mailbox: omap: Use mbox_bind_client

Use generic mbox_bind_client() to bind omap mailbox channel to a client.

mbox_bind_client is identical to the replaced lines, except that it:
 - Does the operation under con_mutex which prevents possible races in
   removal path
 - Sets TXDONE_BY_ACK if omap uses TXDONE_BY_POLL. omap uses
   TXDONE_BY_IRQ, so this check is not applicable.
 - Calls chan->mbox->ops->startup, if available. omap doesn't have, so
   this is not applicable.

Signed-off-by: Elliot Berman <quic_eberman@quicinc.com>
Signed-off-by: Jassi Brar <jaswinder.singh@linaro.org>

Author: eberman-quic

drivers/mailbox/omap-mailbox.c

@@ -417,8 +417,6 @@ struct mbox_chan *omap_mbox_request_channel(struct mbox_client *cl,
 	struct device *dev = cl->dev;
 	struct omap_mbox *mbox = NULL;
 	struct omap_mbox_device *mdev;
-	struct mbox_chan *chan;
-	unsigned long flags;
 	int ret;
 
 	if (!dev)
@@ -441,23 +439,11 @@ struct mbox_chan *omap_mbox_request_channel(struct mbox_client *cl,
 	if (!mbox || !mbox->chan)
 		return ERR_PTR(-ENOENT);
 
-	chan = mbox->chan;
-	spin_lock_irqsave(&chan->lock, flags);
-	chan->msg_free = 0;
-	chan->msg_count = 0;
-	chan->active_req = NULL;
-	chan->cl = cl;
-	init_completion(&chan->tx_complete);
-	spin_unlock_irqrestore(&chan->lock, flags);
-
-	ret = chan->mbox->ops->startup(chan);
-	if (ret) {
-		pr_err("Unable to startup the chan (%d)\n", ret);
-		mbox_free_channel(chan);
-		chan = ERR_PTR(ret);
-	}
+	ret = mbox_bind_client(mbox->chan, cl);
+	if (ret)
+		return ERR_PTR(ret);
 
-	return chan;
+	return mbox->chan;
 }
 EXPORT_SYMBOL(omap_mbox_request_channel);