[PATCH 2/2] dt-bindings: Add DT bindings info for FlexRM mailbox driver

From: Anup Patel
Date: Thu Nov 24 2016 - 23:36:48 EST


This patch adds device tree bindings document for the FlexRM
mailbox driver.

Reviewed-by: Ray Jui <ray.jui@xxxxxxxxxxxx>
Reviewed-by: Scott Branden <scott.branden@xxxxxxxxxxxx>
Signed-off-by: Anup Patel <anup.patel@xxxxxxxxxxxx>
---
.../bindings/mailbox/brcm,flexrm-mbox.txt | 60 ++++++++++++++++++++++
1 file changed, 60 insertions(+)
create mode 100644 Documentation/devicetree/bindings/mailbox/brcm,flexrm-mbox.txt

diff --git a/Documentation/devicetree/bindings/mailbox/brcm,flexrm-mbox.txt b/Documentation/devicetree/bindings/mailbox/brcm,flexrm-mbox.txt
new file mode 100644
index 0000000..7969b1c
--- /dev/null
+++ b/Documentation/devicetree/bindings/mailbox/brcm,flexrm-mbox.txt
@@ -0,0 +1,60 @@
+Broadcom FlexRM Mailbox Driver
+===============================
+The Broadcom FlexRM ring manager provides a set of rings which can be
+used to submit work to offload engines. An SoC may have multiple FlexRM
+hardware blocks. There is one device tree entry per block. The FlexRM
+mailbox drivers creates a mailbox instance using FlexRM rings where
+each mailbox channel is a separate FlexRM ring.
+
+Required properties:
+--------------------
+- compatible: Should be "brcm,flexrm-mbox"
+- reg: Specifies base physical address and size of the FlexRM
+ ring registers
+- msi-parent: Phandles (and potential Device IDs) to MSI controllers
+ The FlexRM engine will send MSIs (instead of wired
+ interrupts) to CPU. There is one MSI for each FlexRM ring.
+ Refer devicetree/bindings/interrupt-controller/msi.txt
+- #mbox-cells: Specifies the number of cells needed to encode a mailbox
+ channel. This should be 3.
+
+ The 1st cell is the mailbox channel number.
+
+ The 2nd cell contains MSI completion threshold. This is the
+ number of completion messages for which FlexRM will inject
+ one MSI interrupt to CPU.
+
+ The 3nd cell contains MSI timer value representing time for
+ which FlexRM will wait to accumulate N completion messages
+ where N is the value specified by 2nd cell above. If FlexRM
+ does not get required number of completion messages in time
+ specified by this cell then it will inject one MSI interrupt
+ to CPU provided atleast one completion message is available.
+
+Optional properties:
+--------------------
+- dma-coherent: Present if DMA operations made by the FlexRM engine (such
+ as DMA descriptor access, access to buffers pointed by DMA
+ descriptors and read/write pointer updates to DDR) are
+ cache coherent with the CPU.
+
+Example:
+--------
+crypto_mbox: mbox@67000000 {
+ compatible = "brcm,flexrm-mbox";
+ reg = <0x67000000 0x200000>;
+ msi-parent = <&gic_its 0x7f00>;
+ #mbox-cells = <3>;
+};
+
+crypto_client {
+ ...
+ mboxes = <&crypto_mbox 0 0x1 0xffff>,
+ <&crypto_mbox 1 0x1 0xffff>,
+ <&crypto_mbox 16 0x1 0xffff>,
+ <&crypto_mbox 17 0x1 0xffff>,
+ <&crypto_mbox 30 0x1 0xffff>,
+ <&crypto_mbox 31 0x1 0xffff>;
+ };
+ ...
+};
--
2.7.4