1 /* 2 * External connector (extcon) class driver 3 * 4 * Copyright (C) 2012 Samsung Electronics 5 * Author: Donggeun Kim <[email protected]> 6 * Author: MyungJoo Ham <[email protected]> 7 * 8 * based on switch class driver 9 * Copyright (C) 2008 Google, Inc. 10 * Author: Mike Lockwood <[email protected]> 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/device.h> 27 #include <linux/notifier.h> 28 #include <linux/sysfs.h> 29 30 #define SUPPORTED_CABLE_MAX 32 31 #define CABLE_NAME_MAX 30 32 33 /* 34 * The standard cable name is to help support general notifier 35 * and notifiee device drivers to share the common names. 36 * Please use standard cable names unless your notifier device has 37 * a very unique and abnormal cable or 38 * the cable type is supposed to be used with only one unique 39 * pair of notifier/notifiee devices. 40 * 41 * Please add any other "standard" cables used with extcon dev. 42 * 43 * You may add a dot and number to specify version or specification 44 * of the specific cable if it is required. (e.g., "Fast-charger.18" 45 * and "Fast-charger.10" for 1.8A and 1.0A chargers) 46 * However, the notifiee and notifier should be able to handle such 47 * string and if the notifiee can negotiate the protocol or identify, 48 * you don't need such convention. This convention is helpful when 49 * notifier can distinguish but notifiee cannot. 50 */ 51 enum extcon_cable_name { 52 EXTCON_USB = 0, 53 EXTCON_USB_HOST, 54 EXTCON_TA, /* Travel Adaptor */ 55 EXTCON_FAST_CHARGER, 56 EXTCON_SLOW_CHARGER, 57 EXTCON_CHARGE_DOWNSTREAM, /* Charging an external device */ 58 EXTCON_HDMI, 59 EXTCON_MHL, 60 EXTCON_DVI, 61 EXTCON_VGA, 62 EXTCON_DOCK, 63 EXTCON_LINE_IN, 64 EXTCON_LINE_OUT, 65 EXTCON_MIC_IN, 66 EXTCON_HEADPHONE_OUT, 67 EXTCON_SPDIF_IN, 68 EXTCON_SPDIF_OUT, 69 EXTCON_VIDEO_IN, 70 EXTCON_VIDEO_OUT, 71 EXTCON_MECHANICAL, 72 }; 73 extern const char extcon_cable_name[][CABLE_NAME_MAX + 1]; 74 75 struct extcon_cable; 76 77 /** 78 * struct extcon_dev - An extcon device represents one external connector. 79 * @name: The name of this extcon device. Parent device name is used 80 * if NULL. 81 * @supported_cable: Array of supported cable names ending with NULL. 82 * If supported_cable is NULL, cable name related APIs 83 * are disabled. 84 * @mutually_exclusive: Array of mutually exclusive set of cables that cannot 85 * be attached simultaneously. The array should be 86 * ending with NULL or be NULL (no mutually exclusive 87 * cables). For example, if it is { 0x7, 0x30, 0}, then, 88 * {0, 1}, {0, 1, 2}, {0, 2}, {1, 2}, or {4, 5} cannot 89 * be attached simulataneously. {0x7, 0} is equivalent to 90 * {0x3, 0x6, 0x5, 0}. If it is {0xFFFFFFFF, 0}, there 91 * can be no simultaneous connections. 92 * @print_name: An optional callback to override the method to print the 93 * name of the extcon device. 94 * @print_state: An optional callback to override the method to print the 95 * status of the extcon device. 96 * @dev: Device of this extcon. Do not provide at register-time. 97 * @state: Attach/detach state of this extcon. Do not provide at 98 * register-time 99 * @nh: Notifier for the state change events from this extcon 100 * @entry: To support list of extcon devices so that users can search 101 * for extcon devices based on the extcon name. 102 * @lock: 103 * @max_supported: Internal value to store the number of cables. 104 * @extcon_dev_type: Device_type struct to provide attribute_groups 105 * customized for each extcon device. 106 * @cables: Sysfs subdirectories. Each represents one cable. 107 * 108 * In most cases, users only need to provide "User initializing data" of 109 * this struct when registering an extcon. In some exceptional cases, 110 * optional callbacks may be needed. However, the values in "internal data" 111 * are overwritten by register function. 112 */ 113 struct extcon_dev { 114 /* --- Optional user initializing data --- */ 115 const char *name; 116 const char **supported_cable; 117 const u32 *mutually_exclusive; 118 119 /* --- Optional callbacks to override class functions --- */ 120 ssize_t (*print_name)(struct extcon_dev *edev, char *buf); 121 ssize_t (*print_state)(struct extcon_dev *edev, char *buf); 122 123 /* --- Internal data. Please do not set. --- */ 124 struct device *dev; 125 u32 state; 126 struct raw_notifier_head nh; 127 struct list_head entry; 128 spinlock_t lock; /* could be called by irq handler */ 129 int max_supported; 130 131 /* /sys/class/extcon/.../cable.n/... */ 132 struct device_type extcon_dev_type; 133 struct extcon_cable *cables; 134 /* /sys/class/extcon/.../mutually_exclusive/... */ 135 struct attribute_group attr_g_muex; 136 struct attribute **attrs_muex; 137 struct device_attribute *d_attrs_muex; 138 }; 139 140 /** 141 * struct extcon_cable - An internal data for each cable of extcon device. 142 * @edev: The extcon device 143 * @cable_index: Index of this cable in the edev 144 * @attr_g: Attribute group for the cable 145 * @attr_name: "name" sysfs entry 146 * @attr_state: "state" sysfs entry 147 * @attrs: Array pointing to attr_name and attr_state for attr_g 148 */ 149 struct extcon_cable { 150 struct extcon_dev *edev; 151 int cable_index; 152 153 struct attribute_group attr_g; 154 struct device_attribute attr_name; 155 struct device_attribute attr_state; 156 157 struct attribute *attrs[3]; /* to be fed to attr_g.attrs */ 158 }; 159 160 /** 161 * struct extcon_specific_cable_nb - An internal data for 162 * extcon_register_interest(). 163 * @internal_nb: a notifier block bridging extcon notifier and cable notifier. 164 * @user_nb: user provided notifier block for events from a specific cable. 165 * @cable_index: the target cable. 166 * @edev: the target extcon device. 167 * @previous_value: the saved previous event value. 168 */ 169 struct extcon_specific_cable_nb { 170 struct notifier_block internal_nb; 171 struct notifier_block *user_nb; 172 int cable_index; 173 struct extcon_dev *edev; 174 unsigned long previous_value; 175 }; 176 177 #if IS_ENABLED(CONFIG_EXTCON) 178 179 /* 180 * Following APIs are for notifiers or configurations. 181 * Notifiers are the external port and connection devices. 182 */ 183 extern int extcon_dev_register(struct extcon_dev *edev, struct device *dev); 184 extern void extcon_dev_unregister(struct extcon_dev *edev); 185 extern struct extcon_dev *extcon_get_extcon_dev(const char *extcon_name); 186 187 /* 188 * get/set/update_state access the 32b encoded state value, which represents 189 * states of all possible cables of the multistate port. For example, if one 190 * calls extcon_set_state(edev, 0x7), it may mean that all the three cables 191 * are attached to the port. 192 */ 193 static inline u32 extcon_get_state(struct extcon_dev *edev) 194 { 195 return edev->state; 196 } 197 198 extern int extcon_set_state(struct extcon_dev *edev, u32 state); 199 extern int extcon_update_state(struct extcon_dev *edev, u32 mask, u32 state); 200 201 /* 202 * get/set_cable_state access each bit of the 32b encoded state value. 203 * They are used to access the status of each cable based on the cable_name 204 * or cable_index, which is retrieved by extcon_find_cable_index 205 */ 206 extern int extcon_find_cable_index(struct extcon_dev *sdev, 207 const char *cable_name); 208 extern int extcon_get_cable_state_(struct extcon_dev *edev, int cable_index); 209 extern int extcon_set_cable_state_(struct extcon_dev *edev, int cable_index, 210 bool cable_state); 211 212 extern int extcon_get_cable_state(struct extcon_dev *edev, 213 const char *cable_name); 214 extern int extcon_set_cable_state(struct extcon_dev *edev, 215 const char *cable_name, bool cable_state); 216 217 /* 218 * Following APIs are for notifiees (those who want to be notified) 219 * to register a callback for events from a specific cable of the extcon. 220 * Notifiees are the connected device drivers wanting to get notified by 221 * a specific external port of a connection device. 222 */ 223 extern int extcon_register_interest(struct extcon_specific_cable_nb *obj, 224 const char *extcon_name, 225 const char *cable_name, 226 struct notifier_block *nb); 227 extern int extcon_unregister_interest(struct extcon_specific_cable_nb *nb); 228 229 /* 230 * Following APIs are to monitor every action of a notifier. 231 * Registrar gets notified for every external port of a connection device. 232 * Probably this could be used to debug an action of notifier; however, 233 * we do not recommend to use this for normal 'notifiee' device drivers who 234 * want to be notified by a specific external port of the notifier. 235 */ 236 extern int extcon_register_notifier(struct extcon_dev *edev, 237 struct notifier_block *nb); 238 extern int extcon_unregister_notifier(struct extcon_dev *edev, 239 struct notifier_block *nb); 240 #else /* CONFIG_EXTCON */ 241 static inline int extcon_dev_register(struct extcon_dev *edev, 242 struct device *dev) 243 { 244 return 0; 245 } 246 247 static inline void extcon_dev_unregister(struct extcon_dev *edev) { } 248 249 static inline u32 extcon_get_state(struct extcon_dev *edev) 250 { 251 return 0; 252 } 253 254 static inline int extcon_set_state(struct extcon_dev *edev, u32 state) 255 { 256 return 0; 257 } 258 259 static inline int extcon_update_state(struct extcon_dev *edev, u32 mask, 260 u32 state) 261 { 262 return 0; 263 } 264 265 static inline int extcon_find_cable_index(struct extcon_dev *edev, 266 const char *cable_name) 267 { 268 return 0; 269 } 270 271 static inline int extcon_get_cable_state_(struct extcon_dev *edev, 272 int cable_index) 273 { 274 return 0; 275 } 276 277 static inline int extcon_set_cable_state_(struct extcon_dev *edev, 278 int cable_index, bool cable_state) 279 { 280 return 0; 281 } 282 283 static inline int extcon_get_cable_state(struct extcon_dev *edev, 284 const char *cable_name) 285 { 286 return 0; 287 } 288 289 static inline int extcon_set_cable_state(struct extcon_dev *edev, 290 const char *cable_name, int state) 291 { 292 return 0; 293 } 294 295 static inline struct extcon_dev *extcon_get_extcon_dev(const char *extcon_name) 296 { 297 return NULL; 298 } 299 300 static inline int extcon_register_notifier(struct extcon_dev *edev, 301 struct notifier_block *nb) 302 { 303 return 0; 304 } 305 306 static inline int extcon_unregister_notifier(struct extcon_dev *edev, 307 struct notifier_block *nb) 308 { 309 return 0; 310 } 311 312 static inline int extcon_register_interest(struct extcon_specific_cable_nb *obj, 313 const char *extcon_name, 314 const char *cable_name, 315 struct notifier_block *nb) 316 { 317 return 0; 318 } 319 320 static inline int extcon_unregister_interest(struct extcon_specific_cable_nb 321 *obj) 322 { 323 return 0; 324 } 325 #endif /* CONFIG_EXTCON */ 326 #endif /* __LINUX_EXTCON_H__ */ 327