Commit 33ec3e5f authored by Marius Cristea's avatar Marius Cristea Committed by Jonathan Cameron
Browse files

iio: adc: adding support for MCP3564 ADC 



This is the iio driver for Microchip family of 153.6 ksps,
Low-Noise 16/24-Bit Delta-Sigma ADCs with an SPI interface
(Microchip's  MCP3461, MCP3462, MCP3464, MCP3461R, MCP3462R,
MCP3464R, MCP3561, MCP3562, MCP3564, MCP3561R,
MCP3562R and MCP3564R analog to digital converters).

Signed-off-by: default avatarMarius Cristea <marius.cristea@microchip.com>
Link: https://lore.kernel.org/r/20230829154133.40716-3-marius.cristea@microchip.com


Signed-off-by: default avatarJonathan Cameron <Jonathan.Cameron@huawei.com>
parent df2ece7a

Documentation/ABI/testing/sysfs-bus-iio-adc-mcp3564

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What:		/sys/bus/iio/devices/iio:deviceX/boost_current_gain

KernelVersion:	6.4

Contact:	linux-iio@vger.kernel.org

Description:

		This attribute is used to set the gain of the biasing current

		circuit of the Delta-Sigma modulator. The different BOOST

		settings are applied to the entire modulator circuit, including

		the voltage reference buffers.



What:		/sys/bus/iio/devices/iio:deviceX/boost_current_gain_available

KernelVersion:	6.4

Contact:	linux-iio@vger.kernel.org

Description:

		Reading returns a list with the possible gain values for

		the current biasing circuit of the Delta-Sigma modulator.



What:		/sys/bus/iio/devices/iio:deviceX/auto_zeroing_mux_enable

KernelVersion:	6.4

Contact:	linux-iio@vger.kernel.org

Description:

		This attribute is used to enable the analog input multiplexer

		auto-zeroing algorithm (the input multiplexer and the ADC

		include an offset cancellation algorithm that cancels the offset

		contribution of the ADC). When the offset cancellation algorithm

		is enabled, ADC takes two conversions, one with the differential

		input as VIN+/VIN-, one with VIN+/VIN- inverted. In this case the

		conversion time is multiplied by two compared to the default

		case where the algorithm is disabled. This technique allows the

		cancellation of the ADC offset error and the achievement of

		ultra-low offset without any digital calibration. The resulting

		offset is the residue of the difference between the two

		conversions, which is on the order of magnitude of the noise

		floor. This offset is effectively canceled at every conversion,

		so the residual offset error temperature drift is extremely low.

		Write '1' to enable it, write '0' to disable it.



What:		/sys/bus/iio/devices/iio:deviceX/auto_zeroing_ref_enable

KernelVersion:	6.4

Contact:	linux-iio@vger.kernel.org

Description:

		This attribute is used to enable the chopping algorithm for the

		internal voltage reference buffer. This setting has no effect

		when external voltage reference is selected.

		Internal voltage reference buffer injects a certain quantity of

		1/f noise into the system that can be modulated with the

		incoming input signals and can limit the SNR performance at

		higher Oversampling Ratio values (over 256). To overcome this

		limitation, the buffer includes an auto-zeroing algorithm that

		greatly reduces (cancels out) the 1/f noise and cancels the

		offset value of the reference buffer. As a result, the SNR of

		the system is not affected by this 1/f noise component of the

		reference buffer, even at maximum oversampling ratio values.

		Write '1' to enable it, write '0' to disable it.

MAINTAINERS

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@@ -14019,6 +14019,13 @@ S: Supported 
F:	Documentation/devicetree/bindings/regulator/mcp16502-regulator.txt

F:	drivers/regulator/mcp16502.c









MICROCHIP MCP3564 ADC DRIVER









M:      Marius Cristea <marius.cristea@microchip.com>









L:      linux-iio@vger.kernel.org









S:      Supported









F:      Documentation/devicetree/bindings/iio/adc/microchip,mcp3564.yaml









F:      drivers/iio/adc/mcp3564.c

















MICROCHIP MCP3911 ADC DRIVER









M:	Marcus Folkesson <marcus.folkesson@gmail.com>









M:	Kent Gustavsson <kent@minoris.se>
































drivers/iio/adc/Kconfig



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@@ -789,6 +789,19 @@ config MCP3422







	  This driver can also be built as a module. If so, the module will be









	  called mcp3422.



















config MCP3564









        tristate "Microchip Technology MCP3461/2/4/R, MCP3561/2/4/R driver"









        depends on SPI









        depends on IIO









        help









          Say yes here to build support for Microchip Technology's MCP3461,









          MCP3462, MCP3464, MCP3461R, MCP3462R, MCP3464R, MCP3561, MCP3562,









          MCP3564, MCP3561R, MCP3562R and MCP3564R analog to digital









          converters.



















          This driver can also be built as a module. If so, the module will be









          called mcp3564.



















config MCP3911









	tristate "Microchip Technology MCP3911 driver"









	depends on SPI
































drivers/iio/adc/Makefile



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@@ -72,6 +72,7 @@ obj-$(CONFIG_MAX77541_ADC) += max77541-adc.o







obj-$(CONFIG_MAX9611) += max9611.o









obj-$(CONFIG_MCP320X) += mcp320x.o









obj-$(CONFIG_MCP3422) += mcp3422.o









obj-$(CONFIG_MCP3564) += mcp3564.o









obj-$(CONFIG_MCP3911) += mcp3911.o









obj-$(CONFIG_MEDIATEK_MT6360_ADC) += mt6360-adc.o









obj-$(CONFIG_MEDIATEK_MT6370_ADC) += mt6370-adc.o
































drivers/iio/adc/mcp3564.c
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