Disable yas-expand if the cursor is in orgmode's source block

my:yas-expand.el

(defun my:yas-expand (&optional field)
  "Disable `yas-expand' in src-block."
  (interactive)
  (if (and (equal major-mode 'org-mode)
           (org-in-src-block-p t)
           (not (and (fboundp 'org-src-edit-buffer-p)
                     (org-src-edit-buffer-p))))
      (org-cycle)
    (yas-expand field)))
(define-key yas-minor-mode-map (kbd "<tab>") 'my:yas-expand)))