Adding bindings to represent a virtual cpufreq device. Virtual machines may expose MMIO regions for a virtual cpufreq device for guests to read performance information or to request performance selection. The virtual cpufreq device has an individual controller for each performance domain. Performance points for a given domain can be normalized across all domains for ease of allowing for virtual machines to migrate between hosts. Co-developed-by: Saravana Kannan <saravanak@xxxxxxxxxx> Signed-off-by: Saravana Kannan <saravanak@xxxxxxxxxx> Signed-off-by: David Dai <davidai@xxxxxxxxxx> --- .../cpufreq/qemu,virtual-cpufreq.yaml | 48 +++++++++++++++++++ 1 file changed, 48 insertions(+) create mode 100644 Documentation/devicetree/bindings/cpufreq/qemu,virtual-cpufreq.yaml diff --git a/Documentation/devicetree/bindings/cpufreq/qemu,virtual-cpufreq.yaml b/Documentation/devicetree/bindings/cpufreq/qemu,virtual-cpufreq.yaml new file mode 100644 index 000000000000..018d98bcdc82 --- /dev/null +++ b/Documentation/devicetree/bindings/cpufreq/qemu,virtual-cpufreq.yaml @@ -0,0 +1,48 @@ +# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause +%YAML 1.2 +--- +$id: http://devicetree.org/schemas/cpufreq/qemu,virtual-cpufreq.yaml# +$schema: http://devicetree.org/meta-schemas/core.yaml# + +title: Virtual CPUFreq + +maintainers: + - David Dai <davidai@xxxxxxxxxx> + - Saravana Kannan <saravanak@xxxxxxxxxx> + +description: + Virtual CPUFreq is a virtualized driver in guest kernels that sends performance + selection of its vCPUs as a hint to the host through MMIO regions. Each vCPU + is associated with a performance domain which can be shared with other vCPUs. + Each performance domain has its own set of registers for performance controls. + +properties: + compatible: + const: qemu,virtual-cpufreq + + reg: + maxItems: 1 + description: + Address and size of region containing performance controls for each of the + performance domains. Regions for each performance domain is placed + contiguously and contain registers for controlling DVFS(Dynamic Frequency + and Voltage) characteristics. The size of the region is proportional to + total number of performance domains. + +required: + - compatible + - reg + +additionalProperties: false + +examples: + - | + soc { + #address-cells = <1>; + #size-cells = <1>; + + cpufreq@1040000 { + compatible = "qemu,virtual-cpufreq"; + reg = <0x1040000 0x2000>; + }; + }; -- 2.45.0.215.g3402c0e53f-goog
