mirror of
git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
synced 2026-03-22 07:27:12 +08:00
docs: power: clean up power_supply_class.rst
Clean up grammar, punctuation, etc., in the power supply class documentation. Add article adjectives where needed. Hyphenate some adjectives. Fix punctuation. Fix some verb usage (singular/plural). Fix run-on sentences. Add "is" in a few places. Change "QA" to "Q&A". Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Reviewed-by: Dhruva Gole <d-gole@ti.com> Link: https://patch.msgid.link/20251014182008.823980-1-rdunlap@infradead.org Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
This commit is contained in:
committed by
Sebastian Reichel
parent
446fcf4946
commit
06b54f2d74
@@ -7,35 +7,35 @@ Synopsis
|
|||||||
Power supply class used to represent battery, UPS, AC or DC power supply
|
Power supply class used to represent battery, UPS, AC or DC power supply
|
||||||
properties to user-space.
|
properties to user-space.
|
||||||
|
|
||||||
It defines core set of attributes, which should be applicable to (almost)
|
It defines a core set of attributes which should be applicable to (almost)
|
||||||
every power supply out there. Attributes are available via sysfs and uevent
|
every power supply out there. Attributes are available via sysfs and uevent
|
||||||
interfaces.
|
interfaces.
|
||||||
|
|
||||||
Each attribute has well defined meaning, up to unit of measure used. While
|
Each attribute has a well-defined meaning, up to the unit of measure used. While
|
||||||
the attributes provided are believed to be universally applicable to any
|
the attributes provided are believed to be universally applicable to any
|
||||||
power supply, specific monitoring hardware may not be able to provide them
|
power supply, specific monitoring hardware may not be able to provide them
|
||||||
all, so any of them may be skipped.
|
all, so any of them may be skipped.
|
||||||
|
|
||||||
Power supply class is extensible, and allows to define drivers own attributes.
|
The power supply class is extensible and allows drivers to define their own
|
||||||
The core attribute set is subject to the standard Linux evolution (i.e.
|
attributes. The core attribute set is subject to the standard Linux evolution
|
||||||
if it will be found that some attribute is applicable to many power supply
|
(i.e., if some attribute is found to be applicable to many power
|
||||||
types or their drivers, it can be added to the core set).
|
supply types or their drivers, it can be added to the core set).
|
||||||
|
|
||||||
It also integrates with LED framework, for the purpose of providing
|
It also integrates with the LED framework, for the purpose of providing
|
||||||
typically expected feedback of battery charging/fully charged status and
|
typically expected feedback of battery charging/fully charged status and
|
||||||
AC/USB power supply online status. (Note that specific details of the
|
AC/USB power supply online status. (Note that specific details of the
|
||||||
indication (including whether to use it at all) are fully controllable by
|
indication (including whether to use it at all) are fully controllable by
|
||||||
user and/or specific machine defaults, per design principles of LED
|
user and/or specific machine defaults, per design principles of the LED
|
||||||
framework).
|
framework.)
|
||||||
|
|
||||||
|
|
||||||
Attributes/properties
|
Attributes/properties
|
||||||
~~~~~~~~~~~~~~~~~~~~~
|
~~~~~~~~~~~~~~~~~~~~~
|
||||||
Power supply class has predefined set of attributes, this eliminates code
|
The power supply class has a predefined set of attributes. This eliminates code
|
||||||
duplication across drivers. Power supply class insist on reusing its
|
duplication across drivers. The power supply class insists on reusing its
|
||||||
predefined attributes *and* their units.
|
predefined attributes *and* their units.
|
||||||
|
|
||||||
So, userspace gets predictable set of attributes and their units for any
|
So, userspace gets a predictable set of attributes and their units for any
|
||||||
kind of power supply, and can process/present them to a user in consistent
|
kind of power supply, and can process/present them to a user in consistent
|
||||||
manner. Results for different power supplies and machines are also directly
|
manner. Results for different power supplies and machines are also directly
|
||||||
comparable.
|
comparable.
|
||||||
@@ -61,7 +61,7 @@ Attributes/properties detailed
|
|||||||
| **Charge/Energy/Capacity - how to not confuse** |
|
| **Charge/Energy/Capacity - how to not confuse** |
|
||||||
+--------------------------------------------------------------------------+
|
+--------------------------------------------------------------------------+
|
||||||
| **Because both "charge" (µAh) and "energy" (µWh) represents "capacity" |
|
| **Because both "charge" (µAh) and "energy" (µWh) represents "capacity" |
|
||||||
| of battery, this class distinguish these terms. Don't mix them!** |
|
| of battery, this class distinguishes these terms. Don't mix them!** |
|
||||||
| |
|
| |
|
||||||
| - `CHARGE_*` |
|
| - `CHARGE_*` |
|
||||||
| attributes represents capacity in µAh only. |
|
| attributes represents capacity in µAh only. |
|
||||||
@@ -81,7 +81,7 @@ _NOW
|
|||||||
|
|
||||||
STATUS
|
STATUS
|
||||||
this attribute represents operating status (charging, full,
|
this attribute represents operating status (charging, full,
|
||||||
discharging (i.e. powering a load), etc.). This corresponds to
|
discharging (i.e., powering a load), etc.). This corresponds to
|
||||||
`BATTERY_STATUS_*` values, as defined in battery.h.
|
`BATTERY_STATUS_*` values, as defined in battery.h.
|
||||||
|
|
||||||
CHARGE_TYPE
|
CHARGE_TYPE
|
||||||
@@ -92,10 +92,10 @@ CHARGE_TYPE
|
|||||||
|
|
||||||
AUTHENTIC
|
AUTHENTIC
|
||||||
indicates the power supply (battery or charger) connected
|
indicates the power supply (battery or charger) connected
|
||||||
to the platform is authentic(1) or non authentic(0).
|
to the platform is authentic(1) or non-authentic(0).
|
||||||
|
|
||||||
HEALTH
|
HEALTH
|
||||||
represents health of the battery, values corresponds to
|
represents health of the battery. Values corresponds to
|
||||||
POWER_SUPPLY_HEALTH_*, defined in battery.h.
|
POWER_SUPPLY_HEALTH_*, defined in battery.h.
|
||||||
|
|
||||||
VOLTAGE_OCV
|
VOLTAGE_OCV
|
||||||
@@ -103,11 +103,11 @@ VOLTAGE_OCV
|
|||||||
|
|
||||||
VOLTAGE_MAX_DESIGN, VOLTAGE_MIN_DESIGN
|
VOLTAGE_MAX_DESIGN, VOLTAGE_MIN_DESIGN
|
||||||
design values for maximal and minimal power supply voltages.
|
design values for maximal and minimal power supply voltages.
|
||||||
Maximal/minimal means values of voltages when battery considered
|
Maximal/minimal means values of voltages when battery is considered
|
||||||
"full"/"empty" at normal conditions. Yes, there is no direct relation
|
"full"/"empty" at normal conditions. Yes, there is no direct relation
|
||||||
between voltage and battery capacity, but some dumb
|
between voltage and battery capacity, but some dumb
|
||||||
batteries use voltage for very approximated calculation of capacity.
|
batteries use voltage for very approximated calculation of capacity.
|
||||||
Battery driver also can use this attribute just to inform userspace
|
A battery driver also can use this attribute just to inform userspace
|
||||||
about maximal and minimal voltage thresholds of a given battery.
|
about maximal and minimal voltage thresholds of a given battery.
|
||||||
|
|
||||||
VOLTAGE_MAX, VOLTAGE_MIN
|
VOLTAGE_MAX, VOLTAGE_MIN
|
||||||
@@ -122,16 +122,16 @@ CURRENT_BOOT
|
|||||||
Reports the current measured during boot
|
Reports the current measured during boot
|
||||||
|
|
||||||
CHARGE_FULL_DESIGN, CHARGE_EMPTY_DESIGN
|
CHARGE_FULL_DESIGN, CHARGE_EMPTY_DESIGN
|
||||||
design charge values, when battery considered full/empty.
|
design charge values, when battery is considered full/empty.
|
||||||
|
|
||||||
ENERGY_FULL_DESIGN, ENERGY_EMPTY_DESIGN
|
ENERGY_FULL_DESIGN, ENERGY_EMPTY_DESIGN
|
||||||
same as above but for energy.
|
same as above but for energy.
|
||||||
|
|
||||||
CHARGE_FULL, CHARGE_EMPTY
|
CHARGE_FULL, CHARGE_EMPTY
|
||||||
These attributes means "last remembered value of charge when battery
|
These attributes mean "last remembered value of charge when battery
|
||||||
became full/empty". It also could mean "value of charge when battery
|
became full/empty". They also could mean "value of charge when battery is
|
||||||
considered full/empty at given conditions (temperature, age)".
|
considered full/empty at given conditions (temperature, age)".
|
||||||
I.e. these attributes represents real thresholds, not design values.
|
I.e., these attributes represents real thresholds, not design values.
|
||||||
|
|
||||||
ENERGY_FULL, ENERGY_EMPTY
|
ENERGY_FULL, ENERGY_EMPTY
|
||||||
same as above but for energy.
|
same as above but for energy.
|
||||||
@@ -153,12 +153,12 @@ CHARGE_TERM_CURRENT
|
|||||||
CONSTANT_CHARGE_CURRENT
|
CONSTANT_CHARGE_CURRENT
|
||||||
constant charge current programmed by charger.
|
constant charge current programmed by charger.
|
||||||
|
|
||||||
|
|
||||||
CONSTANT_CHARGE_CURRENT_MAX
|
CONSTANT_CHARGE_CURRENT_MAX
|
||||||
maximum charge current supported by the power supply object.
|
maximum charge current supported by the power supply object.
|
||||||
|
|
||||||
CONSTANT_CHARGE_VOLTAGE
|
CONSTANT_CHARGE_VOLTAGE
|
||||||
constant charge voltage programmed by charger.
|
constant charge voltage programmed by charger.
|
||||||
|
|
||||||
CONSTANT_CHARGE_VOLTAGE_MAX
|
CONSTANT_CHARGE_VOLTAGE_MAX
|
||||||
maximum charge voltage supported by the power supply object.
|
maximum charge voltage supported by the power supply object.
|
||||||
|
|
||||||
@@ -208,10 +208,10 @@ TEMP_MAX
|
|||||||
|
|
||||||
TIME_TO_EMPTY
|
TIME_TO_EMPTY
|
||||||
seconds left for battery to be considered empty
|
seconds left for battery to be considered empty
|
||||||
(i.e. while battery powers a load)
|
(i.e., while battery powers a load)
|
||||||
TIME_TO_FULL
|
TIME_TO_FULL
|
||||||
seconds left for battery to be considered full
|
seconds left for battery to be considered full
|
||||||
(i.e. while battery is charging)
|
(i.e., while battery is charging)
|
||||||
|
|
||||||
|
|
||||||
Battery <-> external power supply interaction
|
Battery <-> external power supply interaction
|
||||||
@@ -220,13 +220,13 @@ Often power supplies are acting as supplies and supplicants at the same
|
|||||||
time. Batteries are good example. So, batteries usually care if they're
|
time. Batteries are good example. So, batteries usually care if they're
|
||||||
externally powered or not.
|
externally powered or not.
|
||||||
|
|
||||||
For that case, power supply class implements notification mechanism for
|
For that case, the power supply class implements a notification mechanism for
|
||||||
batteries.
|
batteries.
|
||||||
|
|
||||||
External power supply (AC) lists supplicants (batteries) names in
|
An external power supply (AC) lists supplicants (batteries) names in
|
||||||
"supplied_to" struct member, and each power_supply_changed() call
|
"supplied_to" struct member, and each power_supply_changed() call
|
||||||
issued by external power supply will notify supplicants via
|
issued by an external power supply will notify supplicants via
|
||||||
external_power_changed callback.
|
the external_power_changed callback.
|
||||||
|
|
||||||
|
|
||||||
Devicetree battery characteristics
|
Devicetree battery characteristics
|
||||||
@@ -241,14 +241,14 @@ battery node have names corresponding to elements in enum power_supply_property,
|
|||||||
for naming consistency between sysfs attributes and battery node properties.
|
for naming consistency between sysfs attributes and battery node properties.
|
||||||
|
|
||||||
|
|
||||||
QA
|
Q&A
|
||||||
~~
|
~~~
|
||||||
|
|
||||||
Q:
|
Q:
|
||||||
Where is POWER_SUPPLY_PROP_XYZ attribute?
|
Where is POWER_SUPPLY_PROP_XYZ attribute?
|
||||||
A:
|
A:
|
||||||
If you cannot find attribute suitable for your driver needs, feel free
|
If you cannot find an attribute suitable for your driver needs, feel free
|
||||||
to add it and send patch along with your driver.
|
to add it and send a patch along with your driver.
|
||||||
|
|
||||||
The attributes available currently are the ones currently provided by the
|
The attributes available currently are the ones currently provided by the
|
||||||
drivers written.
|
drivers written.
|
||||||
@@ -258,18 +258,18 @@ A:
|
|||||||
|
|
||||||
|
|
||||||
Q:
|
Q:
|
||||||
I have some very specific attribute (e.g. battery color), should I add
|
I have some very specific attribute (e.g., battery color). Should I add
|
||||||
this attribute to standard ones?
|
this attribute to standard ones?
|
||||||
A:
|
A:
|
||||||
Most likely, no. Such attribute can be placed in the driver itself, if
|
Most likely, no. Such attribute can be placed in the driver itself, if
|
||||||
it is useful. Of course, if the attribute in question applicable to
|
it is useful. Of course, if the attribute in question is applicable to
|
||||||
large set of batteries, provided by many drivers, and/or comes from
|
a large set of batteries, provided by many drivers, and/or comes from
|
||||||
some general battery specification/standard, it may be a candidate to
|
some general battery specification/standard, it may be a candidate to
|
||||||
be added to the core attribute set.
|
be added to the core attribute set.
|
||||||
|
|
||||||
|
|
||||||
Q:
|
Q:
|
||||||
Suppose, my battery monitoring chip/firmware does not provides capacity
|
Suppose my battery monitoring chip/firmware does not provide capacity
|
||||||
in percents, but provides charge_{now,full,empty}. Should I calculate
|
in percents, but provides charge_{now,full,empty}. Should I calculate
|
||||||
percentage capacity manually, inside the driver, and register CAPACITY
|
percentage capacity manually, inside the driver, and register CAPACITY
|
||||||
attribute? The same question about time_to_empty/time_to_full.
|
attribute? The same question about time_to_empty/time_to_full.
|
||||||
@@ -278,11 +278,11 @@ A:
|
|||||||
directly measurable by the specific hardware available.
|
directly measurable by the specific hardware available.
|
||||||
|
|
||||||
Inferring not available properties using some heuristics or mathematical
|
Inferring not available properties using some heuristics or mathematical
|
||||||
model is not subject of work for a battery driver. Such functionality
|
model is not a subject of work for a battery driver. Such functionality
|
||||||
should be factored out, and in fact, apm_power, the driver to serve
|
should be factored out, and in fact, apm_power, the driver to serve
|
||||||
legacy APM API on top of power supply class, uses a simple heuristic of
|
legacy APM API on top of the power supply class, uses a simple heuristic of
|
||||||
approximating remaining battery capacity based on its charge, current,
|
approximating remaining battery capacity based on its charge, current,
|
||||||
voltage and so on. But full-fledged battery model is likely not subject
|
voltage and so on. But a full-fledged battery model is likely not a subject
|
||||||
for kernel at all, as it would require floating point calculation to deal
|
for the kernel at all, as it would require floating point calculations to
|
||||||
with things like differential equations and Kalman filters. This is
|
deal with things like differential equations and Kalman filters. This is
|
||||||
better be handled by batteryd/libbattery, yet to be written.
|
better be handled by batteryd/libbattery, yet to be written.
|
||||||
|
|||||||
Reference in New Issue
Block a user