include/linux/extcon.h

   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  */
  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
  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  */
 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         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         device_attribute_no_const *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  */
 150 struct 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  */
 172 struct 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  */
 186 extern int extcon_dev_register(struct extcon_dev *edev);
 187 extern void extcon_dev_unregister(struct extcon_dev *edev);
 188 extern int devm_extcon_dev_register(struct device *dev,
 189                                     struct extcon_dev *edev);
 190 extern void devm_extcon_dev_unregister(struct device *dev,
 191                                        struct extcon_dev *edev);
 192 extern struct extcon_dev *extcon_get_extcon_dev(const char *extcon_name);
 193
 194 /*
 195  * Following APIs control the memory of extcon device.
 196  */
 197 extern struct extcon_dev *extcon_dev_allocate(const char **cables);
 198 extern void extcon_dev_free(struct extcon_dev *edev);
 199 extern struct extcon_dev *devm_extcon_dev_allocate(struct device *dev,
 200                                                    const char **cables);
 201 extern 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  */
 209 static inline u32 extcon_get_state(struct extcon_dev *edev)
 210 {
 211         return edev->state;
 212 }
 213
 214 extern int extcon_set_state(struct extcon_dev *edev, u32 state);
 215 extern 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  */
 222 extern int extcon_find_cable_index(struct extcon_dev *sdev,
 223                                    const char *cable_name);
 224 extern int extcon_get_cable_state_(struct extcon_dev *edev, int cable_index);
 225 extern int extcon_set_cable_state_(struct extcon_dev *edev, int cable_index,
 226                                    bool cable_state);
 227
 228 extern int extcon_get_cable_state(struct extcon_dev *edev,
 229                                   const char *cable_name);
 230 extern 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  */
 239 extern 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);
 243 extern 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  */
 252 extern int extcon_register_notifier(struct extcon_dev *edev,
 253                                     struct notifier_block *nb);
 254 extern 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  */
 261 extern struct extcon_dev *extcon_get_edev_by_phandle(struct device *dev, int index);
 262 #else /* CONFIG_EXTCON */
 263 static inline int extcon_dev_register(struct extcon_dev *edev)
 264 {
 265         return 0;
 266 }
 267
 268 static inline void extcon_dev_unregister(struct extcon_dev *edev) { }
 269
 270 static inline int devm_extcon_dev_register(struct device *dev,
 271                                            struct extcon_dev *edev)
 272 {
 273         return -EINVAL;
 274 }
 275
 276 static inline void devm_extcon_dev_unregister(struct device *dev,
 277                                               struct extcon_dev *edev) { }
 278
 279 static inline struct extcon_dev *extcon_dev_allocate(const char **cables)
 280 {
 281         return ERR_PTR(-ENOSYS);
 282 }
 283
 284 static inline void extcon_dev_free(struct extcon_dev *edev) { }
 285
 286 static inline struct extcon_dev *devm_extcon_dev_allocate(struct device *dev,
 287                                                           const char **cables)
 288 {
 289         return ERR_PTR(-ENOSYS);
 290 }
 291
 292 static inline void devm_extcon_dev_free(struct extcon_dev *edev) { }
 293
 294 static inline u32 extcon_get_state(struct extcon_dev *edev)
 295 {
 296         return 0;
 297 }
 298
 299 static inline int extcon_set_state(struct extcon_dev *edev, u32 state)
 300 {
 301         return 0;
 302 }
 303
 304 static inline int extcon_update_state(struct extcon_dev *edev, u32 mask,
 305                                        u32 state)
 306 {
 307         return 0;
 308 }
 309
 310 static inline int extcon_find_cable_index(struct extcon_dev *edev,
 311                                           const char *cable_name)
 312 {
 313         return 0;
 314 }
 315
 316 static inline int extcon_get_cable_state_(struct extcon_dev *edev,
 317                                           int cable_index)
 318 {
 319         return 0;
 320 }
 321
 322 static inline int extcon_set_cable_state_(struct extcon_dev *edev,
 323                                           int cable_index, bool cable_state)
 324 {
 325         return 0;
 326 }
 327
 328 static inline int extcon_get_cable_state(struct extcon_dev *edev,
 329                         const char *cable_name)
 330 {
 331         return 0;
 332 }
 333
 334 static inline int extcon_set_cable_state(struct extcon_dev *edev,
 335                         const char *cable_name, int state)
 336 {
 337         return 0;
 338 }
 339
 340 static inline struct extcon_dev *extcon_get_extcon_dev(const char *extcon_name)
 341 {
 342         return NULL;
 343 }
 344
 345 static inline int extcon_register_notifier(struct extcon_dev *edev,
 346                                            struct notifier_block *nb)
 347 {
 348         return 0;
 349 }
 350
 351 static inline int extcon_unregister_notifier(struct extcon_dev *edev,
 352                                              struct notifier_block *nb)
 353 {
 354         return 0;
 355 }
 356
 357 static 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
 365 static inline int extcon_unregister_interest(struct extcon_specific_cable_nb
 366                                                     *obj)
 367 {
 368         return 0;
 369 }
 370
 371 static 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__ */