Le Thu, 24 Mar 2022 11:08:15 +0100, Philipp Zabel <p.zabel@xxxxxxxxxxxxxx> a écrit : > > - It can be used as a PCIe endpoint, connected to a separate platform > > that acts as the PCIe root complex. In this case, all the devices > > that are embedded on this SoC are exposed through PCIe BARs and the > > ARM64 cores of the SoC are not used. Since this is a PCIe card, it > > can be plugged on any platform, of any architecture supporting PCIe. > > > > Appart from adding software node support, the fwnode API would also > > allow to add ACPI support more easily later. > > Thank you for the explanation. So this would be used by the sparx5 > switch reset driver to provide the microchip,lan966x-switch-reset > controller via software node? Exactly. > > If that needs to be converted to fwnode anyway, it would be nice to > include the conversion in this series as an example. Yes indeed, the sparx5 driver was modified in my private tree. I will change it to use fwnode. > > [...] > > On that side, I must say I'm not really competent regarding ACPI > > which I do not know enough to answer you on that point. > > > > The discussions we had with Mark Brown regarding fwnode ACPI support > > pointed out the fact that we should not create unwanted ACPI support > > by using the same descriptions/specifications that exists for the > > device-tree. In order to avoid that, we suggested to explicitely left > > out ACPI with this fwnode support. This will allow to specify that > > support later and integrate it in the subsystem that have been > > converted to fwnode. > > Ok. > > > > > > > On the other hand, I think it would be good to avoid the direct of_node > > > assignment, possibly by letting devm_reset_controller_register() > > > initialize of_node or fwnode from the device for most cases, and by > > > adding of_reset_controller_register() and > > > fwnode_reset_controller_register() variants that take the node as an > > > argument for the rest. > > > That could allow to eventually get rid of the of_node pointer. > > > > Ok, I see that. Do you want this to be done in this series ? > > Just thinking out loudly, before starting to drop the > rcdev->of_node assigment from drivers en masse, I'd like to use the > opportunity and turn reset_controller_register() and friends into > macros that provide the module owner as a parameter, so the explicit > rcdev->owner = THIS_MODULE assignment can be removed from the drivers > as well. Indeed, that seems like a good thing to do, direct assignments are often a pain to change all other the place. BTW, once drivers are converted to avoid direct assignment of the of_node field, it will be removable, the fwnode field will be sufficient for all operations. Thanks, Clément -- Clément Léger, Embedded Linux and Kernel engineer at Bootlin https://bootlin.com
