Add helpers in the generic PHY folder which can be used using 'select
PHY_COMMON_PROPS' from Kconfig, without otherwise needing to
enable GENERIC_PHY.
These helpers need to deal with the slight messiness of the fact that
the polarity properties are arrays per protocol, and with the fact that
there is no default value mandated by the standard properties, all
default values depend on driver and protocol (PHY_POL_NORMAL may be a
good default for SGMII, whereas PHY_POL_AUTO may be a good default for
PCIe).
Push the supported mask of polarities to these helpers, to simplify
drivers such that they don't need to validate what's in the device tree
(or other firmware description).
Add a KUnit test suite to make sure that the API produces the expected
results. The fact that we use fwnode structures means we can validate
with software nodes, and as opposed to the device_property API, we can
bypass the need to have a device structure.
Co-developed-by: Bjørn Mork <bjorn@mork.no>
Signed-off-by: Bjørn Mork <bjorn@mork.no>
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Link: https://patch.msgid.link/20260111093940.975359-6-vladimir.oltean@nxp.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
e7556b59ba