The interface is proprietary and only a few know bits are implemented. Have a look at the thinkpad_acpi kernel module or vendor ACPI code for additional bits.

Some basic fan and power management functionality is implemented.
Without a datasheet (by Lenovo) for every EC generation it's impossible to tell what needs to be implemented.

Regards,
Patrick

Martin Kepplinger <martink@posteo.de> schrieb am Do., 14. März 2019, 14:23:
Am 14.03.2019 11:46 schrieb Nico Huber:
> Hi Martin,
>
> Am 14.03.19 um 10:19 schrieb Martin Kepplinger:
>> So, I'm looking into h8 EC access.
>>
>> Where does ec_set_bit(0x3a, 0) for audio-mute or ec_set_bit(0x3a, 6)
>> for wwan-enable
>> come from (let's keep that as an example)?
>
> this uses a software interface that is defined by the program that runs
> on the EC, aka the EC firmware. The EC firmware exposes an address
> space
> (usually up to 256B) for communication with the host firmware (e.g.
> coreboot). Usually, there is *no* relation to hardware registers.
>

Ok. Patrick, do you have any more details on the interface here, and
what is
or isn't implemented in coreboot?

thanks

                                         martin