From 0f520ceee2b1fcb3ca943a621d7b5a569e6fca38 Mon Sep 17 00:00:00 2001
From: Daniel Barlow <dan@telent.net>
Date: Tue, 14 May 2024 18:07:33 +0100
Subject: [PATCH] create cdc-ncm module

---
 examples/l2tp.nix           |  2 +-
 modules/cdc-ncm/default.nix | 22 ++++++++++++++++++++++
 2 files changed, 23 insertions(+), 1 deletion(-)
 create mode 100644 modules/cdc-ncm/default.nix

diff --git a/examples/l2tp.nix b/examples/l2tp.nix
index 6aa983a..e755a89 100644
--- a/examples/l2tp.nix
+++ b/examples/l2tp.nix
@@ -20,7 +20,7 @@ in rec {
   };
 
   imports = [
-#    ../modules/wlan.nix
+    ../modules/cdc-ncm
     ../modules/network
     ../modules/vlan
     ../modules/ssh
diff --git a/modules/cdc-ncm/default.nix b/modules/cdc-ncm/default.nix
new file mode 100644
index 0000000..0e030f2
--- /dev/null
+++ b/modules/cdc-ncm/default.nix
@@ -0,0 +1,22 @@
+{ config, ... }:
+{
+  config = {
+    kernel.config = {
+      USB_NET_HUAWEI_CDC_NCM = "y";
+      USB_USBNET = "y";
+      USB_SERIAL = "y";
+      USB_SERIAL_OPTION = "y";
+    };
+
+    # an ncm ethernet adaptor does
+    # * usb modeswitch
+    # * AT commands
+    # and then behaves like a link.
+
+    # we could identify by vid:pid but that's a bit awkward
+    # if there's more than one present.  IMEI?
+
+    # https://stackoverflow.com/questions/5477882/how-to-i-detect-whether-a-tty-belonging-to-a-gsm-3g-modem-is-a-data-or-control-p
+  };
+}
+