linux/Documentation/devicetree/bindings/hwmon/baikal,bt1-pvt.yaml

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YAML

# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
# Copyright (C) 2020 BAIKAL ELECTRONICS, JSC
%YAML 1.2
---
$id: http://devicetree.org/schemas/hwmon/baikal,bt1-pvt.yaml#
$schema: http://devicetree.org/meta-schemas/core.yaml#
title: Baikal-T1 PVT Sensor
maintainers:
- Serge Semin <fancer.lancer@gmail.com>
description: |
Baikal-T1 SoC provides an embedded process, voltage and temperature
sensor to monitor an internal SoC environment (chip temperature, supply
voltage and process monitor) and on time detect critical situations,
which may cause the system instability and even damages. The IP-block
is based on the Analog Bits PVT sensor, but is equipped with a dedicated
control wrapper, which provides a MMIO registers-based access to the
sensor core functionality (APB3-bus based) and exposes an additional
functions like thresholds/data ready interrupts, its status and masks,
measurements timeout. Its internal structure is depicted on the next
diagram:
Analog Bits core Bakal-T1 PVT control block
+--------------------+ +------------------------+
| Temperature sensor |-+ +------| Sensors control |
|--------------------| |<---En---| |------------------------|
| Voltage sensor |-|<--Mode--| +--->| Sampled data |
|--------------------| |<--Trim--+ | |------------------------|
| Low-Vt sensor |-| | +--| Thresholds comparator |
|--------------------| |---Data----| | |------------------------|
| High-Vt sensor |-| | +->| Interrupts status |
|--------------------| |--Valid--+-+ | |------------------------|
| Standard-Vt sensor |-+ +---+--| Interrupts mask |
+--------------------+ |------------------------|
^ | Interrupts timeout |
| +------------------------+
| ^ ^
Rclk-----+----------------------------------------+ |
APB3-------------------------------------------------+
This bindings describes the external Baikal-T1 PVT control interfaces
like MMIO registers space, interrupt request number and clocks source.
These are then used by the corresponding hwmon device driver to
implement the sysfs files-based access to the sensors functionality.
properties:
compatible:
const: baikal,bt1-pvt
reg:
maxItems: 1
interrupts:
maxItems: 1
clocks:
items:
- description: PVT reference clock
- description: APB3 interface clock
clock-names:
items:
- const: ref
- const: pclk
"#thermal-sensor-cells":
description: Baikal-T1 can be referenced as the CPU thermal-sensor
const: 0
baikal,pvt-temp-offset-millicelsius:
description: |
Temperature sensor trimming factor. It can be used to manually adjust the
temperature measurements within 7.130 degrees Celsius.
maxItems: 1
items:
default: 0
minimum: 0
maximum: 7130
unevaluatedProperties: false
required:
- compatible
- reg
- interrupts
- clocks
- clock-names
examples:
- |
#include <dt-bindings/interrupt-controller/mips-gic.h>
pvt@1f200000 {
compatible = "baikal,bt1-pvt";
reg = <0x1f200000 0x1000>;
#thermal-sensor-cells = <0>;
interrupts = <GIC_SHARED 31 IRQ_TYPE_LEVEL_HIGH>;
baikal,pvt-temp-trim-millicelsius = <1000>;
clocks = <&ccu_sys>, <&ccu_sys>;
clock-names = "ref", "pclk";
};
...