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;
- "#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
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.