On Tue, Sep 6, 2022 at 8:33 AM Linus Walleij <linus.walleij@xxxxxxxxxx> wrote: > > On Tue, Sep 6, 2022 at 3:20 PM Andy Shevchenko > <andriy.shevchenko@xxxxxxxxx> wrote: > > On Tue, Sep 06, 2022 at 03:08:00PM +0200, Linus Walleij wrote: > > > On Tue, Sep 6, 2022 at 2:19 PM Andy Shevchenko > > > <andriy.shevchenko@xxxxxxxxx> wrote: > > > > On Tue, Sep 06, 2022 at 09:28:16AM +0100, Martyn Welch wrote: > > > > > From: Martyn Welch <martyn.welch@xxxxxxxxxxxxx> > > > > > > > > > > The NXP PCAL6534 is a 34-bit I2C I/O expander similar to the PCAL6524. The > > > > > Diodes PI4IOE5V6534Q is a functionally identical chip provided by Diodes > > > > > Inc. > > > > > > > > ... > > > > > > > > > + oneOf: > > > > > + - items: > > > > > + - const: diodes,pi4ioe5v6534q > > > > > + - const: nxp,pcal6534 > > > > > > > > ^^^ > > > > > > > > > + - items: > > > > > + - enum: > > > > > > > > > + - nxp,pcal6534 > > > > > > > > ^^^ > > > > > > > > Not sure why is this dup? > > > > > > No that is how DT compatibles work. One version of the component, > > > bought from NXP will look like this: > > > > > > compatible = "nxp,pcal6534"; > > > > > > Another version bought from diodes will look like this: > > > > > > compatible = "diodes,pi4ioe5v6534q", "nxp,pcal6534"; > > > > > > Then the drivers are probed matching from left to right, > > > with the "most compatible" matching first. > > > > > > This also answers your question on the implementation. > > > > Then I don't understand why the const list above is only for new chips > > and not for the old one where the same can be applied. > > That's YAML. It's because the const list is the most compact way > to express two precise items following after each other, and the enum > list is an implicit list of single-item const:s, as you cannot enum > tuples. > > > Mysterious ways of DT... > > It's not DT, it's YAML that is mysterious. DT itself is a pretty > straight-forward > grammar, while YAML is a meta-grammar describing the DT grammar Not YAML, but json-schema is the grammar. YAML is just the file format and it's a JSON compatible subset of YAML (no anchors, refs, tags). > (ML stands for Meta Language). Huh? yaml.org says: YAML Ain't Markup Language™ Rob
