[Gta04-owner] Linux 3.2-rc3 on GTA04

[Christoph Mair]

On Sat, Nov 26, 2011 at 12:43 PM, NeilBrown <neilb at suse.de> wrote:

>  - Brand new driver for the LEDs (tca6507] [2]
>  - Backlight control with PWM - untested [3]

>  2/ My new from-scratch driver for leds-tca6507 provides full support for
>    setting brightness levels and hardware-assisted blinking, all through the
>    standard /sys/class/leds/* interface.  The leds are given names:
>       gta04:{red,green}:{aux,power}
>    (no blue LED - I'm sad :-)
This works fine, also with triggers (for charging and SD access).

>    The driver can also make lines appear as GPIO output.  The Wifi reset now
>    appears as /sys/class/gpio/WiFi-Reset
>    (I haven't tested it though).


>  3/ I included the PWM (Pulse Width Modulation) driver that Nikolaus mentions
>    in http://projects.goldelico.com/p/gta04-kernel/issues/85/ and figured
>    out how to link it up with the backlight function.
>
>    I've checked that 'setterm -blank force' and 'setterm -blank poke' cause
>    the PWM module to request different pulse widths, but I don't know if
>    it is actually affecting the backlight (because I don't have one plugged
>    in).
>    Test reports would be most welcome.

Changing the brightness using
/sys/class/backlight/pwm-backlight/brightness works great. Values
between 12 and 100 do enable and dim the backlight. With values <= 11
the display stays dark.

Best regards,
  Christoph