/* * This file is part of the coreboot project. * * Copyright 2014 Google Inc. * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; version 2 of the License. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. */ #include <boardid.h> #include <gpio.h> #include <console/console.h> #include <stdlib.h> /* * Storm boards dedicate to the board ID three GPIOs in tertiary mode: 29, 30 * and 68. On proto0 GPIO68 is used and tied low, so it reads as 'zero' by * gpio_base3_value(), whereas the other two pins are not connected * and read as 'two'. This results in gpio_base3_value() returning * 8 on proto0. * * Three tertitiary signals could represent 27 different values. To make * calculated board ID value continuous and starting at zero, offset the * calculated value by 19 (i.e. 27 - 8) and return modulo 27 of the offset * number. This results in proto0 returning zero as the board ID, the future * revisions will have the inputs configured to match the actual board * revision. */ static int board_id_value = -1; static uint8_t get_board_id(void) { uint8_t bid; gpio_t hw_rev_gpios[] = {[2] = 68, [1] = 30, [0] = 29}; /* 29 is LSB */ int offset = 19; bid = gpio_base3_value(hw_rev_gpios, ARRAY_SIZE(hw_rev_gpios)); bid = (bid + offset) % 27; printk(BIOS_INFO, "Board ID %d\n", bid); return bid; } uint8_t board_id(void) { if (board_id_value < 0) board_id_value = get_board_id(); return board_id_value; }