From bd6381e513123178593dc8af13b02afeacd912ba Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Fr=C3=A9d=C3=A9ric=20Christ?= <frederic.christ@secunet.com>
Date: Sun, 26 Mar 2023 20:00:39 +0200
Subject: [PATCH 1/2] raspberry-pi/4: Add touch support for official 7"
 display.

---
 raspberry-pi/4/touch-ft5406.nix | 65 +++++++++++++++++++++++++++++++++
 1 file changed, 65 insertions(+)
 create mode 100644 raspberry-pi/4/touch-ft5406.nix

diff --git a/raspberry-pi/4/touch-ft5406.nix b/raspberry-pi/4/touch-ft5406.nix
new file mode 100644
index 0000000..12bb768
--- /dev/null
+++ b/raspberry-pi/4/touch-ft5406.nix
@@ -0,0 +1,65 @@
+{ config, lib, ... }:
+
+let
+  cfg = config.hardware.raspberry-pi."4".touch-ft5406;
+in
+{
+  options.hardware = {
+    raspberry-pi."4".touch-ft5406 = {
+      enable = lib.mkEnableOption ''
+        Enable the touch controller of the official Raspberry Pi touch diplay.
+
+        The overlay is taken from the official Raspberry Pi Linux fork, and
+        the `compatible` field is updated to match the target device tree.
+        https://github.com/raspberrypi/linux/blob/14b35093ca68bf2c81bbc90aace5007142b40b40/arch/arm/boot/dts/overlays/rpi-ft5406-overlay.dts
+
+        For more information about the touch display, please refer to:
+        https://www.raspberrypi.com/documentation/accessories/display.html
+      '';
+    };
+  };
+
+  config = lib.mkIf cfg.enable {
+    # Configure for modesetting in the device tree
+    hardware.deviceTree = {
+      overlays = [
+        # this *should* be equivalent to (which doesn't work):
+        # https://github.com/raspberrypi/linux/blob/rpi-5.10.y/arch/arm/boot/dts/overlays/dwc2-overlay.dts
+        # but actually it's obtained using
+        # dtc -I dtb -O dts ${config.hardware.deviceTree.kernelPackage}/dtbs/overlays/dwc2.dtbo
+        # (changes: modified top-level "compatible" field)
+        # which is slightly different and works
+        {
+          name = "rpi-ft5406-overlay";
+          dtsText = ''
+            /dts-v1/;
+            /plugin/;
+
+            / {
+            	compatible = "brcm,bcm2711";
+
+            	fragment@0 {
+            		target-path = "/soc/firmware";
+            		__overlay__ {
+            			ts: touchscreen {
+            				compatible = "raspberrypi,firmware-ts";
+            				touchscreen-size-x = <800>;
+            				touchscreen-size-y = <480>;
+            			};
+            		};
+            	};
+
+            	__overrides__ {
+            		touchscreen-size-x = <&ts>,"touchscreen-size-x:0";
+            		touchscreen-size-y = <&ts>,"touchscreen-size-y:0";
+            		touchscreen-inverted-x = <&ts>,"touchscreen-inverted-x?";
+            		touchscreen-inverted-y = <&ts>,"touchscreen-inverted-y?";
+            		touchscreen-swapped-x-y = <&ts>,"touchscreen-swapped-x-y?";
+                    };
+            };
+          '';
+        }
+      ];
+    };
+  };
+}

From 3023004e9903bc2f726da7c4a6724cf55f45bfff Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Fr=C3=A9d=C3=A9ric=20Christ?= <frederic.christ@secunet.com>
Date: Sun, 26 Mar 2023 20:11:16 +0200
Subject: [PATCH 2/2] raspberry-pi/4: Fix comments and indentation.

---
 raspberry-pi/4/touch-ft5406.nix | 9 +--------
 1 file changed, 1 insertion(+), 8 deletions(-)

diff --git a/raspberry-pi/4/touch-ft5406.nix b/raspberry-pi/4/touch-ft5406.nix
index 12bb768..5cc0a70 100644
--- a/raspberry-pi/4/touch-ft5406.nix
+++ b/raspberry-pi/4/touch-ft5406.nix
@@ -20,15 +20,8 @@ in
   };
 
   config = lib.mkIf cfg.enable {
-    # Configure for modesetting in the device tree
     hardware.deviceTree = {
       overlays = [
-        # this *should* be equivalent to (which doesn't work):
-        # https://github.com/raspberrypi/linux/blob/rpi-5.10.y/arch/arm/boot/dts/overlays/dwc2-overlay.dts
-        # but actually it's obtained using
-        # dtc -I dtb -O dts ${config.hardware.deviceTree.kernelPackage}/dtbs/overlays/dwc2.dtbo
-        # (changes: modified top-level "compatible" field)
-        # which is slightly different and works
         {
           name = "rpi-ft5406-overlay";
           dtsText = ''
@@ -55,7 +48,7 @@ in
             		touchscreen-inverted-x = <&ts>,"touchscreen-inverted-x?";
             		touchscreen-inverted-y = <&ts>,"touchscreen-inverted-y?";
             		touchscreen-swapped-x-y = <&ts>,"touchscreen-swapped-x-y?";
-                    };
+              };
             };
           '';
         }