MLK-21287 soc: imx: keep resource power ON if subdomain is wakeup source
The power mode operation ONLY checks whether the resource being
powered OFF is a wakeup source, and skip power OFF operation if
it is a wakeup source, but it does NOT consider the power tree
status, if any of its children is a wakeup source, it needs to
be kept powered ON for its children's wakeup capability.
For example, on i.MX8QXP, CAN1 shares CAN0's power, if CAN1 is
enabled as wakeup source, CAN0's power needs to be ON even it
is NOT a wakeup source, this patch adds support for such scenario.
As it uses recursion, to avoid overhead during runtime power
management, introduce a variable to make sure this logic is ONLY
enabled during suspend/resume.
The generic power domain framework for handling device power
according to wakeup status does NOT consider the virtual devices,
e.g., if debug uart is enabled as wakeup source, the device wakeup
capability check for uart device returns false, ONLY the ttydev has
wakeup capability, that will cause resume_needed() return false
and uart device power will be OFF even its child device "ttydev" is
enabeld as wakeup source.
Signed-off-by: Anson Huang <Anson.Huang@nxp.com>
Tested-by: Joakim Zhang <qiangqing.zhang@nxp.com>
Reviewed-by: Bai Ping <ping.bai@nxp.com>
(cherry picked from commit
459db9c5f53735f33753a7a60232784b3d09d261)