Re: [PATCHv2 1/2] Documentation: dt: spi: Add GPIO Slave Select Parameter
From: Geert Uytterhoeven
Date: Fri Oct 07 2016 - 15:34:32 EST
On Fri, Oct 7, 2016 at 4:56 PM, <tthayer@xxxxxxxxxxxxxxxxxxxxx> wrote:
> From: Thor Thayer <tthayer@xxxxxxxxxxxxxxxxxxxxx>
> Some SPI masters require the slave to be selected before a
> transaction can occur - even in the case of GPIO chip select.
> This patch adds a GPIO slave select parameter to indicate
> the slave needs to be selected in the GPIO CS case.
> Signed-off-by: Thor Thayer <tthayer@xxxxxxxxxxxxxxxxxxxxx>
> v2 Add to SPI framework - add bindings.
> Documentation/devicetree/bindings/spi/spi-bus.txt | 1 +
> 1 file changed, 1 insertion(+)
> diff --git a/Documentation/devicetree/bindings/spi/spi-bus.txt b/Documentation/devicetree/bindings/spi/spi-bus.txt
> index 4b1d6e7..3a006bc 100644
> --- a/Documentation/devicetree/bindings/spi/spi-bus.txt
> +++ b/Documentation/devicetree/bindings/spi/spi-bus.txt
> @@ -24,6 +24,7 @@ support describing the chip select layout.
> Optional properties:
> - cs-gpios - gpios chip select.
> - num-cs - total number of chipselects.
> +- gpio-ss - use internal slave select with gpio chip select.
> If cs-gpios is used the number of chip selects will be increased automatically
> with max(cs-gpios > hw cs).
To me, this looks more like a new flag the SPI controller driver should
set in spi_master.flags, instead of a DT property.
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds