mailbox: 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: Ley Foon Tan <lftan@altera.com>
Cc: Jassi Brar <jassisinghbrar@gmail.com>
Cc: nios2-dev@lists.rocketboards.org
Signed-off-by: Kees Cook <keescook@chromium.org>
diff --git a/drivers/mailbox/mailbox-altera.c b/drivers/mailbox/mailbox-altera.c
index bb682c9..bcb29df 100644
--- a/drivers/mailbox/mailbox-altera.c
+++ b/drivers/mailbox/mailbox-altera.c
@@ -57,6 +57,7 @@
 
 	/* If the controller supports only RX polling mode */
 	struct timer_list rxpoll_timer;
+	struct mbox_chan *chan;
 };
 
 static struct altera_mbox *mbox_chan_to_altera_mbox(struct mbox_chan *chan)
@@ -138,12 +139,11 @@
 	}
 }
 
-static void altera_mbox_poll_rx(unsigned long data)
+static void altera_mbox_poll_rx(struct timer_list *t)
 {
-	struct mbox_chan *chan = (struct mbox_chan *)data;
-	struct altera_mbox *mbox = mbox_chan_to_altera_mbox(chan);
+	struct altera_mbox *mbox = from_timer(mbox, t, rxpoll_timer);
 
-	altera_mbox_rx_data(chan);
+	altera_mbox_rx_data(mbox->chan);
 
 	mod_timer(&mbox->rxpoll_timer,
 		  jiffies + msecs_to_jiffies(MBOX_POLLING_MS));
@@ -206,8 +206,8 @@
 
 polling:
 	/* Setup polling timer */
-	setup_timer(&mbox->rxpoll_timer, altera_mbox_poll_rx,
-		    (unsigned long)chan);
+	mbox->chan = chan;
+	timer_setup(&mbox->rxpoll_timer, altera_mbox_poll_rx, 0);
 	mod_timer(&mbox->rxpoll_timer,
 		  jiffies + msecs_to_jiffies(MBOX_POLLING_MS));