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From:   Lubomir Rintel <lkundrak@v3.sk>
To:     Mark Brown <broonie@kernel.org>,
        Geert Uytterhoeven <geert+renesas@glider.be>,
        Darren Hart <dvhart@infradead.org>,
        Andy Shevchenko <andy@infradead.org>
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        James Cameron <quozl@laptop.org>,
        Sebastian Reichel <sre@kernel.org>,
        Rob Herring <robh+dt@kernel.org>,
        Mark Rutland <mark.rutland@arm.com>,
        Eric Miao <eric.y.miao@gmail.com>,
        Haojian Zhuang <haojian.zhuang@gmail.com>,
        Daniel Mack <daniel@zonque.org>,
        Robert Jarzmik <robert.jarzmik@free.fr>,
        linux-spi@vger.kernel.org, devicetree@vger.kernel.org,
        linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
        platform-driver-x86@vger.kernel.org, devel@driverdev.osuosl.org,
        linux-pm@vger.kernel.org, Lubomir Rintel <lkundrak@v3.sk>
Subject: [PATCH v2 02/17] dt-bindings: olpc,xo1.75-ec: Add OLPC XO-1.75 EC bindings
Date:   Fri, 16 Nov 2018 17:23:48 +0100
Message-Id: <20181116162403.49854-3-lkundrak@v3.sk>
In-Reply-To: <20181116162403.49854-1-lkundrak@v3.sk>
References: <20181116162403.49854-1-lkundrak@v3.sk>
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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>
Acked-by: Pavel Machek <pavel@ucw.cz>

---
Changes since v1:
- s/cmd-gpio/cmd-gpios/
- s/ready-gpio/ready-gpios/ in the documentation paragraph
- Remove status =3D "okay" from the example

 .../bindings/misc/olpc,xo1.75-ec.txt          | 23 +++++++++++++++++++
 1 file changed, 23 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..8c4d649cdd8f
--- /dev/null
+++ b/Documentation/devicetree/bindings/misc/olpc,xo1.75-ec.txt
@@ -0,0 +1,23 @@
+OLPC XO-1.75 Embedded Controller
+
+Required properties:
+- compatible: Should be "olpc,xo1.75-ec".
+- cmd-gpios: gpio specifier of the CMD pin
+
+The embedded controller requires the SPI controller driver to signal rea=
diness
+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-gpios" proper=
ty of the
+SSP binding as documented in:
+<Documentation/devicetree/bindings/spi/spi-pxa2xx.txt>.
+
+Example:
+	&ssp3 {
+		spi-slave;
+		ready-gpios =3D <&gpio 125 GPIO_ACTIVE_HIGH>;
+
+		slave {
+			compatible =3D "olpc,xo1.75-ec";
+			spi-cpha;
+			cmd-gpios =3D <&gpio 155 GPIO_ACTIVE_HIGH>;
+		};
+	};
--=20
2.19.1