From mboxrd@z Thu Jan 1 00:00:00 1970 From: pavel@ucw.cz (Pavel Machek) Date: Sun, 4 Nov 2018 13:26:36 +0100 Subject: [PATCH 03/15] dt-bindings: olpc,xo1.75-ec: Add OLPC XO-1.75 EC bindings In-Reply-To: <20181010172300.317643-4-lkundrak@v3.sk> References: <20181010172300.317643-1-lkundrak@v3.sk> <20181010172300.317643-4-lkundrak@v3.sk> Message-ID: <20181104122636.GX23864@amd> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Wed 2018-10-10 19:22:48, Lubomir Rintel wrote: > 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 Acked-by: Pavel Machek > --- > .../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: > +. > + > +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>; > + }; > + }; -- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html -------------- next part -------------- A non-text attachment was scrubbed... Name: signature.asc Type: application/pgp-signature Size: 181 bytes Desc: Digital signature URL: