0001 # SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause
0002 # Copyright (C) 2019,2020 Lubomir Rintel <lkundrak@v3.sk>
0003 %YAML 1.2
0004 ---
0005 $id: http://devicetree.org/schemas/misc/olpc,xo1.75-ec.yaml#
0006 $schema: http://devicetree.org/meta-schemas/core.yaml#
0007
0008 title: OLPC XO-1.75 Embedded Controller bindings
0009
0010 description: |
0011 This binding describes the Embedded Controller acting as a SPI bus master
0012 on a OLPC XO-1.75 laptop computer.
0013
0014 The embedded controller requires the SPI controller driver to signal
0015 readiness to receive a transfer (that is, when TX FIFO contains the
0016 response data) by strobing the ACK pin with the ready signal. See the
0017 "ready-gpios" property of the SSP binding as documented in:
0018 <Documentation/devicetree/bindings/spi/marvell,mmp2-ssp.yaml>.
0019
0020 maintainers:
0021 - Lubomir Rintel <lkundrak@v3.sk>
0022
0023 properties:
0024 compatible:
0025 const: olpc,xo1.75-ec
0026
0027 cmd-gpios:
0028 description: GPIO uspecifier of the CMD pin
0029 maxItems: 1
0030
0031 spi-cpha: true
0032
0033 required:
0034 - compatible
0035 - cmd-gpios
0036
0037 additionalProperties: false
0038
0039 examples:
0040 - |
0041 #include <dt-bindings/gpio/gpio.h>
0042
0043 spi {
0044 spi-slave;
0045 #address-cells = <0>;
0046 #size-cells = <0>;
0047 ready-gpios = <&gpio 125 GPIO_ACTIVE_HIGH>;
0048
0049 slave {
0050 compatible = "olpc,xo1.75-ec";
0051 spi-cpha;
0052 cmd-gpios = <&gpio 155 GPIO_ACTIVE_HIGH>;
0053 };
0054 };
0055
0056 ...
