baikal,bt1-pvt.yaml

  1# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
  2# Copyright (C) 2020 BAIKAL ELECTRONICS, JSC
  3%YAML 1.2
  4---
  5$id: http://devicetree.org/schemas/hwmon/baikal,bt1-pvt.yaml#
  6$schema: http://devicetree.org/meta-schemas/core.yaml#
  7
  8title: Baikal-T1 PVT Sensor
  9
 10maintainers:
 11  - Serge Semin <fancer.lancer@gmail.com>
 12
 13description: |
 14  Baikal-T1 SoC provides an embedded process, voltage and temperature
 15  sensor to monitor an internal SoC environment (chip temperature, supply
 16  voltage and process monitor) and on time detect critical situations,
 17  which may cause the system instability and even damages. The IP-block
 18  is based on the Analog Bits PVT sensor, but is equipped with a dedicated
 19  control wrapper, which provides a MMIO registers-based access to the
 20  sensor core functionality (APB3-bus based) and exposes an additional
 21  functions like thresholds/data ready interrupts, its status and masks,
 22  measurements timeout. Its internal structure is depicted on the next
 23  diagram:
 24
 25     Analog Bits core                     Bakal-T1 PVT control block
 26  +--------------------+                  +------------------------+
 27  | Temperature sensor |-+         +------| Sensors control        |
 28  |--------------------| |<---En---|      |------------------------|
 29  | Voltage sensor     |-|<--Mode--| +--->| Sampled data           |
 30  |--------------------| |<--Trim--+ |    |------------------------|
 31  | Low-Vt sensor      |-|           | +--| Thresholds comparator  |
 32  |--------------------| |---Data----| |  |------------------------|
 33  | High-Vt sensor     |-|           | +->| Interrupts status      |
 34  |--------------------| |--Valid--+-+ |  |------------------------|
 35  | Standard-Vt sensor |-+         +---+--| Interrupts mask        |
 36  +--------------------+                  |------------------------|
 37           ^                              | Interrupts timeout     |
 38           |                              +------------------------+
 39           |                                        ^  ^
 40  Rclk-----+----------------------------------------+  |
 41  APB3-------------------------------------------------+
 42
 43  This bindings describes the external Baikal-T1 PVT control interfaces
 44  like MMIO registers space, interrupt request number and clocks source.
 45  These are then used by the corresponding hwmon device driver to
 46  implement the sysfs files-based access to the sensors functionality.
 47
 48properties:
 49  compatible:
 50    const: baikal,bt1-pvt
 51
 52  reg:
 53    maxItems: 1
 54
 55  interrupts:
 56    maxItems: 1
 57
 58  clocks:
 59    items:
 60      - description: PVT reference clock
 61      - description: APB3 interface clock
 62
 63  clock-names:
 64    items:
 65      - const: ref
 66      - const: pclk
 67
 68  "#thermal-sensor-cells":
 69    description: Baikal-T1 can be referenced as the CPU thermal-sensor
 70    const: 0
 71
 72  baikal,pvt-temp-offset-millicelsius:
 73    description: |
 74      Temperature sensor trimming factor. It can be used to manually adjust the
 75      temperature measurements within 7.130 degrees Celsius.
 76    default: 0
 77    minimum: 0
 78    maximum: 7130
 79
 80additionalProperties: false
 81
 82required:
 83  - compatible
 84  - reg
 85  - interrupts
 86  - clocks
 87  - clock-names
 88
 89examples:
 90  - |
 91    #include <dt-bindings/interrupt-controller/mips-gic.h>
 92
 93    pvt@1f200000 {
 94      compatible = "baikal,bt1-pvt";
 95      reg = <0x1f200000 0x1000>;
 96      #thermal-sensor-cells = <0>;
 97
 98      interrupts = <GIC_SHARED 31 IRQ_TYPE_LEVEL_HIGH>;
 99
100      baikal,pvt-temp-offset-millicelsius = <1000>;
101
102      clocks = <&ccu_sys>, <&ccu_sys>;
103      clock-names = "ref", "pclk";
104    };
105...