/* SPDX-License-Identifier: BSD-3-Clause

*

* Copyright(c) 2022 Intel Corporation. All rights reserved.

*

* Author: Andrula Song <andrula.song@intel.com>

*/

#ifndef __SOF_MATH_IIR_DF1_H__

#define __SOF_MATH_IIR_DF1_H__

#include <stddef.h>

#include <stdint.h>

#include <sof/common.h>

#define IIR_DF1_NUM_STATE 4

#define SOF_IIR_DF1_4TH_NUM_BIQUADS 2

struct iir_state_df1 {

unsigned int biquads; /* Number of IIR 2nd order sections total */

unsigned int biquads_in_series; /* Number of IIR 2nd order sections

* in series.

*/

int32_t *coef; /* Pointer to IIR coefficients */

int32_t *delay; /* Pointer to IIR delay line */

};

struct sof_eq_iir_header;

int iir_init_coef_df1(struct iir_state_df1 *iir,

struct sof_eq_iir_header *config);

int iir_delay_size_df1(struct sof_eq_iir_header *config);

void iir_init_delay_df1(struct iir_state_df1 *iir, int32_t **state);

void iir_reset_df1(struct iir_state_df1 *iir);

/**

* Calculate IIR filter consisting of biquads

* @param iir IIR state with configured biquad coefficients and delay lines data

* @param x Single s32 Q1.31 format input sample

* @return Single s32 Q1.31 format output samples

*/

int32_t iir_df1(struct iir_state_df1 *iir, int32_t x);

/**

* Calculate IIR filter consisting of biquads, special simplified version for

* 4th order filter with two biquads in series. Note: There are no checks for

* iir struct members.

* @param iir IIR state with configured biquad coefficients and delay lines data

* @param x Single s32 Q1.31 format input sample

* @return Single s32 Q1.31 format output samples

*/

int32_t iir_df1_4th(struct iir_state_df1 *iir, int32_t x);

/* Inline functions */

#if SOF_USE_MIN_HIFI(3, FILTER)

#include "iir_df1_hifi3.h"

#else

#include "iir_df1_generic.h"

#endif

#endif