i2cspm.c

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/***************************************************************************/
#include <stddef.h>
#include "em_cmu.h"
#include "em_gpio.h"
#include "i2cspmconfig.h"
#include "i2cspm.h"
#include "em_assert.h"

/*******************************************************************************
 **************************   GLOBAL FUNCTIONS   *******************************
 ******************************************************************************/

/***************************************************************************/
void I2CSPM_Init(I2CSPM_Init_TypeDef *init)
{
  int i;
  CMU_Clock_TypeDef i2cClock;
  I2C_Init_TypeDef i2cInit;

  EFM_ASSERT(init != NULL);

  CMU_ClockEnable(cmuClock_HFPER, true);

  /* Select I2C peripheral clock */
  if (false)
  {
#if defined( I2C0 )
  }
  else if (init->port == I2C0)
  {
    i2cClock = cmuClock_I2C0;
#endif
#if defined( I2C1 )
  }
  else if (init->port == I2C1)
  {
    i2cClock = cmuClock_I2C1;
#endif
  }
  else
  {
    /* I2C clock is not defined */
    EFM_ASSERT(false);
    return;
  }
  CMU_ClockEnable(i2cClock, true);

  /* Output value must be set to 1 to not drive lines low. Set
     SCL first, to ensure it is high before changing SDA. */
  GPIO_PinModeSet(init->sclPort, init->sclPin, gpioModeWiredAndPullUp, 1);
  GPIO_PinModeSet(init->sdaPort, init->sdaPin, gpioModeWiredAndPullUp, 1);

  /* In some situations, after a reset during an I2C transfer, the slave
     device may be left in an unknown state. Send 9 clock pulses to
     set slave in a defined state. */
  for (i = 0; i < 9; i++)
  {
    GPIO_PinOutSet(init->sclPort, init->sclPin);
    GPIO_PinOutClear(init->sclPort, init->sclPin);
  }

  /* Enable pins and set location */
#if defined (_I2C_ROUTEPEN_MASK)
  init->port->ROUTEPEN  = I2C_ROUTEPEN_SDAPEN | I2C_ROUTEPEN_SCLPEN;
  init->port->ROUTELOC0 = (init->portLocationSda << _I2C_ROUTELOC0_SDALOC_SHIFT)
                          | (init->portLocationScl << _I2C_ROUTELOC0_SCLLOC_SHIFT);
#else
  init->port->ROUTE = I2C_ROUTE_SDAPEN |
                      I2C_ROUTE_SCLPEN |
                      (init->portLocation << _I2C_ROUTE_LOCATION_SHIFT);
#endif

  /* Set emlib init parameters */
  i2cInit.enable = true;
  i2cInit.master = true; /* master mode only */
  i2cInit.freq = init->i2cMaxFreq;
  i2cInit.refFreq = init->i2cRefFreq;
  i2cInit.clhr = init->i2cClhr;

  I2C_Init(init->port, &i2cInit);
}


/***************************************************************************/
I2C_TransferReturn_TypeDef I2CSPM_Transfer(I2C_TypeDef *i2c, I2C_TransferSeq_TypeDef *seq)
{
  I2C_TransferReturn_TypeDef ret;
  uint32_t timeout = I2CSPM_TRANSFER_TIMEOUT;
  /* Do a polled transfer */
  ret = I2C_TransferInit(i2c, seq);
  while (ret == i2cTransferInProgress && timeout--)
  {
    ret = I2C_Transfer(i2c);
  }
  return ret;
}