Add sysfs entry for system load control

During discussions of the development of a new driver [1], it was concluded that a new sysfs ABI for controlling the connection from power to system load is wanted. This patchset introduces this.

There are already several drivers that are controlling this, but with their own custom sysfs entries. The drivers in this patchset were find with a simple grep for bat\s?fet (there might be more?), and then converted to use this new sysfs ABI. The old custom ABIs are left untouched of course, for backward compatibility.

[1] https://lore.kernel.org/lkml/[email protected]/

Changes in v2:

* Drop already merged patches (picked up by Sebastian in v1).
* Pack struct power_supply_desc so that an extra member doesn't increase the size unnecessarily too much.
* Use power_supply_show_enum_with_available() for POWER_SUPPLY_LOAD_SWITCH.
* Drop commit for selftest since properties using power_supply_show_enum_with_available() don't have any helper test functions. Should we add this (in a separate patch set)? I'll others decide if it's worth the churn...
* Add implementation for bq25630.

Link to v1: https://lore.kernel.org/lkml/[email protected]/

Waqar Hameed (8):
power: supply: Pack power_supply_desc to eliminate holes
power: supply: Add sysfs entry for system load control
power: supply: ltc4162-l: Use POWER_SUPPLY_PROP_LOAD_SWITCH
power: supply: rt9471: Use POWER_SUPPLY_PROP_LOAD_SWITCH
power: supply: rt9467: Use POWER_SUPPLY_PROP_LOAD_SWITCH
power: supply: bq24257: Use POWER_SUPPLY_PROP_LOAD_SWITCH
power: supply: bq24190: Use POWER_SUPPLY_PROP_LOAD_SWITCH
power: supply: bq25630: Add support for BATFET control

 Documentation/ABI/testing/sysfs-class-power   | 25 ++++++
 .../ABI/testing/sysfs-class-power-ltc4162l    |  2 +
 .../ABI/testing/sysfs-class-power-rt9467      |  2 +
 .../ABI/testing/sysfs-class-power-rt9471      |  2 +
 drivers/power/supply/bq24190_charger.c        | 62 ++++++++++++++
 drivers/power/supply/bq24257_charger.c        | 43 +++++++++-
 drivers/power/supply/bq25630_charger.c        | 84 +++++++++++++++++++
 drivers/power/supply/ltc4162-l-charger.c      | 56 +++++++++++--
 drivers/power/supply/power_supply_sysfs.c     | 17 ++++
 drivers/power/supply/rt9467-charger.c         | 54 ++++++++++--
 drivers/power/supply/rt9471.c                 | 54 ++++++++++--
 include/linux/power_supply.h                  | 18 +++-
 12 files changed, 397 insertions(+), 22 deletions(-)

base-commit: 73e3f0710014fe6d4ed98cfc02292f6121db7558

2.43.0