DVI,
	EXTCON_VGA,
	EXTCON_DOCK,
	EXTCON_LINE_IN,
	EXTCON_LINE_OUT,
	EXTCON_MIC_IN,
	EXTCON_HEADPHONE_OUT,
	EXTCON_SPDIF_IN,
	EXTCON_SPDIF_OUT,
	EXTCON_VIDEO_IN,
	EXTCON_VIDEO_OUT,
	EXTCON_MECHANICAL,
};
extern const char *extcon_cable_name[];

struct extcon_cable;

/**
 * struct extcon_dev - An extcon device represents one external connector.
 * @name	The name of this extcon device. Parent device name is used
 *		if NULL.
 * @supported_cable	Array of supported cable name ending with NULL.
 *			If supported_cable is NULL, cable name related APIs
 *			are disabled.
 * @mutually_exclusive	Array of mutually exclusive set of cables that cannot
 *			be attached simultaneously. The array should be
 *			ending with NULL or be NULL (no mutually exclusive
 *			cables). For example, if it is { 0x7, 0x30, 0}, then,
 *			{0, 1}, {0, 1, 2}, {0, 2}, {1, 2}, or {4, 5} cannot
 *			be attached simulataneously. {0x7, 0} is equivalent to
 *			{0x3, 0x6, 0x5, 0}. If it is {0xFFFFFFFF, 0}, there
 *			can be no simultaneous connections.
 * @print_name	An optional callback to override the method to print the
 *		name of the extcon device.
 * @print_state	An optional callback to override the method to print the
 *		status of the extcon device.
 * @dev		Device of this extcon. Do not provide at register-time.
 * @state	Attach/detach state of this extcon. Do not provide at
 *		register-time
 * @nh	Notifier for the state change events from this extcon
 * @entry	To support list of extcon devices so that uses can search
 *		for extcon devices based on the extcon name.
 * @lock
 * @max_supported	Internal value to store the number of cables.
 * @extcon_dev_type	Device_type struct to provide attribute_groups
 *			customized for each extcon device.
 * @cables	Sysfs subdirectories. Each represents one cable.
 *
 * In most cases, users only need to provide "User initializing data" of
 * this struct when registering an extcon. In some exceptional cases,
 * optional callbacks may be needed. However, the values in "internal data"
 * are overwritten by register function.
 */
struct extcon_dev {
	/* --- Optional user initializing data --- */
	const char	*name;
	const char **supported_cable;
	const u32	*mutually_exclusive;

	/* --- Optional callbacks to override class functions --- */
	ssize_t	(*print_name)(struct extcon_dev *edev, char *buf);
	ssize_t	(*print_state)(struct extcon_dev *edev, char *buf);

	/* --- Internal data. Please do not set. --- */
	struct device	*dev;
	u32		state;
	struct raw_notifier_head nh;
	struct list_head entry;
	spinlock_t lock; /* could be called by irq handler */
	int max_supported;

	/* /sys/class/extcon/.../cable.n/... */
	struct device_type extcon_dev_type;
	struct extcon_cable *cables;
	/* /sys/class/extcon/.../mutually_exclusive/... */
	struct attribute_group attr_g_muex;
	struct attribute **attrs_muex;
	struct device_attribute *d_attrs_muex;
};

/**
 * struct extcon_cable	- An internal data for each cable of extcon device.
 * @edev	The extcon device
 * @cable_index	Index of this cable in the edev
 * @attr_g	Attribute group for the cable
 * @attr_name	"name" sysfs entry
 * @attr_state	"state" sysfs entry
 * @attrs	Array pointing to attr_name and attr_state for attr_g
 */
struct extcon_cable {
	struct extcon_dev *edev;
	int cable_index;

	struct attribute_group attr_g;
	struct device_attribute attr_name;
	struct device_attribute attr_state;

	struct attribute *attrs[3]; /* to be fed to attr_g.attrs */
};

/**
 * struct extcon_specific_cable_nb - An internal data for
 *				extcon_register_interest().
 * @internal_nb	a notifier block bridging extcon notifier and cable notifier.
 * @user_nb	user provided notifier block for events from a specific cable.
 * @cable_index	the target cable.
 * @edev	the target extcon device.
 * @previous_value	the saved previous event value.
 */
struct extcon_specific_cable_nb {
	struct notifier_block internal_nb;
	struct notifier_block *user_nb;
	int cable_index;
	struct extcon_dev *edev;
	unsigned long previous_value;
};

#if IS_ENABLED(CONFIG_EXTCON)

/*
 * Following APIs are for notifiers or configurations.
 * Notifiers are the external port and connection devices.
 */
extern int extcon_dev_register(struct extcon_dev *edev, struct device *dev);
extern void extcon_dev_unregister(struct extcon_dev *edev);
extern struct extcon_dev *extcon_get_extcon_dev(const char *extcon_name);

/*
 * get/set/update_state access the 32b encoded state value, which represents
 * states of all possible cables of the multistate port. For example, if one
 * calls extcon_set_state(edev, 0x7), it may mean that all the three cables
 * are attached to the port.
 */
static inline u32 extcon_get_state(struct extcon_dev *edev)
{
	return edev->state;
}

extern int extcon_set_state(struct extcon_dev *edev, u32 state);
extern int extcon_update_state(struct extcon_dev *edev, u32 mask, u32 state);

/*
 * get/set_cable_state access each bit of the 32b encoded state value.
 * They are used to access the status of each cable based on the cable_name
 * or cable_index, which is retrived by extcon_find_cable_index
 */
extern int extcon_find_cable_index(struct extcon_dev *sdev,
				   const char *cable_name);
extern int extcon_get_cable_state_(struct extcon_dev *edev, int cable_index);
extern int extcon_set_cable_state_(struct extcon_dev *edev, int cable_index,
				   bool cable_state);

extern int extcon_get_cable_state(struct extcon_dev *edev,
				  const char *cable_name);
extern int extcon_set_cable_state(struct extcon_dev *edev,
				  const char *cable_name, bool cable_state);

/*
 * Following APIs are for notifiees (those who want to be notified)
 * to register a callback for events from a specific cable of the extcon.
 * Notifiees are the connected device drivers wanting to get notified by
 * a specific external port of a connection device.
 */
extern int extcon_register_interest(struct extcon_specific_cable_nb *obj,
				    const char *extcon_name,
				    const char *cable_name,
				    struct notifier_block *nb);
extern int extcon_unregister_interest(struct extcon_specific_cable_nb *nb);

/*
 * Following APIs are to monitor every action of a notifier.
 * Registerer gets notified for every external port of a connection device.
 * Probably this could be used to debug an action of notifier; however,
 * we do not recommend to use this at normal 'notifiee' device drivers who
 * want to be notified by a specific external port of the notifier.
 */
extern int extcon_register_notifier(struct extcon_dev *edev,
				    struct notifier_block *nb);
extern int extcon_unregister_notifier(struct extcon_dev *edev,
				      struct notifier_block *nb);
#else /* CONFIG_EXTCON */
static inline int extcon_dev_register(struct extcon_dev *edev,
				      struct device *dev)
{
	return 0;
}

static inline void extcon_dev_unregister(struct extcon_dev *edev) { }

static inline u32 extcon_get_state(struct extcon_dev *edev)
{
	return 0;
}

static inline int extcon_set_state(struct extcon_dev *edev, u32 state)
{
	return 0;
}

static inline int extcon_update_state(struct extcon_dev *edev, u32 mask,
				       u32 state)
{
	return 0;
}

static inline int extcon_find_cable_index(struct extcon_dev *edev,
					  const char *cable_name)
{
	return 0;
}

static inline int extcon_get_cable_state_(struct extcon_dev *edev,
					  int cable_index)
{
	return 0;
}

static inline int extcon_set_cable_state_(struct extcon_dev *edev,
					  int cable_index, bool cable_state)
{
	return 0;
}

static inline int extcon_get_cable_state(struct extcon_dev *edev,
			const char *cable_name)
{
	return 0;
}

static inline int extcon_set_cable_state(struct extcon_dev *edev,
			const char *cable_name, int state)
{
	return 0;
}

static inline struct extcon_dev *extcon_get_extcon_dev(const char *extcon_name)
{
	return NULL;
}

static inline int extcon_register_notifier(struct extcon_dev *edev,
					   struct notifier_block *nb)
{
	return 0;
}

static inline int extcon_unregister_notifier(struct extcon_dev *edev,
					     struct notifier_block *nb)
{
	return 0;
}

static inline int extcon_register_interest(struct extcon_specific_cable_nb *obj,
					   const char *extcon_name,
					   const char *cable_name,
					   struct notifier_block *nb)
{
	return 0;
}

static inline int extcon_unregister_interest(struct extcon_specific_cable_nb
						    *obj)
{
	return 0;
}
#endif /* CONFIG_EXTCON */
#endif /* __LINUX_EXTCON_H__ */