On Tue, Oct 5, 2021 at 10:59 AM Hector Martin <marcan@xxxxxxxxx> wrote: > > This syscon child node represents a single SoC device controlled by the > PMGR block. This layout allows us to declare all device power state > controls (power/clock gating and reset) in the device tree, including > dependencies, instead of hardcoding it into the driver. The register > layout is uniform. > > Each pmgr-pwrstate node provides genpd and reset features, to be > consumed by downstream device nodes. > > Future SoCs are expected to use backwards compatible registers, and the > "apple,pmgr-pwrstate" represents any such interfaces (possibly with > additional features gated by the more specific compatible), allowing > them to be bound without driver updates. If a backwards incompatible > change is introduced in future SoCs, it will require a new compatible, > such as "apple,pmgr-pwrstate-v2". Is that because past SoCs used the same registers? I don't see how else you have any insight to what future SoCs will do. Normally we don't do 1 node per register type bindings, so I'm a bit leery about doing 1 node per domain. > > Signed-off-by: Hector Martin <marcan@xxxxxxxxx> > --- > .../bindings/power/apple,pmgr-pwrstate.yaml | 117 ++++++++++++++++++ > MAINTAINERS | 1 + > 2 files changed, 118 insertions(+) > create mode 100644 Documentation/devicetree/bindings/power/apple,pmgr-pwrstate.yaml > > diff --git a/Documentation/devicetree/bindings/power/apple,pmgr-pwrstate.yaml b/Documentation/devicetree/bindings/power/apple,pmgr-pwrstate.yaml > new file mode 100644 > index 000000000000..a14bf5f30ff0 > --- /dev/null > +++ b/Documentation/devicetree/bindings/power/apple,pmgr-pwrstate.yaml > @@ -0,0 +1,117 @@ > +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) > +%YAML 1.2 > +--- > +$id: http://devicetree.org/schemas/power/apple,pmgr-pwrstate.yaml# > +$schema: http://devicetree.org/meta-schemas/core.yaml# > + > +title: Apple SoC PMGR Power States > + > +maintainers: > + - Hector Martin <marcan@xxxxxxxxx> > + > +allOf: > + - $ref: "power-domain.yaml#" > + > +description: | > + Apple SoCs include a PMGR block responsible for power management, > + which can control various clocks, resets, power states, and > + performance features. This binding describes the device power > + state registers, which control power states and resets. > + > + Each instance of a power controller within the PMGR syscon node > + represents a generic power domain provider, as documented in > + Documentation/devicetree/bindings/power/power-domain.yaml. > + The provider controls a single SoC block. The power hierarchy is > + represented via power-domains relationships between these nodes. > + > + See Documentation/devicetree/bindings/arm/apple/apple,pmgr.yaml > + for the top-level PMGR node documentation. > + > + IP cores belonging to a power domain should contain a > + "power-domains" property that is a phandle for the > + power domain node representing the domain. > + > +properties: > + $nodename: > + pattern: "^power-controller@[0-9a-f]+$" Drop this and define this node in the syscon schema with a $ref to this schema. > + > + compatible: > + items: > + - enum: > + - apple,t8103-pmgr-pwrstate > + - const: apple,pmgr-pwrstate > + > + reg: > + maxItems: 1 > + > + "#power-domain-cells": > + const: 0 > + > + "#reset-cells": > + const: 0 > + > + power-domains: > + description: > + Reference to parent power domains. A domain may have multiple parents, > + and all will be powered up when it is powered. > + > + apple,domain-name: > + description: | > + Specifies the name of the SoC device being controlled. This is used to > + name the power/reset domains. > + $ref: /schemas/types.yaml#/definitions/string No other power domain binding needs this, why do you? > + > + apple,always-on: > + description: | > + Forces this power domain to always be powered up. > + type: boolean > + > +required: > + - compatible > + - reg > + - "#power-domain-cells" > + - "#reset-cells" > + - "apple,domain-name" > + > +additionalProperties: false > + > +examples: I prefer 1 complete example in the MFD schema rather than piecemeal examples. > + - | > + soc { > + #address-cells = <2>; > + #size-cells = <2>; > + > + power-management@23b700000 { > + compatible = "apple,t8103-pmgr", "apple,pmgr", "syscon", "simple-mfd"; > + #address-cells = <1>; > + #size-cells = <0>; As the child nodes are memory mapped devices, size should be 1. Then address translation works (though Linux doesn't care (currently)). > + reg = <0x2 0x3b700000 0x0 0x14000>; > + > + ps_sio: power-controller@1c0 { > + compatible = "apple,t8103-pmgr-pwrstate", "apple,pmgr-pwrstate"; > + reg = <0x1c0>; > + #power-domain-cells = <0>; > + #reset-cells = <0>; > + apple,domain-name = "sio"; > + apple,always-on; > + }; > + > + ps_uart_p: power-controller@220 { > + compatible = "apple,t8103-pmgr-pwrstate", "apple,pmgr-pwrstate"; > + reg = <0x220>; > + #power-domain-cells = <0>; > + #reset-cells = <0>; > + apple,domain-name = "uart_p"; > + power-domains = <&ps_sio>; > + }; > + > + ps_uart0: power-controller@270 { > + compatible = "apple,t8103-pmgr-pwrstate", "apple,pmgr-pwrstate"; > + reg = <0x270>; > + #power-domain-cells = <0>; > + #reset-cells = <0>; > + apple,domain-name = "uart0"; > + power-domains = <&ps_uart_p>; > + }; > + }; > + }; > diff --git a/MAINTAINERS b/MAINTAINERS > index d25598842d15..5fe53d9a2956 100644 > --- a/MAINTAINERS > +++ b/MAINTAINERS > @@ -1722,6 +1722,7 @@ F: Documentation/devicetree/bindings/arm/apple.yaml > F: Documentation/devicetree/bindings/arm/apple/* > F: Documentation/devicetree/bindings/interrupt-controller/apple,aic.yaml > F: Documentation/devicetree/bindings/pinctrl/apple,pinctrl.yaml > +F: Documentation/devicetree/bindings/power/apple* > F: arch/arm64/boot/dts/apple/ > F: drivers/irqchip/irq-apple-aic.c > F: include/dt-bindings/interrupt-controller/apple-aic.h > -- > 2.33.0 >
