On 2016-08-01 11:19, Tomeu Vizoso wrote:
> On 15 April 2016 at 17:35, Jon Hunter <jonathanh@xxxxxxxxxx> wrote:
>> Hi all,
>>
>> For Tegra we have an i2c device for display port, namely the display
>> port auxiliary channel (or dpaux) as specified by the display port
>> standard. If an design using Tegra does not utilise the display port
>> interface, then the pads assigned to the dpaux can be re-assigned to
>> another generic i2c controller (i2c6 for Tegra124/210). In other words,
>> the pads can be re-used for a generic i2c interface.
>>
>> The registers that control whether the pads are mapped to the dpaux or
>> i2c6 are located in the dpaux register space. Therefore, I am looking at
>> adding pin controller support for dpaux so that i2c6 can request these
>> pads if it is enabled and I was hoping to add a pinmux node the to dpaux
>> device in device-tree to do this. For example, something like ...
>>
>> dpaux@0,545c0000 {
>> ...
>>
>> /* pinctrl node */
>> pinmux {
>> ...
>> };
>> };
>>
>> Although the above works, when doing this I noticed that when the device
>> booted, I would seeing the following error messages on boot ...
>>
>> i2c i2c-5: of_i2c: modalias failure on ...
>>
>> These error messages being caused by the new pinmux node because it is
>> not recognised as an i2c device. To avoid this error messages we have
>> come up with a couple solutions but wanted to get some feedback on the
>> best approach.
>
> Hi,
>
> I'm finding this issue as well on Rockchip SoCs, this is the specific
> node that is raising this warning when an adapter is registered with
> it:
>
> edp: dp@ff970000 {
> compatible = "rockchip,rk3288-dp";
> ...
> ports {
> ...
> };
> };
>
> Has there been any agreement since this thread waned?
>
> Thanks,
>
> Tomeu
This is currently soaking in linux-next:
dt-bindings: i2c: Add support for 'i2c-bus' subnode
https://git.kernel.org/cgit/linux/kernel/git/wsa/linux.git/commit/?h=i2c/for-next&id=98b00488459e
i2c: core: Add support for 'i2c-bus' subnode
https://git.kernel.org/cgit/linux/kernel/git/wsa/linux.git/commit/?h=i2c/for-next&id=7e4c224abfe8
Cheers,
Peter
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