[RFC PATCH v2 06/17] mailbox: Allow controller specific mapping using fwnode

[Anup Patel]

Introduce optional fw_node() callback which allows a mailbox controller
driver to provide controller specific mapping using fwnode.

The Linux OF framework already implements fwnode operations for the
Linux DD framework so the fw_xlate() callback works fine with device
tree as well.

Signed-off-by: Anup Patel <apatel@xxxxxxxxxxxxxxxx>
---
 drivers/mailbox/mailbox.c          | 44 ++++++++++++++++++------------
 include/linux/mailbox_controller.h |  3 ++
 2 files changed, 29 insertions(+), 18 deletions(-)

diff --git a/drivers/mailbox/mailbox.c b/drivers/mailbox/mailbox.c
index d3d26a2c9895..447edd212f0f 100644
--- a/drivers/mailbox/mailbox.c
+++ b/drivers/mailbox/mailbox.c
@@ -402,20 +402,29 @@ EXPORT_SYMBOL_GPL(mbox_bind_client);
  */
 struct mbox_chan *mbox_request_channel(struct mbox_client *cl, int index)
 {
+	struct fwnode_reference_args fwspec;
 	struct device *dev = cl->dev;
 	struct mbox_controller *mbox;
 	struct of_phandle_args spec;
 	struct mbox_chan *chan;
 	int ret;
 
-	if (!dev || !dev->of_node) {
-		pr_debug("%s: No owner device node\n", __func__);
+	if (!dev) {
+		pr_debug("%s: No owner device\n", __func__);
 		return ERR_PTR(-ENODEV);
 	}
 
 	mutex_lock(&con_mutex);
 
-	if (of_parse_phandle_with_args(dev->of_node, "mboxes",
+	if (fwnode_property_get_reference_args(dev->fwnode, "mboxes",
+					       "#mbox-cells", 0, index, &fwspec)) {
+		dev_dbg(dev, "%s: can't parse \"mboxes\" property\n", __func__);
+		mutex_unlock(&con_mutex);
+		return ERR_PTR(-ENODEV);
+	}
+
+	if (dev->of_node &&
+	    of_parse_phandle_with_args(dev->of_node, "mboxes",
 				       "#mbox-cells", index, &spec)) {
 		dev_dbg(dev, "%s: can't parse \"mboxes\" property\n", __func__);
 		mutex_unlock(&con_mutex);
@@ -423,14 +432,20 @@ struct mbox_chan *mbox_request_channel(struct mbox_client *cl, int index)
 	}
 
 	chan = ERR_PTR(-EPROBE_DEFER);
-	list_for_each_entry(mbox, &mbox_cons, node)
-		if (mbox->dev->of_node == spec.np) {
+	list_for_each_entry(mbox, &mbox_cons, node) {
+		if (mbox->fw_xlate && mbox->dev->fwnode == fwspec.fwnode) {
+			chan = mbox->fw_xlate(mbox, &fwspec);
+			if (!IS_ERR(chan))
+				break;
+		} else if (mbox->of_xlate && mbox->dev->of_node == spec.np) {
 			chan = mbox->of_xlate(mbox, &spec);
 			if (!IS_ERR(chan))
 				break;
 		}
+	}
 
-	of_node_put(spec.np);
+	if (dev->of_node)
+		of_node_put(spec.np);
 
 	if (IS_ERR(chan)) {
 		mutex_unlock(&con_mutex);
@@ -449,15 +464,8 @@ EXPORT_SYMBOL_GPL(mbox_request_channel);
 struct mbox_chan *mbox_request_channel_byname(struct mbox_client *cl,
 					      const char *name)
 {
-	struct device_node *np = cl->dev->of_node;
-	int index;
-
-	if (!np) {
-		dev_err(cl->dev, "%s() currently only supports DT\n", __func__);
-		return ERR_PTR(-EINVAL);
-	}
+	int index = device_property_match_string(cl->dev, "mbox-names", name);
 
-	index = of_property_match_string(np, "mbox-names", name);
 	if (index < 0) {
 		dev_err(cl->dev, "%s() could not locate channel named \"%s\"\n",
 			__func__, name);
@@ -495,8 +503,8 @@ void mbox_free_channel(struct mbox_chan *chan)
 EXPORT_SYMBOL_GPL(mbox_free_channel);
 
 static struct mbox_chan *
-of_mbox_index_xlate(struct mbox_controller *mbox,
-		    const struct of_phandle_args *sp)
+fw_mbox_index_xlate(struct mbox_controller *mbox,
+		    const struct fwnode_reference_args *sp)
 {
 	int ind = sp->args[0];
 
@@ -549,8 +557,8 @@ int mbox_controller_register(struct mbox_controller *mbox)
 		spin_lock_init(&chan->lock);
 	}
 
-	if (!mbox->of_xlate)
-		mbox->of_xlate = of_mbox_index_xlate;
+	if (!mbox->fw_xlate && !mbox->of_xlate)
+		mbox->fw_xlate = fw_mbox_index_xlate;
 
 	mutex_lock(&con_mutex);
 	list_add_tail(&mbox->node, &mbox_cons);
diff --git a/include/linux/mailbox_controller.h b/include/linux/mailbox_controller.h
index 6fee33cb52f5..74352c244aba 100644
--- a/include/linux/mailbox_controller.h
+++ b/include/linux/mailbox_controller.h
@@ -66,6 +66,7 @@ struct mbox_chan_ops {
  *			no interrupt rises. Ignored if 'txdone_irq' is set.
  * @txpoll_period:	If 'txdone_poll' is in effect, the API polls for
  *			last TX's status after these many millisecs
+ * @fw_xlate:		Controller driver specific mapping of channel via fwnode
  * @of_xlate:		Controller driver specific mapping of channel via DT
  * @poll_hrt:		API private. hrtimer used to poll for TXDONE on all
  *			channels.
@@ -79,6 +80,8 @@ struct mbox_controller {
 	bool txdone_irq;
 	bool txdone_poll;
 	unsigned txpoll_period;
+	struct mbox_chan *(*fw_xlate)(struct mbox_controller *mbox,
+				      const struct fwnode_reference_args *sp);
 	struct mbox_chan *(*of_xlate)(struct mbox_controller *mbox,
 				      const struct of_phandle_args *sp);
 	/* Internal to API */
-- 
2.43.0