ipmi: add an Aspeed KCS IPMI BMC driver

The KCS (Keyboard Controller Style) interface is used to perform in-band
IPMI communication between a server host and its BMC (BaseBoard Management
Controllers).

This driver exposes the KCS interface on ASpeed SOCs (AST2400 and AST2500)
as a character device. Such SOCs are commonly used as BMCs and this driver
implements the BMC side of the KCS interface.

OpenBMC-Staging-Count: 1
Signed-off-by: Haiyue Wang <haiyue.wang@linux.intel.com>
Signed-off-by: Corey Minyard <cminyard@mvista.com>
Signed-off-by: Joel Stanley <joel@jms.id.au>

1 files changed, 25 insertions, 0 deletions

diff --git a/Documentation/devicetree/bindings/ipmi/aspeed-kcs-bmc.txt b/Documentation/devicetree/bindings/ipmi/aspeed-kcs-bmc.txt
new file mode 100644
index 000000000000..d98a9bf45d6c
--- /dev/null
+++ b/Documentation/devicetree/bindings/ipmi/aspeed-kcs-bmc.txt
@@ -0,0 +1,25 @@
+* Aspeed KCS (Keyboard Controller Style) IPMI interface
+
+The Aspeed SOCs (AST2400 and AST2500) are commonly used as BMCs
+(Baseboard Management Controllers) and the KCS interface can be
+used to perform in-band IPMI communication with their host.
+
+Required properties:
+- compatible : should be one of
+    "aspeed,ast2400-kcs-bmc"
+    "aspeed,ast2500-kcs-bmc"
+- interrupts : interrupt generated by the controller
+- kcs_chan : The LPC channel number in the controller
+- kcs_addr : The host CPU IO map address
+
+
+Example:
+
+    kcs3: kcs3@0 {
+        compatible = "aspeed,ast2500-kcs-bmc";
+        reg = <0x0 0x80>;
+        interrupts = <8>;
+        kcs_chan = <3>;
+        kcs_addr = <0xCA2>;
+        status = "okay";
+    };