Re: [RFC PATCH 1/4] spi: spidev: Add Google SPI flash compatible string

Baruch Siach
2015-05-19T19:53:05Z

Hi Javier,

On Tue, May 19, 2015 at 03:34:11PM +0200, Javier Martinez Canillas wrote:
> Google Chromebooks have a SPI flash that is used to store firmware and
> different system parameters and data (i.e: Google Binary Block flags).
>
> Since there isn't a driver for it yet, the spidev interface is used to
> access the flash from user-space (i.e: using the flashrom tool).
>
> Add a "google,spi-flash" compatible string so the Device Tree sources
> use it instead of the "spidev" compatible which does not describe the
> real HW and is just a Linux implementation detail.
>
> A generic "google,spi-flash" OF device ID is used instead of the actual
> vendor/model because these chips are commodity parts that are sourced
> from multiple vendors. So specifying the exact vendor and model in the
> DTS will add a maintenance burden with no real gain (the parts are 100%
> compatible anyways) and will likely result in it simply being wrong for
> a sizeable fraction of the machines.

The compatible string and dt binding should be documented somewhere under
Documentation/devicetree/bindings/. Also, please keep the dt list on Cc for dt
related patches.

baruch

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