Re: [PATCH 2/2] DT: iio: vadc: document dt binding

[Hartmut Knaack <knaack.h-Mmb7MZpHnFY@public.gmane.org>]

Stanimir Varbanov schrieb, Am 05.09.2014 14:14:
> Document DT binding for Qualcomm SPMI PMIC voltage ADC
> driver.
> 
> Signed-off-by: Stanimir Varbanov <svarbanov-NEYub+7Iv8PQT0dZR+AlfA@public.gmane.org>
> Signed-off-by: Ivan T. Ivanov <iivanov-NEYub+7Iv8PQT0dZR+AlfA@public.gmane.org>
> ---
>  .../devicetree/bindings/iio/adc/qcom,spmi-vadc.txt |  110 ++++++++++++++++++++
>  1 files changed, 110 insertions(+), 0 deletions(-)
>  create mode 100644 Documentation/devicetree/bindings/iio/adc/qcom,spmi-vadc.txt
> 
> diff --git a/Documentation/devicetree/bindings/iio/adc/qcom,spmi-vadc.txt b/Documentation/devicetree/bindings/iio/adc/qcom,spmi-vadc.txt
> new file mode 100644
> index 0000000..f9c780f
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/iio/adc/qcom,spmi-vadc.txt
> @@ -0,0 +1,110 @@
> +Qualcomm's SPMI PMIC voltage ADC
> +
> +SPMI PMIC voltage ADC (VADC) provides interface to clients to read
> +voltage. A 15 bit ADC is used for voltage measurements. There are multiple
> +peripherals to the VADC and the scope of the driver is to provide interface
> +for the USR peripheral of the VADC.
> +
> +VADC node:
> +
> +- compatible:
> +    Usage: required
> +    Value type: <string>
> +    Definition: Should contain "qcom,spmi-vadc".
> +
> +- reg:
> +    Usage: required
> +    Value type: <u32>
> +    Definition: Base address in the SPMI PMIC register map.
> +
> +- interrupts:
> +    Usage: required
> +    Value type: <prop-encoded-array>
> +    Definition: End of convertion interrupt number.
Typo: conversion
> +
> +- qcom,poll-eoc:
> +    Usage: optional
> +    Value type: <empty>
> +    Definition: Use polling instead of interrupt for end of conversion
> +            completion.
> +
> +Channel node properities:
Typo: properties
> +
> +- qcom,channel:
> +    Usage: required
> +    Value type: <u32>
> +    Definition: AMUX channel number.
> +
> +- qcom,decimation:
> +    Usage: optional
> +    Value type: <u32>
> +    Definition: Sampling rate to use for the individual channel measurement.
> +            Quicker measurements can be made by reducing decimation ratio.
> +            Valid values are 512, 1024, 2048, 4096.
> +            If property is not found, default value of 512 will be used.
> +
> +- qcom,pre-scaling:
> +    Usage: optional
> +    Value type: <u32 array>
> +    Definition: Used for scaling the channel input signal before the signal is
> +            fed to VADC. The configuration for this node is to know the
> +            pre-determined ratio and use it for post scaling. Select one from
> +            the following options.
> +            <1 1>, <1 3>, <1 4>, <1 6>, <1 20>, <1 8>, <10 81>, <1 10>
> +            If property is not found default value depending of chip will be used.
> +
> +- qcom,ratiometric:
> +    Usage: optional
> +    Value type: <empty>
> +    Definition: Channel calibration type. If this property is specified
> +            VADC will use the VDD reference(1.8V) and GND for channel
> +            calibration. If properity is not found, channel will be
Typo: property
> +            calibrated with 625mv and 1.25V reference channels.
> +
> +- qcom,hw-settle-time:
> +    Usage: optional
> +    Value type: <u32>
> +    Definition: Time between AMUX getting configured and the ADC starting
> +            conversion. Delay = 100us * (value) for value < 11, and
> +            2ms * (value - 10) otherwise.
> +            Valid values are: 0, 100, 200, 300, 400, 500, 600, 700, 800,
> +            900 us and 1, 2, 4, 6, 8, 10 ms
> +            If property is not found, channel will use 0us.
> +
> +- qcom,avg-samples:
> +    Usage: optional
> +    Value type: <u32>
> +    Definition: Number of samples to be used for measurement.
> +            Fast averaging provides the option to obtain a single measurement
> +            from the ADC that is an average of multiple samples. The value
> +            selected is 2^(value).
> +            Valid values are: 1, 2, 4, 8, 16, 32, 64, 128, 256, 512
> +            If property is not found, 1 sample will be used.
> +
> +- label:
> +    Usage: optional
> +    Value type: <string>
> +    Definition: Channel name used for sysfs entry. If not provided
> +            configuration device node name will be used.
> +
> +NOTE: At least one channel node is required.
> +
> +Example:
> +	/* VADC node */
> +	vadc@3100 {
> +		compatible = "qcom,spmi-vadc";
> +		reg = <0x3100>;
> +		interrupts = <0x0 0x31 0x0 IRQ_TYPE_EDGE_RISING>;
> +		#io-channel-cells = <1>;
> +		io-channel-ranges;
> +
> +		/* Channel node */
> +		usb_id_nopull@39 {
> +			qcom,channel = <VADC_LR_MUX10_USB_ID>;
> +			qcom,decimation = <512>;
> +			qcom,ratiometric;
> +			qcom,hw-settle-time = <200>;
> +			qcom,avg-samples = <1>;
> +			qcom,pre-scaling = <1 3>
> +		};
> +	};
>