iio: adc: add support for Berlin

This patch adds the support of the Berlin ADC, available on Berlin SoCs.
This ADC has 8 channels available, with one connected to a temperature
sensor.

The particularity here, is that the temperature sensor connected to the
ADC has its own registers, and both the ADC and the temperature sensor
must be configured when using it.
Signed-off-by: Antoine Tenart <antoine.tenart@free-electrons.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

drivers/iio/adc/Kconfig

@@ -135,6 +135,13 @@ config AXP288_ADC
 	  device. Depending on platform configuration, this general purpose ADC can
 	  be used for sampling sensors such as thermal resistors.
 
+config BERLIN2_ADC
+	tristate "Marvell Berlin2 ADC driver"
+	depends on ARCH_BERLIN
+	help
+	  Marvell Berlin2 ADC driver. This ADC has 8 channels, with one used for
+	  temperature measurement.
+
 config DA9150_GPADC
 	tristate "Dialog DA9150 GPADC driver support"
 	depends on MFD_DA9150

drivers/iio/adc/Makefile

@@ -15,6 +15,7 @@ obj-$(CONFIG_AD7887) += ad7887.o
 obj-$(CONFIG_AD799X) += ad799x.o
 obj-$(CONFIG_AT91_ADC) += at91_adc.o
 obj-$(CONFIG_AXP288_ADC) += axp288_adc.o
+obj-$(CONFIG_BERLIN2_ADC) += berlin2-adc.o
 obj-$(CONFIG_DA9150_GPADC) += da9150-gpadc.o
 obj-$(CONFIG_CC10001_ADC) += cc10001_adc.o
 obj-$(CONFIG_EXYNOS_ADC) += exynos_adc.o