GSoC Linux UIO driver for PRU
Hi, After I made sure that my fdt is correct I wondered why the pruss was still not accessible. When I researched more about userspace drivers in Linux I found out, that I have overseen the pru UIO module in Linux. This is the part that links the PRUs to the /dev/uio[0-7]. Which then would be used by the sources I currently use. The UIO source is available here: https://github.com/beagleboard/linux/blob/3.8/drivers/uio/uio_pruss.c However this requires the linux UIO lib to load the modules and abstract the device into a file. While researching I also found that BSD has a PRU driver. Also this driver is more feature rich as it support PRU debugging. The sources can be found her: https://bitbucket.org/rpaulo/libpru/src/default/ Additionally I found these sources in the FreeBSD tree: https://github.com/freebsd/freebsd/blob/250e158ddf52459661439141407bca505d199c19/sys/arm/ti/ti_pruss.c This code also registers the PRUs in /dev/. On the other hand the BSD drivers have no documentation at all. These are the code lines that will fail without a file in /dev. Linux: https://github.com/nilhoel1/rtems-pru/blob/master/ti/prussdrv.c#L265 BSD: https://bitbucket.org/rpaulo/libpru/src/5cb7271533a96d177e73492f7cc40fa4b28396a5/ti-pru.c#lines-614 So my questions are: 1. How are drivers registered to /dev in RTEMS? (examples) 2. Which driver would be a better starting point to bring pruss support to RTEMS? Best, Nils Hölscher ___ devel mailing list devel@rtems.org http://lists.rtems.org/mailman/listinfo/devel
Re: GSoC Linux UIO driver for PRU
On 13/7/19 5:16 pm, Nils Hölscher wrote: > Hi, > > After I made sure that my fdt is correct I wondered why the pruss was still > not > accessible. > When I researched more about userspace drivers in Linux I found out, that I > have > overseen the pru UIO module in Linux. > This is the part that links the PRUs to the /dev/uio[0-7]. > Which then would be used by the sources I currently use. > The UIO source is available here: > https://github.com/beagleboard/linux/blob/3.8/drivers/uio/uio_pruss.c > However this requires the linux UIO lib to load the modules and abstract the > device into a file. > > While researching I also found that BSD has a PRU driver. > Also this driver is more feature rich as it support PRU debugging. > The sources can be found her: > https://bitbucket.org/rpaulo/libpru/src/default/ > Additionally I found these sources in the FreeBSD tree: > https://github.com/freebsd/freebsd/blob/250e158ddf52459661439141407bca505d199c19/sys/arm/ti/ti_pruss.c > This code also registers the PRUs in /dev/. > On the other hand the BSD drivers have no documentation at all. > > These are the code lines that will fail without a file in /dev. > Linux: https://github.com/nilhoel1/rtems-pru/blob/master/ti/prussdrv.c#L265 > BSD: > https://bitbucket.org/rpaulo/libpru/src/5cb7271533a96d177e73492f7cc40fa4b28396a5/ti-pru.c#lines-614 > > So my questions are: > 1. How are drivers registered to /dev in RTEMS? (examples) I suggest you look at cpukit/include/rtems/io.h and then for examples of this interface being used in the bsp directory. > 2. Which driver would be a better starting point to bring pruss support to > RTEMS? The bitbucket set of drivers look pretty good so I think just use them and add to the beagle bsp. Chris ___ devel mailing list devel@rtems.org http://lists.rtems.org/mailman/listinfo/devel
Re: GSoC Linux UIO driver for PRU
On Sat, Jul 13, 2019 at 1:42 PM Chris Johns wrote: > > > On 13/7/19 5:16 pm, Nils Hölscher wrote: > > Hi, > > > > After I made sure that my fdt is correct I wondered why the pruss was > still not > > accessible. > > When I researched more about userspace drivers in Linux I found out, > that I have > > overseen the pru UIO module in Linux. > > This is the part that links the PRUs to the /dev/uio[0-7]. > > Which then would be used by the sources I currently use. > > The UIO source is available here: > > https://github.com/beagleboard/linux/blob/3.8/drivers/uio/uio_pruss.c > > However this requires the linux UIO lib to load the modules and abstract > the > > device into a file. > > > > While researching I also found that BSD has a PRU driver. > > Also this driver is more feature rich as it support PRU debugging. > > The sources can be found her: > > https://bitbucket.org/rpaulo/libpru/src/default/ > > Additionally I found these sources in the FreeBSD tree: > > > https://github.com/freebsd/freebsd/blob/250e158ddf52459661439141407bca505d199c19/sys/arm/ti/ti_pruss.c > > This code also registers the PRUs in /dev/. > > On the other hand the BSD drivers have no documentation at all. > > > > These are the code lines that will fail without a file in /dev. > > Linux: > https://github.com/nilhoel1/rtems-pru/blob/master/ti/prussdrv.c#L265 > > BSD: > https://bitbucket.org/rpaulo/libpru/src/5cb7271533a96d177e73492f7cc40fa4b28396a5/ti-pru.c#lines-614 > > > > So my questions are: > > 1. How are drivers registered to /dev in RTEMS? (examples) > > I suggest you look at cpukit/include/rtems/io.h and then for examples of > this > interface being used in the bsp directory. > There is a helper in the IO Manager which is implemented as a call to mknod() which is a standard call. > > > 2. Which driver would be a better starting point to bring pruss support > to RTEMS? > > > The bitbucket set of drivers look pretty good so I think just use them and > add > to the beagle bsp. > +1 If needed, > > Chris > ___ > devel mailing list > devel@rtems.org > http://lists.rtems.org/mailman/listinfo/devel ___ devel mailing list devel@rtems.org http://lists.rtems.org/mailman/listinfo/devel
