From: Stephen Warren <swarren@nvidia.com>
Date: Tue, 6 Mar 2012 00:22:15 +0000 (-0700)
Subject: pinctrl: allow concurrent gpio and mux function ownership of pins
X-Git-Tag: v3.4-rc1~128^2~5
X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=652162d469a73450a66b6c8049b16c2b7828fa24;p=pandora-kernel.git

pinctrl: allow concurrent gpio and mux function ownership of pins

Per recent updates to Documentation/gpio.txt, gpiolib drivers should
inform pinctrl when a GPIO is requested. pinctrl then marks that pin as
in-use for that GPIO function.

When an SoC muxes pins in a group, it's quite possible for the group to
contain e.g. 6 pins, but only 4 of them actually be needed by the HW
module that's mux'd to them. In this case, the other 2 pins could be
used as GPIOs. However, pinctrl marks all the pins within the group as
in-use by the selected mux function. To allow the expected gpiolib
interaction, separate the concepts of pin ownership into two parts: One
for the mux function and one for GPIO usage. Finally, allow those two
ownerships to exist in parallel.

Signed-off-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
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