dt-bindings: mailbox: Document Hi6220 mailbox driver

Document the new compatible for Hisilicon Hi6220 mailbox driver.

Signed-off-by: Leo Yan <leo.yan@linaro.org>

1 files changed, 57 insertions, 0 deletions

diff --git a/Documentation/devicetree/bindings/mailbox/hisilicon,hi6220-mailbox.txt b/Documentation/devicetree/bindings/mailbox/hisilicon,hi6220-mailbox.txt
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+Hisilicon Hi6220 Mailbox Driver
+===============================
+
+Hisilicon Hi6220 mailbox supports up to 32 channels. Each channel
+is unidirectional with a maximum message size of 8 words. I/O is
+performed using register access (there is no DMA) and the cell
+raises an interrupt when messages are received.
+
+Mailbox Device Node:
+====================
+
+Required properties:
+--------------------
+- compatible:		Shall be "hisilicon,hi6220-mbox"
+- reg:			Contains the mailbox register address range (base
+			address and length); the first item is for IPC
+			registers, the second item is shared buffer for
+			slots.
+- #mbox-cells		Common mailbox binding property to identify the number
+			of cells required for the mailbox specifier. Should be 1.
+- interrupts:		Contains the interrupt information for the mailbox
+			device. The format is dependent on which interrupt
+			controller the SoCs use.
+
+Example:
+--------
+
+	mailbox: mailbox@F7510000 {
+		#mbox-cells = <1>;
+		compatible = "hisilicon,hi6220-mbox";
+		reg = <0x0 0xF7510000 0x0 0x1000>, /* IPC_S */
+		      <0x0 0x06DFF800 0x0 0x0800>; /* Mailbox */
+		interrupt-parent = <&gic>;
+		interrupts = <0 94 4>;
+	};
+
+
+Mailbox client
+===============
+
+"mboxes" and the optional "mbox-names" (please see
+Documentation/devicetree/bindings/mailbox/mailbox.txt for details). Each value
+of the mboxes property should contain a phandle to the mailbox controller
+device node and second argument is the channel index. It must be 0 (hardware
+support only one channel). The equivalent "mbox-names" property value can be
+used to give a name to the communication channel to be used by the client user.
+
+Example:
+--------
+
+	stub_clock: stub_clock {
+		compatible = "hisilicon,hi6220-stub-clk";
+		hisilicon,hi6220-clk-sram = <&sram>;
+		#clock-cells = <1>;
+		mbox-names = "mbox-tx";
+		mboxes = <&mailbox 1>;
+	};