gpio: Add viperboard gpio driver

This adds the mfd cell to use the gpio a and gpio b part
of the Nano River Technologies viperboard.

Signed-off-by: Lars Poeschel <poeschel@lemonage.de>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>

1 files changed, 13 insertions, 0 deletions

diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
index d055cee36942..c3bbd08bcdc3 100644
--- a/drivers/gpio/Kconfig
+++ b/drivers/gpio/Kconfig
@@ -649,4 +649,17 @@ config GPIO_MSIC
           Enable support for GPIO on intel MSIC controllers found in
           intel MID devices
 
+comment "USB GPIO expanders:"
+
+config GPIO_VIPERBOARD
+        tristate "Viperboard GPIO a & b support"
+        depends on MFD_VIPERBOARD && USB
+        help
+          Say yes here to access the GPIO signals of Nano River
+          Technologies Viperboard. There are two GPIO chips on the
+          board: gpioa and gpiob.
+          See viperboard API specification and Nano
+          River Tech's viperboard.h for detailed meaning
+          of the module parameters.
+
 endif