Introduce I2cBusAdaptor for composition in platforms

drivers/i2c/adafruit_driver.go

@@ -199,7 +199,7 @@ func (a *AdafruitMotorHatDriver) startDriver(connection Connection) (err error)
 
 // Start initializes both I2C-addressable Adafruit Motor HAT drivers
 func (a *AdafruitMotorHatDriver) Start() (err error) {
-	bus := a.GetBusOrDefault(a.connector.GetDefaultBus())
+	bus := a.GetBusOrDefault(a.connector.DefaultBus())
 
 	err = a.startServoHat(bus)
 	if adafruitDebug && err != nil {

drivers/i2c/bh1750_driver.go

@@ -1,8 +1,8 @@
 package i2c
 
 import (
-	"time"
 	"errors"
+	"time"
 
 	"gobot.io/x/gobot"
 )
@@ -44,7 +44,7 @@ func NewBH1750Driver(a Connector, options ...func(Config)) *BH1750Driver {
 		name:      gobot.DefaultName("BH1750"),
 		connector: a,
 		Config:    NewConfig(),
-		mode: BH1750_CONTINUOUS_HIGH_RES_MODE,
+		mode:      BH1750_CONTINUOUS_HIGH_RES_MODE,
 	}
 
 	for _, option := range options {
@@ -66,7 +66,7 @@ func (h *BH1750Driver) Connection() gobot.Connection { return h.connector.(gobot
 
 // Start initialized the bh1750
 func (h *BH1750Driver) Start() (err error) {
-	bus := h.GetBusOrDefault(h.connector.GetDefaultBus())
+	bus := h.GetBusOrDefault(h.connector.DefaultBus())
 	address := h.GetAddressOrDefault(bh1750Address)
 
 	h.connection, err = h.connector.GetConnection(address, bus)

drivers/i2c/blinkm_driver.go

@@ -76,7 +76,7 @@ func (b *BlinkMDriver) Connection() gobot.Connection { return b.connection.(gobo
 
 // Start starts the Driver up, and writes start command
 func (b *BlinkMDriver) Start() (err error) {
-	bus := b.GetBusOrDefault(b.connector.GetDefaultBus())
+	bus := b.GetBusOrDefault(b.connector.DefaultBus())
 	address := b.GetAddressOrDefault(blinkmAddress)
 
 	b.connection, err = b.connector.GetConnection(address, bus)

drivers/i2c/drv2605l_driver.go

@@ -136,7 +136,7 @@ func (d *DRV2605LDriver) writeByteRegisters(regValPairs []struct{ reg, val uint8
 }
 
 func (d *DRV2605LDriver) initialize() (err error) {
-	bus := d.GetBusOrDefault(d.connector.GetDefaultBus())
+	bus := d.GetBusOrDefault(d.connector.DefaultBus())
 	address := d.GetAddressOrDefault(drv2605Address)
 
 	d.connection, err = d.connector.GetConnection(address, bus)

drivers/i2c/helpers_test.go

@@ -164,7 +164,7 @@ func (t *i2cTestAdaptor) GetConnection(address int, bus int) (connection Connect
 	return t, nil
 }
 
-func (t *i2cTestAdaptor) GetDefaultBus() int {
+func (t *i2cTestAdaptor) DefaultBus() int {
 	return 0
 }
 

drivers/i2c/hmc6352_driver.go

@@ -45,7 +45,7 @@ func (h *HMC6352Driver) Connection() gobot.Connection { return h.connector.(gobo
 
 // Start initializes the hmc6352
 func (h *HMC6352Driver) Start() (err error) {
-	bus := h.GetBusOrDefault(h.connector.GetDefaultBus())
+	bus := h.GetBusOrDefault(h.connector.DefaultBus())
 	address := h.GetAddressOrDefault(hmc6352Address)
 
 	h.connection, err = h.connector.GetConnection(address, bus)

drivers/i2c/i2c_connection.go

@@ -95,13 +95,13 @@ type I2cDevice interface {
 // Connector lets Adaptors provide the interface for Drivers
 // to get access to the I2C buses on platforms that support I2C.
 type Connector interface {
-	// GetConnection returns a connection to device at the specified address
+	// GetConnection creates and returns a connection to device at the specified address
 	// and bus. Bus numbering starts at index 0, the range of valid buses is
 	// platform specific.
-	GetConnection(address int, bus int) (device Connection, err error)
+	GetConnection(address int, busNr int) (device Connection, err error)
 
-	// GetDefaultBus returns the default I2C bus index
-	GetDefaultBus() int
+	// DefaultBus returns the default I2C bus index
+	DefaultBus() int
 }
 
 // Connection is a connection to an I2C device with a specified address

drivers/i2c/i2c_driver.go

@@ -63,7 +63,7 @@ func (d *Driver) Start() error {
 	defer d.mutex.Unlock()
 
 	var err error
-	bus := d.GetBusOrDefault(d.connector.GetDefaultBus())
+	bus := d.GetBusOrDefault(d.connector.DefaultBus())
 	address := d.GetAddressOrDefault(int(d.defaultAddress))
 
 	if d.connection, err = d.connector.GetConnection(address, bus); err != nil {

drivers/i2c/ina3221_driver.go

@@ -91,7 +91,7 @@ func (i *INA3221Driver) Connection() gobot.Connection {
 // Start initializes the INA3221
 func (i *INA3221Driver) Start() error {
 	var err error
-	bus := i.GetBusOrDefault(i.connector.GetDefaultBus())
+	bus := i.GetBusOrDefault(i.connector.DefaultBus())
 	address := i.GetAddressOrDefault(int(ina3221Address))
 
 	if i.connection, err = i.connector.GetConnection(address, bus); err != nil {

drivers/i2c/jhd1313m1_driver.go

@@ -144,7 +144,7 @@ func (h *JHD1313M1Driver) Connection() gobot.Connection {
 
 // Start starts the backlit and the screen and initializes the states.
 func (h *JHD1313M1Driver) Start() (err error) {
-	bus := h.GetBusOrDefault(h.connector.GetDefaultBus())
+	bus := h.GetBusOrDefault(h.connector.DefaultBus())
 
 	if h.lcdConnection, err = h.connector.GetConnection(h.lcdAddress, bus); err != nil {
 		return err

drivers/i2c/lidarlite_driver.go

@@ -51,7 +51,7 @@ func (h *LIDARLiteDriver) Connection() gobot.Connection { return h.connector.(go
 
 // Start initialized the LIDAR
 func (h *LIDARLiteDriver) Start() (err error) {
-	bus := h.GetBusOrDefault(h.connector.GetDefaultBus())
+	bus := h.GetBusOrDefault(h.connector.DefaultBus())
 	address := h.GetAddressOrDefault(lidarliteAddress)
 
 	h.connection, err = h.connector.GetConnection(address, bus)

drivers/i2c/mma7660_driver.go

@@ -71,7 +71,7 @@ func (h *MMA7660Driver) Connection() gobot.Connection { return h.connector.(gobo
 
 // Start initialized the mma7660
 func (h *MMA7660Driver) Start() (err error) {
-	bus := h.GetBusOrDefault(h.connector.GetDefaultBus())
+	bus := h.GetBusOrDefault(h.connector.DefaultBus())
 	address := h.GetAddressOrDefault(mma7660Address)
 
 	h.connection, err = h.connector.GetConnection(address, bus)

drivers/i2c/pca9501_driver.go

@@ -151,7 +151,7 @@ func (p *PCA9501Driver) WriteEEPROM(address uint8, val uint8) error {
 
 func (p *PCA9501Driver) initialize() (err error) {
 	// initialize the EEPROM connection
-	bus := p.GetBusOrDefault(p.connector.GetDefaultBus())
+	bus := p.GetBusOrDefault(p.connector.DefaultBus())
 	addressMem := p.GetAddressOrDefault(pca9501DefaultAddress) | 0x40
 	p.connectionMem, err = p.connector.GetConnection(addressMem, bus)
 	return

drivers/i2c/pca9685_driver.go

@@ -100,7 +100,7 @@ func (p *PCA9685Driver) Connection() gobot.Connection { return p.connector.(gobo
 
 // Start initializes the pca9685
 func (p *PCA9685Driver) Start() (err error) {
-	bus := p.GetBusOrDefault(p.connector.GetDefaultBus())
+	bus := p.GetBusOrDefault(p.connector.DefaultBus())
 	address := p.GetAddressOrDefault(pca9685Address)
 
 	p.connection, err = p.connector.GetConnection(address, bus)

drivers/i2c/pcf8591_driver.go

@@ -189,7 +189,7 @@ func (p *PCF8591Driver) Connection() gobot.Connection { return p.connector.(gobo
 
 // Start initializes the PCF8591
 func (p *PCF8591Driver) Start() (err error) {
-	bus := p.GetBusOrDefault(p.connector.GetDefaultBus())
+	bus := p.GetBusOrDefault(p.connector.DefaultBus())
 	address := p.GetAddressOrDefault(pcf8591DefaultAddress)
 
 	p.connection, err = p.connector.GetConnection(address, bus)

drivers/i2c/sht2x_driver.go

@@ -118,7 +118,7 @@ func (d *SHT2xDriver) Connection() gobot.Connection { return d.connector.(gobot.
 
 // Start initializes the SHT2x
 func (d *SHT2xDriver) Start() (err error) {
-	bus := d.GetBusOrDefault(d.connector.GetDefaultBus())
+	bus := d.GetBusOrDefault(d.connector.DefaultBus())
 	address := d.GetAddressOrDefault(SHT2xDefaultAddress)
 
 	if d.connection, err = d.connector.GetConnection(address, bus); err != nil {

drivers/i2c/sht3x_driver.go

@@ -102,7 +102,7 @@ func (s *SHT3xDriver) Connection() gobot.Connection { return s.connector.(gobot.
 
 // Start initializes the SHT3x
 func (s *SHT3xDriver) Start() (err error) {
-	bus := s.GetBusOrDefault(s.connector.GetDefaultBus())
+	bus := s.GetBusOrDefault(s.connector.DefaultBus())
 	address := s.GetAddressOrDefault(s.sht3xAddress)
 
 	s.connection, err = s.connector.GetConnection(address, bus)

drivers/i2c/ssd1306_driver.go

@@ -282,7 +282,7 @@ func (s *SSD1306Driver) Start() (err error) {
 		s.initSequence.contrast = 0x9F
 		s.initSequence.prechargePeriod = 0x22
 	}
-	bus := s.GetBusOrDefault(s.connector.GetDefaultBus())
+	bus := s.GetBusOrDefault(s.connector.DefaultBus())
 	address := s.GetAddressOrDefault(ssd1306I2CAddress)
 	s.connection, err = s.connector.GetConnection(address, bus)
 	if err != nil {

drivers/i2c/tsl2561_driver.go

@@ -231,7 +231,7 @@ func (d *TSL2561Driver) Connection() gobot.Connection {
 
 // Start initializes the device.
 func (d *TSL2561Driver) Start() (err error) {
-	bus := d.GetBusOrDefault(d.connector.GetDefaultBus())
+	bus := d.GetBusOrDefault(d.connector.DefaultBus())
 	address := d.GetAddressOrDefault(TSL2561AddressFloat)
 
 	if d.connection, err = d.connector.GetConnection(address, bus); err != nil {

drivers/i2c/wiichuck_driver.go

@@ -86,7 +86,7 @@ func (w *WiichuckDriver) Connection() gobot.Connection { return w.connector.(gob
 // Start initilizes i2c and reads from adaptor
 // using specified interval to update with new value
 func (w *WiichuckDriver) Start() (err error) {
-	bus := w.GetBusOrDefault(w.connector.GetDefaultBus())
+	bus := w.GetBusOrDefault(w.connector.DefaultBus())
 	address := w.GetAddressOrDefault(wiichuckAddress)
 
 	w.connection, err = w.connector.GetConnection(address, bus)

drivers/spi/spi.go

@@ -17,6 +17,8 @@ type Operations interface {
 	Tx(w, r []byte) error
 }
 
+// TODO: rename to golang getter spec (no prefix "Get" for simple getters)
+
 // Connector lets Adaptors provide the interface for Drivers
 // to get access to the SPI buses on platforms that support SPI.
 type Connector interface {

examples/edison_blink.go

@@ -12,14 +12,12 @@ import (
 	"gobot.io/x/gobot/platforms/intel-iot/edison"
 )
 
+const boardType = "arduino" // "sparkfun" for a Sparkfun Edison board with the GPIO block
+
 func main() {
-	e := edison.NewAdaptor()
+	e := edison.NewAdaptor(boardType)
 	led := gpio.NewLedDriver(e, "13")
 
-	// Uncomment the line below if you are using a Sparkfun
-	// Edison board with the GPIO block
-	// e.SetBoard("sparkfun")
-
 	work := func() {
 		gobot.Every(1*time.Second, func() {
 			led.Toggle()

examples/edison_miniboard_grove_accelerometer.go

@@ -14,8 +14,7 @@ import (
 )
 
 func main() {
-	board := edison.NewAdaptor()
-	board.SetBoard("miniboard")
+	board := edison.NewAdaptor("miniboard")
 
 	accel := i2c.NewGroveAccelerometerDriver(board)
 

platforms/adaptors/digitalpinsadaptor_test.go

@@ -107,6 +107,7 @@ func TestDigitalPinsReConnect(t *testing.T) {
 	err := a.Connect()
 	// assert
 	gobottest.Assert(t, err, nil)
+	gobottest.Refute(t, a.pins, nil)
 	gobottest.Assert(t, len(a.pins), 0)
 }
 

platforms/adaptors/i2cbusadaptor.go

@@ -0,0 +1,86 @@
+package adaptors
+
+import (
+	"fmt"
+	"sync"
+
+	multierror "github.com/hashicorp/go-multierror"
+	"gobot.io/x/gobot/drivers/i2c"
+	"gobot.io/x/gobot/system"
+)
+
+type i2cBusNumberValidator func(busNumber int) error
+
+// I2cBusAdaptor is a adaptor for i2c bus, normally used for composition in platforms.
+type I2cBusAdaptor struct {
+	sys              *system.Accesser
+	validateNumber   i2cBusNumberValidator
+	defaultBusNumber int
+	mutex            sync.Mutex
+	buses            map[int]i2c.I2cDevice
+}
+
+// NewI2cBusAdaptor provides the access to i2c buses of the board. The validator is used to check the bus number,
+// which is given by user, to the abilities of the board.
+func NewI2cBusAdaptor(sys *system.Accesser, v i2cBusNumberValidator, defaultBusNr int) *I2cBusAdaptor {
+	a := &I2cBusAdaptor{
+		sys:              sys,
+		validateNumber:   v,
+		defaultBusNumber: defaultBusNr,
+	}
+	return a
+}
+
+// Connect prepares the connection to i2c buses.
+func (a *I2cBusAdaptor) Connect() error {
+	a.mutex.Lock()
+	defer a.mutex.Unlock()
+
+	a.buses = make(map[int]i2c.I2cDevice)
+	return nil
+}
+
+// Finalize closes all i2c connections.
+func (a *I2cBusAdaptor) Finalize() error {
+	a.mutex.Lock()
+	defer a.mutex.Unlock()
+
+	var err error
+	for _, bus := range a.buses {
+		if bus != nil {
+			if e := bus.Close(); e != nil {
+				err = multierror.Append(err, e)
+			}
+		}
+	}
+	a.buses = nil
+	return err
+}
+
+// GetConnection returns a connection to a device on a specified i2c bus
+func (a *I2cBusAdaptor) GetConnection(address int, busNr int) (connection i2c.Connection, err error) {
+	a.mutex.Lock()
+	defer a.mutex.Unlock()
+
+	if a.buses == nil {
+		return nil, fmt.Errorf("not connected")
+	}
+
+	bus := a.buses[busNr]
+	if bus == nil {
+		if err := a.validateNumber(busNr); err != nil {
+			return nil, err
+		}
+		bus, err = a.sys.NewI2cDevice(fmt.Sprintf("/dev/i2c-%d", busNr))
+		if err != nil {
+			return nil, err
+		}
+		a.buses[busNr] = bus
+	}
+	return i2c.NewConnection(bus, address), err
+}
+
+// GetDefaultBus returns the default i2c bus number for this platform.
+func (a *I2cBusAdaptor) DefaultBus() int {
+	return a.defaultBusNumber
+}