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author | Yunhong Jiang <yunhong.jiang@intel.com> | 2015-08-04 12:17:53 -0700 |
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committer | Yunhong Jiang <yunhong.jiang@intel.com> | 2015-08-04 15:44:42 -0700 |
commit | 9ca8dbcc65cfc63d6f5ef3312a33184e1d726e00 (patch) | |
tree | 1c9cafbcd35f783a87880a10f85d1a060db1a563 /kernel/Documentation/devicetree/bindings/arm/psci.txt | |
parent | 98260f3884f4a202f9ca5eabed40b1354c489b29 (diff) |
Add the rt linux 4.1.3-rt3 as base
Import the rt linux 4.1.3-rt3 as OPNFV kvm base.
It's from git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git linux-4.1.y-rt and
the base is:
commit 0917f823c59692d751951bf5ea699a2d1e2f26a2
Author: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Date: Sat Jul 25 12:13:34 2015 +0200
Prepare v4.1.3-rt3
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
We lose all the git history this way and it's not good. We
should apply another opnfv project repo in future.
Change-Id: I87543d81c9df70d99c5001fbdf646b202c19f423
Signed-off-by: Yunhong Jiang <yunhong.jiang@intel.com>
Diffstat (limited to 'kernel/Documentation/devicetree/bindings/arm/psci.txt')
-rw-r--r-- | kernel/Documentation/devicetree/bindings/arm/psci.txt | 102 |
1 files changed, 102 insertions, 0 deletions
diff --git a/kernel/Documentation/devicetree/bindings/arm/psci.txt b/kernel/Documentation/devicetree/bindings/arm/psci.txt new file mode 100644 index 000000000..5aa40ede0 --- /dev/null +++ b/kernel/Documentation/devicetree/bindings/arm/psci.txt @@ -0,0 +1,102 @@ +* Power State Coordination Interface (PSCI) + +Firmware implementing the PSCI functions described in ARM document number +ARM DEN 0022A ("Power State Coordination Interface System Software on ARM +processors") can be used by Linux to initiate various CPU-centric power +operations. + +Issue A of the specification describes functions for CPU suspend, hotplug +and migration of secure software. + +Functions are invoked by trapping to the privilege level of the PSCI +firmware (specified as part of the binding below) and passing arguments +in a manner similar to that specified by AAPCS: + + r0 => 32-bit Function ID / return value + {r1 - r3} => Parameters + +Note that the immediate field of the trapping instruction must be set +to #0. + + +Main node required properties: + + - 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: + + "smc" : SMC #0, with the register assignments specified + in this binding. + + "hvc" : HVC #0, with the register assignments specified + in this binding. + +Main node optional properties: + + - cpu_suspend : Function ID for CPU_SUSPEND operation + + - cpu_off : Function ID for CPU_OFF operation + + - cpu_on : Function ID for CPU_ON operation + + - migrate : Function ID for MIGRATE operation + +Device tree nodes that require usage of PSCI CPU_SUSPEND function (ie idle +state nodes, as per bindings in [1]) must specify the following properties: + +- arm,psci-suspend-param + Usage: Required for state nodes[1] if the corresponding + idle-states node entry-method property is set + to "psci". + Value type: <u32> + Definition: power_state parameter to pass to the PSCI + suspend call. + +Example: + +Case 1: PSCI v0.1 only. + + psci { + compatible = "arm,psci"; + method = "smc"; + cpu_suspend = <0x95c10000>; + cpu_off = <0x95c10001>; + 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. + + A DTB may provide IDs for use by kernels without PSCI 0.2 support, + enabling firmware and hypervisors to support existing and new kernels. + These IDs will be ignored by kernels with PSCI 0.2 support, which will + use the standard PSCI 0.2 IDs exclusively. + + psci { + compatible = "arm,psci-0.2", "arm,psci"; + method = "hvc"; + + cpu_on = < arbitrary value >; + cpu_off = < arbitrary value >; + + ... + }; + +[1] Kernel documentation - ARM idle states bindings + Documentation/devicetree/bindings/arm/idle-states.txt |