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	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>
		
			
				
	
	
		
			68 lines
		
	
	
	
		
			2.6 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			68 lines
		
	
	
	
		
			2.6 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
/* SPDX-License-Identifier: GPL-2.0 */
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#ifndef __LINUX_EXTCON_INTERNAL_H__
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#define __LINUX_EXTCON_INTERNAL_H__
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#include <linux/extcon-provider.h>
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/**
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 * struct extcon_dev - An extcon device represents one external connector.
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 * @name:		The name of this extcon device. Parent device name is
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 *			used if NULL.
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 * @supported_cable:	Array of supported cable names ending with EXTCON_NONE.
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 *			If supported_cable is NULL, cable name related APIs
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 *			are disabled.
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 * @mutually_exclusive:	Array of mutually exclusive set of cables that cannot
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 *			be attached simultaneously. The array should be
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 *			ending with 0 or be NULL (no mutually exclusive cables).
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 *			For example, if it is {0x7, 0x30, 0}, then,
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 *			{0, 1}, {0, 1, 2}, {0, 2}, {1, 2}, or {4, 5} cannot
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 *			be attached simulataneously. {0x7, 0} is equivalent to
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 *			{0x3, 0x6, 0x5, 0}. If it is {0xFFFFFFFF, 0}, there
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 *			can be no simultaneous connections.
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 * @dev:		Device of this extcon.
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 * @id:			Unique device ID of this extcon.
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 * @state:		Attach/detach state of this extcon. Do not provide at
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 *			register-time.
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 * @nh_all:		Notifier for the state change events for all supported
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 *			external connectors from this extcon.
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 * @nh:			Notifier for the state change events from this extcon
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 * @entry:		To support list of extcon devices so that users can
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 *			search for extcon devices based on the extcon name.
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 * @lock:		Protects device state and serialises device registration
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 * @max_supported:	Internal value to store the number of cables.
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 * @extcon_dev_type:	Device_type struct to provide attribute_groups
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 *			customized for each extcon device.
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 * @cables:		Sysfs subdirectories. Each represents one cable.
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 *
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 * In most cases, users only need to provide "User initializing data" of
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 * this struct when registering an extcon. In some exceptional cases,
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 * optional callbacks may be needed. However, the values in "internal data"
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 * are overwritten by register function.
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 */
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struct extcon_dev {
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	/* Optional user initializing data */
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	const char *name;
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	const unsigned int *supported_cable;
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	const u32 *mutually_exclusive;
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	/* Internal data. Please do not set. */
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	struct device dev;
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	unsigned int id;
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	struct raw_notifier_head nh_all;
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	struct raw_notifier_head *nh;
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	struct list_head entry;
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	int max_supported;
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	spinlock_t lock;	/* could be called by irq handler */
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	u32 state;
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	/* /sys/class/extcon/.../cable.n/... */
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	struct device_type extcon_dev_type;
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	struct extcon_cable *cables;
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	/* /sys/class/extcon/.../mutually_exclusive/... */
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	struct attribute_group attr_g_muex;
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	struct attribute **attrs_muex;
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	struct device_attribute *d_attrs_muex;
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};
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#endif /* __LINUX_EXTCON_INTERNAL_H__ */
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