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
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+++ 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
