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/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 */ 51enum 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}; 73extern const char extcon_cable_name[][CABLE_NAME_MAX + 1]; 74 75struct 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 80 * used 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. 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 */ 113struct 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 struct raw_notifier_head nh; 126 struct list_head entry; 127 int max_supported; 128 spinlock_t lock; /* could be called by irq handler */ 129 u32 state; 130 131 /* /sys/class/extcon/.../cable.n/... */ 132 struct device_type extcon_dev_type; 133 struct extcon_cable *cables; 134 135 /* /sys/class/extcon/.../mutually_exclusive/... */ 136 struct attribute_group attr_g_muex; 137 struct attribute **attrs_muex; 138 struct device_attribute *d_attrs_muex; 139}; 140 141/** 142 * struct extcon_cable - An internal data for each cable of extcon device. 143 * @edev: The extcon device 144 * @cable_index: Index of this cable in the edev 145 * @attr_g: Attribute group for the cable 146 * @attr_name: "name" sysfs entry 147 * @attr_state: "state" sysfs entry 148 * @attrs: Array pointing to attr_name and attr_state for attr_g 149 */ 150struct extcon_cable { 151 struct extcon_dev *edev; 152 int cable_index; 153 154 struct attribute_group attr_g; 155 struct device_attribute attr_name; 156 struct device_attribute attr_state; 157 158 struct attribute *attrs[3]; /* to be fed to attr_g.attrs */ 159}; 160 161/** 162 * struct extcon_specific_cable_nb - An internal data for 163 * extcon_register_interest(). 164 * @internal_nb: A notifier block bridging extcon notifier 165 * and cable notifier. 166 * @user_nb: user provided notifier block for events from 167 * a specific cable. 168 * @cable_index: the target cable. 169 * @edev: the target extcon device. 170 * @previous_value: the saved previous event value. 171 */ 172struct extcon_specific_cable_nb { 173 struct notifier_block internal_nb; 174 struct notifier_block *user_nb; 175 int cable_index; 176 struct extcon_dev *edev; 177 unsigned long previous_value; 178}; 179 180#if IS_ENABLED(CONFIG_EXTCON) 181 182/* 183 * Following APIs are for notifiers or configurations. 184 * Notifiers are the external port and connection devices. 185 */ 186extern int extcon_dev_register(struct extcon_dev *edev); 187extern void extcon_dev_unregister(struct extcon_dev *edev); 188extern int devm_extcon_dev_register(struct device *dev, 189 struct extcon_dev *edev); 190extern void devm_extcon_dev_unregister(struct device *dev, 191 struct extcon_dev *edev); 192extern struct extcon_dev *extcon_get_extcon_dev(const char *extcon_name); 193 194/* 195 * Following APIs control the memory of extcon device. 196 */ 197extern struct extcon_dev *extcon_dev_allocate(const char **cables); 198extern void extcon_dev_free(struct extcon_dev *edev); 199extern struct extcon_dev *devm_extcon_dev_allocate(struct device *dev, 200 const char **cables); 201extern void devm_extcon_dev_free(struct device *dev, struct extcon_dev *edev); 202 203/* 204 * get/set/update_state access the 32b encoded state value, which represents 205 * states of all possible cables of the multistate port. For example, if one 206 * calls extcon_set_state(edev, 0x7), it may mean that all the three cables 207 * are attached to the port. 208 */ 209static inline u32 extcon_get_state(struct extcon_dev *edev) 210{ 211 return edev->state; 212} 213 214extern int extcon_set_state(struct extcon_dev *edev, u32 state); 215extern int extcon_update_state(struct extcon_dev *edev, u32 mask, u32 state); 216 217/* 218 * get/set_cable_state access each bit of the 32b encoded state value. 219 * They are used to access the status of each cable based on the cable_name 220 * or cable_index, which is retrieved by extcon_find_cable_index 221 */ 222extern int extcon_find_cable_index(struct extcon_dev *sdev, 223 const char *cable_name); 224extern int extcon_get_cable_state_(struct extcon_dev *edev, int cable_index); 225extern int extcon_set_cable_state_(struct extcon_dev *edev, int cable_index, 226 bool cable_state); 227 228extern int extcon_get_cable_state(struct extcon_dev *edev, 229 const char *cable_name); 230extern int extcon_set_cable_state(struct extcon_dev *edev, 231 const char *cable_name, bool cable_state); 232 233/* 234 * Following APIs are for notifiees (those who want to be notified) 235 * to register a callback for events from a specific cable of the extcon. 236 * Notifiees are the connected device drivers wanting to get notified by 237 * a specific external port of a connection device. 238 */ 239extern int extcon_register_interest(struct extcon_specific_cable_nb *obj, 240 const char *extcon_name, 241 const char *cable_name, 242 struct notifier_block *nb); 243extern int extcon_unregister_interest(struct extcon_specific_cable_nb *nb); 244 245/* 246 * Following APIs are to monitor every action of a notifier. 247 * Registrar gets notified for every external port of a connection device. 248 * Probably this could be used to debug an action of notifier; however, 249 * we do not recommend to use this for normal 'notifiee' device drivers who 250 * want to be notified by a specific external port of the notifier. 251 */ 252extern int extcon_register_notifier(struct extcon_dev *edev, 253 struct notifier_block *nb); 254extern int extcon_unregister_notifier(struct extcon_dev *edev, 255 struct notifier_block *nb); 256 257/* 258 * Following API get the extcon device from devicetree. 259 * This function use phandle of devicetree to get extcon device directly. 260 */ 261extern struct extcon_dev *extcon_get_edev_by_phandle(struct device *dev, int index); 262#else /* CONFIG_EXTCON */ 263static inline int extcon_dev_register(struct extcon_dev *edev) 264{ 265 return 0; 266} 267 268static inline void extcon_dev_unregister(struct extcon_dev *edev) { } 269 270static inline int devm_extcon_dev_register(struct device *dev, 271 struct extcon_dev *edev) 272{ 273 return -EINVAL; 274} 275 276static inline void devm_extcon_dev_unregister(struct device *dev, 277 struct extcon_dev *edev) { } 278 279static inline struct extcon_dev *extcon_dev_allocate(const char **cables) 280{ 281 return ERR_PTR(-ENOSYS); 282} 283 284static inline void extcon_dev_free(struct extcon_dev *edev) { } 285 286static inline struct extcon_dev *devm_extcon_dev_allocate(struct device *dev, 287 const char **cables) 288{ 289 return ERR_PTR(-ENOSYS); 290} 291 292static inline void devm_extcon_dev_free(struct extcon_dev *edev) { } 293 294static inline u32 extcon_get_state(struct extcon_dev *edev) 295{ 296 return 0; 297} 298 299static inline int extcon_set_state(struct extcon_dev *edev, u32 state) 300{ 301 return 0; 302} 303 304static inline int extcon_update_state(struct extcon_dev *edev, u32 mask, 305 u32 state) 306{ 307 return 0; 308} 309 310static inline int extcon_find_cable_index(struct extcon_dev *edev, 311 const char *cable_name) 312{ 313 return 0; 314} 315 316static inline int extcon_get_cable_state_(struct extcon_dev *edev, 317 int cable_index) 318{ 319 return 0; 320} 321 322static inline int extcon_set_cable_state_(struct extcon_dev *edev, 323 int cable_index, bool cable_state) 324{ 325 return 0; 326} 327 328static inline int extcon_get_cable_state(struct extcon_dev *edev, 329 const char *cable_name) 330{ 331 return 0; 332} 333 334static inline int extcon_set_cable_state(struct extcon_dev *edev, 335 const char *cable_name, int state) 336{ 337 return 0; 338} 339 340static inline struct extcon_dev *extcon_get_extcon_dev(const char *extcon_name) 341{ 342 return NULL; 343} 344 345static inline int extcon_register_notifier(struct extcon_dev *edev, 346 struct notifier_block *nb) 347{ 348 return 0; 349} 350 351static inline int extcon_unregister_notifier(struct extcon_dev *edev, 352 struct notifier_block *nb) 353{ 354 return 0; 355} 356 357static inline int extcon_register_interest(struct extcon_specific_cable_nb *obj, 358 const char *extcon_name, 359 const char *cable_name, 360 struct notifier_block *nb) 361{ 362 return 0; 363} 364 365static inline int extcon_unregister_interest(struct extcon_specific_cable_nb 366 *obj) 367{ 368 return 0; 369} 370 371static inline struct extcon_dev *extcon_get_edev_by_phandle(struct device *dev, 372 int index) 373{ 374 return ERR_PTR(-ENODEV); 375} 376#endif /* CONFIG_EXTCON */ 377#endif /* __LINUX_EXTCON_H__ */ 378