On Sunday 14 September 2014 22:11:08 John Syn wrote: > On 9/14/14, 1:55 AM, "David Goodenough" > > <[email protected]> wrote: > >On Saturday 13 September 2014 13:51:17 John Syn wrote: > >> From: <[email protected]> > >> Reply-To: "[email protected]" <[email protected]> > >> Date: Friday, September 12, 2014 at 3:50 AM > >> To: "[email protected]" <[email protected]> > >> Subject: [beagleboard] How to change GPIO Mode > >> > >> > Hey Forum > >> > I hope you can help me. I'm on a education project and I have some > >> > questions. > >> > > >> > I have a problem with the config of the GPIO (I2C-HW-Controller) > >> > > >> > I have two diffrent usecases in my project. > >> > 1. I2C HW-Controller #1 is a master > >> > 2. I2C HW-Controller #1 is a slave > >> > So I have to change the I2C-controller config between the master and > >> > >>the > >> > >> > slave mode. > >> > If it is possible, I should do that while the BBB and his phyton/c++ > >> > program is running. > >> > > >> > Now here are my questions: > >> > * How can I switch between I2C master and slave mode? (Device tree?) > >> > * > >> > * Can I do that while the BBB is running? (Or is a reboot of BBB > >> > necessary?) If its possible give my a nice explanation and not only a > >> > code piece. ;-) I have to learn & understand how all that stuff works. > >> > >> Linux does not support slave mode for either I2C or SPI. Even though > >> > >>the BBB > >> > >> hardware can support SCL being generated on another device, the Linux > >> > >>I2C > >> > >> driver does not support this. Either you have to create your own I2C > >> > >>slave > >> > >> driver or you can do this with the PRU. > > > >Currently that is true, but I noticed some code being proposed on one of > >the > >kernel lists to enable this. So shortly (i.e a kernel release or two) it > >will > >be possible - assuming the code gets accepted. > > You are correct, but I only see work being done on the I2C slave framework: > > https://lkml.org/lkml/2014/9/12/125 > > I don¹t see any work being done on a SPI slave framework. True > > >On the subject of the PRU and its use of I2C, is there any sample code > >around > >that shows this being done? > > The only reference I¹ve seen is a bit banger driver using the PRU: > > https://github.com/mcdonamp/RH_ROBO_Quadcopter/tree/master/code/i2c_bitbang > /pru_sw There is reference to two I2C ports in the global table, but I am unclear as to how to use them. An example from TI would be nice.
David > > Regards, > John > > >David > > > >> Regards, > >> John > >> > >> > Thanks a lot -- 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.
