Use consistent function signatures when handling function pointers

This fixes compilation with gcc-15.

Author: Alexander Golubev <fatzer2@gmail.com>
Bug: https://bugs.gentoo.org/944303
Bug: https://bugs.gentoo.org/946207
Bug: https://bugs.gentoo.org/947851
Bug: https://bugs.gentoo.org/948138
Origin: Self-created patch to fix the gentoo bug
diff --git a/src/class_backlight.h b/src/class_backlight.h
index db2ccdf..41f9e6a 100644
--- a/src/class_backlight.h
+++ b/src/class_backlight.h
@@ -40,7 +40,7 @@ struct driver_backlight {
 	char *name;
 	int  (*get_brightness)();
 	int  (*get_brightness_max)();
-	void (*set_brightness)();
+	void (*set_brightness)(int val);
 	void (*driver_exit)();
 };
 
diff --git a/src/input_manager.c b/src/input_manager.c
index dbbfc6b..1dcc61c 100644
--- a/src/input_manager.c
+++ b/src/input_manager.c
@@ -382,7 +382,7 @@ handleInputSource (GIOChannel *io, GIOCondition condition, gpointer data)
  * @{
  */
 InputSource*
-addInputSource (int fd, int (*handler)(), gpointer user_data, gboolean close_on_exit)
+addInputSource (int fd, int (*handler)(int fd, gpointer user_data), gpointer user_data, gboolean close_on_exit)
 {
 	struct moddata_inputmanager *base = &modbase_inputmanager;
 	InputSource *src;
diff --git a/src/input_manager.h b/src/input_manager.h
index b65a500..b2de0d5 100644
--- a/src/input_manager.h
+++ b/src/input_manager.h
@@ -15,7 +15,7 @@
 #include <glib.h>
 #include <pbbtaglist.h>
 
-typedef void (*inputqueue_t)();
+typedef void (*inputqueue_t)(struct tagitem *taglist);
 
 #define MAXINPUTS   16
 #define TIMERCOUNT  3     /* ATTENTION: keep an eye on the init routine */
@@ -65,8 +65,8 @@ gint cbEventDevices (gconstpointer a, gconstpointer b);
 void scanEventDevices ();
 void destroyInputSource (gpointer data);
 gboolean handleInputSource (GIOChannel *io, GIOCondition condition, gpointer data);
-InputSource *addInputSource (int fd, int (*handler)(), gpointer user_data, gboolean close_on_exit);
-int register_function (int queueid, void (*func)());
+InputSource *addInputSource (int fd, int (*handler)(int fd, gpointer user_data), gpointer user_data, gboolean close_on_exit);
+int register_function (int queueid, inputqueue_t func);
 long process_queue_single (int queueid, long tag, long data);
 int process_queue (int queueid, struct tagitem *taglist);
 void ipc_handler ();
diff --git a/src/input_manager.c b/src/input_manager.c
index 1dcc61c..908d821 100644
--- a/src/input_manager.c
+++ b/src/input_manager.c
@@ -421,7 +421,7 @@ addInputSource (int fd, int (*handler)(int fd, gpointer user_data), gpointer use
 /* --- queue managers --- */
 
 int
-register_function (int queueid, void (*func)())
+register_function (int queueid, inputqueue_t func)
 {
   struct moddata_inputmanager *base = &modbase_inputmanager;
   inputqueue_t *queue = base->iqueues[queueid];
@@ -486,12 +486,14 @@ process_queue (int queueid, struct tagitem *taglist)
  * were successful.
  */ 
 void
-ipc_handler ()
+ipc_handler (struct tagitem *taglist)
 {
 	struct pbbmessage *msg;
 	struct tagitem *source, *dest;
 	char msgbuffer[8192];
 
+	(void) taglist; /* unused */
+
 	if ((ipc_receive (msgbuffer, sizeof(msgbuffer))) == 0) {
 		msg = (struct pbbmessage *) msgbuffer;
 		switch (msg->action) {
diff --git a/src/input_manager.h b/src/input_manager.h
index b2de0d5..ea78bf8 100644
--- a/src/input_manager.h
+++ b/src/input_manager.h
@@ -69,7 +69,7 @@ InputSource *addInputSource (int fd, int (*handler)(int fd, gpointer user_data),
 int register_function (int queueid, inputqueue_t func);
 long process_queue_single (int queueid, long tag, long data);
 int process_queue (int queueid, struct tagitem *taglist);
-void ipc_handler ();
+void ipc_handler (struct tagitem *taglist);
 gboolean input_event_handler (int fd, gpointer user_data);
 /*gboolean mice_handler (int fd, gpointer user_data);*/
 gboolean cb_timer100 (gpointer data);