Device Tree channel nodes are associated with the adapters created by i2c-mux, but equivalent software-node descriptions are not.
Find the software-node child whose reg value matches the channel and assign it to the new adapter. Keep a reference for the adapter lifetime so downstream clients can find the channel by firmware node. Signed-off-by: Ahmad Byagowi <[email protected]> --- drivers/i2c/i2c-mux.c | 71 +++++++++++++++++++++++++++++++++++++++++-- 1 file changed, 69 insertions(+), 2 deletions(-) diff --git a/drivers/i2c/i2c-mux.c b/drivers/i2c/i2c-mux.c index 681a201c239b..040284236275 100644 --- a/drivers/i2c/i2c-mux.c +++ b/drivers/i2c/i2c-mux.c @@ -20,11 +20,13 @@ */ #include <linux/acpi.h> +#include <linux/err.h> #include <linux/i2c.h> #include <linux/i2c-mux.h> #include <linux/kernel.h> #include <linux/module.h> #include <linux/of.h> +#include <linux/property.h> #include <linux/slab.h> #include <linux/sysfs.h> @@ -33,6 +35,7 @@ struct i2c_mux_priv { struct i2c_adapter adap; struct i2c_algorithm algo; struct i2c_mux_core *muxc; + struct fwnode_handle *swnode; u32 chan_id; }; @@ -264,10 +267,60 @@ static const struct i2c_lock_operations i2c_parent_lock_ops = { .unlock_bus = i2c_parent_unlock_bus, }; +static struct fwnode_handle * +i2c_mux_get_channel_swnode(struct i2c_mux_core *muxc, u32 chan_id) +{ + struct fwnode_handle *dev_node = dev_fwnode(muxc->dev); + struct fwnode_handle *mux_node, *child = NULL; + u32 reg; + + /* A software node supplementing ACPI is the secondary fwnode. */ + if (!is_software_node(dev_node)) { + if (IS_ERR_OR_NULL(dev_node)) + return NULL; + dev_node = dev_node->secondary; + } + if (!is_software_node(dev_node)) + return NULL; + + if (muxc->arbitrator) + mux_node = fwnode_get_named_child_node(dev_node, "i2c-arb"); + else if (muxc->gate) + mux_node = fwnode_get_named_child_node(dev_node, "i2c-gate"); + else + mux_node = fwnode_get_named_child_node(dev_node, "i2c-mux"); + + if (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 = fwnode_handle_get(dev_node); + else if (muxc->arbitrator || muxc->gate) + child = fwnode_handle_get(mux_node); + + if (!child) { + fwnode_for_each_child_node(mux_node, child) { + if (fwnode_property_read_u32(child, "reg", ®)) + continue; + if (chan_id == reg) + break; + } + } + + fwnode_handle_put(mux_node); + return child; +} + int i2c_mux_add_adapter(struct i2c_mux_core *muxc, u32 force_nr, u32 chan_id) { struct i2c_adapter *parent = muxc->parent; + struct fwnode_handle *channel_node = NULL; struct i2c_mux_priv *priv; char symlink_name[20]; int ret; @@ -324,8 +377,8 @@ int i2c_mux_add_adapter(struct i2c_mux_core *muxc, priv->adap.lock_ops = &i2c_parent_lock_ops; /* - * Try to populate the mux adapter's of_node, expands to - * nothing if !CONFIG_OF. + * Associate the mux adapter with its DT or software-node channel. + * DT support expands to nothing if !CONFIG_OF. */ if (muxc->dev->of_node) { struct device_node *dev_node = muxc->dev->of_node; @@ -364,6 +417,8 @@ int i2c_mux_add_adapter(struct i2c_mux_core *muxc, priv->adap.dev.of_node = child; of_node_put(mux_node); + } else { + channel_node = i2c_mux_get_channel_swnode(muxc, chan_id); } /* @@ -374,6 +429,16 @@ int i2c_mux_add_adapter(struct i2c_mux_core *muxc, ACPI_COMPANION(muxc->dev), chan_id); + if (channel_node) { + ret = device_add_software_node(&priv->adap.dev, + to_software_node(channel_node)); + if (!ret) + priv->swnode = channel_node; + fwnode_handle_put(channel_node); + if (ret) + goto err_free_priv; + } + if (force_nr) { priv->adap.nr = force_nr; ret = i2c_add_numbered_adapter(&priv->adap); @@ -408,6 +473,7 @@ int i2c_mux_add_adapter(struct i2c_mux_core *muxc, return 0; err_free_priv: + device_remove_software_node(&priv->adap.dev); kfree(priv); return ret; } @@ -430,6 +496,7 @@ void i2c_mux_del_adapters(struct i2c_mux_core *muxc) sysfs_remove_link(&priv->adap.dev.kobj, "mux_device"); i2c_del_adapter(adap); + fwnode_handle_put(priv->swnode); of_node_put(np); kfree(priv); } -- 2.50.1 (Apple Git-155)
