Re: [PATCH 0/2] extcon: Intel Cherry Trail Whiskey Cove PMIC and external charger tweaks

From: Hans de Goede
Date: Wed Feb 13 2019 - 18:00:51 EST


Hi,

On 10-02-19 21:36, Yauhen Kharuzhy wrote:
At implementation of charging support for Lenovo Yoga Book (Intel Cherry Trail
based with Whiskey Cove PMIC), two pitfalls were found:

- for detection of charger type by PMIC, bit 6 in the CHGRCTRL1 register
should be set in 0 (and set to 1 for Host mode). Pick up its definition
and logic from from Intel code drop[1];

- "#CHARGE ENABLE" signal of external charger (bq25892) in Yoga Book is
connected to one of PMIC outputs controlled by CHGDISCTRL register.
Enable charging at driver initialization. Pick up this from Lenovo's code
drop[2,3].

Please keep in mind that I have no docs for Whiskey Cove PMIC, so this patches
are based on some kind of reverse engineering and suppositions, correct me if
this semantic is wrong for common case.

[1]. https://github.com/01org/ProductionKernelQuilts/uefi/cht-m1stable/patches/0001-power_supply-intel-pmic-ccsm-driver.patch
[2]. https://github.com/jekhor/yogabook-linux-android-kernel/blob/b7aa015ab794b516da7b6cb76e5e2d427e3b8b0c/drivers/power/bq2589x_charger.c#L2257
[3]. https://github.com/01org/ProductionKernelQuilts/uefi/cht-m1stable/patches/EM-Charger-Disable-battery-charging-in-S3-and-enable.patch

Thank you for these patches, besides your Lenovo Yoga Book I'm aware of
only 2 other device models using the CHT Whiskey Cove PMIC, the GPD win
and GPD pocket devices. These both work fine without the changes your
patches introduce.

I need to check if your changes do not cause regressions on these 2
devices, which are used with Linux by quite a few people. I will try
to make some time for testing this sometime next week.

A kind request to the platform-x86 driver maintainers (hi Andy): Please
do not apply these patches until I've been able to test they don't cause
issues elsewhere.

Regards,

Hans