/****************************************************************************
* drivers/power/max1704x.c
* Lower half driver for MAX1704x battery charger
*
* Copyright (C) 2012 Gregory Nutt. All rights reserved.
* Author: Gregory Nutt <gnutt@nuttx.org>
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
* 3. Neither the name NuttX nor the names of its contributors may be
* used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*
****************************************************************************/
/* "The MAX17040/MAX17041 are ultra-compact, low-cost, host-side fuel-gauge
* systems for lithium-ion (Li+) batteries in handheld and portable equipment.
* The MAX17040 is configured to operate with a single lithium cell and the
* MAX17041 is configured for a dual-cell 2S pack.
*/
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#include <sys/types.h>
#include <stdint.h>
#include <stdbool.h>
#include <errno.h>
#include <debug.h>
#include <nuttx/kmalloc.h>
#include <nuttx/i2c.h>
#include <nuttx/power/battery.h>
/* This driver requires:
*
* CONFIG_BATTERY - Upper half battery driver support
* CONFIG_I2C - I2C support
* CONFIG_I2C_MAX1704X - And the driver must be explictly selected.
*/
#if defined(CONFIG_BATTERY) && defined(CONFIG_I2C) && defined(CONFIG_I2C_MAX1704X)
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
/* Configuration ************************************************************/
/* CONFIG_I2C_MAX17040 or CONFIG_I2C_MAX17041 - The driver must know which
* chip is on the board in order to scale the voltage correctly.
*/
#if !defined(CONFIG_I2C_MAX17040) && !defined(CONFIG_I2C_MAX17041)
# warning "Assuming CONFIG_I2C_MAX17040"
# define CONFIG_I2C_MAX17040 1
#endif
/* MAX1704x Register Definitions ********************************************/
/* "All host interaction with the MAX17040/MAX17041 is handled by writing to
* and reading from register locations. The MAX17040/MAX17041 have six 16-bit
* registers: SOC, VCELL, MODE, VERSION, RCOMP, and COMMAND. Register reads
* and writes are only valid if all 16 bits are transferred..."
*/
/* "VCELL Register. Battery voltage is measured at the CELL pin input with
* respect to GND over a 0 to 5.00V range for the MAX17040 and 0 to 10.00V
* for the MAX17041 with resolutions of 1.25mV and 2.50mV, respectively..."
*/
#define MAX1407X_VCELL_ADDR 0x02 /* Bits 4-15: Bits 0-11 of the battery voltage */
/* VCELL conversion macros */
#define MAX14700_VCELL_CONV 82 /* 0.00125 v * 65536 */
#define MAX14070_VCELL(v) ((b16_t)(v) * MAX14700_VCELL_CONV)
#define MAX14701_VCELL_CONV 163 /* 0.0025 v * 65536 */
#define MAX14071_VCELL(v) ((b16_t)(v) * MAX14701_VCELL_CONV)
#ifdef CONFIG_I2C_MAX17040
# define MAX1407X_VCELL(v) MAX14070_VCELL(v)
#else
# define MAX1407X_VCELL(v) MAX14071_VCELL(v)
#endif
/* "SOC Register. The SOC register is a read-only register that displays the
* state of charge of the cell as calculated by the ModelGauge algorithm. The
* result is displayed as a percentage of the cell�s full capacity...
*
* "...Units of % can be directly determined by observing only the high byte
* of the SOC register. The low byte provides additional resolution in units
* 1/256%.
*/
#define MAX1407X_SOC_ADDR 0x04 /* Bits 0-15: Full SOC */
/* SoC conversion macros */
#define MAX1407X_SOC(s) ((b16_t)(s) << 8)
#define MAX17040_SOC_FULL itob16(95) /* We say full if Soc >= 95% */
/* "MODE Register.The MODE register allows the host processor to send special
* commands to the IC."
*/
#define MAX1407X_MODE_ADDR 0x06 /* Bits 0-15: 16-bit MODE */
/* Supported modes */
#define MAX1407X_MODE_QUICKSTART 0x4000
/* "The VERSION register is a read-only register that contains a value
* indicating the production version of the MAX17040/MAX17041."
*/
#define MAX1407X_VERSION_ADDR 0x08 /* Bits 0-15: 16-bit VERSION */
/* "RCOMP Register. RCOMP is a 16-bit value used to compensate the ModelGauge
* algorithm. RCOMP can be adjusted to optimize performance for different
* lithium chemistries or different operating temperatures... The factory-
* default value for RCOMP is 9700h."
*/
#define MAX1407X_RCOMP_ADDR 0x0c /* Bits 0-15: 16-bit RCOMP */
/* "COMMAND Register. The COMMAND register allows the host processor to send
* special commands to the IC..."
*/
#define MAX1407X_COMMAND_ADDR 0xfe /* Bits 0-7: 16-bit COMMAND */
/* Supported copmmands */
#define MAX1407X_COMMAND_POR 0x5400
/* Debug ********************************************************************/
#ifdef CONFIG_DEBUG_MAX1704X
# define batdbg dbg
#else
# ifdef CONFIG_CPP_HAVE_VARARGS
# define batdbg(x...)
# else
# define batdbg (void)
# endif
#endif
/****************************************************************************
* Private
****************************************************************************/
struct max1704x_dev_s
{
/* The common part of the battery driver visible to the upper-half driver */
FAR const struct battery_operations_s *ops; /* Battery operations */
sem_t batsem; /* Enforce mutually exclusive access */
/* Data fields specific to the lower half MAX1704x driver follow */
FAR struct i2c_dev_s *i2c; /* I2C interface */
uint8_t addr; /* I2C address */
uint32_t frequency; /* I2C frequency */
};
/****************************************************************************
* Private Function Prototypes
****************************************************************************/
/* I2C support */
static int max1704x_getreg16(FAR struct max1704x_dev_s *priv, uint8_t regaddr,
FAR uint16_t *regval);
static int max1704x_putreg16(FAR struct max1704x_dev_s *priv, uint8_t regaddr,
uint16_t regval);
static inline int max1704x_getvcell(FAR struct max1704x_dev_s *priv,
b16_t *vcell);
static inline int max1704x_getsoc(FAR struct max1704x_dev_s *priv,
b16_t *soc);
static inline int max1704x_setquikstart(FAR struct max1704x_dev_s *priv);
static inline int max1704x_getversion(FAR struct max1704x_dev_s *priv,
uint16_t *version);
static inline int max1704x_reset(FAR struct max1704x_dev_s *priv);
/* Battery driver lower half methods */
static int max1704x_state(struct battery_dev_s *dev, int *status);
static int max1704x_online(struct battery_dev_s *dev, bool *status);
static int max1704x_voltage(struct battery_dev_s *dev, b16_t *value);
static int max1704x_capacity(struct battery_dev_s *dev, b16_t *value);
/****************************************************************************
* Private Data
****************************************************************************/
static const struct battery_operations_s g_max1704xops =
{
max1704x_state,
max1704x_online,
max1704x_voltage,
max1704x_capacity
};
/****************************************************************************
* Private Functions
****************************************************************************/
/****************************************************************************
* Name: max1704x_getreg16
*
* Description:
* Read a 16-bit value from a MAX1704x register pair.
*
* START <I2C write address> ACK <Reg address> ACK
* REPEATED-START <I2C read address> ACK Data0 ACK Data1 NO-ACK STOP
*
****************************************************************************/
static int max1704x_getreg16(FAR struct max1704x_dev_s *priv, uint8_t regaddr,
FAR uint16_t *regval)
{
uint8_t buffer[2];
int ret;
/* Set the I2C address and address size */
I2C_SETADDRESS(priv->i2c, priv->addr, 7);
/* Write the register address */
ret = I2C_WRITE(priv->i2c, ®addr, 1);
if (ret < 0)
{
batdbg("I2C_WRITE failed: %d\n", ret);
return ret;
}
/* Restart and read 16-bits from the register */
ret = I2C_READ(priv->i2c, buffer, 2);
if (ret < 0)
{
batdbg("I2C_READ failed: %d\n", ret);
return ret;
}
/* Return the 16-bit value */
return (uint16_t)buffer[0] << 8 | (uint16_t)buffer[1];
return OK;
}
/****************************************************************************
* Name: max1704x_putreg16
*
* Description:
* Write a 16-bit value to a MAX1704x register pair.
*
* START <I2C write address> ACK <Reg address> ACK Data0 ACK Data1 ACK STOP
*
****************************************************************************/
static int max1704x_putreg16(FAR struct max1704x_dev_s *priv, uint8_t regaddr,
uint16_t regval)
{
uint8_t buffer[3];
batdbg("addr: %02x regval: %08x\n", regaddr, regval);
/* Set up a 3 byte message to send */
buffer[0] = regaddr;
buffer[1] = (uint8_t)(regval >> 8);
buffer[2] = (uint8_t)(regval & 0xff);
/* Set the I2C address and address size */
I2C_SETADDRESS(priv->i2c, priv->addr, 7);
/* Write the register address followed by the data (no RESTART) */
return I2C_WRITE(priv->i2c, buffer, 3);
}
/****************************************************************************
* Name: max1704x_getvcell
*
* Description:
* Read the VCELL register and scale the returned value
*
****************************************************************************/
static inline int max1704x_getvcell(FAR struct max1704x_dev_s *priv,
b16_t *vcell)
{
uint16_t regval = 0;
int ret;
ret = max1704x_getreg16(priv, MAX1407X_VCELL_ADDR, ®val);
if (ret == OK)
{
*vcell = MAX1407X_VCELL(regval);
}
return ret;
}
/****************************************************************************
* Name: max1704x_getsoc
*
* Description:
* Read the SOC register and scale the returned value
*
****************************************************************************/
static inline int max1704x_getsoc(FAR struct max1704x_dev_s *priv,
b16_t *soc)
{
uint16_t regval = 0;
int ret;
ret = max1704x_getreg16(priv, MAX1407X_VCELL_ADDR, ®val);
if (ret == OK)
{
*soc = MAX1407X_SOC(regval);
}
return ret;
}
/****************************************************************************
* Name: max1704x_setquikstart
*
* Description:
* Set Quickstart mode
*
****************************************************************************/
static inline int max1704x_setquikstart(FAR struct max1704x_dev_s *priv)
{
return max1704x_putreg16(priv, MAX1407X_MODE_ADDR, MAX1407X_MODE_QUICKSTART);
}
/****************************************************************************
* Name: max1704x_getversion
*
* Description:
* Read the SOC register and scale the returned value
*
****************************************************************************/
static inline int max1704x_getversion(FAR struct max1704x_dev_s *priv,
uint16_t *version)
{
return max1704x_getreg16(priv, MAX1407X_VCELL_ADDR, version);
}
/****************************************************************************
* Name: max1704x_setrcomp
*
* Description:
* Set Quickstart mode
*
****************************************************************************/
static inline int max1704x_setrcomp(FAR struct max1704x_dev_s *priv, uint16_t rcomp)
{
return max1704x_putreg16(priv, MAX1407X_RCOMP_ADDR, rcomp);
}
/****************************************************************************
* Name: max1704x_reset
*
* Description:
* Reset the MAX1704x
*
****************************************************************************/
static inline int max1704x_reset(FAR struct max1704x_dev_s *priv)
{
return max1704x_putreg16(priv, MAX1407X_COMMAND_ADDR, MAX1407X_COMMAND_POR);
}
/****************************************************************************
* Name: max1704x_state
*
* Description:
* Return the current battery state
*
****************************************************************************/
static int max1704x_state(struct battery_dev_s *dev, int *status)
{
FAR struct max1704x_dev_s *priv = (FAR struct max1704x_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 = max1704x_getsoc(priv, &soc);
if (ret < 0)
{
*status = BATTERY_UNKNOWN;
return ret;
}
/* Is the battery fully charged? */
if (soc > MAX17040_SOC_FULL)
{
*status = BATTERY_FULL;
}
else
{
*status = BATTERY_IDLE;
}
return OK;
}
/****************************************************************************
* Name: max1704x_online
*
* Description:
* Return true if the batter is online
*
****************************************************************************/
static int max1704x_online(struct battery_dev_s *dev, bool *status)
{
/* There is no concept of online/offline in this driver */
*status = true;
return OK;
}
/****************************************************************************
* Name: max1704x_voltage
*
* Description:
* Current battery voltage
*
****************************************************************************/
static int max1704x_voltage(struct battery_dev_s *dev, b16_t *value)
{
FAR struct max1704x_dev_s *priv = (FAR struct max1704x_dev_s *)dev;
return max1704x_getvcell(priv, value);
}
/****************************************************************************
* Name: max1704x_capacity
*
* Description:
* Battery capacity
*
****************************************************************************/
static int max1704x_capacity(struct battery_dev_s *dev, b16_t *value)
{
FAR struct max1704x_dev_s *priv = (FAR struct max1704x_dev_s *)dev;
return max1704x_getsoc(priv, value);
}
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: max1704x_initialize
*
* Description:
* Initialize the MAX1704x 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_I2C_MAX1704X - And the driver must be explictly selected.
* CONFIG_I2C_MAX17040 or CONFIG_I2C_MAX17041 - The driver must know which
* chip is on the board in order to scale the voltage correctly.
*
* Input Parameters:
* i2c - An instance of the I2C interface to use to communicate with the MAX1704x
* addr - The I2C address of the MAX1704x (Better be 0x36).
* frequency - The I2C frequency
*
* Returned Value:
* A pointer to the intialized lower-half driver instance. A NULL pointer
* is returned on a failure to initialize the MAX1704x lower half.
*
****************************************************************************/
FAR struct battery_dev_s *max1704x_initialize(FAR struct i2c_dev_s *i2c,
uint8_t addr, uint32_t frequency)
{
FAR struct max1704x_dev_s *priv;
#if 0
int ret;
#endif
/* Initialize the MAX1704x device structure */
priv = (FAR struct max1704x_dev_s *)kzalloc(sizeof(struct max1704x_dev_s));
if (priv)
{
/* Initialize the MAX1704x device structure */
sem_init(&priv->batsem, 0, 1);
priv->ops = &g_max1704xops;
priv->i2c = i2c;
priv->addr = addr;
priv->frequency = frequency;
/* Set the I2C frequency (ignoring the returned, actual frequency) */
(void)I2C_SETFREQUENCY(i2c, priv->frequency);
/* Reset the MAX1704x (mostly just to make sure that we can talk to it) */
#if 0
ret = max1704x_reset(priv);
if (ret < 0)
{
batdbg("Failed to reset the MAX1704x: %d\n", ret);
kfree(priv);
return NULL;
}
#endif
}
return (FAR struct battery_dev_s *)priv;
}
#endif /* CONFIG_BATTERY && CONFIG_I2C && CONFIG_I2C_MAX1704X */
