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Commit b53a2340 authored by Pantelis Antoniou's avatar Pantelis Antoniou Committed by Grant Likely
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of/reconfig: Add of_reconfig_get_state_change() of notifier helper. 



Introduce of_reconfig_get_state_change() which allows an of notifier
to query about device state changes.

Signed-off-by: default avatarPantelis Antoniou <pantelis.antoniou@konsulko.com>
Signed-off-by: default avatarGrant Likely <grant.likely@linaro.org>
parent da56d04c

drivers/of/dynamic.c

+96 −0
Original line number Diff line number Diff line
@@ -85,6 +85,102 @@ int of_reconfig_notify(unsigned long action, void *p) 
	return notifier_to_errno(rc);

}



/*

 * of_reconfig_get_state_change()	- Returns new state of device

 * @action	- action of the of notifier

 * @arg		- argument of the of notifier

 *

 * Returns the new state of a device based on the notifier used.

 * Returns 0 on device going from enabled to disabled, 1 on device

 * going from disabled to enabled and -1 on no change.

 */

int of_reconfig_get_state_change(unsigned long action, void *arg)

{

	struct device_node *dn;

	struct property *prop, *old_prop;

	struct of_prop_reconfig *pr;

	int is_status, status_state, old_status_state, prev_state, new_state;



	/* figure out if a device should be created or destroyed */

	dn = NULL;

	prop = old_prop = NULL;

	switch (action) {

	case OF_RECONFIG_ATTACH_NODE:

	case OF_RECONFIG_DETACH_NODE:

		dn = arg;

		prop = of_find_property(dn, "status", NULL);

		break;

	case OF_RECONFIG_ADD_PROPERTY:

	case OF_RECONFIG_REMOVE_PROPERTY:

		pr = arg;

		dn = pr->dn;

		prop = pr->prop;

		break;

	case OF_RECONFIG_UPDATE_PROPERTY:

		pr = arg;

		dn = pr->dn;

		prop = pr->prop;

		old_prop = pr->old_prop;

		break;

	default:

		return OF_RECONFIG_NO_CHANGE;

	}



	is_status = 0;

	status_state = -1;

	old_status_state = -1;

	prev_state = -1;

	new_state = -1;



	if (prop && !strcmp(prop->name, "status")) {

		is_status = 1;

		status_state = !strcmp(prop->value, "okay") ||

			       !strcmp(prop->value, "ok");

		if (old_prop)

			old_status_state = !strcmp(old_prop->value, "okay") ||

					   !strcmp(old_prop->value, "ok");

	}



	switch (action) {

	case OF_RECONFIG_ATTACH_NODE:

		prev_state = 0;

		/* -1 & 0 status either missing or okay */

		new_state = status_state != 0;

		break;

	case OF_RECONFIG_DETACH_NODE:

		/* -1 & 0 status either missing or okay */

		prev_state = status_state != 0;

		new_state = 0;

		break;

	case OF_RECONFIG_ADD_PROPERTY:

		if (is_status) {

			/* no status property -> enabled (legacy) */

			prev_state = 1;

			new_state = status_state;

		}

		break;

	case OF_RECONFIG_REMOVE_PROPERTY:

		if (is_status) {

			prev_state = status_state;

			/* no status property -> enabled (legacy) */

			new_state = 1;

		}

		break;

	case OF_RECONFIG_UPDATE_PROPERTY:

		if (is_status) {

			prev_state = old_status_state != 0;

			new_state = status_state != 0;

		}

		break;

	}



	if (prev_state == new_state)

		return OF_RECONFIG_NO_CHANGE;



	return new_state ? OF_RECONFIG_CHANGE_ADD : OF_RECONFIG_CHANGE_REMOVE;

}

EXPORT_SYMBOL_GPL(of_reconfig_get_state_change);



int of_property_notify(int action, struct device_node *np,

		       struct property *prop, struct property *oldprop)

{

include/linux/of.h

+7 −0
Original line number Diff line number Diff line
@@ -327,6 +327,7 @@ struct of_prop_reconfig { 
extern int of_reconfig_notifier_register(struct notifier_block *);

extern int of_reconfig_notifier_unregister(struct notifier_block *);

extern int of_reconfig_notify(unsigned long, void *);

extern int of_reconfig_get_state_change(unsigned long action, void *arg);



extern int of_attach_node(struct device_node *);

extern int of_detach_node(struct device_node *);
@@ -887,6 +888,12 @@ struct of_changeset { 
	struct list_head entries;

};



enum of_reconfig_change {

	OF_RECONFIG_NO_CHANGE = 0,

	OF_RECONFIG_CHANGE_ADD,

	OF_RECONFIG_CHANGE_REMOVE,

};



#ifdef CONFIG_OF_DYNAMIC

extern void of_changeset_init(struct of_changeset *ocs);

extern void of_changeset_destroy(struct of_changeset *ocs);