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>

1 files changed, 10 insertions, 6 deletions

diff --git a/drivers/mailbox/mailbox.c b/drivers/mailbox/mailbox.c
index 9dfbf7ea10a2..537f4f6d009b 100644
--- 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);