linux/Documentation/ABI/testing/sysfs-class-power
Bastien Nocera f0cf057594 ABI: testing: sysfs-class-power: Document absence of "present" property
Document how the absence of the "present" property in the sysfs
power_supply class should be handled.

Link: https://gitlab.freedesktop.org/upower/upower/-/merge_requests/173
Cc: Mario Limonciello <mario.limonciello@amd.com>
Signed-off-by: Bastien Nocera <hadess@hadess.net>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
2023-02-25 01:16:50 +01:00

775 lines
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**General Properties**
What: /sys/class/power_supply/<supply_name>/manufacturer
Date: May 2007
Contact: linux-pm@vger.kernel.org
Description:
Reports the name of the device manufacturer.
Access: Read
Valid values: Represented as string
What: /sys/class/power_supply/<supply_name>/model_name
Date: May 2007
Contact: linux-pm@vger.kernel.org
Description:
Reports the name of the device model.
Access: Read
Valid values: Represented as string
What: /sys/class/power_supply/<supply_name>/serial_number
Date: January 2008
Contact: linux-pm@vger.kernel.org
Description:
Reports the serial number of the device.
Access: Read
Valid values: Represented as string
What: /sys/class/power_supply/<supply_name>/type
Date: May 2010
Contact: linux-pm@vger.kernel.org
Description:
Describes the main type of the supply.
Access: Read
Valid values: "Battery", "UPS", "Mains", "USB", "Wireless"
**Battery and USB properties**
What: /sys/class/power_supply/<supply_name>/current_avg
Date: May 2007
Contact: linux-pm@vger.kernel.org
Description:
Battery:
Reports an average IBAT current reading for the battery, over
a fixed period. Normally devices will provide a fixed interval
in which they average readings to smooth out the reported
value.
USB:
Reports an average IBUS current reading over a fixed period.
Normally devices will provide a fixed interval in which they
average readings to smooth out the reported value.
Access: Read
Valid values: Represented in microamps. Negative values are
used for discharging batteries, positive values for charging
batteries and for USB IBUS current.
What: /sys/class/power_supply/<supply_name>/current_max
Date: October 2010
Contact: linux-pm@vger.kernel.org
Description:
Battery:
Reports the maximum IBAT current allowed into the battery.
USB:
Reports the maximum IBUS current the supply can support.
Access: Read
Valid values: Represented in microamps
What: /sys/class/power_supply/<supply_name>/current_now
Date: May 2007
Contact: linux-pm@vger.kernel.org
Description:
Battery:
Reports an instant, single IBAT current reading for the
battery. This value is not averaged/smoothed.
Access: Read
USB:
Reports the IBUS current supplied now. This value is generally
read-only reporting, unless the 'online' state of the supply
is set to be programmable, in which case this value can be set
within the reported min/max range.
Access: Read, Write
Valid values: Represented in microamps. Negative values are
used for discharging batteries, positive values for charging
batteries and for USB IBUS current.
What: /sys/class/power_supply/<supply_name>/temp
Date: May 2007
Contact: linux-pm@vger.kernel.org
Description:
Battery:
Reports the current TBAT battery temperature reading.
USB:
Reports the current supply temperature reading. This would
normally be the internal temperature of the device itself
(e.g TJUNC temperature of an IC)
Access: Read
Valid values: Represented in 1/10 Degrees Celsius
What: /sys/class/power_supply/<supply_name>/temp_alert_max
Date: July 2012
Contact: linux-pm@vger.kernel.org
Description:
Battery:
Maximum TBAT temperature trip-wire value where the supply will
notify user-space of the event.
USB:
Maximum supply temperature trip-wire value where the supply
will notify user-space of the event.
This is normally used for the charging scenario where
user-space needs to know if the temperature has crossed an
upper threshold so it can take appropriate action (e.g. warning
user that the temperature is critically high, and charging has
stopped).
Access: Read
Valid values: Represented in 1/10 Degrees Celsius
What: /sys/class/power_supply/<supply_name>/temp_alert_min
Date: July 2012
Contact: linux-pm@vger.kernel.org
Description:
Battery:
Minimum TBAT temperature trip-wire value where the supply will
notify user-space of the event.
USB:
Minimum supply temperature trip-wire value where the supply
will notify user-space of the event.
This is normally used for the charging scenario where user-space
needs to know if the temperature has crossed a lower threshold
so it can take appropriate action (e.g. warning user that
temperature level is high, and charging current has been
reduced accordingly to remedy the situation).
Access: Read
Valid values: Represented in 1/10 Degrees Celsius
What: /sys/class/power_supply/<supply_name>/temp_max
Date: July 2014
Contact: linux-pm@vger.kernel.org
Description:
Battery:
Reports the maximum allowed TBAT battery temperature for
charging.
USB:
Reports the maximum allowed supply temperature for operation.
Access: Read
Valid values: Represented in 1/10 Degrees Celsius
What: /sys/class/power_supply/<supply_name>/temp_min
Date: July 2014
Contact: linux-pm@vger.kernel.org
Description:
Battery:
Reports the minimum allowed TBAT battery temperature for
charging.
USB:
Reports the minimum allowed supply temperature for operation.
Access: Read
Valid values: Represented in 1/10 Degrees Celsius
What: /sys/class/power_supply/<supply_name>/voltage_max,
Date: January 2008
Contact: linux-pm@vger.kernel.org
Description:
Battery:
Reports the maximum safe VBAT voltage permitted for the
battery, during charging.
USB:
Reports the maximum VBUS voltage the supply can support.
Access: Read
Valid values: Represented in microvolts
What: /sys/class/power_supply/<supply_name>/voltage_min,
Date: January 2008
Contact: linux-pm@vger.kernel.org
Description:
Battery:
Reports the minimum safe VBAT voltage permitted for the
battery, during discharging.
USB:
Reports the minimum VBUS voltage the supply can support.
Access: Read
Valid values: Represented in microvolts
What: /sys/class/power_supply/<supply_name>/voltage_now,
Date: May 2007
Contact: linux-pm@vger.kernel.org
Description:
Battery:
Reports an instant, single VBAT voltage reading for the
battery. This value is not averaged/smoothed.
Access: Read
USB:
Reports the VBUS voltage supplied now. This value is generally
read-only reporting, unless the 'online' state of the supply
is set to be programmable, in which case this value can be set
within the reported min/max range.
Access: Read, Write
Valid values: Represented in microvolts
**Battery Properties**
What: /sys/class/power_supply/<supply_name>/capacity
Date: May 2007
Contact: linux-pm@vger.kernel.org
Description:
Fine grain representation of battery capacity.
Access: Read
Valid values: 0 - 100 (percent)
What: /sys/class/power_supply/<supply_name>/capacity_alert_max
Date: July 2012
Contact: linux-pm@vger.kernel.org
Description:
Maximum battery capacity trip-wire value where the supply will
notify user-space of the event. This is normally used for the
battery discharging scenario where user-space needs to know the
battery has dropped to an upper level so it can take
appropriate action (e.g. warning user that battery level is
low).
Access: Read, Write
Valid values: 0 - 100 (percent)
What: /sys/class/power_supply/<supply_name>/capacity_alert_min
Date: July 2012
Contact: linux-pm@vger.kernel.org
Description:
Minimum battery capacity trip-wire value where the supply will
notify user-space of the event. This is normally used for the
battery discharging scenario where user-space needs to know the
battery has dropped to a lower level so it can take
appropriate action (e.g. warning user that battery level is
critically low).
Access: Read, Write
Valid values: 0 - 100 (percent)
What: /sys/class/power_supply/<supply_name>/capacity_error_margin
Date: April 2019
Contact: linux-pm@vger.kernel.org
Description:
Battery capacity measurement becomes unreliable without
recalibration. This values provides the maximum error
margin expected to exist by the fuel gauge in percent.
Values close to 0% will be returned after (re-)calibration
has happened. Over time the error margin will increase.
100% means, that the capacity related values are basically
completely useless.
Access: Read
Valid values: 0 - 100 (percent)
What: /sys/class/power_supply/<supply_name>/capacity_level
Date: June 2009
Contact: linux-pm@vger.kernel.org
Description:
Coarse representation of battery capacity.
Access: Read
Valid values:
"Unknown", "Critical", "Low", "Normal", "High",
"Full"
What: /sys/class/power_supply/<supply_name>/charge_control_limit
Date: Oct 2012
Contact: linux-pm@vger.kernel.org
Description:
Maximum allowable charging current. Used for charge rate
throttling for thermal cooling or improving battery health.
Access: Read, Write
Valid values: Represented in microamps
What: /sys/class/power_supply/<supply_name>/charge_control_limit_max
Date: Oct 2012
Contact: linux-pm@vger.kernel.org
Description:
Maximum legal value for the charge_control_limit property.
Access: Read
Valid values: Represented in microamps
What: /sys/class/power_supply/<supply_name>/charge_control_start_threshold
Date: April 2019
Contact: linux-pm@vger.kernel.org
Description:
Represents a battery percentage level, below which charging will
begin.
Access: Read, Write
Valid values: 0 - 100 (percent)
What: /sys/class/power_supply/<supply_name>/charge_control_end_threshold
Date: April 2019
Contact: linux-pm@vger.kernel.org
Description:
Represents a battery percentage level, above which charging will
stop. Not all hardware is capable of setting this to an arbitrary
percentage. Drivers will round written values to the nearest
supported value. Reading back the value will show the actual
threshold set by the driver.
Access: Read, Write
Valid values: 0 - 100 (percent)
What: /sys/class/power_supply/<supply_name>/charge_type
Date: July 2009
Contact: linux-pm@vger.kernel.org
Description:
Represents the type of charging currently being applied to the
battery. "Trickle", "Fast", and "Standard" all mean different
charging speeds. "Adaptive" means that the charger uses some
algorithm to adjust the charge rate dynamically, without
any user configuration required. "Custom" means that the charger
uses the charge_control_* properties as configuration for some
different algorithm. "Long Life" means the charger reduces its
charging rate in order to prolong the battery health. "Bypass"
means the charger bypasses the charging path around the
integrated converter allowing for a "smart" wall adaptor to
perform the power conversion externally.
Access: Read, Write
Valid values:
"Unknown", "N/A", "Trickle", "Fast", "Standard",
"Adaptive", "Custom", "Long Life", "Bypass"
What: /sys/class/power_supply/<supply_name>/charge_term_current
Date: July 2014
Contact: linux-pm@vger.kernel.org
Description:
Reports the charging current value which is used to determine
when the battery is considered full and charging should end.
Access: Read
Valid values: Represented in microamps
What: /sys/class/power_supply/<supply_name>/health
Date: May 2007
Contact: linux-pm@vger.kernel.org
Description:
Reports the health of the battery or battery side of charger
functionality.
Access: Read
Valid values:
"Unknown", "Good", "Overheat", "Dead",
"Over voltage", "Unspecified failure", "Cold",
"Watchdog timer expire", "Safety timer expire",
"Over current", "Calibration required", "Warm",
"Cool", "Hot", "No battery"
What: /sys/class/power_supply/<supply_name>/precharge_current
Date: June 2017
Contact: linux-pm@vger.kernel.org
Description:
Reports the charging current applied during pre-charging phase
for a battery charge cycle.
Access: Read
Valid values: Represented in microamps
What: /sys/class/power_supply/<supply_name>/present
Date: May 2007
Contact: linux-pm@vger.kernel.org
Description:
Reports whether a battery is present or not in the system. If the
property does not exist, the battery is considered to be present.
Access: Read
Valid values:
== =======
0: Absent
1: Present
== =======
What: /sys/class/power_supply/<supply_name>/status
Date: May 2007
Contact: linux-pm@vger.kernel.org
Description:
Represents the charging status of the battery. Normally this
is read-only reporting although for some supplies this can be
used to enable/disable charging to the battery.
Access: Read, Write
Valid values:
"Unknown", "Charging", "Discharging",
"Not charging", "Full"
What: /sys/class/power_supply/<supply_name>/charge_behaviour
Date: November 2021
Contact: linux-pm@vger.kernel.org
Description:
Represents the charging behaviour.
Access: Read, Write
Valid values:
================ ====================================
auto: Charge normally, respect thresholds
inhibit-charge: Do not charge while AC is attached
force-discharge: Force discharge while AC is attached
================ ====================================
What: /sys/class/power_supply/<supply_name>/technology
Date: May 2007
Contact: linux-pm@vger.kernel.org
Description:
Describes the battery technology supported by the supply.
Access: Read
Valid values:
"Unknown", "NiMH", "Li-ion", "Li-poly", "LiFe",
"NiCd", "LiMn"
What: /sys/class/power_supply/<supply_name>/voltage_avg,
Date: May 2007
Contact: linux-pm@vger.kernel.org
Description:
Reports an average VBAT voltage reading for the battery, over a
fixed period. Normally devices will provide a fixed interval in
which they average readings to smooth out the reported value.
Access: Read
Valid values: Represented in microvolts
What: /sys/class/power_supply/<supply_name>/cycle_count
Date: January 2010
Contact: linux-pm@vger.kernel.org
Description:
Reports the number of full charge + discharge cycles the
battery has undergone.
Access: Read
Valid values:
Integer > 0: representing full cycles
Integer = 0: cycle_count info is not available
**USB Properties**
What: /sys/class/power_supply/<supply_name>/input_current_limit
Date: July 2014
Contact: linux-pm@vger.kernel.org
Description:
Details the incoming IBUS current limit currently set in the
supply. Normally this is configured based on the type of
connection made (e.g. A configured SDP should output a maximum
of 500mA so the input current limit is set to the same value).
Use preferably input_power_limit, and for problems that can be
solved using power limit use input_current_limit.
Access: Read, Write
Valid values: Represented in microamps
What: /sys/class/power_supply/<supply_name>/input_voltage_limit
Date: May 2019
Contact: linux-pm@vger.kernel.org
Description:
This entry configures the incoming VBUS voltage limit currently
set in the supply. Normally this is configured based on
system-level knowledge or user input (e.g. This is part of the
Pixel C's thermal management strategy to effectively limit the
input power to 5V when the screen is on to meet Google's skin
temperature targets). Note that this feature should not be
used for safety critical things.
Use preferably input_power_limit, and for problems that can be
solved using power limit use input_voltage_limit.
Access: Read, Write
Valid values: Represented in microvolts
What: /sys/class/power_supply/<supply_name>/input_power_limit
Date: May 2019
Contact: linux-pm@vger.kernel.org
Description:
This entry configures the incoming power limit currently set
in the supply. Normally this is configured based on
system-level knowledge or user input. Use preferably this
feature to limit the incoming power and use current/voltage
limit only for problems that can be solved using power limit.
Access: Read, Write
Valid values: Represented in microwatts
What: /sys/class/power_supply/<supply_name>/online,
Date: May 2007
Contact: linux-pm@vger.kernel.org
Description:
Indicates if VBUS is present for the supply. When the supply is
online, and the supply allows it, then it's possible to switch
between online states (e.g. Fixed -> Programmable for a PD_PPS
USB supply so voltage and current can be controlled).
Access: Read, Write
Valid values:
== ==================================================
0: Offline
1: Online Fixed - Fixed Voltage Supply
2: Online Programmable - Programmable Voltage Supply
== ==================================================
What: /sys/class/power_supply/<supply_name>/usb_type
Date: March 2018
Contact: linux-pm@vger.kernel.org
Description:
Reports what type of USB connection is currently active for
the supply, for example it can show if USB-PD capable source
is attached.
Access: Read-Only
Valid values:
"Unknown", "SDP", "DCP", "CDP", "ACA", "C", "PD",
"PD_DRP", "PD_PPS", "BrickID"
**Device Specific Properties**
What: /sys/class/power/ds2760-battery.*/charge_now
Date: May 2010
KernelVersion: 2.6.35
Contact: Daniel Mack <daniel@caiaq.de>
Description:
This file is writeable and can be used to set the current
coloumb counter value inside the battery monitor chip. This
is needed for unavoidable corrections of aging batteries.
A userspace daemon can monitor the battery charging logic
and once the counter drops out of considerable bounds, take
appropriate action.
What: /sys/class/power/ds2760-battery.*/charge_full
Date: May 2010
KernelVersion: 2.6.35
Contact: Daniel Mack <daniel@caiaq.de>
Description:
This file is writeable and can be used to set the assumed
battery 'full level'. As batteries age, this value has to be
amended over time.
What: /sys/class/power_supply/max14577-charger/device/fast_charge_timer
Date: October 2014
KernelVersion: 3.18.0
Contact: Krzysztof Kozlowski <krzk@kernel.org>
Description:
This entry shows and sets the maximum time the max14577
charger operates in fast-charge mode. When the timer expires
the device will terminate fast-charge mode (charging current
will drop to 0 A) and will trigger interrupt.
Valid values:
- 5, 6 or 7 (hours),
- 0: disabled.
What: /sys/class/power_supply/max77693-charger/device/fast_charge_timer
Date: January 2015
KernelVersion: 3.19.0
Contact: Krzysztof Kozlowski <krzk@kernel.org>
Description:
This entry shows and sets the maximum time the max77693
charger operates in fast-charge mode. When the timer expires
the device will terminate fast-charge mode (charging current
will drop to 0 A) and will trigger interrupt.
Valid values:
- 4 - 16 (hours), step by 2 (rounded down)
- 0: disabled.
What: /sys/class/power_supply/max77693-charger/device/top_off_threshold_current
Date: January 2015
KernelVersion: 3.19.0
Contact: Krzysztof Kozlowski <krzk@kernel.org>
Description:
This entry shows and sets the charging current threshold for
entering top-off charging mode. When charging current in fast
charge mode drops below this value, the charger will trigger
interrupt and start top-off charging mode.
Valid values:
- 100000 - 200000 (microamps), step by 25000 (rounded down)
- 200000 - 350000 (microamps), step by 50000 (rounded down)
- 0: disabled.
What: /sys/class/power_supply/max77693-charger/device/top_off_timer
Date: January 2015
KernelVersion: 3.19.0
Contact: Krzysztof Kozlowski <krzk@kernel.org>
Description:
This entry shows and sets the maximum time the max77693
charger operates in top-off charge mode. When the timer expires
the device will terminate top-off charge mode (charging current
will drop to 0 A) and will trigger interrupt.
Valid values:
- 0 - 70 (minutes), step by 10 (rounded down)
What: /sys/class/power_supply/bq24257-charger/ovp_voltage
Date: October 2015
KernelVersion: 4.4.0
Contact: Andreas Dannenberg <dannenberg@ti.com>
Description:
This entry configures the overvoltage protection feature of bq24257-
type charger devices. This feature protects the device and other
components against damage from overvoltage on the input supply. See
device datasheet for details.
Valid values:
- 6000000, 6500000, 7000000, 8000000, 9000000, 9500000, 10000000,
10500000 (all uV)
What: /sys/class/power_supply/bq24257-charger/in_dpm_voltage
Date: October 2015
KernelVersion: 4.4.0
Contact: Andreas Dannenberg <dannenberg@ti.com>
Description:
This entry configures the input dynamic power path management voltage of
bq24257-type charger devices. Once the supply drops to the configured
voltage, the input current limit is reduced down to prevent the further
drop of the supply. When the IC enters this mode, the charge current is
lower than the set value. See device datasheet for details.
Valid values:
- 4200000, 4280000, 4360000, 4440000, 4520000, 4600000, 4680000,
4760000 (all uV)
What: /sys/class/power_supply/bq24257-charger/high_impedance_enable
Date: October 2015
KernelVersion: 4.4.0
Contact: Andreas Dannenberg <dannenberg@ti.com>
Description:
This entry allows enabling the high-impedance mode of bq24257-type
charger devices. If enabled, it places the charger IC into low power
standby mode with the switch mode controller disabled. When disabled,
the charger operates normally. See device datasheet for details.
Valid values:
- 1: enabled
- 0: disabled
What: /sys/class/power_supply/bq24257-charger/sysoff_enable
Date: October 2015
KernelVersion: 4.4.0
Contact: Andreas Dannenberg <dannenberg@ti.com>
Description:
This entry allows enabling the sysoff mode of bq24257-type charger
devices. If enabled and the input is removed, the internal battery FET
is turned off in order to reduce the leakage from the BAT pin to less
than 1uA. Note that on some devices/systems this disconnects the battery
from the system. See device datasheet for details.
Valid values:
- 1: enabled
- 0: disabled
What: /sys/class/power_supply/<supply_name>/manufacture_year
Date: January 2020
Contact: linux-pm@vger.kernel.org
Description:
Reports the year (following Gregorian calendar) when the device has been
manufactured.
Access: Read
Valid values: Reported as integer
What: /sys/class/power_supply/<supply_name>/manufacture_month
Date: January 2020
Contact: linux-pm@vger.kernel.org
Description:
Reports the month when the device has been manufactured.
Access: Read
Valid values: 1-12
What: /sys/class/power_supply/<supply_name>/manufacture_day
Date: January 2020
Contact: linux-pm@vger.kernel.org
Description:
Reports the day of month when the device has been manufactured.
Access: Read
Valid values: 1-31