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sensor: max17055: Add MAX17055 driver

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Add support for the Maxim MAX17055 fueld-gauge sensor.

Signed-off-by: Simon Glass <sjg@chromium.org>
This commit is contained in:
Simon Glass 2020-05-15 16:24:52 -06:00 • committed by Anas Nashif
commit ee34aced6a
9 changed files with 363 additions and 0 deletions
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1
drivers/sensor/CMakeLists.txt
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@ -47,6 +47,7 @@ add_subdirectory_ifdef(CONFIG_LSM6DSL lsm6dsl)
add_subdirectory_ifdef(CONFIG_LSM6DSO lsm6dso)
add_subdirectory_ifdef(CONFIG_LSM9DS0_GYRO lsm9ds0_gyro)
add_subdirectory_ifdef(CONFIG_LSM9DS0_MFD lsm9ds0_mfd)
add_subdirectory_ifdef(CONFIG_MAX17055 max17055)
add_subdirectory_ifdef(CONFIG_MAX30101 max30101)
add_subdirectory_ifdef(CONFIG_MAX44009 max44009)
add_subdirectory_ifdef(CONFIG_MCP9808 mcp9808)

2
drivers/sensor/Kconfig
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@ -123,6 +123,8 @@ source "drivers/sensor/lsm9ds0_gyro/Kconfig"
source "drivers/sensor/lsm9ds0_mfd/Kconfig"
source "drivers/sensor/max17055/Kconfig"
source "drivers/sensor/max30101/Kconfig"
source "drivers/sensor/max44009/Kconfig"

7
drivers/sensor/max17055/CMakeLists.txt Normal file
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@ -0,0 +1,7 @@
# Copyright 2020 Google LLC
#
# SPDX-License-Identifier: Apache-2.0
zephyr_library()
zephyr_library_sources_ifdef(CONFIG_MAX17055 max17055.c)

12
drivers/sensor/max17055/Kconfig Normal file
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@ -0,0 +1,12 @@
# Copyright 2020 Google LLC
#
# SPDX-License-Identifier: Apache-2.0
config MAX17055
bool "MAX17055 Fuel Gauge"
depends on I2C && HAS_DTS_I2C
help
Enable I2C-based driver for MAX17055 Fuel Gauge. This driver supports
reading various sensor settings including charge level percentage,
time to full/empty, design voltage, temperature and remaining
capacity in mA.

237
drivers/sensor/max17055/max17055.c Normal file
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@ -0,0 +1,237 @@
/*
* Copyright 2020 Google LLC
*
* SPDX-License-Identifier: Apache-2.0
*/
#include <drivers/i2c.h>
#include <drivers/sensor.h>
#include <logging/log.h>
LOG_MODULE_REGISTER(max17055, CONFIG_SENSOR_LOG_LEVEL);
#include "max17055.h"
#define DT_DRV_COMPAT maxim_max17055
/**
* @brief Read a register value
*
* Registers have an address and a 16-bit value
*
* @param priv Private data for the driver
* @param reg_addr Register address to read
* @param val Place to put the value on success
* @return 0 if successful, or negative error code from I2C API
*/
static int max17055_reg_read(struct max17055_data *priv, int reg_addr,
int16_t *valp)
{
uint8_t i2c_data[2];
int rc;
rc = i2c_burst_read(priv->i2c, DT_INST_REG_ADDR(0), reg_addr,
i2c_data, 2);
if (rc < 0) {
LOG_ERR("Unable to read register");
return rc;
}
*valp = (i2c_data[1] << 8) | i2c_data[0];
return 0;
}
/**
* @brief Convert capacity in MAX17055 units to milliamps
*
* @param rsense_mohms Value of Rsense in milliohms
* @param val Value to convert (taken from a MAX17055 register)
* @return corresponding value in milliamps
*/
static int capacity_to_ma(unsigned int rsense_mohms, int16_t val)
{
int lsb_units, rem;
/* Get units for the LSB in uA */
lsb_units = 5 * 1000 / rsense_mohms;
/* Get remaining capacity in uA */
rem = val * lsb_units;
return rem;
}
static void set_millis(struct sensor_value *val, int val_millis)
{
val->val1 = val_millis / 1000;
val->val2 = (val_millis % 1000) * 1000;
}
/**
* @brief sensor value get
*
* @param dev MAX17055 device to access
* @param chan Channel number to read
* @param valp Returns the sensor value read on success
* @return 0 if successful
* @return -ENOTSUP for unsupported channels
*/
static int max17055_channel_get(struct device *dev, enum sensor_channel chan,
struct sensor_value *valp)
{
const struct max17055_config *const config = dev->config_info;
struct max17055_data *const priv = dev->driver_data;
unsigned int tmp;
switch (chan) {
case SENSOR_CHAN_GAUGE_VOLTAGE:
/* Get voltage in uV */
tmp = priv->voltage * 1250 / 16;
valp->val1 = tmp / 1000000;
valp->val2 = tmp % 1000000;
break;
case SENSOR_CHAN_GAUGE_AVG_CURRENT: {
int cap_ma;
cap_ma = capacity_to_ma(config->rsense_mohms,
priv->avg_current);
set_millis(valp, cap_ma);
break;
}
case SENSOR_CHAN_GAUGE_STATE_OF_CHARGE:
valp->val1 = priv->state_of_charge / 256;
valp->val2 = priv->state_of_charge % 256 * 1000000 / 256;
break;
case SENSOR_CHAN_GAUGE_TEMP:
valp->val1 = priv->internal_temp / 256;
valp->val2 = priv->internal_temp % 256 * 1000000 / 256;
break;
case SENSOR_CHAN_GAUGE_FULL_CHARGE_CAPACITY:
tmp = capacity_to_ma(config->rsense_mohms, priv->full_cap);
set_millis(valp, tmp);
break;
case SENSOR_CHAN_GAUGE_REMAINING_CHARGE_CAPACITY:
tmp = capacity_to_ma(config->rsense_mohms, priv->remaining_cap);
set_millis(valp, tmp);
break;
case SENSOR_CHAN_GAUGE_TIME_TO_EMPTY:
/* Get time in ms */
if (priv->time_to_empty == 0xffff) {
valp->val1 = 0;
valp->val2 = 0;
} else {
tmp = priv->time_to_empty * 5625;
set_millis(valp, tmp);
}
break;
case SENSOR_CHAN_GAUGE_TIME_TO_FULL:
if (priv->time_to_full == 0xffff) {
valp->val1 = 0;
valp->val2 = 0;
} else {
/* Get time in ms */
tmp = priv->time_to_full * 5625;
set_millis(valp, tmp);
}
break;
case SENSOR_CHAN_GAUGE_CYCLE_COUNT:
valp->val1 = priv->cycle_count / 100;
valp->val2 = priv->cycle_count % 100 * 10000;
break;
case SENSOR_CHAN_GAUGE_NOM_AVAIL_CAPACITY:
tmp = capacity_to_ma(config->rsense_mohms, priv->design_cap);
set_millis(valp, tmp);
break;
case SENSOR_CHAN_GAUGE_DESIGN_VOLTAGE:
set_millis(valp, config->design_voltage);
break;
case SENSOR_CHAN_GAUGE_DESIRED_VOLTAGE:
set_millis(valp, config->desired_voltage);
break;
case SENSOR_CHAN_GAUGE_DESIRED_CHARGING_CURRENT:
valp->val1 = config->desired_charging_current;
valp->val2 = 0;
break;
default:
return -ENOTSUP;
}
return 0;
}
static int max17055_sample_fetch(struct device *dev, enum sensor_channel chan)
{
struct max17055_data *priv = dev->driver_data;
struct {
int reg_addr;
int16_t *dest;
} regs[] = {
{ VCELL, &priv->voltage },
{ AVG_CURRENT, &priv->avg_current },
{ REP_SOC, &priv->state_of_charge },
{ INT_TEMP, &priv->internal_temp },
{ REP_CAP, &priv->remaining_cap },
{ FULL_CAP_REP, &priv->full_cap },
{ TTE, &priv->time_to_empty },
{ TTF, &priv->time_to_full },
{ CYCLES, &priv->cycle_count },
{ DESIGN_CAP, &priv->design_cap },
};
__ASSERT_NO_MSG(chan == SENSOR_CHAN_ALL);
for (size_t i = 0; i < ARRAY_SIZE(regs); i++) {
int rc;
rc = max17055_reg_read(priv, regs[i].reg_addr, regs[i].dest);
if (rc != 0) {
LOG_ERR("Failed to read channel %d", chan);
return rc;
}
}
return 0;
}
/**
* @brief initialise the fuel gauge
*
* @return 0 for success
* @return -EINVAL if the I2C controller could not be found
*/
static int max17055_gauge_init(struct device *dev)
{
struct max17055_data *priv = dev->driver_data;
const struct max17055_config *const config = dev->config_info;
priv->i2c = device_get_binding(config->bus_name);
if (!priv->i2c) {
LOG_ERR("Could not get pointer to %s device", config->bus_name);
return -EINVAL;
}
return 0;
}
static const struct sensor_driver_api max17055_battery_driver_api = {
.sample_fetch = max17055_sample_fetch,
.channel_get = max17055_channel_get,
};
#define MAX17055_INIT(index) \
static struct max17055_data max17055_driver_##index; \
\
static const struct max17055_config max17055_config_##index = { \
.bus_name = DT_INST_BUS_LABEL(index), \
.rsense_mohms = DT_INST_PROP(index, rsense_mohms), \
.design_voltage = DT_INST_PROP(index, design_voltage), \
.desired_voltage = DT_INST_PROP(index, desired_voltage), \
.desired_charging_current = \
DT_INST_PROP(index, desired_charging_current), \
}; \
\
DEVICE_AND_API_INIT(max17055_##index, DT_INST_LABEL(index), \
&max17055_gauge_init, &max17055_driver_##index, \
&max17055_config_##index, POST_KERNEL, \
CONFIG_SENSOR_INIT_PRIORITY, \
&max17055_battery_driver_api)
DT_INST_FOREACH_STATUS_OKAY(MAX17055_INIT);

60
drivers/sensor/max17055/max17055.h Normal file
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@ -0,0 +1,60 @@
/*
* Copyright 2020 Google LLC
*
* SPDX-License-Identifier: Apache-2.0
*/
#ifndef ZEPHYR_DRIVERS_SENSOR_BATTERY_MAX17055_H_
#define ZEPHYR_DRIVERS_SENSOR_BATTERY_MAX17055_H_
/* Register addresses */
enum {
REP_CAP = 0x5,
REP_SOC = 0x6,
INT_TEMP = 0x8,
VCELL = 0x9,
AVG_CURRENT = 0xb,
FULL_CAP_REP = 0x10,
TTE = 0x11,
CYCLES = 0x17,
DESIGN_CAP = 0x18,
TTF = 0x20,
};
struct max17055_data {
struct device *i2c;
/* Current cell voltage in units of 1.25/16mV */
uint16_t voltage;
/* Average current in units of 1.5625uV / Rsense */
int16_t avg_current;
/* Remaining capacity as a %age */
uint16_t state_of_charge;
/* Internal temperature in units of 1/256 degrees C */
int16_t internal_temp;
/* Full charge capacity in 5/Rsense uA */
uint16_t full_cap;
/* Remaining capacity in 5/Rsense uA */
uint16_t remaining_cap;
/* Time to empty in seconds */
uint16_t time_to_empty;
/* Time to full in seconds */
uint16_t time_to_full;
/* Cycle count in 1/100ths (number of charge/discharge cycles) */
uint16_t cycle_count;
/* Design capacity in 5/Rsense uA */
uint16_t design_cap;
};
struct max17055_config {
char *bus_name;
/* Value of Rsense resistor in milliohms (typicallly 5 or 10) */
uint16_t rsense_mohms;
/* Design voltage of cell in mV */
uint16_t design_voltage;
/* Desired voltage of cell in mV */
uint16_t desired_voltage;
/* Desired charging current in mA */
uint16_t desired_charging_current;
};
#endif

33
dts/bindings/sensor/maxim,max17055.yaml Normal file
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@ -0,0 +1,33 @@
#
# Copyright 2020 Google LLC
#
# SPDX-License-Identifier: Apache-2.0
#
description: Maxim MAX17055 Fuel Gauge
compatible: "maxim,max17055"
include: i2c-device.yaml
properties:
design-voltage:
type: int
required: true
description: Battery Design Voltage in mV (3300 to 4400)
desired-voltage:
type: int
required: true
description: Battery Desired Voltage in mV (3300 to 4400)
desired-charging-current:
type: int
required: true
description: Battery Design Charging Current in mA (e.g. 2000)
rsense-mohms:
type: int
required: true
description: >
Value of Rsense resistor in milliohms (e.g. 5). It cannot be 0.

10
tests/drivers/build_all/i2c.dtsi
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@ -543,3 +543,13 @@ test_i2c_itds: itds@18 {
reg = <0x18>;
int-gpios = <&test_gpio 0 0>;
};
test_i2c_max17055: max17055@49 {
compatible = "maxim,max17055";
label = "max17055";
reg = <0x49>;
design-voltage = <3860>;
desired-voltage = <4400>;
desired-charging-current = <2000>;
rsense-mohms = <5>;
};

1
tests/drivers/build_all/sensors_i_z.conf
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@ -23,6 +23,7 @@ CONFIG_LSM9DS0_GYRO=y
CONFIG_LSM9DS0_MFD=y
CONFIG_MAX30101=y
CONFIG_MAX44009=y
CONFIG_MAX17055=y
CONFIG_MCP9808=y
CONFIG_MPU6050=y
CONFIG_MS5607=y