On Wed, Jun 17, 2020 at 02:35:28PM +0200, Martin Kaiser wrote: > Hello Greg and all, > > Thus wrote Greg KH (greg@xxxxxxxxx): > > > Please do not do that. There are valid kernel apis to grant access to > > registers easily, > > the most simple case would be a "reset reason" register within the > chip's address space. A hand-crafted driver would ioremap the region and > implement a sysfs show method that reads the register. No, that's not what sysfs is for. You would export this in the proper way that "reset reason" expects. > What do you recommend for providing read access to such a register > via sysfs? Is this a job for the userspace I/O (UIO) subsystem? If all you want is direct memory access to userspace for stuff like this, what's wrong with /dev/mem ? If you want access to memory and interrupts to do it all in userspace, then yes, that's what UIO is for, use that please. thanks, greg k-h _______________________________________________ Kernelnewbies mailing list Kernelnewbies@xxxxxxxxxxxxxxxxx https://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
