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ab16dfb99c
On newer Airoha SoC, CPU Frequency is scaled indirectly with SMC commands to ATF. A virtual clock is exposed. This virtual clock is a get-only clock and is used to expose the current global CPU clock. The frequency info comes by the output of the SMC command that reports the clock in MHz. The SMC sets the CPU clock by providing an index, this is modelled as performance states in a power domain. CPUs can't be individually scaled as the CPU frequency is shared across all CPUs and is global. Signed-off-by: Christian Marangi <ansuelsmth@gmail.com> Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org> Reviewed-by: Rob Herring (Arm) <robh@kernel.org> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
56 lines
1.3 KiB
YAML
56 lines
1.3 KiB
YAML
# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
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%YAML 1.2
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---
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$id: http://devicetree.org/schemas/cpufreq/airoha,en7581-cpufreq.yaml#
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$schema: http://devicetree.org/meta-schemas/core.yaml#
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title: Airoha EN7581 CPUFreq
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maintainers:
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- Christian Marangi <ansuelsmth@gmail.com>
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description: |
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On newer Airoha SoC, CPU Frequency is scaled indirectly with SMC commands
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to ATF.
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A virtual clock is exposed. This virtual clock is a get-only clock and
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is used to expose the current global CPU clock. The frequency info comes
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by the output of the SMC command that reports the clock in MHz.
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The SMC sets the CPU clock by providing an index, this is modelled as
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performance states in a power domain.
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CPUs can't be individually scaled as the CPU frequency is shared across
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all CPUs and is global.
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properties:
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compatible:
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const: airoha,en7581-cpufreq
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'#clock-cells':
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const: 0
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'#power-domain-cells':
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const: 0
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operating-points-v2: true
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required:
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- compatible
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- '#clock-cells'
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- '#power-domain-cells'
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- operating-points-v2
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additionalProperties: false
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examples:
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- |
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performance-domain {
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compatible = "airoha,en7581-cpufreq";
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operating-points-v2 = <&cpu_smcc_opp_table>;
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#power-domain-cells = <0>;
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#clock-cells = <0>;
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};
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