[PATCH v5 05/23] 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 at ventanamicro.com>
---
 drivers/mailbox/mailbox.c          | 45 +++++++++++++++++-------------
 include/linux/mailbox_controller.h |  3 ++
 2 files changed, 28 insertions(+), 20 deletions(-)

diff --git a/drivers/mailbox/mailbox.c b/drivers/mailbox/mailbox.c
index 5cd8ae222073..d1840eace725 100644
--- a/drivers/mailbox/mailbox.c
+++ b/drivers/mailbox/mailbox.c
@@ -15,6 +15,7 @@
 #include <linux/module.h>
 #include <linux/mutex.h>
 #include <linux/of.h>
+#include <linux/property.h>
 #include <linux/spinlock.h>
 
 #include "mailbox.h"
@@ -383,34 +384,46 @@ 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;
+	unsigned int i;
 	int ret;
 
-	if (!dev || !dev->of_node) {
-		pr_debug("%s: No owner device node\n", __func__);
+	if (!dev || !dev_fwnode(dev)) {
+		pr_debug("No owner %s\n", dev ? "fwnode" : "device");
 		return ERR_PTR(-ENODEV);
 	}
 
-	ret = of_parse_phandle_with_args(dev->of_node, "mboxes", "#mbox-cells",
-					 index, &spec);
+	ret = fwnode_property_get_reference_args(dev_fwnode(dev), "mboxes",
+						 "#mbox-cells", 0, index, &fwspec);
 	if (ret) {
 		dev_err(dev, "%s: can't parse \"mboxes\" property\n", __func__);
 		return ERR_PTR(ret);
 	}
 
+	spec.np = to_of_node(fwspec.fwnode);
+	spec.args_count = fwspec.nargs;
+	for (i = 0; i < spec.args_count; i++)
+		spec.args[i] = fwspec.args[i];
+
 	scoped_guard(mutex, &con_mutex) {
 		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 && dev_fwnode(mbox->dev) == 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);
+		fwnode_handle_put(fwspec.fwnode);
 
 		if (IS_ERR(chan))
 			return chan;
@@ -427,15 +440,8 @@ 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);
@@ -470,9 +476,8 @@ 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)
+static struct mbox_chan *fw_mbox_index_xlate(struct mbox_controller *mbox,
+					     const struct fwnode_reference_args *sp)
 {
 	int ind = sp->args[0];
 
@@ -523,8 +528,8 @@ 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;
 
 	scoped_guard(mutex, &con_mutex)
 		list_add_tail(&mbox->node, &mbox_cons);
diff --git a/include/linux/mailbox_controller.h b/include/linux/mailbox_controller.h
index ad01c4082358..80a427c7ca29 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