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@linux.intel.com 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@linux.intel.com 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@linux.intel.com 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@linux.intel.com 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@bgdev.pl 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.