diff options
| author | Lubomir Rintel <lkundrak@v3.sk> | 2019-05-13 09:56:32 +0200 |
|---|---|---|
| committer | Andy Shevchenko <andriy.shevchenko@linux.intel.com> | 2019-05-20 17:27:08 +0300 |
| commit | f22558d701755f2f9cfdbd4a0862a58ef5fb1dbb (patch) | |
| tree | 815e37018364570f16876d94ad316bd65cf083ff | |
| parent | d6423bd03031c020121da26c41a26bd5cc6d0da3 (diff) | |
dt-bindings: olpc,xo1.75-ec: Add OLPC XO-1.75 EC bindings
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>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
| -rw-r--r-- | Documentation/devicetree/bindings/misc/olpc,xo1.75-ec.txt | 23 |
1 files changed, 23 insertions, 0 deletions
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 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-gpios" property of the +SSP binding as documented in: +<Documentation/devicetree/bindings/spi/spi-pxa2xx.txt>. + +Example: + &ssp3 { + spi-slave; + ready-gpios = <&gpio 125 GPIO_ACTIVE_HIGH>; + + slave { + compatible = "olpc,xo1.75-ec"; + spi-cpha; + cmd-gpios = <&gpio 155 GPIO_ACTIVE_HIGH>; + }; + }; |