Re: [PATCH 1/2] dt-bindings: hwmon: Add Baikal-T1 PVT sensor bindings

[Sergey Semin]

On Thu, Mar 12, 2020 at 05:13:04PM -0500, Rob Herring wrote:
> On Fri, Mar 06, 2020 at 04:26:03PM +0300, Sergey.Semin@xxxxxxxxxxxxxxxxxxxx wrote:
> > From: Serge Semin <Sergey.Semin@xxxxxxxxxxxxxxxxxxxx>
> > 
> > Baikal-T1 SoC is equipped with an embedded process, voltage and
> > temperature sensor to monitor the chip internal environment like
> > temperature, supply voltage and transistors performance.
> > 
> > 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.
> > 
> > Signed-off-by: Maxim Kaurkin <maxim.kaurkin@xxxxxxxxxxxxxxxxxxxx>
> > Signed-off-by: Serge Semin <Sergey.Semin@xxxxxxxxxxxxxxxxxxxx>
> > Signed-off-by: Alexey Malahov <Alexey.Malahov@xxxxxxxxxxxxxxxxxxxx>
> > Cc: Thomas Bogendoerfer <tsbogend@xxxxxxxxxxxxxxxx>
> > Cc: Paul Burton <paulburton@xxxxxxxxxx>
> > Cc: Ralf Baechle <ralf@xxxxxxxxxxxxxx>
> > ---
> >  .../devicetree/bindings/hwmon/be,bt1-pvt.yaml | 100 ++++++++++++++++++
> >  1 file changed, 100 insertions(+)
> >  create mode 100644 Documentation/devicetree/bindings/hwmon/be,bt1-pvt.yaml
> > 
> > diff --git a/Documentation/devicetree/bindings/hwmon/be,bt1-pvt.yaml b/Documentation/devicetree/bindings/hwmon/be,bt1-pvt.yaml
> > new file mode 100644
> > index 000000000000..d575d124d538
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/hwmon/be,bt1-pvt.yaml
> > @@ -0,0 +1,100 @@
> > +# SPDX-License-Identifier: GPL-2.0
> 
> Dual license
> 

Ok. I'll add BSD-2-Clause here.

> > +#
> > +# Copyright (C) 2019 BAIKAL ELECTRONICS, JSC
> > +#
> > +# Baikal-T1 Process, Voltage, Temperature Sensor Device Tree Bindings.
> 
> drop
> 

Ok.

> > +#
> > +%YAML 1.2
> > +---
> > +$id: http://devicetree.org/schemas/hwmon/be,bt1-pvt.yaml#
> > +$schema: http://devicetree.org/meta-schemas/core.yaml#
> > +
> > +title: Baikal-T1 PVT Sensor Device Tree Bindings
> > +
> > +maintainers:
> > +  - Serge Semin <fancer.lancer@xxxxxxxxx>
> > +
> > +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: be,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
> > +
> > +additionalProperties: false
> > +
> > +required:
> > +  - compatible
> > +  - reg
> > +  - interrupts
> > +  - clocks
> > +  - clock-names
> > +
> > +examples:
> > +  - |
> > +    #include <dt-bindings/interrupt-controller/mips-gic.h>
> > +    #include <dt-bindings/clock/bt1-ccu.h>
> > +
> > +    pvt: pvt@1F200000 {
> 
> lowercase hex
> 

Ok. I'll also remove the bt1-ccu.h inclusion here, since that header
doesn't exist in the kernel source tree at the moment.

Regards,
-Sergey

> > +      compatible = "be,bt1-pvt";
> > +      reg = <0x1F200000 0x1000>;
> > +      #thermal-sensor-cells = <0>;
> > +
> > +      interrupts = <GIC_SHARED 31 IRQ_TYPE_LEVEL_HIGH>;
> > +
> > +      clocks = <&ccu_sys CCU_SYS_PVT_CLK>,
> > +               <&ccu_sys CCU_SYS_APB_CLK>;
> > +      clock-names = "ref", "pclk";
> > +    };
> > +...
> > -- 
> > 2.25.1
> >