tree 863f5b79177c3e0bbb3b35268edb190d8acfe8fb
parent a7ff477bb7e5ec9536e8aac02e8856a4bcc595a3
author Maxime Ripard <maxime.ripard@free-electrons.com> 1347309339 +0200
committer Linus Walleij <linus.walleij@linaro.org> 1347400172 +0200

gpio: 74x164: Add support for the daisy-chaining

The shift registers have an output pin that, when enabled, propagates
the values of its internal register to the pins. If another value comes
to the register while the output pin is disabled, this new value will
makae the older shift into the next register in the chain.

This patch adds support for daisy-chaining the registers, using the
regular SPI chip select mechanism to manage the output pin, and the
registers-number dt property to set the number of chained registers.

Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>