1// SPDX-License-Identifier: GPL-2.0-only
 2/*
 3 * ACPI helpers for the MDIO (Ethernet PHY) API
 4 *
 5 * This file provides helper functions for extracting PHY device information
 6 * out of the ACPI ASL and using it to populate an mii_bus.
 7 */
 8
 9#include <linux/acpi.h>
10#include <linux/acpi_mdio.h>
11#include <linux/bits.h>
12#include <linux/dev_printk.h>
13#include <linux/fwnode_mdio.h>
14#include <linux/module.h>
15#include <linux/types.h>
16
17MODULE_AUTHOR("Calvin Johnson <calvin.johnson@oss.nxp.com>");
18MODULE_LICENSE("GPL");
19
20/**
21 * acpi_mdiobus_register - Register mii_bus and create PHYs from the ACPI ASL.
22 * @mdio: pointer to mii_bus structure
23 * @fwnode: pointer to fwnode of MDIO bus. This fwnode is expected to represent
24 * an ACPI device object corresponding to the MDIO bus and its children are
25 * expected to correspond to the PHY devices on that bus.
26 *
27 * This function registers the mii_bus structure and registers a phy_device
28 * for each child node of @fwnode.
29 */
30int acpi_mdiobus_register(struct mii_bus *mdio, struct fwnode_handle *fwnode)
31{
32	struct fwnode_handle *child;
33	u32 addr;
34	int ret;
35
36	/* Mask out all PHYs from auto probing. */
37	mdio->phy_mask = GENMASK(31, 0);
38	ret = mdiobus_register(mdio);
39	if (ret)
40		return ret;
41
42	ACPI_COMPANION_SET(&mdio->dev, to_acpi_device_node(fwnode));
43
44	/* Loop over the child nodes and register a phy_device for each PHY */
45	fwnode_for_each_child_node(fwnode, child) {
46		ret = acpi_get_local_address(ACPI_HANDLE_FWNODE(child), &addr);
47		if (ret || addr >= PHY_MAX_ADDR)
48			continue;
49
50		ret = fwnode_mdiobus_register_phy(mdio, child, addr);
51		if (ret == -ENODEV)
52			dev_err(&mdio->dev,
53				"MDIO device at address %d is missing.\n",
54				addr);
55	}
56	return 0;
57}
58EXPORT_SYMBOL(acpi_mdiobus_register);