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