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.