[U-Boot] [PATCH 1/2] SPI: Add support for preamble bytes

[Simon Glass]

On Fri, Mar 22, 2013 at 12:29 AM, Rajeshwari Shinde
<rajeshwari.s at samsung.com> wrote:
> A SPI slave may take time to react to a request. For SPI flash devices
> this time is defined as one bit time, or a whole byte for 'fast read'
> mode.
>
> If the SPI slave is another CPU, then the time it takes to react may
> vary. It is convenient to allow the slave device to tag the start of
> the actual reply so that the host can determine when this 'preamble'
> finishes and the actual message starts.
>
> Add a preamble flag to the available SPI flags. If supported by the
> driver then it will ignore any received bytes before the preamble
> on each transaction. This ensures that reliable communication with
> the slave is possible.
>
> Signed-off-by: Simon Glass <sjg at chromium.org>
> Signed-off-by: Rajeshwari Shinde <rajeshwari.s at samsung.com>

Acked-by: Simon Glass <sjg at chromium.org>