* [PATCH v7 2/3] i2c: mux: Factor out channel node lookup
2026-08-23 16:34 [PATCH v7 0/3] i2c: mux: Propagate software nodes to channel adapters Ahmad Byagowi
2026-08-23 16:34 ` [PATCH v7 1/3] i2c: mux: Fix channel node leak on adapter add failure Ahmad Byagowi
@ 2026-08-23 16:34 ` Ahmad Byagowi
2026-08-23 16:34 ` [PATCH v7 3/3] i2c: mux: Propagate software nodes to channel adapters Ahmad Byagowi
2 siblings, 0 replies; 4+ messages in thread
From: Ahmad Byagowi @ 2026-08-23 16:34 UTC (permalink / raw)
To: Andi Shyti
Cc: Peter Rosin, Jakub Kicinski, linux-i2c, linux-kernel, Ahmad Byagowi
Move the existing Device Tree channel-node lookup into a helper in
preparation for using generic firmware-node operations.
This is a pure refactoring with no functional change.
Signed-off-by: Ahmad Byagowi <ahmadexp@gmail.com>
---
drivers/i2c/i2c-mux.c | 84 +++++++++++++++++++++++--------------------
1 file changed, 46 insertions(+), 38 deletions(-)
diff --git a/drivers/i2c/i2c-mux.c b/drivers/i2c/i2c-mux.c
index 68a4c34b5987..a8b94b97a725 100644
--- a/drivers/i2c/i2c-mux.c
+++ b/drivers/i2c/i2c-mux.c
@@ -264,6 +264,51 @@ static const struct i2c_lock_operations i2c_parent_lock_ops = {
.unlock_bus = i2c_parent_unlock_bus,
};
+static struct device_node *
+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;
+ u32 reg;
+ int ret;
+
+ if (!dev_node)
+ return NULL;
+
+ if (muxc->arbitrator)
+ mux_node = of_get_child_by_name(dev_node, "i2c-arb");
+ else if (muxc->gate)
+ mux_node = of_get_child_by_name(dev_node, "i2c-gate");
+ else
+ mux_node = of_get_child_by_name(dev_node, "i2c-mux");
+
+ if (mux_node) {
+ /* A "reg" property indicates an old-style DT entry */
+ if (!of_property_read_u32(mux_node, "reg", ®)) {
+ of_node_put(mux_node);
+ mux_node = NULL;
+ }
+ }
+
+ if (!mux_node)
+ mux_node = of_node_get(dev_node);
+ else if (muxc->arbitrator || muxc->gate)
+ child = of_node_get(mux_node);
+
+ if (!child) {
+ for_each_child_of_node(mux_node, child) {
+ ret = of_property_read_u32(child, "reg", ®);
+ if (ret)
+ continue;
+ if (chan_id == reg)
+ break;
+ }
+ }
+
+ of_node_put(mux_node);
+ return child;
+}
+
int i2c_mux_add_adapter(struct i2c_mux_core *muxc,
u32 force_nr, u32 chan_id)
{
@@ -327,44 +372,7 @@ int i2c_mux_add_adapter(struct i2c_mux_core *muxc,
* Try to populate the mux adapter's of_node, expands to
* nothing if !CONFIG_OF.
*/
- if (muxc->dev->of_node) {
- struct device_node *dev_node = muxc->dev->of_node;
- struct device_node *mux_node, *child = NULL;
- u32 reg;
-
- if (muxc->arbitrator)
- mux_node = of_get_child_by_name(dev_node, "i2c-arb");
- else if (muxc->gate)
- mux_node = of_get_child_by_name(dev_node, "i2c-gate");
- else
- mux_node = of_get_child_by_name(dev_node, "i2c-mux");
-
- if (mux_node) {
- /* A "reg" property indicates an old-style DT entry */
- if (!of_property_read_u32(mux_node, "reg", ®)) {
- of_node_put(mux_node);
- mux_node = NULL;
- }
- }
-
- if (!mux_node)
- mux_node = of_node_get(dev_node);
- else if (muxc->arbitrator || muxc->gate)
- child = of_node_get(mux_node);
-
- if (!child) {
- for_each_child_of_node(mux_node, child) {
- ret = of_property_read_u32(child, "reg", ®);
- if (ret)
- continue;
- if (chan_id == reg)
- break;
- }
- }
-
- priv->adap.dev.of_node = child;
- of_node_put(mux_node);
- }
+ priv->adap.dev.of_node = i2c_mux_get_channel_node(muxc, chan_id);
/*
* Associate the mux channel with an ACPI node.
--
2.50.1 (Apple Git-155)
^ permalink raw reply [flat|nested] 4+ messages in thread* [PATCH v7 3/3] i2c: mux: Propagate software nodes to channel adapters
2026-08-23 16:34 [PATCH v7 0/3] i2c: mux: Propagate software nodes to channel adapters Ahmad Byagowi
2026-08-23 16:34 ` [PATCH v7 1/3] i2c: mux: Fix channel node leak on adapter add failure Ahmad Byagowi
2026-08-23 16:34 ` [PATCH v7 2/3] i2c: mux: Factor out channel node lookup Ahmad Byagowi
@ 2026-08-23 16:34 ` Ahmad Byagowi
2 siblings, 0 replies; 4+ messages in thread
From: Ahmad Byagowi @ 2026-08-23 16:34 UTC (permalink / raw)
To: Andi Shyti
Cc: Peter Rosin, Jakub Kicinski, linux-i2c, linux-kernel, 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@gmail.com>
---
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", ®)) {
- of_node_put(mux_node);
+ /* A "reg" property indicates an old-style firmware entry. */
+ if (!fwnode_property_read_u32(mux_node, "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", ®);
+ fwnode_for_each_child_node(mux_node, child) {
+ ret = fwnode_property_read_u32(child, "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)
^ permalink raw reply [flat|nested] 4+ messages in thread