mfd: Introduce retu-mfd driver

Retu is a multi-function device found on Nokia Internet Tablets
implementing at least watchdog, RTC, headset detection and power button
functionality.

This patch implements minimum functionality providing register access,
IRQ handling and power off functions.

Acked-by: Felipe Balbi <balbi@ti.com>
Acked-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Aaro Koskinen <aaro.koskinen@iki.fi>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>

1 files changed, 9 insertions, 0 deletions

diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
index ca633df7c330..f5b839b718aa 100644
--- a/drivers/mfd/Kconfig
+++ b/drivers/mfd/Kconfig
@@ -1094,6 +1094,15 @@ config MFD_VIPERBOARD
           You need to select the mfd cell drivers separately.
           The drivers do not support all features the board exposes.
 
+config MFD_RETU
+        tristate "Support for Retu multi-function device"
+        select MFD_CORE
+        depends on I2C
+        select REGMAP_IRQ
+        help
+          Retu is a multi-function device found on Nokia Internet Tablets
+          (770, N800 and N810).
+
 endmenu
 endif