On Fri, May 22, 2015 at 01:17:02PM +0100, Jon Hunter wrote: > > On 22/05/15 08:03, Linus Walleij wrote: > > On Thu, May 21, 2015 at 4:03 PM, Thierry Reding > > <thierry.reding@xxxxxxxxx> wrote: > > > >>>> I don't see any conceptual reason why the driver that binds to that node > >>>> can't register as both a pinctrl driver plus anything else it needs to. > > (...) > >>> Looking at it there should not be a problem here with regard to the > >>> driver_data member of the device struct and so I don't see why the > >>> tegra_dpaux_probe() could not call pinctrl_register() to register the > >>> device. > >> > >> Yes, I think that'd be the best solution. > > > > I'm pretty much ready to go to any compromises to get DRM/GPU > > drivers to use internal kernel subsystems. The tendency there > > is to reimplement all kernel driver frameworks and hammer registers > > they need to access. > > Thanks Linus, but after looking at this further I don't think this > approach will work after all. In order to call pinctrl_register() from > outside the pinctrl directory, also means exposing the pinctrl_dev and > pinctrl_desc structures and so this will get messy. Or at least a bigger > churn than I would have hoped for. It's not that much churn, is it? The structure definitions could be moved to include/linux/pinctrl/machine.h. That's included by core.h in drivers/pinctrl anyway, so that should really be all there is to it. > Thierry, what if we add a drivers/pinctrl/pinctrl-tegra-dpaux.c and then > simply call platform_device_register_data() from tegra_dpaux_probe() to > register the device? I could still use the parent of_node to match the > platform data for the dpaux pin controller. That'd work for me too. But if that's what it comes down to, I don't see a need to go through the driver model. Why not simply expose a simple set of functions to setup and tear down the pinctrl that the DPAUX driver can call? I'd still clearly prefer to have the pinctrl code live directly in the DPAUX driver, so I think we should at least give that a shot. Thierry
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