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Commit 046050f6 authored by Chanwoo Choi's avatar Chanwoo Choi
Browse files

extcon: Update the prototype of extcon_register_notifier() with enum extcon 



Previously, extcon consumer driver used the extcon_register_interest()
to register the notifier chain and then to receive the notifier event
when external connector's state is changed. When registering the notifier chain
for specific external connector with extcon_register_interest(), it used the
the string name of external connector directly. There are potential problem
because of unclear, non-standard and inconsequent cable name. Namely,
it is not appropriate method to identify each external connector.

So, this patch modify the prototype of extcon_register_notifier() by using
the 'enum extcon' which are the unique id for each external connector
instead of unclear string method.

- Previously, the extcon consumer driver used the extcon_register_interest()
with 'cable_name' to point out the specific external connector. Also. it used
the un-needed structure (struct extcon_specific_cable_nb).
: int extcon_register_interest(struct extcon_specific_cable_nb *obj,
			     const char *extcon_name, const char *cable_name,
			     struct notifier_block *nb)

- Newly, the updated extcon_register_notifier() would definitely support
the same feature to detech the changed state of external connector without
any specific structure (struct extcon_specific_cable_nb).
: int extcon_register_notifier(struct extcon_dev *edev, enum extcon id,
			     struct notifier_block *nb)

This patch support the both extcon_register_interest() and new extcon_register_
notifier(). But the extcon_{register|unregister}_interest() will be deprecated
because extcon core would support the notifier event for extcon consumer driver
with only updated extcon_register_notifier() and 'extcon_specific_cable_nb'
will be removed if there are no extcon consumer driver with legacy
extcon_{register|unregister}_interest().

Signed-off-by: default avatarChanwoo Choi <cw00.choi@samsung.com>
Reviewed-by: default avatarKrzysztof Kozlowski <k.kozlowski@samsung.com>
parent 8e9bc36d

drivers/extcon/extcon.c

+48 −43
Original line number Diff line number Diff line
@@ -146,6 +146,16 @@ static int find_cable_index_by_name(struct extcon_dev *edev, const char *name) 
	return find_cable_index_by_id(edev, id);

}



static bool is_extcon_changed(u32 prev, u32 new, int idx, bool *attached)

{

	if (((prev >> idx) & 0x1) != ((new >> idx) & 0x1)) {

		*attached = new ? true : false;

		return true;

	}



	return false;

}



static ssize_t state_show(struct device *dev, struct device_attribute *attr,

			  char *buf)

{
@@ -254,23 +264,27 @@ int extcon_update_state(struct extcon_dev *edev, u32 mask, u32 state) 
	char *envp[3];

	int env_offset = 0;

	int length;

	int index;

	unsigned long flags;

	bool attached;



	spin_lock_irqsave(&edev->lock, flags);



	if (edev->state != ((edev->state & ~mask) | (state & mask))) {

		u32 old_state = edev->state;



		if (check_mutually_exclusive(edev, (edev->state & ~mask) |

						   (state & mask))) {

			spin_unlock_irqrestore(&edev->lock, flags);

			return -EPERM;

		}



		for (index = 0; index < edev->max_supported; index++) {

			if (is_extcon_changed(edev->state, state, index, &attached))

				raw_notifier_call_chain(&edev->nh[index], attached, edev);

		}



		edev->state &= ~mask;

		edev->state |= state & mask;



		raw_notifier_call_chain(&edev->nh, old_state, edev);

		/* This could be in interrupt handler */

		prop_buf = (char *)get_zeroed_page(GFP_ATOMIC);

		if (prop_buf) {
@@ -423,29 +437,6 @@ out: 
}

EXPORT_SYMBOL_GPL(extcon_get_extcon_dev);



static int _call_per_cable(struct notifier_block *nb, unsigned long val,

			   void *ptr)

{

	struct extcon_specific_cable_nb *obj = container_of(nb,

			struct extcon_specific_cable_nb, internal_nb);

	struct extcon_dev *edev = ptr;



	if ((val & (1 << obj->cable_index)) !=

	    (edev->state & (1 << obj->cable_index))) {

		bool cable_state = true;



		obj->previous_value = val;



		if (val & (1 << obj->cable_index))

			cable_state = false;



		return obj->user_nb->notifier_call(obj->user_nb,

				cable_state, ptr);

	}



	return NOTIFY_OK;

}



/**

 * extcon_register_interest() - Register a notifier for a state change of a

 *				specific cable, not an entier set of cables of a
@@ -491,11 +482,10 @@ int extcon_register_interest(struct extcon_specific_cable_nb *obj, 


		obj->user_nb = nb;



		obj->internal_nb.notifier_call = _call_per_cable;



		spin_lock_irqsave(&obj->edev->lock, flags);

		ret = raw_notifier_chain_register(&obj->edev->nh,

						  &obj->internal_nb);

		ret = raw_notifier_chain_register(

					&obj->edev->nh[obj->cable_index],

					obj->user_nb);

		spin_unlock_irqrestore(&obj->edev->lock, flags);

	} else {

		struct class_dev_iter iter;
@@ -538,7 +528,8 @@ int extcon_unregister_interest(struct extcon_specific_cable_nb *obj) 
		return -EINVAL;



	spin_lock_irqsave(&obj->edev->lock, flags);

	ret = raw_notifier_chain_unregister(&obj->edev->nh, &obj->internal_nb);

	ret = raw_notifier_chain_unregister(

			&obj->edev->nh[obj->cable_index], obj->user_nb);

	spin_unlock_irqrestore(&obj->edev->lock, flags);



	return ret;
@@ -548,21 +539,24 @@ EXPORT_SYMBOL_GPL(extcon_unregister_interest); 
/**

 * extcon_register_notifier() - Register a notifiee to get notified by

 *				any attach status changes from the extcon.

 * @edev:	the extcon device.

 * @edev:	the extcon device that has the external connecotr.

 * @id:		the unique id of each external connector in extcon enumeration.

 * @nb:		a notifier block to be registered.

 *

 * Note that the second parameter given to the callback of nb (val) is

 * "old_state", not the current state. The current state can be retrieved

 * by looking at the third pameter (edev pointer)'s state value.

 */

int extcon_register_notifier(struct extcon_dev *edev,

int extcon_register_notifier(struct extcon_dev *edev, enum extcon id,

			     struct notifier_block *nb)

{

	unsigned long flags;

	int ret;

	int ret, idx;



	idx = find_cable_index_by_id(edev, id);



	spin_lock_irqsave(&edev->lock, flags);

	ret = raw_notifier_chain_register(&edev->nh, nb);

	ret = raw_notifier_chain_register(&edev->nh[idx], nb);

	spin_unlock_irqrestore(&edev->lock, flags);



	return ret;
@@ -571,17 +565,20 @@ EXPORT_SYMBOL_GPL(extcon_register_notifier); 


/**

 * extcon_unregister_notifier() - Unregister a notifiee from the extcon device.

 * @edev:	the extcon device.

 * @nb:		a registered notifier block to be unregistered.

 * @edev:	the extcon device that has the external connecotr.

 * @id:		the unique id of each external connector in extcon enumeration.

 * @nb:		a notifier block to be registered.

 */

int extcon_unregister_notifier(struct extcon_dev *edev,

int extcon_unregister_notifier(struct extcon_dev *edev, enum extcon id,

				struct notifier_block *nb)

{

	unsigned long flags;

	int ret;

	int ret, idx;



	idx = find_cable_index_by_id(edev, id);



	spin_lock_irqsave(&edev->lock, flags);

	ret = raw_notifier_chain_unregister(&edev->nh, nb);

	ret = raw_notifier_chain_unregister(&edev->nh[idx], nb);

	spin_unlock_irqrestore(&edev->lock, flags);



	return ret;
@@ -893,7 +890,15 @@ int extcon_dev_register(struct extcon_dev *edev) 


	spin_lock_init(&edev->lock);



	RAW_INIT_NOTIFIER_HEAD(&edev->nh);

	edev->nh = devm_kzalloc(&edev->dev,

			sizeof(*edev->nh) * edev->max_supported, GFP_KERNEL);

	if (!edev->nh) {

		ret = -ENOMEM;

		goto err_dev;

	}



	for (index = 0; index < edev->max_supported; index++)

		RAW_INIT_NOTIFIER_HEAD(&edev->nh[index]);



	dev_set_drvdata(&edev->dev, edev);

	edev->state = 0;

include/linux/extcon.h

+8 −9
Original line number Diff line number Diff line
@@ -116,7 +116,7 @@ struct extcon_dev { 


	/* Internal data. Please do not set. */

	struct device dev;

	struct raw_notifier_head nh;

	struct raw_notifier_head *nh;

	struct list_head entry;

	int max_supported;

	spinlock_t lock;	/* could be called by irq handler */
@@ -155,8 +155,6 @@ struct extcon_cable { 
/**

 * 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.
@@ -164,7 +162,6 @@ struct extcon_cable { 
 * @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;
@@ -240,9 +237,9 @@ extern int extcon_unregister_interest(struct extcon_specific_cable_nb *nb); 
 * 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,

extern int extcon_register_notifier(struct extcon_dev *edev, enum extcon id,

				    struct notifier_block *nb);

extern int extcon_unregister_notifier(struct extcon_dev *edev,

extern int extcon_unregister_notifier(struct extcon_dev *edev, enum extcon id,

				    struct notifier_block *nb);



/*
@@ -333,12 +330,14 @@ static inline struct extcon_dev *extcon_get_extcon_dev(const char *extcon_name) 
}



static inline int extcon_register_notifier(struct extcon_dev *edev,

					enum extcon id,

					struct notifier_block *nb)

{

	return 0;

}



static inline int extcon_unregister_notifier(struct extcon_dev *edev,

					enum extcon id,

					struct notifier_block *nb)

{

	return 0;