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(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); 50 if (ret || addr >= PHY_MAX_ADDR) 51 continue; 52 53 ret = fwnode_mdiobus_register_phy(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