Change Details

Attaching syscon_generic earlier than BUS_PASS_DEFAULT makes it more difficult for specific syscon drivers to attach to the syscon node and to get ordering right. Further discussion yielded the following set of decisions: - Move syscon_generic to BUS_PASS_DEFAULT - If a platform needs a syscon with different attach order or probe behavior , it should subclass syscon_generic and match on the SoC specific compat string - When we come across a need for a syscon that attaches earlier but only specifies compatible = "syscon", we should create a syscon_exclusive driver that provides generic access but probes earlier and only matches if "syscon" is the only compatible. Such fdt nodes do exist in the wild right now, but we don't really use them at the moment. Additionally: - Any syscon provider that has needs any more complex than a spinlock solely for syscon access and a single memory resource should subclass syscon directly rather than attempting to subclass syscon_generic or add complexity to it. Introduce aw_syscon(4) that just uses syscon_generic's attach/detach methods but probes earlier to meet our requirements for if_awg and effectively implements #2 above for this specific situation. It currently only matches a64/a83t/h3 since these are the only platforms that really need it at the time being.

Attaching syscon_generic earlier than BUS_PASS_DEFAULT makes it more difficult for specific syscon drivers to attach to the syscon node and to get ordering right. Further discussion yielded the following set of decisions: - Move syscon_generic to BUS_PASS_DEFAULT - If a platform needs a syscon with different attach order or probe behavior , it should subclass syscon_generic and match on the SoC specific compat string - When we come across a need for a syscon that attaches earlier but only specifies compatible = "syscon", we should create a syscon_exclusive driver that provides generic access but probes earlier and only matches if "syscon" is the only compatible. Such fdt nodes do exist in the wild right now, but we don't really use them at the moment. Additionally: - Any syscon provider that has needs any more complex than a spinlock solely for syscon access and a single memory resource should subclass syscon directly rather than attempting to subclass syscon_generic or add complexity to it. syscon_generic's attach/detach methods may be made public should the need arise to subclass it with additional attach/detach behavior. Introduce aw_syscon(4) that just subclasses syscon_generic but probes earlier to meet our requirements for if_awg and implements #2 above for this specific situation. It currently only matches a64/a83t/h3 since these are the only platforms that really need it at the time being.

Attaching syscon_generic earlier than BUS_PASS_DEFAULT makes it more difficult for specific syscon drivers to attach to the syscon node and to get ordering right. Further discussion yielded the following set of decisions: - Move syscon_generic to BUS_PASS_DEFAULT - If a platform needs a syscon with different attach order or probe behavior , it should subclass syscon_generic and match on the SoC specific compat string - When we come across a need for a syscon that attaches earlier but only specifies compatible = "syscon", we should create a syscon_exclusive driver that provides generic access but probes earlier and only matches if "syscon" is the only compatible. Such fdt nodes do exist in the wild right now, but we don't really use them at the moment. Additionally: - Any syscon provider that has needs any more complex than a spinlock solely for syscon access and a single memory resource should subclass syscon directly rather than attempting to subclass syscon_generic or add complexity to it. syscon_generic's attach/detach methods may be made public should the need arise to subclass it with additional attach/detach behavior. Introduce aw_syscon(4) that just usubclasses syscon_generic's attach/detach methodsc but probes earlier to meet our requirements for if_awg and effectively implements #2 above for this specific situation. It currently only matches a64/a83t/h3 since these are the only platforms that really need it at the time being.