/**
* \brief Initializes the requested I<SUP>2</SUP>C hardware module
*
* Initializes the I<SUP>2</SUP>C slave device requested and sets the provided
* software module struct. Run this function before any further use of
* the driver.
*
* \param[out] module Pointer to software module struct
* \param[in] config Pointer to the configuration struct
*
* \return Status of initialization.
* \retval STATUS_OK Module initiated correctly
* \retval STATUS_ERR_INVALID_ARG Invalid argument in module or config structure.
* \retval STATUS_ERR_ALREADY_INITIALIZED If the Pinmux is not a valid one for I2C signals.
*
*/
enum status_code i2c_slave_init(
struct i2c_slave_module *const module,
I2c *const hw,
const struct i2c_slave_config *const config)
{
/* Sanity check */
Assert(module);
Assert(module->hw);
Assert(config);
module->hw = hw;
/* Sanity check arguments. */
if ((module == NULL) || (config == NULL))
return STATUS_ERR_INVALID_ARG;
i2c_disable(module->hw);
if (module->hw == I2C0)
system_peripheral_reset(PERIPHERAL_I2C0_CORE);
else if (module->hw == I2C1) {
system_peripheral_reset(PERIPHERAL_I2C1_CORE);
} else {
return STATUS_ERR_INVALID_ARG;
}
#if I2C_SLAVE_CALLBACK_MODE == true
/* Initialize values in module. */
module->registered_callback = 0;
module->enabled_callback = 0;
module->buffer_length = 0;
module->buffer_remaining = 0;
module->buffer = NULL;
module->status = STATUS_OK;
_i2c_instances = (void*)module;
if (module->hw == I2C0) {
system_register_isr(RAM_ISR_TABLE_I2CRX0_INDEX, (uint32_t)_i2c_slave_rx_isr_handler);
system_register_isr(RAM_ISR_TABLE_I2CTX0_INDEX, (uint32_t)_i2c_slave_tx_isr_handler);
NVIC_EnableIRQ(I2C0_RX_IRQn);
NVIC_EnableIRQ(I2C0_TX_IRQn);
} else if (module->hw == I2C1) {
system_register_isr(RAM_ISR_TABLE_I2CRX1_INDEX, (uint32_t)_i2c_slave_rx_isr_handler);
system_register_isr(RAM_ISR_TABLE_I2CTX1_INDEX, (uint32_t)_i2c_slave_tx_isr_handler);
NVIC_EnableIRQ(I2C1_RX_IRQn);
NVIC_EnableIRQ(I2C1_TX_IRQn);
}
#endif
/* Set config and return status. */
if(_i2c_slave_set_config(module, config) != STATUS_OK)
return STATUS_ERR_NOT_INITIALIZED;
return STATUS_OK;
}
/**
* \brief Initializes the requested I<SUP>2</SUP>C hardware module
*
* Initializes the SERCOM I<SUP>2</SUP>C slave device requested and sets the provided
* software module struct. Run this function before any further use of
* the driver.
*
* \param[out] module Pointer to software module struct
* \param[in] hw Pointer to the hardware instance
* \param[in] config Pointer to the configuration struct
*
* \return Status of initialization.
* \retval STATUS_OK Module initiated correctly
* \retval STATUS_ERR_DENIED If module is enabled
* \retval STATUS_BUSY If module is busy resetting
* \retval STATUS_ERR_ALREADY_INITIALIZED If setting other GCLK generator than
* previously set
*/
enum status_code i2c_slave_init(
struct i2c_slave_module *const module,
Sercom *const hw,
const struct i2c_slave_config *const config)
{
/* Sanity check arguments */
Assert(module);
Assert(hw);
Assert(config);
/* Initialize software module */
module->hw = hw;
SercomI2cs *const i2c_hw = &(module->hw->I2CS);
/* Check if module is enabled */
if (i2c_hw->CTRLA.reg & SERCOM_I2CS_CTRLA_ENABLE) {
return STATUS_ERR_DENIED;
}
/* Check if reset is in progress */
if (i2c_hw->CTRLA.reg & SERCOM_I2CS_CTRLA_SWRST) {
return STATUS_BUSY;
}
uint32_t sercom_index = _sercom_get_sercom_inst_index(module->hw);
uint32_t pm_index, gclk_index;
#if (SAML21) || (SAML22) || (SAMC20) || (SAMC21)
#if (SAML21)
if (sercom_index == 5) {
pm_index = MCLK_APBDMASK_SERCOM5_Pos;
gclk_index = SERCOM5_GCLK_ID_CORE;
} else {
pm_index = sercom_index + MCLK_APBCMASK_SERCOM0_Pos;
gclk_index = sercom_index + SERCOM0_GCLK_ID_CORE;
}
#else
pm_index = sercom_index + MCLK_APBCMASK_SERCOM0_Pos;
gclk_index = sercom_index + SERCOM0_GCLK_ID_CORE;
#endif
#else
pm_index = sercom_index + PM_APBCMASK_SERCOM0_Pos;
gclk_index = sercom_index + SERCOM0_GCLK_ID_CORE;
#endif
/* Turn on module in PM */
#if (SAML21)
if (sercom_index == 5) {
system_apb_clock_set_mask(SYSTEM_CLOCK_APB_APBD, 1 << pm_index);
} else {
system_apb_clock_set_mask(SYSTEM_CLOCK_APB_APBC, 1 << pm_index);
}
#else
system_apb_clock_set_mask(SYSTEM_CLOCK_APB_APBC, 1 << pm_index);
#endif
/* Set up the GCLK for the module */
struct system_gclk_chan_config gclk_chan_conf;
system_gclk_chan_get_config_defaults(&gclk_chan_conf);
gclk_chan_conf.source_generator = config->generator_source;
system_gclk_chan_set_config(gclk_index, &gclk_chan_conf);
system_gclk_chan_enable(gclk_index);
sercom_set_gclk_generator(config->generator_source, false);
#if I2C_SLAVE_CALLBACK_MODE == true
/* Get sercom instance index */
uint8_t instance_index = _sercom_get_sercom_inst_index(module->hw);
/* Save software module in interrupt handler */
_sercom_set_handler(instance_index, _i2c_slave_interrupt_handler);
/* Save software module */
_sercom_instances[instance_index] = module;
/* Initialize values in module */
module->registered_callback = 0;
module->enabled_callback = 0;
module->buffer_length = 0;
module->nack_on_address = config->enable_nack_on_address;
#endif
/* Set SERCOM module to operate in I2C slave mode */
i2c_hw->CTRLA.reg = SERCOM_I2CS_CTRLA_MODE(0x4);
/* Set config and return status */
return _i2c_slave_set_config(module, config);
}