tree 00722e622de49da9fa748f0d02762f74d47b3fb5
parent a0e637387a9858f9c2e8228bc15e299387dadcd1
author Linus Walleij <linus.walleij@linaro.org> 1459867797 +0200
committer Linus Walleij <linus.walleij@linaro.org> 1460225666 +0200

gpio: document open drain/source behaviour

This has been a totally undocumented feature for years so add some
generic concepts and documentation about open drain/source, include
some facts on how we now support for hardware.

Cc: Michael Hennerich <michael.hennerich@analog.com>
Cc: Nicolas Saenz Julienne <nicolassaenzj@gmail.com>
Cc: H. Nikolaus Schaller <hns@goldelico.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>