137 lines
3.8 KiB
Go
137 lines
3.8 KiB
Go
package i2c
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import (
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"errors"
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"gobot.io/x/gobot/sysfs"
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)
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const (
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// Error event
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Error = "error"
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)
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const (
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// BusNotInitialized is the initial value for a bus
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BusNotInitialized = -1
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// AddressNotInitialized is the initial value for an address
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AddressNotInitialized = -1
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)
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var (
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ErrEncryptedBytes = errors.New("Encrypted bytes")
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ErrNotEnoughBytes = errors.New("Not enough bytes read")
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ErrNotReady = errors.New("Device is not ready")
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ErrInvalidPosition = errors.New("Invalid position value")
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)
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// Connector lets Adaptors provide the interface for Drivers
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// to get access to the I2C buses on platforms that support I2C.
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type Connector interface {
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// GetConnection returns a connection to device at the specified address
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// and bus. Bus numbering starts at index 0, the range of valid buses is
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// platform specific.
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GetConnection(address int, bus int) (device Connection, err error)
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// GetDefaultBus returns the default I2C bus index
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GetDefaultBus() int
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}
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// Connection is a connection to an I2C device with a specified address
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// on a specific bus. Used as an alternative to the I2c interface.
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// Implements sysfs.I2cOperations to talk to the device, wrapping the
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// calls in SetAddress to always target the specified device.
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// Provided by an Adaptor by implementing the I2cConnector interface.
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type Connection sysfs.I2cOperations
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type i2cConnection struct {
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bus sysfs.I2cDevice
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address int
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}
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// NewConnection creates and returns a new connection to a specific
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// i2c device on a bus and address.
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func NewConnection(bus sysfs.I2cDevice, address int) (connection *i2cConnection) {
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return &i2cConnection{bus: bus, address: address}
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}
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// Read data from an i2c device.
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func (c *i2cConnection) Read(data []byte) (read int, err error) {
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if err = c.bus.SetAddress(c.address); err != nil {
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return 0, err
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}
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read, err = c.bus.Read(data)
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return
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}
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// Write data to an i2c device.
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func (c *i2cConnection) Write(data []byte) (written int, err error) {
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if err = c.bus.SetAddress(c.address); err != nil {
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return 0, err
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}
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written, err = c.bus.Write(data)
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return
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}
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// Close connection to i2c device.
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func (c *i2cConnection) Close() error {
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return c.bus.Close()
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}
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// ReadByte reads a single byte from the i2c device.
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func (c *i2cConnection) ReadByte() (val byte, err error) {
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if err := c.bus.SetAddress(c.address); err != nil {
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return 0, err
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}
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return c.bus.ReadByte()
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}
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// ReadByteData reads a byte value for a register on the i2c device.
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func (c *i2cConnection) ReadByteData(reg uint8) (val uint8, err error) {
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if err := c.bus.SetAddress(c.address); err != nil {
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return 0, err
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}
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return c.bus.ReadByteData(reg)
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}
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// ReadWordData reads a word value for a register on the i2c device.
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func (c *i2cConnection) ReadWordData(reg uint8) (val uint16, err error) {
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if err := c.bus.SetAddress(c.address); err != nil {
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return 0, err
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}
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return c.bus.ReadWordData(reg)
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}
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// WriteByte writes a single byte to the i2c device.
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func (c *i2cConnection) WriteByte(val byte) (err error) {
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if err := c.bus.SetAddress(c.address); err != nil {
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return err
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}
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return c.bus.WriteByte(val)
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}
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// WriteByteData writes a byte value to a register on the i2c device.
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func (c *i2cConnection) WriteByteData(reg uint8, val uint8) (err error) {
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if err := c.bus.SetAddress(c.address); err != nil {
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return err
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}
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return c.bus.WriteByteData(reg, val)
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}
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// WriteWordData writes a word value to a register on the i2c device.
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func (c *i2cConnection) WriteWordData(reg uint8, val uint16) (err error) {
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if err := c.bus.SetAddress(c.address); err != nil {
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return err
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}
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return c.bus.WriteWordData(reg, val)
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}
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// WriteBlockData writes a block of bytes to a register on the i2c device.
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func (c *i2cConnection) WriteBlockData(reg uint8, b []byte) (err error) {
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if err := c.bus.SetAddress(c.address); err != nil {
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return err
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}
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return c.bus.WriteBlockData(reg, b)
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}
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