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Diffstat (limited to 'drivers/staging/echo/fir.h')
| -rw-r--r-- | drivers/staging/echo/fir.h | 216 |
1 files changed, 0 insertions, 216 deletions
diff --git a/drivers/staging/echo/fir.h b/drivers/staging/echo/fir.h deleted file mode 100644 index 7b9fabf1fea..00000000000 --- a/drivers/staging/echo/fir.h +++ /dev/null @@ -1,216 +0,0 @@ -/* - * 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. - */ - -#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. -*/ - -/* - * 16 bit integer FIR descriptor. This defines the working state for a single - * instance of an FIR filter using 16 bit integer coefficients. - */ -struct fir16_state_t { - int taps; - int curr_pos; - const int16_t *coeffs; - int16_t *history; -}; - -/* - * 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. - */ -struct fir32_state_t { - int taps; - int curr_pos; - const int32_t *coeffs; - int16_t *history; -}; - -/* - * Floating point FIR descriptor. This defines the working state for a single - * instance of an FIR filter using floating point coefficients and data. - */ -struct fir_float_state_t { - int taps; - int curr_pos; - const float *coeffs; - float *history; -}; - -static inline const int16_t *fir16_create(struct fir16_state_t *fir, - const int16_t *coeffs, int taps) -{ - fir->taps = taps; - fir->curr_pos = taps - 1; - fir->coeffs = coeffs; -#if defined(__bfin__) - fir->history = kcalloc(2 * taps, sizeof(int16_t), GFP_KERNEL); -#else - fir->history = kcalloc(taps, sizeof(int16_t), GFP_KERNEL); -#endif - return fir->history; -} - -static inline void fir16_flush(struct fir16_state_t *fir) -{ -#if defined(__bfin__) - memset(fir->history, 0, 2 * fir->taps * sizeof(int16_t)); -#else - memset(fir->history, 0, fir->taps * sizeof(int16_t)); -#endif -} - -static inline void fir16_free(struct fir16_state_t *fir) -{ - kfree(fir->history); -} - -#ifdef __bfin__ -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 - -static inline int16_t fir16(struct fir16_state_t *fir, int16_t sample) -{ - int32_t y; -#if defined(__bfin__) - 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); -} - -static inline const int16_t *fir32_create(struct fir32_state_t *fir, - const int32_t *coeffs, int taps) -{ - fir->taps = taps; - fir->curr_pos = taps - 1; - fir->coeffs = coeffs; - fir->history = kcalloc(taps, sizeof(int16_t), GFP_KERNEL); - return fir->history; -} - -static inline void fir32_flush(struct fir32_state_t *fir) -{ - memset(fir->history, 0, fir->taps * sizeof(int16_t)); -} - -static inline void fir32_free(struct fir32_state_t *fir) -{ - kfree(fir->history); -} - -static inline int16_t fir32(struct 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); -} - -#endif |