Hello Einar, On Fri, Oct 12, 2018 at 08:02:09AM +0000, Einar Vading wrote: > Since I was just evaluating the mockup driver to use in a test setup > I'll give my 2 cents. very welcome, thanks. > The benefit of the simulator is that we get the possibility to, if I > understand correctly, monitor an input for changes on the connected > output. Sure, we could also use ftrace but I like the idea of having > the two connected GPIOs. As a matter of fact I was just thinking about > implementing something that gave the same functionality for the mockup > driver. > > What I like from the mockup driver is the possibility to have *many* > gpios on the same chip. We currently have a MCU I/O expander that > gives us 110+ gpios. So for us 64 GPIOs is really not enough. Currently several states are stored in an u32 where each bit corresponds to a GPIO which simplifies some operations. Probably an array of unsigned long could be used, which would have the benefit that set_bit et al would work. Then we either need a compile time limit, a variadic driver data struct or one additional allocation for each variable that is an u32 currently. Would it help to instanciate more than one gpio-simulator? Best regards Uwe -- Pengutronix e.K. | Uwe Kleine-König | Industrial Linux Solutions | http://www.pengutronix.de/ |
