[linux-2.6-block.git] / drivers / base / component.c

/*
 * Componentized device handling.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 * This is work in progress.  We gather up the component devices into a list,
 * and bind them when instructed.  At the moment, we're specific to the DRM
 * subsystem, and only handles one master device, but this doesn't have to be
 * the case.
 */
#include <linux/component.h>
#include <linux/device.h>
#include <linux/kref.h>
#include <linux/list.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/slab.h>

struct component_match {
	size_t alloc;
	size_t num;
	struct {
		void *data;
		int (*fn)(struct device *, void *);
	} compare[0];
};

struct master {
	struct list_head node;
	struct list_head components;
	bool bound;

	const struct component_master_ops *ops;
	struct device *dev;
	struct component_match *match;
};

struct component {
	struct list_head node;
	struct list_head master_node;
	struct master *master;
	bool bound;

	const struct component_ops *ops;
	struct device *dev;
};

static DEFINE_MUTEX(component_mutex);
static LIST_HEAD(component_list);
static LIST_HEAD(masters);

static struct master *__master_find(struct device *dev,
	const struct component_master_ops *ops)
{
	struct master *m;

	list_for_each_entry(m, &masters, node)
		if (m->dev == dev && (!ops || m->ops == ops))
			return m;

	return NULL;
}

/* Attach an unattached component to a master. */
static void component_attach_master(struct master *master, struct component *c)
{
	c->master = master;

	list_add_tail(&c->master_node, &master->components);
}

/* Detach a component from a master. */
static void component_detach_master(struct master *master, struct component *c)
{
	list_del(&c->master_node);

	c->master = NULL;
}

/*
 * Add a component to a master, finding the component via the compare
 * function and compare data.  This is safe to call for duplicate matches
 * and will not result in the same component being added multiple times.
 */
int component_master_add_child(struct master *master,
	int (*compare)(struct device *, void *), void *compare_data)
{
	struct component *c;
	int ret = -ENXIO;

	list_for_each_entry(c, &component_list, node) {
		if (c->master && c->master != master)
			continue;

		if (compare(c->dev, compare_data)) {
			if (!c->master)
				component_attach_master(master, c);
			ret = 0;
			break;
		}
	}

	return ret;
}
EXPORT_SYMBOL_GPL(component_master_add_child);

static int find_components(struct master *master)
{
	struct component_match *match = master->match;
	size_t i;
	int ret = 0;

	if (!match) {
		/*
		 * Search the list of components, looking for components that
		 * belong to this master, and attach them to the master.
		 */
		return master->ops->add_components(master->dev, master);
	}

	/*
	 * Scan the array of match functions and attach
	 * any components which are found to this master.
	 */
	for (i = 0; i < match->num; i++) {
		ret = component_master_add_child(master,
						 match->compare[i].fn,
						 match->compare[i].data);
		if (ret)
			break;
	}
	return ret;
}

/* Detach all attached components from this master */
static void master_remove_components(struct master *master)
{
	while (!list_empty(&master->components)) {
		struct component *c = list_first_entry(&master->components,
					struct component, master_node);

		WARN_ON(c->master != master);

		component_detach_master(master, c);
	}
}

/*
 * Try to bring up a master.  If component is NULL, we're interested in
 * this master, otherwise it's a component which must be present to try
 * and bring up the master.
 *
 * Returns 1 for successful bringup, 0 if not ready, or -ve errno.
 */
static int try_to_bring_up_master(struct master *master,
	struct component *component)
{
	int ret;

	if (master->bound)
		return 0;

	/*
	 * Search the list of components, looking for components that
	 * belong to this master, and attach them to the master.
	 */
	if (find_components(master)) {
		/* Failed to find all components */
		ret = 0;
		goto out;
	}

	if (component && component->master != master) {
		ret = 0;
		goto out;
	}

	if (!devres_open_group(master->dev, NULL, GFP_KERNEL)) {
		ret = -ENOMEM;
		goto out;
	}

	/* Found all components */
	ret = master->ops->bind(master->dev);
	if (ret < 0) {
		devres_release_group(master->dev, NULL);
		dev_info(master->dev, "master bind failed: %d\n", ret);
		goto out;
	}

	master->bound = true;
	return 1;

out:
	master_remove_components(master);

	return ret;
}

static int try_to_bring_up_masters(struct component *component)
{
	struct master *m;
	int ret = 0;

	list_for_each_entry(m, &masters, node) {
		ret = try_to_bring_up_master(m, component);
		if (ret != 0)
			break;
	}

	return ret;
}

static void take_down_master(struct master *master)
{
	if (master->bound) {
		master->ops->unbind(master->dev);
		devres_release_group(master->dev, NULL);
		master->bound = false;
	}

	master_remove_components(master);
}

static size_t component_match_size(size_t num)
{
	return offsetof(struct component_match, compare[num]);
}

static struct component_match *component_match_realloc(struct device *dev,
	struct component_match *match, size_t num)
{
	struct component_match *new;

	if (match && match->alloc == num)
		return match;

	new = devm_kmalloc(dev, component_match_size(num), GFP_KERNEL);
	if (!new)
		return ERR_PTR(-ENOMEM);

	if (match) {
		memcpy(new, match, component_match_size(min(match->num, num)));
		devm_kfree(dev, match);
	} else {
		new->num = 0;
	}

	new->alloc = num;

	return new;
}

/*
 * Add a component to be matched.
 *
 * The match array is first created or extended if necessary.
 */
void component_match_add(struct device *dev, struct component_match **matchptr,
	int (*compare)(struct device *, void *), void *compare_data)
{
	struct component_match *match = *matchptr;

	if (IS_ERR(match))
		return;

	if (!match || match->num == match->alloc) {
		size_t new_size = match ? match->alloc + 16 : 15;

		match = component_match_realloc(dev, match, new_size);

		*matchptr = match;

		if (IS_ERR(match))
			return;
	}

	match->compare[match->num].fn = compare;
	match->compare[match->num].data = compare_data;
	match->num++;
}
EXPORT_SYMBOL(component_match_add);

int component_master_add_with_match(struct device *dev,
	const struct component_master_ops *ops,
	struct component_match *match)
{
	struct master *master;
	int ret;

	if (ops->add_components && match)
		return -EINVAL;

	if (match) {
		/* Reallocate the match array for its true size */
		match = component_match_realloc(dev, match, match->num);
		if (IS_ERR(match))
			return PTR_ERR(match);
	}

	master = kzalloc(sizeof(*master), GFP_KERNEL);
	if (!master)
		return -ENOMEM;

	master->dev = dev;
	master->ops = ops;
	master->match = match;
	INIT_LIST_HEAD(&master->components);

	/* Add to the list of available masters. */
	mutex_lock(&component_mutex);
	list_add(&master->node, &masters);

	ret = try_to_bring_up_master(master, NULL);

	if (ret < 0) {
		/* Delete off the list if we weren't successful */
		list_del(&master->node);
		kfree(master);
	}
	mutex_unlock(&component_mutex);

	return ret < 0 ? ret : 0;
}
EXPORT_SYMBOL_GPL(component_master_add_with_match);

int component_master_add(struct device *dev,
	const struct component_master_ops *ops)
{
	return component_master_add_with_match(dev, ops, NULL);
}
EXPORT_SYMBOL_GPL(component_master_add);

void component_master_del(struct device *dev,
	const struct component_master_ops *ops)
{
	struct master *master;

	mutex_lock(&component_mutex);
	master = __master_find(dev, ops);
	if (master) {
		take_down_master(master);

		list_del(&master->node);
		kfree(master);
	}
	mutex_unlock(&component_mutex);
}
EXPORT_SYMBOL_GPL(component_master_del);

static void component_unbind(struct component *component,
	struct master *master, void *data)
{
	WARN_ON(!component->bound);

	component->ops->unbind(component->dev, master->dev, data);
	component->bound = false;

	/* Release all resources claimed in the binding of this component */
	devres_release_group(component->dev, component);
}

void component_unbind_all(struct device *master_dev, void *data)
{
	struct master *master;
	struct component *c;

	WARN_ON(!mutex_is_locked(&component_mutex));

	master = __master_find(master_dev, NULL);
	if (!master)
		return;

	list_for_each_entry_reverse(c, &master->components, master_node)
		component_unbind(c, master, data);
}
EXPORT_SYMBOL_GPL(component_unbind_all);

static int component_bind(struct component *component, struct master *master,
	void *data)
{
	int ret;

	/*
	 * Each component initialises inside its own devres group.
	 * This allows us to roll-back a failed component without
	 * affecting anything else.
	 */
	if (!devres_open_group(master->dev, NULL, GFP_KERNEL))
		return -ENOMEM;

	/*
	 * Also open a group for the device itself: this allows us
	 * to release the resources claimed against the sub-device
	 * at the appropriate moment.
	 */
	if (!devres_open_group(component->dev, component, GFP_KERNEL)) {
		devres_release_group(master->dev, NULL);
		return -ENOMEM;
	}

	dev_dbg(master->dev, "binding %s (ops %ps)\n",
		dev_name(component->dev), component->ops);

	ret = component->ops->bind(component->dev, master->dev, data);
	if (!ret) {
		component->bound = true;

		/*
		 * Close the component device's group so that resources
		 * allocated in the binding are encapsulated for removal
		 * at unbind.  Remove the group on the DRM device as we
		 * can clean those resources up independently.
		 */
		devres_close_group(component->dev, NULL);
		devres_remove_group(master->dev, NULL);

		dev_info(master->dev, "bound %s (ops %ps)\n",
			 dev_name(component->dev), component->ops);
	} else {
		devres_release_group(component->dev, NULL);
		devres_release_group(master->dev, NULL);

		dev_err(master->dev, "failed to bind %s (ops %ps): %d\n",
			dev_name(component->dev), component->ops, ret);
	}

	return ret;
}

int component_bind_all(struct device *master_dev, void *data)
{
	struct master *master;
	struct component *c;
	int ret = 0;

	WARN_ON(!mutex_is_locked(&component_mutex));

	master = __master_find(master_dev, NULL);
	if (!master)
		return -EINVAL;

	list_for_each_entry(c, &master->components, master_node) {
		ret = component_bind(c, master, data);
		if (ret)
			break;
	}

	if (ret != 0) {
		list_for_each_entry_continue_reverse(c, &master->components,
						     master_node)
			component_unbind(c, master, data);
	}

	return ret;
}
EXPORT_SYMBOL_GPL(component_bind_all);

int component_add(struct device *dev, const struct component_ops *ops)
{
	struct component *component;
	int ret;

	component = kzalloc(sizeof(*component), GFP_KERNEL);
	if (!component)
		return -ENOMEM;

	component->ops = ops;
	component->dev = dev;

	dev_dbg(dev, "adding component (ops %ps)\n", ops);

	mutex_lock(&component_mutex);
	list_add_tail(&component->node, &component_list);

	ret = try_to_bring_up_masters(component);
	if (ret < 0) {
		list_del(&component->node);

		kfree(component);
	}
	mutex_unlock(&component_mutex);

	return ret < 0 ? ret : 0;
}
EXPORT_SYMBOL_GPL(component_add);

void component_del(struct device *dev, const struct component_ops *ops)
{
	struct component *c, *component = NULL;

	mutex_lock(&component_mutex);
	list_for_each_entry(c, &component_list, node)
		if (c->dev == dev && c->ops == ops) {
			list_del(&c->node);
			component = c;
			break;
		}

	if (component && component->master)
		take_down_master(component->master);

	mutex_unlock(&component_mutex);

	WARN_ON(!component);
	kfree(component);
}
EXPORT_SYMBOL_GPL(component_del);

MODULE_LICENSE("GPL v2");
Commit	Line	Data
2a41e607 RK	1	/*
	2	* Componentized device handling.
	3	*
	4	* This program is free software; you can redistribute it and/or modify
	5	* it under the terms of the GNU General Public License version 2 as
	6	* published by the Free Software Foundation.
	7	*
	8	* This is work in progress. We gather up the component devices into a list,
	9	* and bind them when instructed. At the moment, we're specific to the DRM
	10	* subsystem, and only handles one master device, but this doesn't have to be
	11	* the case.
	12	*/
	13	#include <linux/component.h>
	14	#include <linux/device.h>
	15	#include <linux/kref.h>
	16	#include <linux/list.h>
	17	#include <linux/module.h>
	18	#include <linux/mutex.h>
	19	#include <linux/slab.h>
	20
6955b582 RK	21	struct component_match {
	22	size_t alloc;
	23	size_t num;
	24	struct {
	25	void *data;
	26	int (fn)(struct device , void *);
	27	} compare[0];
	28	};
	29
2a41e607 RK	30	struct master {
	31	struct list_head node;
	32	struct list_head components;
	33	bool bound;
	34
	35	const struct component_master_ops *ops;
	36	struct device *dev;
6955b582	37	struct component_match *match;
2a41e607 RK	38	};
	39
	40	struct component {
	41	struct list_head node;
	42	struct list_head master_node;
	43	struct master *master;
	44	bool bound;
	45
	46	const struct component_ops *ops;
	47	struct device *dev;
	48	};
	49
	50	static DEFINE_MUTEX(component_mutex);
	51	static LIST_HEAD(component_list);
	52	static LIST_HEAD(masters);
	53
	54	static struct master __master_find(struct device dev,
	55	const struct component_master_ops *ops)
	56	{
	57	struct master *m;
	58
	59	list_for_each_entry(m, &masters, node)
	60	if (m->dev == dev && (!ops \|\| m->ops == ops))
	61	return m;
	62
	63	return NULL;
	64	}
	65
	66	/* Attach an unattached component to a master. */
	67	static void component_attach_master(struct master master, struct component c)
	68	{
	69	c->master = master;
	70
	71	list_add_tail(&c->master_node, &master->components);
	72	}
	73
	74	/* Detach a component from a master. */
	75	static void component_detach_master(struct master master, struct component c)
	76	{
	77	list_del(&c->master_node);
	78
	79	c->master = NULL;
	80	}
	81
fcbcebce RK	82	/*
	83	* Add a component to a master, finding the component via the compare
	84	* function and compare data. This is safe to call for duplicate matches
	85	* and will not result in the same component being added multiple times.
	86	*/
2a41e607 RK	87	int component_master_add_child(struct master *master,
	88	int (compare)(struct device , void ), void compare_data)
	89	{
	90	struct component *c;
	91	int ret = -ENXIO;
	92
	93	list_for_each_entry(c, &component_list, node) {
fcbcebce	94	if (c->master && c->master != master)
2a41e607 RK	95	continue;
	96
	97	if (compare(c->dev, compare_data)) {
fcbcebce RK	98	if (!c->master)
fcbcebce RK	99	component_attach_master(master, c);
2a41e607 RK	100	ret = 0;
	101	break;
	102	}
	103	}
	104
	105	return ret;
	106	}
	107	EXPORT_SYMBOL_GPL(component_master_add_child);
	108
6955b582 RK	109	static int find_components(struct master *master)
	110	{
	111	struct component_match *match = master->match;
	112	size_t i;
	113	int ret = 0;
	114
	115	if (!match) {
	116	/*
	117	* Search the list of components, looking for components that
	118	* belong to this master, and attach them to the master.
	119	*/
	120	return master->ops->add_components(master->dev, master);
	121	}
	122
	123	/*
	124	* Scan the array of match functions and attach
	125	* any components which are found to this master.
	126	*/
	127	for (i = 0; i < match->num; i++) {
	128	ret = component_master_add_child(master,
	129	match->compare[i].fn,
	130	match->compare[i].data);
	131	if (ret)
	132	break;
	133	}
	134	return ret;
	135	}
	136
2a41e607 RK	137	/* Detach all attached components from this master */
	138	static void master_remove_components(struct master *master)
	139	{
	140	while (!list_empty(&master->components)) {
	141	struct component *c = list_first_entry(&master->components,
	142	struct component, master_node);
	143
	144	WARN_ON(c->master != master);
	145
	146	component_detach_master(master, c);
	147	}
	148	}
	149
	150	/*
	151	* Try to bring up a master. If component is NULL, we're interested in
	152	* this master, otherwise it's a component which must be present to try
	153	* and bring up the master.
	154	*
	155	* Returns 1 for successful bringup, 0 if not ready, or -ve errno.
	156	*/
	157	static int try_to_bring_up_master(struct master *master,
	158	struct component *component)
	159	{
c334940e RK	160	int ret;
	161
	162	if (master->bound)
	163	return 0;
	164
	165	/*
	166	* Search the list of components, looking for components that
	167	* belong to this master, and attach them to the master.
	168	*/
6955b582	169	if (find_components(master)) {
c334940e RK	170	/* Failed to find all components */
	171	ret = 0;
	172	goto out;
	173	}
2a41e607	174
c334940e RK	175	if (component && component->master != master) {
	176	ret = 0;
	177	goto out;
	178	}
2a41e607	179
c334940e RK	180	if (!devres_open_group(master->dev, NULL, GFP_KERNEL)) {
	181	ret = -ENOMEM;
	182	goto out;
	183	}
2a41e607	184
c334940e RK	185	/* Found all components */
	186	ret = master->ops->bind(master->dev);
	187	if (ret < 0) {
	188	devres_release_group(master->dev, NULL);
	189	dev_info(master->dev, "master bind failed: %d\n", ret);
	190	goto out;
	191	}
9e1ccb4a	192
c334940e RK	193	master->bound = true;
c334940e RK	194	return 1;
2a41e607	195
2a41e607	196	out:
c334940e	197	master_remove_components(master);
2a41e607 RK	198
	199	return ret;
	200	}
	201
	202	static int try_to_bring_up_masters(struct component *component)
	203	{
	204	struct master *m;
	205	int ret = 0;
	206
	207	list_for_each_entry(m, &masters, node) {
	208	ret = try_to_bring_up_master(m, component);
	209	if (ret != 0)
	210	break;
	211	}
	212
	213	return ret;
	214	}
	215
	216	static void take_down_master(struct master *master)
	217	{
	218	if (master->bound) {
	219	master->ops->unbind(master->dev);
9e1ccb4a	220	devres_release_group(master->dev, NULL);
2a41e607 RK	221	master->bound = false;
	222	}
	223
	224	master_remove_components(master);
	225	}
	226
6955b582 RK	227	static size_t component_match_size(size_t num)
	228	{
	229	return offsetof(struct component_match, compare[num]);
	230	}
	231
	232	static struct component_match component_match_realloc(struct device dev,
	233	struct component_match *match, size_t num)
	234	{
	235	struct component_match *new;
	236
	237	if (match && match->alloc == num)
	238	return match;
	239
	240	new = devm_kmalloc(dev, component_match_size(num), GFP_KERNEL);
	241	if (!new)
	242	return ERR_PTR(-ENOMEM);
	243
	244	if (match) {
	245	memcpy(new, match, component_match_size(min(match->num, num)));
	246	devm_kfree(dev, match);
	247	} else {
	248	new->num = 0;
	249	}
	250
	251	new->alloc = num;
	252
	253	return new;
	254	}
	255
	256	/*
	257	* Add a component to be matched.
	258	*
	259	* The match array is first created or extended if necessary.
	260	*/
	261	void component_match_add(struct device dev, struct component_match *matchptr,
	262	int (compare)(struct device , void ), void compare_data)
	263	{
	264	struct component_match match = matchptr;
	265
	266	if (IS_ERR(match))
	267	return;
	268
	269	if (!match \|\| match->num == match->alloc) {
	270	size_t new_size = match ? match->alloc + 16 : 15;
	271
	272	match = component_match_realloc(dev, match, new_size);
	273
	274	*matchptr = match;
	275
	276	if (IS_ERR(match))
	277	return;
	278	}
	279
	280	match->compare[match->num].fn = compare;
	281	match->compare[match->num].data = compare_data;
	282	match->num++;
	283	}
	284	EXPORT_SYMBOL(component_match_add);
	285
	286	int component_master_add_with_match(struct device *dev,
	287	const struct component_master_ops *ops,
	288	struct component_match *match)
2a41e607 RK	289	{
	290	struct master *master;
	291	int ret;
	292
6955b582 RK	293	if (ops->add_components && match)
	294	return -EINVAL;
	295
b509cc80 RK	296	if (match) {
	297	/* Reallocate the match array for its true size */
	298	match = component_match_realloc(dev, match, match->num);
	299	if (IS_ERR(match))
	300	return PTR_ERR(match);
	301	}
6955b582	302
2a41e607 RK	303	master = kzalloc(sizeof(*master), GFP_KERNEL);
	304	if (!master)
	305	return -ENOMEM;
	306
	307	master->dev = dev;
	308	master->ops = ops;
6955b582	309	master->match = match;
2a41e607 RK	310	INIT_LIST_HEAD(&master->components);
	311
	312	/* Add to the list of available masters. */
	313	mutex_lock(&component_mutex);
	314	list_add(&master->node, &masters);
	315
	316	ret = try_to_bring_up_master(master, NULL);
	317
	318	if (ret < 0) {
	319	/* Delete off the list if we weren't successful */
	320	list_del(&master->node);
	321	kfree(master);
	322	}
	323	mutex_unlock(&component_mutex);
	324
	325	return ret < 0 ? ret : 0;
	326	}
6955b582 RK	327	EXPORT_SYMBOL_GPL(component_master_add_with_match);
	328
	329	int component_master_add(struct device *dev,
	330	const struct component_master_ops *ops)
	331	{
	332	return component_master_add_with_match(dev, ops, NULL);
	333	}
2a41e607 RK	334	EXPORT_SYMBOL_GPL(component_master_add);
	335
	336	void component_master_del(struct device *dev,
	337	const struct component_master_ops *ops)
	338	{
	339	struct master *master;
	340
	341	mutex_lock(&component_mutex);
	342	master = __master_find(dev, ops);
	343	if (master) {
	344	take_down_master(master);
	345
	346	list_del(&master->node);
	347	kfree(master);
	348	}
	349	mutex_unlock(&component_mutex);
	350	}
	351	EXPORT_SYMBOL_GPL(component_master_del);
	352
	353	static void component_unbind(struct component *component,
	354	struct master master, void data)
	355	{
	356	WARN_ON(!component->bound);
	357
	358	component->ops->unbind(component->dev, master->dev, data);
	359	component->bound = false;
	360
	361	/* Release all resources claimed in the binding of this component */
	362	devres_release_group(component->dev, component);
	363	}
	364
	365	void component_unbind_all(struct device master_dev, void data)
	366	{
	367	struct master *master;
	368	struct component *c;
	369
	370	WARN_ON(!mutex_is_locked(&component_mutex));
	371
	372	master = __master_find(master_dev, NULL);
	373	if (!master)
	374	return;
	375
	376	list_for_each_entry_reverse(c, &master->components, master_node)
	377	component_unbind(c, master, data);
	378	}
	379	EXPORT_SYMBOL_GPL(component_unbind_all);
	380
	381	static int component_bind(struct component component, struct master master,
	382	void *data)
	383	{
	384	int ret;
	385
	386	/*
	387	* Each component initialises inside its own devres group.
	388	* This allows us to roll-back a failed component without
	389	* affecting anything else.
	390	*/
	391	if (!devres_open_group(master->dev, NULL, GFP_KERNEL))
	392	return -ENOMEM;
	393
	394	/*
	395	* Also open a group for the device itself: this allows us
	396	* to release the resources claimed against the sub-device
	397	* at the appropriate moment.
398	*/
399	if (!devres_open_group(component->dev, component, GFP_KERNEL)) {
400	devres_release_group(master->dev, NULL);
401	return -ENOMEM;
402	}
403
404	dev_dbg(master->dev, "binding %s (ops %ps)\n",
405	dev_name(component->dev), component->ops);
406
407	ret = component->ops->bind(component->dev, master->dev, data);
408	if (!ret) {
409	component->bound = true;
410
411	/*
412	* Close the component device's group so that resources
413	* allocated in the binding are encapsulated for removal
414	* at unbind. Remove the group on the DRM device as we
415	* can clean those resources up independently.
416	*/
417	devres_close_group(component->dev, NULL);
418	devres_remove_group(master->dev, NULL);
419
420	dev_info(master->dev, "bound %s (ops %ps)\n",
421	dev_name(component->dev), component->ops);
422	} else {
423	devres_release_group(component->dev, NULL);
424	devres_release_group(master->dev, NULL);
425
426	dev_err(master->dev, "failed to bind %s (ops %ps): %d\n",
427	dev_name(component->dev), component->ops, ret);
428	}
429
430	return ret;
431	}
432
433	int component_bind_all(struct device master_dev, void data)
434	{
435	struct master *master;
436	struct component *c;
437	int ret = 0;
438
439	WARN_ON(!mutex_is_locked(&component_mutex));
440
441	master = __master_find(master_dev, NULL);
442	if (!master)
443	return -EINVAL;
444
445	list_for_each_entry(c, &master->components, master_node) {
446	ret = component_bind(c, master, data);
447	if (ret)
448	break;
449	}
450
451	if (ret != 0) {
452	list_for_each_entry_continue_reverse(c, &master->components,
453	master_node)
454	component_unbind(c, master, data);
455	}
456
457	return ret;
458	}
459	EXPORT_SYMBOL_GPL(component_bind_all);
460
461	int component_add(struct device dev, const struct component_ops ops)
462	{
463	struct component *component;
464	int ret;
465
466	component = kzalloc(sizeof(*component), GFP_KERNEL);
467	if (!component)
468	return -ENOMEM;
469
470	component->ops = ops;
471	component->dev = dev;
472
473	dev_dbg(dev, "adding component (ops %ps)\n", ops);
474
475	mutex_lock(&component_mutex);
476	list_add_tail(&component->node, &component_list);
477
478	ret = try_to_bring_up_masters(component);
479	if (ret < 0) {
480	list_del(&component->node);
481
482	kfree(component);
483	}
484	mutex_unlock(&component_mutex);
485
486	return ret < 0 ? ret : 0;
487	}
488	EXPORT_SYMBOL_GPL(component_add);
489
490	void component_del(struct device dev, const struct component_ops ops)
491	{
492	struct component c, component = NULL;
493
494	mutex_lock(&component_mutex);
495	list_for_each_entry(c, &component_list, node)
496	if (c->dev == dev && c->ops == ops) {
497	list_del(&c->node);
498	component = c;
499	break;
500	}
501
502	if (component && component->master)
503	take_down_master(component->master);
504
505	mutex_unlock(&component_mutex);
506
507	WARN_ON(!component);
508	kfree(component);
509	}
510	EXPORT_SYMBOL_GPL(component_del);
511
512	MODULE_LICENSE("GPL v2");