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From: "James H. Cloos Jr." <cloos-GRsvFm/Gh/pBDgjK7y7TUQ@public.gmane.org>
To: acpi-devel-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org
Subject: lcd backlight
Date: 12 Jul 2003 21:34:35 -0400	[thread overview]
Message-ID: <m365m7jjkk.fsf@lugabout.jhcloos.org> (raw)

A bios setting causes a regular screen blank, but w/ acpi the lcd's
backlight is left on.  

The following function (based on 's radeontools) controls the
backlight perfectly:

void radeon_cmd_light(int param)
{
    unsigned long dac_cntl;

    dac_cntl = radeon_get(RADEON_LVDS_GEN_CNTL,"RADEON_LVDS_GEN_CNTL");
    if(param != 0) {
        dac_cntl |= RADEON_LVDS_ON;
    } else {
        dac_cntl &= ~ RADEON_LVDS_ON;
    }
    radeon_set(RADEON_LVDS_GEN_CNTL,"RADEON_LVDS_GEN_CNTL",dac_cntl);
}


What needs to be done, given this info on how to control the
backlight and the bios's dsdt, to convince the kernel to toggle
the backlight when the screen blanks?

-JimC



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             reply	other threads:[~2003-07-13  1:34 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2003-07-13  1:34 James H. Cloos Jr. [this message]
     [not found] ` <m365m7jjkk.fsf-eUECQUGGJJCHAtaq1fIXeWD2FQJk+8+b@public.gmane.org>
2003-07-13  4:11   ` lcd backlight Jonathan Steinert

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