tinySA/os/hal/platforms/LPC13xx/gpt_lld.c

/*
    ChibiOS/RT - Copyright (C) 2006,2007,2008,2009,2010 Giovanni Di Sirio.

    This file is part of ChibiOS/RT.

    ChibiOS/RT is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation; either version 3 of the License, or
    (at your option) any later version.

    ChibiOS/RT is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program.  If not, see <http://www.gnu.org/licenses/>.
*/

/**
 * @file    LPC13xx/gpt_lld.c
 * @brief   LPC13xx GPT subsystem low level driver source.
 *
 * @addtogroup GPT
 * @{
 */

#include "ch.h"
#include "hal.h"

#if HAL_USE_GPT || defined(__DOXYGEN__)

/*===========================================================================*/
/* Driver exported variables.                                                */
/*===========================================================================*/

/**
 * @brief   GPT1 driver identifier.
 * @note    The driver GPT1 allocates the complex timer CT16B0 when enabled.
 */
#if LPC13xx_GPT_USE_CT16B0 || defined(__DOXYGEN__)
GPTDriver GPTD1;
#endif

/**
 * @brief   GPT2 driver identifier.
 * @note    The driver GPT2 allocates the timer CT16B1 when enabled.
 */
#if LPC13xx_GPT_USE_CT16B1 || defined(__DOXYGEN__)
GPTDriver GPTD2;
#endif

/**
 * @brief   GPT3 driver identifier.
 * @note    The driver GPT3 allocates the timer CT32B0 when enabled.
 */
#if LPC13xx_GPT_USE_CT32B0 || defined(__DOXYGEN__)
GPTDriver GPTD3;
#endif

/**
 * @brief   GPT4 driver identifier.
 * @note    The driver GPT4 allocates the timer CT32B1 when enabled.
 */
#if LPC13xx_GPT_USE_CT32B1 || defined(__DOXYGEN__)
GPTDriver GPTD4;
#endif

/*===========================================================================*/
/* Driver local variables.                                                   */
/*===========================================================================*/

/*===========================================================================*/
/* Driver local functions.                                                   */
/*===========================================================================*/

/**
 * @brief   Shared IRQ handler.
 *
 * @param[in] gptp      pointer to a @p GPTDriver object
 */
static void gpt_lld_serve_interrupt(GPTDriver *gptp) {

  gptp->tmr->IR = 1;                        /* Clear interrupt on match MR0.*/
  if (gptp->state == GPT_ONESHOT) {
    gptp->state = GPT_READY;                /* Back in GPT_READY state.     */
    gpt_lld_stop_timer(gptp);               /* Timer automatically stopped. */
  }
  gptp->config->callback(gptp);
}

/*===========================================================================*/
/* Driver interrupt handlers.                                                */
/*===========================================================================*/

#if LPC13xx_GPT_USE_CT16B0
/**
 * @brief   CT16B0 interrupt handler.
 *
 * @isr
 */
CH_IRQ_HANDLER(VectorE4) {

  CH_IRQ_PROLOGUE();

  gpt_lld_serve_interrupt(&GPTD1);

  CH_IRQ_EPILOGUE();
}
#endif /* LPC13xx_GPT_USE_CT16B0 */

#if LPC13xx_GPT_USE_CT16B1
/**
 * @brief   CT16B1 interrupt handler.
 *
 * @isr
 */
CH_IRQ_HANDLER(VectorE8) {

  CH_IRQ_PROLOGUE();

  gpt_lld_serve_interrupt(&GPTD2);

  CH_IRQ_EPILOGUE();
}
#endif /* LPC13xx_GPT_USE_CT16B0 */

#if LPC13xx_GPT_USE_CT32B0
/**
 * @brief   CT32B0 interrupt handler.
 *
 * @isr
 */
CH_IRQ_HANDLER(VectorEC) {

  CH_IRQ_PROLOGUE();

  gpt_lld_serve_interrupt(&GPTD3);

  CH_IRQ_EPILOGUE();
}
#endif /* LPC13xx_GPT_USE_CT32B0 */

#if LPC13xx_GPT_USE_CT32B1
/**
 * @brief   CT32B1 interrupt handler.
 *
 * @isr
 */
CH_IRQ_HANDLER(VectorF0) {

  CH_IRQ_PROLOGUE();

  gpt_lld_serve_interrupt(&GPTD4);

  CH_IRQ_EPILOGUE();
}
#endif /* LPC13xx_GPT_USE_CT32B1 */

/*===========================================================================*/
/* Driver exported functions.                                                */
/*===========================================================================*/

/**
 * @brief   Low level GPT driver initialization.
 *
 * @notapi
 */
void gpt_lld_init(void) {

#if LPC13xx_GPT_USE_CT16B0
  /* Driver initialization.*/
  GPTD1.tmr = LPC_TMR16B0;
  gptObjectInit(&GPTD1);
#endif

#if LPC13xx_GPT_USE_CT16B1
  /* Driver initialization.*/
  GPTD2.tmr = LPC_TMR16B1;
  gptObjectInit(&GPTD2);
#endif

#if LPC13xx_GPT_USE_CT32B0
  /* Driver initialization.*/
  GPTD3.tmr = LPC_TMR32B0;
  gptObjectInit(&GPTD3);
#endif

#if LPC13xx_GPT_USE_CT32B1
  /* Driver initialization.*/
  GPTD4.tmr = LPC_TMR32B1;
  gptObjectInit(&GPTD4);
#endif
}

/**
 * @brief   Configures and activates the GPT peripheral.
 *
 * @param[in] gptp      pointer to the @p GPTDriver object
 *
 * @notapi
 */
void gpt_lld_start(GPTDriver *gptp) {
  uint32_t pr;

  if (gptp->state == GPT_STOP) {
    /* Clock activation.*/
#if LPC13xx_GPT_USE_CT16B0
    if (&GPTD1 == gptp) {
      LPC_SYSCON->SYSAHBCLKCTRL |= (1 << 7);
      NVICEnableVector(TIMER_16_0_IRQn, CORTEX_PRIORITY_MASK(2));
    }
#endif
#if LPC13xx_GPT_USE_CT16B1
    if (&GPTD2 == gptp) {
      LPC_SYSCON->SYSAHBCLKCTRL |= (1 << 8);
      NVICEnableVector(TIMER_16_1_IRQn, CORTEX_PRIORITY_MASK(3));
    }
#endif
#if LPC13xx_GPT_USE_CT32B0
    if (&GPTD3 == gptp) {
      LPC_SYSCON->SYSAHBCLKCTRL |= (1 << 9);
      NVICEnableVector(TIMER_32_0_IRQn, CORTEX_PRIORITY_MASK(2));
    }
#endif
#if LPC13xx_GPT_USE_CT32B1
    if (&GPTD4 == gptp) {
      LPC_SYSCON->SYSAHBCLKCTRL |= (1 << 10);
      NVICEnableVector(TIMER_32_1_IRQn, CORTEX_PRIORITY_MASK(2));
    }
#endif
  }

  /* Prescaler value calculation.*/
  pr = (uint16_t)((LPC13xx_SYSCLK / gptp->config->frequency) - 1);
  chDbgAssert(((uint32_t)(pr + 1) * gptp->config->frequency) == LPC13xx_SYSCLK,
              "gpt_lld_start(), #1", "invalid frequency");

  /* Timer configuration.*/
  gptp->tmr->PR  = pr;
  gptp->tmr->IR  = 1;
  gptp->tmr->MCR = 0;
  gptp->tmr->TCR = 0;
}

/**
 * @brief   Deactivates the GPT peripheral.
 *
 * @param[in] gptp      pointer to the @p GPTDriver object
 *
 * @notapi
 */
void gpt_lld_stop(GPTDriver *gptp) {

  if (gptp->state == GPT_READY) {
    gptp->tmr->MCR = 0;
    gptp->tmr->TCR = 0;

#if LPC13xx_GPT_USE_CT16B0
    if (&GPTD1 == gptp) {
      NVICDisableVector(TIMER_16_0_IRQn);
      LPC_SYSCON->SYSAHBCLKCTRL &= ~(1 << 7);
    }
#endif
#if LPC13xx_GPT_USE_CT16B1
    if (&GPTD2 == gptp) {
      NVICDisableVector(TIMER_16_1_IRQn);
      LPC_SYSCON->SYSAHBCLKCTRL &= ~(1 << 8);
    }
#endif
#if LPC13xx_GPT_USE_CT32B0
    if (&GPTD3 == gptp) {
      NVICDisableVector(TIMER_32_0_IRQn);
      LPC_SYSCON->SYSAHBCLKCTRL &= ~(1 << 9);
    }
#endif
#if LPC13xx_GPT_USE_CT32B1
    if (&GPTD4 == gptp) {
      NVICDisableVector(TIMER_32_1_IRQn);
      LPC_SYSCON->SYSAHBCLKCTRL &= ~(1 << 10);
    }
#endif
  }
}

/**
 * @brief   Starts the timer in continuous mode.
 *
 * @param[in] gptp      pointer to the @p GPTDriver object
 * @param[in] interval  period in ticks
 *
 * @notapi
 */
void gpt_lld_start_timer(GPTDriver *gptp, gptcnt_t interval) {

  gptp->tmr->MR0 = interval - 1;
  gptp->tmr->IR  = 1;
  gptp->tmr->MCR = 3;                       /* IRQ and clr TC on match MR0. */
  gptp->tmr->TCR = 2;                       /* Reset counter and prescaler. */
  gptp->tmr->TCR = 1;                       /* Timer enabled.               */
}

/**
 * @brief   Stops the timer.
 *
 * @param[in] gptp      pointer to the @p GPTDriver object
 *
 * @notapi
 */
void gpt_lld_stop_timer(GPTDriver *gptp) {

  gptp->tmr->IR  = 1;
  gptp->tmr->MCR = 0;
  gptp->tmr->TCR = 0;
}

/**
 * @brief   Starts the timer in one shot mode and waits for completion.
 * @details This function specifically polls the timer waiting for completion
 *          in order to not have extra delays caused by interrupt servicing,
 *          this function is only recommended for short delays.
 *
 * @param[in] gptp      pointer to the @p GPTDriver object
 * @param[in] interval  time interval in ticks
 *
 * @notapi
 */
void gpt_lld_polled_delay(GPTDriver *gptp, gptcnt_t interval) {

  gptp->tmr->MR0 = interval - 1;
  gptp->tmr->IR  = 1;
  gptp->tmr->MCR = 4;                       /* Stop TC on match MR0.        */
  gptp->tmr->TCR = 2;                       /* Reset counter and prescaler. */
  gptp->tmr->TCR = 1;                       /* Timer enabled.               */
  while (gptp->tmr->TCR & 1)
    ;
}

#endif /* HAL_USE_GPT */

/** @} */