mailbox: Make startup and shutdown ops optional

Some mailbox hardware doesn't have to perform any additional operations
on startup of shutdown, so make these optional.

Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Signed-off-by: Jassi Brar <jaswinder.singh@linaro.org>

diff --git a/drivers/mailbox/mailbox.c b/drivers/mailbox/mailbox.c
index 9dfbf7ea10a230579fbe4d102d491b045a8ea5b2..537f4f6d009b2d0dbd1eeac62dd20212eef3fb02 100644 (file)
--- a/drivers/mailbox/mailbox.c
+++ b/drivers/mailbox/mailbox.c
@@ -355,11 +355,14 @@ struct mbox_chan *mbox_request_channel(struct mbox_client *cl, int index)
 
        spin_unlock_irqrestore(&chan->lock, flags);
 
-       ret = chan->mbox->ops->startup(chan);
-       if (ret) {
-               dev_err(dev, "Unable to startup the chan (%d)\n", ret);
-               mbox_free_channel(chan);
-               chan = ERR_PTR(ret);
+       if (chan->mbox->ops->startup) {
+               ret = chan->mbox->ops->startup(chan);
+
+               if (ret) {
+                       dev_err(dev, "Unable to startup the chan (%d)\n", ret);
+                       mbox_free_channel(chan);
+                       chan = ERR_PTR(ret);
+               }
        }
 
        mutex_unlock(&con_mutex);
@@ -408,7 +411,8 @@ void mbox_free_channel(struct mbox_chan *chan)
        if (!chan || !chan->cl)
                return;
 
-       chan->mbox->ops->shutdown(chan);
+       if (chan->mbox->ops->shutdown)
+               chan->mbox->ops->shutdown(chan);
 
        /* The queued TX requests are simply aborted, no callbacks are made */
        spin_lock_irqsave(&chan->lock, flags);