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
 144                         #define USE_RAM_DESCRIPTORS
 145                 #endif
 146
 147         /* Public Interface - May be used in end-application: */
 148                 /* Macros: */
 149                         /** Macro for encasing other multi-statement macros. This should be used along with an opening brace
 150                          *  before the start of any multi-statement macro, so that the macros contents as a whole are treated
 151                          *  as a discrete block and not as a list of separate statements which may cause problems when used as
 152                          *  a block (such as inline \c if statements).
 153                          */
 154                         #define MACROS                  do
 155
 156                         /** Macro for encasing other multi-statement macros. This should be used along with a preceding closing
 157                          *  brace at the end of any multi-statement macro, so that the macros contents as a whole are treated
 158                          *  as a discrete block and not as a list of separate statements which may cause problems when used as
 159                          *  a block (such as inline \c if statements).
 160                          */
 161                         #define MACROE                  while (0)
 162
 163                         /** Convenience macro to determine the larger of two values.
 164                          *
 165                          *  \note This macro should only be used with operands that do not have side effects from being evaluated
 166                          *        multiple times.
 167                          *
 168                          *  \param[in] x  First value to compare
 169                          *  \param[in] y  First value to compare
 170                          *
 171                          *  \return The larger of the two input parameters
 172                          */
 173                         #if !defined(MAX) || defined(__DOXYGEN__)
 174                                 #define MAX(x, y)               ((x > y) ? x : y)
 175                         #endif
 176
 177                         /** Convenience macro to determine the smaller of two values.
 178                          *
 179                          *  \note This macro should only be used with operands that do not have side effects from being evaluated
 180                          *        multiple times.
 181                          *
 182                          *  \param[in] x  First value to compare
 183                          *  \param[in] y  First value to compare
 184                          *
 185                          *  \return The smaller of the two input parameters
 186                          */
 187                         #if !defined(MIN) || defined(__DOXYGEN__)
 188                                 #define MIN(x, y)               ((x < y) ? x : y)
 189                         #endif
 190
 191                         #if (ARCH == ARCH_AVR8) || defined(__DOXYGEN__)
 192                                 /** Defines a volatile \c NOP statement which cannot be optimized out by the compiler, and thus can always
 193                                  *  be set as a breakpoint in the resulting code. Useful for debugging purposes, where the optimiser
 194                                  *  removes/reorders code to the point where break points cannot reliably be set.
 195                                  *
 196                                  *  \ingroup Group_Debugging
 197                                  */
 198                                 #define JTAG_DEBUG_POINT()      __asm__ __volatile__ ("NOP" ::)
 199
 200                                 /** Defines an explicit JTAG break point in the resulting binary via the assembly \c BREAK statement. When
 201                                  *  a JTAG is used, this causes the program execution to halt when reached until manually resumed.
 202                                  *
 203                                  *  \ingroup Group_Debugging
 204                                  */
 205                                 #define JTAG_DEBUG_BREAK()      __asm__ __volatile__ ("BREAK" ::)
 206
 207                                 #if !defined(pgm_read_ptr) || defined(__DOXYGEN__)
 208                                         /** Reads a pointer out of PROGMEM space on the AVR8 architecture. This is currently a wrapper for the
 209                                          *  avr-libc \c pgm_read_ptr() macro with a \c void* cast, so that its value can be assigned directly
 210                                          *  to a pointer variable or used in pointer arithmetic without further casting in C. In a future
 211                                          *  avr-libc distribution this will be part of the standard API and will be implemented in a more formal
 212                                          *  manner.
 213                                          *
 214                                          *  \param[in] Addr  Address of the pointer to read.
 215                                          *
 216                                          *  \return Pointer retrieved from PROGMEM space.
 217                                          */
 218                                         #define pgm_read_ptr(Addr)    (void*)pgm_read_word(Addr)
 219                                 #endif
 220
 221                                 /** Macro for testing condition "x" and breaking via \ref JTAG_DEBUG_BREAK() if the condition is false.
 222                                  *
 223                                  *  \param[in] Condition  Condition that will be evaluated,
 224                                  *
 225                                  *  \ingroup Group_Debugging
 226                                 */
 227                                 #define JTAG_DEBUG_ASSERT(Condition)    MACROS{ if (!(Condition)) { JTAG_DEBUG_BREAK(); } }MACROE
 228
 229                                 /** Macro for testing condition "x" and writing debug data to the stdout stream if \c false. The stdout stream
 230                                  *  must be pre-initialized before this macro is run and linked to an output device, such as the microcontroller's
 231                                  *  USART peripheral.
 232                                  *
 233                                  *  The output takes the form "{FILENAME}: Function {FUNCTION NAME}, Line {LINE NUMBER}: Assertion {Condition} failed."
 234                                  *
 235                                  *  \param[in] Condition  Condition that will be evaluated,
 236                                  *
 237                                  *  \ingroup Group_Debugging
 238                                  */
 239                                 #define STDOUT_ASSERT(Condition)        MACROS{ if (!(x)) { printf_P(PSTR("%s: Function \"%s\", Line %d: "   \
 240                                                                                 "Assertion \"%s\" failed.\r\n"),     \
 241                                                                                 __FILE__, __func__, __LINE__, #Condition); } }MACROE
 242                         #endif
 243
 244                         /** Forces GCC to use pointer indirection (via the device's pointer register pairs) when accessing the given
 245                          *  struct pointer. In some cases GCC will emit non-optimal assembly code when accessing a structure through
 246                          *  a pointer, resulting in a larger binary. When this macro is used on a (non \c const) structure pointer before
 247                          *  use, it will force GCC to use pointer indirection on the elements rather than direct store and load
 248                          *  instructions.
 249                          *
 250                          *  \param[in, out] StructPtr  Pointer to a structure which is to be forced into indirect access mode.
 251                          */
 252                         #define GCC_FORCE_POINTER_ACCESS(StructPtr) __asm__ __volatile__("" : "=b" (StructPtr) : "0" (StructPtr))
 253
 254                         /** Swaps the byte ordering of a 16-bit value at compile time. Do not use this macro for swapping byte orderings
 255                          *  of dynamic values computed at runtime, use \ref SwapEndian_16() instead. The result of this macro can be used
 256                          *  inside struct or other variable initializers outside of a function, something that is not possible with the
 257                          *  inline function variant.
 258                          *
 259                          *  \param[in]  x  16-bit value whose byte ordering is to be swapped.
 260                          *
 261                          *  \return Input value with the byte ordering reversed.
 262                          */
 263                         #define SWAPENDIAN_16(x)          ((((x) & 0xFF00) >> 8) | (((x) & 0x00FF) << 8))
 264
 265                         /** Swaps the byte ordering of a 32-bit value at compile time. Do not use this macro for swapping byte orderings
 266                          *  of dynamic values computed at runtime- use \ref SwapEndian_32() instead. The result of this macro can be used
 267                          *  inside struct or other variable initializers outside of a function, something that is not possible with the
 268                          *  inline function variant.
 269                          *
 270                          *  \param[in]  x  32-bit value whose byte ordering is to be swapped.
 271                          *
 272                          *  \return Input value with the byte ordering reversed.
 273                          */
 274                         #define SWAPENDIAN_32(x)          ((((x) & 0xFF000000UL) >> 24UL) | (((x) & 0x00FF0000UL) >> 8UL) | \
 275                                                            (((x) & 0x0000FF00UL) << 8UL)  | (((x) & 0x000000FFUL) << 24UL))
 276
 277                 /* Inline Functions: */
 278                         /** Function to reverse the individual bits in a byte - i.e. bit 7 is moved to bit 0, bit 6 to bit 1,
 279                          *  etc.
 280                          *
 281                          *  \ingroup Group_BitManip
 282                          *
 283                          *  \param[in] Byte  Byte of data whose bits are to be reversed.
 284                          */
 285                         static inline uint8_t BitReverse(uint8_t Byte) ATTR_WARN_UNUSED_RESULT ATTR_CONST;
 286                         static inline uint8_t BitReverse(uint8_t Byte)
 287                         {
 288                                 Byte = (((Byte & 0xF0) >> 4) | ((Byte & 0x0F) << 4));
 289                                 Byte = (((Byte & 0xCC) >> 2) | ((Byte & 0x33) << 2));
 290                                 Byte = (((Byte & 0xAA) >> 1) | ((Byte & 0x55) << 1));
 291
 292                                 return Byte;
 293                         }
 294
 295                         /** Function to reverse the byte ordering of the individual bytes in a 16 bit number.
 296                          *
 297                          *  \ingroup Group_BitManip
 298                          *
 299                          *  \param[in] Word  Word of data whose bytes are to be swapped.
 300                          */
 301                         static inline uint16_t SwapEndian_16(const uint16_t Word) ATTR_WARN_UNUSED_RESULT ATTR_CONST;
 302                         static inline uint16_t SwapEndian_16(const uint16_t Word)
 303                         {
 304                                 uint8_t Temp;
 305
 306                                 union
 307                                 {
 308                                         uint16_t Word;
 309                                         uint8_t  Bytes[2];
 310                                 } Data;
 311
 312                                 Data.Word = Word;
 313
 314                                 Temp = Data.Bytes[0];
 315                                 Data.Bytes[0] = Data.Bytes[1];
 316                                 Data.Bytes[1] = Temp;
 317
 318                                 return Data.Word;
 319                         }
 320
 321                         /** Function to reverse the byte ordering of the individual bytes in a 32 bit number.
 322                          *
 323                          *  \ingroup Group_BitManip
 324                          *
 325                          *  \param[in] DWord  Double word of data whose bytes are to be swapped.
 326                          */
 327                         static inline uint32_t SwapEndian_32(const uint32_t DWord) ATTR_WARN_UNUSED_RESULT ATTR_CONST;
 328                         static inline uint32_t SwapEndian_32(const uint32_t DWord)
 329                         {
 330                                 uint8_t Temp;
 331
 332                                 union
 333                                 {
 334                                         uint32_t DWord;
 335                                         uint8_t  Bytes[4];
 336                                 } Data;
 337
 338                                 Data.DWord = DWord;
 339
 340                                 Temp = Data.Bytes[0];
 341                                 Data.Bytes[0] = Data.Bytes[3];
 342                                 Data.Bytes[3] = Temp;
 343
 344                                 Temp = Data.Bytes[1];
 345                                 Data.Bytes[1] = Data.Bytes[2];
 346                                 Data.Bytes[2] = Temp;
 347
 348                                 return Data.DWord;
 349                         }
 350
 351                         /** Function to reverse the byte ordering of the individual bytes in a n byte number.
 352                          *
 353                          *  \ingroup Group_BitManip
 354                          *
 355                          *  \param[in,out] Data   Pointer to a number containing an even number of bytes to be reversed.
 356                          *  \param[in]     Bytes  Length of the data in bytes.
 357                          */
 358                         static inline void SwapEndian_n(void* Data,
 359                                                         uint8_t Bytes) ATTR_NON_NULL_PTR_ARG(1);
 360                         static inline void SwapEndian_n(void* Data,
 361                                                         uint8_t Bytes)
 362                         {
 363                                 uint8_t* CurrDataPos = (uint8_t*)Data;
 364
 365                                 while (Bytes > 1)
 366                                 {
 367                                         uint8_t Temp = *CurrDataPos;
 368                                         *CurrDataPos = *(CurrDataPos + Bytes - 1);
 369                                         *(CurrDataPos + Bytes - 1) = Temp;
 370
 371                                         CurrDataPos++;
 372                                         Bytes -= 2;
 373                                 }
 374                         }
 375
 376 #endif
 377
 378 /** @} */
 379