Hi Robert, On 02/08/2014 at 13:14:30 -0500, gmane@xxxxxxxxxxxxxxxxxxxxxxxxxxx wrote : > Hi, > > I would like to use a couple of resistors and keys and one Analog > input[1], read the analogue voltage from a kernel driver, figure out > which key is pressed and pass this on to the Linux input subsystem. > (Am I really the only one with this use case?) > > In my specific case it's about a beagle bone black, which means that > the A/D driver is an iio adc driver[2]. > > How would it be possible to reuse the iio A/D converter driver code > for my driver? Maybe it would even be possible to create something > more generic so iio A/D converter channels could be used as input > keys. Some sample code which would enable me to choose an analog > input and read from it from kernel space would help me to write some > basic sample driver, I guess. > > The reason I would like to write a device driver instead of a user > space application is mainly the input subsystem. From the user space > application's point of view utilizing a device driver which feeds > the input subsystem would make it easy to exchange what's underneath > without user space even noticing. (keys to Input pins, a key matrix > to I/O pins, i2c input, A/D converter,...). > Did you have a look at uinput? This would allow you to inject input events after processing the ADC values in userspace. Simple example: http://thiemonge.org/getting-started-with-uinput -- Alexandre Belloni, Free Electrons Embedded Linux, Kernel and Android engineering http://free-electrons.com -- To unsubscribe from this list: send the line "unsubscribe linux-iio" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
