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 | |
17 | MODULE_AUTHOR("Calvin Johnson <calvin.johnson@oss.nxp.com>" ); |
18 | MODULE_LICENSE("GPL" ); |
19 | MODULE_DESCRIPTION("ACPI MDIO bus (Ethernet PHY) accessors" ); |
20 | |
21 | /** |
22 | * __acpi_mdiobus_register - Register mii_bus and create PHYs from the ACPI ASL. |
23 | * @mdio: pointer to mii_bus structure |
24 | * @fwnode: pointer to fwnode of MDIO bus. This fwnode is expected to represent |
25 | * @owner: module owning this @mdio object. |
26 | * an ACPI device object corresponding to the MDIO bus and its children are |
27 | * expected to correspond to the PHY devices on that bus. |
28 | * |
29 | * This function registers the mii_bus structure and registers a phy_device |
30 | * for each child node of @fwnode. |
31 | */ |
32 | int __acpi_mdiobus_register(struct mii_bus *mdio, struct fwnode_handle *fwnode, |
33 | struct module *owner) |
34 | { |
35 | struct fwnode_handle *child; |
36 | u32 addr; |
37 | int ret; |
38 | |
39 | /* Mask out all PHYs from auto probing. */ |
40 | mdio->phy_mask = GENMASK(31, 0); |
41 | ret = __mdiobus_register(bus: mdio, owner); |
42 | if (ret) |
43 | return ret; |
44 | |
45 | ACPI_COMPANION_SET(&mdio->dev, to_acpi_device_node(fwnode)); |
46 | |
47 | /* Loop over the child nodes and register a phy_device for each PHY */ |
48 | fwnode_for_each_child_node(fwnode, child) { |
49 | ret = acpi_get_local_address(ACPI_HANDLE_FWNODE(child), addr: &addr); |
50 | if (ret || addr >= PHY_MAX_ADDR) |
51 | continue; |
52 | |
53 | ret = fwnode_mdiobus_register_phy(bus: mdio, child, addr); |
54 | if (ret == -ENODEV) |
55 | dev_err(&mdio->dev, |
56 | "MDIO device at address %d is missing.\n" , |
57 | addr); |
58 | } |
59 | return 0; |
60 | } |
61 | EXPORT_SYMBOL(__acpi_mdiobus_register); |
62 | |