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- Added Boolean property in info.plist "BQC use index" to be use if your _BQC returns an index to _BCL entries (not tested)
- Added an optional DSDT optimization : you can add a method SAVE with same parameters than _BCM and on the same device in order to split the DSDT code that set the backlight value in the PWM control register (usually located in EC) and the DSDT code that save the value in CMOS (usually in the RTC second bank of RAM : OperationRegion (xxxx, SystemIO, 0x72, 0x02) but triggered by a SMI interrupt to ensure CMOS checksum computation)
New version 1.1:
- Added : look at power supply status at start up
- Code correction : more checks on pointers and function return
This is a driver for laptops which backlight are controlled by ACPI Methods: if you have _DOS _BCL _BCM _BQC in you DSDT. A good reading for DSDT editing if need is Advanced Configuration and Power Interface (ACPI) Specification 4.0a APPENDIX B: Video Extensions.
This driver provides native backlight management for laptops with backlight managed by ACPI : slider in the display pref pane and sun bezel when you press backlight up/down hotkey (with an other driver than can understand your keyboard Fn keys...), power management by the OS : dim before sleep, reduce level when AC is unpluged.
sun_bezel.png 434.73K
458 downloads
display.png 52.46K
576 downloadsIt replaces an other driver I've written.ACPIBacklightDisplay.kext This old driver shall be removed.
Tested on SL 10.6.8 and Lion 10.7.0 to 10.7.2. May works on older version, but not tested.
Reported to work on 10.6.7.
Pre requested: having AppleBacklightDisplay loaded.
For this, you must have this properties injected among others by DSDT _DSM+DTGP (or graphics enabler ? or EFI strings...):
"AAPL,HasPanel",
Buffer (0x04)
{
0x01, 0x00, 0x00, 0x00
},
"AAPL,Haslid",
Buffer (0x04)
{
0x01, 0x00, 0x00, 0x00
},
"AAPL,backlight-control",
Buffer (0x04)
{
0x01, 0x00, 0x00, 0x00
},
"@0,backlight-control",
Buffer (0x04)
{
0x01, 0x00, 0x00, 0x00
},
"@0,AAPL,boot-display",
Buffer (0x04)
{
0x01, 0x00, 0x00, 0x00
},
"@0,built-in",
Buffer ()
{
One
},
It works for NVIDIA and Intel graphics. Seems problematic for some ATI users for the moment. (ATI is always more complicated!!)
There also must be this device in DSDT, in the \_SB scope:
Scope (\_SB)
{
...
Device (PNLF)
{
Name (_HID, EisaId ("APP0002"))
Name (_CID, "backlight")
Name (_UID, 0x0A)
Name (_STA, 0x0B)
}
...
}
If you don't have the _DOS Method, add a fake one in the GPU device (IGPU, GFX0... or what ever the name, it is the parent of the device where you find _BCL, _BQC, _BCM).
Method (_DOS, 1, NotSerialized)
{
//nothing to do
}
If you have several devices with _BCL _BCM _BQC the driver will take the first it finds, so you will have to find with one is the good one to do an other DSDT trick. For this locate in ioreg on with device the graphic driver is loaded. Then add this into PNLF:
Method (_BCL, 0, NotSerialized)
{
return (\_SB.PCI0.IXVE.IGPU.LCDD._BCL())
}
Method (_BCM, 1, NotSerialized)
{
\_SB.PCI0.IXVE.IGPU.LCDD._BCM(Arg0)
}
Method (_BQC, 0, NotSerialized)
{
return (\_SB.PCI0.IXVE.IGPU.LCDD._BQC())
}
Method (_DOS, 1, NotSerialized)
{
\_SB.PCI0.IXVE.IGPU._DOS(Arg0)
}
Replacing _SB.PCI0.IXVE.IGPU and _SB.PCI0.IXVE.IGPU.LCDD of my example with your good path.Then install this kext in S/L/E (with Kext Utility or similar !)
ACPIBacklight.kext.zip 21.75K
908 downloadsIf all goes right, you shall see this on the kernel log:
ACPIBacklightPanel: Found Backlight Device: LCDD
ACPIBacklightPanel: ACPI Method _DOS found. Device path: _SB.PCI0.IXVE.IGPU
ACPIBacklightPanel: ACPI Methods _BCL _BCM _BQC found. Device path: _SB.PCI0.IXVE.IGPU.LCDD
ACPIBacklightPanel: Version 1.0
Source:
ACPIBacklight.kext_src.zip 27.98K
269 downloads
