Re: I2C and devicetrees

[Stephen Warren <swarren-3lzwWm7+Weoh9ZMKESR00Q@public.gmane.org>]

On 12/11/2012 01:21 PM, Olof Johansson wrote:
> [+devicetree-discuss]
> 
> On Wed, Dec 5, 2012 at 2:36 PM, Peter Huewe <PeterHuewe-Mmb7MZpHnFY@public.gmane.org> wrote:
>> Hi,
>>
>> I have a short question about the relations between i2c and devicetrees.
>>
>> I was wondering
>> is the device part of the compatible string of a (trivial) i2c device
>> instanciated via devicetree _always_ identical to name in i2c_client.name ?
>> Or can it be somehow different?
> 
> It can be different, but the driver will then need to add a OF table
> that matches the probing. By default the i2c/dt core code will strip
> off the vendor prefix (before ",") and try probing with the rest of
> the device name. If that doesn't match the client name, that is when
> you need the additional table.

While relying on the prefix stripping works, I think I recall Grant
mentioning that people shouldn't rely on it - namely that any I2C device
that gets instantiated from DT should contain the OF match table
explicitly. I CC'd Grant in case I'm mis-quoting him.