From 11d237ea0948c4d235fa311b2f13871e0407b28b Mon Sep 17 00:00:00 2001
From: Harvey Harrison <harvey.harrison@gmail.com>
Date: Wed, 30 Apr 2008 00:54:55 -0700
Subject: [PATCH] --- yaml --- r: 95287 b: refs/heads/master c:
 bdf4bbaaee3d4b8f555658333cbce1affe9070fb h: refs/heads/master i:   95285:
 447707fd03e401ee2d348cd1b3db3afdc60ae06f   95283:
 5326ff57d6a8b9fef46e9226828ca5fe3c7217ca   95279:
 defc5078b6e59ac742e12bfcba5dfff8b64954b6 v: v3

---
 [refs]                                     |  2 +-
 trunk/drivers/media/video/bt8xx/bttvp.h    |  2 -
 trunk/drivers/media/video/usbvideo/vicam.c |  6 --
 trunk/include/linux/kernel.h               | 91 ++++++++++++++++++----
 4 files changed, 75 insertions(+), 26 deletions(-)

diff --git a/[refs] b/[refs]
index d3dcc6e23161..c8b5e7da42a4 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 354a1f4d99240f53980275416ca3e1ac2ee73d5d
+refs/heads/master: bdf4bbaaee3d4b8f555658333cbce1affe9070fb
diff --git a/trunk/drivers/media/video/bt8xx/bttvp.h b/trunk/drivers/media/video/bt8xx/bttvp.h
index 03816b73f847..27da7b423275 100644
--- a/trunk/drivers/media/video/bt8xx/bttvp.h
+++ b/trunk/drivers/media/video/bt8xx/bttvp.h
@@ -81,8 +81,6 @@
 /* Limits scaled width, which must be a multiple of 4. */
 #define MAX_HACTIVE (0x3FF & -4)
 
-#define clamp(x, low, high) min (max (low, x), high)
-
 #define BTTV_NORMS    (\
 		V4L2_STD_PAL    | V4L2_STD_PAL_N | \
 		V4L2_STD_PAL_Nc | V4L2_STD_SECAM | \
diff --git a/trunk/drivers/media/video/usbvideo/vicam.c b/trunk/drivers/media/video/usbvideo/vicam.c
index 64819353276a..17f542dfb366 100644
--- a/trunk/drivers/media/video/usbvideo/vicam.c
+++ b/trunk/drivers/media/video/usbvideo/vicam.c
@@ -70,12 +70,6 @@
 
 #define VICAM_HEADER_SIZE       64
 
-#define clamp( x, l, h )        max_t( __typeof__( x ),         \
-				       ( l ),                   \
-				       min_t( __typeof__( x ),  \
-					      ( h ),            \
-					      ( x ) ) )
-
 /* Not sure what all the bytes in these char
  * arrays do, but they're necessary to make
  * the camera work.
diff --git a/trunk/include/linux/kernel.h b/trunk/include/linux/kernel.h
index 53839ba265ec..4d46e299afb5 100644
--- a/trunk/include/linux/kernel.h
+++ b/trunk/include/linux/kernel.h
@@ -338,33 +338,90 @@ extern void print_hex_dump_bytes(const char *prefix_str, int prefix_type,
 #endif /* __LITTLE_ENDIAN */
 
 /*
- * min()/max() macros that also do
+ * min()/max()/clamp() macros that also do
  * strict type-checking.. See the
  * "unnecessary" pointer comparison.
  */
-#define min(x,y) ({ \
-	typeof(x) _x = (x);	\
-	typeof(y) _y = (y);	\
-	(void) (&_x == &_y);		\
-	_x < _y ? _x : _y; })
-
-#define max(x,y) ({ \
-	typeof(x) _x = (x);	\
-	typeof(y) _y = (y);	\
-	(void) (&_x == &_y);		\
-	_x > _y ? _x : _y; })
+#define min(x, y) ({				\
+	typeof(x) _min1 = (x);			\
+	typeof(y) _min2 = (y);			\
+	(void) (&_min1 == &_min2);		\
+	_min1 < _min2 ? _min1 : _min2; })
+
+#define max(x, y) ({				\
+	typeof(x) _max1 = (x);			\
+	typeof(y) _max2 = (y);			\
+	(void) (&_max1 == &_max2);		\
+	_max1 > _max2 ? _max1 : _max2; })
+
+/**
+ * clamp - return a value clamped to a given range with strict typechecking
+ * @val: current value
+ * @min: minimum allowable value
+ * @max: maximum allowable value
+ *
+ * This macro does strict typechecking of min/max to make sure they are of the
+ * same type as val.  See the unnecessary pointer comparisons.
+ */
+#define clamp(val, min, max) ({			\
+	typeof(val) __val = (val);		\
+	typeof(min) __min = (min);		\
+	typeof(max) __max = (max);		\
+	(void) (&__val == &__min);		\
+	(void) (&__val == &__max);		\
+	__val = __val < __min ? __min: __val;	\
+	__val > __max ? __max: __val; })
 
 /*
  * ..and if you can't take the strict
  * types, you can specify one yourself.
  *
- * Or not use min/max at all, of course.
+ * Or not use min/max/clamp at all, of course.
+ */
+#define min_t(type, x, y) ({			\
+	type __min1 = (x);			\
+	type __min2 = (y);			\
+	__min1 < __min2 ? __min1: __min2; })
+
+#define max_t(type, x, y) ({			\
+	type __max1 = (x);			\
+	type __max2 = (y);			\
+	__max1 > __max2 ? __max1: __max2; })
+
+/**
+ * clamp_t - return a value clamped to a given range using a given type
+ * @type: the type of variable to use
+ * @val: current value
+ * @min: minimum allowable value
+ * @max: maximum allowable value
+ *
+ * This macro does no typechecking and uses temporary variables of type
+ * 'type' to make all the comparisons.
  */
-#define min_t(type,x,y) \
-	({ type __x = (x); type __y = (y); __x < __y ? __x: __y; })
-#define max_t(type,x,y) \
-	({ type __x = (x); type __y = (y); __x > __y ? __x: __y; })
+#define clamp_t(type, val, min, max) ({		\
+	type __val = (val);			\
+	type __min = (min);			\
+	type __max = (max);			\
+	__val = __val < __min ? __min: __val;	\
+	__val > __max ? __max: __val; })
 
+/**
+ * clamp_val - return a value clamped to a given range using val's type
+ * @val: current value
+ * @min: minimum allowable value
+ * @max: maximum allowable value
+ *
+ * This macro does no typechecking and uses temporary variables of whatever
+ * type the input argument 'val' is.  This is useful when val is an unsigned
+ * type and min and max are literals that will otherwise be assigned a signed
+ * integer type.
+ */
+#define clamp_val(val, min, max) ({		\
+	typeof(val) __val = (val);		\
+	typeof(val) __min = (min);		\
+	typeof(val) __max = (max);		\
+	__val = __val < __min ? __min: __val;	\
+	__val > __max ? __max: __val; })
 
 /**
  * container_of - cast a member of a structure out to the containing structure