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- add support for tmp006

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- refactor the i2c interface
This commit is contained in:
Karan Misra 2014-01-05 14:27:29 +05:30
parent 1a6f97f102
commit 0563d2be5c
9 changed files with 513 additions and 70 deletions
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146
i2c/i2c.go
View file

@ -22,22 +22,26 @@ const (
// A Bus implements access to the I2C two wire bus.
type Bus interface {
// Read a byte from the given address.
// ReadByte reads a byte from the given address.
ReadByte(addr byte) (value byte, err error)
// Write a byte to the given address.
// WriteByte writes a byte to the given address.
WriteByte(addr, value byte) error
// Write a bunch of bytes ot the given address.
// WriteBytes writes a slice bytes to the given address.
WriteBytes(addr byte, value []byte) error
// Read a bunch of bytes (len(value)) from the given address and register.
ReadFromReg(addr, reg byte, value []byte) (err error)
// Read a byte from the given address and register.
// ReadFromReg reads n (len(value)) bytes from the given address and register.
ReadFromReg(addr, reg byte, value []byte) error
// ReadByteFromReg reads a byte from the given address and register.
ReadByteFromReg(addr, reg byte) (value byte, err error)
// Read a int from the given address and register.
ReadInt(addr, reg byte) (value int, err error)
// ReadU16FromReg reads a unsigned 16 bit integer from the given address and register.
ReadWordFromReg(addr, reg byte) (value uint16, err error)
// Write a byte to the given address and register.
WriteToReg(addr, reg, value byte) error
// WriteToReg writes len(value) bytes to the given address and register.
WriteToReg(addr, reg byte, value []byte) error
// WriteByteToReg writes a byte to the given address and register.
WriteByteToReg(addr, reg, value byte) error
// WriteU16ToReg
WriteWordToReg(addr, reg byte, value uint16) error
}
type i2c_msg struct {
@ -108,7 +112,6 @@ func (b *bus) setAddress(addr byte) (err error) {
return
}
// Read a byte from the given address.
func (b *bus) ReadByte(addr byte) (value byte, err error) {
b.mu.Lock()
defer b.mu.Unlock()
@ -129,7 +132,6 @@ func (b *bus) ReadByte(addr byte) (value byte, err error) {
return
}
// Write a byte to the given address.
func (b *bus) WriteByte(addr, value byte) (err error) {
b.mu.Lock()
defer b.mu.Unlock()
@ -147,7 +149,6 @@ func (b *bus) WriteByte(addr, value byte) (err error) {
return
}
// Write a bunch of bytes ot the given address.
func (b *bus) WriteBytes(addr byte, value []byte) error {
b.mu.Lock()
defer b.mu.Unlock()
@ -172,7 +173,6 @@ func (b *bus) WriteBytes(addr byte, value []byte) error {
return nil
}
// Read a bunch of bytes (len(value)) from the given address and register.
func (b *bus) ReadFromReg(addr, reg byte, value []byte) (err error) {
b.mu.Lock()
defer b.mu.Unlock()
@ -206,7 +206,6 @@ func (b *bus) ReadFromReg(addr, reg byte, value []byte) (err error) {
return nil
}
// Read a byte from the given address and register.
func (b *bus) ReadByteFromReg(addr, reg byte) (value byte, err error) {
buf := make([]byte, 1)
if err = b.ReadFromReg(addr, reg, buf); err != nil {
@ -216,18 +215,16 @@ func (b *bus) ReadByteFromReg(addr, reg byte) (value byte, err error) {
return
}
// Read a int from the given address and register.
func (b *bus) ReadInt(addr, reg byte) (value int, err error) {
var buf = make([]byte, 2)
func (b *bus) ReadWordFromReg(addr, reg byte) (value uint16, err error) {
buf := make([]byte, 2)
if err = b.ReadFromReg(addr, reg, buf); err != nil {
return
}
value = int((int(buf[0]) << 8) | int(buf[1]))
value = uint16((uint16(buf[0]) << 8) | uint16(buf[1]))
return
}
// Write a byte to the given address and register.
func (b *bus) WriteToReg(addr, reg, value byte) (err error) {
func (b *bus) WriteToReg(addr, reg byte, value []byte) (err error) {
b.mu.Lock()
defer b.mu.Unlock()
@ -235,16 +232,81 @@ func (b *bus) WriteToReg(addr, reg, value byte) (err error) {
return
}
var outbuf [2]byte
outbuf := append([]byte{reg}, value...)
hdrp := (*reflect.SliceHeader)(unsafe.Pointer(&outbuf))
var message i2c_msg
message.addr = uint16(addr)
message.flags = 0
message.len = uint16(len(outbuf))
message.buf = uintptr(unsafe.Pointer(&hdrp.Data))
var packets i2c_rdwr_ioctl_data
packets.msgs = uintptr(unsafe.Pointer(&message))
packets.nmsg = 1
if _, _, errno := syscall.Syscall(syscall.SYS_IOCTL, b.file.Fd(), rdrwCmd, uintptr(unsafe.Pointer(&packets))); errno != 0 {
err = syscall.Errno(errno)
return
}
return
}
func (b *bus) WriteByteToReg(addr, reg, value byte) (err error) {
b.mu.Lock()
defer b.mu.Unlock()
if err = b.setAddress(addr); err != nil {
return
}
outbuf := [...]byte{
reg,
value,
}
var message i2c_msg
message.addr = uint16(addr)
message.flags = 0
message.len = uint16(len(outbuf))
message.buf = uintptr(unsafe.Pointer(&outbuf))
var packets i2c_rdwr_ioctl_data
packets.msgs = uintptr(unsafe.Pointer(&message))
packets.nmsg = 1
if _, _, errno := syscall.Syscall(syscall.SYS_IOCTL, b.file.Fd(), rdrwCmd, uintptr(unsafe.Pointer(&packets))); errno != 0 {
err = syscall.Errno(errno)
return
}
return
}
func (b *bus) WriteWordToReg(addr, reg byte, value uint16) (err error) {
b.mu.Lock()
defer b.mu.Unlock()
if err = b.setAddress(addr); err != nil {
return
}
outbuf := [...]byte{
reg,
byte(value >> 8),
byte(value),
}
var messages i2c_msg
messages.addr = uint16(addr)
messages.flags = 0
messages.len = uint16(len(outbuf))
messages.buf = uintptr(unsafe.Pointer(&outbuf))
outbuf[0] = reg
outbuf[1] = value
var packets i2c_rdwr_ioctl_data
packets.msgs = uintptr(unsafe.Pointer(&messages))
@ -258,37 +320,47 @@ func (b *bus) WriteToReg(addr, reg, value byte) (err error) {
return
}
// Read a byte from the given address.
// ReadByte reads a byte from the given address.
func ReadByte(addr byte) (value byte, err error) {
return Default.ReadByte(addr)
}
// Write a byte to the given address.
func WriteByte(addr, value byte) (err error) {
// WriteByte writes a byte to the given address.
func WriteByte(addr, value byte) error {
return Default.WriteByte(addr, value)
}
// Write a bunch of bytes ot the given address.
// WriteBytes writes a slice bytes to the given address.
func WriteBytes(addr byte, value []byte) error {
return Default.WriteBytes(addr, value)
}
// Read a bunch of bytes (len(value)) from the given address and register.
func ReadFromReg(addr, reg byte, value []byte) (err error) {
// ReadFromReg reads n (len(value)) bytes from the given address and register.
func ReadFromReg(addr, reg byte, value []byte) error {
return Default.ReadFromReg(addr, reg, value)
}
// Read a byte from the given address and register.
// ReadByteFromReg reads a byte from the given address and register.
func ReadByteFromReg(addr, reg byte) (value byte, err error) {
return Default.ReadByteFromReg(addr, reg)
}
// Read a int from the given address and register.
func ReadInt(addr, reg byte) (value int, err error) {
return Default.ReadInt(addr, reg)
// ReadU16FromReg reads a unsigned 16 bit integer from the given address and register.
func ReadWordFromReg(addr, reg byte) (value uint16, err error) {
return Default.ReadWordFromReg(addr, reg)
}
// Write a byte to the given address and register.
func WriteToReg(addr, reg, value byte) (err error) {
// WriteToReg writes len(value) bytes to the given address and register.
func WriteToReg(addr, reg byte, value []byte) error {
return Default.WriteToReg(addr, reg, value)
}
// WriteByteToReg writes a byte to the given address and register.
func WriteByteToReg(addr, reg, value byte) error {
return Default.WriteByteToReg(addr, reg, value)
}
// WriteU16ToReg
func WriteWordToReg(addr, reg byte, value uint16) error {
return Default.WriteWordToReg(addr, reg, value)
}