org-edit-src-code is an interactive compiled Lisp function in `
(org-edit-src-code &optional CONTEXT CODE EDIT-BUFFER-NAME)
Edit the source CODE block at point.
The code is copied to a separate buffer and the appropriate mode
is turned on. When done, exit with M-x org-edit-src-exit. This will
remove the original code in the Org buffer, and replace it with the
edited version. An optional argument CONTEXT is used by M-x org-edit-src-save
when calling this function. See `org-src-window-setup' to configure
the display of windows containing the Org buffer and the code buffer.