935a293106
* machine/i2c: add interface check and placeholder implementation where missing for SetBaudRate()
92 строки
3,3 КиБ
Go
92 строки
3,3 КиБ
Go
//go:build atmega || nrf || sam || stm32 || fe310 || k210 || rp2040 || mimxrt1062
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package machine
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import (
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"errors"
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)
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// If you are getting a compile error on this line please check to see you've
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// correctly implemented the methods on the I2C type. They must match
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// the i2cController interface method signatures type to type perfectly.
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// If not implementing the I2C type please remove your target from the build tags
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// at the top of this file.
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var _ interface { // 2
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Configure(config I2CConfig) error
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Tx(addr uint16, w, r []byte) error
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SetBaudRate(br uint32) error
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} = (*I2C)(nil)
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// TWI_FREQ is the I2C bus speed. Normally either 100 kHz, or 400 kHz for high-speed bus.
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//
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// Deprecated: use 100 * machine.KHz or 400 * machine.KHz instead.
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const (
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TWI_FREQ_100KHZ = 100000
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TWI_FREQ_400KHZ = 400000
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)
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var (
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errI2CWriteTimeout = errors.New("I2C timeout during write")
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errI2CReadTimeout = errors.New("I2C timeout during read")
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errI2CBusReadyTimeout = errors.New("I2C timeout on bus ready")
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errI2CSignalStartTimeout = errors.New("I2C timeout on signal start")
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errI2CSignalReadTimeout = errors.New("I2C timeout on signal read")
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errI2CSignalStopTimeout = errors.New("I2C timeout on signal stop")
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errI2CAckExpected = errors.New("I2C error: expected ACK not NACK")
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errI2CBusError = errors.New("I2C bus error")
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errI2COverflow = errors.New("I2C receive buffer overflow")
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errI2COverread = errors.New("I2C transmit buffer overflow")
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errI2CNotImplemented = errors.New("I2C operation not yet implemented")
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)
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// I2CTargetEvent reflects events on the I2C bus
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type I2CTargetEvent uint8
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const (
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// I2CReceive indicates target has received a message from the controller.
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I2CReceive I2CTargetEvent = iota
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// I2CRequest indicates the controller is expecting a message from the target.
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I2CRequest
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// I2CFinish indicates the controller has ended the transaction.
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//
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// I2C controllers can chain multiple receive/request messages without
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// relinquishing the bus by doing 'restarts'. I2CFinish indicates the
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// bus has been relinquished by an I2C 'stop'.
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I2CFinish
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)
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// I2CMode determines if an I2C peripheral is in Controller or Target mode.
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type I2CMode int
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const (
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// I2CModeController represents an I2C peripheral in controller mode.
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I2CModeController I2CMode = iota
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// I2CModeTarget represents an I2C peripheral in target mode.
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I2CModeTarget
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)
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// WriteRegister transmits first the register and then the data to the
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// peripheral device.
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//
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// Many I2C-compatible devices are organized in terms of registers. This method
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// is a shortcut to easily write to such registers. Also, it only works for
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// devices with 7-bit addresses, which is the vast majority.
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func (i2c *I2C) WriteRegister(address uint8, register uint8, data []byte) error {
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buf := make([]uint8, len(data)+1)
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buf[0] = register
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copy(buf[1:], data)
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return i2c.Tx(uint16(address), buf, nil)
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}
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// ReadRegister transmits the register, restarts the connection as a read
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// operation, and reads the response.
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//
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// Many I2C-compatible devices are organized in terms of registers. This method
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// is a shortcut to easily read such registers. Also, it only works for devices
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// with 7-bit addresses, which is the vast majority.
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func (i2c *I2C) ReadRegister(address uint8, register uint8, data []byte) error {
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return i2c.Tx(uint16(address), []byte{register}, data)
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}
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