driver core: Constify API device_find_child() and adapt for various usages

Constify the following API:
struct device *device_find_child(struct device *dev, void *data,
		int (*match)(struct device *dev, void *data));
To :
struct device *device_find_child(struct device *dev, const void *data,
                                 device_match_t match);
typedef int (*device_match_t)(struct device *dev, const void *data);
with the following reasons:

- Protect caller's match data @*data which is for comparison and lookup
  and the API does not actually need to modify @*data.

- Make the API's parameters (@match)() and @data have the same type as
  all of other device finding APIs (bus|class|driver)_find_device().

- All kinds of existing device match functions can be directly taken
  as the API's argument, they were exported by driver core.

Constify the API and adapt for various existing usages.

BTW, various subsystem changes are squashed into this commit to meet
'git bisect' requirement, and this commit has the minimal and simplest
changes to complement squashing shortcoming, and that may bring extra
code improvement.

Reviewed-by: Alison Schofield <alison.schofield@intel.com>
Reviewed-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Acked-by: Uwe Kleine-König <ukleinek@kernel.org> # for drivers/pwm
Signed-off-by: Zijun Hu <quic_zijuhu@quicinc.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Link: https://lore.kernel.org/r/20241224-const_dfc_done-v5-4-6623037414d4@quicinc.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 2 insertions, 2 deletions

diff --git a/include/scsi/scsi_transport_iscsi.h b/include/scsi/scsi_transport_iscsi.h
index bd1243657c01..4d3baf324900 100644
--- a/include/scsi/scsi_transport_iscsi.h
+++ b/include/scsi/scsi_transport_iscsi.h
@@ -497,8 +497,8 @@ extern void iscsi_destroy_all_flashnode(struct Scsi_Host *shost);
 extern int iscsi_flashnode_bus_match(struct device *dev,
 				     const struct device_driver *drv);
 extern struct device *
-iscsi_find_flashnode_sess(struct Scsi_Host *shost, void *data,
-			  int (*fn)(struct device *dev, void *data));
+iscsi_find_flashnode_sess(struct Scsi_Host *shost, const void *data,
+			  device_match_t fn);
 extern struct device *
 iscsi_find_flashnode_conn(struct iscsi_bus_flash_session *fnode_sess);