/**
* \brief Set the baudrate of the SPI module
*
* This function will set the baudrate of the SPI module.
*
* \param[in] module Pointer to the software instance struct
* \param[in] baudrate The baudrate wanted
*
* \return The status of the configuration.
* \retval STATUS_ERR_INVALID_ARG If invalid argument(s) were provided
* \retval STATUS_OK If the configuration was written
*/
enum status_code spi_set_baudrate(
struct spi_module *const module,
uint32_t baudrate)
{
/* Sanity check arguments */
Assert(module);
Assert(baudrate);
Assert(module->hw);
/* Value to write to BAUD register */
uint16_t baud = 0;
SercomSpi *const spi_module = &(module->hw->SPI);
/* Disable the module */
spi_disable(module);
while (spi_is_syncing(module)) {
/* Wait until the synchronization is complete */
}
/* Find frequency of the internal SERCOMi_GCLK_ID_CORE */
uint32_t sercom_index = _sercom_get_sercom_inst_index(module->hw);
uint32_t gclk_index = sercom_index + SERCOM0_GCLK_ID_CORE;
uint32_t internal_clock = system_gclk_chan_get_hz(gclk_index);
/* Get baud value, based on baudrate and the internal clock frequency */
enum status_code error_code = _sercom_get_sync_baud_val(
baudrate, internal_clock, &baud);
if (error_code != STATUS_OK) {
/* Baud rate calculation error, return status code */
return STATUS_ERR_INVALID_ARG;
}
spi_module->BAUD.reg = (uint8_t)baud;
while (spi_is_syncing(module)) {
/* Wait until the synchronization is complete */
}
/* Enable the module */
spi_enable(module);
while (spi_is_syncing(module)) {
/* Wait until the synchronization is complete */
}
return STATUS_OK;
}
static inline void spi_disable(spi_t *obj)
{
/* Sanity check arguments */
MBED_ASSERT(obj);
#if DEVICE_SPI_ASYNCH
/* Disable interrupt */
NVIC_DisableIRQ(SERCOM0_IRQn + _sercom_get_sercom_inst_index(pSPI_SERCOM(obj)));
#endif
/* Wait until the synchronization is complete */
while (spi_is_syncing(obj));
/* Disable SPI */
_SPI(obj).CTRLA.reg &= ~SERCOM_SPI_CTRLA_ENABLE;
}
/**
* \brief Resets the SPI module
*
* This function will reset the SPI module to its power on default values and
* disable it.
*
* \param[in,out] module Pointer to the software instance struct
*/
void spi_reset(
struct spi_module *const module)
{
/* Sanity check arguments */
Assert(module);
Assert(module->hw);
SercomSpi *const spi_module = &(module->hw->SPI);
/* Disable the module */
spi_disable(module);
while (spi_is_syncing(module)) {
/* Wait until the synchronization is complete */
}
/* Software reset the module */
spi_module->CTRLA.reg |= SERCOM_SPI_CTRLA_SWRST;
}
