iio: light: Add driver for Silabs si1132, si1141/2/3 and si1145/6/7 ambient light, uv index and proximity sensors

The si114x supports x=1,2,3 IR LEDs for proximity sensing together with
visible and IR ambient light sensing (ALS).

Newer parts (si1132, si1145/6/7) can measure UV light and compute an UV
index
This was tested on si1143 and si1145

Signed-off-by: Peter Meerwald-Stadler <pmeerw@pmeerw.net>
Signed-off-by: Crestez Dan Leonard <leonard.crestez@intel.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

drivers/iio/light/Kconfig

@@ -267,6 +267,19 @@ config PA12203001
          This driver can also be built as a module.  If so, the module
          will be called pa12203001.
 
+config SI1145
+	tristate "SI1132 and SI1141/2/3/5/6/7 combined ALS, UV index and proximity sensor"
+	depends on I2C
+	select IIO_BUFFER
+	select IIO_TRIGGERED_BUFFER
+	help
+	  Say Y here if you want to build a driver for the Silicon Labs SI1132 or
+	  SI1141/2/3/5/6/7 combined ambient light, UV index and proximity sensor
+	  chips.
+
+	  To compile this driver as a module, choose M here: the module will be
+	  called si1145.
+
 config STK3310
 	tristate "STK3310 ALS and proximity sensor"
 	depends on I2C

drivers/iio/light/Makefile

@@ -26,6 +26,7 @@ obj-$(CONFIG_OPT3001)		+= opt3001.o
 obj-$(CONFIG_PA12203001)	+= pa12203001.o
 obj-$(CONFIG_RPR0521)		+= rpr0521.o
 obj-$(CONFIG_SENSORS_TSL2563)	+= tsl2563.o
+obj-$(CONFIG_SI1145)		+= si1145.o
 obj-$(CONFIG_STK3310)          += stk3310.o
 obj-$(CONFIG_TCS3414)		+= tcs3414.o
 obj-$(CONFIG_TCS3472)		+= tcs3472.o