[v5,01/10] dt-bindings: olpc,xo1.75-ec: Add OLPC XO-1.75 EC bindings
diff mbox series

Message ID 20190110175845.1203986-2-lkundrak@v3.sk
State Changes Requested, archived
Delegated to: Darren Hart
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Series
  • Add support for OLPC XO 1.75 Embedded Controller
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Commit Message

Lubomir Rintel Jan. 10, 2019, 5:58 p.m. UTC
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 = "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

Comments

Rob Herring Jan. 11, 2019, 2:36 p.m. UTC | #1
On Thu, 10 Jan 2019 18:58:36 +0100, 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 <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 = "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
> 

Please add Acked-by/Reviewed-by tags when posting new versions. However,
there's no need to repost patches *only* to add the tags. The upstream
maintainer will do that for acks received on the version they apply.

If a tag was not added on purpose, please state why and what changed.
Darren Hart Feb. 21, 2019, 1:21 a.m. UTC | #2
On Fri, Jan 11, 2019 at 08:36:35AM -0600, Rob Herring wrote:
> On Thu, 10 Jan 2019 18:58:36 +0100, 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 <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 = "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
> > 
> 
> Please add Acked-by/Reviewed-by tags when posting new versions. However,
> there's no need to repost patches *only* to add the tags. The upstream
> maintainer will do that for acks received on the version they apply.
> 
> If a tag was not added on purpose, please state why and what changed.

Rob, I saw you ack this patch in an earlier version. Based on your comment here,
is that ack still valid?

Patch
diff mbox series

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>;
+		};
+	};