[Nut-upsdev] naming a new Mac OS X UPS driver

Charles Lepple clepple at gmail.com
Sat Aug 27 23:42:32 UTC 2011

On Aug 27, 2011, at 6:46 AM, Arnaud Quette wrote:

> this is very similar to the HAL / UPower (using the system provided  
> PM integration)!
> but you have a converse approach: consume data from this source.
> does this means that using this source is better (in terms of data  
> and features provided)?

Fewer features, but easier to implement. It's really more of a  
monitoring interface, since the OS GUI provides a number of different  
shutdown thresholds.

> and / or that NUT drivers can't replace (as with UPower) OS X' one(s)?

This is what got me looking at HIDAPI: the HID driver in OS X makes it  
hard to grab a HID device/interface with libhid.

Then again, since HIDAPI doesn't deal with HID usage paths, I might be  
able to code up some alternate HID stuff for NUT that uses the native  
OS X HID interface now that I'm a bit more familiar with that code. I  
need a sabbatical :-)

> is this still limited to USB HID?

I think the OS only supports USB HID, but it would be possible to  
write a bridge that goes the other way to let the OS see UPS status  
for a serial or network UPS. I think it would be best implemented as  
an upsd client.

> my last idea on UPower (and similar needs) was to change the driver  
> dstate layer (which is used for communication with upsd) to a plugin  
> system style. the default would still be to load the classic dstate.  
> but alternative would be provided for DBus / UPower and any other  
> kind of useful protocols.

Personal preference: I don't like plugin interfaces where only one  
interface is used at a time. The HAL drivers just linked in a  
different dstate layer at compile time - wouldn't that work?

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