imx6q-pads.el

;; Helpers for https://www.kernel.org/doc/Documentation/devicetree/bindings/pinctrl/fsl,imx6q-pinctrl.txt
(setq-local lexical-binding t)
(setq imx6q-pad-options '(
                          (PAD_CTL_HYS                     (1 . 16))
                          (PAD_CTL_PUS_100K_DOWN           (0 . 14))
                          (PAD_CTL_PUS_47K_UP              (1 . 14))
                          (PAD_CTL_PUS_100K_UP             (2 . 14))
                          (PAD_CTL_PUS_22K_UP              (3 . 14))
                          (PAD_CTL_PUE                     (1 . 13))
                          (PAD_CTL_PKE                     (1 . 12))
                          (PAD_CTL_ODE                     (1 . 11))
                          (PAD_CTL_SPEED_LOW               (1 . 6))
                          (PAD_CTL_SPEED_MED               (2 . 6))
                          (PAD_CTL_SPEED_HIGH              (3 . 6))
                          (PAD_CTL_DSE_DISABLE             (0 . 3))
                          (PAD_CTL_DSE_240ohm              (1 . 3))
                          (PAD_CTL_DSE_120ohm              (2 . 3))
                          (PAD_CTL_DSE_80ohm               (3 . 3))
                          (PAD_CTL_DSE_60ohm               (4 . 3))
                          (PAD_CTL_DSE_48ohm               (5 . 3))
                          (PAD_CTL_DSE_40ohm               (6 . 3))
                          (PAD_CTL_DSE_34ohm               (7 . 3))
                          (PAD_CTL_SRE_FAST                (1 . 0))
                          (PAD_CTL_SRE_SLOW                (0 . 0))
                          ))

(defun imx6q-get-option-bits (option)
  (let ((bits (car (car (cdr (assoc option imx6q-pad-options))))))
    (if bits
        bits
      (error "Can't find option %s" option))))

(defun imx6q-get-option-shift (option)
  (let ((shift (cdr (car (cdr (assoc option imx6q-pad-options))))))
    (if shift
        shift
      (error "Can't find option %s" option))))

(defun imx6q-get-option-value (option)
  (lsh (imx6q-get-option-bits option)
       (imx6q-get-option-shift option)))

(defun imx6q-get-mask (&rest options)
  (let ((opt-list nil))
    (dolist (opt options)
      (push (imx6q-get-option-value opt) opt-list))
    (format "0x%x" (apply 'logior opt-list))))

(defun imx6q-get-option-unshifted-value (opt)
  (let* ((opt-shift-negative (* -1 (imx6q-get-option-shift opt)))
         (opt-value (imx6q-get-option-value opt))
         (opt-mask  (lsh opt-value opt-shift-negative)))
    opt-mask))

(defun imx6q-bitmask (n)
  (let ((b 1))
    (dotimes (i (1- n))
      (setq b (lsh    b 1))
      (setq b (logior b 1)))
    b))


(setq imx6q-pads '(
                   (HYS 1 16)
                   (PUS 2 14)
                   (PUE 1 13)
                   (PKE 1 12)
                   (ODE 1 11)
                   (SPEED 2 6)
                   (DSE 3 3)
                   (SRE 1 0)))

(defun imx6q-pads-get-tuple (opt)
  (cdr (assoc opt imx6q-pads)))

(defun imx6q-pads-get-bits (opt)
  (car (imx6q-pads-get-tuple opt)))

(defun imx6q-pads-get-shift (opt)
  (car (cdr (imx6q-pads-get-tuple opt))))

(defun imx6q-pads-get-shift-negative (opt)
  (* -1 (imx6q-pads-get-shift opt)))

(defun imx6q-bitmask (n)
  (let ((b 1))
    (dotimes (i (1- n))
      (setq b (lsh    b 1))
      (setq b (logior b 1)))
    b))

(defun imx6q-pads-get-bitmask (opt)
  (imx6q-bitmask (imx6q-pads-get-bits opt)))

(defun imx6q-pads-get-option-value (opt mask)
  (logand (lsh mask (imx6q-pads-get-shift-negative opt)) (imx6q-pads-get-bitmask opt)))

(defun imx6q-get-mask-values (mask)
  (dolist (v imx6q-pads)
    (let ((key (nth 0 v)))
      (princ (format "%s: %s\n" key (imx6q-pads-get-option-value key mask))))))

(provide 'imx6q-pads)