blob: d77c987fda9cd1270022a657b37aa61ec870b249 [file] [log] [blame]
// SPDX-License-Identifier: GPL-2.0-only
* ACPI helpers for the MDIO (Ethernet PHY) API
* This file provides helper functions for extracting PHY device information
* out of the ACPI ASL and using it to populate an mii_bus.
#include <linux/acpi.h>
#include <linux/acpi_mdio.h>
#include <linux/bits.h>
#include <linux/dev_printk.h>
#include <linux/fwnode_mdio.h>
#include <linux/module.h>
#include <linux/types.h>
MODULE_AUTHOR("Calvin Johnson <>");
* acpi_mdiobus_register - Register mii_bus and create PHYs from the ACPI ASL.
* @mdio: pointer to mii_bus structure
* @fwnode: pointer to fwnode of MDIO bus. This fwnode is expected to represent
* an ACPI device object corresponding to the MDIO bus and its children are
* expected to correspond to the PHY devices on that bus.
* This function registers the mii_bus structure and registers a phy_device
* for each child node of @fwnode.
int acpi_mdiobus_register(struct mii_bus *mdio, struct fwnode_handle *fwnode)
struct fwnode_handle *child;
u32 addr;
int ret;
/* Mask out all PHYs from auto probing. */
mdio->phy_mask = GENMASK(31, 0);
ret = mdiobus_register(mdio);
if (ret)
return ret;
ACPI_COMPANION_SET(&mdio->dev, to_acpi_device_node(fwnode));
/* Loop over the child nodes and register a phy_device for each PHY */
fwnode_for_each_child_node(fwnode, child) {
ret = acpi_get_local_address(ACPI_HANDLE_FWNODE(child), &addr);
if (ret || addr >= PHY_MAX_ADDR)
ret = fwnode_mdiobus_register_phy(mdio, child, addr);
if (ret == -ENODEV)
"MDIO device at address %d is missing.\n",
return 0;