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 /** \defgroup Group_BitManip Endian and Bit Macros
  53  *  \brief Convenience macros to aid in bit manipulations and endianness transforms.
  54  *
  55  *  Functions for swapping endianness and reversing bit orders of data.
  56  */
  57
  58 #ifndef __LUFA_COMMON_H__
  59 #define __LUFA_COMMON_H__
  60
  61         /* Macros: */
  62                 #if !defined(__DOXYGEN__)
  63                         #define __INCLUDE_FROM_COMMON_H
  64                 #endif
  65
  66         /* Includes: */
  67                 #include <stdint.h>
  68                 #include <stdbool.h>
  69                 #include <string.h>
  70                 #include <stddef.h>
  71
  72                 #include "Architectures.h"
  73                 #include "Attributes.h"
  74                 #include "BoardTypes.h"
  75
  76         /* Architecture specific utility includes: */
  77                 #if (ARCH == ARCH_AVR8)
  78                         #include <avr/io.h>
  79                         #include <avr/interrupt.h>
  80                         #include <avr/pgmspace.h>
  81                         #include <avr/eeprom.h>
  82                         #include <avr/boot.h>
  83                         #include <util/atomic.h>
  84                         #include <util/delay.h>
  85
  86                         typedef uint8_t uintN_t;
  87                         typedef int8_t  intN_t;
  88                 #elif (ARCH == ARCH_UC3B)
  89                         #include <avr32/io.h>
  90
  91                         typedef uint32_t uintN_t;
  92                         typedef int32_t  intN_t;
  93
  94                         #warning The UC3B architecture support is currently experimental and incomplete!
  95                 #endif
  96
  97         /* Public Interface - May be used in end-application: */
  98                 /* Macros: */
  99                         /** Macro for encasing other multi-statement macros. This should be used along with an opening brace
 100                          *  before the start of any multi-statement macro, so that the macros contents as a whole are treated
 101                          *  as a discrete block and not as a list of separate statements which may cause problems when used as
 102                          *  a block (such as inline \c if statements).
 103                          */
 104                         #define MACROS                  do
 105
 106                         /** Macro for encasing other multi-statement macros. This should be used along with a preceding closing
 107                          *  brace at the end of any multi-statement macro, so that the macros contents as a whole are treated
 108                          *  as a discrete block and not as a list of separate statements which may cause problems when used as
 109                          *  a block (such as inline \c if statements).
 110                          */
 111                         #define MACROE                  while (0)
 112
 113                         /** Convenience macro to determine the larger of two values.
 114                          *
 115                          *  \note This macro should only be used with operands that do not have side effects from being evaluated
 116                          *        multiple times.
 117                          *
 118                          *  \param[in] x  First value to compare
 119                          *  \param[in] y  First value to compare
 120                          *
 121                          *  \return The larger of the two input parameters
 122                          */
 123                         #if !defined(MAX) || defined(__DOXYGEN__)
 124                                 #define MAX(x, y)               ((x > y) ? x : y)
 125                         #endif
 126
 127                         /** Convenience macro to determine the smaller of two values.
 128                          *
 129                          *  \note This macro should only be used with operands that do not have side effects from being evaluated
 130                          *        multiple times.
 131                          *
 132                          *  \param[in] x  First value to compare
 133                          *  \param[in] y  First value to compare
 134                          *
 135                          *  \return The smaller of the two input parameters
 136                          */
 137                         #if !defined(MIN) || defined(__DOXYGEN__)
 138                                 #define MIN(x, y)               ((x < y) ? x : y)
 139                         #endif
 140
 141                         #if (ARCH == ARCH_AVR8) || defined(__DOXYGEN__)
 142                                 /** Defines a volatile \c NOP statement which cannot be optimized out by the compiler, and thus can always
 143                                  *  be set as a breakpoint in the resulting code. Useful for debugging purposes, where the optimiser
 144                                  *  removes/reorders code to the point where break points cannot reliably be set.
 145                                  *
 146                                  *  \ingroup Group_Debugging
 147                                  */
 148                                 #define JTAG_DEBUG_POINT()      __asm__ __volatile__ ("NOP" ::)
 149
 150                                 /** Defines an explicit JTAG break point in the resulting binary via the assembly \c BREAK statement. When
 151                                  *  a JTAG is used, this causes the program execution to halt when reached until manually resumed.
 152                                  *
 153                                  *  \ingroup Group_Debugging
 154                                  */
 155                                 #define JTAG_DEBUG_BREAK()      __asm__ __volatile__ ("BREAK" ::)
 156
 157                                 #if !defined(pgm_read_ptr) || defined(__DOXYGEN__)
 158                                         /** Reads a pointer out of PROGMEM space on the AVR8 architecture. This is currently a wrapper for the
 159                                          *  avr-libc \c pgm_read_ptr() macro with a \c void* cast, so that its value can be assigned directly
 160                                          *  to a pointer variable or used in pointer arithmetic without further casting in C. In a future
 161                                          *  avr-libc distribution this will be part of the standard API and will be implemented in a more formal
 162                                          *  manner.
 163                                          *
 164                                          *  \param[in] Addr  Address of the pointer to read.
 165                                          *
 166                                          *  \return Pointer retrieved from PROGMEM space.
 167                                          */
 168                                         #define pgm_read_ptr(Addr)    (void*)pgm_read_word(Addr)
 169                                 #endif
 170
 171                                 /** Macro for testing condition "x" and breaking via \ref JTAG_DEBUG_BREAK() if the condition is false.
 172                                  *
 173                                  *  \param[in] Condition  Condition that will be evaluated,
 174                                  *
 175                                  *  \ingroup Group_Debugging
 176                                 */
 177                                 #define JTAG_DEBUG_ASSERT(Condition)    MACROS{ if (!(Condition)) { JTAG_DEBUG_BREAK(); } }MACROE
 178
 179                                 /** Macro for testing condition "x" and writing debug data to the stdout stream if \c false. The stdout stream
 180                                  *  must be pre-initialized before this macro is run and linked to an output device, such as the microcontroller's
 181                                  *  USART peripheral.
 182                                  *
 183                                  *  The output takes the form "{FILENAME}: Function {FUNCTION NAME}, Line {LINE NUMBER}: Assertion {Condition} failed."
 184                                  *
 185                                  *  \param[in] Condition  Condition that will be evaluated,
 186                                  *
 187                                  *  \ingroup Group_Debugging
 188                                  */
 189                                 #define STDOUT_ASSERT(Condition)        MACROS{ if (!(x)) { printf_P(PSTR("%s: Function \"%s\", Line %d: "   \
 190                                                                                 "Assertion \"%s\" failed.\r\n"),     \
 191                                                                                 __FILE__, __func__, __LINE__, #Condition); } }MACROE
 192                         #endif
 193
 194                         /** Forces GCC to use pointer indirection (via the device's pointer register pairs) when accessing the given
 195                          *  struct pointer. In some cases GCC will emit non-optimal assembly code when accessing a structure through
 196                          *  a pointer, resulting in a larger binary. When this macro is used on a (non \c const) structure pointer before
 197                          *  use, it will force GCC to use pointer indirection on the elements rather than direct store and load
 198                          *  instructions.
 199                          *
 200                          *  \param[in, out] StructPtr  Pointer to a structure which is to be forced into indirect access mode.
 201                          */
 202                         #define GCC_FORCE_POINTER_ACCESS(StructPtr) __asm__ __volatile__("" : "=b" (StructPtr) : "0" (StructPtr))
 203
 204                         /** Swaps the byte ordering of a 16-bit value at compile time. Do not use this macro for swapping byte orderings
 205                          *  of dynamic values computed at runtime, use \ref SwapEndian_16() instead. The result of this macro can be used
 206                          *  inside struct or other variable initializers outside of a function, something that is not possible with the
 207                          *  inline function variant.
 208                          *
 209                          *  \param[in]  x  16-bit value whose byte ordering is to be swapped.
 210                          *
 211                          *  \return Input value with the byte ordering reversed.
 212                          */
 213                         #define SWAPENDIAN_16(x)          ((((x) & 0xFF00) >> 8) | (((x) & 0x00FF) << 8))
 214
 215                         /** Swaps the byte ordering of a 32-bit value at compile time. Do not use this macro for swapping byte orderings
 216                          *  of dynamic values computed at runtime- use \ref SwapEndian_32() instead. The result of this macro can be used
 217                          *  inside struct or other variable initializers outside of a function, something that is not possible with the
 218                          *  inline function variant.
 219                          *
 220                          *  \param[in]  x  32-bit value whose byte ordering is to be swapped.
 221                          *
 222                          *  \return Input value with the byte ordering reversed.
 223                          */
 224                         #define SWAPENDIAN_32(x)          ((((x) & 0xFF000000UL) >> 24UL) | (((x) & 0x00FF0000UL) >> 8UL) | \
 225                                                            (((x) & 0x0000FF00UL) << 8UL)  | (((x) & 0x000000FFUL) << 24UL))
 226
 227                 /* Inline Functions: */
 228                         /** Function to reverse the individual bits in a byte - i.e. bit 7 is moved to bit 0, bit 6 to bit 1,
 229                          *  etc.
 230                          *
 231                          *  \ingroup Group_BitManip
 232                          *
 233                          *  \param[in] Byte  Byte of data whose bits are to be reversed.
 234                          */
 235                         static inline uint8_t BitReverse(uint8_t Byte) ATTR_WARN_UNUSED_RESULT ATTR_CONST;
 236                         static inline uint8_t BitReverse(uint8_t Byte)
 237                         {
 238                                 Byte = (((Byte & 0xF0) >> 4) | ((Byte & 0x0F) << 4));
 239                                 Byte = (((Byte & 0xCC) >> 2) | ((Byte & 0x33) << 2));
 240                                 Byte = (((Byte & 0xAA) >> 1) | ((Byte & 0x55) << 1));
 241
 242                                 return Byte;
 243                         }
 244
 245                         /** Function to reverse the byte ordering of the individual bytes in a 16 bit number.
 246                          *
 247                          *  \ingroup Group_BitManip
 248                          *
 249                          *  \param[in] Word  Word of data whose bytes are to be swapped.
 250                          */
 251                         static inline uint16_t SwapEndian_16(const uint16_t Word) ATTR_WARN_UNUSED_RESULT ATTR_CONST;
 252                         static inline uint16_t SwapEndian_16(const uint16_t Word)
 253                         {
 254                                 uint8_t Temp;
 255
 256                                 union
 257                                 {
 258                                         uint16_t Word;
 259                                         uint8_t  Bytes[2];
 260                                 } Data;
 261
 262                                 Data.Word = Word;
 263
 264                                 Temp = Data.Bytes[0];
 265                                 Data.Bytes[0] = Data.Bytes[1];
 266                                 Data.Bytes[1] = Temp;
 267
 268                                 return Data.Word;
 269                         }
 270
 271                         /** Function to reverse the byte ordering of the individual bytes in a 32 bit number.
 272                          *
 273                          *  \ingroup Group_BitManip
 274                          *
 275                          *  \param[in] DWord  Double word of data whose bytes are to be swapped.
 276                          */
 277                         static inline uint32_t SwapEndian_32(const uint32_t DWord) ATTR_WARN_UNUSED_RESULT ATTR_CONST;
 278                         static inline uint32_t SwapEndian_32(const uint32_t DWord)
 279                         {
 280                                 uint8_t Temp;
 281
 282                                 union
 283                                 {
 284                                         uint32_t DWord;
 285                                         uint8_t  Bytes[4];
 286                                 } Data;
 287
 288                                 Data.DWord = DWord;
 289
 290                                 Temp = Data.Bytes[0];
 291                                 Data.Bytes[0] = Data.Bytes[3];
 292                                 Data.Bytes[3] = Temp;
 293
 294                                 Temp = Data.Bytes[1];
 295                                 Data.Bytes[1] = Data.Bytes[2];
 296                                 Data.Bytes[2] = Temp;
 297
 298                                 return Data.DWord;
 299                         }
 300
 301                         /** Function to reverse the byte ordering of the individual bytes in a n byte number.
 302                          *
 303                          *  \ingroup Group_BitManip
 304                          *
 305                          *  \param[in,out] Data   Pointer to a number containing an even number of bytes to be reversed.
 306                          *  \param[in]     Bytes  Length of the data in bytes.
 307                          */
 308                         static inline void SwapEndian_n(void* Data,
 309                                                         uint8_t Bytes) ATTR_NON_NULL_PTR_ARG(1);
 310                         static inline void SwapEndian_n(void* Data,
 311                                                         uint8_t Bytes)
 312                         {
 313                                 uint8_t* CurrDataPos = (uint8_t*)Data;
 314
 315                                 while (Bytes > 1)
 316                                 {
 317                                         uint8_t Temp = *CurrDataPos;
 318                                         *CurrDataPos = *(CurrDataPos + Bytes - 1);
 319                                         *(CurrDataPos + Bytes - 1) = Temp;
 320
 321                                         CurrDataPos++;
 322                                         Bytes -= 2;
 323                                 }
 324                         }
 325
 326 #endif
 327
 328 /** @} */
 329