Some devices need a while to boot their firmware after providing clks /
de-asserting resets before they are ready to receive sdio commands.

This commits adds a post-power-on-delay-ms devicetree property to
mmc-pwrseq-simple for use with such devices.
Signed-off-by: NHans de Goede <hdegoede@redhat.com>
Acked-by: NRob Herring <robh@kernel.org>
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>

Signed-off-by: NAndreas Fenkart <afenkart@gmail.com>
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>

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: NJavier Martinez Canillas <javier.martinez@collabora.co.uk>
Signed-off-by: NUlf 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: NJavier Martinez Canillas <javier.martinez@collabora.co.uk>
Signed-off-by: NUlf 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: NUlf Hansson <ulf.hansson@linaro.org>
Tested-by: NJavier Martinez Canillas <javier.martinez@collabora.co.uk>
Reviewed-by: NJavier Martinez Canillas <javier.martinez@collabora.co.uk>