diff options
| -rw-r--r-- | drivers/media/video/bt8xx/bttvp.h | 2 | ||||
| -rw-r--r-- | drivers/media/video/usbvideo/vicam.c | 6 | ||||
| -rw-r--r-- | include/linux/kernel.h | 91 |
3 files changed, 74 insertions, 25 deletions
diff --git a/drivers/media/video/bt8xx/bttvp.h b/drivers/media/video/bt8xx/bttvp.h index 03816b73f847..27da7b423275 100644 --- a/drivers/media/video/bt8xx/bttvp.h +++ b/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/drivers/media/video/usbvideo/vicam.c b/drivers/media/video/usbvideo/vicam.c index 64819353276a..17f542dfb366 100644 --- a/drivers/media/video/usbvideo/vicam.c +++ b/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/include/linux/kernel.h b/include/linux/kernel.h index 53839ba265ec..4d46e299afb5 100644 --- a/include/linux/kernel.h +++ b/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 |