// SPDX-License-Identifier: GPL-2.0+ /* * Battery monitor driver for the uPI uG3105 battery monitor * * Note the uG3105 is not a full-featured autonomous fuel-gauge. Instead it is * expected to be use in combination with some always on microcontroller reading * its coulomb-counter before it can wrap (must be read every 400 seconds!). * * Since Linux does not monitor coulomb-counter changes while the device * is off or suspended, the coulomb counter is not used atm. * * Possible improvements: * 1. Activate commented out total_coulomb_count code * 2. Reset total_coulomb_count val to 0 when the battery is as good as empty * and remember that we did this (and clear the flag for this on susp/resume) * 3. When the battery is full check if the flag that we set total_coulomb_count * to when the battery was empty is set. If so we now know the capacity, * not the design, but actual capacity, of the battery * 4. Add some mechanism (needs userspace help, or maybe use efivar?) to remember * the actual capacity of the battery over reboots * 5. When we know the actual capacity at probe time, add energy_now and * energy_full attributes. Guess boot + resume energy_now value based on ocv * and then use total_coulomb_count to report energy_now over time, resetting * things to adjust for drift when empty/full. This should give more accurate * readings, esp. in the 30-70% range and allow userspace to estimate time * remaining till empty/full * 6. Maybe unregister + reregister the psy device when we learn the actual * capacity during run-time ? * * The above will also require some sort of mwh_per_unit calculation. Testing * has shown that an estimated 7404mWh increase of the battery's energy results * in a total_coulomb_count increase of 3277 units with a 5 milli-ohm sense R. * * Copyright (C) 2021 Hans de Goede <[email protected]> */ #include <linux/devm-helpers.h> #include <linux/module.h> #include <linux/mutex.h> #include <linux/slab.h> #include <linux/i2c.h> #include <linux/mod_devicetable.h> #include <linux/power_supply.h> #include <linux/workqueue.h> #define UG3105_MOV_AVG_WINDOW … #define UG3105_INIT_POLL_TIME … #define UG3105_POLL_TIME … #define UG3105_SETTLE_TIME … #define UG3105_INIT_POLL_COUNT … #define UG3105_REG_MODE … #define UG3105_REG_CTRL1 … #define UG3105_REG_COULOMB_CNT … #define UG3105_REG_BAT_VOLT … #define UG3105_REG_BAT_CURR … #define UG3105_MODE_STANDBY … #define UG3105_MODE_RUN … #define UG3105_CTRL1_RESET_COULOMB_CNT … #define UG3105_CURR_HYST_UA … #define UG3105_LOW_BAT_UV … #define UG3105_FULL_BAT_HYST_UV … struct ug3105_chip { … }; static int ug3105_read_word(struct i2c_client *client, u8 reg) { … } static int ug3105_get_status(struct ug3105_chip *chip) { … } static int ug3105_get_capacity(struct ug3105_chip *chip) { … } static void ug3105_work(struct work_struct *work) { … } static enum power_supply_property ug3105_battery_props[] = …; static int ug3105_get_property(struct power_supply *psy, enum power_supply_property psp, union power_supply_propval *val) { … } static void ug3105_external_power_changed(struct power_supply *psy) { … } static const struct power_supply_desc ug3105_psy_desc = …; static void ug3105_init(struct ug3105_chip *chip) { … } static int ug3105_probe(struct i2c_client *client) { … } static int __maybe_unused ug3105_suspend(struct device *dev) { … } static int __maybe_unused ug3105_resume(struct device *dev) { … } static SIMPLE_DEV_PM_OPS(ug3105_pm_ops, ug3105_suspend, ug3105_resume); static const struct i2c_device_id ug3105_id[] = …; MODULE_DEVICE_TABLE(i2c, ug3105_id); static struct i2c_driver ug3105_i2c_driver = …; module_i2c_driver(…) …; MODULE_AUTHOR(…) …; MODULE_DESCRIPTION(…) …; MODULE_LICENSE(…) …;
Codebase Browser
linux