[PATCH v3 1/2] dt-bindings: iio: adc: add support for PAC1711
From: Ariana Lazar
Date: Wed Sep 09 2026 - 08:36:58 EST
This is the device tree schema for Microchip PAC1711, PAC1721, PAC1811 and
PAC1821 single-channel power monitor with accumulator. The PAC1711 and
PAC1721 devices use 12-bit resolution for voltage and current measurements
and 24 bits for power calculations, while PAC1811 and PAC1821 have 16-bit
resolution and use 32 bits for power calculations. The 56-bit accumulator
register accumulates power (energy) or current (Coulomb counter).
PAC1711 and PAC1811 measure up to 42V Full-Scale Range, respectively 9V for
PAC1721 and PAC1821.
Signed-off-by: Ariana Lazar <ariana.lazar@xxxxxxxxxxxxx>
---
.../bindings/iio/adc/microchip,pac1711.yaml | 183 +++++++++++++++++++++
MAINTAINERS | 6 +
2 files changed, 189 insertions(+)
diff --git a/Documentation/devicetree/bindings/iio/adc/microchip,pac1711.yaml b/Documentation/devicetree/bindings/iio/adc/microchip,pac1711.yaml
new file mode 100644
index 0000000000000000000000000000000000000000..c10b4b83a08d690b8045a3f42d4e43d17a8058d7
--- /dev/null
+++ b/Documentation/devicetree/bindings/iio/adc/microchip,pac1711.yaml
@@ -0,0 +1,183 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/iio/adc/microchip,pac1711.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Microchip PAC1711 Power Monitors with Accumulator
+
+maintainers:
+ - Ariana Lazar <ariana.lazar@xxxxxxxxxxxxx>
+
+description: |
+ This device is part of the Microchip family of Power Monitors with Accumulator.
+ Datasheet links:
+ [PAC1711]: https://ww1.microchip.com/downloads/aemDocuments/documents/MSLD/ProductDocuments/PAC1711-Data-Sheet-DS20007058.pdf
+ [PAC1721]: https://ww1.microchip.com/downloads/aemDocuments/documents/MSLD/ProductDocuments/PAC1721-Single-Channel-Power-Monitor-with-Accumulator-DS20007088.pdf
+ [PAC1811]: https://ww1.microchip.com/downloads/aemDocuments/documents/MSLD/ProductDocuments/DataSheets/PAC1811-Data-Sheet-DS20007066.pdf
+ [PAC1821]: https://ww1.microchip.com/downloads/aemDocuments/documents/MSLD/ProductDocuments/DataSheets/PAC1821-Data-Sheet-DS20007097.pdf
+
+ PAC1711, PAC1721, PAC1811 and PAC1821 are Single Channel Power Monitors
+ with Accumulator, having 12-bit or 16-bit resolution. The devices PAC1711
+ and PAC1811 can measure up to 42V Full-Scale Range, respectively 9V
+ Full-Scale Range for PAC1721 and PAC1821.
+
+ The accumulation-source property aims to specify what kind of hardware is
+ intended to be used/available for the user. There are two main cases here:
+ - the user wants to measure also the current/power consumed before the
+ driver insertion (e.g. from the boot to user control) and if this is a
+ runtime setting, the hardware accumulator will be reset by the default
+ configuration the driver starts with.
+ - the driver does not know what type of hardware it's dealing with. In
+ case the part is monitoring the charge/discharge current it does not
+ make sense in user-space to change the accumulator to calculate energy.
+ Same if the hardware is intended to calculate energy it does not make
+ sense in user-space to change to Coulomb counter. Changing the setting
+ from one mode to another will reset the hardware accumulator inside the
+ chip.
+
+properties:
+ compatible:
+ enum:
+ - microchip,pac1711
+ - microchip,pac1721
+ - microchip,pac1811
+ - microchip,pac1821
+
+ reg:
+ maxItems: 1
+
+ vdd-supply: true
+
+ "#io-channel-cells":
+ const: 1
+
+ shunt-resistor-micro-ohms:
+ description:
+ Value in micro Ohms of the shunt resistor connected between the VSENSE+
+ and VSENSE- inputs, across which the current is measured. This value is
+ needed to compute the scaling of the measured current.
+
+ label:
+ description: Unique name to identify which device this is.
+
+ microchip,vbus-input-range-microvolt:
+ description: |
+ Specifies the voltage range in microvolts chosen for the voltage full
+ scale range (FSR). The range should be set as <minimum, maximum> by
+ hardware design and should not be changed during runtime.
+
+ The VBUS could be configured into the following full scale range:
+ - for PAC1711 or PAC1811:
+ - VBUS has unipolar 0V to 42V FSR (default)
+ - VBUS has bipolar -42V to 42V FSR
+ - VBUS has bipolar -21V to 21V FSR
+ - for PAC1721 or PAC1821:
+ - VBUS has unipolar 0V to 9V FSR (default)
+ - VBUS has bipolar -9V to 9V FSR
+ - VBUS has bipolar -4.5V to 4.5V FSR
+
+ microchip,vsense-input-range-microvolt:
+ description: |
+ Specifies the voltage range in microvolts chosen for the current full
+ scale range (FSR). The current is calculated by dividing the vsense
+ voltage by the value of the shunt resistor. The range should be set as
+ <minimum, maximum> by hardware design and it should not be changed
+ during runtime.
+
+ The VSENSE could be configured into the following full scale range:
+ - VSENSE has unipolar 0 mV to 100 mV FSR (default)
+ - VSENSE has bipolar -100 mV to 100 mV FSR
+ - VSENSE has bipolar -50 mV to 50 mV FSR
+ oneOf:
+ - items:
+ - const: 0
+ - const: 100000
+ - items:
+ - const: -100000
+ - const: 100000
+ - items:
+ - const: -50000
+ - const: 50000
+
+ microchip,accumulation-source:
+ $ref: /schemas/types.yaml#/definitions/string
+ description: |
+ The Hardware Accumulator may be used to accumulate VPOWER or VSENSE values
+ for any channel. By setting the accumulator for a channel to accumulate
+ the VPOWER values gives a measure of accumulated power over a time period,
+ which is equivalent to energy. Setting the accumulator for a channel to
+ accumulate VSENSE values gives a measure of accumulated current, which is
+ equivalent to charge.
+
+ The Hardware Accumulator could be configured as:
+ "energy" - Accumulator accumulates VPOWER (energy)
+ "charge" - Accumulator accumulates VSENSE (Coulomb Counter)
+ enum: [energy, charge]
+ default: energy
+
+required:
+ - compatible
+ - reg
+ - vdd-supply
+ - shunt-resistor-micro-ohms
+
+allOf:
+ - if:
+ properties:
+ compatible:
+ pattern: "^microchip,pac1[78]11$"
+ then:
+ properties:
+ microchip,vbus-input-range-microvolt:
+ oneOf:
+ - items:
+ - const: 0
+ - const: 42000000
+ - items:
+ - const: -42000000
+ - const: 42000000
+ - items:
+ - const: -21000000
+ - const: 21000000
+ default: [0, 42000000]
+ - if:
+ properties:
+ compatible:
+ pattern: "^microchip,pac1[78]21$"
+ then:
+ properties:
+ microchip,vbus-input-range-microvolt:
+ oneOf:
+ - items:
+ - const: 0
+ - const: 9000000
+ - items:
+ - const: -9000000
+ - const: 9000000
+ - items:
+ - const: -4500000
+ - const: 4500000
+ default: [0, 9000000]
+
+additionalProperties: false
+
+examples:
+ - |
+ i2c {
+ #address-cells = <1>;
+ #size-cells = <0>;
+
+ power-monitor@40 {
+ compatible = "microchip,pac1711";
+ reg = <0x40>;
+
+ shunt-resistor-micro-ohms = <11000000>;
+ label = "VDD3V3";
+ vdd-supply = <&vdd>;
+ microchip,vbus-input-range-microvolt = <(-21000000) 21000000>;
+ microchip,vsense-input-range-microvolt = <(-50000) 50000>;
+ microchip,accumulation-source = "energy";
+ };
+ };
+...
diff --git a/MAINTAINERS b/MAINTAINERS
index a92290fffa163f9fe8fe3f04bf66426f9a894409..399da37f79fd9768f29cc60aa5384a1ba9fe8afc 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -16337,6 +16337,12 @@ F: Documentation/devicetree/bindings/nvmem/microchip,sama7g5-otpc.yaml
F: drivers/nvmem/microchip-otpc.c
F: include/dt-bindings/nvmem/microchip,sama7g5-otpc.h
+MICROCHIP PAC1711 POWER/CURRENT MONITOR DRIVER
+M: Ariana Lazar <ariana.lazar@xxxxxxxxxxxxx>
+L: linux-iio@xxxxxxxxxxxxxxx
+S: Supported
+F: Documentation/devicetree/bindings/iio/adc/microchip,pac1711.yaml
+
MICROCHIP PAC1921 POWER/CURRENT MONITOR DRIVER
M: Matteo Martelli <matteomartelli3@xxxxxxxxx>
L: linux-iio@xxxxxxxxxxxxxxx
--
2.43.0