xref: /linux-6.15/include/linux/extcon.h (revision 87be28aa)
1 /*
2  *  External connector (extcon) class driver
3  *
4  * Copyright (C) 2015 Samsung Electronics
5  * Author: Chanwoo Choi <[email protected]>
6  *
7  * Copyright (C) 2012 Samsung Electronics
8  * Author: Donggeun Kim <[email protected]>
9  * Author: MyungJoo Ham <[email protected]>
10  *
11  * based on switch class driver
12  * Copyright (C) 2008 Google, Inc.
13  * Author: Mike Lockwood <[email protected]>
14  *
15  * This software is licensed under the terms of the GNU General Public
16  * License version 2, as published by the Free Software Foundation, and
17  * may be copied, distributed, and modified under those terms.
18  *
19  * This program is distributed in the hope that it will be useful,
20  * but WITHOUT ANY WARRANTY; without even the implied warranty of
21  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
22  * GNU General Public License for more details.
23  *
24 */
25 
26 #ifndef __LINUX_EXTCON_H__
27 #define __LINUX_EXTCON_H__
28 
29 #include <linux/device.h>
30 #include <linux/notifier.h>
31 #include <linux/sysfs.h>
32 
33 /*
34  * Define the unique id of supported external connectors
35  */
36 #define EXTCON_NONE			0
37 
38 #define EXTCON_USB			1	/* USB connector */
39 #define EXTCON_USB_HOST			2
40 
41 #define EXTCON_TA			3	/* Charger connector */
42 #define EXTCON_FAST_CHARGER		4
43 #define EXTCON_SLOW_CHARGER		5
44 #define EXTCON_CHARGE_DOWNSTREAM	6
45 
46 #define EXTCON_LINE_IN			7	/* Audio/Video connector */
47 #define EXTCON_LINE_OUT			8
48 #define EXTCON_MICROPHONE		9
49 #define EXTCON_HEADPHONE		10
50 #define EXTCON_HDMI			11
51 #define EXTCON_MHL			12
52 #define EXTCON_DVI			13
53 #define EXTCON_VGA			14
54 #define EXTCON_SPDIF_IN			15
55 #define EXTCON_SPDIF_OUT		16
56 #define EXTCON_VIDEO_IN			17
57 #define EXTCON_VIDEO_OUT		18
58 
59 #define EXTCON_DOCK			19	/* Misc connector */
60 #define EXTCON_JIG			20
61 #define EXTCON_MECHANICAL		21
62 
63 struct extcon_cable;
64 
65 /**
66  * struct extcon_dev - An extcon device represents one external connector.
67  * @name:		The name of this extcon device. Parent device name is
68  *			used if NULL.
69  * @supported_cable:	Array of supported cable names ending with EXTCON_NONE.
70  *			If supported_cable is NULL, cable name related APIs
71  *			are disabled.
72  * @mutually_exclusive:	Array of mutually exclusive set of cables that cannot
73  *			be attached simultaneously. The array should be
74  *			ending with NULL or be NULL (no mutually exclusive
75  *			cables). For example, if it is { 0x7, 0x30, 0}, then,
76  *			{0, 1}, {0, 1, 2}, {0, 2}, {1, 2}, or {4, 5} cannot
77  *			be attached simulataneously. {0x7, 0} is equivalent to
78  *			{0x3, 0x6, 0x5, 0}. If it is {0xFFFFFFFF, 0}, there
79  *			can be no simultaneous connections.
80  * @print_state:	An optional callback to override the method to print the
81  *			status of the extcon device.
82  * @dev:		Device of this extcon.
83  * @state:		Attach/detach state of this extcon. Do not provide at
84  *			register-time.
85  * @nh:			Notifier for the state change events from this extcon
86  * @entry:		To support list of extcon devices so that users can
87  *			search for extcon devices based on the extcon name.
88  * @lock:
89  * @max_supported:	Internal value to store the number of cables.
90  * @extcon_dev_type:	Device_type struct to provide attribute_groups
91  *			customized for each extcon device.
92  * @cables:		Sysfs subdirectories. Each represents one cable.
93  *
94  * In most cases, users only need to provide "User initializing data" of
95  * this struct when registering an extcon. In some exceptional cases,
96  * optional callbacks may be needed. However, the values in "internal data"
97  * are overwritten by register function.
98  */
99 struct extcon_dev {
100 	/* Optional user initializing data */
101 	const char *name;
102 	const unsigned int *supported_cable;
103 	const u32 *mutually_exclusive;
104 
105 	/* Optional callbacks to override class functions */
106 	ssize_t	(*print_state)(struct extcon_dev *edev, char *buf);
107 
108 	/* Internal data. Please do not set. */
109 	struct device dev;
110 	struct raw_notifier_head *nh;
111 	struct list_head entry;
112 	int max_supported;
113 	spinlock_t lock;	/* could be called by irq handler */
114 	u32 state;
115 
116 	/* /sys/class/extcon/.../cable.n/... */
117 	struct device_type extcon_dev_type;
118 	struct extcon_cable *cables;
119 
120 	/* /sys/class/extcon/.../mutually_exclusive/... */
121 	struct attribute_group attr_g_muex;
122 	struct attribute **attrs_muex;
123 	struct device_attribute *d_attrs_muex;
124 };
125 
126 /**
127  * struct extcon_cable - An internal data for each cable of extcon device.
128  * @edev:		The extcon device
129  * @cable_index:	Index of this cable in the edev
130  * @attr_g:		Attribute group for the cable
131  * @attr_name:		"name" sysfs entry
132  * @attr_state:		"state" sysfs entry
133  * @attrs:		Array pointing to attr_name and attr_state for attr_g
134  */
135 struct extcon_cable {
136 	struct extcon_dev *edev;
137 	int cable_index;
138 
139 	struct attribute_group attr_g;
140 	struct device_attribute attr_name;
141 	struct device_attribute attr_state;
142 
143 	struct attribute *attrs[3]; /* to be fed to attr_g.attrs */
144 };
145 
146 /**
147  * struct extcon_specific_cable_nb - An internal data for
148  *				     extcon_register_interest().
149  * @user_nb:		user provided notifier block for events from
150  *			a specific cable.
151  * @cable_index:	the target cable.
152  * @edev:		the target extcon device.
153  * @previous_value:	the saved previous event value.
154  */
155 struct extcon_specific_cable_nb {
156 	struct notifier_block *user_nb;
157 	int cable_index;
158 	struct extcon_dev *edev;
159 	unsigned long previous_value;
160 };
161 
162 #if IS_ENABLED(CONFIG_EXTCON)
163 
164 /*
165  * Following APIs are for notifiers or configurations.
166  * Notifiers are the external port and connection devices.
167  */
168 extern int extcon_dev_register(struct extcon_dev *edev);
169 extern void extcon_dev_unregister(struct extcon_dev *edev);
170 extern int devm_extcon_dev_register(struct device *dev,
171 				    struct extcon_dev *edev);
172 extern void devm_extcon_dev_unregister(struct device *dev,
173 				       struct extcon_dev *edev);
174 extern struct extcon_dev *extcon_get_extcon_dev(const char *extcon_name);
175 
176 /*
177  * Following APIs control the memory of extcon device.
178  */
179 extern struct extcon_dev *extcon_dev_allocate(const unsigned int *cable);
180 extern void extcon_dev_free(struct extcon_dev *edev);
181 extern struct extcon_dev *devm_extcon_dev_allocate(struct device *dev,
182 						   const unsigned int *cable);
183 extern void devm_extcon_dev_free(struct device *dev, struct extcon_dev *edev);
184 
185 /*
186  * get/set/update_state access the 32b encoded state value, which represents
187  * states of all possible cables of the multistate port. For example, if one
188  * calls extcon_set_state(edev, 0x7), it may mean that all the three cables
189  * are attached to the port.
190  */
191 static inline u32 extcon_get_state(struct extcon_dev *edev)
192 {
193 	return edev->state;
194 }
195 
196 extern int extcon_set_state(struct extcon_dev *edev, u32 state);
197 extern int extcon_update_state(struct extcon_dev *edev, u32 mask, u32 state);
198 
199 /*
200  * get/set_cable_state access each bit of the 32b encoded state value.
201  * They are used to access the status of each cable based on the cable_name.
202  */
203 extern int extcon_get_cable_state_(struct extcon_dev *edev, unsigned int id);
204 extern int extcon_set_cable_state_(struct extcon_dev *edev, unsigned int id,
205 				   bool cable_state);
206 
207 extern int extcon_get_cable_state(struct extcon_dev *edev,
208 				  const char *cable_name);
209 extern int extcon_set_cable_state(struct extcon_dev *edev,
210 				  const char *cable_name, bool cable_state);
211 
212 /*
213  * Following APIs are for notifiees (those who want to be notified)
214  * to register a callback for events from a specific cable of the extcon.
215  * Notifiees are the connected device drivers wanting to get notified by
216  * a specific external port of a connection device.
217  */
218 extern int extcon_register_interest(struct extcon_specific_cable_nb *obj,
219 				    const char *extcon_name,
220 				    const char *cable_name,
221 				    struct notifier_block *nb);
222 extern int extcon_unregister_interest(struct extcon_specific_cable_nb *nb);
223 
224 /*
225  * Following APIs are to monitor every action of a notifier.
226  * Registrar gets notified for every external port of a connection device.
227  * Probably this could be used to debug an action of notifier; however,
228  * we do not recommend to use this for normal 'notifiee' device drivers who
229  * want to be notified by a specific external port of the notifier.
230  */
231 extern int extcon_register_notifier(struct extcon_dev *edev, unsigned int id,
232 				    struct notifier_block *nb);
233 extern int extcon_unregister_notifier(struct extcon_dev *edev, unsigned int id,
234 				    struct notifier_block *nb);
235 
236 /*
237  * Following API get the extcon device from devicetree.
238  * This function use phandle of devicetree to get extcon device directly.
239  */
240 extern struct extcon_dev *extcon_get_edev_by_phandle(struct device *dev,
241 						     int index);
242 
243 /* Following API to get information of extcon device */
244 extern const char *extcon_get_edev_name(struct extcon_dev *edev);
245 
246 #else /* CONFIG_EXTCON */
247 static inline int extcon_dev_register(struct extcon_dev *edev)
248 {
249 	return 0;
250 }
251 
252 static inline void extcon_dev_unregister(struct extcon_dev *edev) { }
253 
254 static inline int devm_extcon_dev_register(struct device *dev,
255 					   struct extcon_dev *edev)
256 {
257 	return -EINVAL;
258 }
259 
260 static inline void devm_extcon_dev_unregister(struct device *dev,
261 					      struct extcon_dev *edev) { }
262 
263 static inline struct extcon_dev *extcon_dev_allocate(const unsigned int *cable)
264 {
265 	return ERR_PTR(-ENOSYS);
266 }
267 
268 static inline void extcon_dev_free(struct extcon_dev *edev) { }
269 
270 static inline struct extcon_dev *devm_extcon_dev_allocate(struct device *dev,
271 						const unsigned int *cable)
272 {
273 	return ERR_PTR(-ENOSYS);
274 }
275 
276 static inline void devm_extcon_dev_free(struct extcon_dev *edev) { }
277 
278 static inline u32 extcon_get_state(struct extcon_dev *edev)
279 {
280 	return 0;
281 }
282 
283 static inline int extcon_set_state(struct extcon_dev *edev, u32 state)
284 {
285 	return 0;
286 }
287 
288 static inline int extcon_update_state(struct extcon_dev *edev, u32 mask,
289 				       u32 state)
290 {
291 	return 0;
292 }
293 
294 static inline int extcon_get_cable_state_(struct extcon_dev *edev,
295 					  unsigned int id)
296 {
297 	return 0;
298 }
299 
300 static inline int extcon_set_cable_state_(struct extcon_dev *edev,
301 					  unsigned int id, bool cable_state)
302 {
303 	return 0;
304 }
305 
306 static inline int extcon_get_cable_state(struct extcon_dev *edev,
307 			const char *cable_name)
308 {
309 	return 0;
310 }
311 
312 static inline int extcon_set_cable_state(struct extcon_dev *edev,
313 			const char *cable_name, int state)
314 {
315 	return 0;
316 }
317 
318 static inline struct extcon_dev *extcon_get_extcon_dev(const char *extcon_name)
319 {
320 	return NULL;
321 }
322 
323 static inline int extcon_register_notifier(struct extcon_dev *edev,
324 					unsigned int id,
325 					struct notifier_block *nb)
326 {
327 	return 0;
328 }
329 
330 static inline int extcon_unregister_notifier(struct extcon_dev *edev,
331 					unsigned int id,
332 					struct notifier_block *nb)
333 {
334 	return 0;
335 }
336 
337 static inline int extcon_register_interest(struct extcon_specific_cable_nb *obj,
338 					   const char *extcon_name,
339 					   const char *cable_name,
340 					   struct notifier_block *nb)
341 {
342 	return 0;
343 }
344 
345 static inline int extcon_unregister_interest(struct extcon_specific_cable_nb
346 						    *obj)
347 {
348 	return 0;
349 }
350 
351 static inline struct extcon_dev *extcon_get_edev_by_phandle(struct device *dev,
352 							    int index)
353 {
354 	return ERR_PTR(-ENODEV);
355 }
356 #endif /* CONFIG_EXTCON */
357 #endif /* __LINUX_EXTCON_H__ */
358