Add debug output for lights.

As an example and also to expose which lights are
registered easily. Note, this is all the information
that we can print given the libhardware lights interface.

Bug: 70846424
Test: lshal debug
Change-Id: I5f55e3e64149fc63a45ab9dab94d5fea27bb61da

1 files changed, 24 insertions, 0 deletions

diff --git a/light/2.0/default/Light.cpp b/light/2.0/default/Light.cpp
index cde1536633..5484d2db43 100644
--- a/light/2.0/default/Light.cpp
+++ b/light/2.0/default/Light.cpp
@@ -18,6 +18,8 @@
 
 #include <log/log.h>
 
+#include <stdio.h>
+
 #include "Light.h"
 
 namespace android {
@@ -107,6 +109,28 @@ const static std::map<Type, const char*> kLogicalLights = {
     {Type::WIFI,          LIGHT_ID_WIFI}
 };
 
+Return<void> Light::debug(const hidl_handle& handle, const hidl_vec<hidl_string>& /* options */) {
+    if (handle == nullptr || handle->numFds < 1) {
+        ALOGE("debug called with no handle\n");
+        return Void();
+    }
+
+    int fd = handle->data[0];
+    if (fd < 0) {
+        ALOGE("invalid FD: %d\n", handle->data[0]);
+        return Void();
+    }
+
+    dprintf(fd, "The following lights are registered: ");
+    for (auto const& pair : mLights) {
+        const Type type = pair.first;
+        dprintf(fd, "%s,", kLogicalLights.at(type));
+    }
+    dprintf(fd, ".\n");
+    fsync(fd);
+    return Void();
+}
+
 light_device_t* getLightDevice(const char* name) {
     light_device_t* lightDevice;
     const hw_module_t* hwModule = NULL;