driver/battery/bq27541.c - chromiumos/platform/ec - Git at Google

 /* Copyright (c) 2013 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.
  *
  * Battery driver for BQ27541.
  */

 #include "battery.h"
 #include "console.h"
 #include "extpower.h"
 #include "i2c.h"
 #include "util.h"

 #define BQ27541_ADDR                0xaa
 #define BQ27541_TYPE_ID             0x0541

 #define REG_CTRL                    0x00
 #define REG_AT_RATE                 0x02
 #define REG_AT_RATE_TIME_TO_EMPTY   0x04
 #define REG_TEMPERATURE             0x06
 #define REG_VOLTAGE                 0x08
 #define REG_FLAGS                   0x0a
 #define REG_NOMINAL_CAPACITY        0x0c
 #define REG_FULL_AVAILABLE_CAPACITY 0x0e
 #define REG_REMAINING_CAPACITY      0x10
 #define REG_FULL_CHARGE_CAPACITY    0x12
 #define REG_AVERAGE_CURRENT         0x14
 #define REG_TIME_TO_EMPTY           0x16
 #define REG_TIME_TO_FULL            0x18
 #define REG_STANDBY_CURRENT         0x1a
 #define REG_STANDBY_TIME_TO_EMPTY   0x1c
 #define REG_MAX_LOAD_CURRENT        0x1e
 #define REG_MAX_LOAD_TIME_TO_EMPTY  0x20
 #define REG_AVAILABLE_ENERGY        0x22
 #define REG_AVERAGE_POEWR           0x24
 #define REG_TT_EAT_CONSTANT_POWER   0x26
 #define REG_CYCLE_COUNT             0x2a
 #define REG_STATE_OF_CHARGE         0x2c
 #define REG_DESIGN_CAPACITY         0x3c
 #define REG_DEVICE_NAME_LENGTH      0x62
 #define MAX_DEVICE_NAME_LENGTH      7
 #define REG_DEVICE_NAME             0x63
 #define REG_PROTECTOR               0x6d

 static int bq27541_read(int offset, int *data)
 {
 	return i2c_read16(I2C_PORT_BATTERY, BQ27541_ADDR, offset, data);
 }

 static int bq27541_read8(int offset, int *data)
 {
 	return i2c_read8(I2C_PORT_BATTERY, BQ27541_ADDR, offset, data);
 }

 static int bq27541_write(int offset, int data)
 {
 	return i2c_write16(I2C_PORT_BATTERY, BQ27541_ADDR, offset, data);
 }

 int bq27541_probe(void)
 {
 	int rv;
 	int dev_type;

 	rv = bq27541_write(REG_CTRL, 0x1);
 	rv |= bq27541_read(REG_CTRL, &dev_type);

 	if (rv)
 		return rv;
 	return (dev_type == BQ27541_TYPE_ID) ? EC_SUCCESS : EC_ERROR_UNKNOWN;
 }

 int battery_device_name(char *device_name, int buf_size)
 {
 	int rv, i, val;
 	int len = MIN(7, buf_size - 1);

 	rv = bq27541_read8(REG_DEVICE_NAME_LENGTH, &val);
 	if (rv)
 		return rv;
 	len = MIN(len, val);

 	for (i = 0; i < len; ++i) {
 		rv |= bq27541_read8(REG_DEVICE_NAME + i, &val);
 		device_name[i] = val;
 	}
 	device_name[i] = '\0';

 	return rv;
 }

 int battery_state_of_charge_abs(int *percent)
 {
 	return EC_ERROR_UNIMPLEMENTED;
 }

 int battery_remaining_capacity(int *capacity)
 {
 	return bq27541_read(REG_REMAINING_CAPACITY, capacity);
 }

 int battery_full_charge_capacity(int *capacity)
 {
 	return bq27541_read(REG_FULL_CHARGE_CAPACITY, capacity);
 }

 int battery_time_to_empty(int *minutes)
 {
 	return bq27541_read(REG_TIME_TO_EMPTY, minutes);
 }

 int battery_time_to_full(int *minutes)
 {
 	return bq27541_read(REG_TIME_TO_FULL, minutes);
 }

 int battery_cycle_count(int *count)
 {
 	return bq27541_read(REG_CYCLE_COUNT, count);
 }

 int battery_design_capacity(int *capacity)
 {
 	return bq27541_read(REG_DESIGN_CAPACITY, capacity);
 }

 int battery_time_at_rate(int rate, int *minutes)
 {
 	int rv;

 	rv = bq27541_write(REG_AT_RATE, rate);
 	if (rv)
 		return rv;
 	return bq27541_read(REG_AT_RATE_TIME_TO_EMPTY, minutes);
 }

 int battery_manufacturer_name(char *dest, int size)
 {
 	strzcpy(dest, "<unkn>", size);

 	return EC_SUCCESS;
 }

 int battery_device_chemistry(char *dest, int size)
 {
 	strzcpy(dest, "<unkn>", size);

 	return EC_SUCCESS;
 }

 int battery_serial_number(int *serial)
 {
 	*serial = 0x0BAD0BAD;

 	return EC_SUCCESS;
 }

 int battery_design_voltage(int *voltage)
 {
 	*voltage = battery_get_info()->voltage_normal;

 	return EC_SUCCESS;
 }

 /**
  * Check if battery allows charging.
  *
  * @param allowed	Non-zero if charging allowed; zero if not allowed.
  * @return non-zero if error.
  */
 static int battery_charging_allowed(int *allowed)
 {
 	int rv, val;

 	rv = bq27541_read(REG_FLAGS, &val);
 	if (rv)
 		return rv;
 	*allowed = (val & 0x100);
 	return EC_SUCCESS;
 }

 int battery_get_mode(int *mode)
 {
 	return EC_ERROR_UNIMPLEMENTED;
 }

 int battery_status(int *status)
 {
 	return EC_ERROR_UNIMPLEMENTED;
 }

 enum battery_present battery_is_present(void)
 {
 	int v;
 	if (bq27541_read(REG_TEMPERATURE, &v))
 		return BP_NOT_SURE;
 	return BP_YES;
 }

 void battery_get_params(struct batt_params *batt)
 {
 	int v;

 	/* Reset flags */
 	batt->flags = 0;

 	if (bq27541_read(REG_TEMPERATURE, &batt->temperature))
 		batt->flags |= BATT_FLAG_BAD_TEMPERATURE;
 	else
 		batt->flags |= BATT_FLAG_RESPONSIVE; /* Battery is responding */

 	if (bq27541_read8(REG_STATE_OF_CHARGE, &batt->state_of_charge))
 		batt->flags |= BATT_FLAG_BAD_STATE_OF_CHARGE;

 	if (bq27541_read(REG_VOLTAGE, &batt->voltage))
 		batt->flags |= BATT_FLAG_BAD_VOLTAGE;

 	v = 0;
 	if (bq27541_read(REG_AVERAGE_CURRENT, &v))
 		batt->flags |= BATT_FLAG_BAD_CURRENT;
 	batt->current = (int16_t)v;

 	/* Default to not desiring voltage and current */
 	batt->desired_voltage = batt->desired_current = 0;

 	v = 0;
 	if (battery_charging_allowed(&v)) {
 		batt->flags |= BATT_FLAG_BAD_ANY;
 	} else if (v) {
 		batt->flags |= BATT_FLAG_WANT_CHARGE;

 		/*
 		 * Desired voltage and current are not provided by the battery.
 		 * So ask for battery's max voltage and an arbitrarily large
 		 * current.
 		 */
 		batt->desired_voltage = battery_get_info()->voltage_max;
 		batt->desired_current = 4096;
 	}
 }

 /* Wait until battery is totally stable */
 int battery_wait_for_stable(void)
 {
 	/* TODO(crosbug.com/p/30426): implement me */
 	return EC_SUCCESS;
 }

 #ifdef CONFIG_BATTERY_REVIVE_DISCONNECT
 /*
  * Check if battery is in disconnect state, a state entered by pulling
  * BATT_DISCONN_N low, and clear that state if we have external power plugged
  * and no battery faults are detected. Disconnect state resembles battery
  * shutdown mode, but extra steps must be taken to get the battery out of this
  * mode.
  */
 enum battery_disconnect_state battery_get_disconnect_state(void)
 {
 	int val, rv;
 	/*
 	 * Take note if we find that the battery isn't in disconnect state,
 	 * and always return NOT_DISCONNECTED without probing the battery.
 	 * This assumes the battery will not go to disconnect state during
 	 * runtime.
 	 */
 	static int not_disconnected;

 	if (not_disconnected)
 		return BATTERY_NOT_DISCONNECTED;

 	if (extpower_is_present()) {
 		/* Check DSG_OFF bit */
 		rv = bq27541_read(REG_PROTECTOR, &val);
 		if (rv)
 			return BATTERY_DISCONNECT_ERROR;
 		if (!(val & (1 << 6))) {
 			not_disconnected = 1;
 			return BATTERY_NOT_DISCONNECTED;
 		}

 		/* DSG_OFF is set. Verify this is not due to a safety fault */
 		if (val & 0x3f)
 			return BATTERY_DISCONNECT_ERROR;
 		rv = bq27541_read(REG_FLAGS, &val);
 		if (rv)
 			return BATTERY_DISCONNECT_ERROR;
 		if (val & 0xfc60)
 			return BATTERY_DISCONNECT_ERROR;
 		return BATTERY_DISCONNECTED;
 	}
 	not_disconnected = 1;
 	return BATTERY_NOT_DISCONNECTED;
 }
 #endif /* CONFIG_BATTERY_REVIVE_DISCONNECT */
	/* Copyright (c) 2013 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.
	*
	* Battery driver for BQ27541.
	*/

	#include "battery.h"
	#include "console.h"
	#include "extpower.h"
	#include "i2c.h"
	#include "util.h"

	#define BQ27541_ADDR 0xaa
	#define BQ27541_TYPE_ID 0x0541

	#define REG_CTRL 0x00
	#define REG_AT_RATE 0x02
	#define REG_AT_RATE_TIME_TO_EMPTY 0x04
	#define REG_TEMPERATURE 0x06
	#define REG_VOLTAGE 0x08
	#define REG_FLAGS 0x0a
	#define REG_NOMINAL_CAPACITY 0x0c
	#define REG_FULL_AVAILABLE_CAPACITY 0x0e
	#define REG_REMAINING_CAPACITY 0x10
	#define REG_FULL_CHARGE_CAPACITY 0x12
	#define REG_AVERAGE_CURRENT 0x14
	#define REG_TIME_TO_EMPTY 0x16
	#define REG_TIME_TO_FULL 0x18
	#define REG_STANDBY_CURRENT 0x1a
	#define REG_STANDBY_TIME_TO_EMPTY 0x1c
	#define REG_MAX_LOAD_CURRENT 0x1e
	#define REG_MAX_LOAD_TIME_TO_EMPTY 0x20
	#define REG_AVAILABLE_ENERGY 0x22
	#define REG_AVERAGE_POEWR 0x24
	#define REG_TT_EAT_CONSTANT_POWER 0x26
	#define REG_CYCLE_COUNT 0x2a
	#define REG_STATE_OF_CHARGE 0x2c
	#define REG_DESIGN_CAPACITY 0x3c
	#define REG_DEVICE_NAME_LENGTH 0x62
	#define MAX_DEVICE_NAME_LENGTH 7
	#define REG_DEVICE_NAME 0x63
	#define REG_PROTECTOR 0x6d

	static int bq27541_read(int offset, int *data)
	{
	return i2c_read16(I2C_PORT_BATTERY, BQ27541_ADDR, offset, data);
	}

	static int bq27541_read8(int offset, int *data)
	{
	return i2c_read8(I2C_PORT_BATTERY, BQ27541_ADDR, offset, data);
	}

	static int bq27541_write(int offset, int data)
	{
	return i2c_write16(I2C_PORT_BATTERY, BQ27541_ADDR, offset, data);
	}

	int bq27541_probe(void)
	{
	int rv;
	int dev_type;

	rv = bq27541_write(REG_CTRL, 0x1);
	rv \|= bq27541_read(REG_CTRL, &dev_type);

	if (rv)
	return rv;
	return (dev_type == BQ27541_TYPE_ID) ? EC_SUCCESS : EC_ERROR_UNKNOWN;
	}

	int battery_device_name(char *device_name, int buf_size)
	{
	int rv, i, val;
	int len = MIN(7, buf_size - 1);

	rv = bq27541_read8(REG_DEVICE_NAME_LENGTH, &val);
	if (rv)
	return rv;
	len = MIN(len, val);

	for (i = 0; i < len; ++i) {
	rv \|= bq27541_read8(REG_DEVICE_NAME + i, &val);
	device_name[i] = val;
	}
	device_name[i] = '\0';

	return rv;
	}

	int battery_state_of_charge_abs(int *percent)
	{
	return EC_ERROR_UNIMPLEMENTED;
	}

	int battery_remaining_capacity(int *capacity)
	{
	return bq27541_read(REG_REMAINING_CAPACITY, capacity);
	}

	int battery_full_charge_capacity(int *capacity)
	{
	return bq27541_read(REG_FULL_CHARGE_CAPACITY, capacity);
	}

	int battery_time_to_empty(int *minutes)
	{
	return bq27541_read(REG_TIME_TO_EMPTY, minutes);
	}

	int battery_time_to_full(int *minutes)
	{
	return bq27541_read(REG_TIME_TO_FULL, minutes);
	}

	int battery_cycle_count(int *count)
	{
	return bq27541_read(REG_CYCLE_COUNT, count);
	}

	int battery_design_capacity(int *capacity)
	{
	return bq27541_read(REG_DESIGN_CAPACITY, capacity);
	}

	int battery_time_at_rate(int rate, int *minutes)
	{
	int rv;

	rv = bq27541_write(REG_AT_RATE, rate);
	if (rv)
	return rv;
	return bq27541_read(REG_AT_RATE_TIME_TO_EMPTY, minutes);
	}

	int battery_manufacturer_name(char *dest, int size)
	{
	strzcpy(dest, "<unkn>", size);

	return EC_SUCCESS;
	}

	int battery_device_chemistry(char *dest, int size)
	{
	strzcpy(dest, "<unkn>", size);

	return EC_SUCCESS;
	}

	int battery_serial_number(int *serial)
	{
	*serial = 0x0BAD0BAD;

	return EC_SUCCESS;
	}

	int battery_design_voltage(int *voltage)
	{
	*voltage = battery_get_info()->voltage_normal;

	return EC_SUCCESS;
	}

	/**
	* Check if battery allows charging.
	*
	* @param allowed Non-zero if charging allowed; zero if not allowed.
	* @return non-zero if error.
	*/
	static int battery_charging_allowed(int *allowed)
	{
	int rv, val;

	rv = bq27541_read(REG_FLAGS, &val);
	if (rv)
	return rv;
	*allowed = (val & 0x100);
	return EC_SUCCESS;
	}

	int battery_get_mode(int *mode)
	{
	return EC_ERROR_UNIMPLEMENTED;
	}

	int battery_status(int *status)
	{
	return EC_ERROR_UNIMPLEMENTED;
	}

	enum battery_present battery_is_present(void)
	{
	int v;
	if (bq27541_read(REG_TEMPERATURE, &v))
	return BP_NOT_SURE;
	return BP_YES;
	}

	void battery_get_params(struct batt_params *batt)
	{
	int v;

	/* Reset flags */
	batt->flags = 0;

	if (bq27541_read(REG_TEMPERATURE, &batt->temperature))
	batt->flags \|= BATT_FLAG_BAD_TEMPERATURE;
	else
	batt->flags \|= BATT_FLAG_RESPONSIVE; /* Battery is responding */

	if (bq27541_read8(REG_STATE_OF_CHARGE, &batt->state_of_charge))
	batt->flags \|= BATT_FLAG_BAD_STATE_OF_CHARGE;

	if (bq27541_read(REG_VOLTAGE, &batt->voltage))
	batt->flags \|= BATT_FLAG_BAD_VOLTAGE;

	v = 0;
	if (bq27541_read(REG_AVERAGE_CURRENT, &v))
	batt->flags \|= BATT_FLAG_BAD_CURRENT;
	batt->current = (int16_t)v;

	/* Default to not desiring voltage and current */
	batt->desired_voltage = batt->desired_current = 0;

	v = 0;
	if (battery_charging_allowed(&v)) {
	batt->flags \|= BATT_FLAG_BAD_ANY;
	} else if (v) {
	batt->flags \|= BATT_FLAG_WANT_CHARGE;

	/*
	* Desired voltage and current are not provided by the battery.
	* So ask for battery's max voltage and an arbitrarily large
	* current.
	*/
	batt->desired_voltage = battery_get_info()->voltage_max;
	batt->desired_current = 4096;
	}
	}

	/* Wait until battery is totally stable */
	int battery_wait_for_stable(void)
	{
	/* TODO(crosbug.com/p/30426): implement me */
	return EC_SUCCESS;
	}

	#ifdef CONFIG_BATTERY_REVIVE_DISCONNECT
	/*
	* Check if battery is in disconnect state, a state entered by pulling
	* BATT_DISCONN_N low, and clear that state if we have external power plugged
	* and no battery faults are detected. Disconnect state resembles battery
	* shutdown mode, but extra steps must be taken to get the battery out of this
	* mode.
	*/
	enum battery_disconnect_state battery_get_disconnect_state(void)
	{
	int val, rv;
	/*
	* Take note if we find that the battery isn't in disconnect state,
	* and always return NOT_DISCONNECTED without probing the battery.
	* This assumes the battery will not go to disconnect state during
	* runtime.
	*/
	static int not_disconnected;

	if (not_disconnected)
	return BATTERY_NOT_DISCONNECTED;

	if (extpower_is_present()) {
	/* Check DSG_OFF bit */
	rv = bq27541_read(REG_PROTECTOR, &val);
	if (rv)
	return BATTERY_DISCONNECT_ERROR;
	if (!(val & (1 << 6))) {
	not_disconnected = 1;
	return BATTERY_NOT_DISCONNECTED;
	}

	/* DSG_OFF is set. Verify this is not due to a safety fault */
	if (val & 0x3f)
	return BATTERY_DISCONNECT_ERROR;
	rv = bq27541_read(REG_FLAGS, &val);
	if (rv)
	return BATTERY_DISCONNECT_ERROR;
	if (val & 0xfc60)
	return BATTERY_DISCONNECT_ERROR;
	return BATTERY_DISCONNECTED;
	}
	not_disconnected = 1;
	return BATTERY_NOT_DISCONNECTED;
	}
	#endif /* CONFIG_BATTERY_REVIVE_DISCONNECT */