On Tue, 11 Dec 2012 13:56:08 -0700, Stephen Warren <swarren@xxxxxxxxxxxxx> wrote: > On 12/11/2012 01:21 PM, Olof Johansson wrote: > > [+devicetree-discuss] > > > > On Wed, Dec 5, 2012 at 2:36 PM, Peter Huewe <PeterHuewe@xxxxxx> 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. I'm not quite that strict about it. The behaviour described above is based merely on a heuristic but for a lot of drivers that don't do anything special it works just fine. The moment you need to identify a specific device it becomes better to use an of match table. g. -- Grant Likely, B.Sc, P.Eng. Secret Lab Technologies, Ltd. -- To unsubscribe from this list: send the line "unsubscribe linux-i2c" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
