[PATCH 1/3 v2] iio: adc: add device tree bindings for Qualcomm PM8xxx ADCs
From: robh@kernel.org (Rob Herring)
Date: 2016-12-19 22:50:38
Also in:
linux-arm-msm, linux-devicetree, linux-iio
On Thu, Dec 15, 2016 at 11:48:09PM +0100, Linus Walleij wrote:
quoted hunk
This adds the device tree bindings for the Qualcomm PM8xxx ADCs. This is based on the existing DT bindings for the SPMI ADC so there are hopefully no controversial features. Cc: devicetree at vger.kernel.org Cc: linux-arm-kernel at lists.infradead.org Cc: linux-arm-msm at vger.kernel.org Cc: Ivan T. Ivanov <redacted> Cc: Andy Gross <redacted> Cc: Bjorn Andersson <redacted> Cc: Stephen Boyd <redacted> Cc: Srinivas Kandagatla <redacted> Signed-off-by: Linus Walleij <redacted> --- ChangeLog v1->v2: - Spelling fixes --- .../bindings/iio/adc/qcom,pm8xxx-xoadc.txt | 160 +++++++++++++++++++++ 1 file changed, 160 insertions(+) create mode 100644 Documentation/devicetree/bindings/iio/adc/qcom,pm8xxx-xoadc.txtdiff --git a/Documentation/devicetree/bindings/iio/adc/qcom,pm8xxx-xoadc.txt b/Documentation/devicetree/bindings/iio/adc/qcom,pm8xxx-xoadc.txt new file mode 100644 index 000000000000..3c6bca5b4edf --- /dev/null +++ b/Documentation/devicetree/bindings/iio/adc/qcom,pm8xxx-xoadc.txt@@ -0,0 +1,160 @@ +Qualcomm's PM8xxx voltage XOADC + +The Qualcomm PM8xxx PMICs contain a HK/XO ADC (Housekeeping/Crystal +oscillator ADC) encompassing PM8018, PM8038, PM8058, PM8917 and PM8921. + +Required properties: + +- compatible: should be one of: + "qcom,pm8018-adc" + "qcom,pm8038-adc" + "qcom,pm8058-adc" + "qcom,pm8917-adc" + "qcom,pm8921-adc" + +- reg: should contain the ADC base address in the PMIC, typically + 0x197. + +The following required properties are standard for IO channels, see +iio-bindings.txt for more details: + +- #address-cells: should be set to <1> + +- #size-cells: should be set to <0> + +- #io-channel-cells: should be set to <1> + +- interrupts: should refer to the parent PMIC interrupt controller + and reference the proper ADC interrupt. + +Required subnodes: + +The ADC channels are configured as subnodes of the ADC. Since some of +them are used for calibrating the ADC, these nodes are compulsory: + +ref_625mv {
ref at c
+ reg = <0x0c>;
+};
+
+ref_1250mv {
+ reg = <0x0d>;
+};
+
+ref_muxoff {
+ reg = <0x0f>;
+};
+
+These three nodes are used for absolute and ratiometric calibration
+and only need to have these reg values: they are by hardware definition
+1:1 ratio converters that sample 625, 1250 and 0 milliV and create
+an interpolation calibration for all other ADCs.
+
+Optional subnodes: any channels other than channel 0x0c, 0x0d and
+0x0f are optional.
+
+Required channel node properties:
+
+- reg: should contain the hardware channel number in the range
+ 0 .. 0x0f (4 bits). The hardware only supports 16 channels.
+
+Optional channel node properties:
+
+- qcom,decimation:
+ Value type: <u32>
+ Definition: This parameter is used to decrease the ADC sampling rate.
+ Quicker measurements can be made by reducing the decimation ratio.
+ Valid values are 512, 1024, 2048, 4096.
+ If the property is not found, a default value of 512 will be used.
+
+- qcom,ratiometric:
+ 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 the property is not found, the channel will be
+ calibrated with the 0.625V and 1.25V reference channels, also
+ known as an absolute calibration.
+
+- qcom,ratiometric-ref:
+ Value type: <u32>
+ Definition: The reference voltage pair when using ratiometric
+ calibration:
+ 0 = XO_IN/XOADC_GND
+ 1 = PMIC_IN/XOADC_GND
+ 2 = PMIC_IN/BMS_CSP
+ 3 (invalid)
+ 4 = XOADC_GND/XOADC_GND
+ 5 = XOADC_VREF/XOADC_GND
+
+Example:
+
+xoadc: xoadc at 197 {
+ compatible = "qcom,pm8058-adc";
+ reg = <0x197>;
+ interrupt-parent = <&pm8058>;
+ interrupts = <76 1>;
+ #address-cells = <1>;
+ #size-cells = <0>;
+ #io-channel-cells = <1>;
+
+ vcoin {
+ reg = <0x00>;If you have a reg property, then you should have a unit address on all of these. These should really all be something like adc-channel at ... Not sure if we have a standard node name for ADC channels. Or don't put any of this in DT.
+ };
+ vbat {
+ reg = <0x01>;
+ };
+ dcin {
+ reg = <0x02>;
+ };
+ ichg {
+ reg = <0x03>;
+ };
+ vph_pwr {
+ reg = <0x04>;
+ };
+ mpp5 {
+ reg = <0x05>;
+ };
+ mpp6 {
+ reg = <0x06>;
+ };
+ mpp7 {
+ reg = <0x07>;
+ };
+ mpp8 {
+ reg = <0x08>;
+ };
+ mpp9 {
+ reg = <0x09>;
+ };
+ usb_vbus {
+ reg = <0x0a>;
+ };
+ die_temp {
+ reg = <0x0b>;
+ };
+ ref_625mv {
+ reg = <0x0c>;
+ };
+ ref_1250mv {
+ reg = <0x0d>;
+ };
+ ref_325mv {
+ reg = <0x0e>;
+ };
+ ref_muxoff {
+ reg = <0x0f>;
+ };
+};