1 files changed, 117 insertions, 3 deletions

diff --git a/drivers/base/component.c b/drivers/base/component.c
index 55813e91bf0d..b4236daed4fa 100644
--- a/drivers/base/component.c
+++ b/drivers/base/component.c
@@ -18,6 +18,15 @@
 #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;
@@ -25,6 +34,7 @@ struct master {
 
 	const struct component_master_ops *ops;
 	struct device *dev;
+	struct component_match *match;
 };
 
 struct component {
@@ -96,6 +106,34 @@ int component_master_add_child(struct master *master,
 }
 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)
 {
@@ -128,7 +166,7 @@ static int try_to_bring_up_master(struct master *master,
 	 * Search the list of components, looking for components that
 	 * belong to this master, and attach them to the master.
 	 */
-	if (master->ops->add_components(master->dev, master)) {
+	if (find_components(master)) {
 		/* Failed to find all components */
 		ret = 0;
 		goto out;
@@ -186,18 +224,87 @@ static void take_down_master(struct master *master)
 	master_remove_components(master);
 }
 
-int component_master_add(struct device *dev,
-	const struct component_master_ops *ops)
+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;
+
+	/* 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. */
@@ -215,6 +322,13 @@ int component_master_add(struct device *dev,
 
 	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,