On Thu, Oct 11, 2012 at 5:41 AM, Christopher Heiny [off-list ref] wrote:
Linus Walleij wrote:
quoted
On Sat, Oct 6, 2012 at 6:09 AM, Christopher Heiny [off-list ref] wrote:
quoted
quoted
+ chargerinput ... (rw) User space programs can use this to tell
the + sensor that the system is plugged into an external
power + source (as opposed to running on
batteries). This allows + the sensor firmware to make
necessary adjustments for the + current capacitence
regime. Write 1 to this when the + system is using
external power, write 0 to this when the + system is
running on batteries. See spec for full details.
I remember discussing in-kernel notifiers for this. I don't
really see the point in tunnelling a notification from the drivers/power
subsystem to the drivers/input subsystem through userspace for
no good.
It's no blocker though, I don't expect you to fix this as part of
this driver submission.
Maybe Anton can comment?
Hmmm. I agree that it'd be good to avoid looping through userspace. But....
I found ways to notfiy the kernel that the charger is plugged/unplugged,
but that's only useful if you're a battery charger device driver. I also
found ways for userspace to get notification of charger events. I
didn't spot any way for in-kernel drivers to get notification of such
events. Perhaps I'm not looking the right places, though - can you
provide a pointer?
So my point was that there is indeed no such in-kernel
notification mechanism.
Maybe something engineered similar to this:
http://www.spinics.net/lists/lm-sensors/msg33834.html
Yours,
Linus Walleij