[PATCH] dt-bindings: mtd: jedec,spi-nor: Document support for more MT25QU parts
robh at kernel.org
Mon Dec 5 08:33:06 PST 2022
On Fri, Dec 02, 2022 at 02:56:01PM +0100, Geert Uytterhoeven wrote:
> Hi Michael,
> On Fri, Dec 2, 2022 at 2:50 PM Michael Walle <michael at walle.cc> wrote:
> > Am 2022-12-02 14:37, schrieb Geert Uytterhoeven:
> > > Document support for the Micron MT25QU256A and MT25QU512A Serial NOR
> > > FLASHes.
> > >
> > > Merge the new entries with the existing entry for MT25QU02G.
> > >
> > > Signed-off-by: Geert Uytterhoeven <geert+renesas at glider.be>
> > > ---
> > > mt25qu512a is already in active use, causing "make dtbs_check" errors.
> > > mt25qu256a is supported by the Linux spi-nor driver, but there are no
> > > upstream users yet.
> > Is it encouraged to use the specific compatible with SPI-NOR flashes?
> > As far as I know it isn't. The spi-nor subsys tries hard to identify
> > any flashes at runtime and any additional information in the device tree
> > is used as a last resort (just for flashes which doesn't support the
> > read jedec id command yet). And usually boards have different sources
> > for flash chips, so hardcoding a particular part in the device tree
> > doesn't make sense.
> Thanks, I am aware there have been pushbacks when trying to
> document more compatible values.
> IMHO either all or none of them should be documented.
> If device-specific compatible values are discouraged, the bindings
> should be updated to reflect that, and document a single compatible
> value ("jedec,spi-nor") only.
That's already allowed, so there's your answer.
The caveat is don't be adding them later to your DT when you find an
issue and new quirk properties will probably be rejected.
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