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/delay.h>
  79
  80                         typedef uint8_t uint_reg_t;
  81
  82                         #define ARCH_HAS_EEPROM_ADDRESS_SPACE
  83                         #define ARCH_HAS_FLASH_ADDRESS_SPACE
  84                         #define ARCH_HAS_MULTI_ADDRESS_SPACE
  85                         #define ARCH_LITTLE_ENDIAN
  86
  87                         #include "Endianness.h"
  88                 #elif (ARCH == ARCH_UC3)
  89                         #include <avr32/io.h>
  90
  91                         // === TODO: Find abstracted way to handle these ===
  92                         #define PROGMEM                  const
  93                         #define pgm_read_byte(x)         *x
  94                         #define memcmp_P(...)            memcmp(__VA_ARGS__)
  95                         #define memcpy_P(...)            memcpy(__VA_ARGS__)
  96                         // ==================================================
  97
  98                         typedef uint32_t uint_reg_t;
  99
 100                         #define  ARCH_BIG_ENDIAN
 101
 102                         #include "Endianness.h"
 103                 #else
 104                         #error Unknown device architecture specified.
 105                 #endif
 106
 107         /* Public Interface - May be used in end-application: */
 108                 /* Macros: */
 109                         /** Macro for encasing other multi-statement macros. This should be used along with an opening brace
 110                          *  before the start of any multi-statement macro, so that the macros contents as a whole are treated
 111                          *  as a discrete block and not as a list of separate statements which may cause problems when used as
 112                          *  a block (such as inline \c if statements).
 113                          */
 114                         #define MACROS                  do
 115
 116                         /** Macro for encasing other multi-statement macros. This should be used along with a preceding closing
 117                          *  brace at the end of any multi-statement macro, so that the macros contents as a whole are treated
 118                          *  as a discrete block and not as a list of separate statements which may cause problems when used as
 119                          *  a block (such as inline \c if statements).
 120                          */
 121                         #define MACROE                  while (0)
 122
 123                         /** Convenience macro to determine the larger of two values.
 124                          *
 125                          *  \note This macro should only be used with operands that do not have side effects from being evaluated
 126                          *        multiple times.
 127                          *
 128                          *  \param[in] x  First value to compare
 129                          *  \param[in] y  First value to compare
 130                          *
 131                          *  \return The larger of the two input parameters
 132                          */
 133                         #if !defined(MAX) || defined(__DOXYGEN__)
 134                                 #define MAX(x, y)               ((x > y) ? x : y)
 135                         #endif
 136
 137                         /** Convenience macro to determine the smaller of two values.
 138                          *
 139                          *  \note This macro should only be used with operands that do not have side effects from being evaluated
 140                          *        multiple times.
 141                          *
 142                          *  \param[in] x  First value to compare
 143                          *  \param[in] y  First value to compare
 144                          *
 145                          *  \return The smaller of the two input parameters
 146                          */
 147                         #if !defined(MIN) || defined(__DOXYGEN__)
 148                                 #define MIN(x, y)               ((x < y) ? x : y)
 149                         #endif
 150
 151                         #if (ARCH == ARCH_AVR8) || defined(__DOXYGEN__)
 152                                 /** Defines a volatile \c NOP statement which cannot be optimized out by the compiler, and thus can always
 153                                  *  be set as a breakpoint in the resulting code. Useful for debugging purposes, where the optimiser
 154                                  *  removes/reorders code to the point where break points cannot reliably be set.
 155                                  *
 156                                  *  \ingroup Group_Debugging
 157                                  */
 158                                 #define JTAG_DEBUG_POINT()      __asm__ __volatile__ ("NOP" ::)
 159
 160                                 /** Defines an explicit JTAG break point in the resulting binary via the assembly \c BREAK statement. When
 161                                  *  a JTAG is used, this causes the program execution to halt when reached until manually resumed.
 162                                  *
 163                                  *  \ingroup Group_Debugging
 164                                  */
 165                                 #define JTAG_DEBUG_BREAK()      __asm__ __volatile__ ("BREAK" ::)
 166
 167                                 #if !defined(pgm_read_ptr) || defined(__DOXYGEN__)
 168                                         /** Reads a pointer out of PROGMEM space on the AVR8 architecture. This is currently a wrapper for the
 169                                          *  avr-libc \c pgm_read_ptr() macro with a \c void* cast, so that its value can be assigned directly
 170                                          *  to a pointer variable or used in pointer arithmetic without further casting in C. In a future
 171                                          *  avr-libc distribution this will be part of the standard API and will be implemented in a more formal
 172                                          *  manner.
 173                                          *
 174                                          *  \param[in] Addr  Address of the pointer to read.
 175                                          *
 176                                          *  \return Pointer retrieved from PROGMEM space.
 177                                          */
 178                                         #define pgm_read_ptr(Addr)    (void*)pgm_read_word(Addr)
 179                                 #endif
 180
 181                                 /** Macro for testing condition "x" and breaking via \ref JTAG_DEBUG_BREAK() if the condition is false.
 182                                  *
 183                                  *  \param[in] Condition  Condition that will be evaluated,
 184                                  *
 185                                  *  \ingroup Group_Debugging
 186                                 */
 187                                 #define JTAG_DEBUG_ASSERT(Condition)    MACROS{ if (!(Condition)) { JTAG_DEBUG_BREAK(); } }MACROE
 188
 189                                 /** Macro for testing condition "x" and writing debug data to the stdout stream if \c false. The stdout stream
 190                                  *  must be pre-initialized before this macro is run and linked to an output device, such as the microcontroller's
 191                                  *  USART peripheral.
 192                                  *
 193                                  *  The output takes the form "{FILENAME}: Function {FUNCTION NAME}, Line {LINE NUMBER}: Assertion {Condition} failed."
 194                                  *
 195                                  *  \param[in] Condition  Condition that will be evaluated,
 196                                  *
 197                                  *  \ingroup Group_Debugging
 198                                  */
 199                                 #define STDOUT_ASSERT(Condition)        MACROS{ if (!(x)) { printf_P(PSTR("%s: Function \"%s\", Line %d: "   \
 200                                                                                 "Assertion \"%s\" failed.\r\n"),     \
 201                                                                                 __FILE__, __func__, __LINE__, #Condition); } }MACROE
 202                         #endif
 203
 204                         /** Forces GCC to use pointer indirection (via the device's pointer register pairs) when accessing the given
 205                          *  struct pointer. In some cases GCC will emit non-optimal assembly code when accessing a structure through
 206                          *  a pointer, resulting in a larger binary. When this macro is used on a (non \c const) structure pointer before
 207                          *  use, it will force GCC to use pointer indirection on the elements rather than direct store and load
 208                          *  instructions.
 209                          *
 210                          *  \param[in, out] StructPtr  Pointer to a structure which is to be forced into indirect access mode.
 211                          */
 212                         #define GCC_FORCE_POINTER_ACCESS(StructPtr) __asm__ __volatile__("" : "=b" (StructPtr) : "0" (StructPtr))
 213
 214                         /** Forces GCC to create a memory barrier, ensuring that memory accesses are not reordered past the barrier point.
 215                          *  This can be used before ordering-critical operations, to ensure that the compiler does not re-order the resulting
 216                          *  assembly output in an unexpected manner on sections of code that are ordering-specific.
 217                          */
 218                         #define GCC_MEMORY_BARRIER()                __asm__ __volatile__("" ::: "memory");
 219
 220                 /* Inline Functions: */
 221                         /** Function to reverse the individual bits in a byte - i.e. bit 7 is moved to bit 0, bit 6 to bit 1,
 222                          *  etc.
 223                          *
 224                          *  \param[in] Byte  Byte of data whose bits are to be reversed.
 225                          */
 226                         static inline uint8_t BitReverse(uint8_t Byte) ATTR_WARN_UNUSED_RESULT ATTR_CONST;
 227                         static inline uint8_t BitReverse(uint8_t Byte)
 228                         {
 229                                 Byte = (((Byte & 0xF0) >> 4) | ((Byte & 0x0F) << 4));
 230                                 Byte = (((Byte & 0xCC) >> 2) | ((Byte & 0x33) << 2));
 231                                 Byte = (((Byte & 0xAA) >> 1) | ((Byte & 0x55) << 1));
 232
 233                                 return Byte;
 234                         }
 235
 236                         /** Function to perform a blocking delay for a specified number of milliseconds. The actual delay will be
 237                          *  at a minimum the specified number of milliseconds, however due to loop overhead and internal calculations
 238                          *  may be slightly higher.
 239                          *
 240                          *  \param[in] Milliseconds  Number of milliseconds to delay
 241                          */
 242                         static inline void Delay_MS(uint8_t Milliseconds)
 243                         {
 244                                 #if (ARCH == ARCH_AVR8)
 245                                 if (__builtin_constant_p(Milliseconds))
 246                                 {
 247                                         _delay_ms(Milliseconds);
 248                                 }
 249                                 else
 250                                 {
 251                                         while (Milliseconds--)
 252                                           _delay_ms(1);
 253                                 }
 254                                 #elif (ARCH == ARCH_UC3)
 255                                 while (Milliseconds--)
 256                                 {
 257                                         __builtin_mtsr(AVR32_COUNT, 0);
 258                                         while (__builtin_mfsr(AVR32_COUNT) < (F_CPU / 1000));
 259                                 }
 260                                 #endif
 261                         }
 262
 263 #endif
 264
 265 /** @} */
 266