/*
    ChibiOS/RT - Copyright (C) 2006-2013 Giovanni Di Sirio

    Licensed under the Apache License, Version 2.0 (the "License");
    you may not use this file except in compliance with the License.
    You may obtain a copy of the License at

        http://www.apache.org/licenses/LICENSE-2.0

    Unless required by applicable law or agreed to in writing, software
    distributed under the License is distributed on an "AS IS" BASIS,
    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    See the License for the specific language governing permissions and
    limitations under the License.
*/

/**
 * @file    STM32/st_lld.c
 * @brief   ST Driver subsystem low level driver code.
 *
 * @addtogroup ST
 * @{
 */

#include "hal.h"

#if (OSAL_ST_MODE != OSAL_ST_MODE_NONE) || defined(__DOXYGEN__)


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

#if OSAL_ST_MODE == OSAL_ST_MODE_FREERUNNING

#if (OSAL_ST_RESOLUTION == 32)
#define ST_ARR_INIT                         0xFFFFFFFF
#else
#define ST_ARR_INIT                         0x0000FFFF
#endif

#if STM32_ST_USE_TIMER == 2
#if (OSAL_ST_RESOLUTION == 32) && !STM32_TIM2_IS_32BITS
#error "TIM2 is not a 32bits timer"
#endif

#define ST_HANDLER                          STM32_TIM2_HANDLER
#define ST_NUMBER                           STM32_TIM2_NUMBER
#define ST_CLOCK_SRC                        STM32_TIMCLK1
#define ST_ENABLE_CLOCK()                   rccEnableTIM2(FALSE)

#elif STM32_ST_USE_TIMER == 3
#if (OSAL_ST_RESOLUTION == 32) && !STM32_TIM3_IS_32BITS
#error "TIM3 is not a 32bits timer"
#endif

#define ST_HANDLER                          STM32_TIM3_HANDLER
#define ST_NUMBER                           STM32_TIM3_NUMBER
#define ST_CLOCK_SRC                        STM32_TIMCLK1
#define ST_ENABLE_CLOCK()                   rccEnableTIM3(FALSE)

#elif STM32_ST_USE_TIMER == 4
#if (OSAL_ST_RESOLUTION == 32) && !STM32_TIM4_IS_32BITS
#error "TIM4 is not a 32bits timer"
#endif

#define ST_HANDLER                          STM32_TIM4_HANDLER
#define ST_NUMBER                           STM32_TIM4_NUMBER
#define ST_CLOCK_SRC                        STM32_TIMCLK1
#define ST_ENABLE_CLOCK()                   rccEnableTIM4(FALSE)

#elif STM32_ST_USE_TIMER == 5
#if (OSAL_ST_RESOLUTION == 32) && !STM32_TIM5_IS_32BITS
#error "TIM5 is not a 32bits timer"
#endif

#define ST_HANDLER                          STM32_TIM5_HANDLER
#define ST_NUMBER                           STM32_TIM5_NUMBER
#define ST_CLOCK_SRC                        STM32_TIMCLK1
#define ST_ENABLE_CLOCK()                   rccEnableTIM5(FALSE)

#else
#error "STM32_ST_USE_TIMER specifies an unsupported timer"
#endif

#if ST_CLOCK_SRC % OSAL_SYSTICK_FREQUENCY != 0
#error "the selected ST frequency is not obtainable because integer rounding"
#endif

#if (ST_CLOCK_SRC / OSAL_SYSTICK_FREQUENCY) - 1 > 0xFFFF
#error "the selected ST frequency is not obtainable because TIM timer prescaler limits"
#endif

#endif /* OSAL_ST_MODE == OSAL_ST_MODE_FREERUNNING */

#if OSAL_ST_MODE == OSAL_ST_MODE_PERIODIC

#if STM32_HCLK % OSAL_SYSTICK_FREQUENCY != 0
#error "the selected ST frequency is not obtainable because integer rounding"
#endif

#if (STM32_HCLK / OSAL_SYSTICK_FREQUENCY) - 1 > 0xFFFFFF
#error "the selected ST frequency is not obtainable because SysTick timer counter limits"
#endif

#endif /* OSAL_ST_MODE == OSAL_ST_MODE_PERIODIC */

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

/*===========================================================================*/
/* Driver local types.                                                       */
/*===========================================================================*/

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

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

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

#if (OSAL_ST_MODE == OSAL_ST_MODE_PERIODIC) || defined(__DOXYGEN__)
/**
 * @brief   System Timer vector.
 * @details This interrupt is used for system tick in periodic mode.
 *
 * @isr
 */
OSAL_IRQ_HANDLER(SysTick_Handler) {

  OSAL_IRQ_PROLOGUE();

  osalSysLockFromISR();
  osalOsTimerHandlerI();
  osalSysUnlockFromISR();

  OSAL_IRQ_EPILOGUE();
}
#endif /* OSAL_ST_MODE == OSAL_ST_MODE_PERIODIC */

#if (OSAL_ST_MODE == OSAL_ST_MODE_FREERUNNING) || defined(__DOXYGEN__)
/**
 * @brief   TIM2 interrupt handler.
 * @details This interrupt is used for system tick in free running mode.
 *
 * @isr
 */
OSAL_IRQ_HANDLER(ST_HANDLER) {

  OSAL_IRQ_PROLOGUE();

  STM32_ST_TIM->SR = 0;

  osalSysLockFromISR();
  osalOsTimerHandlerI();
  osalSysUnlockFromISR();

  OSAL_IRQ_EPILOGUE();
}
#endif /* OSAL_ST_MODE == OSAL_ST_MODE_FREERUNNING */

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

/**
 * @brief   Low level ST driver initialization.
 *
 * @notapi
 */
void st_lld_init(void) {

#if OSAL_ST_MODE == OSAL_ST_MODE_FREERUNNING
  /* Free running counter mode.*/

  /* Enabling timer clock.*/
  ST_ENABLE_CLOCK();

  /* Initializing the counter in free running mode.*/
  STM32_ST_TIM->PSC    = (ST_CLOCK_SRC / OSAL_SYSTICK_FREQUENCY) - 1;
  STM32_ST_TIM->ARR    = ST_ARR_INIT;
  STM32_ST_TIM->CCMR1  = 0;
  STM32_ST_TIM->CCR[0] = 0;
  STM32_ST_TIM->DIER   = 0;
  STM32_ST_TIM->CR2    = 0;
  STM32_ST_TIM->EGR    = TIM_EGR_UG;
  STM32_ST_TIM->CR1    = TIM_CR1_CEN;

  /* IRQ enabled.*/
  nvicEnableVector(ST_NUMBER, STM32_ST_IRQ_PRIORITY);
#endif /* OSAL_ST_MODE == OSAL_ST_MODE_FREERUNNING */

#if OSAL_ST_MODE == OSAL_ST_MODE_PERIODIC
  /* Periodic systick mode, the Cortex-Mx internal systick timer is used
     in this mode.*/
  SysTick->LOAD = (STM32_HCLK / OSAL_SYSTICK_FREQUENCY) - 1;
  SysTick->VAL = 0;
  SysTick->CTRL = SysTick_CTRL_CLKSOURCE_Msk |
                  SysTick_CTRL_ENABLE_Msk |
                  SysTick_CTRL_TICKINT_Msk;

  /* IRQ enabled.*/
  nvicSetSystemHandlerPriority(SysTick_IRQn, STM32_ST_IRQ_PRIORITY);
#endif /* OSAL_ST_MODE == OSAL_ST_MODE_PERIODIC */
}

#endif /* OSAL_ST_MODE != OSAL_ST_MODE_NONE */

/** @} */