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 attach it to the new adapter. Preserve an ACPI primary node when present and extend I2C firmware-node adapter lookup to match the attached secondary node. Track attachment ownership so failure cleanup cannot detach a pre-existing node. Keep the owned node attached through child-client removal, then release its reference after adapter deletion. Signed-off-by: Ahmad Byagowi <[email protected]> --- drivers/i2c/i2c-core-base.c | 24 +++++++++--- drivers/i2c/i2c-mux.c | 77 ++++++++++++++++++++++++++++++++++++- 2 files changed, 93 insertions(+), 8 deletions(-) diff --git a/drivers/i2c/i2c-core-base.c b/drivers/i2c/i2c-core-base.c index 3ec04787a737..f39575ee0244 100644 --- a/drivers/i2c/i2c-core-base.c +++ b/drivers/i2c/i2c-core-base.c @@ -1876,12 +1876,22 @@ int devm_i2c_add_adapter(struct device *dev, struct i2c_adapter *adapter) } EXPORT_SYMBOL_GPL(devm_i2c_add_adapter); -static int i2c_dev_or_parent_fwnode_match(struct device *dev, const void *data) +static bool i2c_device_match_fwnode(struct device *dev, const void *data) { + struct fwnode_handle *fwnode = dev_fwnode(dev); + if (device_match_fwnode(dev, data)) + return true; + + return !IS_ERR_OR_NULL(fwnode) && fwnode->secondary == data; +} + +static int i2c_dev_or_parent_fwnode_match(struct device *dev, const void *data) +{ + if (i2c_device_match_fwnode(dev, data)) return 1; - if (dev->parent && device_match_fwnode(dev->parent, data)) + if (dev->parent && i2c_device_match_fwnode(dev->parent, data)) return 1; return 0; @@ -1891,8 +1901,9 @@ static int i2c_dev_or_parent_fwnode_match(struct device *dev, const void *data) * i2c_find_adapter_by_fwnode() - find an i2c_adapter for the fwnode * @fwnode: &struct fwnode_handle corresponding to the &struct i2c_adapter * - * Look up and return the &struct i2c_adapter corresponding to the @fwnode. - * If no adapter can be found, or @fwnode is NULL, this returns NULL. + * Look up and return the &struct i2c_adapter corresponding to the @fwnode, + * including a secondary firmware node. If no adapter can be found, or + * @fwnode is NULL, this returns NULL. * * The user must call put_device(&adapter->dev) once done with the i2c adapter. */ @@ -1922,8 +1933,9 @@ EXPORT_SYMBOL(i2c_find_adapter_by_fwnode); * @fwnode: &struct fwnode_handle corresponding to the &struct i2c_adapter * * Look up and return the &struct i2c_adapter corresponding to the @fwnode, - * and increment the adapter module's use count. If no adapter can be found, - * or @fwnode is NULL, this returns NULL. + * including a secondary firmware node, and increment the adapter module's + * use count. If no adapter can be found, or @fwnode is NULL, this returns + * NULL. * * The user must call i2c_put_adapter(adapter) once done with the i2c adapter. * Note that this is different from i2c_find_adapter_by_node(). diff --git a/drivers/i2c/i2c-mux.c b/drivers/i2c/i2c-mux.c index 681a201c239b..3bca123907b3 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 +473,8 @@ int i2c_mux_add_adapter(struct i2c_mux_core *muxc, return 0; err_free_priv: + if (priv->swnode) + device_remove_software_node(&priv->adap.dev); kfree(priv); return ret; } @@ -429,7 +496,13 @@ void i2c_mux_del_adapters(struct i2c_mux_core *muxc) sysfs_remove_link(&muxc->dev->kobj, symlink_name); sysfs_remove_link(&priv->adap.dev.kobj, "mux_device"); + /* + * Keep the software node through child removal. The adapter + * device is cleared on deletion, so release the software-node + * attachment reference via the saved handle afterwards. + */ i2c_del_adapter(adap); + fwnode_handle_put(priv->swnode); of_node_put(np); kfree(priv); } -- 2.50.1 (Apple Git-155)
