power/supply: Add ltc4162-l-charger
authorMike Looijmans <mike.looijmans@topic.nl>
Thu, 7 Jan 2021 14:32:48 +0000 (15:32 +0100)
committerSebastian Reichel <sebastian.reichel@collabora.com>
Tue, 12 Jan 2021 23:46:34 +0000 (00:46 +0100)
Add support for the LTC4162-L Li-Ion battery charger. The driver allows
reading back telemetry and to set some charging options like the input
current limit.

Signed-off-by: Mike Looijmans <mike.looijmans@topic.nl>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
Documentation/ABI/testing/sysfs-class-power-ltc4162l [new file with mode: 0644]
drivers/power/supply/Kconfig
drivers/power/supply/Makefile
drivers/power/supply/ltc4162-l-charger.c [new file with mode: 0644]

diff --git a/Documentation/ABI/testing/sysfs-class-power-ltc4162l b/Documentation/ABI/testing/sysfs-class-power-ltc4162l
new file mode 100644 (file)
index 0000000..ba30db9
--- /dev/null
@@ -0,0 +1,82 @@
+What:          /sys/class/power_supply/ltc4162-l/charge_status
+Date:          Januari 2021
+KernelVersion: 5.11
+Description:
+               Detailed charge status information as reported by the chip.
+
+               Access: Read
+
+               Valid values:
+                       ilim_reg_active
+                       thermal_reg_active
+                       vin_uvcl_active
+                       iin_limit_active
+                       constant_current
+                       constant_voltage
+                       charger_off
+
+What:          /sys/class/power_supply/ltc4162-l/ibat
+Date:          Januari 2021
+KernelVersion: 5.11
+Description:
+               Battery input current as measured by the charger. Negative value
+               means that the battery is discharging.
+
+               Access: Read
+
+               Valid values: Signed value in microamps
+
+What:          /sys/class/power_supply/ltc4162-l/vbat
+Date:          Januari 2021
+KernelVersion: 5.11
+Description:
+               Battery voltage as measured by the charger.
+
+               Access: Read
+
+               Valid values: In microvolts
+
+What:          /sys/class/power_supply/ltc4162-l/vbat_avg
+Date:          Januari 2021
+KernelVersion: 5.11
+Description:
+               Battery voltage, averaged over time, as measured by the charger.
+
+               Access: Read
+
+               Valid values: In microvolts
+
+What:          /sys/class/power_supply/ltc4162-l/force_telemetry
+Date:          Januari 2021
+KernelVersion: 5.11
+Description:
+               To save battery current, the measurement system is disabled if
+               the battery is the only source of power. This affects all
+               voltage, current and temperature measurements.
+               Write a "1" to this to keep performing telemetry once every few
+               seconds, even when running on battery (as reported by the online
+               property, which is "1" when external power is available and "0"
+               when the system runs on battery).
+
+               Access: Read, Write
+
+               Valid values: 0 (disabled) or 1 (enabled)
+
+What:          /sys/class/power_supply/ltc4162-l/arm_ship_mode
+Date:          Januari 2021
+KernelVersion: 5.11
+Description:
+               The charger will normally drain the battery while inactive,
+               typically drawing about 54 microamps. Write a "1" to this
+               property to arm a special "ship" mode that extends shelf life
+               by reducing the leakage to about 2.8 microamps. The chip will
+               remain in this mode (and no longer respond to I2C commands)
+               until some external power-supply is attached raising the input
+               voltage above 1V. It will then automatically revert to "0".
+               Writing a "0" to the property cancels the "ship" mode request.
+               The ship mode, when armed, activates once the input voltage
+               drops below 1V.
+
+               Access: Read, Write
+
+               Valid values: 0 (disable) or 1 (enable)
index ef1d69b..c95ba6c 100644 (file)
@@ -513,6 +513,14 @@ config CHARGER_LT3651
          Say Y to include support for the Analog Devices (Linear Technology)
          LT3651 battery charger which reports its status via GPIO lines.
 
+config CHARGER_LTC4162L
+       tristate "LTC4162-L charger"
+       depends on I2C
+       select REGMAP_I2C
+       help
+         Say Y to include support for the Analog Devices (Linear Technology)
+         LTC4162-L battery charger connected to I2C.
+
 config CHARGER_MAX14577
        tristate "Maxim MAX14577/77836 battery charger driver"
        depends on MFD_MAX14577
index ae322b1..ae3d9c8 100644 (file)
@@ -70,6 +70,7 @@ obj-$(CONFIG_CHARGER_LP8788)  += lp8788-charger.o
 obj-$(CONFIG_CHARGER_GPIO)     += gpio-charger.o
 obj-$(CONFIG_CHARGER_MANAGER)  += charger-manager.o
 obj-$(CONFIG_CHARGER_LT3651)   += lt3651-charger.o
+obj-$(CONFIG_CHARGER_LTC4162L) += ltc4162-l-charger.o
 obj-$(CONFIG_CHARGER_MAX14577) += max14577_charger.o
 obj-$(CONFIG_CHARGER_DETECTOR_MAX14656)        += max14656_charger_detector.o
 obj-$(CONFIG_CHARGER_MAX77650) += max77650-charger.o
diff --git a/drivers/power/supply/ltc4162-l-charger.c b/drivers/power/supply/ltc4162-l-charger.c
new file mode 100644 (file)
index 0000000..cded648
--- /dev/null
@@ -0,0 +1,931 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ *  Driver for Analog Devices (Linear Technology) LTC4162-L charger IC.
+ *  Copyright (C) 2020, Topic Embedded Products
+ */
+
+#include <linux/module.h>
+#include <linux/delay.h>
+#include <linux/of_device.h>
+#include <linux/pm_runtime.h>
+#include <linux/power_supply.h>
+#include <linux/i2c.h>
+#include <linux/regmap.h>
+
+/* Registers (names based on what datasheet uses) */
+#define LTC4162L_EN_LIMIT_ALERTS_REG           0x0D
+#define LTC4162L_EN_CHARGER_STATE_ALERTS_REG   0x0E
+#define LTC4162L_EN_CHARGE_STATUS_ALERTS_REG   0x0F
+#define LTC4162L_CONFIG_BITS_REG               0x14
+#define LTC4162L_IIN_LIMIT_TARGET              0x15
+#define LTC4162L_ARM_SHIP_MODE                 0x19
+#define LTC4162L_CHARGE_CURRENT_SETTING                0X1A
+#define LTC4162L_VCHARGE_SETTING               0X1B
+#define LTC4162L_C_OVER_X_THRESHOLD            0x1C
+#define LTC4162L_MAX_CV_TIME                   0X1D
+#define LTC4162L_MAX_CHARGE_TIME               0X1E
+#define LTC4162L_CHARGER_CONFIG_BITS           0x29
+#define LTC4162L_CHARGER_STATE                 0x34
+#define LTC4162L_CHARGE_STATUS                 0x35
+#define LTC4162L_LIMIT_ALERTS_REG              0x36
+#define LTC4162L_CHARGER_STATE_ALERTS_REG      0x37
+#define LTC4162L_CHARGE_STATUS_ALERTS_REG      0x38
+#define LTC4162L_SYSTEM_STATUS_REG             0x39
+#define LTC4162L_VBAT                          0x3A
+#define LTC4162L_VIN                           0x3B
+#define LTC4162L_VOUT                          0x3C
+#define LTC4162L_IBAT                          0x3D
+#define LTC4162L_IIN                           0x3E
+#define LTC4162L_DIE_TEMPERATURE               0x3F
+#define LTC4162L_THERMISTOR_VOLTAGE            0x40
+#define LTC4162L_BSR                           0x41
+#define LTC4162L_JEITA_REGION                  0x42
+#define LTC4162L_CHEM_CELLS_REG                        0x43
+#define LTC4162L_ICHARGE_DAC                   0x44
+#define LTC4162L_VCHARGE_DAC                   0x45
+#define LTC4162L_IIN_LIMIT_DAC                 0x46
+#define LTC4162L_VBAT_FILT                     0x47
+#define LTC4162L_INPUT_UNDERVOLTAGE_DAC                0x4B
+
+/* Enumeration as in datasheet. Individual bits are mutually exclusive. */
+enum ltc4162l_state {
+       battery_detection = 2048,
+       charger_suspended = 256,
+       precharge = 128,   /* trickle on low bat voltage */
+       cc_cv_charge = 64, /* normal charge */
+       ntc_pause = 32,
+       timer_term = 16,
+       c_over_x_term = 8, /* battery is full */
+       max_charge_time_fault = 4,
+       bat_missing_fault = 2,
+       bat_short_fault = 1
+};
+
+/* Individual bits are mutually exclusive. Only active in charging states.*/
+enum ltc4162l_charge_status {
+       ilim_reg_active = 32,
+       thermal_reg_active = 16,
+       vin_uvcl_active = 8,
+       iin_limit_active = 4,
+       constant_current = 2,
+       constant_voltage = 1,
+       charger_off = 0
+};
+
+/* Magic number to write to ARM_SHIP_MODE register */
+#define LTC4162L_ARM_SHIP_MODE_MAGIC 21325
+
+struct ltc4162l_info {
+       struct i2c_client       *client;
+       struct regmap           *regmap;
+       struct power_supply     *charger;
+       u32 rsnsb;      /* Series resistor that sets charge current, microOhm */
+       u32 rsnsi;      /* Series resistor to measure input current, microOhm */
+       u8 cell_count;  /* Number of connected cells, 0 while unknown */
+};
+
+static u8 ltc4162l_get_cell_count(struct ltc4162l_info *info)
+{
+       int ret;
+       unsigned int val;
+
+       /* Once read successfully */
+       if (info->cell_count)
+               return info->cell_count;
+
+       ret = regmap_read(info->regmap, LTC4162L_CHEM_CELLS_REG, &val);
+       if (ret)
+               return 0;
+
+       /* Lower 4 bits is the cell count, or 0 if the chip doesn't know yet */
+       val &= 0x0f;
+       if (!val)
+               return 0;
+
+       /* Once determined, keep the value */
+       info->cell_count = val;
+
+       return val;
+};
+
+/* Convert enum value to POWER_SUPPLY_STATUS value */
+static int ltc4162l_state_decode(enum ltc4162l_state value)
+{
+       switch (value) {
+       case precharge:
+       case cc_cv_charge:
+               return POWER_SUPPLY_STATUS_CHARGING;
+       case c_over_x_term:
+               return POWER_SUPPLY_STATUS_FULL;
+       case bat_missing_fault:
+       case bat_short_fault:
+               return POWER_SUPPLY_STATUS_UNKNOWN;
+       default:
+               return POWER_SUPPLY_STATUS_NOT_CHARGING;
+       }
+};
+
+static int ltc4162l_get_status(struct ltc4162l_info *info,
+                              union power_supply_propval *val)
+{
+       unsigned int regval;
+       int ret;
+
+       ret = regmap_read(info->regmap, LTC4162L_CHARGER_STATE, &regval);
+       if (ret) {
+               dev_err(&info->client->dev, "Failed to read CHARGER_STATE\n");
+               return ret;
+       }
+
+       val->intval = ltc4162l_state_decode(regval);
+
+       return 0;
+}
+
+static int ltc4162l_charge_status_decode(enum ltc4162l_charge_status value)
+{
+       if (!value)
+               return POWER_SUPPLY_CHARGE_TYPE_NONE;
+
+       /* constant voltage/current and input_current limit are "fast" modes */
+       if (value <= iin_limit_active)
+               return POWER_SUPPLY_CHARGE_TYPE_FAST;
+
+       /* Anything that's not fast we'll return as trickle */
+       return POWER_SUPPLY_CHARGE_TYPE_TRICKLE;
+}
+
+static int ltc4162l_get_charge_type(struct ltc4162l_info *info,
+                                   union power_supply_propval *val)
+{
+       unsigned int regval;
+       int ret;
+
+       ret = regmap_read(info->regmap, LTC4162L_CHARGE_STATUS, &regval);
+       if (ret)
+               return ret;
+
+       val->intval = ltc4162l_charge_status_decode(regval);
+
+       return 0;
+}
+
+static int ltc4162l_state_to_health(enum ltc4162l_state value)
+{
+       switch (value) {
+       case ntc_pause:
+               return POWER_SUPPLY_HEALTH_OVERHEAT;
+       case timer_term:
+               return POWER_SUPPLY_HEALTH_SAFETY_TIMER_EXPIRE;
+       case max_charge_time_fault:
+               return POWER_SUPPLY_HEALTH_WATCHDOG_TIMER_EXPIRE;
+       case bat_missing_fault:
+               return POWER_SUPPLY_HEALTH_UNSPEC_FAILURE;
+       case bat_short_fault:
+               return POWER_SUPPLY_HEALTH_DEAD;
+       default:
+               return POWER_SUPPLY_HEALTH_GOOD;
+       }
+}
+
+static int ltc4162l_get_health(struct ltc4162l_info *info,
+                              union power_supply_propval *val)
+{
+       unsigned int regval;
+       int ret;
+
+       ret = regmap_read(info->regmap, LTC4162L_CHARGER_STATE, &regval);
+       if (ret)
+               return ret;
+
+       val->intval = ltc4162l_state_to_health(regval);
+
+       return 0;
+}
+
+static int ltc4162l_get_online(struct ltc4162l_info *info,
+                              union power_supply_propval *val)
+{
+       unsigned int regval;
+       int ret;
+
+       ret = regmap_read(info->regmap, LTC4162L_SYSTEM_STATUS_REG, &regval);
+       if (ret)
+               return ret;
+
+       /* BIT(2) indicates if input voltage is sufficient to charge */
+       val->intval = !!(regval & BIT(2));
+
+       return 0;
+}
+
+static int ltc4162l_get_vbat(struct ltc4162l_info *info,
+                                 unsigned int reg,
+                                 union power_supply_propval *val)
+{
+       unsigned int regval;
+       int ret;
+
+       ret = regmap_read(info->regmap, reg, &regval);
+       if (ret)
+               return ret;
+
+       /* cell_count × 192.4μV/LSB */
+       regval *= 1924;
+       regval *= ltc4162l_get_cell_count(info);
+       regval /= 10;
+       val->intval = regval;
+
+       return 0;
+}
+
+static int ltc4162l_get_ibat(struct ltc4162l_info *info,
+                            union power_supply_propval *val)
+{
+       unsigned int regval;
+       int ret;
+
+       ret = regmap_read(info->regmap, LTC4162L_IBAT, &regval);
+       if (ret)
+               return ret;
+
+       /* Signed 16-bit number, 1.466μV / RSNSB amperes/LSB. */
+       ret = (s16)(regval & 0xFFFF);
+       val->intval = 100 * mult_frac(ret, 14660, (int)info->rsnsb);
+
+       return 0;
+}
+
+
+static int ltc4162l_get_input_voltage(struct ltc4162l_info *info,
+                                     union power_supply_propval *val)
+{
+       unsigned int regval;
+       int ret;
+
+       ret = regmap_read(info->regmap, LTC4162L_VIN, &regval);
+       if (ret)
+               return ret;
+
+       /* 1.649mV/LSB */
+       val->intval =  regval * 1694;
+
+       return 0;
+}
+
+static int ltc4162l_get_input_current(struct ltc4162l_info *info,
+                                     union power_supply_propval *val)
+{
+       unsigned int regval;
+       int ret;
+
+       ret = regmap_read(info->regmap, LTC4162L_IIN, &regval);
+       if (ret)
+               return ret;
+
+       /* Signed 16-bit number, 1.466μV / RSNSI amperes/LSB. */
+       ret = (s16)(regval & 0xFFFF);
+       ret *= 14660;
+       ret /= info->rsnsi;
+       ret *= 100;
+
+       val->intval = ret;
+
+       return 0;
+}
+
+static int ltc4162l_get_icharge(struct ltc4162l_info *info,
+                               unsigned int reg,
+                               union power_supply_propval *val)
+{
+       unsigned int regval;
+       int ret;
+
+       ret = regmap_read(info->regmap, reg, &regval);
+       if (ret)
+               return ret;
+
+       regval &= BIT(6) - 1; /* Only the lower 5 bits */
+
+       /* The charge current servo level: (icharge_dac + 1) × 1mV/RSNSB */
+       ++regval;
+       val->intval = 10000u * mult_frac(regval, 100000u, info->rsnsb);
+
+       return 0;
+}
+
+static int ltc4162l_set_icharge(struct ltc4162l_info *info,
+                               unsigned int reg,
+                               unsigned int value)
+{
+       value = mult_frac(value, info->rsnsb, 100000u);
+       value /= 10000u;
+
+       /* Round to lowest possible */
+       if (value)
+               --value;
+
+       if (value > 31)
+               return -EINVAL;
+
+       return regmap_write(info->regmap, reg, value);
+}
+
+
+static int ltc4162l_get_vcharge(struct ltc4162l_info *info,
+                               unsigned int reg,
+                               union power_supply_propval *val)
+{
+       unsigned int regval;
+       int ret;
+       u32 voltage;
+
+       ret = regmap_read(info->regmap, reg, &regval);
+       if (ret)
+               return ret;
+
+       regval &= BIT(6) - 1; /* Only the lower 5 bits */
+
+       /*
+        * charge voltage setting can be computed from
+        * cell_count × (vcharge_setting × 12.5mV + 3.8125V)
+        * where vcharge_setting ranges from 0 to 31 (4.2V max).
+        */
+       voltage = 3812500 + (regval * 12500);
+       voltage *= ltc4162l_get_cell_count(info);
+       val->intval = voltage;
+
+       return 0;
+}
+
+static int ltc4162l_set_vcharge(struct ltc4162l_info *info,
+                               unsigned int reg,
+                               unsigned int value)
+{
+       u8 cell_count = ltc4162l_get_cell_count(info);
+
+       if (!cell_count)
+               return -EBUSY; /* Not available yet, try again later */
+
+       value /= cell_count;
+
+       if (value < 3812500)
+               return -EINVAL;
+
+       value -= 3812500;
+       value /= 12500;
+
+       if (value > 31)
+               return -EINVAL;
+
+       return regmap_write(info->regmap, reg, value);
+}
+
+static int ltc4162l_get_iin_limit_dac(struct ltc4162l_info *info,
+                                    union power_supply_propval *val)
+{
+       unsigned int regval;
+       int ret;
+
+       ret = regmap_read(info->regmap, LTC4162L_IIN_LIMIT_DAC, &regval);
+       if (ret)
+               return ret;
+
+       regval &= BIT(6) - 1; /* Only 6 bits */
+
+       /* (iin_limit_dac + 1) × 500μV / RSNSI */
+       ++regval;
+       regval *= 5000000u;
+       regval /= info->rsnsi;
+       val->intval = 100u * regval;
+
+       return 0;
+}
+
+static int ltc4162l_set_iin_limit(struct ltc4162l_info *info,
+                                 unsigned int value)
+{
+       unsigned int regval;
+
+       regval = mult_frac(value, info->rsnsi, 50000u);
+       regval /= 10000u;
+       if (regval)
+               --regval;
+       if (regval > 63)
+               regval = 63;
+
+       return regmap_write(info->regmap, LTC4162L_IIN_LIMIT_TARGET, regval);
+}
+
+static int ltc4162l_get_die_temp(struct ltc4162l_info *info,
+                                union power_supply_propval *val)
+{
+       unsigned int regval;
+       int ret;
+
+       ret = regmap_read(info->regmap, LTC4162L_DIE_TEMPERATURE, &regval);
+       if (ret)
+               return ret;
+
+       /* die_temp × 0.0215°C/LSB - 264.4°C */
+       ret = (s16)(regval & 0xFFFF);
+       ret *= 215;
+       ret /= 100; /* Centidegrees scale */
+       ret -= 26440;
+       val->intval = ret;
+
+       return 0;
+}
+
+static int ltc4162l_get_term_current(struct ltc4162l_info *info,
+                                    union power_supply_propval *val)
+{
+       unsigned int regval;
+       int ret;
+
+       ret = regmap_read(info->regmap, LTC4162L_CHARGER_CONFIG_BITS, &regval);
+       if (ret)
+               return ret;
+
+       /* Check if C_OVER_X_THRESHOLD is enabled */
+       if (!(regval & BIT(2))) {
+               val->intval = 0;
+               return 0;
+       }
+
+       ret = regmap_read(info->regmap, LTC4162L_C_OVER_X_THRESHOLD, &regval);
+       if (ret)
+               return ret;
+
+       /* 1.466μV / RSNSB amperes/LSB */
+       regval *= 14660u;
+       regval /= info->rsnsb;
+       val->intval = 100 * regval;
+
+       return 0;
+}
+
+static int ltc4162l_set_term_current(struct ltc4162l_info *info,
+                                    unsigned int value)
+{
+       int ret;
+       unsigned int regval;
+
+       if (!value) {
+               /* Disable en_c_over_x_term when set to zero */
+               return regmap_update_bits(info->regmap,
+                                         LTC4162L_CHARGER_CONFIG_BITS,
+                                         BIT(2), 0);
+       }
+
+       regval = mult_frac(value, info->rsnsb, 14660u);
+       regval /= 100u;
+
+       ret =  regmap_write(info->regmap, LTC4162L_C_OVER_X_THRESHOLD, regval);
+       if (ret)
+               return ret;
+
+       /* Set en_c_over_x_term after changing the threshold value */
+       return regmap_update_bits(info->regmap, LTC4162L_CHARGER_CONFIG_BITS,
+                                 BIT(2), BIT(2));
+}
+
+/* Custom properties */
+static const char * const ltc4162l_charge_status_name[] = {
+       "ilim_reg_active", /* 32 */
+       "thermal_reg_active",
+       "vin_uvcl_active",
+       "iin_limit_active",
+       "constant_current",
+       "constant_voltage",
+       "charger_off" /* 0 */
+};
+
+static ssize_t charge_status_show(struct device *dev,
+                                 struct device_attribute *attr, char *buf)
+{
+       struct power_supply *psy = to_power_supply(dev);
+       struct ltc4162l_info *info = power_supply_get_drvdata(psy);
+       const char *result = ltc4162l_charge_status_name[
+                               ARRAY_SIZE(ltc4162l_charge_status_name) - 1];
+       unsigned int regval;
+       unsigned int mask;
+       unsigned int index;
+       int ret;
+
+       ret = regmap_read(info->regmap, LTC4162L_CHARGE_STATUS, &regval);
+       if (ret)
+               return ret;
+
+       /* Only one bit is set according to datasheet, let's be safe here */
+       for (mask = 32, index = 0; mask != 0; mask >>= 1, ++index) {
+               if (regval & mask) {
+                       result = ltc4162l_charge_status_name[index];
+                       break;
+               }
+       }
+
+       return sprintf(buf, "%s\n", result);
+}
+static DEVICE_ATTR_RO(charge_status);
+
+static ssize_t vbat_show(struct device *dev,
+                                 struct device_attribute *attr, char *buf)
+{
+       struct power_supply *psy = to_power_supply(dev);
+       struct ltc4162l_info *info = power_supply_get_drvdata(psy);
+       union power_supply_propval val;
+       int ret;
+
+       ret = ltc4162l_get_vbat(info, LTC4162L_VBAT, &val);
+       if (ret)
+               return ret;
+
+       return sprintf(buf, "%d\n", val.intval);
+}
+static DEVICE_ATTR_RO(vbat);
+
+static ssize_t vbat_avg_show(struct device *dev,
+                                 struct device_attribute *attr, char *buf)
+{
+       struct power_supply *psy = to_power_supply(dev);
+       struct ltc4162l_info *info = power_supply_get_drvdata(psy);
+       union power_supply_propval val;
+       int ret;
+
+       ret = ltc4162l_get_vbat(info, LTC4162L_VBAT_FILT, &val);
+       if (ret)
+               return ret;
+
+       return sprintf(buf, "%d\n", val.intval);
+}
+static DEVICE_ATTR_RO(vbat_avg);
+
+static ssize_t ibat_show(struct device *dev,
+                                 struct device_attribute *attr, char *buf)
+{
+       struct power_supply *psy = to_power_supply(dev);
+       struct ltc4162l_info *info = power_supply_get_drvdata(psy);
+       union power_supply_propval val;
+       int ret;
+
+       ret = ltc4162l_get_ibat(info, &val);
+       if (ret)
+               return ret;
+
+       return sprintf(buf, "%d\n", val.intval);
+}
+static DEVICE_ATTR_RO(ibat);
+
+static ssize_t force_telemetry_show(struct device *dev,
+                                   struct device_attribute *attr, char *buf)
+{
+       struct power_supply *psy = to_power_supply(dev);
+       struct ltc4162l_info *info = power_supply_get_drvdata(psy);
+       unsigned int regval;
+       int ret;
+
+       ret = regmap_read(info->regmap, LTC4162L_CONFIG_BITS_REG, &regval);
+       if (ret)
+               return ret;
+
+       return sprintf(buf, "%u\n", regval & BIT(2) ? 1 : 0);
+}
+
+static ssize_t force_telemetry_store(struct device *dev,
+       struct device_attribute *attr,
+       const char *buf,
+       size_t count)
+{
+       struct power_supply *psy = to_power_supply(dev);
+       struct ltc4162l_info *info = power_supply_get_drvdata(psy);
+       int ret;
+       unsigned int value;
+
+       ret = kstrtouint(buf, 0, &value);
+       if (ret < 0)
+               return ret;
+
+       ret = regmap_update_bits(info->regmap, LTC4162L_CONFIG_BITS_REG,
+                                BIT(2), value ? BIT(2) : 0);
+       if (ret < 0)
+               return ret;
+
+       return count;
+}
+
+static DEVICE_ATTR_RW(force_telemetry);
+
+static ssize_t arm_ship_mode_show(struct device *dev,
+                                   struct device_attribute *attr, char *buf)
+{
+       struct power_supply *psy = to_power_supply(dev);
+       struct ltc4162l_info *info = power_supply_get_drvdata(psy);
+       unsigned int regval;
+       int ret;
+
+       ret = regmap_read(info->regmap, LTC4162L_ARM_SHIP_MODE, &regval);
+       if (ret)
+               return ret;
+
+       return sprintf(buf, "%u\n",
+               regval == LTC4162L_ARM_SHIP_MODE_MAGIC ? 1 : 0);
+}
+
+static ssize_t arm_ship_mode_store(struct device *dev,
+       struct device_attribute *attr,
+       const char *buf,
+       size_t count)
+{
+       struct power_supply *psy = to_power_supply(dev);
+       struct ltc4162l_info *info = power_supply_get_drvdata(psy);
+       int ret;
+       unsigned int value;
+
+       ret = kstrtouint(buf, 0, &value);
+       if (ret < 0)
+               return ret;
+
+       ret = regmap_write(info->regmap, LTC4162L_ARM_SHIP_MODE,
+                               value ? LTC4162L_ARM_SHIP_MODE_MAGIC : 0);
+       if (ret < 0)
+               return ret;
+
+       return count;
+}
+
+static DEVICE_ATTR_RW(arm_ship_mode);
+
+static struct attribute *ltc4162l_sysfs_entries[] = {
+       &dev_attr_charge_status.attr,
+       &dev_attr_ibat.attr,
+       &dev_attr_vbat.attr,
+       &dev_attr_vbat_avg.attr,
+       &dev_attr_force_telemetry.attr,
+       &dev_attr_arm_ship_mode.attr,
+       NULL,
+};
+
+static struct attribute_group ltc4162l_attr_group = {
+       .name   = NULL, /* put in device directory */
+       .attrs  = ltc4162l_sysfs_entries,
+};
+
+static const struct attribute_group *ltc4162l_attr_groups[] = {
+       &ltc4162l_attr_group,
+       NULL,
+};
+
+static int ltc4162l_get_property(struct power_supply *psy,
+                                enum power_supply_property psp,
+                                union power_supply_propval *val)
+{
+       struct ltc4162l_info *info = power_supply_get_drvdata(psy);
+
+       switch (psp) {
+       case POWER_SUPPLY_PROP_STATUS:
+               return ltc4162l_get_status(info, val);
+       case POWER_SUPPLY_PROP_CHARGE_TYPE:
+               return ltc4162l_get_charge_type(info, val);
+       case POWER_SUPPLY_PROP_HEALTH:
+               return ltc4162l_get_health(info, val);
+       case POWER_SUPPLY_PROP_ONLINE:
+               return ltc4162l_get_online(info, val);
+       case POWER_SUPPLY_PROP_VOLTAGE_NOW:
+               return ltc4162l_get_input_voltage(info, val);
+       case POWER_SUPPLY_PROP_CURRENT_NOW:
+               return ltc4162l_get_input_current(info, val);
+       case POWER_SUPPLY_PROP_CONSTANT_CHARGE_CURRENT:
+               return ltc4162l_get_icharge(info,
+                               LTC4162L_ICHARGE_DAC, val);
+       case POWER_SUPPLY_PROP_CONSTANT_CHARGE_CURRENT_MAX:
+               return ltc4162l_get_icharge(info,
+                               LTC4162L_CHARGE_CURRENT_SETTING, val);
+       case POWER_SUPPLY_PROP_CONSTANT_CHARGE_VOLTAGE:
+               return ltc4162l_get_vcharge(info,
+                               LTC4162L_VCHARGE_DAC, val);
+       case POWER_SUPPLY_PROP_CONSTANT_CHARGE_VOLTAGE_MAX:
+               return ltc4162l_get_vcharge(info,
+                               LTC4162L_VCHARGE_SETTING, val);
+       case POWER_SUPPLY_PROP_INPUT_CURRENT_LIMIT:
+               return ltc4162l_get_iin_limit_dac(info, val);
+       case POWER_SUPPLY_PROP_TEMP:
+               return ltc4162l_get_die_temp(info, val);
+       case POWER_SUPPLY_PROP_CHARGE_TERM_CURRENT:
+               return ltc4162l_get_term_current(info, val);
+       default:
+               return -EINVAL;
+       }
+}
+
+static int ltc4162l_set_property(struct power_supply *psy,
+                                        enum power_supply_property psp,
+                                        const union power_supply_propval *val)
+{
+       struct ltc4162l_info *info = power_supply_get_drvdata(psy);
+
+       switch (psp) {
+       case POWER_SUPPLY_PROP_CONSTANT_CHARGE_CURRENT_MAX:
+               return ltc4162l_set_icharge(info,
+                               LTC4162L_CHARGE_CURRENT_SETTING, val->intval);
+       case POWER_SUPPLY_PROP_CONSTANT_CHARGE_VOLTAGE_MAX:
+               return ltc4162l_set_vcharge(info,
+                               LTC4162L_VCHARGE_SETTING, val->intval);
+       case POWER_SUPPLY_PROP_INPUT_CURRENT_LIMIT:
+               return ltc4162l_set_iin_limit(info, val->intval);
+       case POWER_SUPPLY_PROP_CHARGE_TERM_CURRENT:
+               return ltc4162l_set_term_current(info, val->intval);
+       default:
+               return -EINVAL;
+       }
+}
+
+static int ltc4162l_property_is_writeable(struct power_supply *psy,
+                                               enum power_supply_property psp)
+{
+       switch (psp) {
+       case POWER_SUPPLY_PROP_CONSTANT_CHARGE_CURRENT_MAX:
+       case POWER_SUPPLY_PROP_CONSTANT_CHARGE_VOLTAGE_MAX:
+       case POWER_SUPPLY_PROP_INPUT_CURRENT_LIMIT:
+       case POWER_SUPPLY_PROP_CHARGE_TERM_CURRENT:
+               return 1;
+       default:
+               return 0;
+       }
+}
+
+/* Charger power supply property routines */
+static enum power_supply_property ltc4162l_properties[] = {
+       POWER_SUPPLY_PROP_STATUS,
+       POWER_SUPPLY_PROP_CHARGE_TYPE,
+       POWER_SUPPLY_PROP_HEALTH,
+       POWER_SUPPLY_PROP_ONLINE,
+       POWER_SUPPLY_PROP_VOLTAGE_NOW,
+       POWER_SUPPLY_PROP_CURRENT_NOW,
+       POWER_SUPPLY_PROP_CONSTANT_CHARGE_CURRENT,
+       POWER_SUPPLY_PROP_CONSTANT_CHARGE_CURRENT_MAX,
+       POWER_SUPPLY_PROP_CONSTANT_CHARGE_VOLTAGE,
+       POWER_SUPPLY_PROP_CONSTANT_CHARGE_VOLTAGE_MAX,
+       POWER_SUPPLY_PROP_INPUT_CURRENT_LIMIT,
+       POWER_SUPPLY_PROP_TEMP,
+       POWER_SUPPLY_PROP_CHARGE_TERM_CURRENT,
+};
+
+static const struct power_supply_desc ltc4162l_desc = {
+       .name           = "ltc4162-l",
+       .type           = POWER_SUPPLY_TYPE_MAINS,
+       .properties     = ltc4162l_properties,
+       .num_properties = ARRAY_SIZE(ltc4162l_properties),
+       .get_property   = ltc4162l_get_property,
+       .set_property   = ltc4162l_set_property,
+       .property_is_writeable = ltc4162l_property_is_writeable,
+};
+
+static bool ltc4162l_is_writeable_reg(struct device *dev, unsigned int reg)
+{
+       /* all registers up to this one are writeable */
+       if (reg <= LTC4162L_CHARGER_CONFIG_BITS)
+               return true;
+
+       /* The ALERTS registers can be written to clear alerts */
+       if (reg >= LTC4162L_LIMIT_ALERTS_REG &&
+           reg <= LTC4162L_CHARGE_STATUS_ALERTS_REG)
+               return true;
+
+       return false;
+}
+
+static bool ltc4162l_is_volatile_reg(struct device *dev, unsigned int reg)
+{
+       /* all registers after this one are read-only status registers */
+       return reg > LTC4162L_CHARGER_CONFIG_BITS;
+}
+
+static const struct regmap_config ltc4162l_regmap_config = {
+       .reg_bits       = 8,
+       .val_bits       = 16,
+       .val_format_endian = REGMAP_ENDIAN_LITTLE,
+       .writeable_reg  = ltc4162l_is_writeable_reg,
+       .volatile_reg   = ltc4162l_is_volatile_reg,
+       .max_register   = LTC4162L_INPUT_UNDERVOLTAGE_DAC,
+       .cache_type     = REGCACHE_RBTREE,
+};
+
+static void ltc4162l_clear_interrupts(struct ltc4162l_info *info)
+{
+       /* Acknowledge interrupt to chip by clearing all events */
+       regmap_write(info->regmap, LTC4162L_LIMIT_ALERTS_REG, 0);
+       regmap_write(info->regmap, LTC4162L_CHARGER_STATE_ALERTS_REG, 0);
+       regmap_write(info->regmap, LTC4162L_CHARGE_STATUS_ALERTS_REG, 0);
+}
+
+static int ltc4162l_probe(struct i2c_client *client,
+                       const struct i2c_device_id *id)
+{
+       struct i2c_adapter *adapter = client->adapter;
+       struct device *dev = &client->dev;
+       struct ltc4162l_info *info;
+       struct power_supply_config ltc4162l_config = {};
+       u32 value;
+       int ret;
+
+       if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_WORD_DATA)) {
+               dev_err(dev, "No support for SMBUS_WORD_DATA\n");
+               return -ENODEV;
+       }
+       info = devm_kzalloc(dev, sizeof(*info), GFP_KERNEL);
+       if (!info)
+               return -ENOMEM;
+
+       info->client = client;
+       i2c_set_clientdata(client, info);
+
+       info->regmap = devm_regmap_init_i2c(client, &ltc4162l_regmap_config);
+       if (IS_ERR(info->regmap)) {
+               dev_err(dev, "Failed to initialize register map\n");
+               return PTR_ERR(info->regmap);
+       }
+
+       ret = device_property_read_u32(dev, "lltc,rsnsb-micro-ohms",
+                                      &info->rsnsb);
+       if (ret) {
+               dev_err(dev, "Missing lltc,rsnsb-micro-ohms property\n");
+               return ret;
+       }
+       if (!info->rsnsb)
+               return -EINVAL;
+
+       ret = device_property_read_u32(dev, "lltc,rsnsi-micro-ohms",
+                                      &info->rsnsi);
+       if (ret) {
+               dev_err(dev, "Missing lltc,rsnsi-micro-ohms property\n");
+               return ret;
+       }
+       if (!info->rsnsi)
+               return -EINVAL;
+
+       if (!device_property_read_u32(dev, "lltc,cell-count", &value))
+               info->cell_count = value;
+
+       ltc4162l_config.of_node = dev->of_node;
+       ltc4162l_config.drv_data = info;
+       ltc4162l_config.attr_grp = ltc4162l_attr_groups;
+
+       info->charger = devm_power_supply_register(dev, &ltc4162l_desc,
+                                                  &ltc4162l_config);
+       if (IS_ERR(info->charger)) {
+               dev_err(dev, "Failed to register charger\n");
+               return PTR_ERR(info->charger);
+       }
+
+       /* Disable the threshold alerts, we're not using them */
+       regmap_write(info->regmap, LTC4162L_EN_LIMIT_ALERTS_REG, 0);
+
+       /* Enable interrupts on all status changes */
+       regmap_write(info->regmap, LTC4162L_EN_CHARGER_STATE_ALERTS_REG,
+                    0x1fff);
+       regmap_write(info->regmap, LTC4162L_EN_CHARGE_STATUS_ALERTS_REG, 0x1f);
+
+       ltc4162l_clear_interrupts(info);
+
+       return 0;
+}
+
+static void ltc4162l_alert(struct i2c_client *client,
+                          enum i2c_alert_protocol type, unsigned int flag)
+{
+       struct ltc4162l_info *info = i2c_get_clientdata(client);
+
+       if (type != I2C_PROTOCOL_SMBUS_ALERT)
+               return;
+
+       ltc4162l_clear_interrupts(info);
+       power_supply_changed(info->charger);
+}
+
+static const struct i2c_device_id ltc4162l_i2c_id_table[] = {
+       { "ltc4162-l", 0 },
+       { },
+};
+MODULE_DEVICE_TABLE(i2c, ltc4162l_i2c_id_table);
+
+static const struct of_device_id ltc4162l_of_match[] = {
+       { .compatible = "lltc,ltc4162-l", },
+       { },
+};
+MODULE_DEVICE_TABLE(of, ltc4162l_of_match);
+
+static struct i2c_driver ltc4162l_driver = {
+       .probe          = ltc4162l_probe,
+       .alert          = ltc4162l_alert,
+       .id_table       = ltc4162l_i2c_id_table,
+       .driver = {
+               .name           = "ltc4162-l-charger",
+               .of_match_table = of_match_ptr(ltc4162l_of_match),
+       },
+};
+module_i2c_driver(ltc4162l_driver);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Mike Looijmans <mike.looijmans@topic.nl>");
+MODULE_DESCRIPTION("LTC4162-L charger driver");