/*
    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    LPC8xx/gpt_lld.h
 * @brief   LPC8xx GPT subsystem low level driver header.
 *
 * @addtogroup GPT
 * @{
 */

#ifndef _GPT_LLD_H_
#define _GPT_LLD_H_

#if HAL_USE_GPT || defined(__DOXYGEN__)

/*===========================================================================*/
/* Driver constants.                                                         */
/*===========================================================================*/

/*===========================================================================*/
/* Driver pre-compile time settings.                                         */
/*===========================================================================*/

/**
 * @brief   GPT1 driver enable switch.
 * @details If set to @p TRUE the support for GPT1 is included.
 * @note    The default is @p TRUE.
 */
#if !defined(LPC8xx_GPT_USE_MRT0) || defined(__DOXYGEN__)
#define LPC8xx_GPT_USE_MRT0              TRUE
#endif

/**
 * @brief   GPT2 driver enable switch.
 * @details If set to @p TRUE the support for GPT2 is included.
 * @note    The default is @p FALSE.
 */
#if !defined(LPC8xx_GPT_USE_MRT1) || defined(__DOXYGEN__)
#define LPC8xx_GPT_USE_MRT1              FALSE
#endif

/**
 * @brief   GPT3 driver enable switch.
 * @details If set to @p TRUE the support for GPT3 is included.
 * @note    The default is @p FALSE.
 */
#if !defined(LPC8xx_GPT_USE_MRT2) || defined(__DOXYGEN__)
#define LPC8xx_GPT_USE_MRT2              FALSE
#endif

/**
 * @brief   GPT4 driver enable switch.
 * @details If set to @p TRUE the support for GPT4 is included.
 * @note    The default is @p FALSE.
 */
#if !defined(LPC8xx_GPT_USE_MRT3) || defined(__DOXYGEN__)
#define LPC8xx_GPT_USE_MRT3              FALSE
#endif

/**
 * @brief   GPT interrupt priority level setting.
 */
#if !defined(LPC8xx_GPT_MRT_IRQ_PRIORITY) || defined(__DOXYGEN__)
#define LPC8xx_GPT_MRT_IRQ_PRIORITY     2
#endif


/*===========================================================================*/
/* Derived constants and error checks.                                       */
/*===========================================================================*/

#if !LPC8xx_GPT_USE_MRT0 && !LPC8xx_GPT_USE_MRT1 &&                   \
    !LPC8xx_GPT_USE_MRT2 && !LPC8xx_GPT_USE_MRT3
#error "GPT driver activated but no CT peripheral assigned"
#endif

/*===========================================================================*/
/* Driver data structures and types.                                         */
/*===========================================================================*/

/**
 * @brief   GPT frequency type.
 */
typedef uint32_t gptfreq_t;

/**
 * @brief   GPT counter type.
 */
typedef uint32_t gptcnt_t;

/**
 * @brief   Driver configuration structure.
 * @note    It could be empty on some architectures.
 */
typedef struct {
  /**
   * @brief   Timer clock in Hz.
   * @note    The low level can use assertions in order to catch invalid
   *          frequency specifications.
   */
  gptfreq_t                 frequency;
  /**
   * @brief   Timer callback pointer.
   * @note    This callback is invoked on GPT counter events.
   */
  gptcallback_t             callback;
  /* End of the mandatory fields.*/
} GPTConfig;

/**
 * @brief   Structure representing a GPT driver.
 */
struct GPTDriver {
  /**
   * @brief Driver state.
   */
  gptstate_t                state;
  /**
   * @brief Current configuration data.
   */
  const GPTConfig           *config;
  /* End of the mandatory fields.*/
  /**
   * @brief Pointer to the MRT Channelx registers block.
   */
  MRT_Channel_cfg_Type           *tmr;
  /**
   * @brief Prescaler.
   */
  uint32_t                  pr;
  /**
   * @brief channel bitmask.
   */
  uint32_t                  mask;
};

/*===========================================================================*/
/* Driver macros.                                                            */
/*===========================================================================*/

/**
 * @brief   Changes the interval of GPT peripheral.
 * @details This function changes the interval of a running GPT unit.
 * @pre     The GPT unit must have been activated using @p gptStart().
 * @pre     The GPT unit must have been running in continuous mode using
 *          @p gptStartContinuous().
 * @post    The GPT unit interval is changed to the new value.
 * @note    The function has effect at the next cycle start.
 *
 * @param[in] gptp      pointer to a @p GPTDriver object
 * @param[in] interval  new cycle time in timer ticks
 * @notapi
 */
#define gpt_lld_change_interval(gptp, interval)                               \
  ((gptp)->tmr->INTVAL = ((interval*(gptp)->pr) - 1))

/*===========================================================================*/
/* External declarations.                                                    */
/*===========================================================================*/

#if LPC8xx_GPT_USE_MRT0 && !defined(__DOXYGEN__)
extern GPTDriver GPTD1;
#endif

#if LPC8xx_GPT_USE_MRT1 && !defined(__DOXYGEN__)
extern GPTDriver GPTD2;
#endif

#if LPC8xx_GPT_USE_MRT2 && !defined(__DOXYGEN__)
extern GPTDriver GPTD3;
#endif

#if LPC8xx_GPT_USE_MRT3 && !defined(__DOXYGEN__)
extern GPTDriver GPTD4;
#endif

#ifdef __cplusplus
extern "C" {
#endif
  void gpt_lld_init(void);
  void gpt_lld_start(GPTDriver *gptp);
  void gpt_lld_stop(GPTDriver *gptp);
  void gpt_lld_start_timer(GPTDriver *gptp, gptcnt_t period);
  void gpt_lld_stop_timer(GPTDriver *gptp);
  void gpt_lld_polled_delay(GPTDriver *gptp, gptcnt_t interval);
#ifdef __cplusplus
}
#endif

#endif /* HAL_USE_GPT */

#endif /* _GPT_LLD_H_ */

/** @} */
