On Sat, 1 May 2021 18:25:18 +0000 Jozsef Horvath <info@xxxxxxxxxxx> wrote: > This is a device tree schema for iio driver for > Texas Instruments ADS7142 dual-channel, programmable sensor monitor. > > Datasheet: https://www.ti.com/lit/ds/symlink/ads7142.pdf > > Signed-off-by: Jozsef Horvath <info@xxxxxxxxxxx> > --- > --- > .../bindings/iio/adc/ti,ads7142.yaml | 198 ++++++++++++++++++ > 1 file changed, 198 insertions(+) > create mode 100644 Documentation/devicetree/bindings/iio/adc/ti,ads7142.yaml > > diff --git a/Documentation/devicetree/bindings/iio/adc/ti,ads7142.yaml b/Documentation/devicetree/bindings/iio/adc/ti,ads7142.yaml > new file mode 100644 > index 000000000000..b4e752160156 > --- /dev/null > +++ b/Documentation/devicetree/bindings/iio/adc/ti,ads7142.yaml > @@ -0,0 +1,198 @@ > +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) > +%YAML 1.2 > +--- > +$id: "http://devicetree.org/schemas/iio/adc/ti,ads7142.yaml#"; > +$schema: "http://devicetree.org/meta-schemas/core.yaml#"; > + > +title: Texas Instruments ADS7142 adc driver device tree bindings > + > +maintainers: > + - József Horváth <info@xxxxxxxxxxx> > + > +description: | > + This document is for describing the required device tree parameters > + for ads7142 adc driver. Document describes hardware, not a particular driver. So just refer to the device here. There may well be other drives in future using the same binding (e.g. in an RTOS). > + The required parameters for proper operation are described below. > + > + Datasheet: https://www.ti.com/lit/ds/symlink/ads7142.pdf > + > + Operation modes supportedby the driver: > + When the 'ti,monitoring-mode' property is not present > + in the devicetree node definition, the driver initiates a single > + conversion in the device for each read request > + (/sys/bus/iio/devices/iio:deviceX/in_voltageY_raw). > + This is a one-shot conversion, and it is called > + "Manual Mode" in the datasheet. > + > + When the 'ti,monitoring-mode' property is present > + in the devicetree node definition, the driver configures > + the device's digital window comparator and sets the device's > + data buffer operation mode to pre alert data mode. > + The driver reads the conversion result when the BUSY/RDY interrupt > + fires, and keeps the value until the next BUSY/RDY interrupt > + or the first read request > + (/sys/bus/iio/devices/iio:deviceX/in_voltageY_raw). > + The digital window comparator and hysteresis parameters > + can be controlled by: > + - the devicetree definition of channel node > + - iio sysfs interfaces > + This is event driven conversion, and is called > + "Autonomous Mode with Pre Alert Data" in the datasheet. > + This mode can be used to wake up the system with the ALERT pin, > + in case when the monitored voltage level is out of the configured range. I talked about these in the driver review so look there for comments. Short summary is this is something userspace should have control off (assuming irq is wired up) not dt. > + > +properties: > + compatible: > + const: ti,ads7142 > + > + reg: > + maxItems: 1 > + > + interrupts: > + description: | > + The BUSY/PDY pin is used as interrupt line in autonomous monitoring mode. > + maxItems: 1 > + > + vref-supply: > + description: Regulator for the reference voltage > + > + power-supply: true These don't match the naming on the pin diagram. > + > + "#address-cells": > + const: 1 > + > + "#size-cells": > + const: 0 > + > + "#io-channel-cells": > + const: 1 > + > + ti,osc-sel: > + description: | > + If present, the driver selects the high speed oscillator. > + See chapter 7.3.5 Oscillator and Timing Control in datasheet. > + type: boolean This looks connected to the possible sampling frequencies when in various autonomous modes. Should it be controlled by userspace? > + > + ti,n-clk: > + description: | > + nCLK is number of clocks in one conversion cycle. > + See chapter 7.3.5 Oscillator and Timing Control in datasheet. Sounds like a policy decision for userspace. > + $ref: /schemas/types.yaml#/definitions/uint32 > + maximum: 255 > + minimum: 0 > + > + ti,monitoring-mode: > + description: | > + If present, the driver selects the autonomous monitoring mode with pre alert data. > + See chapter 7.4 Device Functional Modes in datasheet. As mentioned in the driver review, this looks like something we should control from userspace not dt to me. > + type: boolean > + > +patternProperties: > + "^channel@[0-1]$": > + $ref: "adc.yaml" > + type: object > + description: | > + Represents the external channels which are connected to the ADC. > + properties: > + reg: > + description: | > + The channel number. > + items: > + minimum: 0 > + maximum: 1 > + "ti,threshold-falling": > + description: The low threshold for channel For these, we need a strong argument presented in this doc for why they are not a question of policy (and hence why they should be in dt at all). > + $ref: /schemas/types.yaml#/definitions/uint32 > + maximum: 4095 > + minimum: 0 > + "ti,threshold-rising": > + description: The high threshold for channel > + $ref: /schemas/types.yaml#/definitions/uint32 > + maximum: 4095 > + minimum: 0 > + "ti,hysteresis": > + description: The hysteresis for both comparators for channel > + $ref: /schemas/types.yaml#/definitions/uint32 > + maximum: 63 > + minimum: 0 > + > + required: > + - reg > + > + additionalProperties: false > + > +allOf: > + - if: > + required: > + - ti,monitoring-mode > + then: > + required: > + - interrupts > + > +required: > + - compatible > + - "#io-channel-cells" > + > +additionalProperties: false > + > +examples: > + - | > + i2c { > + #address-cells = <1>; > + #size-cells = <0>; > + adc@18 { I would not bother having two examples. The second one covers more things afterall and the binding makes it clear what is required. > + compatible = "ti,ads7142"; > + reg = <0x18>; > + #address-cells = <1>; > + #size-cells = <0>; > + #io-channel-cells = <1>; > + > + vref-supply = <&vdd_3v3_reg>; > + power-supply = <&vdd_1v8_reg>; > + > + channel@0 { > + reg = <0>; > + }; > + > + channel@1 { > + reg = <1>; > + }; > + }; > + }; > + - | > + i2c { > + #address-cells = <1>; > + #size-cells = <0>; > + adc@1f { > + compatible = "ti,ads7142"; > + reg = <0x1f>; > + #address-cells = <1>; > + #size-cells = <0>; > + > + #io-channel-cells = <1>; > + > + vref-supply = <&vdd_3v3_reg>; > + power-supply = <&vdd_1v8_reg>; > + > + interrupt-parent = <&gpio>; > + interrupts = <7 2>; > + > + ti,monitoring-mode; > + > + channel@0 { > + reg = <0>; > + ti,threshold-falling = <1000>; > + ti,threshold-rising = <2000>; > + ti,hysteresis = <20>; > + }; > + > + channel@1 { > + reg = <1>; > + ti,threshold-falling = <100>; > + ti,threshold-rising = <2500>; > + ti,hysteresis = <0>; > + }; > + }; > + }; > +... > +
