[PATCH v7 3/3] i2c: mux: Propagate software nodes to channel adapters

[Ahmad Byagowi]

Device Tree channel nodes are associated with the adapters created by
i2c-mux, but equivalent software-node descriptions are not.

Use generic firmware-node operations for the existing channel lookup and
accept either an OF node or a software node. Associate the returned node
with the adapter so child I2C devices can be instantiated from
software-node properties.

Save the adapter firmware node before adapter deletion and release the
reference afterwards, following the lifetime pattern in i2c-atr.

Signed-off-by: Ahmad Byagowi <ahmadexp@xxxxxxxxx>
---
 drivers/i2c/i2c-mux.c | 45 +++++++++++++++++++++----------------------
 1 file changed, 22 insertions(+), 23 deletions(-)

diff --git a/drivers/i2c/i2c-mux.c b/drivers/i2c/i2c-mux.c
index a8b94b97a725..b37d36d3b121 100644
--- a/drivers/i2c/i2c-mux.c
+++ b/drivers/i2c/i2c-mux.c
@@ -25,6 +25,7 @@
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/of.h>
+#include <linux/property.h>
 #include <linux/slab.h>
 #include <linux/sysfs.h>
 
@@ -264,40 +265,40 @@ static const struct i2c_lock_operations i2c_parent_lock_ops = {
 	.unlock_bus =  i2c_parent_unlock_bus,
 };
 
-static struct device_node *
+static struct fwnode_handle *
 i2c_mux_get_channel_node(struct i2c_mux_core *muxc, u32 chan_id)
 {
-	struct device_node *dev_node = muxc->dev->of_node;
-	struct device_node *mux_node, *child = NULL;
+	struct fwnode_handle *dev_node = dev_fwnode(muxc->dev);
+	struct fwnode_handle *mux_node, *child = NULL;
 	u32 reg;
 	int ret;
 
-	if (!dev_node)
+	if (!is_of_node(dev_node) && !is_software_node(dev_node))
 		return NULL;
 
 	if (muxc->arbitrator)
-		mux_node = of_get_child_by_name(dev_node, "i2c-arb");
+		mux_node = fwnode_get_named_child_node(dev_node, "i2c-arb");
 	else if (muxc->gate)
-		mux_node = of_get_child_by_name(dev_node, "i2c-gate");
+		mux_node = fwnode_get_named_child_node(dev_node, "i2c-gate");
 	else
-		mux_node = of_get_child_by_name(dev_node, "i2c-mux");
+		mux_node = fwnode_get_named_child_node(dev_node, "i2c-mux");
 
 	if (mux_node) {
-		/* A "reg" property indicates an old-style DT entry */
-		if (!of_property_read_u32(mux_node, "reg", &reg)) {
-			of_node_put(mux_node);
+		/* A "reg" property indicates an old-style firmware entry. */
+		if (!fwnode_property_read_u32(mux_node, "reg", &reg)) {
+			fwnode_handle_put(mux_node);
 			mux_node = NULL;
 		}
 	}
 
 	if (!mux_node)
-		mux_node = of_node_get(dev_node);
+		mux_node = fwnode_handle_get(dev_node);
 	else if (muxc->arbitrator || muxc->gate)
-		child = of_node_get(mux_node);
+		child = fwnode_handle_get(mux_node);
 
 	if (!child) {
-		for_each_child_of_node(mux_node, child) {
-			ret = of_property_read_u32(child, "reg", &reg);
+		fwnode_for_each_child_node(mux_node, child) {
+			ret = fwnode_property_read_u32(child, "reg", &reg);
 			if (ret)
 				continue;
 			if (chan_id == reg)
@@ -305,7 +306,7 @@ i2c_mux_get_channel_node(struct i2c_mux_core *muxc, u32 chan_id)
 		}
 	}
 
-	of_node_put(mux_node);
+	fwnode_handle_put(mux_node);
 	return child;
 }
 
@@ -368,11 +369,9 @@ int i2c_mux_add_adapter(struct i2c_mux_core *muxc,
 	else
 		priv->adap.lock_ops = &i2c_parent_lock_ops;
 
-	/*
-	 * Try to populate the mux adapter's of_node, expands to
-	 * nothing if !CONFIG_OF.
-	 */
-	priv->adap.dev.of_node = i2c_mux_get_channel_node(muxc, chan_id);
+	/* Associate the mux adapter with its OF or software-node channel. */
+	device_set_node(&priv->adap.dev,
+			i2c_mux_get_channel_node(muxc, chan_id));
 
 	/*
 	 * Associate the mux channel with an ACPI node.
@@ -416,7 +415,7 @@ int i2c_mux_add_adapter(struct i2c_mux_core *muxc,
 	return 0;
 
 err_free_priv:
-	of_node_put(priv->adap.dev.of_node);
+	fwnode_handle_put(dev_fwnode(&priv->adap.dev));
 	kfree(priv);
 	return ret;
 }
@@ -429,7 +428,7 @@ void i2c_mux_del_adapters(struct i2c_mux_core *muxc)
 	while (muxc->num_adapters) {
 		struct i2c_adapter *adap = muxc->adapter[--muxc->num_adapters];
 		struct i2c_mux_priv *priv = adap->algo_data;
-		struct device_node *np = adap->dev.of_node;
+		struct fwnode_handle *fwnode = dev_fwnode(&adap->dev);
 
 		muxc->adapter[muxc->num_adapters] = NULL;
 
@@ -439,7 +438,7 @@ void i2c_mux_del_adapters(struct i2c_mux_core *muxc)
 
 		sysfs_remove_link(&priv->adap.dev.kobj, "mux_device");
 		i2c_del_adapter(adap);
-		of_node_put(np);
+		fwnode_handle_put(fwnode);
 		kfree(priv);
 	}
 }
-- 
2.50.1 (Apple Git-155)