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

From: Billy Tsai
Date: Wed Jul 14 2021 - 00:03:02 EST


On 2021/7/14, 6:14 AM, "Rob Herring" <robh@xxxxxxxxxx> 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@xxxxxxxxxxxxxx>
>> ---
>> .../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@xxxxxxxxxxxxxx>
>> +
>> +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@xxxxxxxxxxxxxx>
>> +
>> +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]+)?$":
>> + $ref: ../pwm/aspeed,ast2600-pwm.yaml
>> +
>> + "^tach(@[0-9a-f]+)?$":
>> + $ref: ../hwmon/aspeed,ast2600-tach.yaml
>> +
>> +additionalProperties: false
>> +
>> +examples:
>> + - |
>> + #include <dt-bindings/clock/ast2600-clock.h>
>> + pwm_tach: pwm_tach@1e610000 {
>> + compatible = "aspeed,ast2600-pwm-tach", "syscon", "simple-mfd";
>> + reg = <0x1e610000 0x100>;
>> + clocks = <&syscon ASPEED_CLK_AHB>;
>> + resets = <&syscon ASPEED_RESET_PWM>;
>> +
>> + pwm: pwm {
>> + compatible = "aspeed,ast2600-pwm";
>> + #address-cells = <1>;
>> + #size-cells = <0>;
>> + #pwm-cells = <3>;
>> + pinctrl-names = "default";
>> + pinctrl-0 = <&pinctrl_pwm0_default>;
>> + pwm-ch@0 {
>> + reg = <0>;
>> + aspeed,wdt-reload-enable;
>> + aspeed,wdt-reload-duty-point = <32>;
>> + };
>> + };
>> +
>> + tach: tach {
>> + compatible = "aspeed,ast2600-tach";
>> + #address-cells = <1>;
>> + #size-cells = <0>;
>> + pinctrl-names = "default";
>> + pinctrl-0 = <&pinctrl_tach0_default>;
>> + tach-ch@0 {
>> + reg = <0>;
>> + aspeed,min-rpm = <1000>;
>> + aspeed,pulse-pr = <2>;
>> + aspeed,tach-div = <5>;
>> + };
>> + };
>> + };
>> diff --git a/Documentation/devicetree/bindings/pwm/aspeed,ast2600-pwm.yaml b/Documentation/devicetree/bindings/pwm/aspeed,ast2600-pwm.yaml
>> new file mode 100644
>> index 000000000000..f501f8a769df
>> --- /dev/null
>> +++ b/Documentation/devicetree/bindings/pwm/aspeed,ast2600-pwm.yaml
>> @@ -0,0 +1,64 @@
>> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
>> +# Copyright (C) 2021 Aspeed, Inc.
>> +%YAML 1.2
>> +---
>> +$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@xxxxxxxxxxxxxx>
>> +
>> +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
>>
>>