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Diffstat (limited to 'include/linux/extcon.h')
| -rw-r--r-- | include/linux/extcon.h | 323 |
1 files changed, 323 insertions, 0 deletions
diff --git a/include/linux/extcon.h b/include/linux/extcon.h new file mode 100644 index 000000000000..6495f7731400 --- /dev/null +++ b/include/linux/extcon.h @@ -0,0 +1,323 @@ +/* + * External connector (extcon) class driver + * + * Copyright (C) 2012 Samsung Electronics + * Author: Donggeun Kim <dg77.kim@samsung.com> + * Author: MyungJoo Ham <myungjoo.ham@samsung.com> + * + * based on switch class driver + * Copyright (C) 2008 Google, Inc. + * Author: Mike Lockwood <lockwood@android.com> + * + * This software is licensed under the terms of the GNU General Public + * License version 2, as published by the Free Software Foundation, and + * may be copied, distributed, and modified under those terms. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * +*/ + +#ifndef __LINUX_EXTCON_H__ +#define __LINUX_EXTCON_H__ + +#include <linux/notifier.h> + +#define SUPPORTED_CABLE_MAX 32 +#define CABLE_NAME_MAX 30 + +/* + * The standard cable name is to help support general notifier + * and notifee device drivers to share the common names. + * Please use standard cable names unless your notifier device has + * a very unique and abnormal cable or + * the cable type is supposed to be used with only one unique + * pair of notifier/notifee devices. + * + * Please add any other "standard" cables used with extcon dev. + * + * You may add a dot and number to specify version or specification + * of the specific cable if it is required. (e.g., "Fast-charger.18" + * and "Fast-charger.10" for 1.8A and 1.0A chargers) + * However, the notifee and notifier should be able to handle such + * string and if the notifee can negotiate the protocol or idenify, + * you don't need such convention. This convention is helpful when + * notifier can distinguish but notifiee cannot. + */ +enum extcon_cable_name { + EXTCON_USB = 0, + EXTCON_USB_HOST, + EXTCON_TA, /* Travel Adaptor */ + EXTCON_FAST_CHARGER, + EXTCON_SLOW_CHARGER, + EXTCON_CHARGE_DOWNSTREAM, /* Charging an external device */ + EXTCON_HDMI, + EXTCON_MHL, + EXTCON_DVI, + EXTCON_VGA, + EXTCON_DOCK, + EXTCON_LINE_IN, + EXTCON_LINE_OUT, + EXTCON_MIC_IN, + EXTCON_HEADPHONE_OUT, + EXTCON_SPDIF_IN, + EXTCON_SPDIF_OUT, + EXTCON_VIDEO_IN, + EXTCON_VIDEO_OUT, +}; +extern const char *extcon_cable_name[]; + +struct extcon_cable; + +/** + * struct extcon_dev - An extcon device represents one external connector. + * @name The name of this extcon device. Parent device name is used + * if NULL. + * @supported_cable Array of supported cable name ending with NULL. + * If supported_cable is NULL, cable name related APIs + * are disabled. + * @mutually_exclusive Array of mutually exclusive set of cables that cannot + * be attached simultaneously. The array should be + * ending with NULL or be NULL (no mutually exclusive + * cables). For example, if it is { 0x7, 0x30, 0}, then, + * {0, 1}, {0, 1, 2}, {0, 2}, {1, 2}, or {4, 5} cannot + * be attached simulataneously. {0x7, 0} is equivalent to + * {0x3, 0x6, 0x5, 0}. If it is {0xFFFFFFFF, 0}, there + * can be no simultaneous connections. + * @print_name An optional callback to override the method to print the + * name of the extcon device. + * @print_state An optional callback to override the method to print the + * status of the extcon device. + * @dev Device of this extcon. Do not provide at register-time. + * @state Attach/detach state of this extcon. Do not provide at + * register-time + * @nh Notifier for the state change events from this extcon + * @entry To support list of extcon devices so that uses can search + * for extcon devices based on the extcon name. + * @lock + * @max_supported Internal value to store the number of cables. + * @extcon_dev_type Device_type struct to provide attribute_groups + * customized for each extcon device. + * @cables Sysfs subdirectories. Each represents one cable. + * + * In most cases, users only need to provide "User initializing data" of + * this struct when registering an extcon. In some exceptional cases, + * optional callbacks may be needed. However, the values in "internal data" + * are overwritten by register function. + */ +struct extcon_dev { + /* --- Optional user initializing data --- */ + const char *name; + const char **supported_cable; + const u32 *mutually_exclusive; + + /* --- Optional callbacks to override class functions --- */ + ssize_t (*print_name)(struct extcon_dev *edev, char *buf); + ssize_t (*print_state)(struct extcon_dev *edev, char *buf); + + /* --- Internal data. Please do not set. --- */ + struct device *dev; + u32 state; + struct raw_notifier_head nh; + struct list_head entry; + spinlock_t lock; /* could be called by irq handler */ + int max_supported; + + /* /sys/class/extcon/.../cable.n/... */ + struct device_type extcon_dev_type; + struct extcon_cable *cables; + /* /sys/class/extcon/.../mutually_exclusive/... */ + struct attribute_group attr_g_muex; + struct attribute **attrs_muex; + struct device_attribute *d_attrs_muex; +}; + +/** + * struct extcon_cable - An internal data for each cable of extcon device. + * @edev The extcon device + * @cable_index Index of this cable in the edev + * @attr_g Attribute group for the cable + * @attr_name "name" sysfs entry + * @attr_state "state" sysfs entry + * @attrs Array pointing to attr_name and attr_state for attr_g + */ +struct extcon_cable { + struct extcon_dev *edev; + int cable_index; + + struct attribute_group attr_g; + struct device_attribute attr_name; + struct device_attribute attr_state; + + struct attribute *attrs[3]; /* to be fed to attr_g.attrs */ +}; + +/** + * struct extcon_specific_cable_nb - An internal data for + * extcon_register_interest(). + * @internal_nb a notifier block bridging extcon notifier and cable notifier. + * @user_nb user provided notifier block for events from a specific cable. + * @cable_index the target cable. + * @edev the target extcon device. + * @previous_value the saved previous event value. + */ +struct extcon_specific_cable_nb { + struct notifier_block internal_nb; + struct notifier_block *user_nb; + int cable_index; + struct extcon_dev *edev; + unsigned long previous_value; +}; + +#if IS_ENABLED(CONFIG_EXTCON) + +/* + * Following APIs are for notifiers or configurations. + * Notifiers are the external port and connection devices. + */ +extern int extcon_dev_register(struct extcon_dev *edev, struct device *dev); +extern void extcon_dev_unregister(struct extcon_dev *edev); +extern struct extcon_dev *extcon_get_extcon_dev(const char *extcon_name); + +/* + * get/set/update_state access the 32b encoded state value, which represents + * states of all possible cables of the multistate port. For example, if one + * calls extcon_set_state(edev, 0x7), it may mean that all the three cables + * are attached to the port. + */ +static inline u32 extcon_get_state(struct extcon_dev *edev) +{ + return edev->state; +} + +extern int extcon_set_state(struct extcon_dev *edev, u32 state); +extern int extcon_update_state(struct extcon_dev *edev, u32 mask, u32 state); + +/* + * get/set_cable_state access each bit of the 32b encoded state value. + * They are used to access the status of each cable based on the cable_name + * or cable_index, which is retrived by extcon_find_cable_index + */ +extern int extcon_find_cable_index(struct extcon_dev *sdev, + const char *cable_name); +extern int extcon_get_cable_state_(struct extcon_dev *edev, int cable_index); +extern int extcon_set_cable_state_(struct extcon_dev *edev, int cable_index, + bool cable_state); + +extern int extcon_get_cable_state(struct extcon_dev *edev, + const char *cable_name); +extern int extcon_set_cable_state(struct extcon_dev *edev, + const char *cable_name, bool cable_state); + +/* + * Following APIs are for notifiees (those who want to be notified) + * to register a callback for events from a specific cable of the extcon. + * Notifiees are the connected device drivers wanting to get notified by + * a specific external port of a connection device. + */ +extern int extcon_register_interest(struct extcon_specific_cable_nb *obj, + const char *extcon_name, + const char *cable_name, + struct notifier_block *nb); +extern int extcon_unregister_interest(struct extcon_specific_cable_nb *nb); + +/* + * Following APIs are to monitor every action of a notifier. + * Registerer gets notified for every external port of a connection device. + * Probably this could be used to debug an action of notifier; however, + * we do not recommend to use this at normal 'notifiee' device drivers who + * want to be notified by a specific external port of the notifier. + */ +extern int extcon_register_notifier(struct extcon_dev *edev, + struct notifier_block *nb); +extern int extcon_unregister_notifier(struct extcon_dev *edev, + struct notifier_block *nb); +#else /* CONFIG_EXTCON */ +static inline int extcon_dev_register(struct extcon_dev *edev, + struct device *dev) +{ + return 0; +} + +static inline void extcon_dev_unregister(struct extcon_dev *edev) { } + +static inline u32 extcon_get_state(struct extcon_dev *edev) +{ + return 0; +} + +static inline int extcon_set_state(struct extcon_dev *edev, u32 state) +{ + return 0; +} + +static inline int extcon_update_state(struct extcon_dev *edev, u32 mask, + u32 state) +{ + return 0; +} + +static inline int extcon_find_cable_index(struct extcon_dev *edev, + const char *cable_name) +{ + return 0; +} + +static inline int extcon_get_cable_state_(struct extcon_dev *edev, + int cable_index) +{ + return 0; +} + +static inline int extcon_set_cable_state_(struct extcon_dev *edev, + int cable_index, bool cable_state) +{ + return 0; +} + +static inline int extcon_get_cable_state(struct extcon_dev *edev, + const char *cable_name) +{ + return 0; +} + +static inline int extcon_set_cable_state(struct extcon_dev *edev, + const char *cable_name, int state) +{ + return 0; +} + +static inline struct extcon_dev *extcon_get_extcon_dev(const char *extcon_name) +{ + return NULL; +} + +static inline int extcon_register_notifier(struct extcon_dev *edev, + struct notifier_block *nb) +{ + return 0; +} + +static inline int extcon_unregister_notifier(struct extcon_dev *edev, + struct notifier_block *nb) +{ + return 0; +} + +static inline int extcon_register_interest(struct extcon_specific_cable_nb *obj, + const char *extcon_name, + const char *cable_name, + struct notifier_block *nb) +{ + return 0; +} + +static inline int extcon_unregister_interest(struct extcon_specific_cable_nb + *obj) +{ + return 0; +} +#endif /* CONFIG_EXTCON */ +#endif /* __LINUX_EXTCON_H__ */ |