import https://nixos.org/wiki/Acer_C720_Chromebook

Fixes https://github.com/NixOS/nixpkgs/issues/13169

acer/c720.nix

@@ -0,0 +1,10 @@
+{ lib, ... }:
+with lib;
+{
+  imports = singleton ../lib/kernerl-version.nix;
+
+  kernelAtleast = singleton
+    { version = "3.18";
+      msg = "Cypress APA touchpad supported added in Linux-3.17-rc1";
+    };
+}

acer/c720.wiki

@@ -0,0 +1,23 @@
+= Overview =
+* Processor: Intel Celeron 2955U @ 1.40GHz
+* Network controller: Qualcomm Atheros AR9462
+
+= Configuration =
+The C720 comes with a Cypress APA touchpad. Support for this touchpad was added in kernel 3.17-rc1.
+In order to get the touchpad working CONFIG_CHROME_PLATFORMS needs to be enabled.
+
+For example, for touchpad support with the 3.18 kernel, the following should be added to /etc/nixos/configuration.nix:
+
+  boot.kernelPackages = pkgs.linuxPackages_3_18;
+  nixpkgs.config.packageOverrides = pkgs:
+    { linux_3_18 = pkgs.linux_3_18.override {
+        extraConfig =
+          '''''''
+            CHROME_PLATFORMS y
+          ''''''';
+      };
+    };
+
+[[Category:Installation]]
+[[Category:Hardware]]
+[[Category:Laptops]]