iio: light: Add support for APDS9306 Light Sensor

Driver support for Avago (Broadcom) APDS9306 Ambient Light Sensor.
It has two channels - ALS and CLEAR. The ALS (Ambient Light Sensor)
channel approximates the response of the human-eye providing direct
read out where the output count is proportional to ambient light levels.
It is internally temperature compensated and rejects 50Hz and 60Hz flicker
caused by artificial light sources. Hardware interrupt configuration is
optional. It is a low power device with 20 bit resolution and has
configurable adaptive interrupt mode and interrupt persistence mode.
The device also features inbuilt hardware gain, multiple integration time
selection options and sampling frequency selection options.

This driver also uses the IIO GTS (Gain Time Scale) Helpers Namespace for
Scales, Gains and Integration time implementation.

Signed-off-by: Subhajit Ghosh <subhajit.ghosh@tweaklogic.com>
Link: https://lore.kernel.org/r/20240309105031.10313-6-subhajit.ghosh@tweaklogic.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

drivers/iio/light/Kconfig

@@ -73,6 +73,18 @@ config APDS9300
 	  To compile this driver as a module, choose M here: the
 	  module will be called apds9300.
 
+config APDS9306
+	tristate "Avago APDS9306 Ambient Light Sensor"
+	depends on I2C
+	select REGMAP_I2C
+	select IIO_GTS_HELPER
+	help
+	  If you say Y or M here, you get support for Avago APDS9306
+	  Ambient Light Sensor.
+
+	  If built as a dynamically linked module, it will be called
+	  apds9306.
+
 config APDS9960
 	tristate "Avago APDS9960 gesture/RGB/ALS/proximity sensor"
 	select REGMAP_I2C

drivers/iio/light/Makefile

@@ -10,6 +10,7 @@ obj-$(CONFIG_ADUX1020)		+= adux1020.o
 obj-$(CONFIG_AL3010)		+= al3010.o
 obj-$(CONFIG_AL3320A)		+= al3320a.o
 obj-$(CONFIG_APDS9300)		+= apds9300.o
+obj-$(CONFIG_APDS9306)		+= apds9306.o
 obj-$(CONFIG_APDS9960)		+= apds9960.o
 obj-$(CONFIG_AS73211)		+= as73211.o
 obj-$(CONFIG_BH1750)		+= bh1750.o