[PATCH] arm64: dts: imx8m: Fix the SPI chipselect polarity

[Shawn Guo]

On Wed, Aug 19, 2020 at 07:02:19PM -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>

Applied, thanks.