linux/Documentation/devicetree/bindings/i2c/i2c-opal.txt
Neelesh Gupta 470834508f i2c: Driver to expose PowerNV platform i2c busses
The patch exposes the available i2c busses on the PowerNV platform
to the kernel and implements the bus driver to support i2c and
smbus commands.
The driver uses the platform device infrastructure to probe the busses
on the platform and registers them with the i2c driver framework.

Signed-off-by: Neelesh Gupta <neelegup@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Acked-by: Wolfram Sang <wsa@the-dreams.de> (I2C part, excluding the bindings)
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2014-12-14 12:44:46 +11:00

38 lines
1.2 KiB
Plaintext

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>;
};