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1/*
2 * External connector (extcon) class driver
3 *
4 * Copyright (C) 2012 Samsung Electronics
5 * Author: Donggeun Kim <dg77.kim@samsung.com>
6 * Author: MyungJoo Ham <myungjoo.ham@samsung.com>
7 *
8 * based on switch class driver
9 * Copyright (C) 2008 Google, Inc.
10 * Author: Mike Lockwood <lockwood@android.com>
11 *
12 * This software is licensed under the terms of the GNU General Public
13 * License version 2, as published by the Free Software Foundation, and
14 * may be copied, distributed, and modified under those terms.
15 *
16 * This program is distributed in the hope that it will be useful,
17 * but WITHOUT ANY WARRANTY; without even the implied warranty of
18 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
19 * GNU General Public License for more details.
20 *
21*/
22
23#ifndef __LINUX_EXTCON_H__
24#define __LINUX_EXTCON_H__
25
26#include <linux/notifier.h>
27
28#define SUPPORTED_CABLE_MAX 32
29#define CABLE_NAME_MAX 30
30
31/*
32 * The standard cable name is to help support general notifier
33 * and notifee device drivers to share the common names.
34 * Please use standard cable names unless your notifier device has
35 * a very unique and abnormal cable or
36 * the cable type is supposed to be used with only one unique
37 * pair of notifier/notifee devices.
38 *
39 * Please add any other "standard" cables used with extcon dev.
40 *
41 * You may add a dot and number to specify version or specification
42 * of the specific cable if it is required. (e.g., "Fast-charger.18"
43 * and "Fast-charger.10" for 1.8A and 1.0A chargers)
44 * However, the notifee and notifier should be able to handle such
45 * string and if the notifee can negotiate the protocol or idenify,
46 * you don't need such convention. This convention is helpful when
47 * notifier can distinguish but notifiee cannot.
48 */
49enum extcon_cable_name {
50 EXTCON_USB = 0,
51 EXTCON_USB_HOST,
52 EXTCON_TA, /* Travel Adaptor */
53 EXTCON_FAST_CHARGER,
54 EXTCON_SLOW_CHARGER,
55 EXTCON_CHARGE_DOWNSTREAM, /* Charging an external device */
56 EXTCON_HDMI,
57 EXTCON_MHL,
58 EXTCON_DVI,
59 EXTCON_VGA,
60 EXTCON_DOCK,
61 EXTCON_LINE_IN,
62 EXTCON_LINE_OUT,
63 EXTCON_MIC_IN,
64 EXTCON_HEADPHONE_OUT,
65 EXTCON_SPDIF_IN,
66 EXTCON_SPDIF_OUT,
67 EXTCON_VIDEO_IN,
68 EXTCON_VIDEO_OUT,
69 EXTCON_MECHANICAL,
70};
71extern const char *extcon_cable_name[];
72
73struct extcon_cable;
74
75/**
76 * struct extcon_dev - An extcon device represents one external connector.
77 * @name The name of this extcon device. Parent device name is used
78 * if NULL.
79 * @supported_cable Array of supported cable name ending with NULL.
80 * If supported_cable is NULL, cable name related APIs
81 * are disabled.
82 * @mutually_exclusive Array of mutually exclusive set of cables that cannot
83 * be attached simultaneously. The array should be
84 * ending with NULL or be NULL (no mutually exclusive
85 * cables). For example, if it is { 0x7, 0x30, 0}, then,
86 * {0, 1}, {0, 1, 2}, {0, 2}, {1, 2}, or {4, 5} cannot
87 * be attached simulataneously. {0x7, 0} is equivalent to
88 * {0x3, 0x6, 0x5, 0}. If it is {0xFFFFFFFF, 0}, there
89 * can be no simultaneous connections.
90 * @print_name An optional callback to override the method to print the
91 * name of the extcon device.
92 * @print_state An optional callback to override the method to print the
93 * status of the extcon device.
94 * @dev Device of this extcon. Do not provide at register-time.
95 * @state Attach/detach state of this extcon. Do not provide at
96 * register-time
97 * @nh Notifier for the state change events from this extcon
98 * @entry To support list of extcon devices so that uses can search
99 * for extcon devices based on the extcon name.
100 * @lock
101 * @max_supported Internal value to store the number of cables.
102 * @extcon_dev_type Device_type struct to provide attribute_groups
103 * customized for each extcon device.
104 * @cables Sysfs subdirectories. Each represents one cable.
105 *
106 * In most cases, users only need to provide "User initializing data" of
107 * this struct when registering an extcon. In some exceptional cases,
108 * optional callbacks may be needed. However, the values in "internal data"
109 * are overwritten by register function.
110 */
111struct extcon_dev {
112 /* --- Optional user initializing data --- */
113 const char *name;
114 const char **supported_cable;
115 const u32 *mutually_exclusive;
116
117 /* --- Optional callbacks to override class functions --- */
118 ssize_t (*print_name)(struct extcon_dev *edev, char *buf);
119 ssize_t (*print_state)(struct extcon_dev *edev, char *buf);
120
121 /* --- Internal data. Please do not set. --- */
122 struct device *dev;
123 u32 state;
124 struct raw_notifier_head nh;
125 struct list_head entry;
126 spinlock_t lock; /* could be called by irq handler */
127 int max_supported;
128
129 /* /sys/class/extcon/.../cable.n/... */
130 struct device_type extcon_dev_type;
131 struct extcon_cable *cables;
132 /* /sys/class/extcon/.../mutually_exclusive/... */
133 struct attribute_group attr_g_muex;
134 struct attribute **attrs_muex;
135 struct device_attribute *d_attrs_muex;
136};
137
138/**
139 * struct extcon_cable - An internal data for each cable of extcon device.
140 * @edev The extcon device
141 * @cable_index Index of this cable in the edev
142 * @attr_g Attribute group for the cable
143 * @attr_name "name" sysfs entry
144 * @attr_state "state" sysfs entry
145 * @attrs Array pointing to attr_name and attr_state for attr_g
146 */
147struct extcon_cable {
148 struct extcon_dev *edev;
149 int cable_index;
150
151 struct attribute_group attr_g;
152 struct device_attribute attr_name;
153 struct device_attribute attr_state;
154
155 struct attribute *attrs[3]; /* to be fed to attr_g.attrs */
156};
157
158/**
159 * struct extcon_specific_cable_nb - An internal data for
160 * extcon_register_interest().
161 * @internal_nb a notifier block bridging extcon notifier and cable notifier.
162 * @user_nb user provided notifier block for events from a specific cable.
163 * @cable_index the target cable.
164 * @edev the target extcon device.
165 * @previous_value the saved previous event value.
166 */
167struct extcon_specific_cable_nb {
168 struct notifier_block internal_nb;
169 struct notifier_block *user_nb;
170 int cable_index;
171 struct extcon_dev *edev;
172 unsigned long previous_value;
173};
174
175#if IS_ENABLED(CONFIG_EXTCON)
176
177/*
178 * Following APIs are for notifiers or configurations.
179 * Notifiers are the external port and connection devices.
180 */
181extern int extcon_dev_register(struct extcon_dev *edev, struct device *dev);
182extern void extcon_dev_unregister(struct extcon_dev *edev);
183extern struct extcon_dev *extcon_get_extcon_dev(const char *extcon_name);
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 */
191static inline u32 extcon_get_state(struct extcon_dev *edev)
192{
193 return edev->state;
194}
195
196extern int extcon_set_state(struct extcon_dev *edev, u32 state);
197extern 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 * or cable_index, which is retrived by extcon_find_cable_index
203 */
204extern int extcon_find_cable_index(struct extcon_dev *sdev,
205 const char *cable_name);
206extern int extcon_get_cable_state_(struct extcon_dev *edev, int cable_index);
207extern int extcon_set_cable_state_(struct extcon_dev *edev, int cable_index,
208 bool cable_state);
209
210extern int extcon_get_cable_state(struct extcon_dev *edev,
211 const char *cable_name);
212extern int extcon_set_cable_state(struct extcon_dev *edev,
213 const char *cable_name, bool cable_state);
214
215/*
216 * Following APIs are for notifiees (those who want to be notified)
217 * to register a callback for events from a specific cable of the extcon.
218 * Notifiees are the connected device drivers wanting to get notified by
219 * a specific external port of a connection device.
220 */
221extern int extcon_register_interest(struct extcon_specific_cable_nb *obj,
222 const char *extcon_name,
223 const char *cable_name,
224 struct notifier_block *nb);
225extern int extcon_unregister_interest(struct extcon_specific_cable_nb *nb);
226
227/*
228 * Following APIs are to monitor every action of a notifier.
229 * Registerer gets notified for every external port of a connection device.
230 * Probably this could be used to debug an action of notifier; however,
231 * we do not recommend to use this at normal 'notifiee' device drivers who
232 * want to be notified by a specific external port of the notifier.
233 */
234extern int extcon_register_notifier(struct extcon_dev *edev,
235 struct notifier_block *nb);
236extern int extcon_unregister_notifier(struct extcon_dev *edev,
237 struct notifier_block *nb);
238#else /* CONFIG_EXTCON */
239static inline int extcon_dev_register(struct extcon_dev *edev,
240 struct device *dev)
241{
242 return 0;
243}
244
245static inline void extcon_dev_unregister(struct extcon_dev *edev) { }
246
247static inline u32 extcon_get_state(struct extcon_dev *edev)
248{
249 return 0;
250}
251
252static inline int extcon_set_state(struct extcon_dev *edev, u32 state)
253{
254 return 0;
255}
256
257static inline int extcon_update_state(struct extcon_dev *edev, u32 mask,
258 u32 state)
259{
260 return 0;
261}
262
263static inline int extcon_find_cable_index(struct extcon_dev *edev,
264 const char *cable_name)
265{
266 return 0;
267}
268
269static inline int extcon_get_cable_state_(struct extcon_dev *edev,
270 int cable_index)
271{
272 return 0;
273}
274
275static inline int extcon_set_cable_state_(struct extcon_dev *edev,
276 int cable_index, bool cable_state)
277{
278 return 0;
279}
280
281static inline int extcon_get_cable_state(struct extcon_dev *edev,
282 const char *cable_name)
283{
284 return 0;
285}
286
287static inline int extcon_set_cable_state(struct extcon_dev *edev,
288 const char *cable_name, int state)
289{
290 return 0;
291}
292
293static inline struct extcon_dev *extcon_get_extcon_dev(const char *extcon_name)
294{
295 return NULL;
296}
297
298static inline int extcon_register_notifier(struct extcon_dev *edev,
299 struct notifier_block *nb)
300{
301 return 0;
302}
303
304static inline int extcon_unregister_notifier(struct extcon_dev *edev,
305 struct notifier_block *nb)
306{
307 return 0;
308}
309
310static inline int extcon_register_interest(struct extcon_specific_cable_nb *obj,
311 const char *extcon_name,
312 const char *cable_name,
313 struct notifier_block *nb)
314{
315 return 0;
316}
317
318static inline int extcon_unregister_interest(struct extcon_specific_cable_nb
319 *obj)
320{
321 return 0;
322}
323#endif /* CONFIG_EXTCON */
324#endif /* __LINUX_EXTCON_H__ */
generated by cgit v1.2.2 (git 2.25.0) at 2025-09-21 01:19:01 -0400