DT: hwspinlock: Add binding documentation for Qualcomm hwmutex

Add binding documentation for the Qualcomm Hardware Mutex.

Signed-off-by: Bjorn Andersson <bjorn.andersson@sonymobile.com>
Acked-by: Kumar Gala <galak@codeaurora.org>
Reviewed-by: Andy Gross <agross@codeaurora.org>
Reviewed-by: Jeffrey Hugo <jhugo@codeaurora.org>
Signed-off-by: Ohad Ben-Cohen <ohad@wizery.com>

1 files changed, 39 insertions, 0 deletions

diff --git a/Documentation/devicetree/bindings/hwlock/qcom-hwspinlock.txt b/Documentation/devicetree/bindings/hwlock/qcom-hwspinlock.txt
new file mode 100644
index 000000000000..4563f524556b
--- /dev/null
+++ b/Documentation/devicetree/bindings/hwlock/qcom-hwspinlock.txt
@@ -0,0 +1,39 @@
+Qualcomm Hardware Mutex Block:
+
+The hardware block provides mutexes utilized between different processors on
+the SoC as part of the communication protocol used by these processors.
+
+- compatible:
+        Usage: required
+        Value type: <string>
+        Definition: must be one of:
+                    "qcom,sfpb-mutex",
+                    "qcom,tcsr-mutex"
+
+- syscon:
+        Usage: required
+        Value type: <prop-encoded-array>
+        Definition: one cell containing:
+                    syscon phandle
+                    offset of the hwmutex block within the syscon
+                    stride of the hwmutex registers
+
+- #hwlock-cells:
+        Usage: required
+        Value type: <u32>
+        Definition: must be 1, the specified cell represent the lock id
+                    (hwlock standard property, see hwlock.txt)
+
+Example:
+
+        tcsr_mutex_block: syscon@fd484000 {
+                compatible = "syscon";
+                reg = <0xfd484000 0x2000>;
+        };
+
+        hwlock@fd484000 {
+                compatible = "qcom,tcsr-mutex";
+                syscon = <&tcsr_mutex_block 0 0x80>;
+
+                #hwlock-cells = <1>;
+        };