From b0c20e99a12f075a9a3289b05faf4fff8e0eb47f Mon Sep 17 00:00:00 2001
From: Steven Moreland <smoreland@google.com>
Date: Wed, 20 Dec 2017 14:50:53 -0800
Subject: [PATCH] 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
---
 light/2.0/default/Light.cpp | 24 ++++++++++++++++++++++++
 light/2.0/default/Light.h   |  5 +++--
 2 files changed, 27 insertions(+), 2 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;
diff --git a/light/2.0/default/Light.h b/light/2.0/default/Light.h
index 8987036f99..8851461de1 100644
--- a/light/2.0/default/Light.h
+++ b/light/2.0/default/Light.h
@@ -42,11 +42,12 @@ using ::android::sp;
 struct Light : public ILight {
     Light(std::map<Type, light_device_t*> &&lights);
 
-    // Methods from ::android::hardware::light::V2_0::ILight follow.
     Return<Status> setLight(Type type, const LightState& state)  override;
     Return<void> getSupportedTypes(getSupportedTypes_cb _hidl_cb)  override;
 
-private:
+    Return<void> debug(const hidl_handle& handle, const hidl_vec<hidl_string>& options) override;
+
+   private:
     std::map<Type, light_device_t*> mLights;
 };