From bb39e64e2cdd43dcc3bde1d35548e1bcb114fef4 Mon Sep 17 00:00:00 2001
From: Matheus Sampaio <matheus.sampaio@virtus.ufcg.edu.br>
Date: Thu, 13 Jul 2017 10:10:57 -0300
Subject: [PATCH] feat: add readbytedata method

---
 lib/i2c.coffee |  6 ++++++
 src/i2c.cc     | 28 ++++++++++++++++++++++++++++
 2 files changed, 34 insertions(+)

diff --git a/lib/i2c.coffee b/lib/i2c.coffee
index cb0ddbb..b612fc6 100644
--- a/lib/i2c.coffee
+++ b/lib/i2c.coffee
@@ -78,6 +78,12 @@ class i2c extends EventEmitter
       tick ->
         callback err, data
 
+  readByteData: (position, callback) ->
+    @setAddress @address
+    wire.readByteData position, (err, data) ->
+      tick ->
+        callback err, data
+
   readBytes: (cmd, len, callback) ->
     @setAddress @address
     wire.readBlock cmd, len, null, (err, actualBuffer) ->
diff --git a/src/i2c.cc b/src/i2c.cc
index c7d4bee..cf51e78 100644
--- a/src/i2c.cc
+++ b/src/i2c.cc
@@ -148,6 +148,32 @@ void ReadByte(const Nan::FunctionCallbackInfo<v8::Value>& info) {
   info.GetReturnValue().Set(data);
 }
 
+void ReadByteData(const Nan::FunctionCallbackInfo<v8::Value>& info) {
+  Nan::HandleScope scope;
+
+  Local<Value> data;
+  Local<Value> err = Nan::New<Value>(Nan::Null());
+
+  int32_t position = info[0]->Int32Value();
+
+  int32_t res = i2c_smbus_read_byte_data(fd, position);
+
+  if (res == -1) {
+    err = Nan::Error(Nan::New("Cannot read device").ToLocalChecked());
+  } else {
+    data = Nan::New<Integer>(res);
+  }
+
+  if (info[1]->IsFunction()) {
+    const unsigned argc = 2;
+    Local<Function> callback = Local<Function>::Cast(info[1]);
+    Local<Value> argv[argc] = { err, data };
+    Nan::MakeCallback(Nan::GetCurrentContext()->Global(), callback, argc, argv);
+  }
+
+  info.GetReturnValue().Set(data);
+}
+
 void ReadBlock(const Nan::FunctionCallbackInfo<v8::Value>& info) {
   Nan::HandleScope scope;
 
@@ -287,6 +313,8 @@ void Init(Handle<Object> exports) {
                Nan::New<v8::FunctionTemplate>(Read)->GetFunction());
   exports->Set(Nan::New("readByte").ToLocalChecked(),
                Nan::New<v8::FunctionTemplate>(ReadByte)->GetFunction());
+  exports->Set(Nan::New("readByteData").ToLocalChecked(),
+               Nan::New<v8::FunctionTemplate>(ReadByteData)->GetFunction());
   exports->Set(Nan::New("readBlock").ToLocalChecked(),
                Nan::New<v8::FunctionTemplate>(ReadBlock)->GetFunction());