On Sun, Jun 11, 2017 at 3:04 PM, mzimmers <[email protected]> wrote:
> Hi William - > > Yeah, sorry about that...I was being lazy. The output of perror says > "Connection timed out" though the first time the write is called, errno is > 22. In the next write attempts, errno is 110 (agreeing with perror). I'm > trying to write an 8 to register 45 (POWER_CTL). > > But, before we worry too much about this error, let me ask this: if bit > banging isn't a good idea, can you point me to a reference that describes > the workings of the file I/O to the I2C? I'm new to embedded Linux (used to > an RTOS) so bit-banging is more natural to me. I need to learn a little > about what's "under the hood" of the Linux technique for this kind of I/O. > I think looking at the source code for the various tools included in the i2c-tool debian package would be a good place to start. Also seeing if there is a driver for your hardware in the Linux kernel might be a good place to just gloss over ( at least ) to see how they're doing things. I've done some lower level Linux dev I2C as well, and have probably run into similar issues you're facing here. I'm not an expert. But what I did realize in my own case that communicating with the hardware I am using( a real time clock ) that using a different approach was much better. In my case. I have some I2C code I've written in C, but at this very moment I'm busy with my own things, and not quite sure where that code is. At some point however, I could look into my code and refresh my memory, and give you an idea of what I did for a different situation. So bit banging I2C would be a terrible idea in my opinion, because you would using a lot of processor time. After that, there is very little chance you'd be better at doing this than is what already is done in drivers already. It could be worth a look, but I think you'd be spinning your wheels. However, if performance, and a lower processor load was a definite must. You could probably use an external MCU that used hardware assisted I2C, and design something like an I2C to UART bridge . . .which could be useful, I guess. -- 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]. To view this discussion on the web visit https://groups.google.com/d/msgid/beagleboard/CALHSORr3nq7S%3DgP%3DKXiVorR4J%2B3v2p1CnV4CvmsmOOAYka3wfw%40mail.gmail.com. For more options, visit https://groups.google.com/d/optout.
