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55 lines
1.7 KiB
Markdown
55 lines
1.7 KiB
Markdown
# Fixing Trackpads
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This SSDT is used to force enable our GPI0 for VoodooI2C to connect onto.
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With most modern laptop DSDTs, there's a variable called `GPEN` or `GPHD` which are used for setting the status of the GPI0 device. For us, we want to enable the device.
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## Finding our GPI0
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So first things we need to do is find out what variable is used to enable our GPI0 device, lets open up our decompiled SSDT and search for `Device (GPI0)`. Should give you a desult similar to this:
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What we care about from this is the `_STA` method:
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```
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Method (_STA, 0, NotSerialized)
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{
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If ((GPHD == One))
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{
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Return (0x03)
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}
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Return (0x0F)
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}
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```
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What we want is for this to always return `0x0F` when booting macOS, so we want to make an SSDT that will return `GPHD == Zero` in macOS.
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**NOTE that you may have the other way around where GPHD needs to be set as `One` to return `0x0F`**. And your device name may also be different, don't throw random SSDTs in thinking it'll work
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Once you found the variable and what it should be set to, grab a copy of [SSDT-GPI0.dsl](https://github.com/dortania/Getting-Started-With-ACPI/blob/master/extra-files/SSDT-GPI0.dsl) and make the required edits. Then clean up with compiling it
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## More examples
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With this example, we can see that we need both `SBRG` and `GPEN` to return `One`. If only one is present, it'll create some issues so in our SSDT we'll want to have both of them return `One`:
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```
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DefinitionBlock("", "SSDT", 2, "ACDT", "GPI0", 0)
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{
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External(GPEN, FieldUnitObj)
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External(SBRG, FieldUnitObj)
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Scope (\)
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{
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If (_OSI ("Darwin"))
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{
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GPEN = One
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SBRG = One
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}
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}
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}
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```
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