Release 4.7 drivers/misc/echo/fir.h
/*
* 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;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| david rowe | david rowe | 82 | 90.11% | 1 | 20.00% |
| pekka j enberg | pekka j enberg | 6 | 6.59% | 1 | 20.00% |
| j.r. mauro | j.r. mauro | 1 | 1.10% | 1 | 20.00% |
| alexander beregalov | alexander beregalov | 1 | 1.10% | 1 | 20.00% |
| tzafrir cohen | tzafrir cohen | 1 | 1.10% | 1 | 20.00% |
| Total | 91 | 100.00% | 5 | 100.00% |
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
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| david rowe | david rowe | 57 | 95.00% | 1 | 25.00% |
| alexander beregalov | alexander beregalov | 1 | 1.67% | 1 | 25.00% |
| j.r. mauro | j.r. mauro | 1 | 1.67% | 1 | 25.00% |
| tzafrir cohen | tzafrir cohen | 1 | 1.67% | 1 | 25.00% |
| Total | 60 | 100.00% | 4 | 100.00% |
static inline void fir16_free(struct fir16_state_t *fir)
{
kfree(fir->history);
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| david rowe | david rowe | 16 | 84.21% | 1 | 25.00% |
| alexander beregalov | alexander beregalov | 1 | 5.26% | 1 | 25.00% |
| j.r. mauro | j.r. mauro | 1 | 5.26% | 1 | 25.00% |
| pekka j enberg | pekka j enberg | 1 | 5.26% | 1 | 25.00% |
| Total | 19 | 100.00% | 4 | 100.00% |
#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;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| david rowe | david rowe | 27 | 96.43% | 1 | 50.00% |
| alexander beregalov | alexander beregalov | 1 | 3.57% | 1 | 50.00% |
| Total | 28 | 100.00% | 2 | 100.00% |
#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);
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| david rowe | david rowe | 210 | 98.59% | 1 | 25.00% |
| j.r. mauro | j.r. mauro | 1 | 0.47% | 1 | 25.00% |
| alexander beregalov | alexander beregalov | 1 | 0.47% | 1 | 25.00% |
| tzafrir cohen | tzafrir cohen | 1 | 0.47% | 1 | 25.00% |
| Total | 213 | 100.00% | 4 | 100.00% |
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;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| david rowe | david rowe | 58 | 92.06% | 1 | 25.00% |
| pekka j enberg | pekka j enberg | 3 | 4.76% | 1 | 25.00% |
| j.r. mauro | j.r. mauro | 1 | 1.59% | 1 | 25.00% |
| alexander beregalov | alexander beregalov | 1 | 1.59% | 1 | 25.00% |
| Total | 63 | 100.00% | 4 | 100.00% |
static inline void fir32_flush(struct fir32_state_t *fir)
{
memset(fir->history, 0, fir->taps * sizeof(int16_t));
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| david rowe | david rowe | 28 | 93.33% | 1 | 33.33% |
| j.r. mauro | j.r. mauro | 1 | 3.33% | 1 | 33.33% |
| alexander beregalov | alexander beregalov | 1 | 3.33% | 1 | 33.33% |
| Total | 30 | 100.00% | 3 | 100.00% |
static inline void fir32_free(struct fir32_state_t *fir)
{
kfree(fir->history);
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| david rowe | david rowe | 16 | 84.21% | 1 | 25.00% |
| j.r. mauro | j.r. mauro | 1 | 5.26% | 1 | 25.00% |
| alexander beregalov | alexander beregalov | 1 | 5.26% | 1 | 25.00% |
| pekka j enberg | pekka j enberg | 1 | 5.26% | 1 | 25.00% |
| Total | 19 | 100.00% | 4 | 100.00% |
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);
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| david rowe | david rowe | 148 | 98.67% | 1 | 33.33% |
| alexander beregalov | alexander beregalov | 1 | 0.67% | 1 | 33.33% |
| j.r. mauro | j.r. mauro | 1 | 0.67% | 1 | 33.33% |
| Total | 150 | 100.00% | 3 | 100.00% |
#endif
Overall Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| david rowe | david rowe | 713 | 94.44% | 1 | 16.67% |
| j.r. mauro | j.r. mauro | 14 | 1.85% | 1 | 16.67% |
| pekka j enberg | pekka j enberg | 11 | 1.46% | 1 | 16.67% |
| alexander beregalov | alexander beregalov | 10 | 1.32% | 1 | 16.67% |
| tzafrir cohen | tzafrir cohen | 4 | 0.53% | 1 | 16.67% |
| greg kroah-hartman | greg kroah-hartman | 3 | 0.40% | 1 | 16.67% |
| Total | 755 | 100.00% | 6 | 100.00% |
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