[RFC PATCH 17/57] drivers: Add generic match by device type helper

[Suzuki K Poulose]

Add a generic helper routine to match the device type of
a given device.

Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Cc: "Rafael J. Wysocki" <rafael@xxxxxxxxxx>
Cc: Ulf Hansson <ulf.hansson@xxxxxxxxxx>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@xxxxxxx>
---
 drivers/base/core.c    |  6 ++++++
 include/linux/device.h | 15 +++++++++++++++
 2 files changed, 21 insertions(+)

diff --git a/drivers/base/core.c b/drivers/base/core.c
index 141c4f8..9df812f 100644
--- a/drivers/base/core.c
+++ b/drivers/base/core.c
@@ -3340,3 +3340,9 @@ int device_match_fwnode(struct device *dev, void *fwnode)
 	return dev_fwnode(dev) == fwnode;
 }
 EXPORT_SYMBOL_GPL(device_match_fwnode);
+
+int device_match_devt(struct device *dev, void *pdevt)
+{
+	return dev->devt == *(dev_t *)pdevt;
+}
+EXPORT_SYMBOL_GPL(device_match_devt);
diff --git a/include/linux/device.h b/include/linux/device.h
index 54be931..83c0745 100644
--- a/include/linux/device.h
+++ b/include/linux/device.h
@@ -165,6 +165,7 @@ void subsys_dev_iter_exit(struct subsys_dev_iter *iter);
 
 int device_match_of_node(struct device *dev, void *np);
 int device_match_fwnode(struct device *dev, void *fwnode);
+int device_match_devt(struct device *dev, void *pdevt);
 
 int bus_for_each_dev(struct bus_type *bus, struct device *start, void *data,
 		     int (*fn)(struct device *dev, void *data));
@@ -203,6 +204,20 @@ static inline struct device *bus_find_device_by_fwnode(struct bus_type *bus,
 	return bus_find_device(bus, start, fwnode, device_match_fwnode);
 }
 
+/**
+ * bus_find_device_by_devt : device iterator for locating a particular device
+ * matching the device type.
+ * @bus: bus type
+ * @start: Device to begin with
+ * @devt: device type of the device to match.
+ */
+static inline struct device *bus_find_device_by_devt(struct bus_type *bus,
+						     struct device *start,
+						     dev_t devt)
+{
+	return bus_find_device(bus, start, &devt, device_match_devt);
+}
+
 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,
-- 
2.7.4