dt-bindings: Add spss_utils documentation

Adds documentation for spss_utils.

Change-Id: I6fed2234314a7edd4c5fb53f57910a40ce04a146

bindings/soc/qcom/qcom,spss-utils.txt

@@ -0,0 +1,37 @@
+Qualcomm Technologies, Inc. Secure Processor SubSystem Utilities (spss_utils)
+
+The Secure Processor SubSystem (SPSS) is a dedicated subsystem for security.
+It has its own CPU, memories, and cryptographic engine.
+It shall provide cryptographic services to other subsystems.
+The SPSS firmware is loaded by PIL driver.
+The communication with SPSS is done via spcom driver, using glink.
+
+The spss_utils driver selects the SPSS firmware file,
+according to a dedicated fuse and the platform HW version.
+
+Required properties:
+-compatible : should be "qcom,spss_utils"
+-qcom,spss-fuse1-addr: fuse1 register physical address
+-qcom,spss-fuse1-bit: fuse1 relevant bit
+-qcom,spss-fuse2-addr: fuse2 register physical address
+-qcom,spss-fuse2-bit: fuse2 relevant bit
+-qcom,spss-dev-firmware-name: dev firmware file name
+-qcom,spss-test-firmware-name: test firmware file name
+-qcom,spss-prod-firmware-name: production firmware file name
+-qcom,spss-debug-reg-addr: debug register physical address
+-qcom,spss-emul-type-reg-addr: soc emulation type register physical address
+
+Example:
+   qcom,spss_utils {
+      compatible = "qcom,spss-utils";
+
+      qcom,spss-fuse1-addr = <0x007841c4>;
+      qcom,spss-fuse1-bit = <27>;
+      qcom,spss-fuse2-addr = <0x007841c4>;
+      qcom,spss-fuse2-bit = <26>;
+      qcom,spss-dev-firmware-name  = "spss1d";  /* 8 chars max */
+      qcom,spss-test-firmware-name = "spss1t";  /* 8 chars max */
+      qcom,spss-prod-firmware-name = "spss1p";  /* 8 chars max */
+      qcom,spss-debug-reg-addr = <0x01886020>;
+      qcom,spss-emul-type-reg-addr = <0x01fc8004>;
+   };