xref: /linux-6.15/include/linux/extcon.h (revision 32ae976e)
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 
31 /*
32  * Define the unique id of supported external connectors
33  */
34 #define EXTCON_NONE			0
35 
36 #define EXTCON_USB			1	/* USB connector */
37 #define EXTCON_USB_HOST			2
38 
39 #define EXTCON_TA			3	/* Charger connector */
40 #define EXTCON_FAST_CHARGER		4
41 #define EXTCON_SLOW_CHARGER		5
42 #define EXTCON_CHARGE_DOWNSTREAM	6
43 
44 #define EXTCON_LINE_IN			7	/* Audio/Video connector */
45 #define EXTCON_LINE_OUT			8
46 #define EXTCON_MICROPHONE		9
47 #define EXTCON_HEADPHONE		10
48 #define EXTCON_HDMI			11
49 #define EXTCON_MHL			12
50 #define EXTCON_DVI			13
51 #define EXTCON_VGA			14
52 #define EXTCON_SPDIF_IN			15
53 #define EXTCON_SPDIF_OUT		16
54 #define EXTCON_VIDEO_IN			17
55 #define EXTCON_VIDEO_OUT		18
56 
57 #define EXTCON_DOCK			19	/* Misc connector */
58 #define EXTCON_JIG			20
59 #define EXTCON_MECHANICAL		21
60 
61 struct extcon_cable;
62 
63 /**
64  * struct extcon_dev - An extcon device represents one external connector.
65  * @name:		The name of this extcon device. Parent device name is
66  *			used if NULL.
67  * @supported_cable:	Array of supported cable names ending with EXTCON_NONE.
68  *			If supported_cable is NULL, cable name related APIs
69  *			are disabled.
70  * @mutually_exclusive:	Array of mutually exclusive set of cables that cannot
71  *			be attached simultaneously. The array should be
72  *			ending with NULL or be NULL (no mutually exclusive
73  *			cables). For example, if it is { 0x7, 0x30, 0}, then,
74  *			{0, 1}, {0, 1, 2}, {0, 2}, {1, 2}, or {4, 5} cannot
75  *			be attached simulataneously. {0x7, 0} is equivalent to
76  *			{0x3, 0x6, 0x5, 0}. If it is {0xFFFFFFFF, 0}, there
77  *			can be no simultaneous connections.
78  * @dev:		Device of this extcon.
79  * @state:		Attach/detach state of this extcon. Do not provide at
80  *			register-time.
81  * @nh:			Notifier for the state change events from this extcon
82  * @entry:		To support list of extcon devices so that users can
83  *			search for extcon devices based on the extcon name.
84  * @lock:
85  * @max_supported:	Internal value to store the number of cables.
86  * @extcon_dev_type:	Device_type struct to provide attribute_groups
87  *			customized for each extcon device.
88  * @cables:		Sysfs subdirectories. Each represents one cable.
89  *
90  * In most cases, users only need to provide "User initializing data" of
91  * this struct when registering an extcon. In some exceptional cases,
92  * optional callbacks may be needed. However, the values in "internal data"
93  * are overwritten by register function.
94  */
95 struct extcon_dev {
96 	/* Optional user initializing data */
97 	const char *name;
98 	const unsigned int *supported_cable;
99 	const u32 *mutually_exclusive;
100 
101 	/* Internal data. Please do not set. */
102 	struct device dev;
103 	struct raw_notifier_head *nh;
104 	struct list_head entry;
105 	int max_supported;
106 	spinlock_t lock;	/* could be called by irq handler */
107 	u32 state;
108 
109 	/* /sys/class/extcon/.../cable.n/... */
110 	struct device_type extcon_dev_type;
111 	struct extcon_cable *cables;
112 
113 	/* /sys/class/extcon/.../mutually_exclusive/... */
114 	struct attribute_group attr_g_muex;
115 	struct attribute **attrs_muex;
116 	struct device_attribute *d_attrs_muex;
117 };
118 
119 /**
120  * struct extcon_cable - An internal data for each cable of extcon device.
121  * @edev:		The extcon device
122  * @cable_index:	Index of this cable in the edev
123  * @attr_g:		Attribute group for the cable
124  * @attr_name:		"name" sysfs entry
125  * @attr_state:		"state" sysfs entry
126  * @attrs:		Array pointing to attr_name and attr_state for attr_g
127  */
128 struct extcon_cable {
129 	struct extcon_dev *edev;
130 	int cable_index;
131 
132 	struct attribute_group attr_g;
133 	struct device_attribute attr_name;
134 	struct device_attribute attr_state;
135 
136 	struct attribute *attrs[3]; /* to be fed to attr_g.attrs */
137 };
138 
139 /**
140  * struct extcon_specific_cable_nb - An internal data for
141  *				     extcon_register_interest().
142  * @user_nb:		user provided notifier block for events from
143  *			a specific cable.
144  * @cable_index:	the target cable.
145  * @edev:		the target extcon device.
146  * @previous_value:	the saved previous event value.
147  */
148 struct extcon_specific_cable_nb {
149 	struct notifier_block *user_nb;
150 	int cable_index;
151 	struct extcon_dev *edev;
152 	unsigned long previous_value;
153 };
154 
155 #if IS_ENABLED(CONFIG_EXTCON)
156 
157 /*
158  * Following APIs are for notifiers or configurations.
159  * Notifiers are the external port and connection devices.
160  */
161 extern int extcon_dev_register(struct extcon_dev *edev);
162 extern void extcon_dev_unregister(struct extcon_dev *edev);
163 extern int devm_extcon_dev_register(struct device *dev,
164 				    struct extcon_dev *edev);
165 extern void devm_extcon_dev_unregister(struct device *dev,
166 				       struct extcon_dev *edev);
167 extern struct extcon_dev *extcon_get_extcon_dev(const char *extcon_name);
168 
169 /*
170  * Following APIs control the memory of extcon device.
171  */
172 extern struct extcon_dev *extcon_dev_allocate(const unsigned int *cable);
173 extern void extcon_dev_free(struct extcon_dev *edev);
174 extern struct extcon_dev *devm_extcon_dev_allocate(struct device *dev,
175 						   const unsigned int *cable);
176 extern void devm_extcon_dev_free(struct device *dev, struct extcon_dev *edev);
177 
178 /*
179  * get/set/update_state access the 32b encoded state value, which represents
180  * states of all possible cables of the multistate port. For example, if one
181  * calls extcon_set_state(edev, 0x7), it may mean that all the three cables
182  * are attached to the port.
183  */
184 static inline u32 extcon_get_state(struct extcon_dev *edev)
185 {
186 	return edev->state;
187 }
188 
189 extern int extcon_set_state(struct extcon_dev *edev, u32 state);
190 extern int extcon_update_state(struct extcon_dev *edev, u32 mask, u32 state);
191 
192 /*
193  * get/set_cable_state access each bit of the 32b encoded state value.
194  * They are used to access the status of each cable based on the cable_name.
195  */
196 extern int extcon_get_cable_state_(struct extcon_dev *edev, unsigned int id);
197 extern int extcon_set_cable_state_(struct extcon_dev *edev, unsigned int id,
198 				   bool cable_state);
199 
200 extern int extcon_get_cable_state(struct extcon_dev *edev,
201 				  const char *cable_name);
202 extern int extcon_set_cable_state(struct extcon_dev *edev,
203 				  const char *cable_name, bool cable_state);
204 
205 /*
206  * Following APIs are for notifiees (those who want to be notified)
207  * to register a callback for events from a specific cable of the extcon.
208  * Notifiees are the connected device drivers wanting to get notified by
209  * a specific external port of a connection device.
210  */
211 extern int extcon_register_interest(struct extcon_specific_cable_nb *obj,
212 				    const char *extcon_name,
213 				    const char *cable_name,
214 				    struct notifier_block *nb);
215 extern int extcon_unregister_interest(struct extcon_specific_cable_nb *nb);
216 
217 /*
218  * Following APIs are to monitor every action of a notifier.
219  * Registrar gets notified for every external port of a connection device.
220  * Probably this could be used to debug an action of notifier; however,
221  * we do not recommend to use this for normal 'notifiee' device drivers who
222  * want to be notified by a specific external port of the notifier.
223  */
224 extern int extcon_register_notifier(struct extcon_dev *edev, unsigned int id,
225 				    struct notifier_block *nb);
226 extern int extcon_unregister_notifier(struct extcon_dev *edev, unsigned int id,
227 				    struct notifier_block *nb);
228 
229 /*
230  * Following API get the extcon device from devicetree.
231  * This function use phandle of devicetree to get extcon device directly.
232  */
233 extern struct extcon_dev *extcon_get_edev_by_phandle(struct device *dev,
234 						     int index);
235 
236 /* Following API to get information of extcon device */
237 extern const char *extcon_get_edev_name(struct extcon_dev *edev);
238 
239 #else /* CONFIG_EXTCON */
240 static inline int extcon_dev_register(struct extcon_dev *edev)
241 {
242 	return 0;
243 }
244 
245 static inline void extcon_dev_unregister(struct extcon_dev *edev) { }
246 
247 static inline int devm_extcon_dev_register(struct device *dev,
248 					   struct extcon_dev *edev)
249 {
250 	return -EINVAL;
251 }
252 
253 static inline void devm_extcon_dev_unregister(struct device *dev,
254 					      struct extcon_dev *edev) { }
255 
256 static inline struct extcon_dev *extcon_dev_allocate(const unsigned int *cable)
257 {
258 	return ERR_PTR(-ENOSYS);
259 }
260 
261 static inline void extcon_dev_free(struct extcon_dev *edev) { }
262 
263 static inline struct extcon_dev *devm_extcon_dev_allocate(struct device *dev,
264 						const unsigned int *cable)
265 {
266 	return ERR_PTR(-ENOSYS);
267 }
268 
269 static inline void devm_extcon_dev_free(struct extcon_dev *edev) { }
270 
271 static inline u32 extcon_get_state(struct extcon_dev *edev)
272 {
273 	return 0;
274 }
275 
276 static inline int extcon_set_state(struct extcon_dev *edev, u32 state)
277 {
278 	return 0;
279 }
280 
281 static inline int extcon_update_state(struct extcon_dev *edev, u32 mask,
282 				       u32 state)
283 {
284 	return 0;
285 }
286 
287 static inline int extcon_get_cable_state_(struct extcon_dev *edev,
288 					  unsigned int id)
289 {
290 	return 0;
291 }
292 
293 static inline int extcon_set_cable_state_(struct extcon_dev *edev,
294 					  unsigned int id, bool cable_state)
295 {
296 	return 0;
297 }
298 
299 static inline int extcon_get_cable_state(struct extcon_dev *edev,
300 			const char *cable_name)
301 {
302 	return 0;
303 }
304 
305 static inline int extcon_set_cable_state(struct extcon_dev *edev,
306 			const char *cable_name, int state)
307 {
308 	return 0;
309 }
310 
311 static inline struct extcon_dev *extcon_get_extcon_dev(const char *extcon_name)
312 {
313 	return NULL;
314 }
315 
316 static inline int extcon_register_notifier(struct extcon_dev *edev,
317 					unsigned int id,
318 					struct notifier_block *nb)
319 {
320 	return 0;
321 }
322 
323 static inline int extcon_unregister_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_register_interest(struct extcon_specific_cable_nb *obj,
331 					   const char *extcon_name,
332 					   const char *cable_name,
333 					   struct notifier_block *nb)
334 {
335 	return 0;
336 }
337 
338 static inline int extcon_unregister_interest(struct extcon_specific_cable_nb
339 						    *obj)
340 {
341 	return 0;
342 }
343 
344 static inline struct extcon_dev *extcon_get_edev_by_phandle(struct device *dev,
345 							    int index)
346 {
347 	return ERR_PTR(-ENODEV);
348 }
349 #endif /* CONFIG_EXTCON */
350 #endif /* __LINUX_EXTCON_H__ */
351