[PATCH] Driver core: add bus_find_device_by_fwnode

From: Silesh C V
Date: Mon Sep 24 2018 - 00:36:23 EST


Some drivers need to find the device on a bus having a specific firmware
node. Currently, such drivers have their own implementations to do this.
Provide a helper similar to bus_find_device_by_name so that each driver
does not have to reinvent this.

Signed-off-by: Silesh C V <svellattu@xxxxxxxxxx>
---
drivers/base/bus.c | 26 ++++++++++++++++++++++++++
include/linux/device.h | 3 +++
2 files changed, 29 insertions(+)

diff --git a/drivers/base/bus.c b/drivers/base/bus.c
index 8bfd27e..148b198 100644
--- a/drivers/base/bus.c
+++ b/drivers/base/bus.c
@@ -17,6 +17,7 @@
#include <linux/string.h>
#include <linux/mutex.h>
#include <linux/sysfs.h>
+#include <linux/of.h>
#include "base.h"
#include "power/power.h"

@@ -373,6 +374,31 @@ struct device *bus_find_device_by_name(struct bus_type *bus,
}
EXPORT_SYMBOL_GPL(bus_find_device_by_name);

+static int match_fwnode(struct device *dev, void *data)
+{
+ struct fwnode_handle *fwnode = data;
+ struct device_node *of_node = to_of_node(fwnode);
+
+ if (of_node)
+ return dev->of_node == of_node;
+ else
+ return dev->fwnode == fwnode;
+}
+
+/**
+ * bus_find_device_by_fwnode - device iterator for locating a particular device
+ * having a specific firmware node
+ * @bus: bus type
+ * @start: Device to begin with
+ * @fwnode: firmware node of the device to match
+ */
+struct device *bus_find_device_by_fwnode(struct bus_type *bus, struct device *start,
+ struct fwnode_handle *fwnode)
+{
+ return bus_find_device(bus, start, (void *)fwnode, match_fwnode);
+}
+EXPORT_SYMBOL_GPL(bus_find_device_by_fwnode);
+
/**
* subsys_find_device_by_id - find a device with a specific enumeration number
* @subsys: subsystem
diff --git a/include/linux/device.h b/include/linux/device.h
index 8f88254..09384f6 100644
--- a/include/linux/device.h
+++ b/include/linux/device.h
@@ -171,6 +171,9 @@ struct device *bus_find_device(struct bus_type *bus, struct device *start,
struct device *bus_find_device_by_name(struct bus_type *bus,
struct device *start,
const char *name);
+struct device *bus_find_device_by_fwnode(struct bus_type *bus,
+ struct device *start,
+ struct fwnode_handle *fwnode);
struct device *subsys_find_device_by_id(struct bus_type *bus, unsigned int id,
struct device *hint);
int bus_for_each_drv(struct bus_type *bus, struct device_driver *start,
--
1.9.1