On Wed, Sep 30, 2020 at 12:04:43PM +0000, Flavio Suligoi wrote: > > > > > > I was wondering if there is a generic GPIO driver that I can use > > Maybe I was not so clear, but as Bart mentioned the least you can do > > is simply define line name via "gpio-line-names" property. The problem > > here is when and how you would like to have them incorporated. > > I already tried adding the "gpio-line-names" property, but the problem > is the same: no driver asks for this GPIO, as shown by the following > kernel messages: > > ACPI: Host-directed Dynamic ACPI Table Load: > ACPI: SSDT 0xFFFF994034D42A00 0000E8 (v05 ASEMsp GPIO_BTN 00000001 INTL 20200717) > ACPI: \_SB_.GPO1.BTNS: PRP0001 requires 'compatible' property > So I'll start to write a simple device driver to use this GPIO. > I'll keep you informed! > > > When: if ACPI tables are being provided by firmware which you may not > > alter, then you must use initramfs type of solution (no configfs, > > don't know about EFI var though). How: In that case you might have a > > chance to incorporate _DSD() method into *existing* _CRS() one. > > Possible impediments: if ACPI table from firmware already has a _DSD() > > defined or above is not working for some reason. In such a case you > > must upgrade entire DSDT via initramfs. > > > > > > > Adding Andy who knows ACPI GPIO well. > > > > > > > > Thanks. > > > > > > > > > In general, the "gpio-line-names" property is used for that and it's > > > > > supported both for device tree as well as ACPI, although I have only > > > > > ever used the former. > > > > > > > > Right. ACPI supports properties via _DSD() method. I guess you simply didn't get. The "gpio-line-names" property of GPIO *controller* (provider!) and you are trying to do something with the *consumer* if I got it right. And of course GPIO line, which has name, has no difference in use from another w/o name assigned. You will need to request it by *consumer* either in kernel or in user space. To be more precise we have to look at your DSDT. -- With Best Regards, Andy Shevchenko
