dt-bindings: gnss: add sirfstar binding

Add binding for SiRFstar-based GNSS receivers.

Note that while four compatible-strings are initially added representing
devices which differ in which I/O interfaces they support, they
otherwise essentially share the same feature set.

Pin and supply names vary slightly, as do some recommended timings.

Note that the wakeup gpio is not intended to be used as a wakeup source,
but rather to detect the current power state of the device (active or
hibernate).

Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 45 insertions, 0 deletions

diff --git a/Documentation/devicetree/bindings/gnss/sirfstar.txt b/Documentation/devicetree/bindings/gnss/sirfstar.txt
new file mode 100644
index 000000000000..648d183cdb77
--- /dev/null
+++ b/Documentation/devicetree/bindings/gnss/sirfstar.txt
@@ -0,0 +1,45 @@
+SiRFstar-based GNSS Receiver DT binding
+
+SiRFstar chipsets are used in GNSS-receiver modules produced by several
+vendors and can use UART, SPI or I2C interfaces.
+
+Please see Documentation/devicetree/bindings/gnss/gnss.txt for generic
+properties.
+
+Required properties:
+
+- compatible	: Must be one of
+
+			"fastrax,uc430"
+			"linx,r4"
+			"wi2wi,w2sg0008i"
+			"wi2wi,w2sg0084i"
+
+- vcc-supply	: Main voltage regulator (pin name: 3V3_IN, VCC, VDD)
+
+Required properties (I2C):
+- reg		: I2C slave address
+
+Required properties (SPI):
+- reg		: SPI chip select address
+
+Optional properties:
+
+- sirf,onoff-gpios	: GPIO used to power on and off device (pin name: ON_OFF)
+- sirf,wakeup-gpios	: GPIO used to determine device power state
+			  (pin name: RFPWRUP, WAKEUP)
+- timepulse-gpios	: Time pulse GPIO (pin name: 1PPS, TM)
+
+Example:
+
+serial@1234 {
+	compatible = "ns16550a";
+
+	gnss {
+		compatible = "wi2wi,w2sg0084i";
+
+		vcc-supply = <&gnss_reg>;
+		sirf,onoff-gpios = <&gpio0 16 GPIO_ACTIVE_HIGH>;
+		sirf,wakeup-gpios = <&gpio0 17 GPIO_ACTIVE_HIGH>;
+	};
+};