I2C Configuration Functions
[Hal]

# Defined behavior * i2c_init initializes i2c_t control structure * i2c_init configures the pins used by I2C * i2c_free returns the pins owned by the I2C object to their reset state * i2c_frequency configure the I2C frequency * i2c_start sends START command * i2c_read reads `length` bytes from the I2C slave specified by `address` to the `data` buffer * i2c_read reads generates a stop condition on the bus at the end of the transfer if `stop` parameter is non-zero * i2c_read reads returns the number of symbols received from the bus * i2c_write writes `length` bytes to the I2C slave specified by `address` from the `data` buffer * i2c_write generates a stop condition on the bus at the end of the transfer if `stop` parameter is non-zero * i2c_write returns zero on success, error code otherwise * i2c_reset resets the I2C peripheral * i2c_byte_read reads and return one byte from the specfied I2C slave * i2c_byte_read uses `last` parameter to inform the slave that all bytes have been read * i2c_byte_write writes one byte to the specified I2C slave * i2c_byte_write returns 0 if NAK was received, 1 if ACK was received, 2 for timeout * i2c_slave_mode enables/disables I2S slave mode * i2c_slave_receive returns: 1 - read addresses, 2 - write to all slaves, 3 write addressed, 0 - the slave has not been addressed * i2c_slave_read reads `length` bytes from the I2C master to the `data` buffer * i2c_slave_read returns non-zero if a value is available, 0 otherwise * i2c_slave_write writes `length` bytes to the I2C master from the `data` buffer * i2c_slave_write returns non-zero if a value is available, 0 otherwise * i2c_slave_address configures I2C slave address * i2c_transfer_asynch starts I2C asynchronous transfer * i2c_transfer_asynch writes `tx_length` bytes to the I2C slave specified by `address` from the `tx` buffer * i2c_transfer_asynch reads `rx_length` bytes from the I2C slave specified by `address` to the `rx` buffer * i2c_transfer_asynch generates a stop condition on the bus at the end of the transfer if `stop` parameter is non-zero * The callback given to i2c_transfer_asynch is invoked when the transfer completes * i2c_transfer_asynch specifies the logical OR of events to be registered * The i2c_transfer_asynch function may use the `DMAUsage` hint to select the appropriate async algorithm * i2c_irq_handler_asynch returns event flags if a transfer termination condition was met, otherwise returns 0. More...

Detailed Description

# Defined behavior * i2c_init initializes i2c_t control structure * i2c_init configures the pins used by I2C * i2c_free returns the pins owned by the I2C object to their reset state * i2c_frequency configure the I2C frequency * i2c_start sends START command * i2c_read reads `length` bytes from the I2C slave specified by `address` to the `data` buffer * i2c_read reads generates a stop condition on the bus at the end of the transfer if `stop` parameter is non-zero * i2c_read reads returns the number of symbols received from the bus * i2c_write writes `length` bytes to the I2C slave specified by `address` from the `data` buffer * i2c_write generates a stop condition on the bus at the end of the transfer if `stop` parameter is non-zero * i2c_write returns zero on success, error code otherwise * i2c_reset resets the I2C peripheral * i2c_byte_read reads and return one byte from the specfied I2C slave * i2c_byte_read uses `last` parameter to inform the slave that all bytes have been read * i2c_byte_write writes one byte to the specified I2C slave * i2c_byte_write returns 0 if NAK was received, 1 if ACK was received, 2 for timeout * i2c_slave_mode enables/disables I2S slave mode * i2c_slave_receive returns: 1 - read addresses, 2 - write to all slaves, 3 write addressed, 0 - the slave has not been addressed * i2c_slave_read reads `length` bytes from the I2C master to the `data` buffer * i2c_slave_read returns non-zero if a value is available, 0 otherwise * i2c_slave_write writes `length` bytes to the I2C master from the `data` buffer * i2c_slave_write returns non-zero if a value is available, 0 otherwise * i2c_slave_address configures I2C slave address * i2c_transfer_asynch starts I2C asynchronous transfer * i2c_transfer_asynch writes `tx_length` bytes to the I2C slave specified by `address` from the `tx` buffer * i2c_transfer_asynch reads `rx_length` bytes from the I2C slave specified by `address` to the `rx` buffer * i2c_transfer_asynch generates a stop condition on the bus at the end of the transfer if `stop` parameter is non-zero * The callback given to i2c_transfer_asynch is invoked when the transfer completes * i2c_transfer_asynch specifies the logical OR of events to be registered * The i2c_transfer_asynch function may use the `DMAUsage` hint to select the appropriate async algorithm * i2c_irq_handler_asynch returns event flags if a transfer termination condition was met, otherwise returns 0.

* i2c_active returns non-zero if the I2C module is active or 0 if it is not * i2c_abort_asynch aborts an on-going async transfer

# Undefined behavior * Calling i2c_init multiple times on the same `i2c_t` * Calling any function other than i2c_init on a non-initialized `i2c_t` * Initialising the `I2C` peripheral with invalid `SDA` and `SCL` pins. * Passing pins that cannot be on the same peripheral * Passing an invalid pointer as `obj` to any function * Use of a `null` pointer as an argument to any function. * Initialising the peripheral in slave mode if slave mode is not supported * Operating the peripheral in slave mode without first specifying and address using i2c_slave_address * Setting an address using i2c_slave_address after initialising the peripheral in master mode * Setting an address to an `I2C` reserved value * Specifying an invalid address when calling any `read` or `write` functions * Setting the length of the transfer or receive buffers to larger than the buffers are * Passing an invalid pointer as `handler` * Calling i2c_abort_async when no transfer is currently in progress

Function Documentation