On Mon, Sep 19, 2022 at 2:57 PM Martin Zaťovič <m.zatovic1@xxxxxxxxx> wrote: > 1. drivers/bus/wiegand.c > 2. include/linux/wiegand.h > 3. drivers/gpio/gpio-wiegand.h > > I have looked for drivers with a similar division and tried to figure out what the file drivers/bus/wiegand.c should contain. > So far I am only sure that it will contain the parity calculation functions. That is a question for people who know wiegand... Maybe just yourself! You also clearly need some bus infrastructure to populate and spawn devices. This mechanism depends on the specifics of the bus. > The code for sysfs attribute files may also be a part of this file, but I am not sure about it. > If hypothetically there was another Wiegand driver besides the GPIO one and a user would > like to connect both of these Wiegand interfaces, he would loose the ability to set attributes > for individual Wiegand interfaces, am I right? You should spawn individual devices on a wiegand bus (the kernel concept of bus). Each new device becomes something like a struct wiegand_device that contains a struct device, and the struct device is the anchor in sysfs. https://www.kernel.org/doc/html/latest/driver-api/driver-model/bus.html > Should the drivers/bus/wiegand.c be a full-scale driver or should it just be a file that > contains the Wiegand-specific functions(such as parity calculation)? It should be what we call a bus driver, OK a bit self-referential, but anything that is common for the bus and the code to spawn the devices. Yours, Linus Walleij
