GPIO via CREG (control registers) driver
31 9 7 5 0 < bit number
| | | | |
[ not used | gpio-1 | gpio-0 | <-shift-> ] < 32 bit register
^ ^
| |
write 0x2 == set output to "1" (activate)
write 0x3 == set output to "0" (deactivate)
Required properties:
- compatible : "snps,creg-gpio"
- reg : Exactly one register range with length 0x4.
- #gpio-cells : Should be one - the pin number.
- gpio-controller : Marks the device node as a GPIO controller.
- gpio-count: Number of GPIO pins.
- gpio-bit-per-line: Number of bits per gpio line (see picture).
- gpio-first-shift: Shift (in bits) of the first GPIO field in register
(see picture).
- gpio-activate-val: Value should be set in corresponding field to set
output to "1" (see picture). Applied to all GPIO ports.
- gpio-deactivate-val: Value should be set in corresponding field to set
output to "0" (see picture). Applied to all GPIO ports.
Optional properties:
- gpio-bank-name: name of bank (as default driver name is used is used)
- gpio-default-val: array of default output values (must me 0 or 1)
Example (see picture):
gpio: gpio@f00014b0 {
compatible = "snps,creg-gpio";
reg = <0xf00014b0 0x4>;
gpio-controller;
#gpio-cells = <1>;
gpio-bank-name = "hsdk-spi-cs";
gpio-count = <2>;
gpio-first-shift = <5>;
gpio-bit-per-line = <2>;
gpio-activate-val = <2>;
gpio-deactivate-val = <3>;
gpio-default-val = <1 1>;
};