drm/vc4: Convert timers to use timer_setup()

In preparation for unconditionally passing the struct timer_list pointer to
all timer callbacks, switch to using the new timer_setup() and from_timer()
to pass the timer pointer explicitly.

Cc: Eric Anholt <eric@anholt.net>
Cc: David Airlie <airlied@linux.ie>
Cc: dri-devel@lists.freedesktop.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Eric Anholt <eric@anholt.net>
Link: https://patchwork.freedesktop.org/patch/msgid/20171024151648.GA104538@beast
Reviewed-by: Eric Anholt <eric@anholt.net>
diff --git a/drivers/gpu/drm/vc4/vc4_bo.c b/drivers/gpu/drm/vc4/vc4_bo.c
index 98a6cb9..4ae45d7 100644
--- a/drivers/gpu/drm/vc4/vc4_bo.c
+++ b/drivers/gpu/drm/vc4/vc4_bo.c
@@ -674,10 +674,9 @@ void vc4_bo_dec_usecnt(struct vc4_bo *bo)
 	mutex_unlock(&bo->madv_lock);
 }
 
-static void vc4_bo_cache_time_timer(unsigned long data)
+static void vc4_bo_cache_time_timer(struct timer_list *t)
 {
-	struct drm_device *dev = (struct drm_device *)data;
-	struct vc4_dev *vc4 = to_vc4_dev(dev);
+	struct vc4_dev *vc4 = from_timer(vc4, t, bo_cache.time_timer);
 
 	schedule_work(&vc4->bo_cache.time_work);
 }
@@ -1039,9 +1038,7 @@ int vc4_bo_cache_init(struct drm_device *dev)
 	INIT_LIST_HEAD(&vc4->bo_cache.time_list);
 
 	INIT_WORK(&vc4->bo_cache.time_work, vc4_bo_cache_time_work);
-	setup_timer(&vc4->bo_cache.time_timer,
-		    vc4_bo_cache_time_timer,
-		    (unsigned long)dev);
+	timer_setup(&vc4->bo_cache.time_timer, vc4_bo_cache_time_timer, 0);
 
 	return 0;
 }