Re: [PATCH 4/4] spi: Document option to insert delay between transactions

From: Geert Uytterhoeven
Date: Thu Jun 30 2016 - 03:25:55 EST


CC devicetree

On Thu, Jun 30, 2016 at 5:54 AM, <apronin@xxxxxxxxxxxx> wrote:
> From: Andrey Pronin <apronin@xxxxxxxxxxxx>
>
> Some devices may need CS to be deasserted for some time
> between transactions. Added a new capability to guarantee
> a delay between SPI transactions for the device.
>
> Signed-off-by: Andrey Pronin <apronin@xxxxxxxxxxxx>
> ---
> Documentation/devicetree/bindings/spi/spi-bus.txt | 2 ++
> 1 file changed, 2 insertions(+)
>
> diff --git a/Documentation/devicetree/bindings/spi/spi-bus.txt b/Documentation/devicetree/bindings/spi/spi-bus.txt
> index 1b7ffd4..87c117a 100644
> --- a/Documentation/devicetree/bindings/spi/spi-bus.txt
> +++ b/Documentation/devicetree/bindings/spi/spi-bus.txt
> @@ -70,6 +70,8 @@ contain the following properties.
> sleep if there was no SPI activity (msec).
> - cs-wake-duration - (optional) Time it takes the device to wake up after
> toggling CS if it went to sleep (msec).
> +- xfer-delay - (optional) Delay to insert between SPI transactions
> + to guarantee that CS is deasserted at least for some time.
>
> Some SPI controllers and devices support Dual and Quad SPI transfer mode.
> It allows data in the SPI system to be transferred in 2 wires(DUAL) or 4 wires(QUAD).
> --
> 2.6.6