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Diffstat (limited to 'Documentation/devicetree/bindings/powerpc/fsl/cpm_qe/cpm.txt')
-rw-r--r-- | Documentation/devicetree/bindings/powerpc/fsl/cpm_qe/cpm.txt | 67 |
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>; + }; + }; |