On Wednesday 13 February 2013 at 13:51:12, Linus Walleij wrote: > On Wed, Feb 13, 2013 at 12:13 PM, Lars Poeschel <poeschel@xxxxxxxxxxx> wrote: > > On Monday 11 February 2013 at 22:25:51, Grant Likely wrote: > >> However, is the pullup selection per-gpio line? If so, then why not > >> encode it into the flags field of the gpio specifier? > > > > Yes, the pullup is per-gpio line. I am working on that. It turns out, > > that this is a bit difficult for me, as there is no real documentation > > and no other driver is doing it or something similar yet. Exception are > > very few gpio soc drivers where situation is a bit different. They seem > > to rely an fixed global gpio numbers and they are always memory mapped. > > But as I said I am working on it... > > Part of your problem is that pull-up is pin control territory. > > We invented that subsystem for a reason, and that reason > was that the GPIO subsystem had a hard time accomodating > things like this. > > If you look in drivers/pinctrl/pinctrl-abx500.c which is my > latest submitted pinctrl driver you can see that this is basically > a quite simple GPIO chip, we just model it as a pin controller > with a GPIO front-end too exactly because it can do things > like multiplexing, pull-up and pull-down. > > Have you considered this approach? No, I haven't. And although this doesn't solve all my problems, I like the idea very much! Thank you for this! But at the moment it looks to me that this could be a bit overkill for setting this single register and I don't think this is, what Grant meant me to do. Anyway, I will have a deeper look at this. Thanks, Lars -- To unsubscribe from this list: send the line "unsubscribe linux-doc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
