Re: [PATCH v2 1/2] dt-bindings: spi: Qualcomm Quad SPI(QSPI) documentation

From: Trent Piepho
Date: Fri Sep 21 2018 - 14:33:43 EST


On Fri, 2018-09-21 at 10:39 -0700, Mark Brown wrote:
> On Fri, Sep 21, 2018 at 10:30:57AM -0700, Stephen Boyd wrote:
> > Quoting Ryan Case (2018-09-20 15:40:54)
> > > +Required properties:
> > > +- compatible: Should contain:
> > > + "qcom,sdm845-qspi"
> > Does someone have a more generic compatible string that can be added
> > here to indicate the type of quad SPI controller this is? I really doubt
> > this is a one-off hardware block for the specific SDM845 SoC.
>
> The idiom for DT is supposed to be to use only device specific names
> unfortunately.

Basically the "first" device the driver can control has it's specific
name used as the generic string. This is used in place of some
internal codename for the core.

Then a newer device will have "foo,XYZ200", "foo,XYZ100" as compatible,
where the 100 was the first device and the 200 is new one. Maybe the
driver cares, or will care, about what device this or maybe it can
drive the device fine without needing to know more than the generic.