From e78257c2014d260889280275d45adcc976e7ee6b Mon Sep 17 00:00:00 2001
From: Adrian Zankich <adrian@hybridgroup.com>
Date: Thu, 30 Oct 2014 16:22:25 -0700
Subject: [PATCH] Add docs

---
 sysfs/digital_pin.go      | 8 +++++---
 sysfs/digital_pin_test.go | 4 ----
 sysfs/doc.go              | 6 ++++++
 sysfs/i2c_device.go       | 2 +-
 4 files changed, 12 insertions(+), 8 deletions(-)
 create mode 100644 sysfs/doc.go

diff --git a/sysfs/digital_pin.go b/sysfs/digital_pin.go
index dd617361..87028467 100644
--- a/sysfs/digital_pin.go
+++ b/sysfs/digital_pin.go
@@ -21,7 +21,9 @@ type DigitalPin struct {
 	direction string
 }
 
-// NewDigitalPin returns a DigitalPin given the pin number and sysfs pin label
+// NewDigitalPin returns a DigitalPin given the pin number and an optional sysfs pin label.
+// If no label is supplied the default label will prepend "gpio" to the pin number,
+// eg. a pin number of 10 will have a label of "gpio10"
 func NewDigitalPin(pin int, v ...string) *DigitalPin {
 	d := &DigitalPin{pin: strconv.Itoa(pin)}
 	if len(v) > 0 {
@@ -38,14 +40,14 @@ func (d *DigitalPin) Direction() string {
 	return d.direction
 }
 
-// SetDirection sets the current direction for specified pin
+// SetDirection sets the current direction for the pin
 func (d *DigitalPin) SetDirection(dir string) error {
 	d.direction = dir
 	_, err := writeFile(fmt.Sprintf("%v/%v/direction", GPIOPATH, d.label), []byte(d.direction))
 	return err
 }
 
-// Write writes specified value to the pin
+// Write writes to the pin
 func (d *DigitalPin) Write(b int) error {
 	_, err := writeFile(fmt.Sprintf("%v/%v/value", GPIOPATH, d.label), []byte(strconv.Itoa(b)))
 	return err
diff --git a/sysfs/digital_pin_test.go b/sysfs/digital_pin_test.go
index b15ada8c..44d7018e 100644
--- a/sysfs/digital_pin_test.go
+++ b/sysfs/digital_pin_test.go
@@ -40,10 +40,6 @@ func TestDigitalPin(t *testing.T) {
 	gobot.Assert(t, lastPath, "/sys/class/gpio/gpio10/value")
 	gobot.Assert(t, string(lastData), "1")
 
-	pin.Write(1)
-	gobot.Assert(t, lastPath, "/sys/class/gpio/gpio10/value")
-	gobot.Assert(t, string(lastData), "1")
-
 	pin.SetDirection(IN)
 	gobot.Assert(t, lastPath, "/sys/class/gpio/gpio10/direction")
 	gobot.Assert(t, string(lastData), "in")
diff --git a/sysfs/doc.go b/sysfs/doc.go
new file mode 100644
index 00000000..b9da3266
--- /dev/null
+++ b/sysfs/doc.go
@@ -0,0 +1,6 @@
+/*
+Package sysfs provides generic access to linux gpio.
+
+It is intended to be used while implementing support for a single board linux computer
+*/
+package sysfs
diff --git a/sysfs/i2c_device.go b/sysfs/i2c_device.go
index b2614b73..05cc417d 100644
--- a/sysfs/i2c_device.go
+++ b/sysfs/i2c_device.go
@@ -10,7 +10,7 @@ import (
 
 const I2CSlave = 0x0703
 
-/// NewI2cDevice creates a new i2c device given a device location and address
+// NewI2cDevice creates a new io.ReadWriteCloser with the proper ioctrl given an i2c bus location and device address
 func NewI2cDevice(location string, address byte) (io.ReadWriteCloser, error) {
 	file, err := os.OpenFile(location, os.O_RDWR, os.ModeExclusive)