--- /dev/null
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Fuel gauge driver for Maxim 17201/17205
+ *
+ * based on max1721x_battery.c
+ *
+ * Copyright (C) 2024 Liebherr-Electronics and Drives GmbH
+ */
+
+#include <linux/bitfield.h>
+#include <linux/i2c.h>
+#include <linux/module.h>
+#include <linux/power_supply.h>
+#include <linux/regmap.h>
+
+#include <asm/unaligned.h>
+
+/* Nonvolatile registers */
+#define MAX1720X_NRSENSE 0xCF /* RSense in 10^-5 Ohm */
+
+/* ModelGauge m5 */
+#define MAX172XX_STATUS 0x00 /* Status */
+#define MAX172XX_STATUS_BAT_ABSENT BIT(3) /* Battery absent */
+#define MAX172XX_REPCAP 0x05 /* Average capacity */
+#define MAX172XX_REPSOC 0x06 /* Percentage of charge */
+#define MAX172XX_TEMP 0x08 /* Temperature */
+#define MAX172XX_CURRENT 0x0A /* Actual current */
+#define MAX172XX_AVG_CURRENT 0x0B /* Average current */
+#define MAX172XX_TTE 0x11 /* Time to empty */
+#define MAX172XX_AVG_TA 0x16 /* Average temperature */
+#define MAX172XX_CYCLES 0x17
+#define MAX172XX_DESIGN_CAP 0x18 /* Design capacity */
+#define MAX172XX_AVG_VCELL 0x19
+#define MAX172XX_TTF 0x20 /* Time to full */
+#define MAX172XX_DEV_NAME 0x21 /* Device name */
+#define MAX172XX_DEV_NAME_TYPE_MASK GENMASK(3, 0)
+#define MAX172XX_DEV_NAME_TYPE_MAX17201 BIT(0)
+#define MAX172XX_DEV_NAME_TYPE_MAX17205 (BIT(0) | BIT(2))
+#define MAX172XX_QR_TABLE10 0x22
+#define MAX172XX_BATT 0xDA /* Battery voltage */
+#define MAX172XX_ATAVCAP 0xDF
+
+static const char *const max1720x_manufacturer = "Maxim Integrated";
+static const char *const max17201_model = "MAX17201";
+static const char *const max17205_model = "MAX17205";
+
+struct max1720x_device_info {
+ struct regmap *regmap;
+ int rsense;
+};
+
+/*
+ * Model Gauge M5 Algorithm output register
+ * Volatile data (must not be cached)
+ */
+static const struct regmap_range max1720x_volatile_allow[] = {
+ regmap_reg_range(MAX172XX_STATUS, MAX172XX_CYCLES),
+ regmap_reg_range(MAX172XX_AVG_VCELL, MAX172XX_TTF),
+ regmap_reg_range(MAX172XX_QR_TABLE10, MAX172XX_ATAVCAP),
+};
+
+static const struct regmap_range max1720x_readable_allow[] = {
+ regmap_reg_range(MAX172XX_STATUS, MAX172XX_ATAVCAP),
+};
+
+static const struct regmap_range max1720x_readable_deny[] = {
+ /* unused registers */
+ regmap_reg_range(0x24, 0x26),
+ regmap_reg_range(0x30, 0x31),
+ regmap_reg_range(0x33, 0x34),
+ regmap_reg_range(0x37, 0x37),
+ regmap_reg_range(0x3B, 0x3C),
+ regmap_reg_range(0x40, 0x41),
+ regmap_reg_range(0x43, 0x44),
+ regmap_reg_range(0x47, 0x49),
+ regmap_reg_range(0x4B, 0x4C),
+ regmap_reg_range(0x4E, 0xAF),
+ regmap_reg_range(0xB1, 0xB3),
+ regmap_reg_range(0xB5, 0xB7),
+ regmap_reg_range(0xBF, 0xD0),
+ regmap_reg_range(0xDB, 0xDB),
+ regmap_reg_range(0xE0, 0xFF),
+};
+
+static const struct regmap_access_table max1720x_readable_regs = {
+ .yes_ranges = max1720x_readable_allow,
+ .n_yes_ranges = ARRAY_SIZE(max1720x_readable_allow),
+ .no_ranges = max1720x_readable_deny,
+ .n_no_ranges = ARRAY_SIZE(max1720x_readable_deny),
+};
+
+static const struct regmap_access_table max1720x_volatile_regs = {
+ .yes_ranges = max1720x_volatile_allow,
+ .n_yes_ranges = ARRAY_SIZE(max1720x_volatile_allow),
+ .no_ranges = max1720x_readable_deny,
+ .n_no_ranges = ARRAY_SIZE(max1720x_readable_deny),
+};
+
+static const struct regmap_config max1720x_regmap_cfg = {
+ .reg_bits = 8,
+ .val_bits = 16,
+ .max_register = MAX172XX_ATAVCAP,
+ .val_format_endian = REGMAP_ENDIAN_LITTLE,
+ .rd_table = &max1720x_readable_regs,
+ .volatile_table = &max1720x_volatile_regs,
+ .cache_type = REGCACHE_RBTREE,
+};
+
+static const enum power_supply_property max1720x_battery_props[] = {
+ POWER_SUPPLY_PROP_PRESENT,
+ POWER_SUPPLY_PROP_CAPACITY,
+ POWER_SUPPLY_PROP_VOLTAGE_NOW,
+ POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN,
+ POWER_SUPPLY_PROP_CHARGE_AVG,
+ POWER_SUPPLY_PROP_TIME_TO_EMPTY_AVG,
+ POWER_SUPPLY_PROP_TIME_TO_FULL_AVG,
+ POWER_SUPPLY_PROP_TEMP,
+ POWER_SUPPLY_PROP_CURRENT_NOW,
+ POWER_SUPPLY_PROP_CURRENT_AVG,
+ POWER_SUPPLY_PROP_MODEL_NAME,
+ POWER_SUPPLY_PROP_MANUFACTURER,
+};
+
+/* Convert regs value to power_supply units */
+
+static int max172xx_time_to_ps(unsigned int reg)
+{
+ return reg * 5625 / 1000; /* in sec. */
+}
+
+static int max172xx_percent_to_ps(unsigned int reg)
+{
+ return reg / 256; /* in percent from 0 to 100 */
+}
+
+static int max172xx_voltage_to_ps(unsigned int reg)
+{
+ return reg * 1250; /* in uV */
+}
+
+static int max172xx_capacity_to_ps(unsigned int reg)
+{
+ return reg * 500; /* in uAh */
+}
+
+/*
+ * Current and temperature is signed values, so unsigned regs
+ * value must be converted to signed type
+ */
+
+static int max172xx_temperature_to_ps(unsigned int reg)
+{
+ int val = (int16_t)reg;
+
+ return val * 10 / 256; /* in tenths of deg. C */
+}
+
+/*
+ * Calculating current registers resolution:
+ *
+ * RSense stored in 10^-5 Ohm, so mesaurment voltage must be
+ * in 10^-11 Volts for get current in uA.
+ * 16 bit current reg fullscale +/-51.2mV is 102400 uV.
+ * So: 102400 / 65535 * 10^5 = 156252
+ */
+static int max172xx_current_to_voltage(unsigned int reg)
+{
+ int val = (int16_t)reg;
+
+ return val * 156252;
+}
+
+static int max1720x_battery_get_property(struct power_supply *psy,
+ enum power_supply_property psp,
+ union power_supply_propval *val)
+{
+ struct max1720x_device_info *info = power_supply_get_drvdata(psy);
+ unsigned int reg_val;
+ int ret = 0;
+
+ switch (psp) {
+ case POWER_SUPPLY_PROP_PRESENT:
+ /*
+ * POWER_SUPPLY_PROP_PRESENT will always readable via
+ * sysfs interface. Value return 0 if battery not
+ * present or unaccesable via I2c.
+ */
+ ret = regmap_read(info->regmap, MAX172XX_STATUS, ®_val);
+ if (ret < 0) {
+ val->intval = 0;
+ return 0;
+ }
+
+ val->intval = !FIELD_GET(MAX172XX_STATUS_BAT_ABSENT, reg_val);
+ break;
+ case POWER_SUPPLY_PROP_CAPACITY:
+ ret = regmap_read(info->regmap, MAX172XX_REPSOC, ®_val);
+ val->intval = max172xx_percent_to_ps(reg_val);
+ break;
+ case POWER_SUPPLY_PROP_VOLTAGE_NOW:
+ ret = regmap_read(info->regmap, MAX172XX_BATT, ®_val);
+ val->intval = max172xx_voltage_to_ps(reg_val);
+ break;
+ case POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN:
+ ret = regmap_read(info->regmap, MAX172XX_DESIGN_CAP, ®_val);
+ val->intval = max172xx_capacity_to_ps(reg_val);
+ break;
+ case POWER_SUPPLY_PROP_CHARGE_AVG:
+ ret = regmap_read(info->regmap, MAX172XX_REPCAP, ®_val);
+ val->intval = max172xx_capacity_to_ps(reg_val);
+ break;
+ case POWER_SUPPLY_PROP_TIME_TO_EMPTY_AVG:
+ ret = regmap_read(info->regmap, MAX172XX_TTE, ®_val);
+ val->intval = max172xx_time_to_ps(reg_val);
+ break;
+ case POWER_SUPPLY_PROP_TIME_TO_FULL_AVG:
+ ret = regmap_read(info->regmap, MAX172XX_TTF, ®_val);
+ val->intval = max172xx_time_to_ps(reg_val);
+ break;
+ case POWER_SUPPLY_PROP_TEMP:
+ ret = regmap_read(info->regmap, MAX172XX_TEMP, ®_val);
+ val->intval = max172xx_temperature_to_ps(reg_val);
+ break;
+ case POWER_SUPPLY_PROP_CURRENT_NOW:
+ ret = regmap_read(info->regmap, MAX172XX_CURRENT, ®_val);
+ val->intval = max172xx_current_to_voltage(reg_val) / info->rsense;
+ break;
+ case POWER_SUPPLY_PROP_CURRENT_AVG:
+ ret = regmap_read(info->regmap, MAX172XX_AVG_CURRENT, ®_val);
+ val->intval = max172xx_current_to_voltage(reg_val) / info->rsense;
+ break;
+ case POWER_SUPPLY_PROP_MODEL_NAME:
+ ret = regmap_read(info->regmap, MAX172XX_DEV_NAME, ®_val);
+ reg_val = FIELD_GET(MAX172XX_DEV_NAME_TYPE_MASK, reg_val);
+ if (reg_val == MAX172XX_DEV_NAME_TYPE_MAX17201)
+ val->strval = max17201_model;
+ else if (reg_val == MAX172XX_DEV_NAME_TYPE_MAX17205)
+ val->strval = max17205_model;
+ else
+ return -ENODEV;
+ break;
+ case POWER_SUPPLY_PROP_MANUFACTURER:
+ val->strval = max1720x_manufacturer;
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ return ret;
+}
+
+static int max1720x_probe_sense_resistor(struct i2c_client *client,
+ struct max1720x_device_info *info)
+{
+ struct device *dev = &client->dev;
+ struct i2c_client *ancillary;
+ int ret;
+
+ ancillary = i2c_new_ancillary_device(client, "nvmem", 0xb);
+ if (IS_ERR(ancillary)) {
+ dev_err(dev, "Failed to initialize ancillary i2c device\n");
+ return PTR_ERR(ancillary);
+ }
+
+ ret = i2c_smbus_read_word_data(ancillary, MAX1720X_NRSENSE);
+ i2c_unregister_device(ancillary);
+ if (ret < 0)
+ return ret;
+
+ info->rsense = ret;
+ if (!info->rsense) {
+ dev_warn(dev, "RSense not calibrated, set 10 mOhms!\n");
+ info->rsense = 1000; /* in regs in 10^-5 */
+ }
+
+ return 0;
+}
+
+static const struct power_supply_desc max1720x_bat_desc = {
+ .name = "max1720x",
+ .no_thermal = true,
+ .type = POWER_SUPPLY_TYPE_BATTERY,
+ .properties = max1720x_battery_props,
+ .num_properties = ARRAY_SIZE(max1720x_battery_props),
+ .get_property = max1720x_battery_get_property,
+};
+
+static int max1720x_probe(struct i2c_client *client)
+{
+ struct power_supply_config psy_cfg = {};
+ struct device *dev = &client->dev;
+ struct max1720x_device_info *info;
+ struct power_supply *bat;
+ int ret;
+
+ info = devm_kzalloc(dev, sizeof(*info), GFP_KERNEL);
+ if (!info)
+ return -ENOMEM;
+
+ psy_cfg.drv_data = info;
+ psy_cfg.fwnode = dev_fwnode(dev);
+ info->regmap = devm_regmap_init_i2c(client, &max1720x_regmap_cfg);
+ if (IS_ERR(info->regmap))
+ return dev_err_probe(dev, PTR_ERR(info->regmap),
+ "regmap initialization failed\n");
+
+ ret = max1720x_probe_sense_resistor(client, info);
+ if (ret)
+ return dev_err_probe(dev, ret,
+ "Failed to read sense resistor value\n");
+
+ bat = devm_power_supply_register(dev, &max1720x_bat_desc, &psy_cfg);
+ if (IS_ERR(bat))
+ return dev_err_probe(dev, PTR_ERR(bat),
+ "Failed to register power supply\n");
+
+ return 0;
+}
+
+static const struct of_device_id max1720x_of_match[] = {
+ { .compatible = "maxim,max17201" },
+ {}
+};
+MODULE_DEVICE_TABLE(of, max1720x_of_match);
+
+static struct i2c_driver max1720x_i2c_driver = {
+ .driver = {
+ .name = "max1720x",
+ .of_match_table = max1720x_of_match,
+ },
+ .probe = max1720x_probe,
+};
+module_i2c_driver(max1720x_i2c_driver);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Dimitri Fedrau <dima.fedrau@gmail.com>");
+MODULE_DESCRIPTION("Maxim MAX17201/MAX17205 Fuel Gauge IC driver");
projects / thirdparty / linux.git / commitdiff
