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 defined(__DOXYGEN__)
  78                         /** Type define for an unsigned integer the same width as the selected architecture's machine register. */
  79                         typedef MACHINE_REG_t uint_reg_t;
  80                 #elif (ARCH == ARCH_AVR8)
  81                         #include <avr/io.h>
  82                         #include <avr/interrupt.h>
  83                         #include <avr/pgmspace.h>
  84                         #include <avr/eeprom.h>
  85                         #include <avr/boot.h>
  86                         #include <util/atomic.h>
  87                         #include <util/delay.h>
  88
  89                         typedef uint8_t uint_reg_t;
  90
  91                         #define le16_to_cpu(x)           x
  92                         #define le32_to_cpu(x)           x
  93                         #define be16_to_cpu(x)           SwapEndian_16(x)
  94                         #define be32_to_cpu(x)           SwapEndian_32(x)
  95                         #define cpu_to_le16(x)           x
  96                         #define cpu_to_le32(x)           x
  97                         #define cpu_to_be16(x)           SwapEndian_16(x)
  98                         #define cpu_to_be32(x)           SwapEndian_32(x)
  99                         #define LE16_TO_CPU(x)           x
 100                         #define LE32_TO_CPU(x)           x
 101                         #define BE16_TO_CPU(x)           SWAPENDIAN_16(x)
 102                         #define BE32_TO_CPU(x)           SWAPENDIAN_32(x)
 103                         #define CPU_TO_LE16(x)           x
 104                         #define CPU_TO_LE32(x)           x
 105                         #define CPU_TO_BE16(x)           SWAPENDIAN_16(x)
 106                         #define CPU_TO_BE32(x)           SWAPENDIAN_32(x)
 107
 108                 #elif (ARCH == ARCH_UC3B)
 109                         #include <avr32/io.h>
 110
 111                         typedef uint32_t uint_reg_t;
 112
 113                         // TODO
 114                         #define le16_to_cpu(x)           SwapEndian_16(x)
 115                         #define le32_to_cpu(x)           SwapEndian_32(x)
 116                         #define be16_to_cpu(x)           x
 117                         #define be32_to_cpu(x)           x
 118                         #define cpu_to_le16(x)           SwapEndian_16(x)
 119                         #define cpu_to_le32(x)           SwapEndian_32(x)
 120                         #define cpu_to_be16(x)           x
 121                         #define cpu_to_be32(x)           x
 122                         #define LE16_TO_CPU(x)           SWAPENDIAN_16(x)
 123                         #define LE32_TO_CPU(x)           SWAPENDIAN_32(x)
 124                         #define BE16_TO_CPU(x)           x
 125                         #define BE32_TO_CPU(x)           x
 126                         #define CPU_TO_LE16(x)           SWAPENDIAN_16(x)
 127                         #define CPU_TO_LE32(x)           SWAPENDIAN_32(x)
 128                         #define CPU_TO_BE16(x)           x
 129                         #define CPU_TO_BE32(x)           x
 130
 131                         #define ISR(Name)                void Name (void) __attribute__((__interrupt__)); void Name (void)
 132                         #define EEMEM
 133                         #define PROGMEM                  const
 134                         #define ATOMIC_BLOCK(x)          if (1)
 135                         #define ATOMIC_RESTORESTATE
 136                         #define pgm_read_byte(x)         *x
 137                         #define eeprom_read_byte(x)      *x
 138                         #define eeprom_update_byte(x, y) *x = y
 139                         #define eeprom_write_byte(x, y)  *x = y
 140                         #define _delay_ms(x)
 141                         #define memcmp_P(...)            memcmp(__VA_ARGS__)
 142                         #define memcpy_P(...)            memcpy(__VA_ARGS__)
 143                 #endif
 144
 145         /* Public Interface - May be used in end-application: */
 146                 /* Macros: */
 147                         /** Macro for encasing other multi-statement macros. This should be used along with an opening brace
 148                          *  before the start of any multi-statement macro, so that the macros contents as a whole are treated
 149                          *  as a discrete block and not as a list of separate statements which may cause problems when used as
 150                          *  a block (such as inline \c if statements).
 151                          */
 152                         #define MACROS                  do
 153
 154                         /** Macro for encasing other multi-statement macros. This should be used along with a preceding closing
 155                          *  brace at the end of any multi-statement macro, so that the macros contents as a whole are treated
 156                          *  as a discrete block and not as a list of separate statements which may cause problems when used as
 157                          *  a block (such as inline \c if statements).
 158                          */
 159                         #define MACROE                  while (0)
 160
 161                         /** Convenience macro to determine the larger of two values.
 162                          *
 163                          *  \note This macro should only be used with operands that do not have side effects from being evaluated
 164                          *        multiple times.
 165                          *
 166                          *  \param[in] x  First value to compare
 167                          *  \param[in] y  First value to compare
 168                          *
 169                          *  \return The larger of the two input parameters
 170                          */
 171                         #if !defined(MAX) || defined(__DOXYGEN__)
 172                                 #define MAX(x, y)               ((x > y) ? x : y)
 173                         #endif
 174
 175                         /** Convenience macro to determine the smaller of two values.
 176                          *
 177                          *  \note This macro should only be used with operands that do not have side effects from being evaluated
 178                          *        multiple times.
 179                          *
 180                          *  \param[in] x  First value to compare
 181                          *  \param[in] y  First value to compare
 182                          *
 183                          *  \return The smaller of the two input parameters
 184                          */
 185                         #if !defined(MIN) || defined(__DOXYGEN__)
 186                                 #define MIN(x, y)               ((x < y) ? x : y)
 187                         #endif
 188
 189                         #if (ARCH == ARCH_AVR8) || defined(__DOXYGEN__)
 190                                 /** Defines a volatile \c NOP statement which cannot be optimized out by the compiler, and thus can always
 191                                  *  be set as a breakpoint in the resulting code. Useful for debugging purposes, where the optimiser
 192                                  *  removes/reorders code to the point where break points cannot reliably be set.
 193                                  *
 194                                  *  \ingroup Group_Debugging
 195                                  */
 196                                 #define JTAG_DEBUG_POINT()      __asm__ __volatile__ ("NOP" ::)
 197
 198                                 /** Defines an explicit JTAG break point in the resulting binary via the assembly \c BREAK statement. When
 199                                  *  a JTAG is used, this causes the program execution to halt when reached until manually resumed.
 200                                  *
 201                                  *  \ingroup Group_Debugging
 202                                  */
 203                                 #define JTAG_DEBUG_BREAK()      __asm__ __volatile__ ("BREAK" ::)
 204
 205                                 #if !defined(pgm_read_ptr) || defined(__DOXYGEN__)
 206                                         /** Reads a pointer out of PROGMEM space on the AVR8 architecture. This is currently a wrapper for the
 207                                          *  avr-libc \c pgm_read_ptr() macro with a \c void* cast, so that its value can be assigned directly
 208                                          *  to a pointer variable or used in pointer arithmetic without further casting in C. In a future
 209                                          *  avr-libc distribution this will be part of the standard API and will be implemented in a more formal
 210                                          *  manner.
 211                                          *
 212                                          *  \param[in] Addr  Address of the pointer to read.
 213                                          *
 214                                          *  \return Pointer retrieved from PROGMEM space.
 215                                          */
 216                                         #define pgm_read_ptr(Addr)    (void*)pgm_read_word(Addr)
 217                                 #endif
 218
 219                                 /** Macro for testing condition "x" and breaking via \ref JTAG_DEBUG_BREAK() if the condition is false.
 220                                  *
 221                                  *  \param[in] Condition  Condition that will be evaluated,
 222                                  *
 223                                  *  \ingroup Group_Debugging
 224                                 */
 225                                 #define JTAG_DEBUG_ASSERT(Condition)    MACROS{ if (!(Condition)) { JTAG_DEBUG_BREAK(); } }MACROE
 226
 227                                 /** Macro for testing condition "x" and writing debug data to the stdout stream if \c false. The stdout stream
 228                                  *  must be pre-initialized before this macro is run and linked to an output device, such as the microcontroller's
 229                                  *  USART peripheral.
 230                                  *
 231                                  *  The output takes the form "{FILENAME}: Function {FUNCTION NAME}, Line {LINE NUMBER}: Assertion {Condition} failed."
 232                                  *
 233                                  *  \param[in] Condition  Condition that will be evaluated,
 234                                  *
 235                                  *  \ingroup Group_Debugging
 236                                  */
 237                                 #define STDOUT_ASSERT(Condition)        MACROS{ if (!(x)) { printf_P(PSTR("%s: Function \"%s\", Line %d: "   \
 238                                                                                 "Assertion \"%s\" failed.\r\n"),     \
 239                                                                                 __FILE__, __func__, __LINE__, #Condition); } }MACROE
 240                         #endif
 241
 242                         /** Forces GCC to use pointer indirection (via the device's pointer register pairs) when accessing the given
 243                          *  struct pointer. In some cases GCC will emit non-optimal assembly code when accessing a structure through
 244                          *  a pointer, resulting in a larger binary. When this macro is used on a (non \c const) structure pointer before
 245                          *  use, it will force GCC to use pointer indirection on the elements rather than direct store and load
 246                          *  instructions.
 247                          *
 248                          *  \param[in, out] StructPtr  Pointer to a structure which is to be forced into indirect access mode.
 249                          */
 250                         #define GCC_FORCE_POINTER_ACCESS(StructPtr) __asm__ __volatile__("" : "=b" (StructPtr) : "0" (StructPtr))
 251
 252                         /** Swaps the byte ordering of a 16-bit value at compile time. Do not use this macro for swapping byte orderings
 253                          *  of dynamic values computed at runtime, use \ref SwapEndian_16() instead. The result of this macro can be used
 254                          *  inside struct or other variable initializers outside of a function, something that is not possible with the
 255                          *  inline function variant.
 256                          *
 257                          *  \param[in]  x  16-bit value whose byte ordering is to be swapped.
 258                          *
 259                          *  \return Input value with the byte ordering reversed.
 260                          */
 261                         #define SWAPENDIAN_16(x)          ((((x) & 0xFF00) >> 8) | (((x) & 0x00FF) << 8))
 262
 263                         /** Swaps the byte ordering of a 32-bit value at compile time. Do not use this macro for swapping byte orderings
 264                          *  of dynamic values computed at runtime- use \ref SwapEndian_32() instead. The result of this macro can be used
 265                          *  inside struct or other variable initializers outside of a function, something that is not possible with the
 266                          *  inline function variant.
 267                          *
 268                          *  \param[in]  x  32-bit value whose byte ordering is to be swapped.
 269                          *
 270                          *  \return Input value with the byte ordering reversed.
 271                          */
 272                         #define SWAPENDIAN_32(x)          ((((x) & 0xFF000000UL) >> 24UL) | (((x) & 0x00FF0000UL) >> 8UL) | \
 273                                                            (((x) & 0x0000FF00UL) << 8UL)  | (((x) & 0x000000FFUL) << 24UL))
 274
 275                 /* Inline Functions: */
 276                         /** Function to reverse the individual bits in a byte - i.e. bit 7 is moved to bit 0, bit 6 to bit 1,
 277                          *  etc.
 278                          *
 279                          *  \ingroup Group_BitManip
 280                          *
 281                          *  \param[in] Byte  Byte of data whose bits are to be reversed.
 282                          */
 283                         static inline uint8_t BitReverse(uint8_t Byte) ATTR_WARN_UNUSED_RESULT ATTR_CONST;
 284                         static inline uint8_t BitReverse(uint8_t Byte)
 285                         {
 286                                 Byte = (((Byte & 0xF0) >> 4) | ((Byte & 0x0F) << 4));
 287                                 Byte = (((Byte & 0xCC) >> 2) | ((Byte & 0x33) << 2));
 288                                 Byte = (((Byte & 0xAA) >> 1) | ((Byte & 0x55) << 1));
 289
 290                                 return Byte;
 291                         }
 292
 293                         /** Function to reverse the byte ordering of the individual bytes in a 16 bit number.
 294                          *
 295                          *  \ingroup Group_BitManip
 296                          *
 297                          *  \param[in] Word  Word of data whose bytes are to be swapped.
 298                          */
 299                         static inline uint16_t SwapEndian_16(const uint16_t Word) ATTR_WARN_UNUSED_RESULT ATTR_CONST;
 300                         static inline uint16_t SwapEndian_16(const uint16_t Word)
 301                         {
 302                                 uint8_t Temp;
 303
 304                                 union
 305                                 {
 306                                         uint16_t Word;
 307                                         uint8_t  Bytes[2];
 308                                 } Data;
 309
 310                                 Data.Word = Word;
 311
 312                                 Temp = Data.Bytes[0];
 313                                 Data.Bytes[0] = Data.Bytes[1];
 314                                 Data.Bytes[1] = Temp;
 315
 316                                 return Data.Word;
 317                         }
 318
 319                         /** Function to reverse the byte ordering of the individual bytes in a 32 bit number.
 320                          *
 321                          *  \ingroup Group_BitManip
 322                          *
 323                          *  \param[in] DWord  Double word of data whose bytes are to be swapped.
 324                          */
 325                         static inline uint32_t SwapEndian_32(const uint32_t DWord) ATTR_WARN_UNUSED_RESULT ATTR_CONST;
 326                         static inline uint32_t SwapEndian_32(const uint32_t DWord)
 327                         {
 328                                 uint8_t Temp;
 329
 330                                 union
 331                                 {
 332                                         uint32_t DWord;
 333                                         uint8_t  Bytes[4];
 334                                 } Data;
 335
 336                                 Data.DWord = DWord;
 337
 338                                 Temp = Data.Bytes[0];
 339                                 Data.Bytes[0] = Data.Bytes[3];
 340                                 Data.Bytes[3] = Temp;
 341
 342                                 Temp = Data.Bytes[1];
 343                                 Data.Bytes[1] = Data.Bytes[2];
 344                                 Data.Bytes[2] = Temp;
 345
 346                                 return Data.DWord;
 347                         }
 348
 349                         /** Function to reverse the byte ordering of the individual bytes in a n byte number.
 350                          *
 351                          *  \ingroup Group_BitManip
 352                          *
 353                          *  \param[in,out] Data   Pointer to a number containing an even number of bytes to be reversed.
 354                          *  \param[in]     Bytes  Length of the data in bytes.
 355                          */
 356                         static inline void SwapEndian_n(void* Data,
 357                                                         uint8_t Bytes) ATTR_NON_NULL_PTR_ARG(1);
 358                         static inline void SwapEndian_n(void* Data,
 359                                                         uint8_t Bytes)
 360                         {
 361                                 uint8_t* CurrDataPos = (uint8_t*)Data;
 362
 363                                 while (Bytes > 1)
 364                                 {
 365                                         uint8_t Temp = *CurrDataPos;
 366                                         *CurrDataPos = *(CurrDataPos + Bytes - 1);
 367                                         *(CurrDataPos + Bytes - 1) = Temp;
 368
 369                                         CurrDataPos++;
 370                                         Bytes -= 2;
 371                                 }
 372                         }
 373
 374 #endif
 375
 376 /** @} */
 377