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/* SPDX-License-Identifier: GPL-2.0-only */
#include <assert.h>
#include <boardid.h>
#include <console/console.h>
#include <soc/auxadc.h>
/* board_id is provided by ec/google/chromeec/ec_boardid.c */
#define ADC_LEVELS 15
enum {
RAM_ID_HIGH_CHANNEL = 4,
RAM_ID_LOW_CHANNEL = 3,
};
static const unsigned int ram_voltages[ADC_LEVELS] = {
/* ID : Voltage (unit: uV) */
[0] = 74300,
[1] = 211700,
[2] = 318800,
[3] = 428600,
[4] = 541700,
[5] = 665800,
[6] = 781400,
[7] = 900000,
[8] = 1023100,
[9] = 1137000,
[10] = 1240000,
[11] = 1342600,
[12] = 1457500,
[13] = 1575600,
[14] = 1683600,
};
static const unsigned int *adc_voltages[] = {
[RAM_ID_HIGH_CHANNEL] = ram_voltages,
[RAM_ID_LOW_CHANNEL] = ram_voltages,
};
static uint32_t get_adc_index(unsigned int channel)
{
unsigned int value = auxadc_get_voltage_uv(channel);
assert(channel < ARRAY_SIZE(adc_voltages));
const unsigned int *voltages = adc_voltages[channel];
assert(voltages);
/* Find the closest voltage */
uint32_t id;
for (id = 0; id < ADC_LEVELS - 1; id++)
if (value < (voltages[id] + voltages[id + 1]) / 2)
break;
printk(BIOS_DEBUG, "ADC[%u]: Raw value=%u ID=%u\n", channel, value, id);
return id;
}
uint32_t sku_id(void)
{
return 0;
}
uint32_t ram_code(void)
{
static uint32_t cached_ram_code = BOARD_ID_INIT;
if (cached_ram_code == BOARD_ID_INIT) {
cached_ram_code = (get_adc_index(RAM_ID_HIGH_CHANNEL) << 4 |
get_adc_index(RAM_ID_LOW_CHANNEL));
printk(BIOS_DEBUG, "RAM Code: %#02x\n", cached_ram_code);
}
return cached_ram_code;
}
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