GitLab

The AXP288's recommended and factory default Vhold value (minimum
input voltage below which the input current draw will be reduced)
is 4.4V. This lines up with other charger IC's such as the TI
bq2419x/bq2429x series which use 4.36V or 4.44V.

For some reason some BIOS-es initialize Vhold to 4.6V or even 4.7V
which combined with the typical voltage drop over typically low
wire gauge micro-USB cables leads to the input-current getting
capped below 1A (with a 2A capable dedicated charger) based on Vhold.

This leads to slow charging, or even to the device slowly discharging
if the device is in heavy use.

As the Linux AXP288 drivers use the builtin BC1.2 charger detection
and send the input-current-limit according to the detected charger
there really is no reason not to use the recommended 4.4V Vhold.

Set Vhold to 4.4V to fix the slow charging issue on various devices.

There is one exception, the special-case of the HP X2 2-in-1s which
combine this BC1.2 capable PMIC with a Type-C port and a 5V/3A factory
provided charger with a Type-C plug which does not do BC1.2. These
have their input-current-limit hardcoded to 3A (like under Windows)
and use a higher Vhold on purpose to limit the current when used
with other chargers. To avoid touching Vhold on these HP X2 laptops
the code setting Vhold is added to an else branch of the if checking
for these models.

Note this also fixes the sofar unused VBUS_ISPOUT_VHOLD_SET_MASK
define, which was wrong.
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>