Hi Michael, Sorry for the slow response to this email, I'm fighting with our IT on an email filtering system that is not delivering linux-iio emails to me. > -----Original Message----- > From: Michael Welling [mailto:mwelling79@xxxxxxxxx] On Behalf > Of Michael Welling > Sent: Tuesday, May 12, 2015 6:12 PM > To: Greg Wilson-Lindberg > Cc: linux-iio@xxxxxxxxxxxxxxx > Subject: Re: BBB touch screen and ADC interactions > > On Tue, May 12, 2015 at 04:23:43PM -0700, Greg Wilson-Lindberg wrote: > > Hello all, > > I've got a problem with the BeagleBone Black ti_am335x_tsc, > ti_am335x_adc & ti_am335x_tsadc drivers, and Jonathan Cameron > suggested that I reach out to this list to see if any one > here has any insight to my problem. > > > > I'm using a BBB running a Debian Jessie build with the > 3.14.40 ti kernel by Robert C. Nelson. I've got it hooked up > to a touch screen and I would like to also be able to use > some of the remaining adc channels. > > > > As soon as I try to read any of the remaining channels the > touch screen locks up. I've tried catting them from > /sys/bus/iio/devices/iio:device0/in_voltageX_raw, using the > generic_buffer program provided by the kernel, and using the > Analog Devices libiio library. In all cases, I get the same > results, adc values that look reasonable, but the touch > screen stops responding. > > > > Does the touchscreen freeze indefinitely or does it come back > after ADC sampling is stopped? It is freezing indefinitely. > > > I've asked on the TI support forum if they could help with > this problem, but their response was that they only supported > the TI SDK. > > > > Can any of you tell me if the current iio subsystem will > work correctly with the ti touch screen and adc drivers? > > > > I have been working on porting Linux to a device that uses > the AM335x and have noticed that the drivers has undergone > many changes recently. I am now using a 4.0 kernel and am > able to sample the ADC and use the touchscreen simultaneously. > > When sampling the ADC you will notice that the touchscreen is > less responsive but it does not freeze. The responsiveness > comes back when ADC sampling stops. > > One thing that I have noticed recently is that when using > ts_calibrate or ts_test the screen will register touch > releases repeatedly without touching the screen. > > I have a workaround patch but have not attempted to push it > upstream yet. > > So it won't freeze the touchscreen completely after sampling > ADCs but you still may notice some quirks. > > The best way to find out is building the new kernel and trying it out. I'll try out a new (4.0 - 4.1) kernel, but we are using QT to generate a GUI and I don't know if the graphics that we need have been ported to the mainline yet. I guess I'll find out the hard way. Thanks for the information, Greg > > > Greg Wilson-Lindberg > > Sakura Finetek > > 310-783-5075 > > -- > > 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 > > -- 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
