forked from zlowred/embd
-
Notifications
You must be signed in to change notification settings - Fork 0
/
led.go
113 lines (87 loc) · 1.61 KB
/
led.go
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
// LED control support.
package generic
import (
"fmt"
"io/ioutil"
"os"
"strings"
"github.com/zlowred/embd"
)
type led struct {
id string
brightness *os.File
initialized bool
}
func NewLED(id string) embd.LED {
return &led{id: id}
}
func (l *led) init() error {
if l.initialized {
return nil
}
var err error
if l.brightness, err = l.brightnessFile(); err != nil {
return err
}
l.initialized = true
return nil
}
func (l *led) brightnessFilePath() string {
return fmt.Sprintf("/sys/class/leds/%v/brightness", l.id)
}
func (l *led) openFile(path string) (*os.File, error) {
return os.OpenFile(path, os.O_RDWR, os.ModeExclusive)
}
func (l *led) brightnessFile() (*os.File, error) {
return l.openFile(l.brightnessFilePath())
}
func (l *led) On() error {
if err := l.init(); err != nil {
return err
}
_, err := l.brightness.WriteString("1")
return err
}
func (l *led) Off() error {
if err := l.init(); err != nil {
return err
}
_, err := l.brightness.WriteString("0")
return err
}
func (l *led) isOn() (bool, error) {
l.brightness.Seek(0, 0)
bytes, err := ioutil.ReadAll(l.brightness)
if err != nil {
return false, err
}
str := string(bytes)
str = strings.TrimSpace(str)
if str == "1" {
return true, nil
}
return false, nil
}
func (l *led) Toggle() error {
if err := l.init(); err != nil {
return err
}
state, err := l.isOn()
if err != nil {
return err
}
if state {
return l.Off()
}
return l.On()
}
func (l *led) Close() error {
if !l.initialized {
return nil
}
if err := l.brightness.Close(); err != nil {
return err
}
l.initialized = false
return nil
}