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V4L/DVB (11441): cx88-dsp: fixing 64bit math

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cx88-dsp: fixing 64bit math on 32bit kernels

Some gcc versions report the missing of __divdi3

[mchehab.redhat.com: CodingStyle fixes]

Signed-off-by: Miroslav Sustek <sustmidown@centrum.cz>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
This commit is contained in:
Miroslav Sustek
2009-04-06 20:07:04 -03:00
committed by Mauro Carvalho Chehab
parent 2325a6b986
commit 7561300a7c
1 changed files with 15 additions and 2 deletions
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17
drivers/media/video/cx88/cx88-dsp.c
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@@ -22,6 +22,7 @@
#include <linux/kernel.h> #include <linux/kernel.h>
#include <linux/module.h> #include <linux/module.h>
#include <linux/jiffies.h> #include <linux/jiffies.h>
#include <asm/div64.h>
#include "cx88.h" #include "cx88.h"
#include "cx88-reg.h" #include "cx88-reg.h"
@@ -100,13 +101,25 @@ static u32 int_goertzel(s16 x[], u32 N, u32 freq)
s32 s_prev2 = 0; s32 s_prev2 = 0;
s32 coeff = 2*int_cos(freq); s32 coeff = 2*int_cos(freq);
u32 i; u32 i;
u64 tmp;
u32 divisor;
for (i = 0; i < N; i++) { for (i = 0; i < N; i++) {
s32 s = x[i] + ((s64)coeff*s_prev/32768) - s_prev2; s32 s = x[i] + ((s64)coeff*s_prev/32768) - s_prev2;
s_prev2 = s_prev; s_prev2 = s_prev;
s_prev = s; s_prev = s;
} }
return (u32)(((s64)s_prev2*s_prev2 + (s64)s_prev*s_prev -
(s64)coeff*s_prev2*s_prev/32768)/N/N); tmp = (s64)s_prev2 * s_prev2 + (s64)s_prev * s_prev -
(s64)coeff * s_prev2 * s_prev / 32768;
/* XXX: N must be low enough so that N*N fits in s32.
* Else we need two divisions. */
divisor = N * N;
do_div(tmp, divisor);
return (u32) tmp;
} }
static u32 freq_magnitude(s16 x[], u32 N, u32 freq) static u32 freq_magnitude(s16 x[], u32 N, u32 freq)