Re: [PATCH v5 5/9] dt-bindings: spi: Adjust the bindings for the FSL QSPI driver

[Rob Herring <robh@kernel.org>]

On Tue, 13 Nov 2018 13:47:37 +0000, Schrempf Frieder wrote:
> Adjust the documentation of the new SPI memory interface based
> driver to reflect the new drivers settings.
> 
> The "old" driver was using the "fsl,qspi-has-second-chip" property to
> select one of two dual chip setups (two chips on one bus or two chips
> on separate buses). And it used the order in which the subnodes are
> defined in the dt to select the CS, the chip is connected to.
> 
> Both methods are wrong and in fact the "reg" property should be used to
> determine which bus and CS a chip is connected to. This also enables us
> to use different setups than just single chip, or symmetric dual chip.
> 
> So the porting of the driver from the MTD to the SPI framework actually
> enforces the use of the "reg" properties and makes
> "fsl,qspi-has-second-chip" superfluous.
> 
> As all boards that have "fsl,qspi-has-second-chip" set, also have
> correct "reg" properties, the removal of this property shouldn't lead to
> any incompatibilities.
> 
> The only compatibility issues I can see are with imx6sx-sdb.dts and
> imx6sx-sdb-reva.dts, which have their reg properties set incorrectly
> (see explanation here: [2]), all other boards should stay compatible.
> 
> Also the "big-endian" flag was removed, as this setting is now selected
> by the driver, depending on which SoC is in use.
> 
> [2] https://patchwork.ozlabs.org/patch/922817/#1925445
> 
> Signed-off-by: Frieder Schrempf <frieder.schrempf@kontron.de>
> ---
>  .../devicetree/bindings/spi/spi-fsl-qspi.txt      | 18 ++++++++----------
>  1 file changed, 8 insertions(+), 10 deletions(-)
> 

Reviewed-by: Rob Herring <robh@kernel.org>