[PATCH 1/4] ARM: dts: imx6dl-alti6p: Fix the SPI chipselect polarity

[Shawn Guo]

On Sat, Aug 14, 2021 at 10:27:13AM -0300, Fabio Estevam wrote:
> Hi Shawn,
> 
> On Sat, Jul 17, 2021 at 1:57 AM Oleksij Rempel <o.rempel at pengutronix.de> wrote:
> >
> > On Fri, Jul 16, 2021 at 10:36:56AM -0300, Fabio Estevam wrote:
> > > The conversion of the spi-imx driver to use GPIO descriptors
> > > in commit 8cdcd8aeee28 ("spi: imx/fsl-lpspi: Convert to GPIO descriptors")
> > > helped to detect the following SPI chipselect polarity mismatch on an
> > > imx6q-sabresd for example:
> > >
> > > [    4.854337] m25p80 at 0 enforce active low on chipselect handle
> > >
> > > Prior to the above commit, the chipselect polarity passed via cs-gpios
> > > property was ignored and considered active-low.
> > >
> > > The reason for such mismatch is clearly explained in the comments inside
> > > drivers/gpio/gpiolib-of.c:
> > >
> > > * SPI children have active low chip selects
> > > * by default. This can be specified negatively
> > > * by just omitting "spi-cs-high" in the
> > > * device node, or actively by tagging on
> > > * GPIO_ACTIVE_LOW as flag in the device
> > > * tree. If the line is simultaneously
> > > * tagged as active low in the device tree
> > > * and has the "spi-cs-high" set, we get a
> > > * conflict and the "spi-cs-high" flag will
> > > * take precedence.
> > >
> > > To properly represent the SPI chipselect polarity, change it to active-low
> > > when the "spi-cs-high" property is absent.
> > >
> > > Signed-off-by: Fabio Estevam <festevam at gmail.com>
> >
> > Reviewed-by: Oleksij Rempel <o.rempel at pengutronix.de>
> > Thank you!
> 
> A gentle ping on this series.

Should we have Fixes tags for the patches?

Shawn