Finish GPI0 section (kinda)

Laptops/trackpad-methods/manual.md

@@ -1,16 +1,48 @@
 # Fixing Trackpads: Manual
 
-* [Finding the ACPI path](#finding-the-acpi-path)
+* [Checking GPI0](#checking-gpio)
 * [Edits to the sample SSDT](#edits-to-the-sample-ssdt)
 * [Compiling the SSDT](#compiling-the-ssdt)
 * [Wrapping up](#wrapping-up)
 
-## Finding the ACPI path
 
-Finding the ACPI pathing is quite easy actually, first open your decompiled DSDT you got from [Dumping the DSDT](/Manual/dump.md) and [Decompiling and Compiling](/Manual/compile.md) with either MaciASL(if in macOS) or any other text editor if in Windows or Linux(VSCode has an [ACPI extension](https://marketplace.visualstudio.com/items?itemName=Thog.vscode-asl) that can also help).
+## Checking GPI0
+
+The first thing which should be checked is the GPI0 device, which is required for VoodooI2C. The best way to check this is working is to use IORegistryViewer.
+
+![]()
+
+Here, we can see that VoodooI2C is attached to GPI0 so no edits are needed for GPI0 and you can skip to the next section.
+
+If VoodooI2C isn't attached, then you may need to set `GPEN` or other variable to make sure GPI0 is enabled. In that case, you will need to find the GPI0 device in ACPI.
+
+First open your decompiled DSDT you got from [Dumping the DSDT](/Manual/dump.md) and [Decompiling and Compiling](/Manual/compile.md) with either maciASL(if in macOS) or any other text editor if in Windows or Linux(VSCode has an [ACPI extension](https://marketplace.visualstudio.com/items?itemName=Thog.vscode-asl) that can also help).
 
 Next search for `Device (GPI0)`. Should give you a result similar to this:
 
+![](../../images/Laptops/trackpad-md/gpi0-2.png)
+
+We can see that `_STA` method, which enables or disable the GPI0 device:
+
+```
+Method (_STA, 0, NotSerialized)
+{
+    If ((SBRG == Zero))
+    {
+        Return (Zero)
+    }
+
+    If ((GPEN == Zero))
+    {
+        Return (Zero)
+    }
+
+    Return (0x0F)
+}
+
+We want the value of _STA to be 0x0F, as 0x00 (Zero) would disable the device. This checks two values, `SBRG` and `GPEN`. If either `SBRG` or `GPEN` is equal to zero, then zero will be returned. Generally, `SBRG` should not be modified as it will be correct already, and modifying it can break the `GPI0` device. If `GPI0` needs to be enabled, only modify the `GPEN` value.
+
+Here's some more examples:
 ![](../../images/Laptops/trackpad-md/gpi0.png)
 
 What we care about from this is the `_STA` method:
@@ -31,21 +63,13 @@ What we want is for this to always return `0x0F` when booting macOS, so we want
 
 **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
 
-Here's some more examples:
-
-![](../../images/Laptops/trackpad-md/gpi0-2.png)
-
-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`:
-
 ## Edits to the sample SSDT
 
 Now that we have our ACPI path, lets grab our SSDT and get to work:
 
 * [SSDT-GPI0.dsl](https://github.com/dortania/Getting-Started-With-ACPI/blob/master/extra-files/decompiled/SSDT-GPI0.dsl)
 
-From the second example, we'll want to set both GPEN and SBRG to `One` to allow it to operate in macOS:
+From the first example, we'll want to set GPEN to `One` to allow it to operate in macOS:
-
-**Before**:
 
 ```
 If (_OSI ("Darwin"))
@@ -54,31 +78,11 @@ If (_OSI ("Darwin"))
 }
 ```
 
-![](../../images/Laptops/trackpad-md/ssdt-before.png)
-
-Following the example pathing we found, the SSDT should look something like this:
-
-**After**:
-
-```
-
-External(GPEN, FieldUnitObj) <- Declare the right variables
-External(SBRG, FieldUnitObj) <- Declare the right variables
-
-Scope (\)
-{
-    If (_OSI ("Darwin"))
-    {
-        GPEN = One <- Change to the right variables
-        SBRG = One <- Change to the right variables
-    }
-```
-
 ![](../../images/Laptops/trackpad-md/ssdt-after.png)
 
-## Compiling the SSDT
+You will want to test the SSDT at this point by [compiling the SSDT!](/Manual/compile.md) and adding it to your config.plist. VoodooI2C should now be attached to the GPI0 device as shown at the top of the GPI0 section.
 
- With the SSDT done, you're now [ready to compile the SSDT!](/Manual/compile.md)
+## Enabling Trackpad
 
 ## Wrapping up