[PATCH] atbm8830: replace 64-bit division and floating point usage

[David T. L. Wong]

Randy Dunlap wrote:
> On Mon, 30 Nov 2009 10:07:21 -0800 Randy Dunlap wrote:
>
> > Stephen Rothwell wrote:
> > > Hi all,
> > >
> > > Changes since 20091127:
> > >
> > > The v4l-dvb tree lost its conflict.
> >
> > on i386 (X86_32):
> >
> > a 'double' variable is used, causing:
> >
> > ERROR: "__floatunsidf" [drivers/media/common/tuners/max2165.ko] undefined!
> > ERROR: "__adddf3" [drivers/media/common/tuners/max2165.ko] undefined!
> > ERROR: "__fixunsdfsi" [drivers/media/common/tuners/max2165.ko] undefined!
>
>
> linux-next-20091202:
>
> still have this one (above) and similar with
> drivers/media/dvb/frontends/atbm8830.c:
>
> drivers/built-in.o: In function `atbm8830_init':
> atbm8830.c:(.text+0x9012f9): undefined reference to `__udivdi3'
> atbm8830.c:(.text+0x901384): undefined reference to `__floatunsidf'
> atbm8830.c:(.text+0x901395): undefined reference to `__muldf3'
> atbm8830.c:(.text+0x9013a5): undefined reference to `__floatunsidf'
> atbm8830.c:(.text+0x9013b2): undefined reference to `__divdf3'
> atbm8830.c:(.text+0x9013c3): undefined reference to `__muldf3'
> atbm8830.c:(.text+0x9013cd): undefined reference to `__fixunsdfsi'
>
> ---
> ~Randy
> --
> To unsubscribe from this list: send the line "unsubscribe linux-media" in
> the body of a message to majordomo@xxxxxxxxxxxxxxx
> More majordomo info at  http://vger.kernel.org/majordomo-info.html

This patch replace 64-bit division by do_div() macro and remove usage of 
floating point variable

Signed-off-by: David T. L. Wong <davidtlwong@xxxxxxxxx>
diff --git a/linux/drivers/media/dvb/frontends/atbm8830.c b/linux/drivers/media/dvb/frontends/atbm8830.c
--- a/linux/drivers/media/dvb/frontends/atbm8830.c
+++ b/linux/drivers/media/dvb/frontends/atbm8830.c
@@ -19,6 +19,7 @@
  *    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  */
 
+#include <asm/div64.h>
 #include "dvb_frontend.h"
 
 #include "atbm8830.h"
@@ -102,8 +103,12 @@
 static int set_osc_freq(struct atbm_state *priv, u32 freq /*in kHz*/)
 {
 	u32 val;
+	u64 t;
 
-	val = (u64)0x100000 * freq / 30400;
+	/* 0x100000 * freq / 30.4MHz */
+	t = (u64)0x100000 * freq;
+	do_div(t, 30400);
+	val = t;
 
 	atbm8830_write_reg(priv, REG_OSC_CLK, val);
 	atbm8830_write_reg(priv, REG_OSC_CLK + 1, val >> 8);
@@ -116,14 +121,18 @@
 {
 	
 	u32 fs = priv->config->osc_clk_freq;
-	double t;
+	u64 t;
 	u32 val;
 	u8 dat;
 
-	t = 2 * 3.141593 * (freq - fs) / fs * (1 << 22);
-	val = t;
+	if (freq != 0) {
+		/* 2 * PI * (freq - fs) / fs * (2 ^ 22) */
+		t = (u64) 2 * 31416 * (freq - fs);
+		t <<= 22;
+		do_div(t, fs);
+		do_div(t, 1000);
+		val = t;
 
-	if (freq != 0) {
 		atbm8830_write_reg(priv, REG_TUNER_BASEBAND, 1);
 		atbm8830_write_reg(priv, REG_IF_FREQ, val);
 		atbm8830_write_reg(priv, REG_IF_FREQ+1, val >> 8);