From ff9abb51615c7eb4160a0b2222650a51a3c90bc2 Mon Sep 17 00:00:00 2001 From: Ahmad Byagowi Date: Mon, 7 Sep 2026 23:26:22 -0700 Subject: [PATCH] i2c: mux: Factor out channel node lookup 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 Reviewed-by: Andy Shevchenko Acked-by: Peter Rosin Signed-off-by: Andi Shyti Link: https://patch.msgid.link/adf12f66229d5faa0bc75571da1c3f53a1c81dd8.1788623619.git.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..d207f0e81807 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; + struct device_node *mux_node; + struct device_node *child; + u32 reg; + int ret; + + dev_node = dev_of_node(muxc->dev); + 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) + return mux_node; + + 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.