iio: adc: Add imx25-gcq ADC driver

This is a conversion queue driver for the mx25 SoC. It uses the central
ADC which is used by two seperate independent queues. This driver
prepares different conversion configurations for each possible input.
For a conversion it creates a conversionqueue of one item with the
correct configuration for the chosen channel. It then executes the queue
once and disables the conversion queue afterwards.

The reference voltages are configurable through devicetree subnodes,
depending on the connections of the ADC inputs.
Signed-off-by: Markus Pargmann <mpa@pengutronix.de>
Signed-off-by: Denis Carikli <denis@eukrea.com>
Acked-by: Jonathan Cameron <jic23@kernel.org>
Signed-off-by: Lee Jones <lee.jones@linaro.org>

drivers/iio/adc/Kconfig

@@ -183,6 +183,13 @@ config EXYNOS_ADC
 	  To compile this driver as a module, choose M here: the module will be
 	  called exynos_adc.
 
+config FSL_MX25_ADC
+	tristate "Freescale MX25 ADC driver"
+	depends on MFD_MX25_TSADC
+	help
+	  Generic Conversion Queue driver used for general purpose ADC in the
+	  MX25. This driver supports single measurements using the MX25 ADC.
+
 config HI8435
 	tristate "Holt Integrated Circuits HI-8435 threshold detector"
 	select IIO_TRIGGERED_EVENT

drivers/iio/adc/Makefile

@@ -19,6 +19,7 @@ obj-$(CONFIG_BERLIN2_ADC) += berlin2-adc.o
 obj-$(CONFIG_CC10001_ADC) += cc10001_adc.o
 obj-$(CONFIG_DA9150_GPADC) += da9150-gpadc.o
 obj-$(CONFIG_EXYNOS_ADC) += exynos_adc.o
+obj-$(CONFIG_FSL_MX25_ADC) += fsl-imx25-gcq.o
 obj-$(CONFIG_HI8435) += hi8435.o
 obj-$(CONFIG_IMX7D_ADC) += imx7d_adc.o
 obj-$(CONFIG_INA2XX_ADC) += ina2xx-adc.o