Documentation/devicetree/bindings/misc/olpc,xo1.75-ec.yaml

   1 # SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause
   2 # Copyright (C) 2019,2020 Lubomir Rintel <lkundrak@v3.sk>
   3 %YAML 1.2
   4 ---
   5 $id: http://devicetree.org/schemas/misc/olpc,xo1.75-ec.yaml#
   6 $schema: http://devicetree.org/meta-schemas/core.yaml#
   7
   8 title: OLPC XO-1.75 Embedded Controller bindings
   9
  10 description: |
  11   This binding describes the Embedded Controller acting as a SPI bus master
  12   on a OLPC XO-1.75 laptop computer.
  13
  14   The embedded controller requires the SPI controller driver to signal
  15   readiness to receive a transfer (that is, when TX FIFO contains the
  16   response data) by strobing the ACK pin with the ready signal. See the
  17   "ready-gpios" property of the SSP binding as documented in:
  18   <Documentation/devicetree/bindings/spi/marvell,mmp2-ssp.yaml>.
  19
  20 maintainers:
  21   - Lubomir Rintel <lkundrak@v3.sk>
  22
  23 properties:
  24   compatible:
  25     const: olpc,xo1.75-ec
  26
  27   cmd-gpios:
  28     description: GPIO uspecifier of the CMD pin
  29     maxItems: 1
  30
  31   spi-cpha: true
  32
  33 required:
  34   - compatible
  35   - cmd-gpios
  36
  37 additionalProperties: false
  38
  39 examples:
  40   - |
  41     #include <dt-bindings/gpio/gpio.h>
  42
  43     spi {
  44       spi-slave;
  45       #address-cells = <0>;
  46       #size-cells = <0>;
  47       ready-gpios = <&gpio 125 GPIO_ACTIVE_HIGH>;
  48
  49       slave {
  50         compatible = "olpc,xo1.75-ec";
  51         spi-cpha;
  52         cmd-gpios = <&gpio 155 GPIO_ACTIVE_HIGH>;
  53       };
  54     };
  55
  56 ...