From mboxrd@z Thu Jan 1 00:00:00 1970 From: ashwin.chaugule@linaro.org (Ashwin Chaugule) Date: Mon, 31 Mar 2014 11:02:58 -0400 Subject: [PATCH v4 2/3] Documentation: devicetree: Add new binding for PSCIv0.2 In-Reply-To: <1396278179-28181-1-git-send-email-ashwin.chaugule@linaro.org> References: <1396278179-28181-1-git-send-email-ashwin.chaugule@linaro.org> Message-ID: <1396278179-28181-3-git-send-email-ashwin.chaugule@linaro.org> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org The PSCI v0.2+ spec defines standard values for PSCI function IDs. Add a new binding entry so that pre v0.2 implementations can use DT entries for function IDs and v0.2+ implementations use standard entries as defined by the PSCIv0.2 specification. Signed-off-by: Ashwin Chaugule Acked-by: Rob Herring --- Documentation/devicetree/bindings/arm/psci.txt | 35 +++++++++++++++++++++++++- 1 file changed, 34 insertions(+), 1 deletion(-) diff --git a/Documentation/devicetree/bindings/arm/psci.txt b/Documentation/devicetree/bindings/arm/psci.txt index 433afe9..d01a90b 100644 --- a/Documentation/devicetree/bindings/arm/psci.txt +++ b/Documentation/devicetree/bindings/arm/psci.txt @@ -21,7 +21,15 @@ to #0. Main node required properties: - - compatible : Must be "arm,psci" + - compatible : should contain at least one of: + + * "arm,psci" : for implementations complying to PSCI versions prior to + 0.2. For these cases function IDs must be provided. + + * "arm,psci-0.2" : for implementations complying to PSCI 0.2. Function + IDs are not required and should be ignored by an OS with PSCI 0.2 + support, but are permitted to be present for compatibility with + existing software when "arm,psci" is later in the compatible list. - method : The method of calling the PSCI firmware. Permitted values are: @@ -45,6 +53,8 @@ Main node optional properties: Example: +Case 1: PSCI v0.1 only. + psci { compatible = "arm,psci"; method = "smc"; @@ -53,3 +63,26 @@ Example: cpu_on = <0x95c10002>; migrate = <0x95c10003>; }; + + +Case 2: PSCI v0.2 only + + psci { + compatible = "arm,psci-0.2"; + method = "smc"; + }; + +Case 3: PSCI v0.2 and PSCI v0.1. + + As described above, for compatibility with existing kernels, the + hypervisor will likely want to provide IDs, e.g. + + psci { + compatible = "arm,psci-0.2", "arm,psci"; + method = "hvc"; + + cpu_on = < arbitrary value >; + cpu_off = < arbitrary value >; + + ... + }; -- 1.8.3.2