Merge tag 'iomap-4.21-merge-3' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux

[linux.git] / drivers / mailbox / mailbox.c

diff --git a/drivers/mailbox/mailbox.c b/drivers/mailbox/mailbox.c
index 674b35f402f5e939833bdbde4a39399689d653f9..c6a7d4582dc6790be3a50f545faa36bc07ea8a7f 100644 (file)
--- a/drivers/mailbox/mailbox.c
+++ b/drivers/mailbox/mailbox.c
@@ -283,6 +283,34 @@ int mbox_send_message(struct mbox_chan *chan, void *mssg)
 }
 EXPORT_SYMBOL_GPL(mbox_send_message);
 
+/**
+ * mbox_flush - flush a mailbox channel
+ * @chan: mailbox channel to flush
+ * @timeout: time, in milliseconds, to allow the flush operation to succeed
+ *
+ * Mailbox controllers that need to work in atomic context can implement the
+ * ->flush() callback to busy loop until a transmission has been completed.
+ * The implementation must call mbox_chan_txdone() upon success. Clients can
+ * call the mbox_flush() function at any time after mbox_send_message() to
+ * flush the transmission. After the function returns success, the mailbox
+ * transmission is guaranteed to have completed.
+ *
+ * Returns: 0 on success or a negative error code on failure.
+ */
+int mbox_flush(struct mbox_chan *chan, unsigned long timeout)
+{
+       int ret;
+
+       if (!chan->mbox->ops->flush)
+               return -ENOTSUPP;
+
+       ret = chan->mbox->ops->flush(chan, timeout);
+       if (ret < 0)
+               tx_tick(chan, ret);
+
+       return ret;
+}
+
 /**
  * mbox_request_channel - Request a mailbox channel.
  * @cl: Identity of the client requesting the channel.
@@ -327,7 +355,8 @@ struct mbox_chan *mbox_request_channel(struct mbox_client *cl, int index)
        list_for_each_entry(mbox, &mbox_cons, node)
                if (mbox->dev->of_node == spec.np) {
                        chan = mbox->of_xlate(mbox, &spec);
-                       break;
+                       if (!IS_ERR(chan))
+                               break;
                }
 
        of_node_put(spec.np);
@@ -515,3 +544,73 @@ void mbox_controller_unregister(struct mbox_controller *mbox)
        mutex_unlock(&con_mutex);
 }
 EXPORT_SYMBOL_GPL(mbox_controller_unregister);
+
+static void __devm_mbox_controller_unregister(struct device *dev, void *res)
+{
+       struct mbox_controller **mbox = res;
+
+       mbox_controller_unregister(*mbox);
+}
+
+static int devm_mbox_controller_match(struct device *dev, void *res, void *data)
+{
+       struct mbox_controller **mbox = res;
+
+       if (WARN_ON(!mbox || !*mbox))
+               return 0;
+
+       return *mbox == data;
+}
+
+/**
+ * devm_mbox_controller_register() - managed mbox_controller_register()
+ * @dev: device owning the mailbox controller being registered
+ * @mbox: mailbox controller being registered
+ *
+ * This function adds a device-managed resource that will make sure that the
+ * mailbox controller, which is registered using mbox_controller_register()
+ * as part of this function, will be unregistered along with the rest of
+ * device-managed resources upon driver probe failure or driver removal.
+ *
+ * Returns 0 on success or a negative error code on failure.
+ */
+int devm_mbox_controller_register(struct device *dev,
+                                 struct mbox_controller *mbox)
+{
+       struct mbox_controller **ptr;
+       int err;
+
+       ptr = devres_alloc(__devm_mbox_controller_unregister, sizeof(*ptr),
+                          GFP_KERNEL);
+       if (!ptr)
+               return -ENOMEM;
+
+       err = mbox_controller_register(mbox);
+       if (err < 0) {
+               devres_free(ptr);
+               return err;
+       }
+
+       devres_add(dev, ptr);
+       *ptr = mbox;
+
+       return 0;
+}
+EXPORT_SYMBOL_GPL(devm_mbox_controller_register);
+
+/**
+ * devm_mbox_controller_unregister() - managed mbox_controller_unregister()
+ * @dev: device owning the mailbox controller being unregistered
+ * @mbox: mailbox controller being unregistered
+ *
+ * This function unregisters the mailbox controller and removes the device-
+ * managed resource that was set up to automatically unregister the mailbox
+ * controller on driver probe failure or driver removal. It's typically not
+ * necessary to call this function.
+ */
+void devm_mbox_controller_unregister(struct device *dev, struct mbox_controller *mbox)
+{
+       WARN_ON(devres_release(dev, __devm_mbox_controller_unregister,
+                              devm_mbox_controller_match, mbox));
+}
+EXPORT_SYMBOL_GPL(devm_mbox_controller_unregister);