On Mon, Nov 13, 2023 at 8:11 PM Billy Tsai <billy_tsai@xxxxxxxxxxxxxx> wrote: > > > > Document the compatible for aspeed,ast2600-pwm-tach device, which can > > > support up to 16 PWM outputs and 16 fan tach input. > > > > > > Signed-off-by: Billy Tsai <billy_tsai@xxxxxxxxxxxxxx> > > > --- > > > .../bindings/hwmon/aspeed,g6-pwm-tach.yaml | 69 +++++++++++++++++++ > > > 1 file changed, 69 insertions(+) > > > create mode 100644 Documentation/devicetree/bindings/hwmon/aspeed,g6-pwm-tach.yaml > > > > > > diff --git a/Documentation/devicetree/bindings/hwmon/aspeed,g6-pwm-tach.yaml b/Documentation/devicetree/bindings/hwmon/aspeed,g6-pwm-tach.yaml > > > new file mode 100644 > > > index 000000000000..c615fb10705c > > > --- /dev/null > > > +++ b/Documentation/devicetree/bindings/hwmon/aspeed,g6-pwm-tach.yaml > > > @@ -0,0 +1,69 @@ > > > +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) > > > +# Copyright (C) 2023 Aspeed, Inc. > > > +%YAML 1.2 > > > +--- > > > +$id: http://devicetree.org/schemas/hwmon/aspeed,g6-pwm-tach.yaml# > > > +$schema: http://devicetree.org/meta-schemas/core.yaml# > > > + > > > +title: ASPEED G6 PWM and Fan Tach controller > > > + > > > +maintainers: > > > + - Billy Tsai <billy_tsai@xxxxxxxxxxxxxx> > > > + > > > +description: | > > > + The ASPEED PWM controller can support up to 16 PWM outputs. > > > + The ASPEED Fan Tacho controller can support up to 16 fan tach input. > > > + They are independent hardware blocks, which are different from the > > > + previous version of the ASPEED chip. > > > + > > > +properties: > > > + compatible: > > > + enum: > > > + - aspeed,ast2600-pwm-tach > > > + > > > + reg: > > > + maxItems: 1 > > > + > > > + clocks: > > > + maxItems: 1 > > > + > > > + resets: > > > + maxItems: 1 > > > + > > > + "#pwm-cells": > > > + const: 3 > > > + > > > +patternProperties: > > > + "^fan-[0-9]+$": > > > + $ref: fan-common.yaml# > > > + unevaluatedProperties: false > > > + required: > > > + - tach-ch > > > + > > > +required: > > > + - reg > > > + - clocks > > > + - resets > > > + - "#pwm-cells" > > > + - compatible > > > + > > > +additionalProperties: false > > > + > > > +examples: > > > + - | > > > + #include <dt-bindings/clock/aspeed-clock.h> > > > + pwm_tach: pwm-tach-controller@1e610000 { > > > + compatible = "aspeed,ast2600-pwm-tach"; > > > + reg = <0x1e610000 0x100>; > > > + clocks = <&syscon ASPEED_CLK_AHB>; > > > + resets = <&syscon ASPEED_RESET_PWM>; > > > + #pwm-cells = <3>; > > > + > > > + fan-0 { > > > I assume there's a PWM connection here? How do you know which PWM? You > > said the tach channel is independent, so it is not that. > > > It should not be 0 from 'fan-0' because that's just a meaningless index. > > > You either need 'pwms' here or you can use 'reg' and the reg value is > > the PWM channel. > > Hi Rob, this binding is used to export the PWM provider and the Fan monitor (i.e., Tach). > If the user wants to add the PWM connection for the fan, it can be done as follows: > > fan0: pwm-fan0 { > compatible = "pwm-fan"; > pwms = <&pwm_tach 0 40000 0>; > cooling-min-state = <0>; > cooling-max-state = <3>; > #cooling-cells = <2>; > cooling-levels = <0 15 128 255>; > }; > > This will reuse the existing PWM fan driver (e.g., pwm-fan.c). I'm confused now. So what are the child nodes you have? You are defining the fan in 2 places? The "pwm-fan" driver supports a tach via an interrupt, so how would this work in your case? Rob
