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-rw-r--r--drivers/base/bus.c34
1 files changed, 34 insertions, 0 deletions
diff --git a/drivers/base/bus.c b/drivers/base/bus.c
index c3fac7f..2c64b79 100644
--- a/drivers/base/bus.c
+++ b/drivers/base/bus.c
@@ -177,6 +177,39 @@ int bus_for_each_dev(struct bus_type * bus, struct device * start,
return error;
}
+/**
+ * bus_find_device - device iterator for locating a particular device.
+ * @bus: bus type
+ * @start: Device to begin with
+ * @data: Data to pass to match function
+ * @match: Callback function to check device
+ *
+ * This is similar to the bus_for_each_dev() function above, but it
+ * returns a reference to a device that is 'found' for later use, as
+ * determined by the @match callback.
+ *
+ * The callback should return 0 if the device doesn't match and non-zero
+ * if it does. If the callback returns non-zero, this function will
+ * return to the caller and not iterate over any more devices.
+ */
+struct device * bus_find_device(struct bus_type *bus,
+ struct device *start, void *data,
+ int (*match)(struct device *, void *))
+{
+ struct klist_iter i;
+ struct device *dev;
+
+ if (!bus)
+ return NULL;
+
+ klist_iter_init_node(&bus->klist_devices, &i,
+ (start ? &start->knode_bus : NULL));
+ while ((dev = next_device(&i)))
+ if (match(dev, data) && get_device(dev))
+ break;
+ klist_iter_exit(&i);
+ return dev;
+}
static struct device_driver * next_driver(struct klist_iter * i)
@@ -557,6 +590,7 @@ int __init buses_init(void)
EXPORT_SYMBOL_GPL(bus_for_each_dev);
+EXPORT_SYMBOL_GPL(bus_find_device);
EXPORT_SYMBOL_GPL(bus_for_each_drv);
EXPORT_SYMBOL_GPL(bus_add_device);
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