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/* Copyright 2018 The Chromium OS Authors. All rights reserved.
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*
* Smart battery driver for TI BQ4050 family, including BQ40Z50 (and -R1, -R2),
* BQ40Z552, and BQ40Z60.
*/
#include "battery_smart.h"
#include "util.h"
#include <stdint.h>
int battery_bq4050_imbalance_mv(void)
{
/*
* The BQ4050 family can manage up to four cells. In testing it always
* returns a voltage for each cell, regardless of the number of cells
* actually installed in the pack. Unpopulated cells read exactly zero.
*/
static const uint8_t cell_voltage_address[4] = {
0x3c, 0x3d, 0x3e, 0x3f
};
int i, res, cell_voltage;
int n_cells = 0;
int max_voltage = 0;
int min_voltage = 0xffff;
for (i = 0; i != ARRAY_SIZE(cell_voltage_address); ++i) {
res = sb_read(cell_voltage_address[i], &cell_voltage);
if (res == EC_SUCCESS && cell_voltage != 0) {
n_cells++;
max_voltage = MAX(max_voltage, cell_voltage);
min_voltage = MIN(min_voltage, cell_voltage);
}
}
return (n_cells == 0) ? 0 : max_voltage - min_voltage;
}
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