/**************************************************************************** * drivers/power/max1704x.c * Lower half driver for MAX1704x battery fuel gauge * * Copyright (C) 2012 Gregory Nutt. All rights reserved. * Author: Gregory Nutt * * 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 #include #include #include #include #include #include #include #include /* This driver requires: * * CONFIG_BATTERY - Upper half battery gauge 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_gauge_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_gauge_dev_s *dev, int *status); static int max1704x_online(struct battery_gauge_dev_s *dev, bool *status); static int max1704x_voltage(struct battery_gauge_dev_s *dev, b16_t *value); static int max1704x_capacity(struct battery_gauge_dev_s *dev, b16_t *value); /**************************************************************************** * Private Data ****************************************************************************/ static const struct battery_gauge_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 ACK ACK * REPEATED-START 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]; } /**************************************************************************** * Name: max1704x_putreg16 * * Description: * Write a 16-bit value to a MAX1704x register pair. * * START ACK 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_gauge_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_gauge_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_gauge_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_gauge_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 initializeed lower-half driver instance. A NULL pointer * is returned on a failure to initialize the MAX1704x lower half. * ****************************************************************************/ FAR struct battery_gauge_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 *)kmm_zalloc(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); kmm_free(priv); return NULL; } #endif } return (FAR struct battery_gauge_dev_s *)priv; } #endif /* CONFIG_BATTERY && CONFIG_I2C && CONFIG_I2C_MAX1704X */