[v9 1/2] dt-bindings: Add bindings for aspeed pwm-tach.

Billy Tsai billy_tsai at aspeedtech.com
Wed Jul 14 14:02:34 AEST 2021


On 2021/7/14, 6:14 AM, "Rob Herring" <robh at kernel.org> wrote:

    On Fri, Jul 09, 2021 at 02:52:16PM +0800, Billy Tsai wrote:
    >> This patch adds device binding for aspeed pwm-tach device which is a
    >> multi-function device include pwm and tach function and pwm/tach device
    >> bindings which should be the child-node of pwm-tach device.

    >I'll say it again, the fan control h/w needs some common bindings for 
    >describing fans and fan connections to pwm and tach. I'm not going to 
    >sign off on more fan bindings just doing their own thing.

This patch doesn't use to binding the fan control h/w. It is used to binding the two independent h/w blocks.
One is used to provide pwm output and another is used to monitor the speed of the input.
It is different from "aspeed-pwm-tacho.txt" and "npcm750-pwm-fan.txt" which only focus on fan usage.
It is more like the "kontron,sl28cpld.yaml" the device includes a fan monitor and PWM output devices.

    >> 
    >> Signed-off-by: Billy Tsai <billy_tsai at aspeedtech.com>
    >> ---
    >>  .../bindings/hwmon/aspeed,ast2600-tach.yaml   | 69 +++++++++++++++
    >>  .../bindings/mfd/aspeed,ast2600-pwm-tach.yaml | 87 +++++++++++++++++++
    >>  .../bindings/pwm/aspeed,ast2600-pwm.yaml      | 64 ++++++++++++++
    >>  3 files changed, 220 insertions(+)
    >>  create mode 100644 Documentation/devicetree/bindings/hwmon/aspeed,ast2600-tach.yaml
    >>  create mode 100644 Documentation/devicetree/bindings/mfd/aspeed,ast2600-pwm-tach.yaml
    >>  create mode 100644 Documentation/devicetree/bindings/pwm/aspeed,ast2600-pwm.yaml
    >> 
    >> diff --git a/Documentation/devicetree/bindings/hwmon/aspeed,ast2600-tach.yaml b/Documentation/devicetree/bindings/hwmon/aspeed,ast2600-tach.yaml
    >> new file mode 100644
    >> index 000000000000..a08471f96a61
    >> --- /dev/null
    >> +++ b/Documentation/devicetree/bindings/hwmon/aspeed,ast2600-tach.yaml
    >> @@ -0,0 +1,69 @@
    >> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
    >> +# Copyright (C) 2021 Aspeed, Inc.
    >> +%YAML 1.2
    >> +---
    >> +$id: http://devicetree.org/schemas/hwmon/aspeed,ast2600-tach.yaml#
    >> +$schema: http://devicetree.org/meta-schemas/core.yaml#
    >> +
    >> +title: Aspeed Ast2600 Tach controller
    >> +
    >> +maintainers:
    >> +  - Billy Tsai <billy_tsai at aspeedtech.com>
    >> +
    >> +description: |
    >> +  The Aspeed Tach controller can support upto 16 fan input.
    >> +  This module is part of the ast2600-pwm-tach multi-function device. For more
    >> +  details see ../mfd/aspeed,ast2600-pwm-tach.yaml.
    >> +
    >> +properties:
    >> +  compatible:
    >> +    enum:
    >> +      - aspeed,ast2600-tach
    >> +
    >> +  "#address-cells":
    >> +    const: 1
    >> +
    >> +  "#size-cells":
    >> +    const: 0
    >> +
    >> +  pinctrl-0: true
    >> +
    >> +  pinctrl-names:
    >> +    const: default
    >> +
    >> +required:
    >> +  - compatible
    >> +  - "#address-cells"
    >> +  - "#size-cells"
    >> +
    >> +additionalProperties:
    >> +  type: object
    >> +  properties:
    >> +    reg:
    >> +      description:
    >> +        The tach channel used for this fan.
    >> +      maxItems: 1
    >> +
    >> +    aspeed,min-rpm:
    >> +      description:
    >> +        define the minimal revolutions per minute of the measure fan
    >> +        used to calculate the sample period of tach
    >> +      default: 1000
    >> +
    >> +    aspeed,pulse-pr:
    >> +      description:
    >> +        Value specifying the number of pulses per revolution of the
    >> +        monitored FAN.
    >> +      default: 2
    >> +
    >> +    aspeed,tach-div:
    >> +      description:
    >> +        define the tachometer clock divider as an integer. Formula of
    >> +        tach clock = clock source / (2^tach-div)^2
    >> +      minimum: 0
    >> +      maximum: 15
    >> +      # The value that should be used if the property is not present
    >> +      default: 5
    >> +
    >> +  required:
    >> +    - reg
    >> diff --git a/Documentation/devicetree/bindings/mfd/aspeed,ast2600-pwm-tach.yaml b/Documentation/devicetree/bindings/mfd/aspeed,ast2600-pwm-tach.yaml
    >> new file mode 100644
    >> index 000000000000..ab49aff1928a
    >> --- /dev/null
    >> +++ b/Documentation/devicetree/bindings/mfd/aspeed,ast2600-pwm-tach.yaml
    >> @@ -0,0 +1,87 @@
    >> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
    >> +# Copyright (C) 2021 Aspeed, Inc.
    >> +%YAML 1.2
    >> +---
    >> +$id: http://devicetree.org/schemas/mfd/aspeed,ast2600-pwm-tach.yaml#
    >> +$schema: http://devicetree.org/meta-schemas/core.yaml#
    >> +
    >> +title: PWM Tach controller Device Tree Bindings
    >> +
    >> +description: |
    >> +  The PWM Tach controller is represented as a multi-function device which
    >> +  includes:
    >> +    PWM
    >> +    Tach
    >> +
    >> +maintainers:
    >> +  - Billy Tsai <billy_tsai at aspeedtech.com>
    >> +
    >> +properties:
    >> +  compatible:
    >> +    items:
    >> +      - enum:
    >> +          - aspeed,ast2600-pwm-tach
    >> +      - const: syscon
    >> +      - const: simple-mfd
    >> +
    >> +  reg:
    >> +    maxItems: 1
    >> +
    >> +  clocks:
    >> +    maxItems: 1
    >> +
    >> +  resets:
    >> +    maxItems: 1
    >> +
    >> +required:
    >> +  - compatible
    >> +  - reg
    >> +  - clocks
    >> +  - resets
    >> +
    >> +patternProperties:
    >> +  "^pwm(@[0-9a-f]+)?$":
    >> +    $ref: ../pwm/aspeed,ast2600-pwm.yaml
    >> +
    >> +  "^tach(@[0-9a-f]+)?$":
    >> +    $ref: ../hwmon/aspeed,ast2600-tach.yaml
    >> +
    >> +additionalProperties: false
    >> +
    >> +examples:
    >> +  - |
    >> +    #include <dt-bindings/clock/ast2600-clock.h>
    >> +    pwm_tach: pwm_tach at 1e610000 {
    >> +      compatible = "aspeed,ast2600-pwm-tach", "syscon", "simple-mfd";
    >> +      reg = <0x1e610000 0x100>;
    >> +      clocks = <&syscon ASPEED_CLK_AHB>;
    >> +      resets = <&syscon ASPEED_RESET_PWM>;
    >> +
    >> +      pwm: pwm {
    >> +        compatible = "aspeed,ast2600-pwm";
    >> +        #address-cells = <1>;
    >> +        #size-cells = <0>;
    >> +        #pwm-cells = <3>;
    >> +        pinctrl-names = "default";
    >> +        pinctrl-0 = <&pinctrl_pwm0_default>;
    >> +        pwm-ch at 0 {
    >> +          reg = <0>;
    >> +          aspeed,wdt-reload-enable;
    >> +          aspeed,wdt-reload-duty-point = <32>;
    >> +        };
    >> +      };
    >> +
    >> +      tach: tach {
    >> +        compatible = "aspeed,ast2600-tach";
    >> +        #address-cells = <1>;
    >> +        #size-cells = <0>;
    >> +        pinctrl-names = "default";
    >> +        pinctrl-0 = <&pinctrl_tach0_default>;
    >> +        tach-ch at 0 {
    >> +          reg = <0>;
    >> +          aspeed,min-rpm = <1000>;
    >> +          aspeed,pulse-pr = <2>;
    >> +          aspeed,tach-div = <5>;
    >> +        };
    >> +      };
    >> +    };
    >> diff --git a/Documentation/devicetree/bindings/pwm/aspeed,ast2600-pwm.yaml b/Documentation/devicetree/bindings/pwm/aspeed,ast2600-pwm.yaml
    >> new file mode 100644
    >> index 000000000000..f501f8a769df
    >> --- /dev/null
    >> +++ b/Documentation/devicetree/bindings/pwm/aspeed,ast2600-pwm.yaml
    >> @@ -0,0 +1,64 @@
    >> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
    >> +# Copyright (C) 2021 Aspeed, Inc.
    >> +%YAML 1.2
    >> +---
    >> +$id: http://devicetree.org/schemas/pwm/aspeed,ast2600-pwm.yaml#
    >> +$schema: http://devicetree.org/meta-schemas/core.yaml#
    >> +
    >> +title: Aspeed Ast2600 PWM controller
    >> +
    >> +maintainers:
    >> +  - Billy Tsai <billy_tsai at aspeedtech.com>
    >> +
    >> +description: |
    >> +  The Aspeed PWM controller can support upto 16 PWM outputs.
    >> +  This module is part of the ast2600-pwm-tach multi-function device. For more
    >> +  details see ../mfd/aspeed,ast2600-pwm-tach.yaml.
    >> +
    >> +properties:
    >> +  compatible:
    >> +    enum:
    >> +      - aspeed,ast2600-pwm
    >> +
    >> +  "#pwm-cells":
    >> +    const: 3
    >> +
    >> +  "#address-cells":
    >> +    const: 1
    >> +
    >> +  "#size-cells":
    >> +    const: 0
    >> +
    >> +  pinctrl-0: true
    >> +
    >> +  pinctrl-names:
    >> +    const: default
    >> +
    >> +required:
    >> +  - compatible
    >> +  - "#pwm-cells"
    >> +  - "#address-cells"
    >> +  - "#size-cells"
    >> +
    >> +additionalProperties:
    >> +  description: Set extend properties for each pwm channel.
    >> +  type: object
    >> +  properties:
    >> +    reg:
    >> +      description:
    >> +        The pwm channel index.
    >> +      maxItems: 1
    >> +
    >> +    aspeed,wdt-reload-enable:
    >> +      type: boolean
    >> +      description:
    >> +        Enable the function of wdt reset reload duty point.
    >> +
    >> +    aspeed,wdt-reload-duty-point:
    >> +      description:
    >> +        Define the duty point after wdt reset, 0 = 100%
    >> +      minimum: 0
    >> +      maximum: 255
    >> +
    >> +  required:
    >> +    - reg
    >> -- 
    >> 2.25.1
    >> 
    >>



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