altera_pio.txt 728 B

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  1. Altera GPIO controller bindings
  2. Required properties:
  3. - compatible:
  4. - "altr,pio-1.0"
  5. - reg: Physical base address and length of the controller's registers.
  6. Optional properties:
  7. - altr,gpio-bank-width: Width of the GPIO bank. This defines how many pins the
  8. GPIO device has. Ranges between 1-32. Optional and defaults to 32 if not
  9. specified.
  10. - gpio-bank-name: bank name attached to this device.
  11. Example:
  12. user_led_pio_8out: gpio@0x4cc0 {
  13. compatible = "altr,pio-1.0";
  14. reg = <0x00004cc0 0x00000010>;
  15. resetvalue = <255>;
  16. altr,gpio-bank-width = <8>;
  17. #gpio-cells = <2>;
  18. gpio-controller;
  19. gpio-bank-name = "led";
  20. };
  21. In this example, the gpio can be accessed as led[0..7] using gpio command of
  22. u-boot.
  23. ==> gpio clear led0