iio: adc: Add rtq6056 support

Add Richtek rtq6056 supporting.

It can be used for the system to monitor load current and power with 16-bit
resolution.
Signed-off-by: ChiYuan Huang <cy_huang@richtek.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Link: https://lore.kernel.org/r/1658242365-27797-3-git-send-email-u0084500@gmail.comSigned-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

drivers/iio/adc/Kconfig

@@ -919,6 +919,21 @@ config ROCKCHIP_SARADC
 	  To compile this driver as a module, choose M here: the
 	  module will be called rockchip_saradc.
 
+config RICHTEK_RTQ6056
+	tristate "Richtek RTQ6056 Current and Power Monitor ADC"
+	depends on I2C
+	select REGMAP_I2C
+	select IIO_BUFFER
+	select IIO_TRIGGERED_BUFFER
+	help
+	  Say yes here to enable RQT6056 ADC support.
+	  RTQ6056 is a high accuracy current-sense monitor with I2C and SMBus
+	  compatible interface, and the device provides full information for
+	  system by reading out the load current and power.
+
+	  This driver can also be built as a module. If so, the module will be
+	  called rtq6056.
+
 config RZG2L_ADC
 	tristate "Renesas RZ/G2L ADC driver"
 	depends on ARCH_RZG2L || COMPILE_TEST

drivers/iio/adc/Makefile

@@ -85,6 +85,7 @@ obj-$(CONFIG_QCOM_PM8XXX_XOADC) += qcom-pm8xxx-xoadc.o
 obj-$(CONFIG_RCAR_GYRO_ADC) += rcar-gyroadc.o
 obj-$(CONFIG_RN5T618_ADC) += rn5t618-adc.o
 obj-$(CONFIG_ROCKCHIP_SARADC) += rockchip_saradc.o
+obj-$(CONFIG_RICHTEK_RTQ6056) += rtq6056.o
 obj-$(CONFIG_RZG2L_ADC) += rzg2l_adc.o
 obj-$(CONFIG_SC27XX_ADC) += sc27xx_adc.o
 obj-$(CONFIG_SPEAR_ADC) += spear_adc.o