On Thu, Feb 13, 2025 at 11:08:59AM +0100, Philipp Zabel wrote: > On Do, 2025-02-13 at 10:08 +0800, Inochi Amaoto wrote: > > Some SoCs from Aspeed, Allwinner, Sophgo and Synopsys have > > a simple reset controller by toggling bit. It is a hard time > > for each device to add its own compatible to the driver. > > Since this device share a common design, it is possible to > > add a common device to reduce these unnecessary change. > > > > Add common binding for these kind generic reset controller. > > > > Signed-off-by: Inochi Amaoto <inochiama@xxxxxxxxx> > > --- > > .../bindings/reset/reset-simple.yaml | 42 +++++++++++++++++++ > > 1 file changed, 42 insertions(+) > > create mode 100644 Documentation/devicetree/bindings/reset/reset-simple.yaml > > > > diff --git a/Documentation/devicetree/bindings/reset/reset-simple.yaml b/Documentation/devicetree/bindings/reset/reset-simple.yaml > > new file mode 100644 > > index 000000000000..77584e23e8e8 > > --- /dev/null > > +++ b/Documentation/devicetree/bindings/reset/reset-simple.yaml > > @@ -0,0 +1,42 @@ > > +# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause) > > +%YAML 1.2 > > +--- > > +$id: http://devicetree.org/schemas/reset/reset-simple.yaml# > > +$schema: http://devicetree.org/meta-schemas/core.yaml# > > + > > +title: Generic BIT Reset Controller > > + > > +maintainers: > > + - Inochi Amaoto <inochiama@xxxxxxxxx> > > + > > +description: > > + Some reset controller devices uses a simple method to perform > > + assert/deassert by toggling bit. Some SoCs from Aspeed, Allwinner, > > + Sophgo and Synopsys have this kind of reset controller instances. > > I think some properties should be documented that make reset > controllers "simple" according to this binding. > > For example, right now, the reset-simple driver assumes the following: > > - There is a single, contiguous range of 32-bit registers. > - All bits in each register directly control a reset line. > - There are no self-deasserting resets. > - There are no timing requirements. > - The bits are exclusively resets, nothing else. > - All bits behave the same, so all reset bits are either > active-high or all are active-low. > - The bits can be read back, but the read status may > be active-low independently from the writes. > Thanks, I will add these assumes in to the binding. > > +properties: > > + compatible: > > + enum: > > + - reset-simple-high > > + - reset-simple-low > > I wonder if it would be better to have a single > > compatible: > const: reset-simple > > and a boolean property, e.g. > > active-low: > type: boolean > > like in leds/common.yaml. Also it should be documented clearly what > this means for reads and writes. > Yeah, it is better to have a property instead of defining a base compatible. With this property, there are two ways to process this property with existing device: 1. If device has defined the data, the active-low is ignored 2. If device has defined the data, the active-low will overwrite the device data. I wonder which one is better? > > + reg: > > + maxItems: 1 > > + > > + "#reset-cells": > > + const: 1 > > + > > +required: > > + - compatible > > + - reg > > + - "#reset-cells" > > + > > +additionalProperties: false > > + > > +examples: > > + - | > > + reset-controller@1000000 { > > + compatible = "reset-simple-high"; > > The example should probably include a SoC specific compatible? > > regards > Philipp I think it is OK. But I think it should be added when a specific compatible is coming. Regards, Inochi
