[PATCH V3 0/6] ARM64: Add support for FSL's LS2085A SoC
Stuart Yoder
stuart.yoder at freescale.com
Wed Sep 24 07:50:04 PDT 2014
So there is still an open issue that has not been closed related to
what device trees should have with respect to enable-method. There
are 2 proposals from Mark and Arnd--
1. Put comment in /cpus node in dts (Mark)
...
cpus {
#address-cells = <2>;
#size-cells = <0>;
/*
* We expect the enable-method to be "psci", but this is dependent on
* the FW, which will fill this in.
*/
cpu at 0 {
device_type = "cpu";
compatible = "arm,cortex-a57";
reg = <0x0 0x0>;
};
...
2. Put explicit psci enable-method in cpu nodes, to make it clear that psci
is expected. Plus include empty psci node with a comment. (Arnd)
...
/*
* We expect the enable-method to be "psci", but this is dependent on
* the FW, which will fill this in.
*/
psci {
}
...
cpus {
#address-cells = <2>;
#size-cells = <0>;
cpu at 0 {
device_type = "cpu";
compatible = "arm,cortex-a57";
reg = <0x0 0x0>;
enable-method = "psci";
};
...
I would prefer #1. I think putting "hints" like the psci node and
the enable-method are weak at best. I think the comment in #1 is
enough to make the preferred approach clear. In the end firmware will
override the nodes and properties if it wants or needs to.
Thanks,
Stuart
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