Fedora 25 on Raspberry PI 2 - SPI, I2C - device tree overlays?

[Jan]

Hi,
I'm trying to understand if it is possible, and if yes then how, to enable
I2C and SPI.
On Raspbian one had to edit config.txt, but here overlays directory on
partition is empty.
Is there somewhere documented how to populate folder?
FAQ on https://fedoraproject.org/wiki/Raspberry_Pi is a bit unclear for me,
when it says no support for HATs.
It describes that some manual steps are required. That's fine, however I'm
not kernel developer,
I just play with some simple sensors. Using simple python scripts.
Is a quick answer to such usage: "Not yet"?

Right now Fedora 25 installed nicely on PI, and works great as Fedora box,
imap server, some www page.

Regards
  Jan

[Peter Robinson]

On Thu, Nov 24, 2016 at 3:35 PM, Jan  wrote:
> Hi,
> I'm trying to understand if it is possible, and if yes then how, to enable
> I2C and SPI.
> On Raspbian one had to edit config.txt, but here overlays directory on
> partition is empty.
> Is there somewhere documented how to populate folder?
> FAQ on https://fedoraproject.org/wiki/Raspberry_Pi is a bit unclear for me,
> when it says no support for HATs.
> It describes that some manual steps are required. That's fine, however I'm
> not kernel developer,
> I just play with some simple sensors. Using simple python scripts.
> Is a quick answer to such usage: "Not yet"?

So i2c is enabled out of the box so you should be able to scan for i2c
devices with i2cdetect and use them. The spi kernel module is shipped
but I'm not sure it's enabled in the device tree upstream yet (I've
not looked closely).

We don't support overlays via the config.txt file. As I get time to
test and document all the details will be updated in the wiki page.

Peter

[Jan]

> On Thu, Nov 24, 2016 at 3:35 PM, Jan <spljaa(a)gmail.com&gt; wrote:
>
> So i2c is enabled out of the box so you should be able to scan for i2c
> devices with i2cdetect and use them. The spi kernel module is shipped
> but I'm not sure it's enabled in the device tree upstream yet (I've
> not looked closely).
>
> We don't support overlays via the config.txt file. As I get time to
> test and document all the details will be updated in the wiki page.
>
> Peter

Ok,
Indeed i2c should work, at least i2cdetect shows expected output.

I had some simple python code reading sensors working on raspbian.
And it looks like is not as simple to run it on Fedora. I'm hitting some core dump when calling GPIO

systemd-coredump[1499]: Process 1497 (test.py) of user 0 dumped core.
                                           Stack trace of thread 1497:
                                           #0  0x00000000b69a8e28 gpio_function (_GPIO.so)

Which is probably side question. And result of my lack of knowledge.

What I would like to highlight that all what I expect from Fedora is working great. It is the part of PI interfaces that I find hard to run.

Regards
  Jan

Hi,

Any luck getting fbTFT type of overlay working from uboot onwards?  I have a waveshare32b touch screen model which I'm hoping someone has working.

Will there be a fbtft_device kernel module supported in ARM fedora soon?

Thanks,
Eric

[Peter Robinson]

On Sat, Dec 31, 2016 at 2:39 PM,   wrote:
> Hi,
>
> Any luck getting fbTFT type of overlay working from uboot onwards?  I have a waveshare32b touch screen model which I'm hoping someone has working.
>
> Will there be a fbtft_device kernel module supported in ARM fedora soon?

Please don't higjack unrelated topics (gpio vs displays).

We don't plan on enabling fbTFT at this time. The drivers are in the
staging section of the kernel and there is discussion of dropping them
entirely due to the frame buffer stuff being deprecated. We will
enable what ever kms/drm solution is agreed on upstream once that
agreement happens.