On Thu, Mar 14, 2019 at 04:17:13PM +0530, Jay Aurabind wrote: > On Wed, 13 Mar 2019 at 19:55, Greg KH <greg@xxxxxxxxx> wrote: > > > > On Wed, Mar 13, 2019 at 12:02:02PM +0530, Jay Aurabind wrote: > > > Hi, > > > > > > Before I send this patch to actual mailing list, I'd appreciate if > > > someone could tell me if this is a bad idea! > > > > > > The driver in staging for pi433 (a wireless transceiver) uses IOCTLs > > > at the moment. I wish to add a sysfs interface to it that control the > > > various transmission and reception parameters. In the ioctl interface, > > > it uses two structs that have about 40 parameters in total. > > > > > > For the corresponding sysfs interface, since there are a lot of > > > parameters, would it be justified to use the same binary format though > > > sysfs_create_binary_file() ? The rationale is that it would be easier > > > to simply pack all the config options in the struct and send it in > > > once rather than individually write 40 files. This is what the > > > attached patch follows. Interface is added only for reception > > > parameters as of now. > > > > binary sysfs files are only allowed for "pass through" data, where the > > kernel does not touch the information at all and only passes it from the > > hardware, to userspace directly (or the other way around). It can not > > be used for data that the kernel actually knows about and modifies / > > acts on. > > > > An example of valid binary sysfs files are USB and PCI device > > configuration information (read directly from the hardware), or firmware > > files that are send from userspace directly to the hardware without the > > kernel knowing what the data is. > > > > You can't use a binary sysfs file for ioctl-like data, that's not > > allowed, just use an ioctl for that. Or better yet, use a common api > > interface for it, to match the other types of devices. > > Thank you for the explanation. What API would the most appropriate for > such a wireless transceiver ? If I could make it as a networking > driver, I could probably use setsockopt to pass in these > configuration. Is this recommended ? No, try looking at how v4l2 works, odds are they already have the correct api for this type of device there for you to use. thanks, greg k-h _______________________________________________ Kernelnewbies mailing list Kernelnewbies@xxxxxxxxxxxxxxxxx https://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
