mirror of https://github.com/kidoman/embd
115 lines
2.0 KiB
Go
115 lines
2.0 KiB
Go
package gpio
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import (
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"fmt"
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"os"
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"path"
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"github.com/kidoman/embd/gpio"
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)
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type digitalPin struct {
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n int
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dir *os.File
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val *os.File
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activeLow *os.File
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edge *os.File
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}
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func newDigitalPin(n int) (p *digitalPin, err error) {
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p = &digitalPin{n: n}
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err = p.init()
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return
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}
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func (p *digitalPin) init() (err error) {
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if p.dir, err = p.directionFile(); err != nil {
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return
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}
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if p.val, err = p.valueFile(); err != nil {
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return
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}
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if p.activeLow, err = p.activeLowFile(); err != nil {
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return
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}
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return
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}
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func (p *digitalPin) basePath() string {
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return fmt.Sprintf("/sys/class/gpio/gpio%v", p.n)
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}
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func (p *digitalPin) openFile(path string) (*os.File, error) {
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return os.OpenFile(path, os.O_RDWR, os.ModeExclusive)
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}
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func (p *digitalPin) directionFile() (*os.File, error) {
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return p.openFile(path.Join(p.basePath(), "direction"))
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}
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func (p *digitalPin) valueFile() (*os.File, error) {
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return p.openFile(path.Join(p.basePath(), "value"))
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}
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func (p *digitalPin) activeLowFile() (*os.File, error) {
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return p.openFile(path.Join(p.basePath(), "active_low"))
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}
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func (p *digitalPin) SetDir(dir gpio.Direction) (err error) {
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str := "in"
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if dir == gpio.Out {
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str = "out"
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}
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_, err = p.dir.WriteString(str)
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return
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}
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func (p *digitalPin) Read() (val int, err error) {
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buf := make([]byte, 1)
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if _, err = p.val.Read(buf); err != nil {
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return
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}
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val = 0
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if buf[0] == '1' {
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val = 1
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}
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return
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}
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func (p *digitalPin) Write(val int) (err error) {
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str := "0"
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if val == gpio.High {
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str = "1"
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}
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_, err = p.val.WriteString(str)
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return
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}
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func (p *digitalPin) ActiveLow(b bool) (err error) {
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str := "0"
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if b {
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str = "1"
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}
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_, err = p.activeLow.WriteString(str)
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return
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}
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func (p *digitalPin) Close() error {
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if err := p.dir.Close(); err != nil {
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return err
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}
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if err := p.val.Close(); err != nil {
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return err
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}
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if err := p.activeLow.Close(); err != nil {
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return err
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}
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if err := p.edge.Close(); err != nil {
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return err
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}
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return nil
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}
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