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Commit 27713c8b authored by Reinhard Nissl's avatar Reinhard Nissl Committed by Mauro Carvalho Chehab
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V4L/DVB (9449): Code Simplification: use do_div() instead 



Signed-off-by: default avatarReinhard Nissl <rnissl@gmx.de>
Signed-off-by: default avatarManu Abraham <manu@linuxtv.org>
Signed-off-by: default avatarMauro Carvalho Chehab <mchehab@redhat.com>
parent 56137411

drivers/media/dvb/frontends/stb0899_algo.c

+34 −35
Original line number Diff line number Diff line
@@ -23,27 +23,12 @@ 
#include "stb0899_priv.h"

#include "stb0899_reg.h"



/*

 * BinaryFloatDiv

 * float division with integer

 */

static long BinaryFloatDiv(long n1, long n2, int precision)

inline u32 stb0899_do_div(u64 n, u32 d)

{

	int i = 0;

	long result = 0;

	/* wrap do_div() for ease of use */



	while (i <= precision) {

		if (n1 < n2) {

			result *= 2;

			n1 *= 2;

		} else {

			result = result * 2 + 1;

			n1 = (n1 - n2) * 2;

		}

		i++;

	}



	return result;

	do_div(n, d);

	return n;

}



/*
@@ -52,15 +37,15 @@ static long BinaryFloatDiv(long n1, long n2, int precision) 
 */

static u32 stb0899_calc_srate(u32 master_clk, u8 *sfr)

{

	u32 tmp, tmp2, mclk;

	u64 tmp;



	mclk  =  master_clk / 4096L; /* MasterClock * 10 / 2^20	*/

	tmp  = (((u32) sfr[0] << 12) + ((u32) sfr[1] << 4)) / 16;

	/* srate = (SFR * master_clk) >> 20 */



	tmp *= mclk;

	tmp /= 16;

	tmp2 = ((u32) sfr[2] * mclk) / 256;

	tmp += tmp2;

	/* sfr is of size 20 bit, stored with an offset of 4 bit */

	tmp = (((u32)sfr[0]) << 16) | (((u32)sfr[1]) << 8) | sfr[2];

	tmp &= ~0xf;

	tmp *= master_clk;

	tmp >>= 24;



	return tmp;

}
@@ -72,7 +57,7 @@ static u32 stb0899_calc_srate(u32 master_clk, u8 *sfr) 
u32 stb0899_get_srate(struct stb0899_state *state)

{

	struct stb0899_internal *internal = &state->internal;

	u8 sfr[4];

	u8 sfr[3];



	stb0899_read_regs(state, STB0899_SFRH, sfr, 3);
@@ -101,16 +86,30 @@ static u32 stb0899_set_srate(struct stb0899_state *state, u32 master_clk, u32 sr 
	 */

//	srate_up += (srate_up * 3) / 100;



	tmp = BinaryFloatDiv(srate, master_clk, 20);

//	tmp_up = BinaryFloatDiv(srate_up, master_clk, 20);

	/*

	 * srate = (SFR * master_clk) >> 20

	 *      <=>

	 *   SFR = srate << 20 / master_clk

	 *

	 * rounded:

	 *   SFR = (srate << 21 + master_clk) / (2 * master_clk)

	 *

	 * stored as 20 bit number with an offset of 4 bit:

	 *   sfr = SFR << 4;

	 */

//	tmp_up = stb0899_do_div((((u64)srate_up) << 21) + master_clk, 2 * master_clk);

//	tmp_up <<= 4;



	tmp = stb0899_do_div((((u64)srate) << 21) + master_clk, 2 * master_clk);

	tmp <<= 4;



//	sfr_up[0] = (tmp_up >> 12) & 0xff;

//	sfr_up[1] = (tmp_up >>  4) & 0xff;

//	sfr_up[2] =  tmp_up & 0x0f;

//	sfr_up[0] = tmp_up >> 16;

//	sfr_up[1] = tmp_up >>  8;

//	sfr_up[2] = tmp_up;



	sfr[0] = (tmp >> 12) & 0xff;

	sfr[1] = (tmp >>  4) & 0xff;

	sfr[2] = (tmp <<  4) & 0xf0;

	sfr[0] = tmp >> 16;

	sfr[1] = tmp >>  8;

	sfr[2] = tmp;



//	stb0899_write_regs(state, STB0899_SFRUPH, sfr_up, 3);

	stb0899_write_regs(state, STB0899_SFRH, sfr, 3);