From 188552e83fbac49718e0299daed84eaf7c94834d Mon Sep 17 00:00:00 2001
From: Brian Duddie <bduddie@google.com>
Date: Tue, 3 Jan 2017 09:38:24 -0800
Subject: [PATCH] contexthub: Expose CHRE version information

Add chrePlatformId and chreVersion fields to context hub metadata
returned by getHubs(). This information will be used to make
compatibility decisions at runtime. Also, add a brief description of
CHRE to the IContexthub documentation to help clarify the
relationship between the HAL and these concepts in the CHRE API.

Bug: 31402693
Test: compile test only, this only adds fields to HIDL structures
Change-Id: Iea2436ccc23b47c4cf06040bebe1c550fe58ccb7
---
 contexthub/1.0/IContexthub.hal |  7 +++++++
 contexthub/1.0/types.hal       | 16 ++++++++++++++++
 2 files changed, 23 insertions(+)

diff --git a/contexthub/1.0/IContexthub.hal b/contexthub/1.0/IContexthub.hal
index 8c792fd387..a9b8fdb7c2 100644
--- a/contexthub/1.0/IContexthub.hal
+++ b/contexthub/1.0/IContexthub.hal
@@ -18,6 +18,13 @@ package android.hardware.contexthub@1.0;
 
 import IContexthubCallback;
 
+/*
+ * The Context Hub HAL provides an interface to a separate low-power processing
+ * domain that has direct access to contextual information, such as sensors.
+ * Native applications that run within a context hub are known as nanoapps, and
+ * they execute within the Context Hub Runtime Environment (CHRE), which is
+ * standardized via the CHRE API, defined elsewhere.
+ */
 interface IContexthub {
     /*
      * Enumerate all available context hubs on the system.
diff --git a/contexthub/1.0/types.hal b/contexthub/1.0/types.hal
index c8ea623df2..02fd42fe40 100644
--- a/contexthub/1.0/types.hal
+++ b/contexthub/1.0/types.hal
@@ -108,6 +108,22 @@ struct ContextHub {
 
     uint32_t maxSupportedMsgLen;// This is the maximum size of the message that can
                                 // be sent to the hub in one chunk (in bytes)
+
+    // Machine-readable CHRE platform ID, returned to nanoapps in the CHRE API
+    // function call chreGetPlatformId(). The most significant 5 bytes of this
+    // value identify the vendor, while the remaining bytes are set by the
+    // vendor to uniquely identify each different CHRE implementation/hardware
+    // that the vendor supplies. This field pairs with the patch version part of
+    // chreVersion to fully specify the CHRE implementation version. See also
+    // the CHRE API header file chre/version.h.
+    uint64_t chrePlatformId;
+
+    // CHRE implementation version, returned to nanoApps in the CHRE API
+    // function call chreGetVersion(). This value consists of the implemented
+    // CHRE API version (major version in most significant byte, followed by
+    // minor version), and the platform-specific implementation patch version
+    // in the lower two bytes. See also the CHRE API header file chre/version.h.
+    uint32_t chreVersion;
 };
 
 struct ContextHubMsg {