incubator-nuttx/drivers/power/battery/bq27426.c

437 lines
13 KiB
C

/****************************************************************************
* drivers/power/battery/bq27426.c
*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership. The
* ASF licenses this file to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance with the
* License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations
* under the License.
*
****************************************************************************/
/* Lower half driver for BQ27426 battery fuel gauge */
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#include <sys/types.h>
#include <unistd.h>
#include <stdint.h>
#include <stdio.h>
#include <stdbool.h>
#include <errno.h>
#include <debug.h>
#include <nuttx/kmalloc.h>
#include <nuttx/signal.h>
#include <nuttx/i2c/i2c_master.h>
#include <nuttx/power/battery_gauge.h>
#include <nuttx/power/bq27426.h>
/* This driver requires:
*
* CONFIG_BATTERY - Upper half battery driver support
* CONFIG_I2C - I2C support
* CONFIG_BQ27426 - And the driver must be explicitly selected.
*/
#if defined(CONFIG_BATTERY_GAUGE) && defined(CONFIG_I2C) && \
defined(CONFIG_BQ27426)
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
/****************************************************************************
* Private
****************************************************************************/
/* Parameters for the capacity() function,
* to specify which capacity to read in mAh
*/
typedef enum
{
REMAIN, /* Remaining Capacity (DEFAULT) */
FULL, /* Full Capacity */
AVAIL, /* Available Capacity */
AVAIL_FULL, /* Full Available Capacity */
REMAIN_F, /* Remaining Capacity Filtered */
REMAIN_UF, /* Remaining Capacity Unfiltered */
FULL_F, /* Full Capacity Filtered */
FULL_UF /* Full Capacity Unfiltered */
} capacity_measure;
/****************************************************************************
* Private
****************************************************************************/
struct bq27426_dev_s
{
/* The common part of the battery driver visible to the upper-half driver */
struct battery_gauge_dev_s dev; /* Battery gauge device */
/* Data fields specific to the lower half bq27426 driver follow */
FAR struct i2c_master_s *i2c; /* I2C interface */
uint8_t addr; /* I2C address */
uint32_t frequency; /* I2C frequency */
};
/****************************************************************************
* Private Function Prototypes
****************************************************************************/
/* I2C support */
static int bq27426_getreg16(FAR struct bq27426_dev_s *priv, uint8_t regaddr,
FAR uint16_t *regval);
static int bq27426_putreg16(FAR struct bq27426_dev_s *priv, uint8_t regaddr,
uint16_t regval);
static inline int bq27426_getvoltage(FAR struct bq27426_dev_s *priv,
b16_t *voltage);
static inline int bq27426_getsoc(FAR struct bq27426_dev_s *priv,
b16_t *soc);
static inline int bq27426_getcapacity(FAR struct bq27426_dev_s *priv,
uint8_t capacity,
b16_t *value);
static inline int bq27426_get_device_id(FAR struct bq27426_dev_s *priv,
uint16_t *id);
/* Battery driver lower half methods */
static int bq27426_state(struct battery_gauge_dev_s *dev, int *status);
static int bq27426_online(struct battery_gauge_dev_s *dev, bool *status);
static int bq27426_voltage(struct battery_gauge_dev_s *dev, b16_t *value);
static int bq27426_capacity_full(struct battery_gauge_dev_s *dev,
b16_t *capacity_full);
/****************************************************************************
* Private Data
****************************************************************************/
static const struct battery_gauge_operations_s g_bq27426ops =
{
bq27426_state,
bq27426_online,
bq27426_voltage,
bq27426_capacity_full,
};
/****************************************************************************
* Private Functions
****************************************************************************/
/****************************************************************************
* Name: bq27426_getreg16
*
* Description:
* Read a 16-bit value from a bq27426 register pair.
*
* START <I2C write address> ACK <Reg address> ACK
* REPEATED-START <I2C read address> ACK Data0 ACK Data1 NO-ACK STOP
*
****************************************************************************/
static int bq27426_getreg16(FAR struct bq27426_dev_s *priv, uint8_t regaddr,
FAR uint16_t *regval)
{
struct i2c_config_s config;
uint8_t buffer[2];
int ret;
/* Set up the configuration and perform the write-read operation */
config.frequency = priv->frequency;
config.address = priv->addr;
config.addrlen = 7;
/* Write the register address */
ret = i2c_write(priv->i2c, &config, &regaddr, 1);
if (ret < 0)
{
baterr("i2c_write failed: %d\n", ret);
return ret;
}
/* Restart and read 16-bits from the register */
ret = i2c_read(priv->i2c, &config, buffer, 2);
if (ret < 0)
{
baterr("i2c_read failed: %d\n", ret);
return ret;
}
*regval = ((uint16_t) buffer[1] << 8) | buffer[0];
return OK;
}
/****************************************************************************
* Name: bq27426_putreg16
*
* Description:
* Write a 16-bit value to a bq27426 register pair.
*
* START <I2C write address> ACK <Reg address> ACK Data0 ACK Data1 ACK STOP
*
****************************************************************************/
static int bq27426_putreg16(FAR struct bq27426_dev_s *priv, uint8_t regaddr,
uint16_t regval)
{
struct i2c_config_s config;
uint8_t buffer[3];
baterr("addr: %02x regval: %04x\n", regaddr, regval);
/* Set up a 3 byte message to send */
buffer[0] = regaddr;
buffer[1] = (uint8_t)(regval & 0x00ff);
buffer[2] = (uint8_t)(regval >> 8);
/* Set up the configuration and perform the write-read operation */
config.frequency = priv->frequency;
config.address = priv->addr;
config.addrlen = 7;
/* Write the register address followed by the data (no RESTART) */
return i2c_write(priv->i2c, &config, buffer, 3);
}
/****************************************************************************
* Name: bq27426_get_device_id
*
* Description:
* Read the ID register
*
****************************************************************************/
static inline int bq27426_get_device_id(FAR struct bq27426_dev_s *priv,
uint16_t *id)
{
uint16_t regval = 0;
int ret;
ret = bq27426_putreg16(priv, BQ27426_COMMAND_CONTROL,
BQ27426_CONTROL_DEVICE_TYPE);
if (ret == OK)
{
ret = bq27426_getreg16(priv, BQ27426_COMMAND_CONTROL, &regval);
*id = regval;
}
return ret;
}
/****************************************************************************
* Name: bq27426_getvoltage
*
* Description:
* Read the VCELL register and scale the returned value
*
****************************************************************************/
static inline int bq27426_getvoltage(FAR struct bq27426_dev_s *priv,
b16_t *voltage)
{
uint16_t regval = 0;
int ret;
ret = bq27426_getreg16(priv, BQ27426_COMMAND_VOLTAGE, &regval);
if (ret == OK)
{
*voltage = regval;
}
return ret;
}
/****************************************************************************
* Name: bq27426_getsoc
*
* Description:
* Read the SOC register and scale the returned value
*
****************************************************************************/
static inline int bq27426_getsoc(FAR struct bq27426_dev_s *priv, b16_t *soc)
{
uint16_t regval = 0;
int ret;
ret = bq27426_getreg16(priv, BQ27426_COMMAND_SOC, &regval);
if (ret == OK)
*soc = regval;
return ret;
}
/****************************************************************************
* Name: bq27426_getcapacity
*
* Description:
* Read the SOC register and scale the returned value
*
****************************************************************************/
static inline int bq27426_getcapacity(FAR struct bq27426_dev_s *priv,
uint8_t capacity, b16_t *value)
{
uint16_t regval = 0;
return bq27426_getreg16(priv, capacity, &regval);
}
/****************************************************************************
* Name: bq27426_state
*
* Description:
* Return the battery state
*
****************************************************************************/
static int bq27426_state(struct battery_gauge_dev_s *dev, int *status)
{
FAR struct bq27426_dev_s *priv = (FAR struct bq27426_dev_s *)dev;
b16_t soc = 0;
int ret;
/* Only a few of the possible battery states are supported by this driver:
*
* BATTERY_UNKNOWN - Returned on error conditions
* BATTERY_IDLE - This is what will usually be reported
* BATTERY_FULL - This will be reported if the SoC is greater than 95%
* BATTERY_CHARGING and BATTERY_DISCHARGING - I don't think this hardware
* knows anything about current (charging or dischargin).
*
*/
ret = bq27426_getsoc(priv, &soc);
if (ret < 0)
{
*status = BATTERY_UNKNOWN;
return ret;
}
*status = soc;
return OK;
}
/****************************************************************************
* Name: bq27426_voltage
*
* Description:
* Current battery voltage
*
****************************************************************************/
static int bq27426_voltage(struct battery_gauge_dev_s *dev, b16_t *value)
{
FAR struct bq27426_dev_s *priv = (FAR struct bq27426_dev_s *)dev;
return bq27426_getvoltage(priv, value);
}
/****************************************************************************
* Name: bq27426_capacity_full
*
* Description:
* Battery capacity (mAh)
*
****************************************************************************/
static int bq27426_capacity_full(struct battery_gauge_dev_s *dev,
b16_t *value)
{
FAR struct bq27426_dev_s *priv = (FAR struct bq27426_dev_s *)dev;
return bq27426_getcapacity(priv, BQ27426_COMMAND_FULL_CAP_FIL, value);
}
/****************************************************************************
* Name: bq27426_online
*
* Description:
* Return true if the batter is online
*
****************************************************************************/
static int bq27426_online(struct battery_gauge_dev_s *dev, bool *status)
{
/* There is no concept of online/offline in this driver */
*status = true;
return OK;
}
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: bq27426_initialize
*
* Description:
* Initialize the bq27426 battery driver and return an instance of the
* lower_half interface that may be used with battery_register();
*
* This driver requires:
*
* CONFIG_BATTERY - Upper half battery driver support
* CONFIG_I2C - I2C support
* CONFIG_BQ27426 - And the driver must be explicitly selected.
*
* Input Parameters:
* i2c - An instance of the I2C interface to use to communicate with the bq
* addr - The I2C address of the bq27426 (Better be 0x55).
* frequency - The I2C frequency
*
* Returned Value:
* A pointer to the initializeed lower-half driver instance. A NULL
* pointer is returned on a failure to initialize the bq27426 lower half.
*
****************************************************************************/
FAR struct battery_gauge_dev_s *bq27426_initialize(
FAR struct i2c_master_s *i2c,
uint8_t addr,
uint32_t frequency)
{
FAR struct bq27426_dev_s *priv;
/* Initialize the bq27426 device structure */
priv = kmm_zalloc(sizeof(struct bq27426_dev_s));
if (priv)
{
/* Initialize the bq27426 device structure */
priv->dev.ops = &g_bq27426ops;
priv->i2c = i2c;
priv->addr = addr;
priv->frequency = frequency;
}
return (FAR struct battery_gauge_dev_s *)priv;
}
#endif /* CONFIG_BATTERY && CONFIG_I2C && CONFIG_BQ27426 */