static void
i2c_init(uint32_t bus, SercomI2cm *si)
{
static uint8_t have_run_init;
if (have_run_init & (1<<bus))
return;
have_run_init |= 1<<bus;
// Configure i2c
si->CTRLA.reg = 0;
uint32_t areg = (SERCOM_I2CM_CTRLA_LOWTOUTEN
| SERCOM_I2CM_CTRLA_INACTOUT(3)
| SERCOM_I2CM_STATUS_SEXTTOUT
| SERCOM_I2CM_STATUS_MEXTTOUT
| SERCOM_I2CM_CTRLA_MODE(5));
si->CTRLA.reg = areg;
uint32_t freq = sercom_get_pclock_frequency(bus);
uint32_t baud = (freq/I2C_FREQ - 10 - freq*TIME_RISE/1000000000) / 2;
si->BAUD.reg = baud;
si->CTRLA.reg = areg | SERCOM_I2CM_CTRLA_ENABLE;
while (si->SYNCBUSY.reg & SERCOM_I2CM_SYNCBUSY_ENABLE)
;
// Go into idle mode
si->STATUS.reg = SERCOM_I2CM_STATUS_BUSSTATE(1);
while (si->SYNCBUSY.reg & SERCOM_I2CM_SYNCBUSY_SYSOP)
;
}
void SERCOM::initMasterWIRE( uint32_t baudrate )
{
// Initialize the peripheral clock and interruption
initClockNVIC() ;
resetWIRE() ;
// Set master mode and enable SCL Clock Stretch mode (stretch after ACK bit)
sercom->I2CM.CTRLA.reg = SERCOM_I2CM_CTRLA_MODE( I2C_MASTER_OPERATION )/* |
SERCOM_I2CM_CTRLA_SCLSM*/ ;
// Enable Smart mode and Quick Command
//sercom->I2CM.CTRLB.reg = SERCOM_I2CM_CTRLB_SMEN /*| SERCOM_I2CM_CTRLB_QCEN*/ ;
// Enable all interrupts
// sercom->I2CM.INTENSET.reg = SERCOM_I2CM_INTENSET_MB | SERCOM_I2CM_INTENSET_SB | SERCOM_I2CM_INTENSET_ERROR ;
// Synchronous arithmetic baudrate
sercom->I2CM.BAUD.bit.BAUD = SystemCoreClock / ( 2 * baudrate) - 1 ;
}
/**
* \brief Initializes the requested I<SUP>2</SUP>C hardware module
*
* Initializes the SERCOM I<SUP>2</SUP>C master 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
* \retval STATUS_ERR_BAUDRATE_UNAVAILABLE If given baudrate is not compatible
* with set GCLK frequency
*
*/
enum status_code i2c_master_init(
struct i2c_master_module *const module,
Sercom *const hw,
const struct i2c_master_config *const config)
{
/* Sanity check arguments. */
Assert(module);
Assert(hw);
Assert(config);
/* Initialize software module */
module->hw = hw;
SercomI2cm *const i2c_module = &(module->hw->I2CM);
uint32_t sercom_index = _sercom_get_sercom_inst_index(module->hw);
#if (SAML21)
uint32_t pm_index = sercom_index + MCLK_APBCMASK_SERCOM0_Pos;
#else
uint32_t pm_index = sercom_index + PM_APBCMASK_SERCOM0_Pos;
#endif
uint32_t gclk_index = sercom_index + SERCOM0_GCLK_ID_CORE;
/* Turn on module in PM */
system_apb_clock_set_mask(SYSTEM_CLOCK_APB_APBC, 1 << pm_index);
/* 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);
/* Check if module is enabled. */
if (i2c_module->CTRLA.reg & SERCOM_I2CM_CTRLA_ENABLE) {
return STATUS_ERR_DENIED;
}
/* Check if reset is in progress. */
if (i2c_module->CTRLA.reg & SERCOM_I2CM_CTRLA_SWRST) {
return STATUS_BUSY;
}
#if I2C_MASTER_CALLBACK_MODE == true
/* Get sercom instance index and register callback. */
uint8_t instance_index = _sercom_get_sercom_inst_index(module->hw);
_sercom_set_handler(instance_index, _i2c_master_interrupt_handler);
_sercom_instances[instance_index] = module;
/* Initialize values in module. */
module->registered_callback = 0;
module->enabled_callback = 0;
module->buffer_length = 0;
module->buffer_remaining = 0;
module->status = STATUS_OK;
module->buffer = NULL;
#endif
/* Set sercom module to operate in I2C master mode. */
i2c_module->CTRLA.reg = SERCOM_I2CM_CTRLA_MODE(0x5);
/* Set config and return status. */
return _i2c_master_set_config(module, config);
}
