LUFA/Common/Common.h

   1 /*
   2              LUFA Library
   3      Copyright (C) Dean Camera, 2011.
   4
   5   dean [at] fourwalledcubicle [dot] com
   6            www.lufa-lib.org
   7 */
   8
   9 /*
  10   Copyright 2011  Dean Camera (dean [at] fourwalledcubicle [dot] com)
  11
  12   Permission to use, copy, modify, distribute, and sell this
  13   software and its documentation for any purpose is hereby granted
  14   without fee, provided that the above copyright notice appear in
  15   all copies and that both that the copyright notice and this
  16   permission notice and warranty disclaimer appear in supporting
  17   documentation, and that the name of the author not be used in
  18   advertising or publicity pertaining to distribution of the
  19   software without specific, written prior permission.
  20
  21   The author disclaim all warranties with regard to this
  22   software, including all implied warranties of merchantability
  23   and fitness.  In no event shall the author be liable for any
  24   special, indirect or consequential damages or any damages
  25   whatsoever resulting from loss of use, data or profits, whether
  26   in an action of contract, negligence or other tortious action,
  27   arising out of or in connection with the use or performance of
  28   this software.
  29 */
  30
  31 /** \file
  32  *  \brief Common library convenience headers, macros and functions.
  33  *
  34  *  \copydetails Group_Common
  35  */
  36
  37 /** \defgroup Group_Common Common Utility Headers - LUFA/Drivers/Common/Common.h
  38  *  \brief Common library convenience headers, macros and functions.
  39  *
  40  *  Common utility headers containing macros, functions, enums and types which are common to all
  41  *  aspects of the library.
  42  *
  43  *  @{
  44  */
  45
  46 /** \defgroup Group_Debugging Debugging Macros
  47  *  \brief Convenience macros to aid in debugging applications.
  48  *
  49  *  Macros to aid debugging of a user application.
  50  */
  51
  52 #ifndef __LUFA_COMMON_H__
  53 #define __LUFA_COMMON_H__
  54
  55         /* Macros: */
  56                 #define __INCLUDE_FROM_COMMON_H
  57
  58         /* Includes: */
  59                 #include <stdint.h>
  60                 #include <stdbool.h>
  61                 #include <string.h>
  62                 #include <stddef.h>
  63
  64                 #include "Architectures.h"
  65                 #include "Attributes.h"
  66                 #include "BoardTypes.h"
  67
  68         /* Architecture specific utility includes: */
  69                 #if defined(__DOXYGEN__)
  70                         /** Type define for an unsigned integer the same width as the selected architecture's machine register. */
  71                         typedef MACHINE_REG_t uint_reg_t;
  72                 #elif (ARCH == ARCH_AVR8)
  73                         #include <avr/io.h>
  74                         #include <avr/interrupt.h>
  75                         #include <avr/pgmspace.h>
  76                         #include <avr/eeprom.h>
  77                         #include <avr/boot.h>
  78                         #include <util/atomic.h>
  79                         #include <util/delay.h>
  80
  81                         typedef uint8_t uint_reg_t;
  82
  83                         #define  ARCH_LITTLE_ENDIAN
  84                         #include "Endianness.h"
  85                 #elif (ARCH == ARCH_UC3)
  86                         #include <avr32/io.h>
  87
  88                         // === TODO: Find abstracted way to handle these ===
  89                         #define ISR(Name)                void Name (void) __attribute__((__interrupt__)); void Name (void)
  90                         #define PROGMEM                  const
  91                         #define ATOMIC_BLOCK(x)          if (1)
  92                         #define ATOMIC_RESTORESTATE
  93                         #define pgm_read_byte(x)         *x
  94                         #define _delay_ms(x)
  95                         #define memcmp_P(...)            memcmp(__VA_ARGS__)
  96                         #define memcpy_P(...)            memcpy(__VA_ARGS__)
  97                         #define USE_RAM_DESCRIPTORS
  98                         // ==================================================
  99
 100                         typedef uint32_t uint_reg_t;
 101
 102                         #define  ARCH_BIG_ENDIAN
 103                         #include "Endianness.h"
 104                 #else
 105                         #error Unknown device architecture specified.
 106                 #endif
 107
 108         /* Public Interface - May be used in end-application: */
 109                 /* Macros: */
 110                         /** Macro for encasing other multi-statement macros. This should be used along with an opening brace
 111                          *  before the start of any multi-statement macro, so that the macros contents as a whole are treated
 112                          *  as a discrete block and not as a list of separate statements which may cause problems when used as
 113                          *  a block (such as inline \c if statements).
 114                          */
 115                         #define MACROS                  do
 116
 117                         /** Macro for encasing other multi-statement macros. This should be used along with a preceding closing
 118                          *  brace at the end of any multi-statement macro, so that the macros contents as a whole are treated
 119                          *  as a discrete block and not as a list of separate statements which may cause problems when used as
 120                          *  a block (such as inline \c if statements).
 121                          */
 122                         #define MACROE                  while (0)
 123
 124                         /** Convenience macro to determine the larger of two values.
 125                          *
 126                          *  \note This macro should only be used with operands that do not have side effects from being evaluated
 127                          *        multiple times.
 128                          *
 129                          *  \param[in] x  First value to compare
 130                          *  \param[in] y  First value to compare
 131                          *
 132                          *  \return The larger of the two input parameters
 133                          */
 134                         #if !defined(MAX) || defined(__DOXYGEN__)
 135                                 #define MAX(x, y)               ((x > y) ? x : y)
 136                         #endif
 137
 138                         /** Convenience macro to determine the smaller of two values.
 139                          *
 140                          *  \note This macro should only be used with operands that do not have side effects from being evaluated
 141                          *        multiple times.
 142                          *
 143                          *  \param[in] x  First value to compare
 144                          *  \param[in] y  First value to compare
 145                          *
 146                          *  \return The smaller of the two input parameters
 147                          */
 148                         #if !defined(MIN) || defined(__DOXYGEN__)
 149                                 #define MIN(x, y)               ((x < y) ? x : y)
 150                         #endif
 151
 152                         #if (ARCH == ARCH_AVR8) || defined(__DOXYGEN__)
 153                                 /** Defines a volatile \c NOP statement which cannot be optimized out by the compiler, and thus can always
 154                                  *  be set as a breakpoint in the resulting code. Useful for debugging purposes, where the optimiser
 155                                  *  removes/reorders code to the point where break points cannot reliably be set.
 156                                  *
 157                                  *  \ingroup Group_Debugging
 158                                  */
 159                                 #define JTAG_DEBUG_POINT()      __asm__ __volatile__ ("NOP" ::)
 160
 161                                 /** Defines an explicit JTAG break point in the resulting binary via the assembly \c BREAK statement. When
 162                                  *  a JTAG is used, this causes the program execution to halt when reached until manually resumed.
 163                                  *
 164                                  *  \ingroup Group_Debugging
 165                                  */
 166                                 #define JTAG_DEBUG_BREAK()      __asm__ __volatile__ ("BREAK" ::)
 167
 168                                 #if !defined(pgm_read_ptr) || defined(__DOXYGEN__)
 169                                         /** Reads a pointer out of PROGMEM space on the AVR8 architecture. This is currently a wrapper for the
 170                                          *  avr-libc \c pgm_read_ptr() macro with a \c void* cast, so that its value can be assigned directly
 171                                          *  to a pointer variable or used in pointer arithmetic without further casting in C. In a future
 172                                          *  avr-libc distribution this will be part of the standard API and will be implemented in a more formal
 173                                          *  manner.
 174                                          *
 175                                          *  \param[in] Addr  Address of the pointer to read.
 176                                          *
 177                                          *  \return Pointer retrieved from PROGMEM space.
 178                                          */
 179                                         #define pgm_read_ptr(Addr)    (void*)pgm_read_word(Addr)
 180                                 #endif
 181
 182                                 /** Macro for testing condition "x" and breaking via \ref JTAG_DEBUG_BREAK() if the condition is false.
 183                                  *
 184                                  *  \param[in] Condition  Condition that will be evaluated,
 185                                  *
 186                                  *  \ingroup Group_Debugging
 187                                 */
 188                                 #define JTAG_DEBUG_ASSERT(Condition)    MACROS{ if (!(Condition)) { JTAG_DEBUG_BREAK(); } }MACROE
 189
 190                                 /** Macro for testing condition "x" and writing debug data to the stdout stream if \c false. The stdout stream
 191                                  *  must be pre-initialized before this macro is run and linked to an output device, such as the microcontroller's
 192                                  *  USART peripheral.
 193                                  *
 194                                  *  The output takes the form "{FILENAME}: Function {FUNCTION NAME}, Line {LINE NUMBER}: Assertion {Condition} failed."
 195                                  *
 196                                  *  \param[in] Condition  Condition that will be evaluated,
 197                                  *
 198                                  *  \ingroup Group_Debugging
 199                                  */
 200                                 #define STDOUT_ASSERT(Condition)        MACROS{ if (!(x)) { printf_P(PSTR("%s: Function \"%s\", Line %d: "   \
 201                                                                                 "Assertion \"%s\" failed.\r\n"),     \
 202                                                                                 __FILE__, __func__, __LINE__, #Condition); } }MACROE
 203                         #endif
 204
 205                         /** Forces GCC to use pointer indirection (via the device's pointer register pairs) when accessing the given
 206                          *  struct pointer. In some cases GCC will emit non-optimal assembly code when accessing a structure through
 207                          *  a pointer, resulting in a larger binary. When this macro is used on a (non \c const) structure pointer before
 208                          *  use, it will force GCC to use pointer indirection on the elements rather than direct store and load
 209                          *  instructions.
 210                          *
 211                          *  \param[in, out] StructPtr  Pointer to a structure which is to be forced into indirect access mode.
 212                          */
 213                         #define GCC_FORCE_POINTER_ACCESS(StructPtr) __asm__ __volatile__("" : "=b" (StructPtr) : "0" (StructPtr))
 214
 215                         /** Forces GCC to create a memory barrier, ensuring that memory accesses are not reordered past the barrier point.
 216                          *  This can be used before ordering-critical operations, to ensure that the compiler does not re-order the resulting
 217                          *  assembly output in an unexpected manner on sections of code that are ordering-specific.
 218                          */
 219                         #define GCC_MEMORY_BARRIER()                __asm__ __volatile__("" ::: "memory");
 220
 221                 /* Inline Functions: */
 222                         /** Function to reverse the individual bits in a byte - i.e. bit 7 is moved to bit 0, bit 6 to bit 1,
 223                          *  etc.
 224                          *
 225                          *  \param[in] Byte  Byte of data whose bits are to be reversed.
 226                          */
 227                         static inline uint8_t BitReverse(uint8_t Byte) ATTR_WARN_UNUSED_RESULT ATTR_CONST;
 228                         static inline uint8_t BitReverse(uint8_t Byte)
 229                         {
 230                                 Byte = (((Byte & 0xF0) >> 4) | ((Byte & 0x0F) << 4));
 231                                 Byte = (((Byte & 0xCC) >> 2) | ((Byte & 0x33) << 2));
 232                                 Byte = (((Byte & 0xAA) >> 1) | ((Byte & 0x55) << 1));
 233
 234                                 return Byte;
 235                         }
 236
 237 #endif
 238
 239 /** @} */
 240