On Thu, Dec 02, 2021 at 06:00:05PM +0100, Bartosz Golaszewski wrote: > On Thu, Dec 2, 2021 at 4:41 PM Andy Shevchenko > <andriy.shevchenko@xxxxxxxxxxxxxxx> wrote: > > On Thu, Dec 02, 2021 at 02:52:55PM +0100, Bartosz Golaszewski wrote: > > > On Thu, Dec 2, 2021 at 2:45 PM Andy Shevchenko > > > <andriy.shevchenko@xxxxxxxxxxxxxxx> wrote: > > > > On Thu, Dec 02, 2021 at 02:06:57PM +0100, Bartosz Golaszewski wrote: > > > > > On Thu, Dec 2, 2021 at 12:38 PM Andy Shevchenko > > > > > <andriy.shevchenko@xxxxxxxxxxxxxxx> wrote: > > > > > > On Thu, Dec 02, 2021 at 01:35:01PM +0200, Andy Shevchenko wrote: > > > > > > > On Thu, Dec 02, 2021 at 12:24:06PM +0100, Bartosz Golaszewski wrote: > > > > > > > > On Thu, Dec 2, 2021 at 11:58 AM Andy Shevchenko > > > > > > > > <andriy.shevchenko@xxxxxxxxxxxxxxx> wrote: > > > > > > > > > On Wed, Dec 01, 2021 at 02:11:28PM +0100, Bartosz Golaszewski wrote: > > > > > > > > > > On Tue, Nov 30, 2021 at 10:04 PM Bartosz Golaszewski <brgl@xxxxxxxx> wrote: > > > > > > > > > > > > > > > > > > ... > > > > > > > > > > > > > > > > > > > Let me maybe rephrase the problem: currently, for GPIO devices > > > > > > > > > > instantiating multiple banks created outside of the OF or ACPI > > > > > > > > > > frameworks (e.g. instantiated manually and configured using a > > > > > > > > > > hierarchy of software nodes with a single parent swnode and a number > > > > > > > > > > of child swnodes representing the children), it is impossible to > > > > > > > > > > assign firmware nodes other than the one representing the top GPIO > > > > > > > > > > device to the gpiochip child devices. > > > > > > > > > > > > > > > > > > > > In fact if we want to drop the OF APIs entirely from gpiolib - this > > > > > > > > > > would be the right first step as for gpio-sim it actually replaces the > > > > > > > > > > gc->of_node = some_of_node; assignment that OF-based drivers do for > > > > > > > > > > sub-nodes defining banks and it does work with device-tree (I verified > > > > > > > > > > that too) thanks to the fwnode abstraction layer. > > > > > > > > > > > > > > > > > > In exchange of acknowledgements I confirm that I understood the issue > > > > > > > > > you are describing. What I still don't like is this band-aid:ish approach. > > > > > > > > > What we really need is to replace of_node by fwnode in GPIO library once > > > > > > > > > for all. But it can be done later after your simulation series (or before, > > > > > > > > > i.o.w. independently), hence I propose to update TODO and do it separately. > > > > > > > > > > > > > > > > > > > > > > > > > But this is what we already do for OF. How would the core gpiolib know > > > > > > > > how the firmware nodes represent the banks? It's the driver's job to > > > > > > > > tell the framework which node corresponds with what. If anything, we > > > > > > > > should start replacing of_nodes with fwnodes in drivers and eventually > > > > > > > > we'd drop the of_node pointer from gpio_chip entirely, but we'd keep > > > > > > > > the fwnode pointer I added as the driver still needs to assign it > > > > > > > > itself. > > > > > > > > > > > > > > > > Again: I may be missing something here but I've been going through > > > > > > > > this on and on and can't figure out any other way. Looking at > > > > > > > > gpiolib-acpi.c I don't see it correctly assigning fwnodes to > > > > > > > > sub-devices either but I don't have any HW to test it. > > > > > > > > > > > > > > > > As for this series: I can't really drop this patch as gpio-sim relies > > > > > > > > on swnodes being correctly associated with gpio_chips to identify the > > > > > > > > gpiodevs from configfs callbacks. > > > > > > > > > > > > > > Then we need to replace of_node by fwnode as a first step. I have looked > > > > > > > briefly into the list of drivers that may have been cleaned up and it doesn't > > > > > > > look too long. > > > > > > > > > > > > Let me kick this off by sending couple of patches. > > > > > > > > > > Are you fine with merging this in the meantime to get gpio-sim into mainline? > > > > > > > > gpio-sim, yes, (though I may bikeshed about naming of the configfs attributes, > > > > etc) but not this patch. > > > > > > > > > > There's no way around it though AFAIK. First - the 'gpio-line-names' > > > property will not work for banks. 'ngpios' will only work because we > > > read it manually in probe() to figure out the number of sysfs groups. > > > And also configfs callbacks will not be able to associate bank devices > > > with configfs groups. I would really like to hear an alternative - > > > even if it's just an idea and not actual implementation. > > > > > > I'm really curious to see how you'll remove the of_node pointer and > > > not introduce the corresponding fwnode pointer actually. > > > > Seems I was unclear, fwnode pointer will be needed, but what I'm against of is > > having of_node and fwnode at the same time in the struct gpio_chip. > > > > Yes, we may modify this patch to work without that ugly ifdeffery and with both > > in the structure, but I don't think it's a good solution. > > > > It may not be the best solution but we can't simply convert all the > drivers to fwnode and pray they work. I would like every converted > driver to be well tested because there can be some issues lurking in > the fwnode <-> of_node conversion. That will take time. > Meanwhile, this would block gpio-sim for months again. I don't believe > this patch is wrong as it fixes a real issue and as you said: fwnode > will most likely stay in gpio_chip.o It doesn't strictly speaking "fix". But it allows to get things right. > IMO we should introduce fwnode, convert gpiolib and drivers to using > it gradually, remove of_node once there are no more users. I may accept the change after some amendments done: - get rid of ifdeffery (remove that block completely) - add TODO entry - add "deprecated" keyword to of_node - ...I hope I haven't miss anything else... > > Now clearly we have to clean up of_node first. -- With Best Regards, Andy Shevchenko
