include/util.h File Reference

Misc utility functions and definitions. More...

#include <types.h>

Include dependency graph for util.h:

This graph shows which files directly or indirectly include this file:

Go to the source code of this file.

Defines

#define xstr(s)   str(s)
 Stringify the result after expansion of a macro argument.
#define str(s)   #s
 Stringify a macro argument without expansion.
#define ARRAY_LEN(a)   (sizeof(a) / sizeof((a)[0]))
 Get the number of elements in array a.
#define container_of(ptr, type, member)   ((type *)((unsigned long)(ptr) - offsetof(type, member)))
 Get the containing object.
#define div_ceil(a, b)   (((a) + (b) - 1) / (b))
 Calculate $ \left\lceil \frac{a}{b} \right\rceil $ using integer arithmetic.

Functions

static int isdigit (int c)
 Determine whether or not the character c is a digit.
static int iscntrl (int c)
 Determine whether or not the character c is a control character.
static int isspace (int c)
 Determine whether or not the character c is a space.
int ilog2_undefined (void)
static int ilog2 (unsigned int x)
 Calculate the base-2 logarithm of a number rounded down to the nearest integer.
static bool is_power_of_two (unsigned long x)
 Test if a given value is a power of two.
static unsigned long round_down (unsigned long x, unsigned int order)
 Round down to the nearest power of two boundary.
static unsigned long round_up (unsigned long x, unsigned int order)
 Round up to the nearest power of two boundary.
static unsigned long word_align (unsigned long x)
 Round up to the nearest word-aligned boundary.

Detailed Description

Misc utility functions and definitions.

Author:
Atmel Corporation: http://www.atmel.com
Support and FAQ: http://support.atmel.no/

Definition in file util.h.

Define Documentation

#define ARRAY_LEN ( a   )     (sizeof(a) / sizeof((a)[0]))

Get the number of elements in array a.

Definition at line 59 of file util.h.

Referenced by softirq_priv_do_pending(), and softirq_set_handler().

#define container_of ( ptr,
type,
member   )     ((type *)((unsigned long)(ptr) - offsetof(type, member)))

Get the containing object.

Parameters:
ptr Pointer to the contained object.
type Type of the containing object.
member Member name of the contained object inside the containing object.
Returns:
Pointer to the containing object.

Definition at line 111 of file util.h.

Referenced by pdca_channel_of(), and sdmmc_card_get_slot().

#define div_ceil ( a,
b   )     (((a) + (b) - 1) / (b))

Calculate $ \left\lceil \frac{a}{b} \right\rceil $ using integer arithmetic.

Parameters:
a An integer
b Another integer
Returns:
(a / b) rounded up to the nearest integer.

Definition at line 237 of file util.h.

Referenced by ns2cyc(), and udelay().

#define str ( s   )     #s

Stringify a macro argument without expansion.

Definition at line 54 of file util.h.

#define xstr ( s   )     str(s)

Stringify the result after expansion of a macro argument.

Definition at line 49 of file util.h.

Function Documentation

static int ilog2 ( unsigned int  x  )  [inline, static]

Calculate the base-2 logarithm of a number rounded down to the nearest integer.

Parameters:
x A 32-bit value
Returns:
The base-2 logarithm of x, or -1 if x is 0.

Definition at line 128 of file util.h.

References count_leading_zeroes, ilog2_undefined(), and is_constant.

Referenced by usbb_udc_configure_ep(), and watchdog_set_timeout().

Here is the call graph for this function:

int ilog2_undefined ( void   ) 

For internal use only.

Undefined function. Will cause a link failure if ilog2() is called with an invalid constant value.

Referenced by ilog2().

static bool is_power_of_two ( unsigned long  x  )  [inline, static]

Test if a given value is a power of two.

Parameters:
x The value to test
Returns:
true if x is a power of two, false otherwise

Definition at line 174 of file util.h.

static int iscntrl ( int  c  )  [inline, static]

Determine whether or not the character c is a control character.

Parameters:
c The character to consider.
Return values:
0 The character c is not a control character.
1 The character c is a control character.

Definition at line 81 of file util.h.

static int isdigit ( int  c  )  [inline, static]

Determine whether or not the character c is a digit.

Parameters:
c The character to consider.
Return values:
0 The character c is not a digit.
1 The character c is a digit.

Definition at line 68 of file util.h.

Referenced by console_vprintf().

static int isspace ( int  c  )  [inline, static]

Determine whether or not the character c is a space.

Note:
This implementation is very limited in that it doesn't consider a bunch of control characters that probably should be interpreted as space.
Parameters:
c The character to consider.
Return values:
0 The character c is not a space.
1 The character c is a space.

Definition at line 97 of file util.h.

static unsigned long round_down ( unsigned long  x,
unsigned int  order 
) [inline, static]

Round down to the nearest power of two boundary.

Parameters:
x A positive integer
order log2 of the required boundary.
Returns:
x rounded down to the nearest multiple of (1 << order)

Definition at line 186 of file util.h.

Referenced by physmem_alloc(), and round_up().

static unsigned long round_up ( unsigned long  x,
unsigned int  order 
) [inline, static]

Round up to the nearest power of two boundary.

Parameters:
x A positive integer
order log2 of the required boundary.
Returns:
x rounded up to the next multiple of (1 << order)

Definition at line 198 of file util.h.

References round_down().

Referenced by dma_pool_init_coherent_physmem(), mem_pool_init(), mem_pool_init_physmem(), physmem_alloc_low(), and word_align().

Here is the call graph for this function:

static unsigned long word_align ( unsigned long  x  )  [inline, static]

Round up to the nearest word-aligned boundary.

Parameters:
x Address or offset to be word-aligned
Returns:
The smallest number y where y >= x and y & 3 == 0.

Definition at line 209 of file util.h.

References round_up().

Here is the call graph for this function:

Generated on Tue Sep 15 10:22:06 2009 for libavr32 by  doxygen 1.5.8