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/*
* This file is part of the coreboot project.
*
* Copyright 2018 MediaTek 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 <assert.h>
#include <boardid.h>
#include <soc/auxadc.h>
#include <stddef.h>
static uint32_t get_index(unsigned int channel, uint32_t *cached_id)
{
static const int voltages[] = {
/* ID : Voltage (unit: uV) */
/* 0 : */ 74000,
/* 1 : */ 212000,
/* 2 : */ 319000,
/* 3 : */ 429000,
/* 4 : */ 542000,
/* 5 : */ 666000,
/* 6 : */ 781000,
/* 7 : */ 900000,
/* 8 : */ 1023000,
/* 9 : */ 1137000,
/* 10 : */ 1240000,
/* 11 : */ 1343000,
/* 12 : */ 1457000
};
uint32_t id;
if (*cached_id != BOARD_ID_INIT)
return *cached_id;
int value = auxadc_get_voltage(channel);
/* Find the closest voltage */
for (id = 0; id < ARRAY_SIZE(voltages) - 1; id++)
if (value < (voltages[id] + voltages[id + 1]) / 2)
break;
const int tolerance = 10000; /* 10,000 uV */
assert(ABS(value - voltages[id]) < tolerance);
*cached_id = id;
return id;
}
uint32_t board_id(void)
{
static uint32_t cached_board_id = BOARD_ID_INIT;
return get_index(4, &cached_board_id);
}
uint32_t ram_code(void)
{
static uint32_t cached_ram_code = BOARD_ID_INIT;
return get_index(3, &cached_ram_code);
}
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