Hi Florian, On 11/10/2015 08:02 AM, [email protected] wrote: > I'm currently using the latest Debian Jessie image (2015-11-08) on my > Beaglebone Black. > I want to use UART4 as RS485 interface and use gpio3_19 as DE/RE signal. > > The device tree overlay which I use to configure the pinmux settings can be > found here: > https://github.com/Sillern/BB-RS485/blob/master/BB-RS485-00A0.dts > > When I load this overlay and try to configure the port in my C program, I > always get the error message "inappropriate ioctl for device" > when using the command > ioctl( fd, TIOCSRS485, &rs485conf ) > where rs485conf is a struct serial_rs485 > > The image uses kernel version 4.1.12-ti-r28. Has this kernel version RS485 > support enabled for the UART interfaces? > If not, is there a kernel version (preferable 4.1.X) which supports RS485 on > the UARTs of the BBB?
The 4.x-series ti kernels use the omap8250 driver which does not have RS485 support (yet). An initial patchset was just recently submitted for 8250 support of RS485 but needs some more work before it will be accepted into mainline (4.5 at the earliest). If you can build your own kernel, you can switch back to the omap-serial driver which still offers RS485 support. Note if you do switch, you will need to change your user-space console/tty ports back to ttyO*. Regards, Peter Hurley -- 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 [email protected]. For more options, visit https://groups.google.com/d/optout.
