host: Rock64 headers definition

[brusan]

After reviewing the Pine64 folder I realize my Go fingers are somewhat too inexperienced to contribute to this fantastic project :) Still, I'd like to help out with any info I can provide if there are plans for supporting the Rock64. As you are certainly aware, there are a number of differences between the Pine64 and the Rock64 when it comes to ports.

br/brusan

[maruel]

Do you have one available? If so, you could extract /proc/devicetree/model and you could start something from there. The first step is to implement Present() bool

[maruel]

Renamed the issue since as long sysfs works, basic functionality should be there.

[brusan]

Yes, I have one running here. Will dig into it - and probably fail miserably :)

[maruel]

Here's a simple example for the CHIP: https://github.com/google/periph/blob/master/host/chip/chip.go#L125

[brusan]

Ok, thank you, I'll give it a try but be warned - I may need some help...

[brusan]

I have implemented Present() bool, had to take a different route as compared to Pine64 but it works ok now. The /proc/devicetree/model tree is not available in this distro but seems to be at /sys/firmware/devicetree/base. uname -a => Linux rock64 4.4.77-rockchip-ayufan-136 #1 SMP Thu Oct 12 09:14:48 UTC 2017 aarch64 GNU/Linux I guess my next step would be looking at the CHIP example above and go from there?

[brusan]

Btw, I discovered some disturbing info regarding the SD-card and the GPIO on the Rock64. Seems like several of the GPIO ports can not be used unless running the system from an eMMC card.

[maruel]

/proc/device-tree/compatible is equivalent to /sys/firmware/devicetree/base/compatible, It'd device-tree, not devicetree, sorry I typo'ed above.

It happens that not all pins can be used, for example on the Raspberry Pi there's a few unusable GPIOs since they are using by the SDCard interface, this is normal.

[maruel]

For the bcm283x driver, I decided against exposing these (GPIO47 to 53) so apps do not play with them by accident.

[brusan]

Ok, those pins should not be exposed. There is a special case in the Rock64 case where they are available provided you boot the device from an eMMC-card but as I can not see how to detect that in the code I leave it out for now. I started of from a copy of the Pine64 code. There are several headers on the Pine64 that are not present on the Rock64 (e.g. Euler bus and expansion bus). Is it enough if I delete those sections from the rock64.go file or should I also make changes in other files?

[maruel]

You need to only put the relevant buses. While it's also created by the same company "pine64" as the "pine64", it's using a completely different CPU. So while you can take inspiration from the package pine64, it's definitely a different beast.

[brusan]

Thank you. Btw I drop the rock64 directory here as it stands right now just in case someone else would like to contribute. rock64.zip

[maruel]

The best way to contribute is to use GitHub Pull Request system:

• Visit https://github.com/google/periph
• Click "Fork" on the top right
• You'll get https://github.com/brusan/periph
• Try to run git clone [email protected]:brusan/periph
  • It will fail if you never used ssh. Try git clone https://github.com/brusan/periph
  • There's more documentation at https://help.github.com/articles/cloning-a-repository/ and https://help.github.com/articles/which-remote-url-should-i-use/.
• Do your change
• Run git add .
• Run git commit and enter a description
• Run git push to push your change to your fork.
• Create a pull request; https://help.github.com/articles/creating-a-pull-request/

Do you want to try this?

[brusan]

Thank you for a great description. I'll continue working "offline" for a while since I have to make sure my project is making progress before the motorcycle track riding season starts up here in Sweden. Hence I am for the moment switching over to a Pi 3B+ platform to gain momentum and will return to the drivers in a few weeks.

[maruel]

As I don't personally have a Rock64, unless I magically receive one in the mail I'll have to wait for someone to contribute the headers.

[maruel]

I'll close this issue since while the original Rock64 is still available at https://pine64.com/product-category/single-board-computers/, it is not competitive and I didn't get additional requests for support in 5 years. If you believe this should be done, please file a new issue at https://github.com/periph/host. Thanks.