| /* |
| * This file is part of the coreboot project. |
| * |
| * Copyright 2016 Rockchip 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 <console/console.h> |
| #include <stdlib.h> |
| #include <soc/saradc.h> |
| |
| /* |
| * ID info: |
| * ID : Volts : ADC value : Bucket |
| * == ===== ========= =========== |
| * 0 : 0.074V: 42 : 0 - 81 |
| * 1 : 0.211V: 120 : 82 - 150 |
| * 2 : 0.319V: 181 : 151 - 211 |
| * 3 : 0.427V: 242 : 212 - 274 |
| * 4 : 0.542V: 307 : 275 - 342 |
| * 5 : 0.666V: 378 : 343 - 411 |
| * 6 : 0.781V: 444 : 412 - 477 |
| * 7 : 0.900V: 511 : 478 - 545 |
| * 8 : 1.023V: 581 : 546 - 613 |
| * 9 : 1.137V: 646 : 614 - 675 |
| * 10 : 1.240V: 704 : 676 - 733 |
| * 11 : 1.343V: 763 : 734 - 795 |
| * 12 : 1.457V: 828 : 796 - 861 |
| * 13 : 1.576V: 895 : 862 - 925 |
| * 14 : 1.684V: 956 : 926 - 989 |
| * 15 : 1.800V: 1023 : 990 - 1023 |
| */ |
| static const int id_readings[] = { 81, 150, 211, 274, 342, 411, 477, 545, |
| 613, 675, 733, 795, 861, 925, 989, 1023 }; |
| _Static_assert(ARRAY_SIZE(id_readings) == 16, "Yo' messed up da table, bruh!"); |
| static int cached_board_id = -1; |
| static int cached_ram_id = -1; |
| |
| static uint32_t get_index(uint32_t channel, int *cached_id) |
| { |
| int i; |
| int adc_reading; |
| |
| if (*cached_id != -1) |
| return *cached_id; |
| |
| adc_reading = get_saradc_value(channel); |
| for (i = 0; i < ARRAY_SIZE(id_readings); i++) { |
| if (adc_reading <= id_readings[i]) { |
| printk(BIOS_DEBUG, "ADC reading %d, ID %d\n", |
| adc_reading, i); |
| *cached_id = i; |
| return i; |
| } |
| } |
| |
| die("Read impossible value ( > 1023) from 10-bit ADC!"); |
| } |
| |
| uint8_t board_id(void) |
| { |
| return get_index(1, &cached_board_id); |
| } |
| |
| uint32_t ram_code(void) |
| { |
| return get_index(0, &cached_ram_id); |
| } |
