I would like the "nxp,sja1110a" driver, in the configuration below, to be able to probe the drivers for "nxp,sja1110-base-t1-mdio" and for "nxp,sja1110-base-tx-mdio" via mfd_add_devices(): ethernet-switch@0 { compatible = "nxp,sja1110a"; mdios { mdio@0 { compatible = "nxp,sja1110-base-t1-mdio"; }; mdio@1 { compatible = "nxp,sja1110-base-tx-mdio"; }; }; }; This isn't currently possible, because mfd assumes that the parent OF node ("mdios") == OF node of the parent ("ethernet-switch@0"), which in this case isn't true, and as it searches through the children of "ethernet-switch@0", it finds no MDIO bus to probe. Cc: Lee Jones Signed-off-by: Vladimir Oltean --- drivers/mfd/mfd-core.c | 11 +++++++++-- include/linux/mfd/core.h | 7 +++++++ 2 files changed, 16 insertions(+), 2 deletions(-) diff --git a/drivers/mfd/mfd-core.c b/drivers/mfd/mfd-core.c index 7d14a1e7631e..e0b7f93a2654 100644 --- a/drivers/mfd/mfd-core.c +++ b/drivers/mfd/mfd-core.c @@ -181,8 +181,14 @@ static int mfd_add_device(struct device *parent, int id, if (ret < 0) goto fail_res; - if (IS_ENABLED(CONFIG_OF) && parent->of_node && cell->of_compatible) { - for_each_child_of_node(parent->of_node, np) { + if (IS_ENABLED(CONFIG_OF)) { + const struct device_node *parent_of_node; + + parent_of_node = cell->parent_of_node ?: parent->of_node; + if (!parent_of_node || !cell->of_compatible) + goto skip_of; + + for_each_child_of_node(parent_of_node, np) { if (of_device_is_compatible(np, cell->of_compatible)) { /* Skip 'disabled' devices */ if (!of_device_is_available(np)) { @@ -213,6 +219,7 @@ static int mfd_add_device(struct device *parent, int id, cell->name, platform_id); } +skip_of: mfd_acpi_add_device(cell, pdev); if (cell->pdata_size) { diff --git a/include/linux/mfd/core.h b/include/linux/mfd/core.h index faeea7abd688..2e94ea376125 100644 --- a/include/linux/mfd/core.h +++ b/include/linux/mfd/core.h @@ -81,6 +81,13 @@ struct mfd_cell { /* Software node for the device. */ const struct software_node *swnode; + /* + * Parent OF node of the device, if different from the OF node + * of the MFD parent (e.g. there is at least one more hierarchical + * level between them) + */ + const struct device_node *parent_of_node; + /* * Device Tree compatible string * See: Documentation/devicetree/usage-model.rst Chapter 2.2 for details -- 2.34.1