Duncan Laurie | 57d5e47 | 2019-03-01 15:40:48 +0800 | [diff] [blame] | 1 | /* |
| 2 | * This file is part of the coreboot project. |
| 3 | * |
| 4 | * Copyright 2019 Google LLC |
| 5 | * |
| 6 | * This program is free software; you can redistribute it and/or |
| 7 | * modify it under the terms of the GNU General Public License as |
| 8 | * published by the Free Software Foundation; version 2 of |
| 9 | * the License. |
| 10 | * |
| 11 | * This program is distributed in the hope that it will be useful, |
| 12 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 13 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 14 | * GNU General Public License for more details. |
| 15 | */ |
| 16 | |
| 17 | /* |
| 18 | * The Realtek r8152 driver in the Linux kernel supports a MAC address |
Simon Glass | aa21574 | 2019-05-16 14:51:51 -0600 | [diff] [blame^] | 19 | * dock pass-through feature which can result in the dock ethernet port |
| 20 | * using the same MAC address that is assigned to the internal NIC. This |
| 21 | * is done by calling an ACPI method at \_SB.AMAC() which returns a |
| 22 | * formatted string (as a buffer) containing the MAC address for the |
| 23 | * dock to use. |
Duncan Laurie | 57d5e47 | 2019-03-01 15:40:48 +0800 | [diff] [blame] | 24 | * |
| 25 | * The Linux kernel implementation can be found at |
| 26 | * drivers/net/usb/r8152.c:vendor_mac_passthru_addr_read() |
| 27 | * |
| 28 | * For Chrome OS, the policy which controls where the dock MAC address |
Simon Glass | aa21574 | 2019-05-16 14:51:51 -0600 | [diff] [blame^] | 29 | * comes from is written into RW_VPD property "dock_passthrough": |
Duncan Laurie | 57d5e47 | 2019-03-01 15:40:48 +0800 | [diff] [blame] | 30 | * |
| 31 | * "dock_mac" or empty: Use MAC address from RO_VPD value "dock_mac" |
| 32 | * "ethernet_mac0": Use MAC address from RO_VPD value "ethernet_mac0" |
| 33 | * "builtin": existing dock MAC address (return nothing) |
| 34 | */ |
| 35 | |
| 36 | Scope (\_SB) |
| 37 | { |
| 38 | Method (AMAC, 0, Serialized) |
| 39 | { |
| 40 | /* Format expected by the Linux kernel r8152 driver */ |
| 41 | Name (MACA, "_AUXMAC_#XXXXXXXXXXXX#") |
| 42 | |
Simon Glass | aa21574 | 2019-05-16 14:51:51 -0600 | [diff] [blame^] | 43 | /* Get "dock_passthrough" value from RW_VPD */ |
| 44 | Local0 = \VPD.VPDF ("RW", "dock_passthrough") |
Duncan Laurie | 57d5e47 | 2019-03-01 15:40:48 +0800 | [diff] [blame] | 45 | |
Duncan Laurie | 643daed | 2019-05-08 15:09:29 -0600 | [diff] [blame] | 46 | Local1 = Zero |
Duncan Laurie | 57d5e47 | 2019-03-01 15:40:48 +0800 | [diff] [blame] | 47 | Switch (ToString (Local0)) |
| 48 | { |
| 49 | Case ("ethernet_mac0") { |
| 50 | Local1 = \VPD.VPDF ("RO", "ethernet_mac0") |
| 51 | } |
| 52 | Case ("builtin") { |
| 53 | Return (Zero) |
| 54 | } |
| 55 | /* "dock_mac" or policy not found. */ |
| 56 | Default { |
| 57 | Local1 = \VPD.VPDF ("RO", "dock_mac") |
| 58 | } |
| 59 | } |
Duncan Laurie | 643daed | 2019-05-08 15:09:29 -0600 | [diff] [blame] | 60 | If (Local1 == Zero) { |
Duncan Laurie | 57d5e47 | 2019-03-01 15:40:48 +0800 | [diff] [blame] | 61 | Return (Zero) |
| 62 | } |
| 63 | Printf ("MAC address returned from VPD: %o", Local1) |
| 64 | |
| 65 | /* Verify MAC address format is AA:BB:CC:DD:EE:FF */ |
| 66 | For (Local3 = 2, Local3 < 17, Local3 += 3) { |
| 67 | If (ToString (DerefOf (Local1[Local3])) != ":") { |
| 68 | Printf ("Invalid MAC address byte %o", Local3) |
| 69 | Return (Zero) |
| 70 | } |
| 71 | } |
| 72 | |
| 73 | /* Convert MAC address into format specified by MACA */ |
| 74 | Local2 = ToBuffer (MACA) |
| 75 | Local4 = 0 /* First MAC address byte in input buffer */ |
| 76 | Local5 = 9 /* First MAC address byte in output buffer */ |
| 77 | For (Local3 = 0, Local3 < 6, Local3++) { |
| 78 | Local2[Local5] = DerefOf (Local1[Local4]) |
| 79 | Local2[Local5 + 1] = DerefOf (Local1[Local4 + 1]) |
| 80 | Local5 += 2 |
| 81 | Local4 += 3 /* Skip ":" in address from VPD */ |
| 82 | } |
| 83 | |
| 84 | Printf ("AMAC = %o", ToString (Local2)) |
Duncan Laurie | 8d8cead | 2019-03-07 22:24:43 +0800 | [diff] [blame] | 85 | Return (Local2) |
Duncan Laurie | 57d5e47 | 2019-03-01 15:40:48 +0800 | [diff] [blame] | 86 | } |
| 87 | } |