Retrieves v4l2 camera controls from the device

This CL modifies a reference EVS HAL implementation to retrieve a list
of available camera controls from the device in run-time instead of
using a static parameter list from the configuration file.

Fix: 149311708
Test: Runs /vendor/bin/android.hardware.automotive.evs@1.1-sample
      and programs camera controls
Change-Id: I8c2b4650f12b7cf9e328980c5718d344efa76000

4 files changed, 33 insertions, 7 deletions

diff --git a/evs/sampleDriver/EvsV4lCamera.cpp b/evs/sampleDriver/EvsV4lCamera.cpp
index fdb893775..cd2a3a4ee 100644
--- a/evs/sampleDriver/EvsV4lCamera.cpp
+++ b/evs/sampleDriver/EvsV4lCamera.cpp
@@ -863,11 +863,7 @@ bool EvsV4lCamera::convertToV4l2CID(CameraParam id, uint32_t& v4l2cid) {
             return false;
     }
 
-    if (mCameraInfo != nullptr) {
-        return mCameraInfo->controls.find(id) != mCameraInfo->controls.end();
-    } else {
-        return false;
-    }
+    return mCameraControls.find(v4l2cid) != mCameraControls.end();
 }
 
 
@@ -939,6 +935,9 @@ sp<EvsV4lCamera> EvsV4lCamera::Create(const char *deviceName,
         }
     }
 
+    // List available camera parameters
+    evsCamera->mCameraControls = evsCamera->mVideo.enumerateCameraControls();
+
     // Please note that the buffer usage flag does not come from a given stream
     // configuration.
     evsCamera->mUsage  = GRALLOC_USAGE_HW_TEXTURE     |
diff --git a/evs/sampleDriver/EvsV4lCamera.h b/evs/sampleDriver/EvsV4lCamera.h
index c5b15a953..90cde5710 100644
--- a/evs/sampleDriver/EvsV4lCamera.h
+++ b/evs/sampleDriver/EvsV4lCamera.h
@@ -135,6 +135,8 @@ private:
     unsigned mFramesAllowed;                // How many buffers are we currently using
     unsigned mFramesInUse;                  // How many buffers are currently outstanding
 
+    std::set<uint32_t> mCameraControls;     // Available camera controls
+
     // Which format specific function we need to use to move camera imagery into our output buffers
     void(*mFillBufferFromVideo)(const BufferDesc& tgtBuff, uint8_t* tgt,
                                 void* imgData, unsigned imgStride);
diff --git a/evs/sampleDriver/VideoCapture.cpp b/evs/sampleDriver/VideoCapture.cpp
index 070e33fa0..9663bf694 100644
--- a/evs/sampleDriver/VideoCapture.cpp
+++ b/evs/sampleDriver/VideoCapture.cpp
@@ -323,3 +323,26 @@ int VideoCapture::getParameter(v4l2_control& control) {
 
     return status;
 }
+
+
+std::set<uint32_t> VideoCapture::enumerateCameraControls() {
+    // Retrieve available camera controls
+    struct v4l2_queryctrl ctrl = {
+        .id = V4L2_CTRL_FLAG_NEXT_CTRL
+    };
+
+    std::set<uint32_t> ctrlIDs;
+    while (0 == ioctl(mDeviceFd, VIDIOC_QUERYCTRL, &ctrl)) {
+        if (!(ctrl.flags & V4L2_CTRL_FLAG_DISABLED)) {
+            ctrlIDs.emplace(ctrl.id);
+        }
+
+        ctrl.id |= V4L2_CTRL_FLAG_NEXT_CTRL;
+    }
+
+    if (errno != EINVAL) {
+        PLOG(WARNING) << "Failed to run VIDIOC_QUERYCTRL";
+    }
+
+    return std::move(ctrlIDs);
+}
diff --git a/evs/sampleDriver/VideoCapture.h b/evs/sampleDriver/VideoCapture.h
index e205c36fd..42a5ef46c 100644
--- a/evs/sampleDriver/VideoCapture.h
+++ b/evs/sampleDriver/VideoCapture.h
@@ -17,10 +17,11 @@
 #define ANDROID_HARDWARE_AUTOMOTIVE_EVS_V1_1_VIDEOCAPTURE_H
 
 #include <atomic>
-#include <thread>
 #include <functional>
-#include <linux/videodev2.h>
+#include <set>
+#include <thread>
 
+#include <linux/videodev2.h>
 
 typedef v4l2_buffer imageBuffer;
 
@@ -49,6 +50,7 @@ public:
 
     int setParameter(struct v4l2_control& control);
     int getParameter(struct v4l2_control& control);
+    std::set<uint32_t> enumerateCameraControls();
 
 private:
     void collectFrames();