Hello Mike, On Thu, Feb 7, 2019 at 9:45 AM Mike <puffy.taco@xxxxxxxxx> wrote: > > Hi, > > First, I think this is the right place for questions relating to > rpmsg, but please redirect me if I'm wrong. > > I'm looking to get access to send messages from userspace to the rpmsg > bus, but am not sure the best way. The base of my work is a 4.9 > series kernel for NXP's i.MX7D, Have you seen the imx_rpmsg_tty driver as part of NXP's 4.9 kernel? This is the driver which will create the A7-M4 channel to the other side, and the ttyRPMSG device, with one default endpoint. > but I've been comparing it to mainline > to see if there's anything I could utilize. In particular, I was > looking at the config option RPMSG_CHAR which states: > > "Say Y here to export rpmsg endpoints as device files, usually found > in /dev. They make it possible for user-space programs to send and > receive rpmsg packets." > > I compiled a kernel with that option but I don't see any device files > in /dev. Looking through the code, it seems like only the qcom_smd > driver actually uses this driver, so I assume the Kconfig help text is > somewhat misleading? > > Is there a general purpose way to open a channel from userspace? Or > am I best off using the name service from the remote processor to > announce all the channels I want and write a generic driver that > creates a char device to expose an interface to each? I too would be interested to know how far ahead is the mainstream on that. It would be great if there is a new or updated driver which creates ttyrpmsg devices dynamically for the new endpoints that application may create. I was going to expand the imx_rpmsg_tty to do this just for ones I need, but of course would rather use an already working driver for this of exists. > Thanks, > Mike Regards, Denis
