Thank Gregory.
It looks like very few NuttX-supported processor architectures have any
power modes implemented, but looks like maybe one or 2, plus many others
with "not yet implemented" comments (now I know what to look for).
I will have a look at what is included in builds when CONFIG_PM is
enabled, and try and find some "hooks" that give me clues as to how to
add code to the SAMA5D2 arch code.
On 11/10/2025 13:25, Gregory Nutt wrote:
The are no and special arch/board drivers. There could be, of course, but they
are not required by the PM subsystem.
Low-power mode is done via the PM subsystem and the regular drivers. It is a
subscibe/notify design. Each regular driver registers for PM call backs and/or
generates PM notifications. The relevant calls are prototyped in
include/nuttx/power/pm.h.
The high level, coordinating logic is in drivers/power/pm.
Example usage is in architectures whose drivers call pm_register(). That sets
up the driver to receive PM event notifications.
Some older references:
https://cwiki.apache.org/confluence/display/NUTTX/Power+Management+-+Final+Report
https://cwiki.apache.org/confluence/display/NUTTX/Porting+Guide#pwrmgmt
And probably others in the old Wiki (that predate Apache NuttX).
________________________________
From: Tim Hardisty <[email protected]>
Sent: Saturday, October 11, 2025 3:00 AM
To: [email protected] <[email protected]>
Subject: low power mode drivers?
Hello all.
I want to put a SAMA5D2 processor into low power modes via a software
function call. I have found some Microchip App Notes but they either
refer to Linux or have pseudo code for bare-metal, but I sort of
understand what the functions will need to do.
Can someone point me to where in NuttX such arch/board drivers should
live and/or the methodology/template/whatever to use? Then I can find a
board or arch I can use as a reference.
Probably staring me in the face but can't see anything appropriate as yet!
Thanks!
