| Eugeniy Paltsev | 19b1a7f | 2018-06-08 17:58:24 +0300 | [diff] [blame] | 1 | GPIO via CREG (control registers) driver |
| 2 | |
| 3 | 31 9 7 5 0 < bit number |
| 4 | | | | | | |
| 5 | [ not used | gpio-1 | gpio-0 | <-shift-> ] < 32 bit register |
| 6 | ^ ^ |
| 7 | | | |
| 8 | write 0x2 == set output to "1" (activate) |
| 9 | write 0x3 == set output to "0" (deactivate) |
| 10 | |
| 11 | Required properties: |
| 12 | - compatible : "snps,creg-gpio" |
| 13 | - reg : Exactly one register range with length 0x4. |
| 14 | - #gpio-cells : Should be one - the pin number. |
| 15 | - gpio-controller : Marks the device node as a GPIO controller. |
| 16 | - gpio-count: Number of GPIO pins. |
| 17 | - gpio-bit-per-line: Number of bits per gpio line (see picture). |
| 18 | - gpio-first-shift: Shift (in bits) of the first GPIO field in register |
| 19 | (see picture). |
| 20 | - gpio-activate-val: Value should be set in corresponding field to set |
| 21 | output to "1" (see picture). Applied to all GPIO ports. |
| 22 | - gpio-deactivate-val: Value should be set in corresponding field to set |
| 23 | output to "0" (see picture). Applied to all GPIO ports. |
| 24 | |
| 25 | Optional properties: |
| 26 | - gpio-bank-name: name of bank (as default driver name is used is used) |
| 27 | - gpio-default-val: array of default output values (must me 0 or 1) |
| 28 | |
| 29 | Example (see picture): |
| 30 | |
| 31 | gpio: gpio@f00014b0 { |
| 32 | compatible = "snps,creg-gpio"; |
| 33 | reg = <0xf00014b0 0x4>; |
| 34 | gpio-controller; |
| 35 | #gpio-cells = <1>; |
| 36 | gpio-bank-name = "hsdk-spi-cs"; |
| 37 | gpio-count = <2>; |
| 38 | gpio-first-shift = <5>; |
| 39 | gpio-bit-per-line = <2>; |
| 40 | gpio-activate-val = <2>; |
| 41 | gpio-deactivate-val = <3>; |
| 42 | gpio-default-val = <1 1>; |
| 43 | }; |