| Message ID | 20220131155730.309513-9-hdegoede@redhat.com |
|---|---|
| State | Superseded |
| Headers | show |
| Series | power: supply: bq24190 updates + new ug3105 driver | expand |
Hi, On Mon, Jan 31, 2022 at 04:57:30PM +0100, Hans de Goede wrote: > Add a new battery 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. > > So far this driver is only used on x86/ACPI (non devicetree) devs > (also note there is no of_match table). Therefor there is no devicetree > bindings documentation for this driver's "upi,rsns-microohm" property > since this is not used in actual devicetree files and the dt bindings > maintainers have requested properties with no actual dt users to > _not_ be added to the dt bindings. > > The property's name has been chosen so that it should not need to be > changed if/when devicetree enumeration support gets added later, as it > mirrors "maxim,rsns-microohm" from the "maxim,max17042" bindings. Except the vendor prefix being incorrect; please use this one: $ grep -i upi Documentation/devicetree/bindings/vendor-prefixes.yaml "^upisemi,.*": description: uPI Semiconductor Corp. > Signed-off-by: Hans de Goede <hdegoede@redhat.com> > --- > drivers/power/supply/Kconfig | 15 + > drivers/power/supply/Makefile | 1 + > drivers/power/supply/ug3105_battery.c | 486 ++++++++++++++++++++++++++ > 3 files changed, 502 insertions(+) > create mode 100644 drivers/power/supply/ug3105_battery.c > > diff --git a/drivers/power/supply/Kconfig b/drivers/power/supply/Kconfig > index b366e2fd8e97..6b15eb184072 100644 > --- a/drivers/power/supply/Kconfig > +++ b/drivers/power/supply/Kconfig > @@ -866,4 +866,19 @@ config CHARGER_SURFACE > Microsoft Surface devices, i.e. Surface Pro 7, Surface Laptop 3, > Surface Book 3, and Surface Laptop Go. > > +config BATTERY_UG3105 > + tristate "uPI uG3105 battery monitor driver" > + depends on I2C > + help > + 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 > + (it must be read every 400 seconds!). > + > + Since Linux does not monitor coulomb-counter changes while the > + device is off or suspended, the functionality of this driver is > + limited to reporting capacity only. > + > endif # POWER_SUPPLY > diff --git a/drivers/power/supply/Makefile b/drivers/power/supply/Makefile > index 2c1b264b2046..edf983676799 100644 > --- a/drivers/power/supply/Makefile > +++ b/drivers/power/supply/Makefile > @@ -105,3 +105,4 @@ obj-$(CONFIG_RN5T618_POWER) += rn5t618_power.o > obj-$(CONFIG_BATTERY_ACER_A500) += acer_a500_battery.o > obj-$(CONFIG_BATTERY_SURFACE) += surface_battery.o > obj-$(CONFIG_CHARGER_SURFACE) += surface_charger.o > +obj-$(CONFIG_BATTERY_UG3105) += ug3105_battery.o > diff --git a/drivers/power/supply/ug3105_battery.c b/drivers/power/supply/ug3105_battery.c > new file mode 100644 > index 000000000000..d92a7ebeb26e > --- /dev/null > +++ b/drivers/power/supply/ug3105_battery.c > @@ -0,0 +1,486 @@ > +// 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 ? Same problem also exists on a few mobile phones, e.g. drivers/power/supply/cpcap-battery.c, but no good solution has been found yet. > + * 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 <hdegoede@redhat.com> > + */ > + > +#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 8 > +#define UG3105_INIT_POLL_TIME (5 * HZ) > +#define UG3105_POLL_TIME (30 * HZ) > +#define UG3105_SETTLE_TIME (1 * HZ) > + > +#define UG3105_INIT_POLL_COUNT 30 > + > +#define UG3105_REG_MODE 0x00 > +#define UG3105_REG_CTRL1 0x01 > +#define UG3105_REG_COULOMB_CNT 0x02 > +#define UG3105_REG_BAT_VOLT 0x08 > +#define UG3105_REG_BAT_CURR 0x0c > + > +#define UG3105_MODE_STANDBY 0x00 > +#define UG3105_MODE_RUN 0x10 > + > +#define UG3105_CTRL1_RESET_COULOMB_CNT 0x03 > + > +#define UG3105_CURR_HYST_UA 65000 > + > +#define UG3105_LOW_BAT_UV 3700000 > +#define UG3105_FULL_BAT_HYST_UV 38000 > + > +struct ug3105_chip { > + struct i2c_client *client; > + struct power_supply *psy; > + struct power_supply_battery_info *info; > + struct delayed_work work; > + struct mutex lock; > + int ocv[UG3105_MOV_AVG_WINDOW]; /* micro-volt */ > + int intern_res[UG3105_MOV_AVG_WINDOW]; /* milli-ohm */ > + int poll_count; > + int ocv_avg_index; > + int ocv_avg; /* micro-volt */ > + int intern_res_poll_count; > + int intern_res_avg_index; > + int intern_res_avg; /* milli-ohm */ > + int volt; /* micro-volt */ > + int curr; /* micro-ampere */ > + int total_coulomb_count; > + int uv_per_unit; > + int ua_per_unit; > + int status; > + int capacity; > + bool supplied; > +}; > + > +static int ug3105_read_word(struct i2c_client *client, u8 reg) > +{ > + int val; > + > + val = i2c_smbus_read_word_data(client, reg); > + if (val < 0) > + dev_err(&client->dev, "Error reading reg 0x%02x\n", reg); > + > + return val; > +} can we use regmap instead? :) > +static int ug3105_get_status(struct ug3105_chip *chip) > +{ > + int full = chip->info->constant_charge_voltage_max_uv - UG3105_FULL_BAT_HYST_UV; > + > + if (chip->curr > UG3105_CURR_HYST_UA) > + return POWER_SUPPLY_STATUS_CHARGING; > + > + if (chip->curr < -UG3105_CURR_HYST_UA) > + return POWER_SUPPLY_STATUS_DISCHARGING; > + > + if (chip->supplied && chip->ocv_avg > full) > + return POWER_SUPPLY_STATUS_FULL; > + > + return POWER_SUPPLY_STATUS_NOT_CHARGING; > +} > + > +static int ug3105_get_capacity(struct ug3105_chip *chip) > +{ > + /* > + * OCV voltages in uV for 0-110% in 5% increments, the 100-110% is > + * for LiPo HV (High-Voltage) bateries which can go up to 4.35V > + * instead of the usual 4.2V. > + */ > + static const int ocv_capacity_tbl[23] = { > + 3350000, > + 3610000, > + 3690000, > + 3710000, > + 3730000, > + 3750000, > + 3770000, > + 3786667, > + 3803333, > + 3820000, > + 3836667, > + 3853333, > + 3870000, > + 3907500, > + 3945000, > + 3982500, > + 4020000, > + 4075000, > + 4110000, > + 4150000, > + 4200000, > + 4250000, > + 4300000, > + }; > + int i, ocv_diff, ocv_step; > + > + if (chip->ocv_avg < ocv_capacity_tbl[0]) > + return 0; > + > + if (chip->status == POWER_SUPPLY_STATUS_FULL) > + return 100; > + > + for (i = 1; i < ARRAY_SIZE(ocv_capacity_tbl); i++) { > + if (chip->ocv_avg > ocv_capacity_tbl[i]) > + continue; > + > + ocv_diff = ocv_capacity_tbl[i] - chip->ocv_avg; > + ocv_step = ocv_capacity_tbl[i] - ocv_capacity_tbl[i - 1]; > + /* scale 0-110% down to 0-100% for LiPo HV */ > + if (chip->info->constant_charge_voltage_max_uv >= 4300000) > + return (i * 500 - ocv_diff * 500 / ocv_step) / 110; > + else > + return i * 5 - ocv_diff * 5 / ocv_step; > + } > + > + return 100; > +} > + > +static void ug3105_work(struct work_struct *work) > +{ > + struct ug3105_chip *chip = container_of(work, struct ug3105_chip, > + work.work); > + int i, val, curr_diff, volt_diff, res, win_size; > + bool prev_supplied = chip->supplied; > + int prev_status = chip->status; > + int prev_volt = chip->volt; > + int prev_curr = chip->curr; > + struct power_supply *psy; > + > + mutex_lock(&chip->lock); > + > + psy = chip->psy; > + if (!psy) > + goto out; > + > + val = ug3105_read_word(chip->client, UG3105_REG_BAT_VOLT); > + if (val < 0) > + goto out; > + chip->volt = val * chip->uv_per_unit; > + > + val = ug3105_read_word(chip->client, UG3105_REG_BAT_CURR); > + if (val < 0) > + goto out; > + chip->curr = (s16)val * chip->ua_per_unit; > + > + chip->ocv[chip->ocv_avg_index] = > + chip->volt - chip->curr * chip->intern_res_avg / 1000; > + chip->ocv_avg_index = (chip->ocv_avg_index + 1) % UG3105_MOV_AVG_WINDOW; > + chip->poll_count++; > + > + /* > + * See possible improvements comment above. > + * > + * Read + reset coulomb counter every 10 polls (every 300 seconds) > + * if ((chip->poll_count % 10) == 0) { > + * val = ug3105_read_word(chip->client, UG3105_REG_COULOMB_CNT); > + * if (val < 0) > + * goto out; > + * > + * i2c_smbus_write_byte_data(chip->client, UG3105_REG_CTRL1, > + * UG3105_CTRL1_RESET_COULOMB_CNT); > + * > + * chip->total_coulomb_count += (s16)val; > + * dev_dbg(&chip->client->dev, "coulomb count %d total %d\n", > + * (s16)val, chip->total_coulomb_count); > + * } > + */ > + > + chip->ocv_avg = 0; > + win_size = min(chip->poll_count, UG3105_MOV_AVG_WINDOW); > + for (i = 0; i < win_size; i++) > + chip->ocv_avg += chip->ocv[i]; > + chip->ocv_avg /= win_size; > + > + chip->supplied = power_supply_am_i_supplied(psy); > + chip->status = ug3105_get_status(chip); > + chip->capacity = ug3105_get_capacity(chip); > + > + /* > + * Skip internal resistance calc on charger [un]plug and > + * when the battery is almost empty (voltage low). > + */ > + if (chip->supplied != prev_supplied || > + chip->volt < UG3105_LOW_BAT_UV || > + chip->poll_count < 2) > + goto out; > + > + /* > + * Assuming that the OCV voltage does not change significantly > + * between 2 polls, then we can calculate the internal resistance > + * on a significant current change by attributing all voltage > + * change between the 2 readings to the internal resistance. > + */ > + curr_diff = abs(chip->curr - prev_curr); > + if (curr_diff < UG3105_CURR_HYST_UA) > + goto out; > + > + volt_diff = abs(chip->volt - prev_volt); > + res = volt_diff * 1000 / curr_diff; > + > + if ((res < (chip->intern_res_avg * 2 / 3)) || > + (res > (chip->intern_res_avg * 4 / 3))) { > + dev_dbg(&chip->client->dev, "Ignoring outlier internal resistance %d mOhm\n", res); > + goto out; > + } > + > + dev_dbg(&chip->client->dev, "Internal resistance %d mOhm\n", res); > + > + chip->intern_res[chip->intern_res_avg_index] = res; > + chip->intern_res_avg_index = (chip->intern_res_avg_index + 1) % UG3105_MOV_AVG_WINDOW; > + chip->intern_res_poll_count++; > + > + chip->intern_res_avg = 0; > + win_size = min(chip->intern_res_poll_count, UG3105_MOV_AVG_WINDOW); > + for (i = 0; i < win_size; i++) > + chip->intern_res_avg += chip->intern_res[i]; > + chip->intern_res_avg /= win_size; > + > +out: > + mutex_unlock(&chip->lock); > + > + queue_delayed_work(system_wq, &chip->work, > + (chip->poll_count <= UG3105_INIT_POLL_COUNT) ? > + UG3105_INIT_POLL_TIME : UG3105_POLL_TIME); > + > + if (chip->status != prev_status && psy) > + power_supply_changed(psy); > +} > + > +static enum power_supply_property ug3105_battery_props[] = { > + POWER_SUPPLY_PROP_STATUS, > + POWER_SUPPLY_PROP_PRESENT, > + POWER_SUPPLY_PROP_TECHNOLOGY, > + POWER_SUPPLY_PROP_SCOPE, > + POWER_SUPPLY_PROP_VOLTAGE_NOW, > + POWER_SUPPLY_PROP_VOLTAGE_OCV, > + POWER_SUPPLY_PROP_CURRENT_NOW, > + POWER_SUPPLY_PROP_CAPACITY, > +}; > + > +static int ug3105_get_property(struct power_supply *psy, > + enum power_supply_property psp, > + union power_supply_propval *val) > +{ > + struct ug3105_chip *chip = power_supply_get_drvdata(psy); > + int ret = 0; > + > + mutex_lock(&chip->lock); > + > + if (!chip->psy) { > + ret = -EAGAIN; > + goto out; > + } > + > + switch (psp) { > + case POWER_SUPPLY_PROP_STATUS: > + val->intval = chip->status; > + break; > + case POWER_SUPPLY_PROP_PRESENT: > + val->intval = 1; > + break; > + case POWER_SUPPLY_PROP_TECHNOLOGY: > + val->intval = chip->info->technology; > + break; > + case POWER_SUPPLY_PROP_SCOPE: > + val->intval = POWER_SUPPLY_SCOPE_SYSTEM; > + break; > + case POWER_SUPPLY_PROP_VOLTAGE_NOW: > + ret = ug3105_read_word(chip->client, UG3105_REG_BAT_VOLT); > + if (ret < 0) > + break; > + val->intval = ret * chip->uv_per_unit; > + ret = 0; > + break; > + case POWER_SUPPLY_PROP_VOLTAGE_OCV: > + val->intval = chip->ocv_avg; > + break; > + case POWER_SUPPLY_PROP_CURRENT_NOW: > + ret = ug3105_read_word(chip->client, UG3105_REG_BAT_CURR); > + if (ret < 0) > + break; > + val->intval = (s16)ret * chip->ua_per_unit; > + ret = 0; > + break; > + case POWER_SUPPLY_PROP_CAPACITY: > + val->intval = chip->capacity; > + break; > + default: > + ret = -EINVAL; > + } > + > +out: > + mutex_unlock(&chip->lock); > + return ret; > +} > + > +static void ug3105_external_power_changed(struct power_supply *psy) > +{ > + struct ug3105_chip *chip = power_supply_get_drvdata(psy); > + > + dev_dbg(&chip->client->dev, "external power changed\n"); > + mod_delayed_work(system_wq, &chip->work, UG3105_SETTLE_TIME); > +} > + > +static const struct power_supply_desc ug3105_psy_desc = { > + .name = "ug3105_battery", > + .type = POWER_SUPPLY_TYPE_BATTERY, > + .get_property = ug3105_get_property, > + .external_power_changed = ug3105_external_power_changed, > + .properties = ug3105_battery_props, > + .num_properties = ARRAY_SIZE(ug3105_battery_props), > +}; > + > +static void ug3105_init(struct ug3105_chip *chip) > +{ > + chip->poll_count = 0; > + chip->ocv_avg_index = 0; > + chip->total_coulomb_count = 0; > + i2c_smbus_write_byte_data(chip->client, UG3105_REG_MODE, > + UG3105_MODE_RUN); > + i2c_smbus_write_byte_data(chip->client, UG3105_REG_CTRL1, > + UG3105_CTRL1_RESET_COULOMB_CNT); > + queue_delayed_work(system_wq, &chip->work, 0); > + flush_delayed_work(&chip->work); > +} > + > +static int ug3105_probe(struct i2c_client *client) > +{ > + struct power_supply_config psy_cfg = {}; > + struct device *dev = &client->dev; > + u32 curr_sense_res_uohm = 10000; > + struct power_supply *psy; > + struct ug3105_chip *chip; > + int ret; > + > + chip = devm_kzalloc(dev, sizeof(*chip), GFP_KERNEL); > + if (!chip) > + return -ENOMEM; > + > + chip->client = client; > + mutex_init(&chip->lock); > + ret = devm_delayed_work_autocancel(dev, &chip->work, ug3105_work); > + if (ret) > + return ret; > + > + psy_cfg.drv_data = chip; > + psy = devm_power_supply_register(dev, &ug3105_psy_desc, &psy_cfg); > + if (IS_ERR(psy)) > + return PTR_ERR(psy); > + > + ret = power_supply_get_battery_info(psy, &chip->info); > + if (ret) > + return ret; this allocates data, so you need to call power_supply_put_battery_info() when chip->info is no loner required. > + > + if (chip->info->factory_internal_resistance_uohm == -EINVAL || > + chip->info->constant_charge_voltage_max_uv == -EINVAL) { > + dev_err(dev, "error required properties are missing\n"); > + return -ENODEV; > + } > + > + device_property_read_u32(dev, "upi,rsns-microohm", &curr_sense_res_uohm); > + > + /* > + * DAC maximum is 4.5V divided by 65536 steps + an unknown factor of 10 > + * coming from somewhere for some reason (verified with a volt-meter). > + */ > + chip->uv_per_unit = 45000000/65536; > + /* Datasheet says 8.1 uV per unit for the current ADC */ > + chip->ua_per_unit = 8100000 / curr_sense_res_uohm; > + > + /* Use provided internal resistance as start point (in milli-ohm) */ > + chip->intern_res_avg = chip->info->factory_internal_resistance_uohm / 1000; > + /* Also add it to the internal resistance moving average window */ > + chip->intern_res[0] = chip->intern_res_avg; > + chip->intern_res_avg_index = 1; > + chip->intern_res_poll_count = 1; > + > + mutex_lock(&chip->lock); > + chip->psy = psy; > + mutex_unlock(&chip->lock); > + > + ug3105_init(chip); > + > + i2c_set_clientdata(client, chip); > + return 0; > +} > + > +static int __maybe_unused ug3105_suspend(struct device *dev) > +{ > + struct ug3105_chip *chip = dev_get_drvdata(dev); > + > + cancel_delayed_work_sync(&chip->work); > + i2c_smbus_write_byte_data(chip->client, UG3105_REG_MODE, > + UG3105_MODE_STANDBY); > + > + return 0; > +} > + > +static int __maybe_unused ug3105_resume(struct device *dev) > +{ > + struct ug3105_chip *chip = dev_get_drvdata(dev); > + > + ug3105_init(chip); > + > + return 0; > +} > + > +static SIMPLE_DEV_PM_OPS(ug3105_pm_ops, ug3105_suspend, > + ug3105_resume); > + > +static const struct i2c_device_id ug3105_id[] = { > + { "ug3105" }, > + { } > +}; > +MODULE_DEVICE_TABLE(i2c, ug3105_id); > + > +static struct i2c_driver ug3105_i2c_driver = { > + .driver = { > + .name = "ug3105", > + .pm = &ug3105_pm_ops, > + }, > + .probe_new = ug3105_probe, > + .id_table = ug3105_id, > +}; > +module_i2c_driver(ug3105_i2c_driver); > + > +MODULE_AUTHOR("Hans de Goede <hdegoede@redhat.com"); > +MODULE_DESCRIPTION("uPI uG3105 battery monitor driver"); > +MODULE_LICENSE("GPL"); Otherwise LGTM. -- Sebastian
Hi Sebastian, Thank you for the review and thank you for merging the axp288-fuel-gauge and the bug bq25890 series. On 2/2/22 00:33, Sebastian Reichel wrote: > Hi, > > On Mon, Jan 31, 2022 at 04:57:30PM +0100, Hans de Goede wrote: >> Add a new battery 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. >> >> So far this driver is only used on x86/ACPI (non devicetree) devs >> (also note there is no of_match table). Therefor there is no devicetree >> bindings documentation for this driver's "upi,rsns-microohm" property >> since this is not used in actual devicetree files and the dt bindings >> maintainers have requested properties with no actual dt users to >> _not_ be added to the dt bindings. >> >> The property's name has been chosen so that it should not need to be >> changed if/when devicetree enumeration support gets added later, as it >> mirrors "maxim,rsns-microohm" from the "maxim,max17042" bindings. > > Except the vendor prefix being incorrect; please use this one: > > $ grep -i upi Documentation/devicetree/bindings/vendor-prefixes.yaml > "^upisemi,.*": > description: uPI Semiconductor Corp. Ah I didn't realize there already was a vendor prefix for uPI, will fix for v2. <snip> > +static int ug3105_read_word(struct i2c_client *client, u8 reg) >> +{ >> + int val; >> + >> + val = i2c_smbus_read_word_data(client, reg); >> + if (val < 0) >> + dev_err(&client->dev, "Error reading reg 0x%02x\n", reg); >> + >> + return val; >> +} > > can we use regmap instead? :) That would be tricky, since some registers are 8 bit, where as others are 16 bit. Where as the i2c-regmap code assumes a fixed register-size. Also I don't really see much added value for this driver to use the regmap abstraction, so I believe it would be better to just keep this as is and I'm going to keep this as is for v2. <snip> >> +static int ug3105_probe(struct i2c_client *client) >> +{ >> + struct power_supply_config psy_cfg = {}; >> + struct device *dev = &client->dev; >> + u32 curr_sense_res_uohm = 10000; >> + struct power_supply *psy; >> + struct ug3105_chip *chip; >> + int ret; >> + >> + chip = devm_kzalloc(dev, sizeof(*chip), GFP_KERNEL); >> + if (!chip) >> + return -ENOMEM; >> + >> + chip->client = client; >> + mutex_init(&chip->lock); >> + ret = devm_delayed_work_autocancel(dev, &chip->work, ug3105_work); >> + if (ret) >> + return ret; >> + >> + psy_cfg.drv_data = chip; >> + psy = devm_power_supply_register(dev, &ug3105_psy_desc, &psy_cfg); >> + if (IS_ERR(psy)) >> + return PTR_ERR(psy); >> + >> + ret = power_supply_get_battery_info(psy, &chip->info); >> + if (ret) >> + return ret; > > this allocates data, so you need to call power_supply_put_battery_info() > when chip->info is no loner required. ug3105_work() and ug3105_get_property() both use the info, so it is needed until the driver gets unbound; and since the memory allocated by power_supply_get_battery_info() is allocated using devm_kmalloc it will get freed on driver-unbind automatically. So AFAICT there is no need to call power_supply_put_battery_info() (which uses devm_kfree() internally to avoid the memory being free-ed a second time on driver unbind). Regards, Hans
diff --git a/drivers/power/supply/Kconfig b/drivers/power/supply/Kconfig index b366e2fd8e97..6b15eb184072 100644 --- a/drivers/power/supply/Kconfig +++ b/drivers/power/supply/Kconfig @@ -866,4 +866,19 @@ config CHARGER_SURFACE Microsoft Surface devices, i.e. Surface Pro 7, Surface Laptop 3, Surface Book 3, and Surface Laptop Go. +config BATTERY_UG3105 + tristate "uPI uG3105 battery monitor driver" + depends on I2C + help + 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 + (it must be read every 400 seconds!). + + Since Linux does not monitor coulomb-counter changes while the + device is off or suspended, the functionality of this driver is + limited to reporting capacity only. + endif # POWER_SUPPLY diff --git a/drivers/power/supply/Makefile b/drivers/power/supply/Makefile index 2c1b264b2046..edf983676799 100644 --- a/drivers/power/supply/Makefile +++ b/drivers/power/supply/Makefile @@ -105,3 +105,4 @@ obj-$(CONFIG_RN5T618_POWER) += rn5t618_power.o obj-$(CONFIG_BATTERY_ACER_A500) += acer_a500_battery.o obj-$(CONFIG_BATTERY_SURFACE) += surface_battery.o obj-$(CONFIG_CHARGER_SURFACE) += surface_charger.o +obj-$(CONFIG_BATTERY_UG3105) += ug3105_battery.o diff --git a/drivers/power/supply/ug3105_battery.c b/drivers/power/supply/ug3105_battery.c new file mode 100644 index 000000000000..d92a7ebeb26e --- /dev/null +++ b/drivers/power/supply/ug3105_battery.c @@ -0,0 +1,486 @@ +// 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 <hdegoede@redhat.com> + */ + +#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 8 +#define UG3105_INIT_POLL_TIME (5 * HZ) +#define UG3105_POLL_TIME (30 * HZ) +#define UG3105_SETTLE_TIME (1 * HZ) + +#define UG3105_INIT_POLL_COUNT 30 + +#define UG3105_REG_MODE 0x00 +#define UG3105_REG_CTRL1 0x01 +#define UG3105_REG_COULOMB_CNT 0x02 +#define UG3105_REG_BAT_VOLT 0x08 +#define UG3105_REG_BAT_CURR 0x0c + +#define UG3105_MODE_STANDBY 0x00 +#define UG3105_MODE_RUN 0x10 + +#define UG3105_CTRL1_RESET_COULOMB_CNT 0x03 + +#define UG3105_CURR_HYST_UA 65000 + +#define UG3105_LOW_BAT_UV 3700000 +#define UG3105_FULL_BAT_HYST_UV 38000 + +struct ug3105_chip { + struct i2c_client *client; + struct power_supply *psy; + struct power_supply_battery_info *info; + struct delayed_work work; + struct mutex lock; + int ocv[UG3105_MOV_AVG_WINDOW]; /* micro-volt */ + int intern_res[UG3105_MOV_AVG_WINDOW]; /* milli-ohm */ + int poll_count; + int ocv_avg_index; + int ocv_avg; /* micro-volt */ + int intern_res_poll_count; + int intern_res_avg_index; + int intern_res_avg; /* milli-ohm */ + int volt; /* micro-volt */ + int curr; /* micro-ampere */ + int total_coulomb_count; + int uv_per_unit; + int ua_per_unit; + int status; + int capacity; + bool supplied; +}; + +static int ug3105_read_word(struct i2c_client *client, u8 reg) +{ + int val; + + val = i2c_smbus_read_word_data(client, reg); + if (val < 0) + dev_err(&client->dev, "Error reading reg 0x%02x\n", reg); + + return val; +} + +static int ug3105_get_status(struct ug3105_chip *chip) +{ + int full = chip->info->constant_charge_voltage_max_uv - UG3105_FULL_BAT_HYST_UV; + + if (chip->curr > UG3105_CURR_HYST_UA) + return POWER_SUPPLY_STATUS_CHARGING; + + if (chip->curr < -UG3105_CURR_HYST_UA) + return POWER_SUPPLY_STATUS_DISCHARGING; + + if (chip->supplied && chip->ocv_avg > full) + return POWER_SUPPLY_STATUS_FULL; + + return POWER_SUPPLY_STATUS_NOT_CHARGING; +} + +static int ug3105_get_capacity(struct ug3105_chip *chip) +{ + /* + * OCV voltages in uV for 0-110% in 5% increments, the 100-110% is + * for LiPo HV (High-Voltage) bateries which can go up to 4.35V + * instead of the usual 4.2V. + */ + static const int ocv_capacity_tbl[23] = { + 3350000, + 3610000, + 3690000, + 3710000, + 3730000, + 3750000, + 3770000, + 3786667, + 3803333, + 3820000, + 3836667, + 3853333, + 3870000, + 3907500, + 3945000, + 3982500, + 4020000, + 4075000, + 4110000, + 4150000, + 4200000, + 4250000, + 4300000, + }; + int i, ocv_diff, ocv_step; + + if (chip->ocv_avg < ocv_capacity_tbl[0]) + return 0; + + if (chip->status == POWER_SUPPLY_STATUS_FULL) + return 100; + + for (i = 1; i < ARRAY_SIZE(ocv_capacity_tbl); i++) { + if (chip->ocv_avg > ocv_capacity_tbl[i]) + continue; + + ocv_diff = ocv_capacity_tbl[i] - chip->ocv_avg; + ocv_step = ocv_capacity_tbl[i] - ocv_capacity_tbl[i - 1]; + /* scale 0-110% down to 0-100% for LiPo HV */ + if (chip->info->constant_charge_voltage_max_uv >= 4300000) + return (i * 500 - ocv_diff * 500 / ocv_step) / 110; + else + return i * 5 - ocv_diff * 5 / ocv_step; + } + + return 100; +} + +static void ug3105_work(struct work_struct *work) +{ + struct ug3105_chip *chip = container_of(work, struct ug3105_chip, + work.work); + int i, val, curr_diff, volt_diff, res, win_size; + bool prev_supplied = chip->supplied; + int prev_status = chip->status; + int prev_volt = chip->volt; + int prev_curr = chip->curr; + struct power_supply *psy; + + mutex_lock(&chip->lock); + + psy = chip->psy; + if (!psy) + goto out; + + val = ug3105_read_word(chip->client, UG3105_REG_BAT_VOLT); + if (val < 0) + goto out; + chip->volt = val * chip->uv_per_unit; + + val = ug3105_read_word(chip->client, UG3105_REG_BAT_CURR); + if (val < 0) + goto out; + chip->curr = (s16)val * chip->ua_per_unit; + + chip->ocv[chip->ocv_avg_index] = + chip->volt - chip->curr * chip->intern_res_avg / 1000; + chip->ocv_avg_index = (chip->ocv_avg_index + 1) % UG3105_MOV_AVG_WINDOW; + chip->poll_count++; + + /* + * See possible improvements comment above. + * + * Read + reset coulomb counter every 10 polls (every 300 seconds) + * if ((chip->poll_count % 10) == 0) { + * val = ug3105_read_word(chip->client, UG3105_REG_COULOMB_CNT); + * if (val < 0) + * goto out; + * + * i2c_smbus_write_byte_data(chip->client, UG3105_REG_CTRL1, + * UG3105_CTRL1_RESET_COULOMB_CNT); + * + * chip->total_coulomb_count += (s16)val; + * dev_dbg(&chip->client->dev, "coulomb count %d total %d\n", + * (s16)val, chip->total_coulomb_count); + * } + */ + + chip->ocv_avg = 0; + win_size = min(chip->poll_count, UG3105_MOV_AVG_WINDOW); + for (i = 0; i < win_size; i++) + chip->ocv_avg += chip->ocv[i]; + chip->ocv_avg /= win_size; + + chip->supplied = power_supply_am_i_supplied(psy); + chip->status = ug3105_get_status(chip); + chip->capacity = ug3105_get_capacity(chip); + + /* + * Skip internal resistance calc on charger [un]plug and + * when the battery is almost empty (voltage low). + */ + if (chip->supplied != prev_supplied || + chip->volt < UG3105_LOW_BAT_UV || + chip->poll_count < 2) + goto out; + + /* + * Assuming that the OCV voltage does not change significantly + * between 2 polls, then we can calculate the internal resistance + * on a significant current change by attributing all voltage + * change between the 2 readings to the internal resistance. + */ + curr_diff = abs(chip->curr - prev_curr); + if (curr_diff < UG3105_CURR_HYST_UA) + goto out; + + volt_diff = abs(chip->volt - prev_volt); + res = volt_diff * 1000 / curr_diff; + + if ((res < (chip->intern_res_avg * 2 / 3)) || + (res > (chip->intern_res_avg * 4 / 3))) { + dev_dbg(&chip->client->dev, "Ignoring outlier internal resistance %d mOhm\n", res); + goto out; + } + + dev_dbg(&chip->client->dev, "Internal resistance %d mOhm\n", res); + + chip->intern_res[chip->intern_res_avg_index] = res; + chip->intern_res_avg_index = (chip->intern_res_avg_index + 1) % UG3105_MOV_AVG_WINDOW; + chip->intern_res_poll_count++; + + chip->intern_res_avg = 0; + win_size = min(chip->intern_res_poll_count, UG3105_MOV_AVG_WINDOW); + for (i = 0; i < win_size; i++) + chip->intern_res_avg += chip->intern_res[i]; + chip->intern_res_avg /= win_size; + +out: + mutex_unlock(&chip->lock); + + queue_delayed_work(system_wq, &chip->work, + (chip->poll_count <= UG3105_INIT_POLL_COUNT) ? + UG3105_INIT_POLL_TIME : UG3105_POLL_TIME); + + if (chip->status != prev_status && psy) + power_supply_changed(psy); +} + +static enum power_supply_property ug3105_battery_props[] = { + POWER_SUPPLY_PROP_STATUS, + POWER_SUPPLY_PROP_PRESENT, + POWER_SUPPLY_PROP_TECHNOLOGY, + POWER_SUPPLY_PROP_SCOPE, + POWER_SUPPLY_PROP_VOLTAGE_NOW, + POWER_SUPPLY_PROP_VOLTAGE_OCV, + POWER_SUPPLY_PROP_CURRENT_NOW, + POWER_SUPPLY_PROP_CAPACITY, +}; + +static int ug3105_get_property(struct power_supply *psy, + enum power_supply_property psp, + union power_supply_propval *val) +{ + struct ug3105_chip *chip = power_supply_get_drvdata(psy); + int ret = 0; + + mutex_lock(&chip->lock); + + if (!chip->psy) { + ret = -EAGAIN; + goto out; + } + + switch (psp) { + case POWER_SUPPLY_PROP_STATUS: + val->intval = chip->status; + break; + case POWER_SUPPLY_PROP_PRESENT: + val->intval = 1; + break; + case POWER_SUPPLY_PROP_TECHNOLOGY: + val->intval = chip->info->technology; + break; + case POWER_SUPPLY_PROP_SCOPE: + val->intval = POWER_SUPPLY_SCOPE_SYSTEM; + break; + case POWER_SUPPLY_PROP_VOLTAGE_NOW: + ret = ug3105_read_word(chip->client, UG3105_REG_BAT_VOLT); + if (ret < 0) + break; + val->intval = ret * chip->uv_per_unit; + ret = 0; + break; + case POWER_SUPPLY_PROP_VOLTAGE_OCV: + val->intval = chip->ocv_avg; + break; + case POWER_SUPPLY_PROP_CURRENT_NOW: + ret = ug3105_read_word(chip->client, UG3105_REG_BAT_CURR); + if (ret < 0) + break; + val->intval = (s16)ret * chip->ua_per_unit; + ret = 0; + break; + case POWER_SUPPLY_PROP_CAPACITY: + val->intval = chip->capacity; + break; + default: + ret = -EINVAL; + } + +out: + mutex_unlock(&chip->lock); + return ret; +} + +static void ug3105_external_power_changed(struct power_supply *psy) +{ + struct ug3105_chip *chip = power_supply_get_drvdata(psy); + + dev_dbg(&chip->client->dev, "external power changed\n"); + mod_delayed_work(system_wq, &chip->work, UG3105_SETTLE_TIME); +} + +static const struct power_supply_desc ug3105_psy_desc = { + .name = "ug3105_battery", + .type = POWER_SUPPLY_TYPE_BATTERY, + .get_property = ug3105_get_property, + .external_power_changed = ug3105_external_power_changed, + .properties = ug3105_battery_props, + .num_properties = ARRAY_SIZE(ug3105_battery_props), +}; + +static void ug3105_init(struct ug3105_chip *chip) +{ + chip->poll_count = 0; + chip->ocv_avg_index = 0; + chip->total_coulomb_count = 0; + i2c_smbus_write_byte_data(chip->client, UG3105_REG_MODE, + UG3105_MODE_RUN); + i2c_smbus_write_byte_data(chip->client, UG3105_REG_CTRL1, + UG3105_CTRL1_RESET_COULOMB_CNT); + queue_delayed_work(system_wq, &chip->work, 0); + flush_delayed_work(&chip->work); +} + +static int ug3105_probe(struct i2c_client *client) +{ + struct power_supply_config psy_cfg = {}; + struct device *dev = &client->dev; + u32 curr_sense_res_uohm = 10000; + struct power_supply *psy; + struct ug3105_chip *chip; + int ret; + + chip = devm_kzalloc(dev, sizeof(*chip), GFP_KERNEL); + if (!chip) + return -ENOMEM; + + chip->client = client; + mutex_init(&chip->lock); + ret = devm_delayed_work_autocancel(dev, &chip->work, ug3105_work); + if (ret) + return ret; + + psy_cfg.drv_data = chip; + psy = devm_power_supply_register(dev, &ug3105_psy_desc, &psy_cfg); + if (IS_ERR(psy)) + return PTR_ERR(psy); + + ret = power_supply_get_battery_info(psy, &chip->info); + if (ret) + return ret; + + if (chip->info->factory_internal_resistance_uohm == -EINVAL || + chip->info->constant_charge_voltage_max_uv == -EINVAL) { + dev_err(dev, "error required properties are missing\n"); + return -ENODEV; + } + + device_property_read_u32(dev, "upi,rsns-microohm", &curr_sense_res_uohm); + + /* + * DAC maximum is 4.5V divided by 65536 steps + an unknown factor of 10 + * coming from somewhere for some reason (verified with a volt-meter). + */ + chip->uv_per_unit = 45000000/65536; + /* Datasheet says 8.1 uV per unit for the current ADC */ + chip->ua_per_unit = 8100000 / curr_sense_res_uohm; + + /* Use provided internal resistance as start point (in milli-ohm) */ + chip->intern_res_avg = chip->info->factory_internal_resistance_uohm / 1000; + /* Also add it to the internal resistance moving average window */ + chip->intern_res[0] = chip->intern_res_avg; + chip->intern_res_avg_index = 1; + chip->intern_res_poll_count = 1; + + mutex_lock(&chip->lock); + chip->psy = psy; + mutex_unlock(&chip->lock); + + ug3105_init(chip); + + i2c_set_clientdata(client, chip); + return 0; +} + +static int __maybe_unused ug3105_suspend(struct device *dev) +{ + struct ug3105_chip *chip = dev_get_drvdata(dev); + + cancel_delayed_work_sync(&chip->work); + i2c_smbus_write_byte_data(chip->client, UG3105_REG_MODE, + UG3105_MODE_STANDBY); + + return 0; +} + +static int __maybe_unused ug3105_resume(struct device *dev) +{ + struct ug3105_chip *chip = dev_get_drvdata(dev); + + ug3105_init(chip); + + return 0; +} + +static SIMPLE_DEV_PM_OPS(ug3105_pm_ops, ug3105_suspend, + ug3105_resume); + +static const struct i2c_device_id ug3105_id[] = { + { "ug3105" }, + { } +}; +MODULE_DEVICE_TABLE(i2c, ug3105_id); + +static struct i2c_driver ug3105_i2c_driver = { + .driver = { + .name = "ug3105", + .pm = &ug3105_pm_ops, + }, + .probe_new = ug3105_probe, + .id_table = ug3105_id, +}; +module_i2c_driver(ug3105_i2c_driver); + +MODULE_AUTHOR("Hans de Goede <hdegoede@redhat.com"); +MODULE_DESCRIPTION("uPI uG3105 battery monitor driver"); +MODULE_LICENSE("GPL");
Add a new battery 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. So far this driver is only used on x86/ACPI (non devicetree) devs (also note there is no of_match table). Therefor there is no devicetree bindings documentation for this driver's "upi,rsns-microohm" property since this is not used in actual devicetree files and the dt bindings maintainers have requested properties with no actual dt users to _not_ be added to the dt bindings. The property's name has been chosen so that it should not need to be changed if/when devicetree enumeration support gets added later, as it mirrors "maxim,rsns-microohm" from the "maxim,max17042" bindings. Signed-off-by: Hans de Goede <hdegoede@redhat.com> --- drivers/power/supply/Kconfig | 15 + drivers/power/supply/Makefile | 1 + drivers/power/supply/ug3105_battery.c | 486 ++++++++++++++++++++++++++ 3 files changed, 502 insertions(+) create mode 100644 drivers/power/supply/ug3105_battery.c