Add information on setting up TD2 on Compute modules

Update instruction for setting up TD2 on Compute Modules

Typo

Add information on setting up TD2 on Compute modules

Updated from review comments

Updated after review comments

URL fixup

Hopefully last fixup from review comments

Author: JamesH65

documentation/asciidoc/accessories/display/display_intro.adoc

@@ -159,3 +159,7 @@ To specify these options, add them, separated by commas, to your `dtoverlay` lin
 ----
 dtoverlay=vc4-kms-dsi-7inch,sizex=400,invx,invy
 ----
+
+=== Installation on Compute Module based devices.
+
+All Raspberry Pi SBCs auto-detect the official Touch Displays as the circuitry connecting it to the DSI connector is fixed; this autodetection ensures the correct Device Tree entries are passed to the kernel. However, Compute Modules are intended for industrial applications where the integrator can use any and all GPIOs and interfaces for whatever purposes they require. Autodetection is therefore not feasible, and hence is disabled on Compute Module devices. This means that the Device Tree fragments required to set up the display need to be loaded via some other mechanism, which can be either with a dtoverlay entry in config.txt as described above, via a custom base DT file, or if present, a HAT EEPROM.

documentation/asciidoc/accessories/touch-display-2/about.adoc

@@ -127,3 +127,10 @@ To specify these options, add them, separated by commas, to your `dtoverlay` lin
 ----
 dtoverlay=vc4-kms-dsi-ili9881-7inch,sizex=400,invx,invy
 ----
+
+=== Installation and software setup on Compute Module based devices.
+
+All Raspberry Pi SBCs auto-detect the official Touch Displays as the circuitry connected to the DSI connector on the Raspberry Pi board is fixed; this autodetection ensures the correct Device Tree entries are passed to the kernel. However, Compute Modules are intended for industrial applications where the integrator can use any and all GPIOs and interfaces for whatever purposes they require. Autodetection is therefore not feasible, and hence is disabled on Compute Module devices. This means that the Device Tree fragments required to set up the display need to be loaded via some other mechanism, which can be either with a dtoverlay entry in config.txt, via a custom base DT file, or if present, a HAT EEPROM.
+
+Creating a custom base Device tree file is beyond the scope of this documentation, however, it is simple to add an appropriate device tree entry via `config.txt`. See this  xref:../computers/compute-module.adoc#attaching-the-touch-display-2-lcd-panel[page] for configuration details.
+

documentation/asciidoc/computers/compute-module/cmio-display.adoc

@@ -61,3 +61,21 @@ To entirely ignore the display when connected, add the following line to `/boot/
 ----
 ignore_lcd=1
 ----
+
+== Attaching the Touch Display 2 LCD panel
+
+Touch Display 2 is a 720x1280 7" LCD display designed specifically for Raspberry Pi devices (see https://www.raspberrypi.com/products/touch-display-2/). It connects in much the same way as the original touch display, but the software setup on Compute Modules is slightly different as it uses a different display driver. See xref:../accessories/touch-display-2.adoc[Touch Display 2] for connection details.
+
+Edit the /boot/firmware/config.txt file and add the following to enable Touch Display 2 on DSI1.
+
+[source,ini]
+----
+dtoverlay=vc4-kms-dsi-ili9881-7inch
+----
+
+To use DSI0 use the following:
+
+[source,ini]
+----
+dtoverlay=vc4-kms-dsi-ili9881-7inch,dsi0
+----