This commit adds a dt-bindings document of PECI adapter driver for Aspeed
AST24xx/25xx SoCs.

Signed-off-by: Jae Hyun Yoo <jae.hyun....@linux.intel.com>
---
 .../devicetree/bindings/peci/peci-aspeed.txt       | 73 ++++++++++++++++++++++
 1 file changed, 73 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/peci/peci-aspeed.txt

diff --git a/Documentation/devicetree/bindings/peci/peci-aspeed.txt 
b/Documentation/devicetree/bindings/peci/peci-aspeed.txt
new file mode 100644
index 000000000000..8a86f346d550
--- /dev/null
+++ b/Documentation/devicetree/bindings/peci/peci-aspeed.txt
@@ -0,0 +1,73 @@
+Device tree configuration for PECI buses on the AST24XX and AST25XX SoCs.
+
+Required properties:
+- compatible
+       "aspeed,ast2400-peci" or "aspeed,ast2500-peci"
+       - aspeed,ast2400-peci: Aspeed AST2400 family PECI controller
+       - aspeed,ast2500-peci: Aspeed AST2500 family PECI controller
+
+- reg
+       Should contain PECI registers location and length.
+
+- #address-cells
+       Should be <1>.
+
+- #size-cells
+       Should be <0>.
+
+- interrupts
+       Should contain PECI interrupt.
+
+- clocks
+       Should contain clock source for PECI hardware module. Should reference
+       clkin clock.
+
+- clock_frequency
+       Should contain the operation frequency of PECI hardware module.
+       187500 ~ 24000000
+
+Optional properties:
+- msg-timing-nego
+       Message timing negotiation period. This value will determine the period
+       of message timing negotiation to be issued by PECI controller. The unit
+       of the programmed value is four times of PECI clock period.
+       0 ~ 255 (default: 1)
+
+- addr-timing-nego
+       Address timing negotiation period. This value will determine the period
+       of address timing negotiation to be issued by PECI controller. The unit
+       of the programmed value is four times of PECI clock period.
+       0 ~ 255 (default: 1)
+
+- rd-sampling-point
+       Read sampling point selection. The whole period of a bit time will be
+       divided into 16 time frames. This value will determine which time frame
+       this controller will sample PECI signal for data read back. Usually in
+       the middle of a bit time is the best.
+       0 ~ 15 (default: 8)
+
+- cmd_timeout_ms
+       Command timeout in units of ms.
+       1 ~ 60000 (default: 1000)
+
+Example:
+       peci: peci@1e78b000 {
+               compatible = "simple-bus";
+               #address-cells = <1>;
+               #size-cells = <1>;
+               ranges = <0x0 0x1e78b000 0x60>;
+
+               peci0: peci-bus@0 {
+                       compatible = "aspeed,ast2500-peci";
+                       reg = <0x0 0x60>;
+                       #address-cells = <1>;
+                       #size-cells = <0>;
+                       interrupts = <15>;
+                       clocks = <&clk_clkin>;
+                       clock-frequency = <24000000>;
+                       msg-timing-nego = <1>;
+                       addr-timing-nego = <1>;
+                       rd-sampling-point = <8>;
+                       cmd-timeout-ms = <1000>;
+               };
+       };
\ No newline at end of file
-- 
2.16.1

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