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                 #elif (ARCH == ARCH_UC3B)
  91                         #include <avr32/io.h>
  92
  93                         typedef uint32_t uint_reg_t;
  94
  95                         #define EEMEM
  96                         #define PROGMEM                  const
  97                         #define ISR(Name)                void Name (void)
  98                         #define ATOMIC_BLOCK(x)          if (1)
  99                         #define ATOMIC_RESTORESTATE
 100                         #define pgm_read_byte(x)         *x
 101                         #define eeprom_read_byte(x)      *x
 102                         #define eeprom_update_byte(x, y) *x = y
 103                         #define eeprom_write_byte(x, y)  *x = y
 104                         #define memcmp_P(...)            memcmp(__VA_ARGS__)
 105                         #define memcpy_P(...)            memcpy(__VA_ARGS__)
 106
 107                         #warning The UC3B architecture support is currently experimental and incomplete!
 108                 #endif
 109
 110         /* Public Interface - May be used in end-application: */
 111                 /* Macros: */
 112                         /** Macro for encasing other multi-statement macros. This should be used along with an opening brace
 113                          *  before the start of any multi-statement macro, so that the macros contents as a whole are treated
 114                          *  as a discrete block and not as a list of separate statements which may cause problems when used as
 115                          *  a block (such as inline \c if statements).
 116                          */
 117                         #define MACROS                  do
 118
 119                         /** Macro for encasing other multi-statement macros. This should be used along with a preceding closing
 120                          *  brace at the end of any multi-statement macro, so that the macros contents as a whole are treated
 121                          *  as a discrete block and not as a list of separate statements which may cause problems when used as
 122                          *  a block (such as inline \c if statements).
 123                          */
 124                         #define MACROE                  while (0)
 125
 126                         /** Convenience macro to determine the larger of two values.
 127                          *
 128                          *  \note This macro should only be used with operands that do not have side effects from being evaluated
 129                          *        multiple times.
 130                          *
 131                          *  \param[in] x  First value to compare
 132                          *  \param[in] y  First value to compare
 133                          *
 134                          *  \return The larger of the two input parameters
 135                          */
 136                         #if !defined(MAX) || defined(__DOXYGEN__)
 137                                 #define MAX(x, y)               ((x > y) ? x : y)
 138                         #endif
 139
 140                         /** Convenience macro to determine the smaller of two values.
 141                          *
 142                          *  \note This macro should only be used with operands that do not have side effects from being evaluated
 143                          *        multiple times.
 144                          *
 145                          *  \param[in] x  First value to compare
 146                          *  \param[in] y  First value to compare
 147                          *
 148                          *  \return The smaller of the two input parameters
 149                          */
 150                         #if !defined(MIN) || defined(__DOXYGEN__)
 151                                 #define MIN(x, y)               ((x < y) ? x : y)
 152                         #endif
 153
 154                         #if (ARCH == ARCH_AVR8) || defined(__DOXYGEN__)
 155                                 /** Defines a volatile \c NOP statement which cannot be optimized out by the compiler, and thus can always
 156                                  *  be set as a breakpoint in the resulting code. Useful for debugging purposes, where the optimiser
 157                                  *  removes/reorders code to the point where break points cannot reliably be set.
 158                                  *
 159                                  *  \ingroup Group_Debugging
 160                                  */
 161                                 #define JTAG_DEBUG_POINT()      __asm__ __volatile__ ("NOP" ::)
 162
 163                                 /** Defines an explicit JTAG break point in the resulting binary via the assembly \c BREAK statement. When
 164                                  *  a JTAG is used, this causes the program execution to halt when reached until manually resumed.
 165                                  *
 166                                  *  \ingroup Group_Debugging
 167                                  */
 168                                 #define JTAG_DEBUG_BREAK()      __asm__ __volatile__ ("BREAK" ::)
 169
 170                                 #if !defined(pgm_read_ptr) || defined(__DOXYGEN__)
 171                                         /** Reads a pointer out of PROGMEM space on the AVR8 architecture. This is currently a wrapper for the
 172                                          *  avr-libc \c pgm_read_ptr() macro with a \c void* cast, so that its value can be assigned directly
 173                                          *  to a pointer variable or used in pointer arithmetic without further casting in C. In a future
 174                                          *  avr-libc distribution this will be part of the standard API and will be implemented in a more formal
 175                                          *  manner.
 176                                          *
 177                                          *  \param[in] Addr  Address of the pointer to read.
 178                                          *
 179                                          *  \return Pointer retrieved from PROGMEM space.
 180                                          */
 181                                         #define pgm_read_ptr(Addr)    (void*)pgm_read_word(Addr)
 182                                 #endif
 183
 184                                 /** Macro for testing condition "x" and breaking via \ref JTAG_DEBUG_BREAK() if the condition is false.
 185                                  *
 186                                  *  \param[in] Condition  Condition that will be evaluated,
 187                                  *
 188                                  *  \ingroup Group_Debugging
 189                                 */
 190                                 #define JTAG_DEBUG_ASSERT(Condition)    MACROS{ if (!(Condition)) { JTAG_DEBUG_BREAK(); } }MACROE
 191
 192                                 /** Macro for testing condition "x" and writing debug data to the stdout stream if \c false. The stdout stream
 193                                  *  must be pre-initialized before this macro is run and linked to an output device, such as the microcontroller's
 194                                  *  USART peripheral.
 195                                  *
 196                                  *  The output takes the form "{FILENAME}: Function {FUNCTION NAME}, Line {LINE NUMBER}: Assertion {Condition} failed."
 197                                  *
 198                                  *  \param[in] Condition  Condition that will be evaluated,
 199                                  *
 200                                  *  \ingroup Group_Debugging
 201                                  */
 202                                 #define STDOUT_ASSERT(Condition)        MACROS{ if (!(x)) { printf_P(PSTR("%s: Function \"%s\", Line %d: "   \
 203                                                                                 "Assertion \"%s\" failed.\r\n"),     \
 204                                                                                 __FILE__, __func__, __LINE__, #Condition); } }MACROE
 205                         #endif
 206
 207                         /** Forces GCC to use pointer indirection (via the device's pointer register pairs) when accessing the given
 208                          *  struct pointer. In some cases GCC will emit non-optimal assembly code when accessing a structure through
 209                          *  a pointer, resulting in a larger binary. When this macro is used on a (non \c const) structure pointer before
 210                          *  use, it will force GCC to use pointer indirection on the elements rather than direct store and load
 211                          *  instructions.
 212                          *
 213                          *  \param[in, out] StructPtr  Pointer to a structure which is to be forced into indirect access mode.
 214                          */
 215                         #define GCC_FORCE_POINTER_ACCESS(StructPtr) __asm__ __volatile__("" : "=b" (StructPtr) : "0" (StructPtr))
 216
 217                         /** Swaps the byte ordering of a 16-bit value at compile time. Do not use this macro for swapping byte orderings
 218                          *  of dynamic values computed at runtime, use \ref SwapEndian_16() instead. The result of this macro can be used
 219                          *  inside struct or other variable initializers outside of a function, something that is not possible with the
 220                          *  inline function variant.
 221                          *
 222                          *  \param[in]  x  16-bit value whose byte ordering is to be swapped.
 223                          *
 224                          *  \return Input value with the byte ordering reversed.
 225                          */
 226                         #define SWAPENDIAN_16(x)          ((((x) & 0xFF00) >> 8) | (((x) & 0x00FF) << 8))
 227
 228                         /** Swaps the byte ordering of a 32-bit value at compile time. Do not use this macro for swapping byte orderings
 229                          *  of dynamic values computed at runtime- use \ref SwapEndian_32() instead. The result of this macro can be used
 230                          *  inside struct or other variable initializers outside of a function, something that is not possible with the
 231                          *  inline function variant.
 232                          *
 233                          *  \param[in]  x  32-bit value whose byte ordering is to be swapped.
 234                          *
 235                          *  \return Input value with the byte ordering reversed.
 236                          */
 237                         #define SWAPENDIAN_32(x)          ((((x) & 0xFF000000UL) >> 24UL) | (((x) & 0x00FF0000UL) >> 8UL) | \
 238                                                            (((x) & 0x0000FF00UL) << 8UL)  | (((x) & 0x000000FFUL) << 24UL))
 239
 240                 /* Inline Functions: */
 241                         /** Function to reverse the individual bits in a byte - i.e. bit 7 is moved to bit 0, bit 6 to bit 1,
 242                          *  etc.
 243                          *
 244                          *  \ingroup Group_BitManip
 245                          *
 246                          *  \param[in] Byte  Byte of data whose bits are to be reversed.
 247                          */
 248                         static inline uint8_t BitReverse(uint8_t Byte) ATTR_WARN_UNUSED_RESULT ATTR_CONST;
 249                         static inline uint8_t BitReverse(uint8_t Byte)
 250                         {
 251                                 Byte = (((Byte & 0xF0) >> 4) | ((Byte & 0x0F) << 4));
 252                                 Byte = (((Byte & 0xCC) >> 2) | ((Byte & 0x33) << 2));
 253                                 Byte = (((Byte & 0xAA) >> 1) | ((Byte & 0x55) << 1));
 254
 255                                 return Byte;
 256                         }
 257
 258                         /** Function to reverse the byte ordering of the individual bytes in a 16 bit number.
 259                          *
 260                          *  \ingroup Group_BitManip
 261                          *
 262                          *  \param[in] Word  Word of data whose bytes are to be swapped.
 263                          */
 264                         static inline uint16_t SwapEndian_16(const uint16_t Word) ATTR_WARN_UNUSED_RESULT ATTR_CONST;
 265                         static inline uint16_t SwapEndian_16(const uint16_t Word)
 266                         {
 267                                 uint8_t Temp;
 268
 269                                 union
 270                                 {
 271                                         uint16_t Word;
 272                                         uint8_t  Bytes[2];
 273                                 } Data;
 274
 275                                 Data.Word = Word;
 276
 277                                 Temp = Data.Bytes[0];
 278                                 Data.Bytes[0] = Data.Bytes[1];
 279                                 Data.Bytes[1] = Temp;
 280
 281                                 return Data.Word;
 282                         }
 283
 284                         /** Function to reverse the byte ordering of the individual bytes in a 32 bit number.
 285                          *
 286                          *  \ingroup Group_BitManip
 287                          *
 288                          *  \param[in] DWord  Double word of data whose bytes are to be swapped.
 289                          */
 290                         static inline uint32_t SwapEndian_32(const uint32_t DWord) ATTR_WARN_UNUSED_RESULT ATTR_CONST;
 291                         static inline uint32_t SwapEndian_32(const uint32_t DWord)
 292                         {
 293                                 uint8_t Temp;
 294
 295                                 union
 296                                 {
 297                                         uint32_t DWord;
 298                                         uint8_t  Bytes[4];
 299                                 } Data;
 300
 301                                 Data.DWord = DWord;
 302
 303                                 Temp = Data.Bytes[0];
 304                                 Data.Bytes[0] = Data.Bytes[3];
 305                                 Data.Bytes[3] = Temp;
 306
 307                                 Temp = Data.Bytes[1];
 308                                 Data.Bytes[1] = Data.Bytes[2];
 309                                 Data.Bytes[2] = Temp;
 310
 311                                 return Data.DWord;
 312                         }
 313
 314                         /** Function to reverse the byte ordering of the individual bytes in a n byte number.
 315                          *
 316                          *  \ingroup Group_BitManip
 317                          *
 318                          *  \param[in,out] Data   Pointer to a number containing an even number of bytes to be reversed.
 319                          *  \param[in]     Bytes  Length of the data in bytes.
 320                          */
 321                         static inline void SwapEndian_n(void* Data,
 322                                                         uint8_t Bytes) ATTR_NON_NULL_PTR_ARG(1);
 323                         static inline void SwapEndian_n(void* Data,
 324                                                         uint8_t Bytes)
 325                         {
 326                                 uint8_t* CurrDataPos = (uint8_t*)Data;
 327
 328                                 while (Bytes > 1)
 329                                 {
 330                                         uint8_t Temp = *CurrDataPos;
 331                                         *CurrDataPos = *(CurrDataPos + Bytes - 1);
 332                                         *(CurrDataPos + Bytes - 1) = Temp;
 333
 334                                         CurrDataPos++;
 335                                         Bytes -= 2;
 336                                 }
 337                         }
 338
 339 #endif
 340
 341 /** @} */
 342