diff mbox series

[RFC,4/5] dt-bindings: spi/spi-pxa2xx: Add ready GPIO signal

Message ID 20180917120808.20224-5-lkundrak@v3.sk (mailing list archive)
State New, archived
Headers show
Series Signal pxa2xx SPI slave readiness via handshake signal [Was: SPI Slave with handshaking] | expand

Commit Message

Lubomir Rintel Sept. 17, 2018, 12:08 p.m. UTC
This this is used to let the SPI master know that our FIFO is filled and
we're ready to service a transfer. Only useful in slave mode.

A signal like this is used by an embedded controller on a OLPC XO 1.75
machine, that happens to be a SPI master.

Signed-off-by: Lubomir Rintel <lkundrak@v3.sk>
---
 Documentation/devicetree/bindings/spi/spi-pxa2xx.txt | 2 ++
 1 file changed, 2 insertions(+)

Comments

Geert Uytterhoeven Sept. 17, 2018, 12:25 p.m. UTC | #1
Hi Lubomir,

On Mon, Sep 17, 2018 at 2:08 PM Lubomir Rintel <lkundrak@v3.sk> wrote:
> This this is used to let the SPI master know that our FIFO is filled and
> we're ready to service a transfer. Only useful in slave mode.
>
> A signal like this is used by an embedded controller on a OLPC XO 1.75
> machine, that happens to be a SPI master.
>
> Signed-off-by: Lubomir Rintel <lkundrak@v3.sk>

Thanks for your patch!

> --- a/Documentation/devicetree/bindings/spi/spi-pxa2xx.txt
> +++ b/Documentation/devicetree/bindings/spi/spi-pxa2xx.txt
> @@ -12,6 +12,8 @@ Optional properties:
>  - cs-gpios: list of GPIO chip selects. See the SPI bus bindings,
>    Documentation/devicetree/bindings/spi/spi-bus.txt
>  - spi-slave: Empty property indicating the SPI controller is used in slave mode.
> +- ready-gpio: GPIO used to signal a SPI master that the FIFO is filled
> +  and we're ready to service a transfer. Only useful in slave mode.

Even for the case of a single GPIO, the preferred naming is "ready-gpios".

Gr{oetje,eeting}s,

                        Geert
diff mbox series

Patch

diff --git a/Documentation/devicetree/bindings/spi/spi-pxa2xx.txt b/Documentation/devicetree/bindings/spi/spi-pxa2xx.txt
index 89b2832283e3..681a82b40e6f 100644
--- a/Documentation/devicetree/bindings/spi/spi-pxa2xx.txt
+++ b/Documentation/devicetree/bindings/spi/spi-pxa2xx.txt
@@ -12,6 +12,8 @@  Optional properties:
 - cs-gpios: list of GPIO chip selects. See the SPI bus bindings,
   Documentation/devicetree/bindings/spi/spi-bus.txt
 - spi-slave: Empty property indicating the SPI controller is used in slave mode.
+- ready-gpio: GPIO used to signal a SPI master that the FIFO is filled
+  and we're ready to service a transfer. Only useful in slave mode.
 
 Child nodes represent devices on the SPI bus
   See ../spi/spi-bus.txt