aboutsummaryrefslogtreecommitdiff
path: root/Documentation/devicetree/bindings/powerpc/fsl/cpm_qe/cpm.txt
diff options
context:
space:
mode:
Diffstat (limited to 'Documentation/devicetree/bindings/powerpc/fsl/cpm_qe/cpm.txt')
-rw-r--r--Documentation/devicetree/bindings/powerpc/fsl/cpm_qe/cpm.txt67
1 files changed, 67 insertions, 0 deletions
diff --git a/Documentation/devicetree/bindings/powerpc/fsl/cpm_qe/cpm.txt b/Documentation/devicetree/bindings/powerpc/fsl/cpm_qe/cpm.txt
new file mode 100644
index 00000000000..160c752484b
--- /dev/null
+++ b/Documentation/devicetree/bindings/powerpc/fsl/cpm_qe/cpm.txt
@@ -0,0 +1,67 @@
+* Freescale Communications Processor Module
+
+NOTE: This is an interim binding, and will likely change slightly,
+as more devices are supported. The QE bindings especially are
+incomplete.
+
+* Root CPM node
+
+Properties:
+- compatible : "fsl,cpm1", "fsl,cpm2", or "fsl,qe".
+- reg : A 48-byte region beginning with CPCR.
+
+Example:
+ cpm@119c0 {
+ #address-cells = <1>;
+ #size-cells = <1>;
+ #interrupt-cells = <2>;
+ compatible = "fsl,mpc8272-cpm", "fsl,cpm2";
+ reg = <119c0 30>;
+ }
+
+* Properties common to multiple CPM/QE devices
+
+- fsl,cpm-command : This value is ORed with the opcode and command flag
+ to specify the device on which a CPM command operates.
+
+- fsl,cpm-brg : Indicates which baud rate generator the device
+ is associated with. If absent, an unused BRG
+ should be dynamically allocated. If zero, the
+ device uses an external clock rather than a BRG.
+
+- reg : Unless otherwise specified, the first resource represents the
+ scc/fcc/ucc registers, and the second represents the device's
+ parameter RAM region (if it has one).
+
+* Multi-User RAM (MURAM)
+
+The multi-user/dual-ported RAM is expressed as a bus under the CPM node.
+
+Ranges must be set up subject to the following restrictions:
+
+- Children's reg nodes must be offsets from the start of all muram, even
+ if the user-data area does not begin at zero.
+- If multiple range entries are used, the difference between the parent
+ address and the child address must be the same in all, so that a single
+ mapping can cover them all while maintaining the ability to determine
+ CPM-side offsets with pointer subtraction. It is recommended that
+ multiple range entries not be used.
+- A child address of zero must be translatable, even if no reg resources
+ contain it.
+
+A child "data" node must exist, compatible with "fsl,cpm-muram-data", to
+indicate the portion of muram that is usable by the OS for arbitrary
+purposes. The data node may have an arbitrary number of reg resources,
+all of which contribute to the allocatable muram pool.
+
+Example, based on mpc8272:
+ muram@0 {
+ #address-cells = <1>;
+ #size-cells = <1>;
+ ranges = <0 0 10000>;
+
+ data@0 {
+ compatible = "fsl,cpm-muram-data";
+ reg = <0 2000 9800 800>;
+ };
+ };