On Wed, Oct 12, 2022 at 01:34:38PM -0700, Dmitry Torokhov wrote: > On Mon, Oct 10, 2022 at 10:36:00PM +0200, Linus Walleij wrote: > > On Thu, Oct 6, 2022 at 12:05 PM Daniel Thompson > > <daniel.thompson@xxxxxxxxxx> wrote: > > > On Thu, Oct 06, 2022 at 11:03:15AM +0200, Linus Walleij wrote: > > > > On Tue, Oct 4, 2022 at 10:35 PM Dmitry Torokhov > > > > <dmitry.torokhov@xxxxxxxxx> wrote: > > > > > > > > > > Dmitry, could you fix this? Just patch away in gpiolib-of.c. > > > > > > > > > > Sure, I'll add a few quirks. I wonder what is the best way to merge > > > > > this? I can create a bunch of IBs to be pulled, or I can send quirks to > > > > > you/Bartosz and once they land send the patches to drivers... > > > > > > > > When I did it I was sufficiently convinced that I was the only one patching > > > > the quirks in gpiolib-of.c that merge window so I just included it as > > > > a hunk in the driver patch. If there will be some more patches to that > > > > file I guess some separate patch(es) for gpiolib-of.c is needed, maybe > > > > an immutable branch for those if it becomes a lot. > > > > > > Are renames likely to be a common quirk on the road to libgpiod > > > conversion? > > > > > > I admit I sort of expected it to be common enough that there would be > > > one rename quirk in the code supported by an alphabetized string table. > > > Such a table would certainly still provoke troublesome merges but ones > > > that are trivially resolved. > > > > Dmitry added a table of sorts, the problems are usually a bit unique > > for each instance of nonstandard DT GPIO bindings, that's why I > > mostly solved it with open coding in gpiolib-of.c. > > OK, so I sent out the patch adding "reset-gpios" -> "gpios-reset" > translation quirk to keep compatibility with the legacy names, but > we still need to figure out what to do with incorrect line polarity > in current DTses in tree. Unlike with names we have no indication > if out of tree DTSes specify correct polarity or not, so we can't > reasonably come up with workarounds that are guaranteed to work for > everyone. I see several options: > > 1 the driver could continue ignoring line polarity specified in DTS > (and use gpiod_set_value_raw()) and hope that they all/will be > wired in the same way? > > 2 we could fix up in-kernel DTSes, allow flexibility of connection > in new designs and respect polarity specified in out of tree DTSes, > but accept that there can be breakages with old DTSes not contributed > to the mainline or DTSes that were "cached" from an older kernel > release > > 3 add another quirk forcing "active low" polarity for the legacy > "gpios-reset" name, which will allow us respecting polarity in > new "reset-gpios" name. I don't think they is any point in having a rename if legacy DTs break anyway! Thus if there is a rename then there should also be an active low quirk applied when the old name is used. Daniel.
