See: https://lkml.org/lkml/2017/11/25/90

diff -urNZ a/src/wl/sys/wl_linux.c b/src/wl/sys/wl_linux.c
--- a/src/wl/sys/wl_linux.c	2015-09-18 22:47:30.000000000 +0000
+++ b/src/wl/sys/wl_linux.c	2018-01-31 22:52:10.859856221 +0000
@@ -93,7 +93,11 @@

 #include <wlc_wowl.h>

+#if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 15, 0)
+static void wl_timer(struct timer_list *tl);
+#else
 static void wl_timer(ulong data);
+#endif
 static void _wl_timer(wl_timer_t *t);
 static struct net_device *wl_alloc_linux_if(wl_if_t *wlif);

@@ -2298,9 +2302,15 @@
 }

 static void
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 15, 0)
+wl_timer(struct timer_list *tl)
+{
+	wl_timer_t *t = from_timer(t, tl, timer);
+#else
 wl_timer(ulong data)
 {
 	wl_timer_t *t = (wl_timer_t *)data;
+#endif

 	if (!WL_ALL_PASSIVE_ENAB(t->wl))
 		_wl_timer(t);
@@ -2352,9 +2362,13 @@

 	bzero(t, sizeof(wl_timer_t));

+#if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 15, 0)
+	timer_setup(&t->timer, wl_timer, 0);
+#else
 	init_timer(&t->timer);
 	t->timer.data = (ulong) t;
 	t->timer.function = wl_timer;
+#endif
 	t->wl = wl;
 	t->fn = fn;
 	t->arg = arg;