| /* |
| * 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; |
| } |