[PATCH 03/15] dt-bindings: olpc,xo1.75-ec: Add OLPC XO-1.75 EC bindings
flat view
STALE2884d
SUPERSEDED
From: Lubomir Rintel <lkundrak@v3.sk>
Date: 2018-10-10 17:23:32
Also in:
linux-arm-kernel, linux-devicetree, linux-spi, lkml, platform-driver-x86
Subsystem:
open firmware and flattened device tree bindings, the rest · Maintainers:
Rob Herring, Krzysztof Kozlowski, Conor Dooley, Linus Torvalds
Revision v1 of 7 in this series.
Revisions (7)
The OLPC XO-1.75 Embedded Controller is a SPI master that uses extra signals for handshaking. It needs to know when is the slave (Linux) side's TX FIFO ready for transfer (the ready-gpio signal on the SPI controller node) and when does it wish to respond with a command (the cmd-gpio property). Signed-off-by: Lubomir Rintel <lkundrak@v3.sk> --- .../bindings/misc/olpc,xo1.75-ec.txt | 24 +++++++++++++++++++ 1 file changed, 24 insertions(+) create mode 100644 Documentation/devicetree/bindings/misc/olpc,xo1.75-ec.txt
diff --git a/Documentation/devicetree/bindings/misc/olpc,xo1.75-ec.txt b/Documentation/devicetree/bindings/misc/olpc,xo1.75-ec.txt
new file mode 100644
index 000000000000..14385fee65d2
--- /dev/null
+++ b/Documentation/devicetree/bindings/misc/olpc,xo1.75-ec.txt@@ -0,0 +1,24 @@ +OLPC XO-1.75 Embedded Controller + +Required properties: +- compatible: Should be "olpc,xo1.75-ec". +- cmd-gpio: gpio specifier of the CMD pin + +The embedded controller requires the SPI controller driver to signal readiness +to receive a transfer (that is, when TX FIFO contains the response data) by +strobing the ACK pin with the ready signal. See the "ready-gpio" property of the +SSP binding as documented in: +<Documentation/devicetree/bindings/spi/spi-pxa2xx.txt>. + +Example: + &ssp3 { + spi-slave; + status = "okay"; + ready-gpio = <&gpio 125 GPIO_ACTIVE_HIGH>; + + slave { + compatible = "olpc,xo1.75-ec"; + spi-cpha; + cmd-gpio = <&gpio 155 GPIO_ACTIVE_HIGH>; + }; + };
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2.19.0