OneWire bus impl

host/all/all.go

@@ -2,6 +2,6 @@
 package all
 
 import (
-	_ "github.com/kidoman/embd/host/bbb"
-	_ "github.com/kidoman/embd/host/rpi"
+	_ "github.com/zlowred/embd/host/bbb"
+	_ "github.com/zlowred/embd/host/rpi"
 )

host/bbb/analogpin.go

@@ -9,7 +9,7 @@ import (
 	"strconv"
 	"strings"
 
-	"github.com/kidoman/embd"
+	"github.com/zlowred/embd"
 )
 
 type analogPin struct {

host/bbb/analogpin_test.go

@@ -3,7 +3,7 @@ package bbb
 import (
 	"testing"
 
-	"github.com/kidoman/embd"
+	"github.com/zlowred/embd"
 )
 
 func TestAnalogPinClose(t *testing.T) {

host/bbb/bbb.go

@@ -16,8 +16,8 @@ import (
 	"strings"
 
 	"github.com/golang/glog"
-	"github.com/kidoman/embd"
-	"github.com/kidoman/embd/host/generic"
+	"github.com/zlowred/embd"
+	"github.com/zlowred/embd/host/generic"
 )
 
 var pins = embd.PinMap{

host/bbb/pwmpin.go

@@ -11,8 +11,8 @@ import (
 	"time"
 
 	"github.com/golang/glog"
-	"github.com/kidoman/embd"
-	"github.com/kidoman/embd/util"
+	"github.com/zlowred/embd"
+	"github.com/zlowred/embd/util"
 )
 
 const (

host/bbb/pwmpin_test.go

@@ -3,7 +3,7 @@ package bbb
 import (
 	"testing"
 
-	"github.com/kidoman/embd"
+	"github.com/zlowred/embd"
 )
 
 func TestPWMPinClose(t *testing.T) {

host/generic/digitalpin.go

@@ -12,7 +12,7 @@ import (
 	"strconv"
 	"time"
 
-	"github.com/kidoman/embd"
+	"github.com/zlowred/embd"
 )
 
 type digitalPin struct {

host/generic/digitalpin_test.go

@@ -3,7 +3,7 @@ package generic
 import (
 	"testing"
 
-	"github.com/kidoman/embd"
+	"github.com/zlowred/embd"
 )
 
 func TestDigitalPinClose(t *testing.T) {

host/generic/i2cbus.go

@@ -12,7 +12,7 @@ import (
 	"unsafe"
 
 	"github.com/golang/glog"
-	"github.com/kidoman/embd"
+	"github.com/zlowred/embd"
 )
 
 const (

host/generic/interrupt.go

@@ -8,7 +8,7 @@ import (
 	"sync"
 	"syscall"
 
-	"github.com/kidoman/embd"
+	"github.com/zlowred/embd"
 )
 
 const (

host/generic/led.go

@@ -8,7 +8,7 @@ import (
 	"os"
 	"strings"
 
-	"github.com/kidoman/embd"
+	"github.com/zlowred/embd"
 )
 
 type led struct {

host/generic/spibus.go

@@ -8,7 +8,7 @@ import (
 	"unsafe"
 
 	"github.com/golang/glog"
-	"github.com/kidoman/embd"
+	"github.com/zlowred/embd"
 )
 
 const (

host/rpi/onewirebus.go

@@ -0,0 +1,192 @@
+// I²C support.
+
+package rpi
+
+import (
+	"fmt"
+	"os"
+	"sync"
+
+	"github.com/golang/glog"
+	"github.com/zlowred/embd"
+	"io/ioutil"
+)
+
+type w1Bus struct {
+	l    byte
+	busMap     map[string]embd.W1Device
+	mu   sync.Mutex
+
+	initialized bool
+}
+
+type w1Device struct {
+	file *os.File
+	addr string
+	mu   sync.Mutex
+
+	initialized bool
+}
+
+func NewW1Bus(l byte) embd.W1Bus {
+	fmt.Println("new w1 bus")
+	return &w1Bus{l: l, busMap: make(map[string]embd.W1Device)}
+}
+
+func (b *w1Bus) init() error {
+	if b.initialized {
+		return nil
+	}
+
+	var err error
+	if  _, err = os.Stat("/sys/bus/w1"); os.IsNotExist(err) {
+		return err
+	}
+
+	glog.V(2).Infof("onewire: bus %v initialized", b.l)
+
+	b.initialized = true
+
+	return nil
+}
+
+func (d *w1Device) init() error {
+	if d.initialized {
+		return nil
+	}
+
+	var err error
+	if d.file, err = os.OpenFile(fmt.Sprintf("/sys/bus/w1/devices/%s/rw", d.addr), os.O_RDWR, os.ModeExclusive); err != nil {
+		return err
+	}
+
+	glog.V(2).Infof("onewire: device %s initialized", d.addr)
+
+	d.initialized = true
+
+	return nil
+}
+
+func (d *w1Device) ReadByte() (byte, error) {
+	d.mu.Lock()
+	defer d.mu.Unlock()
+
+	if err := d.init(); err != nil {
+		return 0, err
+	}
+
+	bytes := make([]byte, 1)
+	n, _ := d.file.Read(bytes)
+
+	if n != 1 {
+		return 0, fmt.Errorf("onewire: Unexpected number (%v) of bytes read in ReadByte", n)
+	}
+
+	return bytes[0], nil
+}
+
+func (d *w1Device) WriteByte(value byte) error {
+	d.mu.Lock()
+	defer d.mu.Unlock()
+
+	if err := d.init(); err != nil {
+		return err
+	}
+
+	n, err := d.file.Write([]byte{value})
+
+	if n != 1 {
+		err = fmt.Errorf("onewire: Unexpected number (%v) of bytes written in WriteByte", n)
+	}
+
+	return err
+}
+
+func (d *w1Device) WriteBytes(value []byte) error {
+	d.mu.Lock()
+	defer d.mu.Unlock()
+
+	if err := d.init(); err != nil {
+		return err
+	}
+
+	for i := range value {
+		n, err := d.file.Write([]byte{value[i]})
+
+		if n != 1 {
+			return fmt.Errorf("onewire: Unexpected number (%v) of bytes written in WriteBytes", n)
+		}
+		if err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
+
+func (d *w1Device) ReadBytes(number int) (value []byte, err error) {
+	d.mu.Lock()
+	defer d.mu.Unlock()
+
+	if err := d.init(); err != nil {
+		return nil, err
+	}
+
+	bytes := make([]byte, number)
+	n, _ := d.file.Read(bytes)
+
+	if n != number {
+		return nil, fmt.Errorf("onewire: Unexpected number (%v) of bytes read in ReadBytes", n)
+	}
+
+	return bytes, nil
+}
+
+func (b *w1Bus) ListDevices() (devices []string, err error) {
+	dir, err := ioutil.ReadDir("/sys/bus/w1/devices/")
+	if err != nil {
+		return nil, err
+	}
+	devs := make([]string, len(dir))
+
+	for index, element := range dir {
+		devs[index] = element.Name()
+	}
+
+	return devs, nil
+}
+
+func (b *w1Bus) Open(address string) (device embd.W1Device, err error) {
+	b.mu.Lock()
+	defer b.mu.Unlock()
+
+	if d, ok := b.busMap[address]; ok {
+		return d, nil
+	}
+
+	d := &w1Device{addr: address}
+	b.busMap[address] = d
+	return d, nil
+}
+
+func (b *w1Bus) Close() error {
+	b.mu.Lock()
+	defer b.mu.Unlock()
+
+	for _, b := range b.busMap {
+		b.Close()
+	}
+
+	return nil
+}
+
+func (b *w1Device) Close() error {
+	b.mu.Lock()
+	defer b.mu.Unlock()
+
+	if !b.initialized {
+		return nil
+	}
+
+	return b.file.Close()
+}

host/rpi/rpi.go

@@ -5,12 +5,14 @@
 	GPIO (digital (rw))
 	I²C
 	LED
+	W1 - make sure that w1-gpio kernel module is loaded. If you wish to use it with sensors directly (e.g. DS18B20 etc) make sure to disable respective kernel modules (e.g. w1-therm) in /etc/modprobe.d/blacklist.conf.
 */
 package rpi
 
 import (
-	"github.com/kidoman/embd"
-	"github.com/kidoman/embd/host/generic"
+	"github.com/zlowred/embd"
+	"github.com/zlowred/embd/host/generic"
+	"fmt"
 )
 
 var spiDeviceMinor = byte(0)
@@ -73,6 +75,7 @@ var ledMap = embd.LEDMap{
 }
 
 func init() {
+	fmt.Println("registering RPI")
 	embd.Register(embd.HostRPi, func(rev int) *embd.Descriptor {
 		// Refer to http://elinux.org/RPi_HardwareHistory#Board_Revision_History
 		// for details.
@@ -97,6 +100,10 @@ func init() {
 			SPIDriver: func() embd.SPIDriver {
 				return embd.NewSPIDriver(spiDeviceMinor, generic.NewSPIBus, nil)
 			},
+			W1Driver: func() embd.W1Driver {
+				return embd.NewW1Driver(NewW1Bus)
+			},
 		}
 	})
+	fmt.Println("registered")
 }