60 lines
2.2 KiB
Plaintext
60 lines
2.2 KiB
Plaintext
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Broadcom FlexRM Ring Manager
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============================
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The Broadcom FlexRM ring manager provides a set of rings which can be
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used to submit work to offload engines. An SoC may have multiple FlexRM
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hardware blocks. There is one device tree entry per FlexRM block. The
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FlexRM driver will create a mailbox-controller instance for given FlexRM
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hardware block where each mailbox channel is a separate FlexRM ring.
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Required properties:
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--------------------
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- compatible: Should be "brcm,iproc-flexrm-mbox"
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- reg: Specifies base physical address and size of the FlexRM
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ring registers
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- msi-parent: Phandles (and potential Device IDs) to MSI controllers
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The FlexRM engine will send MSIs (instead of wired
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interrupts) to CPU. There is one MSI for each FlexRM ring.
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Refer devicetree/bindings/interrupt-controller/msi.txt
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- #mbox-cells: Specifies the number of cells needed to encode a mailbox
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channel. This should be 3.
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The 1st cell is the mailbox channel number.
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The 2nd cell contains MSI completion threshold. This is the
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number of completion messages for which FlexRM will inject
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one MSI interrupt to CPU.
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The 3nd cell contains MSI timer value representing time for
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which FlexRM will wait to accumulate N completion messages
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where N is the value specified by 2nd cell above. If FlexRM
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does not get required number of completion messages in time
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specified by this cell then it will inject one MSI interrupt
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to CPU provided atleast one completion message is available.
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Optional properties:
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--------------------
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- dma-coherent: Present if DMA operations made by the FlexRM engine (such
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as DMA descriptor access, access to buffers pointed by DMA
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descriptors and read/write pointer updates to DDR) are
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cache coherent with the CPU.
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Example:
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--------
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crypto_mbox: mbox@67000000 {
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compatible = "brcm,iproc-flexrm-mbox";
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reg = <0x67000000 0x200000>;
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msi-parent = <&gic_its 0x7f00>;
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#mbox-cells = <3>;
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};
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crypto@672c0000 {
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compatible = "brcm,spu2-v2-crypto";
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reg = <0x672c0000 0x1000>;
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mboxes = <&crypto_mbox 0 0x1 0xffff>,
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<&crypto_mbox 1 0x1 0xffff>,
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<&crypto_mbox 16 0x1 0xffff>,
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<&crypto_mbox 17 0x1 0xffff>,
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<&crypto_mbox 30 0x1 0xffff>,
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<&crypto_mbox 31 0x1 0xffff>;
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};
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