Re: I2C slave support on Xilinx Zybo

Re: I2C slave support on Xilinx Zybo

[Wolfram Sang]

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Hi,

> I am currently working on getting slave support for the Xilinx Zybo platform
> with kernel version 3.19.0.

Cool! Any code you can show for the xilinx driver?

> These are the steps I have taken so far in userspace:
> 
> # echo eeprom 0x28 > /sys/bus/i2c/devices/i2c-1/new_device
> # i2c i2c-1: new_device: Instantiated device eeprom at 0x29

Ehrm, no, you need to use the slave eeprom driver here. Gosh, did I
paste the wrong shell command into the docs? How emberrasing...

> I am new to asking question within the kernel emailing list, so I hope I do not
> offend anybody and I am certainly not trying. 

No worries, you came to the right place.

   Wolfram


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Re: I2C slave support on Xilinx Zybo

[Wolfram Sang]

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> I don't think necessarily there is an error in the docs, it was probably my

Nope, the docs are wrong. Try this:

echo slave-24c02 0x28 > /sys/bus/i2c/devices/i2c-1/new_device

That should be it. I am travelling at the moment, so I can't double
check, sadly. But after that, you should have a new device at 1-0028
bound to the i2c-slave-eeprom driver.

Thanks for the code! Haven't looked in detail yet, needs some polishing
to match kernel coding style. But as they say, first make it work, then
make it beautiful.

Good luck!

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Re: I2C slave support on Xilinx Zybo

[Tim Bakker]

I think that worked, I can see the device  popup in the
/sys/bus/i2c/drivers/i2c-slave-eeprom folder, and looking at the
uevent file in the created device (1-0028) gives me:

DRIVER=i2c-slave-eeprom
MODALIAS=i2c:slave-24c02


Sorry to hackle you more but I am still getting the continuous message
(when the console log level has changed to 8):

i2c-slave-eerpom 1-0028: uevent

Should I just ignore this for now and see if I can get the slave
support to work or do you think this might be in an issue in my
implementation of the slave support in the xilinx driver.

Thanks,
Tim




On Sat, Jun 13, 2015 at 5:49 AM, Wolfram Sang <wsa-z923LK4zBo2bacvFa/9K2g@public.gmane.org> wrote:
>
>> I don't think necessarily there is an error in the docs, it was probably my
>
> Nope, the docs are wrong. Try this:
>
> echo slave-24c02 0x28 > /sys/bus/i2c/devices/i2c-1/new_device
>
> That should be it. I am travelling at the moment, so I can't double
> check, sadly. But after that, you should have a new device at 1-0028
> bound to the i2c-slave-eeprom driver.
>
> Thanks for the code! Haven't looked in detail yet, needs some polishing
> to match kernel coding style. But as they say, first make it work, then
> make it beautiful.
>
> Good luck!



-- 
Tim Bakker, PhD
Research Assistant
Virginia Commonwealth University
601 W. Main St.
Richmond, VA 23284-3068
Rm. 216

Re: I2C slave support on Xilinx Zybo

[Wolfram Sang]

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> Sorry to hackle you more but I am still getting the continuous message
> (when the console log level has changed to 8):
> 
> i2c-slave-eerpom 1-0028: uevent

I will check that next week when I am back. I didn't use udev or
something similar when developing this framework, so I didn't notice.

> Should I just ignore this for now and see if I can get the slave
> support to work or do you think this might be in an issue in my
> implementation of the slave support in the xilinx driver.

Since I don't know and can't test anything at the moment, I'd say just
keep going :)


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