diff options
Diffstat (limited to 'Documentation')
| -rw-r--r-- | Documentation/powerpc/booting-without-of.txt | 40 |
1 files changed, 36 insertions, 4 deletions
diff --git a/Documentation/powerpc/booting-without-of.txt b/Documentation/powerpc/booting-without-of.txt index c36dcd2fbdc..ce5d67f5cb5 100644 --- a/Documentation/powerpc/booting-without-of.txt +++ b/Documentation/powerpc/booting-without-of.txt @@ -1861,9 +1861,7 @@ platforms are moved over to use the flattened-device-tree model. Properties: - compatible : "fsl,cpm1", "fsl,cpm2", or "fsl,qe". - - reg : The first resource is a 48-byte region beginning with - CPCR. The second is the available general-purpose - DPRAM. + - reg : A 48-byte region beginning with CPCR. Example: cpm@119c0 { @@ -1871,7 +1869,7 @@ platforms are moved over to use the flattened-device-tree model. #size-cells = <1>; #interrupt-cells = <2>; compatible = "fsl,mpc8272-cpm", "fsl,cpm2"; - reg = <119c0 30 0 2000>; + reg = <119c0 30>; } ii) Properties common to mulitple CPM/QE devices @@ -2017,6 +2015,40 @@ platforms are moved over to use the flattened-device-tree model. fsl,cpm-command = <2e600000>; }; + viii) 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>; + }; + }; + m) Chipselect/Local Bus Properties: |