linux/drivers/extcon/extcon.h
Andy Shevchenko 7bba9e81a6 extcon: Use unique number for the extcon device ID
The use of atomic variable is still racy when we do not control which
device has been unregistered and there is a (theoretical) possibility
of the overflow that may cause a duplicate extcon device ID number
to be allocated next time a device is registered.

Replace above mentioned approach by using IDA framework.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
2023-05-29 23:41:29 +09:00

69 lines
2.6 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef __LINUX_EXTCON_INTERNAL_H__
#define __LINUX_EXTCON_INTERNAL_H__
#include <linux/extcon-provider.h>
/**
* 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 EXTCON_NONE.
* 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 0 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.
* @dev: Device of this extcon.
* @id: Unique device ID of this extcon.
* @state: Attach/detach state of this extcon. Do not provide at
* register-time.
* @nh_all: Notifier for the state change events for all supported
* external connectors from this extcon.
* @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: Protects device state and serialises device registration
* @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 unsigned int *supported_cable;
const u32 *mutually_exclusive;
/* Internal data. Please do not set. */
struct device dev;
unsigned int id;
struct raw_notifier_head nh_all;
struct raw_notifier_head *nh;
struct list_head entry;
int max_supported;
spinlock_t lock; /* could be called by irq handler */
u32 state;
/* /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;
};
#endif /* __LINUX_EXTCON_INTERNAL_H__ */