Re: a question about lid input device

[Dmitry Torokhov <dmitry.torokhov@gmail.com>]

On Mon, Jun 21, 2010 at 09:56:37PM -0400, Len Brown wrote:
> Dmitry,
> Is there a reason not to simply add a "state" attribute
> to a LID input device?
> 

Len,

There is no LED input device, there is an input device that happens to
report EV_SW/SW_LID state. If we did that we'd need to add attributes
for all types of switches, keys, current values of REL and ABS axis,
min/max/fuzz/flat settings of ABS axis and so forth that input device
might report. I do not think it is a good idea.

> 
> thanks,
> Len Brown, Intel Open Source Technology Center
> 
> On Sun, 13 Jun 2010, Henrique de Moraes Holschuh wrote:
> 
> > On Sun, 13 Jun 2010, Zhang Rui wrote:
> > > Then we update the lid switch status when a Lid notification comes.
> > > right?
> > 
> > Yes.
> > 
> > > Then, IMO, userspace can get the lid status
> > > via /sys/class/input/inputX/uevent, right?
> > 
> > No, only through an IOCTL.
> > 
> > > /sys/class/input/input1/uevent:EV==21
> > 
> > That's an bitmap of al EV_EV it supports.
> > 
> > > /sys/class/input/input1/uevent:SW==1
> > 
> > That's an bitmap of al EV_SW it supports.
> > 
> > > Lid is opened but SW is set, I tried to close/open the lid and found
> > > that this bit never changes. is there something I misunderstand? can we
> > > get the lid status in userspace?
> > 
> > IOCTL(), only.
> > 
> > Since nobody got a input-utils standard package (or added something to
> > util-linux) yet to do that (AFAIK anyway), it is a MAJOR annoyance for
> > shell scripts that want to query EV_SW state...
> > 
> 

-- 
Dmitry