mfd: cros_ec: spi: Add delay for asserting CS
mfd: cros_ec: spi: Add delay for asserting CS

Some ECs need a little time for waking up before they can accept
SPI data at a high speed. This is configurable via a DT property
"google,cros-ec-spi-pre-delay".

This patch makes the cros_ec_spi driver to cause a delay before
the beginning of a SPI transaction, to make sure that the EC has
already woken up, if the property has been defined in the DTS.

Signed-off-by: Alexandru M Stan <1784cbba6d7675b1eba55eaefe41c7672ad9da3b@chromium.org>
Reviewed-by: Doug Anderson <49983c4a76b998672954ed5edf4a62db4a336502@chromium.org>
Signed-off-by: Chris Zhong <83f0f67e3a475ac31423a7deb3ea3845def2c091@rock-chips.com>
Signed-off-by: Javier Martinez Canillas <039000e09e601bba70626bd0fbe59654c9cf8cac@collabora.co.uk>
Tested-by: Heiko Stuebner <9ab5f52a1ca0bcf4f70d6d9008e02f6134b5b8f2@sntech.de>
Acked-by: Lee Jones <630e34333487a351a857f6b705e04d30b37c1629@linaro.org>
Acked-by: Olof Johansson <8c69ee23f3f44f8162a64d579c1fa25c2f55298a@lixom.net>
Signed-off-by: Lee Jones <630e34333487a351a857f6b705e04d30b37c1629@linaro.org>

KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs