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 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 */ 30 int 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 } 58 EXPORT_SYMBOL(acpi_mdiobus_register); 59