/* ----------------------------------------------------------------------
* Copyright (C) 2010-2014 ARM Limited. All rights reserved.
*
* $Date: 16/10/14 6:01p $Revision:  V.1.4.5
*
* Project:      CMSIS DSP Library
* Title:        arm_pid_init_q15.c
*
* Description:  Q15 PID Control initialization function
*
* Target Processor: Cortex-M4/Cortex-M3/Cortex-M0
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*   - Redistributions of source code must retain the above copyright
*     notice, this list of conditions and the following disclaimer.
*   - Redistributions in binary form must reproduce the above copyright
*     notice, this list of conditions and the following disclaimer in
*     the documentation and/or other materials provided with the
*     distribution.
*   - Neither the name of ARM LIMITED nor the names of its contributors
*     may be used to endorse or promote products derived from this
*     software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
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* POSSIBILITY OF SUCH DAMAGE.
* -------------------------------------------------------------------- */

#include "arm_math.h"

/**
* @addtogroup PID
* @{
*/

/**
 * @details
 * @param[in,out] *S points to an instance of the Q15 PID structure.
 * @param[in]     resetStateFlag  flag to reset the state. 0 = no change in state 1 = reset the state.
 * @return none.
 * \par Description:
 * \par
 * The <code>resetStateFlag</code> specifies whether to set state to zero or not. \n
 * The function computes the structure fields: <code>A0</code>, <code>A1</code> <code>A2</code>
 * using the proportional gain( \c Kp), integral gain( \c Ki) and derivative gain( \c Kd)
 * also sets the state variables to all zeros.
 */

void arm_pid_init_q15(
    arm_pid_instance_q15 * S,
    int32_t resetStateFlag)
{

#ifndef ARM_MATH_CM0_FAMILY

    /* Run the below code for Cortex-M4 and Cortex-M3 */

    /* Derived coefficient A0 */
    S->A0 = __QADD16(__QADD16(S->Kp, S->Ki), S->Kd);

    /* Derived coefficients and pack into A1 */

#ifndef  ARM_MATH_BIG_ENDIAN

    S->A1 = __PKHBT(-__QADD16(__QADD16(S->Kd, S->Kd), S->Kp), S->Kd, 16);

#else

    S->A1 = __PKHBT(S->Kd, -__QADD16(__QADD16(S->Kd, S->Kd), S->Kp), 16);

#endif /*      #ifndef  ARM_MATH_BIG_ENDIAN    */

    /* Check whether state needs reset or not */
    if(resetStateFlag)
    {
        /* Clear the state buffer.  The size will be always 3 samples */
        memset(S->state, 0, 3u * sizeof(q15_t));
    }

#else

    /* Run the below code for Cortex-M0 */

    q31_t temp;                                    /*to store the sum */

    /* Derived coefficient A0 */
    temp = S->Kp + S->Ki + S->Kd;
    S->A0 = (q15_t) __SSAT(temp, 16);

    /* Derived coefficients and pack into A1 */
    temp = -(S->Kd + S->Kd + S->Kp);
    S->A1 = (q15_t) __SSAT(temp, 16);
    S->A2 = S->Kd;



    /* Check whether state needs reset or not */
    if(resetStateFlag)
    {
        /* Clear the state buffer.  The size will be always 3 samples */
        memset(S->state, 0, 3u * sizeof(q15_t));
    }

#endif /* #ifndef ARM_MATH_CM0_FAMILY */

}

/**
 * @} end of PID group
 */
