Some WLAN chips attached to a SDIO interface, need an external clock
to be operational. Since this is very common, extend the simple MMC
power sequence DT binding to support an optional clock.
Signed-off-by: Javier Martinez Canillas <javier.martinez@collabora.co.uk>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Many SDIO/MMC attached WLAN chips need more than one ping for their reset
sequence. Extend the pwrseq_simple binding to support more than one pin.
Signed-off-by: Javier Martinez Canillas <javier.martinez@collabora.co.uk>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
To support SOCs which specifies specific MMC power sequences, document
some MMC DT bindings to be able to describe these hardwares.
Let's also document bindings for a simple MMC power sequence provider,
which purpose is to support a set of common properties between various
SOCs.
In this initial step, let's also document a top level description of
the MMC power sequence and describe the compatible string used for the
simple MMC power sequence provider.
The simple MMC power sequence provider will initially support a reset
GPIO. From several earlier posted patches, it's clear that such
hardware exists. Especially some WLAN chips which are attached to an
SDIO interface may use a GPIO reset.
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Tested-by: Javier Martinez Canillas <javier.martinez@collabora.co.uk>
Reviewed-by: Javier Martinez Canillas <javier.martinez@collabora.co.uk>
