From 0a315c253ca170a6e7e181ec13489d256f811bd0 Mon Sep 17 00:00:00 2001
From: andig <cpuidle@gmx.de>
Date: Sun, 23 Sep 2018 11:37:26 +0200
Subject: [PATCH] Provide generic logging interface

---
 client.go    | 5 +++++
 serial.go    | 3 +--
 tcpclient.go | 3 +--
 3 files changed, 7 insertions(+), 4 deletions(-)

diff --git a/client.go b/client.go
index ac3ee2e..4b69dc2 100644
--- a/client.go
+++ b/client.go
@@ -9,6 +9,11 @@ import (
 	"fmt"
 )
 
+// logger is the interface to the required logging functions
+type logger interface {
+	Printf(format string, v ...interface{})
+}
+
 // ClientHandler is the interface that groups the Packager and Transporter methods.
 type ClientHandler interface {
 	Packager
diff --git a/serial.go b/serial.go
index 7d14c67..01e2b9a 100644
--- a/serial.go
+++ b/serial.go
@@ -6,7 +6,6 @@ package modbus
 
 import (
 	"io"
-	"log"
 	"sync"
 	"time"
 
@@ -24,7 +23,7 @@ type serialPort struct {
 	// Serial port configuration.
 	serial.Config
 
-	Logger      *log.Logger
+	Logger      logger
 	IdleTimeout time.Duration
 
 	mu sync.Mutex
diff --git a/tcpclient.go b/tcpclient.go
index 4e53c73..5dcc01b 100644
--- a/tcpclient.go
+++ b/tcpclient.go
@@ -8,7 +8,6 @@ import (
 	"encoding/binary"
 	"fmt"
 	"io"
-	"log"
 	"net"
 	"sync"
 	"sync/atomic"
@@ -135,7 +134,7 @@ type tcpTransporter struct {
 	// Idle timeout to close the connection
 	IdleTimeout time.Duration
 	// Transmission logger
-	Logger *log.Logger
+	Logger logger
 
 	// TCP connection
 	mu           sync.Mutex