Am Thu, 10 Jun 2021 13:14:49 +0300 schrieb Andy Shevchenko <andy.shevchenko@xxxxxxxxx>: > On Thu, Jun 10, 2021 at 12:14 PM Henning Schild > <henning.schild@xxxxxxxxxxx> wrote: > > > > Am Mon, 8 Mar 2021 14:20:13 +0200 > > schrieb Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>: > > > > > There are a few users and even at least one more is coming > > > that would like to utilize p2sb mechanisms like hide/unhide > > > a device from PCI configuration space. > > > > > > Here is the series to deduplicate existing users and provide > > > a generic way for new comers. > > > > > > It also includes a patch to enable GPIO controllers on Apollo Lake > > > when it's used with ABL bootloader w/o ACPI support. > > > > That bit is especially interesting. Making pinctl*lake initialize > > when ACPI IDs are missing and p2sb is hidden. > > > > However i have seen pinctl-broxton get confused because it was > > trying to come up twice on a system that has the ACPI entries. Once > > as "INT3452" and second as "apollolake-pinctrl". They should > > probably mutually exclude each other. And the two different names > > for "the same"? thing make it impossible to write a driver using > > those GPIOs. > > Then it's clearly told that BIOS provides confusing data, it exposes > the ACPI device and hides it in p2sb, how is it even supposed to work? The patchset works fine on a machine with hidden p2sb and no ACPI, except for the NULL pointer issue i sent that patch for. The problem appeared with the patchset being used on a machine having ACPI entries and a visible p2sb. > I consider only these are valid: > - ACPI device is provided and it's enabled (status = 15) => work with > ACPI enumeration > - no ACPI device provided and it's hidden or not by p2sb => work via > board file > - no ACPI device provided and no device needed / present => no > driver is needed > > > Unless it would try and look up both variants or not looking up with > > gpiochip.label. > > > > I would also need that "enable GPIO w/o ACPI" for skylake. > > Not a problem to add a platform driver name there or actually for all > of the Intel pin control drivers (depends what suits better to the > current design). > > > I think it > > would be generally useful if the GPIO controllers would be enabled > > not depending on ACPI, and coming up with only one "label" to build > > on top. > > I didn't get what 'label' means here... The name of the gpiochip /sys/class/gpiochipxxx/label or the first arg to GPIO_LOOKUP_IDX It seems to me that the very same device driver can come up as "apollolake-pinctrl.0" or "INT3452.0" depending on ACPI table entries. Henning > > > Please, comment on the approach and individual patches. > > > > > > (Since it's cross subsystem, the PCI seems like a main one and > > > I think it makes sense to route it thru it with immutable tag > > > or branch provided for the others). > >
