Angel Pons | 56c1c4d | 2023-03-22 13:25:09 +0100 | [diff] [blame^] | 1 | /* SPDX-License-Identifier: GPL-2.0-only */ |
| 2 | |
| 3 | #include <console/console.h> |
| 4 | #include <string.h> |
| 5 | #include <types.h> |
| 6 | |
| 7 | #include "ec.h" |
| 8 | #include "mainboard.h" |
| 9 | #include "vpd.h" |
| 10 | |
| 11 | const union emi_eeprom_vpd *get_emi_eeprom_vpd(void) |
| 12 | { |
| 13 | static union emi_eeprom_vpd vpd = {0}; |
| 14 | |
| 15 | /* Check if cached VPD is valid */ |
| 16 | if (vpd.header.revision == VPD_LATEST_REVISION) |
| 17 | return &vpd; |
| 18 | |
| 19 | ec_emi_read(vpd.raw, EMI_0_IO_BASE_ADDR, 0, 0, sizeof(vpd.raw)); |
| 20 | |
| 21 | /* If the magic value doesn't match, consider EEPROM VPD unreliable */ |
| 22 | if (vpd.header.magic != VPD_MAGIC) { |
| 23 | printk(BIOS_WARNING, "Atlas VPD: Bad magic value, using fallback defaults\n"); |
| 24 | vpd.header.revision = 0; |
| 25 | } else { |
| 26 | printk(BIOS_DEBUG, "Atlas VPD: Got revision %u from EC\n", vpd.header.revision); |
| 27 | } |
| 28 | |
| 29 | /* |
| 30 | * For backwards compatibility, if the VPD from the EC is an older |
| 31 | * version, uprev it to the latest version coreboot knows about by |
| 32 | * filling in the remaining fields with default values. Should the |
| 33 | * EC provide a newer VPD revision, coreboot would downgrade it to |
| 34 | * the latest version it knows about as the VPD layout is designed |
| 35 | * to be backwards compatible. |
| 36 | * |
| 37 | * Whenever the value of `VPD_LATEST_REVISION` is incremented, add |
| 38 | * a new `case` label just before the `default` label that matches |
| 39 | * the second latest revision to initialise the newly-added fields |
| 40 | * of the VPD structure with a reasonable fallback value. Note the |
| 41 | * intentional falling through. |
| 42 | */ |
| 43 | switch (vpd.header.revision) { |
| 44 | case 0: |
| 45 | memset(vpd.raw, 0, sizeof(vpd.raw)); |
| 46 | vpd.header.magic = VPD_MAGIC; |
| 47 | vpd.serial_number[0] = '\0'; |
| 48 | vpd.part_number[0] = '\0'; |
| 49 | vpd.profile = ATLAS_PROF_UNPROGRAMMED; |
| 50 | __fallthrough; |
| 51 | default: |
| 52 | /* Ensure serial numbers are NULL-terminated, update revision last */ |
| 53 | vpd.serial_number[ATLAS_SN_PN_LENGTH - 1] = '\0'; |
| 54 | vpd.part_number[ATLAS_SN_PN_LENGTH - 1] = '\0'; |
| 55 | vpd.header.revision = VPD_LATEST_REVISION; |
| 56 | break; |
| 57 | } |
| 58 | |
| 59 | return &vpd; |
| 60 | } |