mirror of https://github.com/kidoman/embd
99 lines
3.2 KiB
Go
99 lines
3.2 KiB
Go
/*
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* Copyright (c) Karan Misra 2014
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*
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* Permission is hereby granted, free of charge, to any person obtaining a copy of this software and
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* associated documentation files (the "Software"), to deal in the Software without restriction,
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* including without limitation the rights to use, copy, modify, merge, publish, distribute,
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* sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is
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* furnished to do so, subject to the following conditions:
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*
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* The above copyright notice and this permission notice shall be included in all copies or
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* substantial portions of the Software.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT
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* NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
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* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
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* DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
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*/
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// I2C support.
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package embd
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// I2CBus interface is used to interact with the I2C bus.
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type I2CBus interface {
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// ReadByte reads a byte from the given address.
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ReadByte(addr byte) (value byte, err error)
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// ReadBytes reads a slice of bytes from the given address.
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ReadBytes(addr byte, num int) (value []byte, err error)
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// WriteByte writes a byte to the given address.
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WriteByte(addr, value byte) error
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// WriteBytes writes a slice bytes to the given address.
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WriteBytes(addr byte, value []byte) error
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// ReadFromReg reads n (len(value)) bytes from the given address and register.
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ReadFromReg(addr, reg byte, value []byte) error
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// ReadByteFromReg reads a byte from the given address and register.
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ReadByteFromReg(addr, reg byte) (value byte, err error)
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// ReadU16FromReg reads a unsigned 16 bit integer from the given address and register.
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ReadWordFromReg(addr, reg byte) (value uint16, err error)
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// WriteToReg writes len(value) bytes to the given address and register.
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WriteToReg(addr, reg byte, value []byte) error
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// WriteByteToReg writes a byte to the given address and register.
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WriteByteToReg(addr, reg, value byte) error
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// WriteU16ToReg
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WriteWordToReg(addr, reg byte, value uint16) error
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// Close releases the resources associated with the bus.
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Close() error
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}
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// I2CDriver interface interacts with the host descriptors to allow us
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// control of I2C communication.
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type I2CDriver interface {
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Bus(l byte) I2CBus
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// Close releases the resources associated with the driver.
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Close() error
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}
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var i2cDriverInitialized bool
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var i2cDriverInstance I2CDriver
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// InitI2C initializes the I2C driver.
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func InitI2C() error {
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if i2cDriverInitialized {
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return nil
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}
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desc, err := DescribeHost()
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if err != nil {
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return err
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}
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if desc.I2CDriver == nil {
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return ErrFeatureNotSupported
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}
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i2cDriverInstance = desc.I2CDriver()
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i2cDriverInitialized = true
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return nil
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}
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// CloseI2C releases resources associated with the I2C driver.
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func CloseI2C() error {
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return i2cDriverInstance.Close()
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}
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// NewI2CBus returns a I2CBus.
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func NewI2CBus(l byte) I2CBus {
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if err := InitI2C(); err != nil {
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panic(err)
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}
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return i2cDriverInstance.Bus(l)
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}
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