tinySA/os/hal/platforms/STM32/pwm_lld.c

/*
    ChibiOS/RT - Copyright (C) 2006,2007,2008,2009,2010,
                 2011,2012,2013 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    STM32/pwm_lld.c
 * @brief   STM32 PWM subsystem low level driver header.
 *
 * @addtogroup PWM
 * @{
 */

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

#if HAL_USE_PWM || defined(__DOXYGEN__)

/*===========================================================================*/
/* Driver local definitions.                                                 */
/*===========================================================================*/

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

/**
 * @brief   PWMD1 driver identifier.
 * @note    The driver PWMD1 allocates the complex timer TIM1 when enabled.
 */
#if STM32_PWM_USE_TIM1 || defined(__DOXYGEN__)
PWMDriver PWMD1;
#endif

/**
 * @brief   PWMD2 driver identifier.
 * @note    The driver PWMD2 allocates the timer TIM2 when enabled.
 */
#if STM32_PWM_USE_TIM2 || defined(__DOXYGEN__)
PWMDriver PWMD2;
#endif

/**
 * @brief   PWMD3 driver identifier.
 * @note    The driver PWMD3 allocates the timer TIM3 when enabled.
 */
#if STM32_PWM_USE_TIM3 || defined(__DOXYGEN__)
PWMDriver PWMD3;
#endif

/**
 * @brief   PWMD4 driver identifier.
 * @note    The driver PWMD4 allocates the timer TIM4 when enabled.
 */
#if STM32_PWM_USE_TIM4 || defined(__DOXYGEN__)
PWMDriver PWMD4;
#endif

/**
 * @brief   PWMD5 driver identifier.
 * @note    The driver PWMD5 allocates the timer TIM5 when enabled.
 */
#if STM32_PWM_USE_TIM5 || defined(__DOXYGEN__)
PWMDriver PWMD5;
#endif

/**
 * @brief   PWMD8 driver identifier.
 * @note    The driver PWMD5 allocates the timer TIM5 when enabled.
 */
#if STM32_PWM_USE_TIM8 || defined(__DOXYGEN__)
PWMDriver PWMD8;
#endif

/*===========================================================================*/
/* Driver local variables and types.                                         */
/*===========================================================================*/

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

#if STM32_PWM_USE_TIM2 || STM32_PWM_USE_TIM3 || STM32_PWM_USE_TIM4 ||       \
    STM32_PWM_USE_TIM5 || defined(__DOXYGEN__)
/**
 * @brief   Common TIM2...TIM5 IRQ handler.
 * @note    It is assumed that the various sources are only activated if the
 *          associated callback pointer is not equal to @p NULL in order to not
 *          perform an extra check in a potentially critical interrupt handler.
 *
 * @param[in] pwmp      pointer to a @p PWMDriver object
 */
static void pwm_lld_serve_interrupt(PWMDriver *pwmp) {
  uint16_t sr;

  sr  = pwmp->tim->SR;
  sr &= pwmp->tim->DIER;
  pwmp->tim->SR = ~sr;
  if ((sr & TIM_SR_CC1IF) != 0)
    pwmp->config->channels[0].callback(pwmp);
  if ((sr & TIM_SR_CC2IF) != 0)
    pwmp->config->channels[1].callback(pwmp);
  if ((sr & TIM_SR_CC3IF) != 0)
    pwmp->config->channels[2].callback(pwmp);
  if ((sr & TIM_SR_CC4IF) != 0)
    pwmp->config->channels[3].callback(pwmp);
  if ((sr & TIM_SR_UIF) != 0)
    pwmp->config->callback(pwmp);
}
#endif /* STM32_PWM_USE_TIM2 || ... || STM32_PWM_USE_TIM5 */

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

#if STM32_PWM_USE_TIM1
#if !defined(STM32_TIM1_UP_HANDLER)
#error "STM32_TIM1_UP_HANDLER not defined"
#endif
/**
 * @brief   TIM1 update interrupt handler.
 * @note    It is assumed that this interrupt is only activated if the callback
 *          pointer is not equal to @p NULL in order to not perform an extra
 *          check in a potentially critical interrupt handler.
 *
 * @isr
 */
CH_IRQ_HANDLER(STM32_TIM1_UP_HANDLER) {

  CH_IRQ_PROLOGUE();

  STM32_TIM1->SR = ~TIM_SR_UIF;
  PWMD1.config->callback(&PWMD1);

  CH_IRQ_EPILOGUE();
}

#if !defined(STM32_TIM1_CC_HANDLER)
#error "STM32_TIM1_CC_HANDLER not defined"
#endif
/**
 * @brief   TIM1 compare interrupt handler.
 * @note    It is assumed that the various sources are only activated if the
 *          associated callback pointer is not equal to @p NULL in order to not
 *          perform an extra check in a potentially critical interrupt handler.
 *
 * @isr
 */
CH_IRQ_HANDLER(STM32_TIM1_CC_HANDLER) {
  uint16_t sr;

  CH_IRQ_PROLOGUE();

  sr = STM32_TIM1->SR & STM32_TIM1->DIER;
  STM32_TIM1->SR = ~(TIM_SR_CC1IF | TIM_SR_CC2IF |
                     TIM_SR_CC3IF | TIM_SR_CC4IF);
  if ((sr & TIM_SR_CC1IF) != 0)
    PWMD1.config->channels[0].callback(&PWMD1);
  if ((sr & TIM_SR_CC2IF) != 0)
    PWMD1.config->channels[1].callback(&PWMD1);
  if ((sr & TIM_SR_CC3IF) != 0)
    PWMD1.config->channels[2].callback(&PWMD1);
  if ((sr & TIM_SR_CC4IF) != 0)
    PWMD1.config->channels[3].callback(&PWMD1);

  CH_IRQ_EPILOGUE();
}
#endif /* STM32_PWM_USE_TIM1 */

#if STM32_PWM_USE_TIM2
#if !defined(STM32_TIM2_HANDLER)
#error "STM32_TIM2_HANDLER not defined"
#endif
/**
 * @brief   TIM2 interrupt handler.
 *
 * @isr
 */
CH_IRQ_HANDLER(STM32_TIM2_HANDLER) {

  CH_IRQ_PROLOGUE();

  pwm_lld_serve_interrupt(&PWMD2);

  CH_IRQ_EPILOGUE();
}
#endif /* STM32_PWM_USE_TIM2 */

#if STM32_PWM_USE_TIM3
#if !defined(STM32_TIM3_HANDLER)
#error "STM32_TIM3_HANDLER not defined"
#endif
/**
 * @brief   TIM3 interrupt handler.
 *
 * @isr
 */
CH_IRQ_HANDLER(STM32_TIM3_HANDLER) {

  CH_IRQ_PROLOGUE();

  pwm_lld_serve_interrupt(&PWMD3);

  CH_IRQ_EPILOGUE();
}
#endif /* STM32_PWM_USE_TIM3 */

#if STM32_PWM_USE_TIM4
#if !defined(STM32_TIM4_HANDLER)
#error "STM32_TIM4_HANDLER not defined"
#endif
/**
 * @brief   TIM4 interrupt handler.
 *
 * @isr
 */
CH_IRQ_HANDLER(STM32_TIM4_HANDLER) {

  CH_IRQ_PROLOGUE();

  pwm_lld_serve_interrupt(&PWMD4);

  CH_IRQ_EPILOGUE();
}
#endif /* STM32_PWM_USE_TIM4 */

#if STM32_PWM_USE_TIM5
#if !defined(STM32_TIM5_HANDLER)
#error "STM32_TIM5_HANDLER not defined"
#endif
/**
 * @brief   TIM5 interrupt handler.
 *
 * @isr
 */
CH_IRQ_HANDLER(STM32_TIM5_HANDLER) {

  CH_IRQ_PROLOGUE();

  pwm_lld_serve_interrupt(&PWMD5);

  CH_IRQ_EPILOGUE();
}
#endif /* STM32_PWM_USE_TIM5 */

#if STM32_PWM_USE_TIM8
#if !defined(STM32_TIM8_UP_HANDLER)
#error "STM32_TIM8_UP_HANDLER not defined"
#endif
/**
 * @brief   TIM8 update interrupt handler.
 * @note    It is assumed that this interrupt is only activated if the callback
 *          pointer is not equal to @p NULL in order to not perform an extra
 *          check in a potentially critical interrupt handler.
 *
 * @isr
 */
CH_IRQ_HANDLER(STM32_TIM8_UP_HANDLER) {

  CH_IRQ_PROLOGUE();

  STM32_TIM8->SR = ~TIM_SR_UIF;
  PWMD8.config->callback(&PWMD8);

  CH_IRQ_EPILOGUE();
}

#if !defined(STM32_TIM8_CC_HANDLER)
#error "STM32_TIM8_CC_HANDLER not defined"
#endif
/**
 * @brief   TIM8 compare interrupt handler.
 * @note    It is assumed that the various sources are only activated if the
 *          associated callback pointer is not equal to @p NULL in order to not
 *          perform an extra check in a potentially critical interrupt handler.
 *
 * @isr
 */
CH_IRQ_HANDLER(STM32_TIM8_CC_HANDLER) {
  uint16_t sr;

  CH_IRQ_PROLOGUE();

  sr = STM32_TIM8->SR & STM32_TIM8->DIER;
  STM32_TIM8->SR = ~(TIM_SR_CC1IF | TIM_SR_CC2IF |
                     TIM_SR_CC3IF | TIM_SR_CC4IF);
  if ((sr & TIM_SR_CC1IF) != 0)
    PWMD8.config->channels[0].callback(&PWMD8);
  if ((sr & TIM_SR_CC2IF) != 0)
    PWMD8.config->channels[1].callback(&PWMD8);
  if ((sr & TIM_SR_CC3IF) != 0)
    PWMD8.config->channels[2].callback(&PWMD8);
  if ((sr & TIM_SR_CC4IF) != 0)
    PWMD8.config->channels[3].callback(&PWMD8);

  CH_IRQ_EPILOGUE();
}
#endif /* STM32_PWM_USE_TIM8 */

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

/**
 * @brief   Low level PWM driver initialization.
 *
 * @notapi
 */
void pwm_lld_init(void) {

#if STM32_PWM_USE_TIM1
  /* Driver initialization.*/
  pwmObjectInit(&PWMD1);
  PWMD1.tim = STM32_TIM1;
#endif

#if STM32_PWM_USE_TIM2
  /* Driver initialization.*/
  pwmObjectInit(&PWMD2);
  PWMD2.tim = STM32_TIM2;
#endif

#if STM32_PWM_USE_TIM3
  /* Driver initialization.*/
  pwmObjectInit(&PWMD3);
  PWMD3.tim = STM32_TIM3;
#endif

#if STM32_PWM_USE_TIM4
  /* Driver initialization.*/
  pwmObjectInit(&PWMD4);
  PWMD4.tim = STM32_TIM4;
#endif

#if STM32_PWM_USE_TIM5
  /* Driver initialization.*/
  pwmObjectInit(&PWMD5);
  PWMD5.tim = STM32_TIM5;
#endif

#if STM32_PWM_USE_TIM8
  /* Driver initialization.*/
  pwmObjectInit(&PWMD8);
  PWMD8.tim = STM32_TIM8;
#endif
}

/**
 * @brief   Configures and activates the PWM peripheral.
 * @note    Starting a driver that is already in the @p PWM_READY state
 *          disables all the active channels.
 *
 * @param[in] pwmp      pointer to a @p PWMDriver object
 *
 * @notapi
 */
void pwm_lld_start(PWMDriver *pwmp) {
  uint32_t psc;
  uint16_t ccer;

  if (pwmp->state == PWM_STOP) {
    /* Clock activation and timer reset.*/
#if STM32_PWM_USE_TIM1
    if (&PWMD1 == pwmp) {
      rccEnableTIM1(FALSE);
      rccResetTIM1();
      nvicEnableVector(STM32_TIM1_UP_NUMBER,
                       CORTEX_PRIORITY_MASK(STM32_PWM_TIM1_IRQ_PRIORITY));
      nvicEnableVector(STM32_TIM1_CC_NUMBER,
                       CORTEX_PRIORITY_MASK(STM32_PWM_TIM1_IRQ_PRIORITY));
      pwmp->clock = STM32_TIMCLK2;
    }
#endif
#if STM32_PWM_USE_TIM2
    if (&PWMD2 == pwmp) {
      rccEnableTIM2(FALSE);
      rccResetTIM2();
      nvicEnableVector(STM32_TIM2_NUMBER,
                       CORTEX_PRIORITY_MASK(STM32_PWM_TIM2_IRQ_PRIORITY));
      pwmp->clock = STM32_TIMCLK1;
    }
#endif
#if STM32_PWM_USE_TIM3
    if (&PWMD3 == pwmp) {
      rccEnableTIM3(FALSE);
      rccResetTIM3();
      nvicEnableVector(STM32_TIM3_NUMBER,
                       CORTEX_PRIORITY_MASK(STM32_PWM_TIM3_IRQ_PRIORITY));
      pwmp->clock = STM32_TIMCLK1;
    }
#endif
#if STM32_PWM_USE_TIM4
    if (&PWMD4 == pwmp) {
      rccEnableTIM4(FALSE);
      rccResetTIM4();
      nvicEnableVector(STM32_TIM4_NUMBER,
                       CORTEX_PRIORITY_MASK(STM32_PWM_TIM4_IRQ_PRIORITY));
      pwmp->clock = STM32_TIMCLK1;
    }
#endif

#if STM32_PWM_USE_TIM5
    if (&PWMD5 == pwmp) {
      rccEnableTIM5(FALSE);
      rccResetTIM5();
      nvicEnableVector(STM32_TIM5_NUMBER,
                       CORTEX_PRIORITY_MASK(STM32_PWM_TIM5_IRQ_PRIORITY));
      pwmp->clock = STM32_TIMCLK1;
    }
#endif
#if STM32_PWM_USE_TIM8
    if (&PWMD8 == pwmp) {
      rccEnableTIM8(FALSE);
      rccResetTIM8();
      nvicEnableVector(STM32_TIM8_UP_NUMBER,
                       CORTEX_PRIORITY_MASK(STM32_PWM_TIM8_IRQ_PRIORITY));
      nvicEnableVector(STM32_TIM8_CC_NUMBER,
                       CORTEX_PRIORITY_MASK(STM32_PWM_TIM8_IRQ_PRIORITY));
      pwmp->clock = STM32_TIMCLK2;
    }
#endif

    /* All channels configured in PWM1 mode with preload enabled and will
       stay that way until the driver is stopped.*/
    pwmp->tim->CCMR1 = TIM_CCMR1_OC1M_1 | TIM_CCMR1_OC1M_2 |
                       TIM_CCMR1_OC1PE |
                       TIM_CCMR1_OC2M_1 | TIM_CCMR1_OC2M_2 |
                       TIM_CCMR1_OC2PE;
    pwmp->tim->CCMR2 = TIM_CCMR2_OC3M_1 | TIM_CCMR2_OC3M_2 |
                       TIM_CCMR2_OC3PE |
                       TIM_CCMR2_OC4M_1 | TIM_CCMR2_OC4M_2 |
                       TIM_CCMR2_OC4PE;
  }
  else {
    /* Driver re-configuration scenario, it must be stopped first.*/
    pwmp->tim->CR1    = 0;                  /* Timer disabled.              */
    pwmp->tim->DIER   = 0;                  /* All IRQs disabled.           */
    pwmp->tim->SR     = 0;                  /* Clear eventual pending IRQs. */
    pwmp->tim->CCR[0] = 0;                  /* Comparator 1 disabled.       */
    pwmp->tim->CCR[1] = 0;                  /* Comparator 2 disabled.       */
    pwmp->tim->CCR[2] = 0;                  /* Comparator 3 disabled.       */
    pwmp->tim->CCR[3] = 0;                  /* Comparator 4 disabled.       */
    pwmp->tim->CNT  = 0;                    /* Counter reset to zero.       */
  }

  /* Timer configuration.*/
  psc = (pwmp->clock / pwmp->config->frequency) - 1;
  chDbgAssert((psc <= 0xFFFF) &&
              ((psc + 1) * pwmp->config->frequency) == pwmp->clock,
              "pwm_lld_start(), #1", "invalid frequency");
  pwmp->tim->PSC  = (uint16_t)psc;
  pwmp->tim->ARR  = (uint16_t)(pwmp->period - 1);
  pwmp->tim->CR2  = pwmp->config->cr2;

  /* Output enables and polarities setup.*/
  ccer = 0;
  switch (pwmp->config->channels[0].mode & PWM_OUTPUT_MASK) {
  case PWM_OUTPUT_ACTIVE_LOW:
    ccer |= TIM_CCER_CC1P;
  case PWM_OUTPUT_ACTIVE_HIGH:
    ccer |= TIM_CCER_CC1E;
  default:
    ;
  }
  switch (pwmp->config->channels[1].mode & PWM_OUTPUT_MASK) {
  case PWM_OUTPUT_ACTIVE_LOW:
    ccer |= TIM_CCER_CC2P;
  case PWM_OUTPUT_ACTIVE_HIGH:
    ccer |= TIM_CCER_CC2E;
  default:
    ;
  }
  switch (pwmp->config->channels[2].mode & PWM_OUTPUT_MASK) {
  case PWM_OUTPUT_ACTIVE_LOW:
    ccer |= TIM_CCER_CC3P;
  case PWM_OUTPUT_ACTIVE_HIGH:
    ccer |= TIM_CCER_CC3E;
  default:
    ;
  }
  switch (pwmp->config->channels[3].mode & PWM_OUTPUT_MASK) {
  case PWM_OUTPUT_ACTIVE_LOW:
    ccer |= TIM_CCER_CC4P;
  case PWM_OUTPUT_ACTIVE_HIGH:
    ccer |= TIM_CCER_CC4E;
  default:
    ;
  }
#if STM32_PWM_USE_ADVANCED
#if STM32_PWM_USE_TIM1 && !STM32_PWM_USE_TIM8
  if (&PWMD1 == pwmp) {
#endif
#if !STM32_PWM_USE_TIM1 && STM32_PWM_USE_TIM8
  if (&PWMD8 == pwmp) {
#endif
#if STM32_PWM_USE_TIM1 && STM32_PWM_USE_TIM8
  if ((&PWMD1 == pwmp) || (&PWMD8 == pwmp)) {
#endif
    switch (pwmp->config->channels[0].mode & PWM_COMPLEMENTARY_OUTPUT_MASK) {
    case PWM_COMPLEMENTARY_OUTPUT_ACTIVE_LOW:
      ccer |= TIM_CCER_CC1NP;
    case PWM_COMPLEMENTARY_OUTPUT_ACTIVE_HIGH:
      ccer |= TIM_CCER_CC1NE;
    default:
      ;
    }
    switch (pwmp->config->channels[1].mode & PWM_COMPLEMENTARY_OUTPUT_MASK) {
    case PWM_COMPLEMENTARY_OUTPUT_ACTIVE_LOW:
      ccer |= TIM_CCER_CC2NP;
    case PWM_COMPLEMENTARY_OUTPUT_ACTIVE_HIGH:
      ccer |= TIM_CCER_CC2NE;
    default:
      ;
    }
    switch (pwmp->config->channels[2].mode & PWM_COMPLEMENTARY_OUTPUT_MASK) {
    case PWM_COMPLEMENTARY_OUTPUT_ACTIVE_LOW:
      ccer |= TIM_CCER_CC3NP;
    case PWM_COMPLEMENTARY_OUTPUT_ACTIVE_HIGH:
      ccer |= TIM_CCER_CC3NE;
    default:
      ;
    }
  }
#endif /* STM32_PWM_USE_ADVANCED*/

  pwmp->tim->CCER = ccer;
  pwmp->tim->EGR  = TIM_EGR_UG;             /* Update event.                */
  pwmp->tim->DIER = pwmp->config->callback == NULL ? 0 : TIM_DIER_UIE;
  pwmp->tim->SR   = 0;                      /* Clear pending IRQs.          */
#if STM32_PWM_USE_TIM1 || STM32_PWM_USE_TIM8
#if STM32_PWM_USE_ADVANCED
  pwmp->tim->BDTR = pwmp->config->bdtr | TIM_BDTR_MOE;
#else
  pwmp->tim->BDTR = TIM_BDTR_MOE;
#endif
#endif
  /* Timer configured and started.*/
  pwmp->tim->CR1  = TIM_CR1_ARPE | TIM_CR1_URS | TIM_CR1_CEN;
}

/**
 * @brief   Deactivates the PWM peripheral.
 *
 * @param[in] pwmp      pointer to a @p PWMDriver object
 *
 * @notapi
 */
void pwm_lld_stop(PWMDriver *pwmp) {

  /* If in ready state then disables the PWM clock.*/
  if (pwmp->state == PWM_READY) {
    pwmp->tim->CR1  = 0;                    /* Timer disabled.              */
    pwmp->tim->DIER = 0;                    /* All IRQs disabled.           */
    pwmp->tim->SR   = 0;                    /* Clear eventual pending IRQs. */
#if STM32_PWM_USE_TIM1 || STM32_PWM_USE_TIM8
    pwmp->tim->BDTR  = 0;
#endif

#if STM32_PWM_USE_TIM1
    if (&PWMD1 == pwmp) {
      nvicDisableVector(STM32_TIM1_UP_NUMBER);
      nvicDisableVector(STM32_TIM1_CC_NUMBER);
      rccDisableTIM1(FALSE);
    }
#endif
#if STM32_PWM_USE_TIM2
    if (&PWMD2 == pwmp) {
      nvicDisableVector(STM32_TIM2_NUMBER);
      rccDisableTIM2(FALSE);
    }
#endif
#if STM32_PWM_USE_TIM3
    if (&PWMD3 == pwmp) {
      nvicDisableVector(STM32_TIM3_NUMBER);
      rccDisableTIM3(FALSE);
    }
#endif
#if STM32_PWM_USE_TIM4
    if (&PWMD4 == pwmp) {
      nvicDisableVector(STM32_TIM4_NUMBER);
      rccDisableTIM4(FALSE);
    }
#endif
#if STM32_PWM_USE_TIM5
    if (&PWMD5 == pwmp) {
      nvicDisableVector(STM32_TIM5_NUMBER);
      rccDisableTIM5(FALSE);
    }
#endif
#if STM32_PWM_USE_TIM8
    if (&PWMD8 == pwmp) {
      nvicDisableVector(STM32_TIM8_UP_NUMBER);
      nvicDisableVector(STM32_TIM8_CC_NUMBER);
      rccDisableTIM8(FALSE);
    }
#endif
  }
}

/**
 * @brief   Enables a PWM channel.
 * @pre     The PWM unit must have been activated using @p pwmStart().
 * @post    The channel is active using the specified configuration.
 * @note    The function has effect at the next cycle start.
 *
 * @param[in] pwmp      pointer to a @p PWMDriver object
 * @param[in] channel   PWM channel identifier (0...PWM_CHANNELS-1)
 * @param[in] width     PWM pulse width as clock pulses number
 *
 * @notapi
 */
void pwm_lld_enable_channel(PWMDriver *pwmp,
                            pwmchannel_t channel,
                            pwmcnt_t width) {

  pwmp->tim->CCR[channel] = width;                  /* New duty cycle.      */
  /* If there is a callback defined for the channel then the associated
     interrupt must be enabled.*/
  if (pwmp->config->channels[channel].callback != NULL) {
    uint32_t dier = pwmp->tim->DIER;
    /* If the IRQ is not already enabled care must be taken to clear it,
       it is probably already pending because the timer is running.*/
    if ((dier & (2 << channel)) == 0) {
      pwmp->tim->DIER = dier | (2 << channel);
      pwmp->tim->SR   = ~(2 << channel);
    }
  }
}

/**
 * @brief   Disables a PWM channel.
 * @pre     The PWM unit must have been activated using @p pwmStart().
 * @post    The channel is disabled and its output line returned to the
 *          idle state.
 * @note    The function has effect at the next cycle start.
 *
 * @param[in] pwmp      pointer to a @p PWMDriver object
 * @param[in] channel   PWM channel identifier (0...PWM_CHANNELS-1)
 *
 * @notapi
 */
void pwm_lld_disable_channel(PWMDriver *pwmp, pwmchannel_t channel) {

  pwmp->tim->CCR[channel] = 0;
  pwmp->tim->DIER &= ~(2 << channel);
}

#endif /* HAL_USE_PWM */

/** @} */