/**
* \brief Initialize TWIHS slave mode.
*
* \param p_twihs Pointer to a TWIHS instance.
* \param ul_device_addr Device address of the SAM slave device on the I2C bus.
*/
void twihs_slave_init(Twihs *p_twihs, uint32_t ul_device_addr)
{
/* Disable TWIHS interrupts */
p_twihs->TWIHS_IDR = ~0UL;
p_twihs->TWIHS_SR;
/* Reset TWIHS */
twihs_reset(p_twihs);
/* Set slave address in slave mode */
p_twihs->TWIHS_SMR = TWIHS_SMR_SADR(ul_device_addr);
/* Enable slave mode */
twihs_enable_slave_mode(p_twihs);
}
/**
* \brief Initialize TWIHS master mode.
*
* \param p_twihs Pointer to a TWIHS instance.
* \param p_opt Options for initializing the TWIHS module (see \ref twihs_options_t).
*
* \return TWIHS_SUCCESS if initialization is complete, error code otherwise.
*/
uint32_t twihs_master_init(Twihs *p_twihs, const twihs_options_t *p_opt)
{
uint32_t status = TWIHS_SUCCESS;
/* Disable TWIHS interrupts */
p_twihs->TWIHS_IDR = ~0UL;
/* Dummy read in status register */
p_twihs->TWIHS_SR;
/* Reset TWIHS peripheral */
twihs_reset(p_twihs);
twihs_enable_master_mode(p_twihs);
/* Select the speed */
if (twihs_set_speed(p_twihs, p_opt->speed, p_opt->master_clk) == FAIL) {
/* The desired speed setting is rejected */
status = TWIHS_INVALID_ARGUMENT;
}
return status;
}
/**
* \ingroup freertos_twihs_peripheral_control_group
* \brief Initializes the FreeRTOS ASF TWIHS (I2C) master driver for the specified
* TWIHS port.
*
* freertos_twihs_master_init() is an ASF specific FreeRTOS driver function. It
* must be called before any other ASF specific FreeRTOS driver functions
* attempt to access the same TWIHS port.
*
* If freertos_driver_parameters->operation_mode equals TWIHS_I2C_MASTER then
* freertos_twihs_master_init() will configure the TWIHS port for master mode
* operation and enable the peripheral. If
* freertos_driver_parameters->operation_mode equals any other value then
* freertos_twihs_master_init() will not take any action.
*
* Other ASF TWIHS functions can be called after freertos_twihs_master_init() has
* completed successfully.
*
* The FreeRTOS ASF driver both installs and handles the TWIHS PDC interrupts.
* Users do not need to concern themselves with interrupt handling, and must
* not install their own interrupt handler.
*
* This driver is provided with an application note, and an example project that
* demonstrates the use of this function.
*
* \param p_twihs The twihs peripheral being initialized.
* \param freertos_driver_parameters Defines the driver behavior. See the
* freertos_peripheral_options_t documentation, and the application note that
* accompanies the ASF specific FreeRTOS functions.
*
* \return If the initialization completes successfully then a handle that can
* be used with FreeRTOS TWIHS read and write functions is returned. If
* the initialisation fails then NULL is returned.
*/
freertos_twihs_if freertos_twihs_master_init(Twihs *p_twihs,
const freertos_peripheral_options_t *const freertos_driver_parameters)
{
portBASE_TYPE twihs_index;
bool is_valid_operating_mode;
freertos_twihs_if return_value;
const enum peripheral_operation_mode valid_operating_modes[] = {TWIHS_I2C_MASTER};
/* Find the index into the all_twihs_definitions array that holds details of
the p_twihs peripheral. */
twihs_index = get_pdc_peripheral_details(all_twihs_definitions, MAX_TWIHS,
(void *) p_twihs);
/* Check the requested operating mode is valid for the peripheral. */
is_valid_operating_mode = check_requested_operating_mode(
freertos_driver_parameters->operation_mode,
valid_operating_modes,
sizeof(valid_operating_modes) /
sizeof(enum peripheral_operation_mode));
/* Don't do anything unless a valid p_twihs pointer was used, and a valid
operating mode was requested. */
if ((twihs_index < MAX_TWIHS) && (is_valid_operating_mode == true)) {
/* This function must be called exactly once per supported twihs. Check
it has not been called before. */
configASSERT(memcmp((void *)&(tx_dma_control[twihs_index]),
&null_dma_control,
sizeof(null_dma_control)) == 0);
configASSERT(memcmp((void *)&(rx_dma_control[twihs_index]),
&null_dma_control,
sizeof(null_dma_control)) == 0);
/* Enable the peripheral's clock. */
pmc_enable_periph_clk(
all_twihs_definitions[twihs_index].peripheral_id);
/* Ensure everything is disabled before configuration. */
pdc_disable_transfer(
all_twihs_definitions[twihs_index].pdc_base_address,
(PERIPH_PTCR_RXTDIS | PERIPH_PTCR_TXTDIS));
twihs_disable_interrupt(
all_twihs_definitions[twihs_index].peripheral_base_address,
MASK_ALL_INTERRUPTS);
twihs_reset(
all_twihs_definitions[twihs_index].peripheral_base_address);
switch (freertos_driver_parameters->operation_mode) {
case TWIHS_I2C_MASTER:
/* Call the standard ASF init function. */
twihs_enable_master_mode(
all_twihs_definitions[twihs_index].peripheral_base_address);
break;
default:
/* No other modes are currently supported. */
break;
}
/* Create any required peripheral access mutexes and transaction complete
semaphores. This peripheral is half duplex so only a single access
mutex is required. */
create_peripheral_control_semaphores(
freertos_driver_parameters->options_flags,
&(tx_dma_control[twihs_index]),
&(rx_dma_control[twihs_index]));
/* Error interrupts are always enabled. */
twihs_enable_interrupt(
all_twihs_definitions[twihs_index].peripheral_base_address,
IER_ERROR_INTERRUPTS);
/* Configure and enable the TWIHS interrupt in the interrupt controller. */
configure_interrupt_controller(
all_twihs_definitions[twihs_index].peripheral_irq,
freertos_driver_parameters->interrupt_priority);
return_value = (freertos_twihs_if) p_twihs;
} else {
return_value = NULL;
}
return return_value;
}
