From mboxrd@z Thu Jan 1 00:00:00 1970 From: Niklas Cassel Subject: [RFC PATCH 7/9] dt-bindings: power: avs: Add support for CPR (Core Power Reduction) Date: Thu, 4 Apr 2019 07:09:28 +0200 Message-ID: <20190404050931.9812-8-niklas.cassel@linaro.org> References: <20190404050931.9812-1-niklas.cassel@linaro.org> Mime-Version: 1.0 Content-Transfer-Encoding: 8bit Return-path: In-Reply-To: <20190404050931.9812-1-niklas.cassel@linaro.org> Sender: linux-kernel-owner@vger.kernel.org To: Rob Herring , Mark Rutland , Jorge Ramirez-Ortiz , Niklas Cassel Cc: linux-arm-msm@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org List-Id: devicetree@vger.kernel.org Add DT bindings to describe the CPR HW found on certain Qualcomm SoCs. Co-developed-by: Jorge Ramirez-Ortiz Signed-off-by: Jorge Ramirez-Ortiz Signed-off-by: Niklas Cassel --- .../bindings/power/avs/qcom,cpr.txt | 119 ++++++++++++++++++ 1 file changed, 119 insertions(+) create mode 100644 Documentation/devicetree/bindings/power/avs/qcom,cpr.txt diff --git a/Documentation/devicetree/bindings/power/avs/qcom,cpr.txt b/Documentation/devicetree/bindings/power/avs/qcom,cpr.txt new file mode 100644 index 000000000000..541c9b31cd3b --- /dev/null +++ b/Documentation/devicetree/bindings/power/avs/qcom,cpr.txt @@ -0,0 +1,119 @@ +QCOM CPR (Core Power Reduction) + +CPR (Core Power Reduction) is a technology to reduce core power on a CPU +or other device. Each OPP of a device corresponds to a "corner" that has +a range of valid voltages for a particular frequency. While the device is +running at a particular frequency, CPR monitors dynamic factors such as +temperature, etc. and suggests adjustments to the voltage to save power +and meet silicon characteristic requirements. + +- compatible: + Usage: required + Value type: + Definition: must be "qcom,cpr" + +- reg: + Usage: required + Value type: + Definition: base address and size of the rbcpr register region + +- interrupts: + Usage: required + Value type: + Definition: list of three interrupts in order of irq0, irq1, irq2 + +- acc-syscon: + Usage: optional + Value type: + Definition: phandle to syscon for writing ACC settings + +- nvmem: + Usage: required + Value type: + Definition: phandle to nvmem provider containing efuse settings + +- nvmem-names: + Usage: required + Value type: + Definition: must be "qfprom" + +vdd-mx-supply = <&pm8916_l3>; + +- qcom,cpr-ref-clk: + Usage: required + Value type: + Definition: rate of reference clock in kHz + +- qcom,cpr-timer-delay-us: + Usage: required + Value type: + Definition: delay in uS for the timer interval + +- qcom,cpr-timer-cons-up: + Usage: required + Value type: + Definition: Consecutive number of timer intervals, or units of + qcom,cpr-timer-delay-us, that occur before issuing an up + interrupt + +- qcom,cpr-timer-cons-down: + Usage: required + Value type: + Definition: Consecutive number of timer intervals, or units of + qcom,cpr-timer-delay-us, that occur before issuing a down + interrupt + +- qcom,cpr-up-threshold: + Usage: optional + Value type: + Definition: The threshold for CPR to issue interrupt when error_steps + is greater than it when stepping up + +- qcom,cpr-down-threshold: + Usage: optional + Value type: + Definition: The threshold for CPR to issue interrdownt when error_steps + is greater than it when stepping down + +- qcom,cpr-down-threshold: + Usage: optional + Value type: + Definition: Idle clock cycles ring oscillator can be in + +- qcom,cpr-gcnt-us: + Usage: required + Value type: + Definition: The time for gate count in uS + +- qcom,vdd-apc-step-up-limit: + Usage: required + Value type: + Definition: Limit of vdd-apc-supply steps for scaling up + +- qcom,vdd-apc-step-down-limit: + Usage: required + Value type: + Definition: Limit of vdd-apc-supply steps for scaling down + +Example: + + avs@b018000 { + compatible = "qcom,cpr"; + reg = <0xb018000 0x1000>; + interrupts = <0 15 1>, <0 16 1>, <0 17 1>; + vdd-mx-supply = <&pm8916_l3>; + acc-syscon = <&tcsr>; + nvmem = <&qfprom>; + nvmem-names = "qfprom"; + + qcom,cpr-ref-clk = <19200>; + qcom,cpr-timer-delay-us = <5000>; + qcom,cpr-timer-cons-up = <0>; + qcom,cpr-timer-cons-down = <2>; + qcom,cpr-up-threshold = <0>; + qcom,cpr-down-threshold = <2>; + qcom,cpr-idle-clocks = <15>; + qcom,cpr-gcnt-us = <1>; + qcom,vdd-apc-step-up-limit = <1>; + qcom,vdd-apc-step-down-limit = <1>; + }; -- 2.20.1