driver core: Introduce device_iter_t for device iterating APIs

There are several for_each APIs which has parameter with type below:
int (*fn)(struct device *dev, void *data)
They iterate over various device lists and call @fn() for each device
with caller provided data @*data, and they usually need to modify @*data.

Give the type an dedicated typedef with advantages shown below:
typedef int (*device_iter_t)(struct device *dev, void *data)

- Shorter API declarations and definitions
- Prevent further for_each APIs from using bad parameter type

So introduce device_iter_t and apply it to various existing APIs below:
bus_for_each_dev()
(class|driver)_for_each_device()
device_for_each_child(_reverse|_reverse_from)().

Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Zijun Hu <quic_zijuhu@quicinc.com>
Link: https://lore.kernel.org/r/20250105-class_fix-v6-7-3a2f1768d4d4@quicinc.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 2 insertions, 2 deletions

diff --git a/include/linux/device/class.h b/include/linux/device/class.h
index 518c9c83d64b..aa67d4736816 100644
--- a/include/linux/device/class.h
+++ b/include/linux/device/class.h
@@ -92,8 +92,8 @@ void class_dev_iter_init(struct class_dev_iter *iter, const struct class *class,
 struct device *class_dev_iter_next(struct class_dev_iter *iter);
 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));
+int class_for_each_device(const struct class *class, const struct device *start,
+			  void *data, device_iter_t fn);
 struct device *class_find_device(const struct class *class, const struct device *start,
 				 const void *data, device_match_t match);