/*
* 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 notifiee 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/notifiee 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 notifiee and notifier should be able to handle such
* string and if the notifiee can negotiate the protocol or identify,
* 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,
EXTCON_MECHANICAL,
};
extern const char extcon_cable_name[][CABLE_NAME_MAX + 1];
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 names 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 users 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 retrieved 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.
* Registrar 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 for 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__ */
