drivers/base/component.c

5 #include <linux/component.h>
16  * The component helper allows drivers to collect a pile of sub-devices,
19  * of_clk_get_by_name(). The component helper can be used when such a
20  * subsystem-specific way to find a device is not available: The component
27  * The component helper also doesn't solve runtime dependencies, e.g. for system
33  * Aggregate drivers first assemble a component match list of what they need
39 struct component;
46 	struct component *component;
65 struct component {
98 		struct component *component = match->compare[i].component;
101 			   component ? dev_name(component->dev) : "(unknown)",
102 			   component ? (component->bound ? "bound" : "not bound") : "not registered");
153 static struct component *find_component(struct aggregate_device *adev,
156 	struct component *c;
185 		struct component *c;
187 		dev_dbg(adev->parent, "Looking for component %zu\n", i);
189 		if (match->compare[i].component)
198 		dev_dbg(adev->parent, "found component %s, duplicate %u\n",
201 		/* Attach this component to the adev */
203 		match->compare[i].component = c;
209 /* Detach component from associated aggregate_device */
210 static void remove_component(struct aggregate_device *adev, struct component *c)
214 	/* Detach the component from this adev. */
216 		if (adev->match->compare[i].component == c)
217 			adev->match->compare[i].component = NULL;
221  * Try to bring up an aggregate device.  If component is NULL, we're interested
222  * in this aggregate device, otherwise it's a component which must be present
228 	struct component *component)
239 	if (component && component->adev != adev) {
240 		dev_dbg(adev->parent, "master is not for this component (%s)\n",
241 			dev_name(component->dev));
262 static int try_to_bring_up_masters(struct component *component)
269 			ret = try_to_bring_up_aggregate_device(adev, component);
288  * component_compare_of - A common component compare function for of_node
289  * @dev: component device
303  * component_release_of - A common component release function for of_node
304  * @dev: component device
316  * component_compare_dev - A common component compare function for dev
317  * @dev: component device
330  * component_compare_dev_name - A common component compare function for device name
331  * @dev: component device
421 	match->compare[match->num].component = NULL;
426  * component_match_add_release - add a component match entry with release callback
428  * @matchptr: pointer to the list of component matches
433  * Adds a new component match to the list stored in @matchptr, which the
434  * aggregate driver needs to function. The list of component matches pointed to
456  * component_match_add_typed - add a component match entry for a typed component
458  * @matchptr: pointer to the list of component matches
462  * Adds a new component match to the list stored in @matchptr, which the
463  * aggregate driver needs to function. The list of component matches pointed to
491 			struct component *c = match->compare[i].component;
504  * @match: component match list for the aggregate driver
572 static void component_unbind(struct component *component,
575 	WARN_ON(!component->bound);
577 	if (component->ops && component->ops->unbind)
578 		component->ops->unbind(component->dev, adev->parent, data);
579 	component->bound = false;
581 	/* Release all resources claimed in the binding of this component */
582 	devres_release_group(component->dev, component);
597 	struct component *c;
609 			c = adev->match->compare[i].component;
615 static int component_bind(struct component *component, struct aggregate_device *adev,
621 	 * Each component initialises inside its own devres group.
622 	 * This allows us to roll-back a failed component without
633 	if (!devres_open_group(component->dev, component, GFP_KERNEL)) {
639 		dev_name(component->dev), component->ops);
641 	ret = component->ops->bind(component->dev, adev->parent, data);
643 		component->bound = true;
646 		 * Close the component device's group so that resources
651 		devres_close_group(component->dev, NULL);
655 			 dev_name(component->dev), component->ops);
657 		devres_release_group(component->dev, NULL);
662 				dev_name(component->dev), component->ops, ret);
680 	struct component *c;
693 			c = adev->match->compare[i].component;
702 				c = adev->match->compare[i - 1].component;
714 	struct component *component;
717 	component = kzalloc(sizeof(*component), GFP_KERNEL);
718 	if (!component)
721 	component->ops = ops;
722 	component->dev = dev;
723 	component->subcomponent = subcomponent;
725 	dev_dbg(dev, "adding component (ops %ps)\n", ops);
728 	list_add_tail(&component->node, &component_list);
730 	ret = try_to_bring_up_masters(component);
732 		if (component->adev)
733 			remove_component(component->adev, component);
734 		list_del(&component->node);
736 		kfree(component);
744  * component_add_typed - register a component
745  * @dev: component device
746  * @ops: component callbacks
749  * Register a new component for @dev. Functions in @ops will be call when the
757  * The component needs to be unregistered at driver unload/disconnect by
773  * component_add - register a component
774  * @dev: component device
775  * @ops: component callbacks
777  * Register a new component for @dev. Functions in @ops will be called when the
781  * The component needs to be unregistered at driver unload/disconnect by
794  * component_del - unregister a component
795  * @dev: component device
796  * @ops: component callbacks
798  * Unregister a component added with component_add(). If the component is bound
804 	struct component *c, *component = NULL;
810 			component = c;
814 	if (component && component->adev) {
815 		take_down_aggregate_device(component->adev);
816 		remove_component(component->adev, component);
821 	WARN_ON(!component);
822 	kfree(component);