Adding upstream version 4.19.249.upstream/4.19.249upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 37 insertions, 0 deletions

diff --git a/Documentation/devicetree/bindings/i2c/i2c-opal.txt b/Documentation/devicetree/bindings/i2c/i2c-opal.txt
new file mode 100644
index 000000000..12bc61465
--- /dev/null
+++ b/Documentation/devicetree/bindings/i2c/i2c-opal.txt
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+Device-tree bindings for I2C OPAL driver
+----------------------------------------
+
+Most of the device node and properties layout is specific to the firmware and
+used by the firmware itself for configuring the port. From the linux
+perspective, the properties of use are "ibm,port-name" and "ibm,opal-id".
+
+Required properties:
+
+- reg: Port-id within a given master
+- compatible: must be "ibm,opal-i2c"
+- ibm,opal-id: Refers to a specific bus and used to identify it when calling
+	       the relevant OPAL functions.
+- bus-frequency: Operating frequency of the i2c bus (in HZ). Informational for
+		 linux, used by the FW though.
+
+Optional properties:
+- ibm,port-name: Firmware provides this name that uniquely identifies the i2c
+		 port.
+
+The node contains a number of other properties that are used by the FW itself
+and depend on the specific hardware implementation. The example below depicts
+a P8 on-chip bus.
+
+Example:
+
+i2c-bus@0 {
+	reg = <0x0>;
+	bus-frequency = <0x61a80>;
+	compatible = "ibm,power8-i2c-port", "ibm,opal-i2c";
+	ibm,opal-id = <0x1>;
+	ibm,port-name = "p8_00000000_e1p0";
+	#address-cells = <0x1>;
+	phandle = <0x10000006>;
+	#size-cells = <0x0>;
+	linux,phandle = <0x10000006>;
+};