drivers/base: Introduce device_match_t for device finding APIs

There are several drivers/base APIs for finding a specific device, and
they currently use the following good type for the @match parameter:
int (*match)(struct device *dev, const void *data)

Since these operations do not modify the caller-provided @*data, this
type is worthy of a dedicated typedef:
typedef int (*device_match_t)(struct device *dev, const void *data)

Advantages of using device_match_t:
 - Shorter API declarations and definitions
 - Prevent further APIs from using a bad type for @match

So introduce device_match_t and apply it to the existing
(bus|class|driver|auxiliary)_find_device() APIs.

Signed-off-by: Zijun Hu <quic_zijuhu@quicinc.com>
Link: https://lore.kernel.org/r/20240813-dev_match_api-v3-1-6c6878a99b9f@quicinc.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

4 files changed, 7 insertions, 5 deletions

diff --git a/include/linux/auxiliary_bus.h b/include/linux/auxiliary_bus.h
index 662b8ae54b6a..31762324bcc9 100644
--- a/include/linux/auxiliary_bus.h
+++ b/include/linux/auxiliary_bus.h
@@ -271,6 +271,6 @@ void auxiliary_driver_unregister(struct auxiliary_driver *auxdrv);
 
 struct auxiliary_device *auxiliary_find_device(struct device *start,
 					       const void *data,
-					       int (*match)(struct device *dev, const void *data));
+					       device_match_t match);
 
 #endif /* _AUXILIARY_BUS_H_ */
diff --git a/include/linux/device/bus.h b/include/linux/device/bus.h
index 807831d6bf0f..cdc4757217f9 100644
--- a/include/linux/device/bus.h
+++ b/include/linux/device/bus.h
@@ -126,6 +126,9 @@ struct bus_attribute {
 int __must_check bus_create_file(const struct bus_type *bus, struct bus_attribute *attr);
 void bus_remove_file(const struct bus_type *bus, struct bus_attribute *attr);
 
+/* Matching function type for drivers/base APIs to find a specific device */
+typedef int (*device_match_t)(struct device *dev, const void *data);
+
 /* Generic device matching functions that all busses can use to match with */
 int device_match_name(struct device *dev, const void *name);
 int device_match_of_node(struct device *dev, const void *np);
@@ -139,8 +142,7 @@ int device_match_any(struct device *dev, const void *unused);
 int bus_for_each_dev(const struct bus_type *bus, struct device *start, void *data,
 		     int (*fn)(struct device *dev, void *data));
 struct device *bus_find_device(const struct bus_type *bus, struct device *start,
-			       const void *data,
-			       int (*match)(struct device *dev, const void *data));
+			       const void *data, device_match_t match);
 /**
  * bus_find_device_by_name - device iterator for locating a particular device
  * of a specific name.
diff --git a/include/linux/device/class.h b/include/linux/device/class.h
index c576b49c55c2..518c9c83d64b 100644
--- a/include/linux/device/class.h
+++ b/include/linux/device/class.h
@@ -95,7 +95,7 @@ void class_dev_iter_exit(struct class_dev_iter *iter);
 int class_for_each_device(const struct class *class, const struct device *start, void *data,
 			  int (*fn)(struct device *dev, void *data));
 struct device *class_find_device(const struct class *class, const struct device *start,
-				 const void *data, int (*match)(struct device *, const void *));
+				 const void *data, device_match_t match);
 
 /**
  * class_find_device_by_name - device iterator for locating a particular device
diff --git a/include/linux/device/driver.h b/include/linux/device/driver.h
index 1fc8b68786de..5c04b8e3833b 100644
--- a/include/linux/device/driver.h
+++ b/include/linux/device/driver.h
@@ -157,7 +157,7 @@ int __must_check driver_for_each_device(struct device_driver *drv, struct device
 					void *data, int (*fn)(struct device *dev, void *));
 struct device *driver_find_device(const struct device_driver *drv,
 				  struct device *start, const void *data,
-				  int (*match)(struct device *dev, const void *data));
+				  device_match_t match);
 
 /**
  * driver_find_device_by_name - device iterator for locating a particular device