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platform/x86: lenovo-wmi-capdata: Wire up Fan Test Data

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A capdata00 attribute (0x04050000) describes the presence of Fan Test
Data. Query it, and bind Fan Test Data as a component of capdata00
accordingly. The component master of capdata00 may pass a callback while
binding to retrieve fan info from Fan Test Data.

Summarizing this scheme:

	lenovo-wmi-other <-> capdata00 <-> capdata_fan
	|- master            |- component  |
	                     |- sub-master |- sub-component

The callback will be called once both the master and the sub-component
are bound to the sub-master (component).

This scheme is essential to solve these issues:
- The component framework only supports one aggregation per master
- A binding is only established until all components are found
- The Fan Test Data interface may be missing on some devices
- To get rid of queries for the presence of WMI GUIDs
- The notifier framework cannot cleanly connect capdata_fan to
  lenovo-wmi-other without introducing assumptions on probing sequence

capdata00 is registered as a component and a sub-master on probe,
instead of chaining the registrations in one's bind callback. This is
because calling (un)registration methods of the component framework
causes deadlock in (un)bind callbacks, i.e., it's impossible to register
capdata00 as a sub-master/component in its component/sub-master bind
callback, and vice versa.

Signed-off-by: Rong Zhang <i@rong.moe>
Reviewed-by: Derek J. Clark <derekjohn.clark@gmail.com>
Tested-by: Derek J. Clark <derekjohn.clark@gmail.com>
Link: https://patch.msgid.link/20260120182104.163424-7-i@rong.moe
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
This commit is contained in:
Rong Zhang 2026-01-21 02:20:07 +08:00 • committed by Ilpo Järvinen
commit 67d9a39ce8
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