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| author | Jonathan Brandmeyer <jbrandmeyer@chromium.org> | 2018-08-03 13:24:06 -0600 |
|---|---|---|
| committer | chrome-bot <chrome-bot@chromium.org> | 2018-08-08 04:29:20 -0700 |
| commit | b80693e94e6e9aa0a382c39c20efba6f2c7403a9 (patch) | |
| tree | b44a8b48858906c6f8a3875b6a69d7c2b6908ddc /driver/battery | |
| parent | 5d2cdcab232748095d1efeb4e5c0fc23b13adb67 (diff) | |
| download | chrome-ec-b80693e94e6e9aa0a382c39c20efba6f2c7403a9.tar.gz | |
battery: Optionally prevent boot at low SOC with cell imbalance.
Measure the cell imbalance with method dispatch to a per-battery
method, such that families with a plurality of configurable batteries
can support them all. By default, cell imbalance is taken to be 'zero'
in case we don't support that battery's management IC. Provide a driver
for reading cell voltages for the TI BQ4050 family. This IC is quite
popular, but by no means universal.
BUG=b:111214767
BRANCH=none
TEST=Boot on Careena with a custom debug print statement, showing that
we can measure the typical battery voltages during and after the boot at
the battery status polling interval.
Change-Id: I235389b252ac9c373aa9706dbd1066f7c0bbce71
Signed-off-by: Jonathan Brandmeyer <jbrandmeyer@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/1162663
Reviewed-by: Daisuke Nojiri <dnojiri@chromium.org>
Diffstat (limited to 'driver/battery')
| -rw-r--r-- | driver/battery/bq4050.c | 39 | ||||
| -rw-r--r-- | driver/battery/smart.c | 5 |
2 files changed, 44 insertions, 0 deletions
diff --git a/driver/battery/bq4050.c b/driver/battery/bq4050.c new file mode 100644 index 0000000000..6f2890ff2d --- /dev/null +++ b/driver/battery/bq4050.c @@ -0,0 +1,39 @@ +/* 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) + * and BQ40Z552. + */ + +#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; +} + diff --git a/driver/battery/smart.c b/driver/battery/smart.c index 743ebc1ee1..0ae35a5fba 100644 --- a/driver/battery/smart.c +++ b/driver/battery/smart.c @@ -351,6 +351,11 @@ void battery_get_params(struct batt_params *batt) if ((batt_new.flags & BATT_FLAG_BAD_ANY) != BATT_FLAG_BAD_ANY) batt_new.flags |= BATT_FLAG_RESPONSIVE; +#ifdef CONFIG_BATTERY_MEASURE_IMBALANCE + if (battery_imbalance_mv() > CONFIG_BATTERY_MAX_IMBALANCE_MV) + batt_new.flags |= BATT_FLAG_IMBALANCED_CELL; +#endif + #if defined(CONFIG_BATTERY_PRESENT_CUSTOM) || \ defined(CONFIG_BATTERY_PRESENT_GPIO) /* Hardware can tell us for certain */ |