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Diffstat (limited to 'roms/skiboot/doc/device-tree/ibm,opal/flash.rst')
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diff --git a/roms/skiboot/doc/device-tree/ibm,opal/flash.rst b/roms/skiboot/doc/device-tree/ibm,opal/flash.rst new file mode 100644 index 000000000..85e008cb8 --- /dev/null +++ b/roms/skiboot/doc/device-tree/ibm,opal/flash.rst @@ -0,0 +1,48 @@ +.. _device-tree/ibm,opal/flash: + +ibm,opal/flash device tree entries +================================== + +The flash@<n> nodes under ibm,opal describe flash devices that can be +accessed through the OPAL_FLASH_{READ,ERASE,WRITE} interface. + +These interfaces take an 'id' parameter, which corresponds to the ibm,opal-id +property of the node. + +The properties under a flash node are: + +- ``compatible = "ibm,opal-flash"`` + +``ibm,opal-id = <id>`` + provides the index used for the OPAL_FLASH_XXX calls to reference this + flash device + +``reg = <0 size>`` + the offset and size of the flash device + +``ibm,flash-block-size`` + the read/write/erase block size for the flash interface. Calls + to read/write/erase must be aligned to the block size. + +``#address-cells = <1>``, ``#size-cells = <1>`` + flash devices are currently 32-bit addressable + +If valid partitions are found on the flash device, then ``partition@<offset>`` +sub-nodes are added to the flash node. These match the Linux binding for +flash partitions; the reg parameter contains the offset and size of the +partition. + + +Example: + +.. code-block:: dts + + flash@0 { + reg = <0x0 0x4000000>; + compatible = "ibm,opal-flash"; + ibm,opal-id = <0x0>; + ibm,flash-block-size = <0x1000>; + #address-cells = <0x1>; + phandle = <0x100002bf>; + #size-cells = <0x1>; + }; |