diff --git a/development/misc.el b/development/misc.el
index c1320a0..20bc8c6 100644
--- a/development/misc.el
+++ b/development/misc.el
@@ -21,7 +21,19 @@
   (setq ebnf-mode-comment-char ?\;)       ; Use ; for comments
   (setq ebnf-mode-eop-char ?\.))         ; Use . for end of production
 
+;; Devicetree mode (ZMK keymap, .dts, .dtsi)
+(use-package! dts-mode
+  :mode ("\\.keymap\\'" "\\.dts\\'" "\\.dtsi\\'"))
+
 ;; Justfile mode (psibi/justl.el)
 (use-package! justl
   :config
   (map! :n "e" 'justl-exec-recipe))
+
+;; align-repeat: repeatedly align region by a given regexp/character
+;; From EmacsWiki: https://www.emacswiki.org/emacs/AlignCommands
+(defun align-repeat (start end regexp)
+  "Repeat alignment with respect to the given regular expression."
+  (interactive "r\nsAlign regexp: ")
+  (align-regexp start end
+                (concat "\\(\\s-*\\)" regexp) 1 1 t))