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Diffstat (limited to 'drivers/staging/echo/fir.h')
-rw-r--r-- | drivers/staging/echo/fir.h | 369 |
1 files changed, 369 insertions, 0 deletions
diff --git a/drivers/staging/echo/fir.h b/drivers/staging/echo/fir.h new file mode 100644 index 00000000000..e1bfc499488 --- /dev/null +++ b/drivers/staging/echo/fir.h @@ -0,0 +1,369 @@ +/* + * SpanDSP - a series of DSP components for telephony + * + * fir.h - General telephony FIR routines + * + * Written by Steve Underwood <steveu@coppice.org> + * + * Copyright (C) 2002 Steve Underwood + * + * All rights reserved. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2, as + * published by the Free Software Foundation. + * + * This program 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, write to the Free Software + * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. + * + * $Id: fir.h,v 1.8 2006/10/24 13:45:28 steveu Exp $ + */ + +/*! \page fir_page FIR filtering +\section fir_page_sec_1 What does it do? +???. + +\section fir_page_sec_2 How does it work? +???. +*/ + +#if !defined(_FIR_H_) +#define _FIR_H_ + +/* + Blackfin NOTES & IDEAS: + + A simple dot product function is used to implement the filter. This performs + just one MAC/cycle which is inefficient but was easy to implement as a first + pass. The current Blackfin code also uses an unrolled form of the filter + history to avoid 0 length hardware loop issues. This is wasteful of + memory. + + Ideas for improvement: + + 1/ Rewrite filter for dual MAC inner loop. The issue here is handling + history sample offsets that are 16 bit aligned - the dual MAC needs + 32 bit aligmnent. There are some good examples in libbfdsp. + + 2/ Use the hardware circular buffer facility tohalve memory usage. + + 3/ Consider using internal memory. + + Using less memory might also improve speed as cache misses will be + reduced. A drop in MIPs and memory approaching 50% should be + possible. + + The foreground and background filters currenlty use a total of + about 10 MIPs/ch as measured with speedtest.c on a 256 TAP echo + can. +*/ + +#if defined(USE_MMX) || defined(USE_SSE2) +#include "mmx.h" +#endif + +/*! + 16 bit integer FIR descriptor. This defines the working state for a single + instance of an FIR filter using 16 bit integer coefficients. +*/ +typedef struct +{ + int taps; + int curr_pos; + const int16_t *coeffs; + int16_t *history; +} fir16_state_t; + +/*! + 32 bit integer FIR descriptor. This defines the working state for a single + instance of an FIR filter using 32 bit integer coefficients, and filtering + 16 bit integer data. +*/ +typedef struct +{ + int taps; + int curr_pos; + const int32_t *coeffs; + int16_t *history; +} fir32_state_t; + +/*! + Floating point FIR descriptor. This defines the working state for a single + instance of an FIR filter using floating point coefficients and data. +*/ +typedef struct +{ + int taps; + int curr_pos; + const float *coeffs; + float *history; +} fir_float_state_t; + +#ifdef __cplusplus +extern "C" { +#endif + +static __inline__ const int16_t *fir16_create(fir16_state_t *fir, + const int16_t *coeffs, + int taps) +{ + fir->taps = taps; + fir->curr_pos = taps - 1; + fir->coeffs = coeffs; +#if defined(USE_MMX) || defined(USE_SSE2) || defined(__BLACKFIN_ASM__) + if ((fir->history = malloc(2*taps*sizeof(int16_t)))) + memset(fir->history, 0, 2*taps*sizeof(int16_t)); +#else + if ((fir->history = (int16_t *) malloc(taps*sizeof(int16_t)))) + memset(fir->history, 0, taps*sizeof(int16_t)); +#endif + return fir->history; +} +/*- End of function --------------------------------------------------------*/ + +static __inline__ void fir16_flush(fir16_state_t *fir) +{ +#if defined(USE_MMX) || defined(USE_SSE2) || defined(__BLACKFIN_ASM__) + memset(fir->history, 0, 2*fir->taps*sizeof(int16_t)); +#else + memset(fir->history, 0, fir->taps*sizeof(int16_t)); +#endif +} +/*- End of function --------------------------------------------------------*/ + +static __inline__ void fir16_free(fir16_state_t *fir) +{ + free(fir->history); +} +/*- End of function --------------------------------------------------------*/ + +#ifdef __BLACKFIN_ASM__ +static inline int32_t dot_asm(short *x, short *y, int len) +{ + int dot; + + len--; + + __asm__ + ( + "I0 = %1;\n\t" + "I1 = %2;\n\t" + "A0 = 0;\n\t" + "R0.L = W[I0++] || R1.L = W[I1++];\n\t" + "LOOP dot%= LC0 = %3;\n\t" + "LOOP_BEGIN dot%=;\n\t" + "A0 += R0.L * R1.L (IS) || R0.L = W[I0++] || R1.L = W[I1++];\n\t" + "LOOP_END dot%=;\n\t" + "A0 += R0.L*R1.L (IS);\n\t" + "R0 = A0;\n\t" + "%0 = R0;\n\t" + : "=&d" (dot) + : "a" (x), "a" (y), "a" (len) + : "I0", "I1", "A1", "A0", "R0", "R1" + ); + + return dot; +} +#endif +/*- End of function --------------------------------------------------------*/ + +static __inline__ int16_t fir16(fir16_state_t *fir, int16_t sample) +{ + int32_t y; +#if defined(USE_MMX) + int i; + mmx_t *mmx_coeffs; + mmx_t *mmx_hist; + + fir->history[fir->curr_pos] = sample; + fir->history[fir->curr_pos + fir->taps] = sample; + + mmx_coeffs = (mmx_t *) fir->coeffs; + mmx_hist = (mmx_t *) &fir->history[fir->curr_pos]; + i = fir->taps; + pxor_r2r(mm4, mm4); + /* 8 samples per iteration, so the filter must be a multiple of 8 long. */ + while (i > 0) + { + movq_m2r(mmx_coeffs[0], mm0); + movq_m2r(mmx_coeffs[1], mm2); + movq_m2r(mmx_hist[0], mm1); + movq_m2r(mmx_hist[1], mm3); + mmx_coeffs += 2; + mmx_hist += 2; + pmaddwd_r2r(mm1, mm0); + pmaddwd_r2r(mm3, mm2); + paddd_r2r(mm0, mm4); + paddd_r2r(mm2, mm4); + i -= 8; + } + movq_r2r(mm4, mm0); + psrlq_i2r(32, mm0); + paddd_r2r(mm0, mm4); + movd_r2m(mm4, y); + emms(); +#elif defined(USE_SSE2) + int i; + xmm_t *xmm_coeffs; + xmm_t *xmm_hist; + + fir->history[fir->curr_pos] = sample; + fir->history[fir->curr_pos + fir->taps] = sample; + + xmm_coeffs = (xmm_t *) fir->coeffs; + xmm_hist = (xmm_t *) &fir->history[fir->curr_pos]; + i = fir->taps; + pxor_r2r(xmm4, xmm4); + /* 16 samples per iteration, so the filter must be a multiple of 16 long. */ + while (i > 0) + { + movdqu_m2r(xmm_coeffs[0], xmm0); + movdqu_m2r(xmm_coeffs[1], xmm2); + movdqu_m2r(xmm_hist[0], xmm1); + movdqu_m2r(xmm_hist[1], xmm3); + xmm_coeffs += 2; + xmm_hist += 2; + pmaddwd_r2r(xmm1, xmm0); + pmaddwd_r2r(xmm3, xmm2); + paddd_r2r(xmm0, xmm4); + paddd_r2r(xmm2, xmm4); + i -= 16; + } + movdqa_r2r(xmm4, xmm0); + psrldq_i2r(8, xmm0); + paddd_r2r(xmm0, xmm4); + movdqa_r2r(xmm4, xmm0); + psrldq_i2r(4, xmm0); + paddd_r2r(xmm0, xmm4); + movd_r2m(xmm4, y); +#elif defined(__BLACKFIN_ASM__) + fir->history[fir->curr_pos] = sample; + fir->history[fir->curr_pos + fir->taps] = sample; + y = dot_asm((int16_t*)fir->coeffs, &fir->history[fir->curr_pos], fir->taps); +#else + int i; + int offset1; + int offset2; + + fir->history[fir->curr_pos] = sample; + + offset2 = fir->curr_pos; + offset1 = fir->taps - offset2; + y = 0; + for (i = fir->taps - 1; i >= offset1; i--) + y += fir->coeffs[i]*fir->history[i - offset1]; + for ( ; i >= 0; i--) + y += fir->coeffs[i]*fir->history[i + offset2]; +#endif + if (fir->curr_pos <= 0) + fir->curr_pos = fir->taps; + fir->curr_pos--; + return (int16_t) (y >> 15); +} +/*- End of function --------------------------------------------------------*/ + +static __inline__ const int16_t *fir32_create(fir32_state_t *fir, + const int32_t *coeffs, + int taps) +{ + fir->taps = taps; + fir->curr_pos = taps - 1; + fir->coeffs = coeffs; + fir->history = (int16_t *) malloc(taps*sizeof(int16_t)); + if (fir->history) + memset(fir->history, '\0', taps*sizeof(int16_t)); + return fir->history; +} +/*- End of function --------------------------------------------------------*/ + +static __inline__ void fir32_flush(fir32_state_t *fir) +{ + memset(fir->history, 0, fir->taps*sizeof(int16_t)); +} +/*- End of function --------------------------------------------------------*/ + +static __inline__ void fir32_free(fir32_state_t *fir) +{ + free(fir->history); +} +/*- End of function --------------------------------------------------------*/ + +static __inline__ int16_t fir32(fir32_state_t *fir, int16_t sample) +{ + int i; + int32_t y; + int offset1; + int offset2; + + fir->history[fir->curr_pos] = sample; + offset2 = fir->curr_pos; + offset1 = fir->taps - offset2; + y = 0; + for (i = fir->taps - 1; i >= offset1; i--) + y += fir->coeffs[i]*fir->history[i - offset1]; + for ( ; i >= 0; i--) + y += fir->coeffs[i]*fir->history[i + offset2]; + if (fir->curr_pos <= 0) + fir->curr_pos = fir->taps; + fir->curr_pos--; + return (int16_t) (y >> 15); +} +/*- End of function --------------------------------------------------------*/ + +#ifndef __KERNEL__ +static __inline__ const float *fir_float_create(fir_float_state_t *fir, + const float *coeffs, + int taps) +{ + fir->taps = taps; + fir->curr_pos = taps - 1; + fir->coeffs = coeffs; + fir->history = (float *) malloc(taps*sizeof(float)); + if (fir->history) + memset(fir->history, '\0', taps*sizeof(float)); + return fir->history; +} +/*- End of function --------------------------------------------------------*/ + +static __inline__ void fir_float_free(fir_float_state_t *fir) +{ + free(fir->history); +} +/*- End of function --------------------------------------------------------*/ + +static __inline__ int16_t fir_float(fir_float_state_t *fir, int16_t sample) +{ + int i; + float y; + int offset1; + int offset2; + + fir->history[fir->curr_pos] = sample; + + offset2 = fir->curr_pos; + offset1 = fir->taps - offset2; + y = 0; + for (i = fir->taps - 1; i >= offset1; i--) + y += fir->coeffs[i]*fir->history[i - offset1]; + for ( ; i >= 0; i--) + y += fir->coeffs[i]*fir->history[i + offset2]; + if (fir->curr_pos <= 0) + fir->curr_pos = fir->taps; + fir->curr_pos--; + return (int16_t) y; +} +/*- End of function --------------------------------------------------------*/ +#endif + +#ifdef __cplusplus +} +#endif + +#endif +/*- End of file ------------------------------------------------------------*/ |