1 files changed, 42 insertions, 0 deletions

diff --git a/Documentation/powerpc/booting-without-of.txt b/Documentation/powerpc/booting-without-of.txt
index b68684d39f96..f6394b509430 100644
--- a/Documentation/powerpc/booting-without-of.txt
+++ b/Documentation/powerpc/booting-without-of.txt
@@ -2160,6 +2160,48 @@ platforms are moved over to use the flattened-device-tree model.
                 };
         };
 
+   x) I2C
+
+   The I2C controller is expressed as a bus under the CPM node.
+
+   Properties:
+   - compatible : "fsl,cpm1-i2c", "fsl,cpm2-i2c"
+   - reg : On CPM2 devices, the second resource doesn't specify the I2C
+     Parameter RAM itself, but the I2C_BASE field of the CPM2 Parameter RAM
+     (typically 0x8afc 0x2).
+   - #address-cells : Should be one. The cell is the i2c device address with
+     the r/w bit set to zero.
+   - #size-cells : Should be zero.
+   - clock-frequency : Can be used to set the i2c clock frequency. If
+     unspecified, a default frequency of 60kHz is being used.
+   The following two properties are deprecated. They are only used by legacy
+   i2c drivers to find the bus to probe:
+   - linux,i2c-index : Can be used to hard code an i2c bus number. By default,
+     the bus number is dynamically assigned by the i2c core.
+   - linux,i2c-class : Can be used to override the i2c class. The class is used
+     by legacy i2c device drivers to find a bus in a specific context like
+     system management, video or sound. By default, I2C_CLASS_HWMON (1) is
+     being used. The definition of the classes can be found in
+     include/i2c/i2c.h
+
+   Example, based on mpc823:
+
+        i2c@860 {
+                compatible = "fsl,mpc823-i2c",
+                             "fsl,cpm1-i2c";
+                reg = <0x860 0x20 0x3c80 0x30>;
+                interrupts = <16>;
+                interrupt-parent = <&CPM_PIC>;
+                fsl,cpm-command = <0x10>;
+                #address-cells = <1>;
+                #size-cells = <0>;
+
+                rtc@68 {
+                        compatible = "dallas,ds1307";
+                        reg = <0x68>;
+                };
+        };
+
    m) Chipselect/Local Bus
 
    Properties: