[PATCH 1/2] component: Make a "match_add all devices matching my drivers" helper.

[Eric Anholt <eric@anholt.net>]

The body of the loop is taken from the exynos driver.  It appears to
also be useful in msm, and I've used it in vc4.

Signed-off-by: Eric Anholt <eric@anholt.net>
---

This is separated from converting exynos to use it, to let it land
separately and not have to sync between trees.

 drivers/base/component.c  | 40 ++++++++++++++++++++++++++++++++++++++++
 include/linux/component.h |  5 +++++
 2 files changed, 45 insertions(+)

diff --git a/drivers/base/component.c b/drivers/base/component.c
index f748430..08167a3 100644
--- a/drivers/base/component.c
+++ b/drivers/base/component.c
@@ -16,6 +16,7 @@
 #include <linux/list.h>
 #include <linux/module.h>
 #include <linux/mutex.h>
+#include <linux/platform_device.h>
 #include <linux/slab.h>
 
 struct component_match {
@@ -283,6 +284,45 @@ void component_match_add(struct device *dev, struct component_match **matchptr,
 }
 EXPORT_SYMBOL(component_match_add);
 
+static int compare_dev(struct device *dev, void *data)
+{
+	return dev == (struct device *)data;
+}
+
+/**
+ * component_match_add_platform_drivers - For each driver passed in,
+ * finds each device that probed with it and adds it as a component
+ * driver to the match list.
+ * @dev:     master device for the components
+ * @match:   pointer to the match structure pointer.  For the first
+ *           component_match_add(), this should be a pointer to a NULL
+ *           pointer, which will get filled in by the call.
+ * @drivers: array of platform drivers whose devices should all be
+ *           added to the match
+ * @count:   number of platform drivers to match
+ */
+void component_match_add_platform_drivers(struct device *dev,
+					  struct component_match **match,
+					  struct platform_driver *const *drivers,
+					  int count)
+{
+	int i;
+
+	for (i = 0; i < count; i++) {
+		struct device_driver *drv = &drivers[i]->driver;
+		struct device *p = NULL, *d;
+
+		while ((d = bus_find_device(&platform_bus_type, p, drv,
+					    (void *)platform_bus_type.match))) {
+			put_device(p);
+			component_match_add(dev, match, compare_dev, d);
+			p = d;
+		}
+		put_device(p);
+	}
+}
+EXPORT_SYMBOL_GPL(component_match_add_platform_drivers);
+
 int component_master_add_with_match(struct device *dev,
 	const struct component_master_ops *ops,
 	struct component_match *match)
diff --git a/include/linux/component.h b/include/linux/component.h
index c00dcc3..2d74420 100644
--- a/include/linux/component.h
+++ b/include/linux/component.h
@@ -2,6 +2,7 @@
 #define COMPONENT_H
 
 struct device;
+struct platform_driver;
 
 struct component_ops {
 	int (*bind)(struct device *, struct device *, void *);
@@ -35,5 +36,9 @@ int component_master_add_with_match(struct device *,
 	const struct component_master_ops *, struct component_match *);
 void component_match_add(struct device *, struct component_match **,
 	int (*compare)(struct device *, void *), void *compare_data);
+void component_match_add_platform_drivers(struct device *dev,
+					  struct component_match **match,
+					  struct platform_driver *const *drivers,
+					  int count);
 
 #endif
-- 
2.1.4