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- GPIO-based Sysinfo device
- This binding describes several GPIOs which specify a board revision. Each GPIO
- forms a digit in a ternary revision number. This revision is then mapped to a
- name using the revisions and names properties.
- Each GPIO may be floating, pulled-up, or pulled-down, mapping to digits 2, 1,
- and 0, respectively. The first GPIO forms the least-significant digit of the
- revision. For example, consider the property
- gpios = <&gpio 0>, <&gpio 1>, <&gpio 2>;
- If GPIO 0 is pulled-up, GPIO 1 is pulled-down, and GPIO 2 is floating, then the
- revision would be
- 0t201 = 2*9 + 0*3 + 1*3 = 19
- If instead GPIO 0 is floating, GPIO 1 is pulled-up, and GPIO 2 is pulled-down,
- then the revision would be
- 0t012 = 0*9 + 1*3 + 2*1 = 5
- Required properties:
- - compatible: should be "gpio-sysinfo".
- - gpios: should be a list of gpios forming the revision number,
- least-significant-digit first
- - revisions: a list of known revisions; any revisions not present will have the
- name "unknown"
- - names: the name of each revision in revisions
- Example:
- sysinfo {
- compatible = "gpio-sysinfo";
- gpios = <&gpio_a 15>, <&gpio_a 16>, <&gpio_a 17>;
- revisions = <19>, <5>;
- names = "rev_a", "foo";
- };
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