xref: /linux/Documentation/devicetree/bindings/misc/olpc,xo1.75-ec.yaml (revision 67f49869106f78882a8a09b736d4884be85aba18) 
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
8title: OLPC XO-1.75 Embedded Controller
9
10description: |
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
20maintainers:
21  - Lubomir Rintel <lkundrak@v3.sk>
22
23properties:
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
33required:
34  - compatible
35  - cmd-gpios
36
37additionalProperties: false
38
39examples:
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...
57