boardid.c

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/* SPDX-License-Identifier: GPL-2.0-only */
 
#include <assert.h>
#include <boardid.h>
#include <console/console.h>
#include <ec/google/chromeec/ec.h>
#include <soc/auxadc.h>
 
/* board_id is provided by ec/google/chromeec/ec_boardid.c */
 
#define ADC_LEVELS 12
 
enum {
        /* RAM IDs */
        RAM_ID_LOW_CHANNEL = 2,
        RAM_ID_HIGH_CHANNEL = 3,
        /* SKU IDs */
        SKU_ID_LOW_CHANNEL = 4,
        SKU_ID_HIGH_CHANNEL = 5,
};
 
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,
};
 
static const unsigned int *adc_voltages[] = {
        [RAM_ID_LOW_CHANNEL] = ram_voltages,
        [RAM_ID_HIGH_CHANNEL] = ram_voltages,
        [SKU_ID_LOW_CHANNEL] = ram_voltages,
        [SKU_ID_HIGH_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)
{
        static uint32_t cached_sku_code = BOARD_ID_INIT;
 
        if (cached_sku_code == BOARD_ID_INIT) {
                cached_sku_code = google_chromeec_get_board_sku();
 
                if (cached_sku_code == CROS_SKU_UNKNOWN) {
                        printk(BIOS_WARNING, "Failed to get SKU code from EC\n");
                        cached_sku_code = (get_adc_index(SKU_ID_HIGH_CHANNEL) << 4 |
                                           get_adc_index(SKU_ID_LOW_CHANNEL));
                }
                printk(BIOS_DEBUG, "SKU Code: %#02x\n", cached_sku_code);
        }
 
        return cached_sku_code;
}
 
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;
}