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power: supply: add driver for LT8491
LT8491 High Voltage Buck-Boost Battery Charge Controller with I2C Signed-off-by: John Erasmus Mari Geronimo <[email protected]>
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‎drivers/power/supply/Kconfig

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@@ -533,6 +533,15 @@ config CHARGER_LT3651
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Say Y to include support for the Analog Devices (Linear Technology)
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LT3651 battery charger which reports its status via GPIO lines.
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config CHARGER_LT8491
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tristate "Analog Devices LT8491 charger"
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depends on I2C
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help
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Say Y to include support for the Analog Devices (Linear Technology)
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LT8491 battery charge controller connected to I2C. The LT8491 is a
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high voltage buck-boost switching regulator battery charger
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controller.
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config CHARGER_LTC4162L
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tristate "LTC4162-L charger"
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depends on I2C

‎drivers/power/supply/Makefile

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@@ -72,6 +72,7 @@ obj-$(CONFIG_CHARGER_LP8788) += lp8788-charger.o
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obj-$(CONFIG_CHARGER_GPIO) += gpio-charger.o
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obj-$(CONFIG_CHARGER_MANAGER) += charger-manager.o
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obj-$(CONFIG_CHARGER_LT3651) += lt3651-charger.o
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obj-$(CONFIG_CHARGER_LT8491) += lt8491_charger.o
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obj-$(CONFIG_CHARGER_LTC4162L) += ltc4162-l-charger.o
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obj-$(CONFIG_CHARGER_MAX14577) += max14577_charger.o
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obj-$(CONFIG_CHARGER_DETECTOR_MAX14656) += max14656_charger_detector.o

‎drivers/power/supply/lt8491_charger.c

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@@ -0,0 +1,371 @@
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// SPDX-License-Identifier: GPL-2.0
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/*
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* Analog Devices LT8491 Battery Charger
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*
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* Copyright 2024 Analog Devices Inc.
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*/
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#include <linux/bitfield.h>
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#include <linux/device.h>
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#include <linux/errno.h>
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#include <linux/i2c.h>
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#include <linux/mod_devicetable.h>
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#include <linux/module.h>
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#include <linux/power_supply.h>
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#define LT8491_TELE_TBAT_REG 0x0
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#define LT8491_TELE_POUT_REG 0x2
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#define LT8491_TELE_PIN_REG 0x4
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#define LT8491_TELE_EFF_REG 0x6
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#define LT8491_TELE_IOUT_REG 0x8
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#define LT8491_TELE_IIN_REG 0xA
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#define LT8491_TELE_VBAT_REG 0xC
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#define LT8491_TELE_VIN_REG 0xE
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#define LT8491_TELE_VINR_REG 0x10
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#define LT8491_STAT_CHARGER_REG 0x12
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#define LT8491_STAT_CHRG_FAULTS_REG 0x19
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#define LT8491_CTRL_UPDATE_TELEM_REG 0x26
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#define LT8491_CFG_RSENSE1_REG 0x28
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#define LT8491_CFG_RIMON_OUT_REG 0x2A
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#define LT8491_CFG_RSENSE2_REG 0x2C
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#define LT8491_CFG_RDACO_REG 0x2E
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#define LT8491_CFG_RFBOUT1_REG 0x30
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#define LT8491_CFG_RFBOUT2_REG 0x32
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#define LT8491_CFG_RDACI_REG 0x34
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#define LT8491_CFG_RFBIN2_REG 0x36
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#define LT8491_CFG_RFBIN1_REG 0x38
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#define LT8491_CFG_TBAT_MIN_REG 0x40
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#define LT8491_CFG_TBAT_MAX_REG 0x41
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#define LT8491_MFR_DATA1_LSB_REG 0x5C
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#define LT8491_TELEM_ACTIVE_MASK BIT(6)
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#define LT8491_CHARGING_MASK BIT(2)
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#define LT8491_BAT_DISCON_FLT_MASK BIT(3)
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#define LT8491_MFR_DATA_LEN 0x3
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struct lt8491_info {
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struct i2c_client *client;
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struct power_supply *psp;
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};
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static int lt8491_read_serial_number(struct lt8491_info *info, char *strval)
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{
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int i, ret;
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u32 serial_number[LT8491_MFR_DATA_LEN];
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for (i = 0; i < LT8491_MFR_DATA_LEN; i++) {
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serial_number[i] = i2c_smbus_read_word_data(info->client, LT8491_MFR_DATA1_LSB_REG + i * 2);
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if (serial_number[i] < 0)
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return serial_number[i];
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}
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ret = sysfs_emit(strval, "%04x%04x%04x", serial_number[0], serial_number[1], serial_number[2]);
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if (ret < 0)
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return ret;
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return 0;
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}
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static int lt8491_get_property(struct power_supply *psy,
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enum power_supply_property psp,
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union power_supply_propval *val)
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{
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struct lt8491_info *info = power_supply_get_drvdata(psy);
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char strval[64];
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s16 ret;
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switch (psp) {
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case POWER_SUPPLY_PROP_STATUS:
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ret = i2c_smbus_read_byte_data(info->client, LT8491_STAT_CHARGER_REG);
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if (ret < 0)
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return ret;
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val->intval = FIELD_GET(LT8491_CHARGING_MASK, ret) ?
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POWER_SUPPLY_STATUS_CHARGING :
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POWER_SUPPLY_STATUS_NOT_CHARGING;
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return 0;
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case POWER_SUPPLY_PROP_VOLTAGE_NOW:
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ret = i2c_smbus_read_byte_data(info->client, LT8491_STAT_CHARGER_REG);
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if (ret < 0)
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return ret;
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if (!FIELD_GET(LT8491_TELEM_ACTIVE_MASK, ret)) {
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ret = i2c_smbus_write_byte_data(info->client, LT8491_CTRL_UPDATE_TELEM_REG, 0xAA);
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if (ret)
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return ret;
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}
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ret = i2c_smbus_read_word_data(info->client, LT8491_TELE_VBAT_REG);
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if (ret < 0)
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return ret;
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val->intval = ret * 10000;
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return 0;
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case POWER_SUPPLY_PROP_CURRENT_NOW:
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ret = i2c_smbus_read_byte_data(info->client, LT8491_STAT_CHARGER_REG);
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if (ret < 0)
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return ret;
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if (!FIELD_GET(LT8491_TELEM_ACTIVE_MASK, ret)) {
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ret = i2c_smbus_write_byte_data(info->client, LT8491_CTRL_UPDATE_TELEM_REG, 0xAA);
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if (ret)
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return ret;
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}
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ret = i2c_smbus_read_word_data(info->client, LT8491_TELE_IOUT_REG);
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if (ret < 0)
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return ret;
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val->intval = ret;
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return 0;
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case POWER_SUPPLY_PROP_POWER_NOW:
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ret = i2c_smbus_read_byte_data(info->client, LT8491_STAT_CHARGER_REG);
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if (ret < 0)
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return ret;
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if (!FIELD_GET(LT8491_TELEM_ACTIVE_MASK, ret)) {
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ret = i2c_smbus_write_byte_data(info->client, LT8491_CTRL_UPDATE_TELEM_REG, 0xAA);
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if (ret)
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return ret;
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}
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ret = i2c_smbus_read_word_data(info->client, LT8491_TELE_POUT_REG);
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if (ret < 0)
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return ret;
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val->intval = ret * 10000;
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return 0;
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case POWER_SUPPLY_PROP_TEMP:
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ret = i2c_smbus_read_byte_data(info->client, LT8491_STAT_CHARGER_REG);
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if (ret < 0)
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return ret;
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if (!FIELD_GET(LT8491_TELEM_ACTIVE_MASK, ret)) {
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ret = i2c_smbus_write_byte_data(info->client, LT8491_CTRL_UPDATE_TELEM_REG, 0xAA);
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if (ret)
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return ret;
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}
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ret = i2c_smbus_read_word_data(info->client, LT8491_TELE_TBAT_REG);
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if (ret < 0)
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return ret;
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val->intval = ret;
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return 0;
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case POWER_SUPPLY_PROP_TEMP_ALERT_MIN:
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ret = i2c_smbus_read_byte_data(info->client, LT8491_CFG_TBAT_MIN_REG);
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if (ret < 0)
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return ret;
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val->intval = ret * 10;
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return 0;
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case POWER_SUPPLY_PROP_TEMP_ALERT_MAX:
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ret = i2c_smbus_read_byte_data(info->client, LT8491_CFG_TBAT_MAX_REG);
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if (ret < 0)
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return ret;
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val->intval = ret * 10;
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return 0;
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case POWER_SUPPLY_PROP_MODEL_NAME:
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val->strval = "lt8491";
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return 0;
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case POWER_SUPPLY_PROP_MANUFACTURER:
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val->strval = "Analog Devices";
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return 0;
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case POWER_SUPPLY_PROP_SERIAL_NUMBER:
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ret = lt8491_read_serial_number(info, strval);
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if (ret)
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return ret;
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val->strval = strval;
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return 0;
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default:
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return -EINVAL;
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}
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}
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static int lt8491_set_property(struct power_supply *psy,
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enum power_supply_property psp,
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const union power_supply_propval *val)
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{
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struct lt8491_info *info = power_supply_get_drvdata(psy);
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switch (psp) {
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case POWER_SUPPLY_PROP_TEMP_ALERT_MIN:
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return i2c_smbus_write_byte_data(info->client,
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LT8491_CFG_TBAT_MIN_REG,
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val->intval / 10);
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case POWER_SUPPLY_PROP_TEMP_ALERT_MAX:
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return i2c_smbus_write_byte_data(info->client,
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LT8491_CFG_TBAT_MAX_REG,
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val->intval / 10);
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default:
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return -EINVAL;
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}
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}
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static int lt8491_property_is_writeable(struct power_supply *psy,
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enum power_supply_property psp)
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{
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switch (psp) {
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case POWER_SUPPLY_PROP_TEMP_ALERT_MIN:
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case POWER_SUPPLY_PROP_TEMP_ALERT_MAX:
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return 1;
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default:
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return 0;
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}
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}
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static enum power_supply_property lt8491_properties[] = {
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POWER_SUPPLY_PROP_STATUS,
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POWER_SUPPLY_PROP_VOLTAGE_NOW,
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POWER_SUPPLY_PROP_CURRENT_NOW,
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POWER_SUPPLY_PROP_POWER_NOW,
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POWER_SUPPLY_PROP_TEMP,
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POWER_SUPPLY_PROP_TEMP_ALERT_MIN,
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POWER_SUPPLY_PROP_TEMP_ALERT_MAX,
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POWER_SUPPLY_PROP_MODEL_NAME,
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POWER_SUPPLY_PROP_MANUFACTURER,
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POWER_SUPPLY_PROP_SERIAL_NUMBER,
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};
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static const struct power_supply_desc lt8491_desc = {
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.name = "lt8491",
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.type = POWER_SUPPLY_TYPE_BATTERY,
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.properties = lt8491_properties,
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.num_properties = ARRAY_SIZE(lt8491_properties),
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.get_property = lt8491_get_property,
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.set_property = lt8491_set_property,
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.property_is_writeable = lt8491_property_is_writeable,
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};
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static int lt8491_configure_resistor(struct lt8491_info *info,
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const char *propname, int divider,
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unsigned int reg)
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{
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struct device *dev = &info->client->dev;
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int ret;
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u32 val;
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ret = device_property_read_u32(dev, propname, &val);
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if (ret < 0)
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return dev_err_probe(dev, ret, "Missing %s property.\n", propname);
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return i2c_smbus_write_word_data(info->client, reg, val / divider);
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}
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static int lt8491_configure_telemetry(struct lt8491_info *info)
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{
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int ret;
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ret = lt8491_configure_resistor(info, "adi,rsense1-micro-ohms", 10,
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LT8491_CFG_RSENSE1_REG);
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if (ret)
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return ret;
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ret = lt8491_configure_resistor(info, "adi,rimon-out-ohms", 10,
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LT8491_CFG_RIMON_OUT_REG);
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if (ret)
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return ret;
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ret = lt8491_configure_resistor(info, "adi,rsense2-micro-ohms", 10,
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LT8491_CFG_RSENSE2_REG);
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if (ret)
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return ret;
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ret = lt8491_configure_resistor(info, "adi,rdaco-ohms", 10,
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LT8491_CFG_RDACO_REG);
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if (ret)
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return ret;
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ret = lt8491_configure_resistor(info, "adi,rfbout1-ohms", 100,
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LT8491_CFG_RFBOUT1_REG);
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if (ret)
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return ret;
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ret = lt8491_configure_resistor(info, "adi,rfbout2-ohms", 10,
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LT8491_CFG_RFBOUT2_REG);
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if (ret)
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return ret;
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ret = lt8491_configure_resistor(info, "adi,rdaci-ohms", 10,
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LT8491_CFG_RDACI_REG);
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if (ret)
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return ret;
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ret = lt8491_configure_resistor(info, "adi,rfbin2-ohms", 10,
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LT8491_CFG_RFBIN2_REG);
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if (ret)
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return ret;
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return lt8491_configure_resistor(info, "adi,rfbin1-ohms", 100,
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LT8491_CFG_RFBIN1_REG);
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}
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static int lt8491_probe(struct i2c_client *client)
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{
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struct device *dev = &client->dev;
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struct lt8491_info *info;
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struct power_supply_config psy_cfg = {};
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int ret;
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if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_BYTE_DATA |
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I2C_FUNC_SMBUS_READ_WORD_DATA))
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return -EOPNOTSUPP;
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info = devm_kzalloc(dev, sizeof(*info), GFP_KERNEL);
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if (!info)
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return -ENOMEM;
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info->client = client;
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psy_cfg.drv_data = info;
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ret = lt8491_configure_telemetry(info);
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if (ret)
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return ret;
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info->psp = power_supply_register(dev, &lt8491_desc, &psy_cfg);
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if (IS_ERR(info->psp))
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return dev_err_probe(dev, PTR_ERR(info->psp),
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"Failed to register power supply.\n");
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return 0;
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}
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static const struct i2c_device_id lt8491_id[] = {
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{ "lt8491", 0 },
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{ }
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};
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MODULE_DEVICE_TABLE(i2c, lt8491_id);
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static const struct of_device_id lt8491_of_match[] = {
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{ .compatible = "adi,lt8491" },
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{ }
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};
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MODULE_DEVICE_TABLE(of, lt8491_of_match);
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static struct i2c_driver lt8491_driver = {
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.driver = {
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.name = "lt8491",
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.of_match_table = lt8491_of_match,
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},
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.probe_new = lt8491_probe,
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.id_table = lt8491_id,
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};
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module_i2c_driver(lt8491_driver);
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MODULE_AUTHOR("John Erasmus Mari Geronimo <[email protected]");
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MODULE_DESCRIPTION("LT8491 battery charger");
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MODULE_LICENSE("GPL");

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