i2c driver develpment with diolan DLN-2 / ACPI?

[Daniel Baluta]

On Sat, Apr 30, 2016 at 6:10 PM, Martin Kepplinger <martink at posteo.de> wrote:
> Am 2016-04-27 um 13:51 schrieb Daniel Baluta:
>> On Wed, Apr 27, 2016 at 2:36 PM, Martin Kepplinger <martink at posteo.de> wrote:
>>> Hi roberta or anyone who uses a diolan i2c/spi bridge device,
>>>
>>> I try to do get the kernel driver for the connected chip loaded, but I'm
>>> having some trouble getting it right.
>>>
>>> Cables are connected to the device (i2c), and the (mainline) kernel
>>> driver for the diolan DLN-2 device is compiled and loaded on plugin.
>>>
>>> I don't use any of their (userspace) software.
>>>
>>> Now I get a new i2c bus and can manually instanciate my driver
>>>
>>> root at laptop:/sys/bus/i2c/devices/i2c-7# echo mma8452 0x1c > new_device
>>>
>>> and the driver loads. (Now for development, later maybe for merging) I
>>> added acpi support, I guess I'd need it, but ACPI_HANDLE(&client->dev)
>>> isn't true (during probe) hence we don't continue. I append my
>>> adding-acpi-patch below.
>>>
>>> How do you do it?
>>>
>>> Do *you* manually instantiate your i2c-driver during development with
>>> your diolan device or should it somehow even get loaded automatically?
>>>
>>
>> Hi Martin,
>>
>> Please also use the following two patches:
>>
>> https://lkml.org/lkml/2014/12/16/290
>> https://lkml.org/lkml/2014/12/16/289
>>
>> How does your setup looks like?
>>
>
> Those patches don't apply anymore, also because of API changes. I save
> them but I'll ignore the ACPI problem for now. Oh well, for development
> only, I skip it and go ahead and try to write and read registers.
>
> Different problem:
>
> i2c_smbus_read_byte_data always returns with "Protocol Error".
>
> DLN-2 jumpers are correct. Is there anything special to consider, using
> the DLN-2, regardless of which chip you are talking to?
>

Please check the wiring. Also make sure you run at the correct
voltage for your specific chip.

One other thing, is the firmware version.

http://dlnware.com/Downloads

AFAIK Diolan by default comes in U2C compatiblity mode
which will not work with DLN2 drivers.

Daniel.