You my want to consider using libgpiod with the /dev/gpiochipN character device. You can get and set multiple lines in one syscall.
The libgpiod tools are installed on the Debian image. More info: https://www.cnx-software.com/2017/11/03/learn-more-about-linuxs-new-gpio-user-space-subsystem-libgpiod/ On Fri, Mar 27, 2020, 09:30 Stephan Böck <boeckheim...@gmail.com> wrote: > Hello Robert, > > if I get this correctly, setting the direction of a gpio via the > corresponding register (e.g. let's say gpio4 base_addr + 0x134) should be > avoided? > > We use the BBB in combination with a carrier-board to have some industrial > in- and outputs. Therefore, some pins enable some flipflops during > initialization (the pins need to be outputs). These pins are later on used > as inputs. The current implementation manages all this with an assembly > program running on the pru and directly setting the right bits in the > different registers of the gpios. > Now, I want to port this to the BB AI. Since direct access causes trouble, > is there a better practise, than setting the direction/value of a gpio via > /sys/class/gpio? > > Regards, > Stephan > > > Am Donnerstag, 26. März 2020 15:26:56 UTC+1 schrieb RobertCNelson: >> >> On Thu, Mar 26, 2020 at 9:20 AM John Allwine <jo...@allwinedesigns.com> >> wrote: >> > >> > Is it possible to access the GPIO on the Beaglebone AI via /dev/mem >> similar to how it is done in this stackoverflow question on the Beaglebone >> Black? If so, how would I find what the offsets are? >> >> Hi John, >> >> dynamic changes to the am57xx's pinmux registers and gpio values is a bad >> idea.. >> >> Figure out what you need and set them up in the device tree. >> >> Regards, >> >> -- >> Robert Nelson >> https://rcn-ee.com/ >> > -- > For more options, visit http://beagleboard.org/discuss > --- > You received this message because you are subscribed to the Google Groups > "BeagleBoard" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to beagleboard+unsubscr...@googlegroups.com. > To view this discussion on the web visit > https://groups.google.com/d/msgid/beagleboard/2ee15690-0da0-4cc0-889b-6f3c8326c5aa%40googlegroups.com > <https://groups.google.com/d/msgid/beagleboard/2ee15690-0da0-4cc0-889b-6f3c8326c5aa%40googlegroups.com?utm_medium=email&utm_source=footer> > . > -- For more options, visit http://beagleboard.org/discuss --- You received this message because you are subscribed to the Google Groups "BeagleBoard" group. To unsubscribe from this group and stop receiving emails from it, send an email to beagleboard+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/beagleboard/CAEf4M_DgSg%3Dse0LCpsB%2BzV5sAq4-SphR6tNKiECd29jqOFwAOw%40mail.gmail.com.
