* How to inject fwnode/oftree/acpi data by platform driver ? @ 2019-06-01 14:14 Enrico Weigelt, metux IT consult 2019-06-11 18:44 ` Andy Shevchenko 0 siblings, 1 reply; 3+ messages in thread From: Enrico Weigelt, metux IT consult @ 2019-06-01 14:14 UTC (permalink / raw) To: LKML, linux-acpi, devicetree, Platform Driver Hi folks, I'm looking for a way to inject fwnode data from a platform driver, in order to initialize generic drivers w/ board specific configuration. The idea is getting rid of passing driver specific pdata structs (which, IIRC, seem to be deprecated). An example usecase is the APUv2/3 board, which have things like gpios wired to buttons and LEDs. The board can only be detected via DMI string, no way to probe the platform devices - have to be initialized explicitly (that's how I'm already doing it now). The nicest way, IMHO, would be if I could just write some piece of DTS and some fancy magic all the rest under the hood. Such thing doesn't seem to exist yet. Does it make sense to implement that ? How could we do it ? Which other options do we have ? Or should we just leave everything as it is and stick w/ pdata structs ? thx --mtx -- Enrico Weigelt, metux IT consult Free software and Linux embedded engineering info@metux.net -- +49-151-27565287 ^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: How to inject fwnode/oftree/acpi data by platform driver ? 2019-06-01 14:14 How to inject fwnode/oftree/acpi data by platform driver ? Enrico Weigelt, metux IT consult @ 2019-06-11 18:44 ` Andy Shevchenko 2019-06-12 8:01 ` Heikki Krogerus 0 siblings, 1 reply; 3+ messages in thread From: Andy Shevchenko @ 2019-06-11 18:44 UTC (permalink / raw) To: Enrico Weigelt, metux IT consult, Krogerus, Heikki Cc: LKML, ACPI Devel Maling List, devicetree, Platform Driver +Cc: Heikki. Heikki, can you help here with swnodes? On Sat, Jun 1, 2019 at 5:17 PM Enrico Weigelt, metux IT consult <lkml@metux.net> wrote: > > Hi folks, > > > I'm looking for a way to inject fwnode data from a platform driver, > in order to initialize generic drivers w/ board specific configuration. > The idea is getting rid of passing driver specific pdata structs > (which, IIRC, seem to be deprecated). > > An example usecase is the APUv2/3 board, which have things like gpios > wired to buttons and LEDs. The board can only be detected via DMI > string, no way to probe the platform devices - have to be initialized > explicitly (that's how I'm already doing it now). > > The nicest way, IMHO, would be if I could just write some piece of DTS > and some fancy magic all the rest under the hood. Such thing doesn't > seem to exist yet. Does it make sense to implement that ? How could > we do it ? > > Which other options do we have ? > > Or should we just leave everything as it is and stick w/ pdata structs ? > > > thx > --mtx > > -- > Enrico Weigelt, metux IT consult > Free software and Linux embedded engineering > info@metux.net -- +49-151-27565287 -- With Best Regards, Andy Shevchenko ^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: How to inject fwnode/oftree/acpi data by platform driver ? 2019-06-11 18:44 ` Andy Shevchenko @ 2019-06-12 8:01 ` Heikki Krogerus 0 siblings, 0 replies; 3+ messages in thread From: Heikki Krogerus @ 2019-06-12 8:01 UTC (permalink / raw) To: Andy Shevchenko, Enrico Weigelt, metux IT consult Cc: LKML, ACPI Devel Maling List, devicetree, Platform Driver Hi, On Tue, Jun 11, 2019 at 09:44:23PM +0300, Andy Shevchenko wrote: > +Cc: Heikki. > Heikki, can you help here with swnodes? > > On Sat, Jun 1, 2019 at 5:17 PM Enrico Weigelt, metux IT consult > <lkml@metux.net> wrote: > > > > Hi folks, > > > > > > I'm looking for a way to inject fwnode data from a platform driver, > > in order to initialize generic drivers w/ board specific configuration. > > The idea is getting rid of passing driver specific pdata structs > > (which, IIRC, seem to be deprecated). > > > > An example usecase is the APUv2/3 board, which have things like gpios > > wired to buttons and LEDs. The board can only be detected via DMI > > string, no way to probe the platform devices - have to be initialized > > explicitly (that's how I'm already doing it now). > > > > The nicest way, IMHO, would be if I could just write some piece of DTS > > and some fancy magic all the rest under the hood. Such thing doesn't > > seem to exist yet. Does it make sense to implement that ? How could > > we do it ? > > > > Which other options do we have ? > > > > Or should we just leave everything as it is and stick w/ pdata structs ? The software nodes (drivers/base/swnode.c) were designed to supply fwnodes that describe devices in the same way DT does. The goal I had with the software nodes was exaclty to get rid of pdata, so they do sound like the thing you are looking for. If you check Rafael's latest linux-next branch [1], drivers/platform/x86/intel_cht_int33fe.c can be used as an example how to use the software nodes. I think it's time to add documentation for the software nodes to the kernel, but I'll list here the features the software nodes have: - The software nodes are created independently from device entries. - Software nodes support hierarchy. Every software node has a pointer to a parent software node. - Software nodes can have device properties. - Software nodes can have reference pointers to other software nodes (outside of the hierarchy). Creating the software nodes from static description (struct software_node - available from Linux kernel v5.3 onwards) is straightforward. Once you have them, when you create your device entries (struct device), you can associate a software node with a device just like like any other fwnode: device_initialize(&my_dev); my_dev.parent = parent; my_dev.fwnode = software_node_fwnode(&my_node); ... device_add(&my_device); After that, you can access all the information the software nodes supply to the device by using fwnode_* APIs from your driver, just like with ACPI or DT. Basically the entire fwnode_* API is now supported with softwarw nodes, except the device graph (fwnode_graph*) API. One final note. The hardware description must always primarily come from the system firmware. You only use software nodes if it's too late to influence what goes to the ACPI tables, or if using DTS is not an option. [1] https://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm.git/log/?h=linux-next thanks, -- heikki ^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2019-06-12 8:01 UTC | newest] Thread overview: 3+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2019-06-01 14:14 How to inject fwnode/oftree/acpi data by platform driver ? Enrico Weigelt, metux IT consult 2019-06-11 18:44 ` Andy Shevchenko 2019-06-12 8:01 ` Heikki Krogerus
This is a public inbox, see mirroring instructions for how to clone and mirror all data and code used for this inbox; as well as URLs for NNTP newsgroup(s).