Acer laptop brightness hal support

[Michal Majchrowicz]

On 9/7/07, Danny Kukawka <danny.kukawka at web.de> wrote:
> On Freitag, 7. September 2007, Michal Majchrowicz wrote:
> > Hi.
> > I recently spent some time on adding software way of controling
> > brightness on my Acer laptop. There is acer_acpi module that adds this
> > support. It creates /proc/acpi/acer/brightness which allows to
> > set/read brightness. I have modified acpi.c to add to hal support for
> > this module. I hope you will accept it to main tree. I don't send
> > hal-system-lcd* since the contol of brightness is almost the same as
> > for panasonic (and others).
> > to read:
> > cat /proc/acpi/acer/brightness
>
> Only some comments:
>
> 1) this driver isn't part ot the linux kernel?! Why?
>
> 2) I didn't read the complete code and docu of the driver, but if I understood
> everything correct: the driver should use the backlight interface of the
> kernel. Please check what 'grep . /sys/class/backlight/* -r' print. We should
> not support the absolute deprecated proc interface if there is support for
> the backlight interface.
>
> Danny
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>

Sorry about creating another thread it was not intentional :)
1) The support for this kind of things was previously added by acerhk
which uses 32 bit bios calls. However this approach will not work on
64 bit systems. Then the development of acer_acpi was started (which
doesn't use bios calls and therefore works on 64 bit systems). It uses
some WMI interface (I am not ACPI expert :)) and if I understand
correctly this technic is not implemented in main kernel tree (yet)
and this is why it is a seperated module. Everything is documented
here:
http://code.google.com/p/aceracpi/
2)Unfortunately I don't have any files/drectories in /sys/class/backlight :(
Regards Michal