From 188fd8382de1ecf937e5776849dcd7db1fde442c Mon Sep 17 00:00:00 2001
From: Sebastian Zagrodzki <sebek@zagrodzki.net>
Date: Sun, 9 Apr 2017 20:27:37 +0200
Subject: [PATCH] more comments

---
 usb/transfer.go | 2 +-
 usb/usb.go      | 4 ++++
 2 files changed, 5 insertions(+), 1 deletion(-)

diff --git a/usb/transfer.go b/usb/transfer.go
index 5631ca9..aabc636 100644
--- a/usb/transfer.go
+++ b/usb/transfer.go
@@ -44,7 +44,7 @@ func (t *usbTransfer) submit() error {
 	t.mu.Lock()
 	defer t.mu.Unlock()
 	if t.submitted {
-		return errors.New("transfer was already submitted and is not finished yet.")
+		return errors.New("transfer was already submitted and is not finished yet")
 	}
 	t.done = make(chan struct{})
 	if err := libusb.submit(t.xfer, t.done); err != nil {
diff --git a/usb/usb.go b/usb/usb.go
index 12924f3..0e767da 100644
--- a/usb/usb.go
+++ b/usb/usb.go
@@ -16,15 +16,18 @@
 // Package usb provides a wrapper around libusb-1.0.
 package usb
 
+// Context is the libusb context instance.
 type Context struct {
 	ctx  *libusbContext
 	done chan struct{}
 }
 
+// Debug changes the libusb debug level.
 func (c *Context) Debug(level int) {
 	libusb.setDebug(c.ctx, level)
 }
 
+// NewContext initializes libusb and returns a new context instance.
 func NewContext() *Context {
 	c, err := libusb.init()
 	if err != nil {
@@ -97,6 +100,7 @@ func (c *Context) OpenDeviceWithVidPid(vid, pid int) (*Device, error) {
 	return devs[0], nil
 }
 
+// Close releases the libusb context.
 func (c *Context) Close() error {
 	c.done <- struct{}{}
 	if c.ctx != nil {