mfd: atmel-flexcom: Add a driver for Atmel Flexible Serial Communication Unit

This driver supports the new Atmel Flexcom. The Flexcom is a wrapper which
integrates one SPI controller, one I2C controller and one USART. Only one
function can be enabled at a time. This driver selects the function once
for all, when the Flexcom is probed, according to the value of the new
"atmel,flexcom-mode" device tree property.

This driver has chosen to present the Flexcom to the system as a MFD so
the implementation is seamless for the existing Atmel SPI, I2C and USART
drivers.

Also the Flexcom embeds FIFOs: the latest patches of the SPI, I2C and
USART drivers take advantage of this new feature.

Signed-off-by: Cyrille Pitchen <cyrille.pitchen@atmel.com>
Acked-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Acked-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>

1 files changed, 11 insertions, 0 deletions

diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
index 99d63675f073..87e84e7c71da 100644
--- a/drivers/mfd/Kconfig
+++ b/drivers/mfd/Kconfig
@@ -60,6 +60,17 @@ config MFD_AAT2870_CORE
           additional drivers must be enabled in order to use the
           functionality of the device.
 
+config MFD_ATMEL_FLEXCOM
+        tristate "Atmel Flexcom (Flexible Serial Communication Unit)"
+        select MFD_CORE
+        depends on OF
+        help
+          Select this to get support for Atmel Flexcom. This is a wrapper
+          which embeds a SPI controller, a I2C controller and a USART. Only
+          one function can be used at a time. The choice is done at boot time
+          by the probe function of this MFD driver according to a device tree
+          property.
+
 config MFD_ATMEL_HLCDC
         tristate "Atmel HLCDC (High-end LCD Controller)"
         select MFD_CORE