Aug 21 2008

V4L/DVB (8729): Use DIV_ROUND_UP 

Author: Julia Lawall <julia@diku.dk>

The kernel.h macro DIV_ROUND_UP performs the computation (((n) + (d) - 1) /
(d)) but is perhaps more readable.

An extract of the semantic patch that makes this change is as follows:
(http://www.emn.fr/x-info/coccinelle/)

// 
@haskernel@
@@

@depends on haskernel@
expression n,d;
@@

(
- (n + d - 1) / d
+ DIV_ROUND_UP(n,d)
|
- (n + (d - 1)) / d
+ DIV_ROUND_UP(n,d)
)

@depends on haskernel@
expression n,d;
@@

- DIV_ROUND_UP((n),d)
+ DIV_ROUND_UP(n,d)

@depends on haskernel@
expression n,d;
@@

- DIV_ROUND_UP(n,(d))
+ DIV_ROUND_UP(n,d)
// 

Signed-off-by: Julia Lawall 
Signed-off-by: Andrew Morton 
Signed-off-by: Mauro Carvalho Chehab 

---
 drivers/media/video/bw-qcam.c       | 4 ++--
 drivers/media/video/uvc/uvc_video.c | 2 +-
 drivers/media/video/zoran_device.c  | 4 ++--
 3 files changed, 5 insertions(+), 5 deletions(-)
 
diff --git a/drivers/media/video/bw-qcam.c b/drivers/media/video/bw-qcam.c
index 6e39e25..01f0770 100644
--- a/drivers/media/video/bw-qcam.c
+++ b/drivers/media/video/bw-qcam.c
@@ -495,7 +495,7 @@ static void qc_set(struct qcam_device *q)
 		val2 = (((q->port_mode & QC_MODE_MASK) == QC_BIDIR) ? 24 : 8) *
 		    q->transfer_scale;
 	}
-	val = (val + val2 - 1) / val2;
+	val = DIV_ROUND_UP(val, val2);
 	qc_command(q, 0x13);
 	qc_command(q, val);
 
@@ -651,7 +651,7 @@ static long qc_capture(struct qcam_device * q, char __user *buf, unsigned long l
 	transperline = q->width * q->bpp;
 	divisor = (((q->port_mode & QC_MODE_MASK) == QC_BIDIR) ? 24 : 8) *
 	    q->transfer_scale;
-	transperline = (transperline + divisor - 1) / divisor;
+	transperline = DIV_ROUND_UP(transperline, divisor);
 
 	for (i = 0, yield = yieldlines; i < linestotrans; i++)
 	{
diff --git a/drivers/media/video/uvc/uvc_video.c b/drivers/media/video/uvc/uvc_video.c
index 6854ac7..03dc3a5 100644
--- a/drivers/media/video/uvc/uvc_video.c
+++ b/drivers/media/video/uvc/uvc_video.c
@@ -655,7 +655,7 @@ static int uvc_init_video_isoc(struct uvc_video_device *video,
 	if (size > UVC_MAX_FRAME_SIZE)
 		return -EINVAL;
 
-	npackets = (size + psize - 1) / psize;
+	npackets = DIV_ROUND_UP(size, psize);
 	if (npackets > UVC_MAX_ISO_PACKETS)
 		npackets = UVC_MAX_ISO_PACKETS;
 
diff --git a/drivers/media/video/zoran_device.c b/drivers/media/video/zoran_device.c
index 88d3697..2b3ca14 100644
--- a/drivers/media/video/zoran_device.c
+++ b/drivers/media/video/zoran_device.c
@@ -377,7 +377,7 @@ zr36057_set_vfe (struct zoran              *zr,
 
 	/* horizontal */
 	VidWinWid = video_width;
-	X = (VidWinWid * 64 + tvn->Wa - 1) / tvn->Wa;
+	X = DIV_ROUND_UP(VidWinWid * 64, tvn->Wa);
 	We = (VidWinWid * 64) / X;
 	HorDcm = 64 - X;
 	hcrop1 = 2 * ((tvn->Wa - We) / 4);
@@ -403,7 +403,7 @@ zr36057_set_vfe (struct zoran              *zr,
 	/* Vertical */
 	DispMode = !(video_height > BUZ_MAX_HEIGHT / 2);
 	VidWinHt = DispMode ? video_height : video_height / 2;
-	Y = (VidWinHt * 64 * 2 + tvn->Ha - 1) / tvn->Ha;
+	Y = DIV_ROUND_UP(VidWinHt * 64 * 2, tvn->Ha);
 	He = (VidWinHt * 64) / Y;
 	VerDcm = 64 - Y;
 	vcrop1 = (tvn->Ha / 2 - He) / 2;

qlambert