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                         // TODO
  96                         #define EEMEM
  97                         #define PROGMEM                  const
  98                         #define ISR(Name)                void Name (void)
  99                         #define ATOMIC_BLOCK(x)          if (1)
 100                         #define ATOMIC_RESTORESTATE
 101                         #define pgm_read_byte(x)         *x
 102                         #define eeprom_read_byte(x)      *x
 103                         #define eeprom_update_byte(x, y) *x = y
 104                         #define eeprom_write_byte(x, y)  *x = y
 105                         #define _delay_ms(x)
 106                         #define memcmp_P(...)            memcmp(__VA_ARGS__)
 107                         #define memcpy_P(...)            memcpy(__VA_ARGS__)
 108
 109                         #warning The UC3B architecture support is currently experimental and incomplete!
 110                 #endif
 111
 112         /* Public Interface - May be used in end-application: */
 113                 /* Macros: */
 114                         /** Macro for encasing other multi-statement macros. This should be used along with an opening brace
 115                          *  before the start of any multi-statement macro, so that the macros contents as a whole are treated
 116                          *  as a discrete block and not as a list of separate statements which may cause problems when used as
 117                          *  a block (such as inline \c if statements).
 118                          */
 119                         #define MACROS                  do
 120
 121                         /** Macro for encasing other multi-statement macros. This should be used along with a preceding closing
 122                          *  brace at the end of any multi-statement macro, so that the macros contents as a whole are treated
 123                          *  as a discrete block and not as a list of separate statements which may cause problems when used as
 124                          *  a block (such as inline \c if statements).
 125                          */
 126                         #define MACROE                  while (0)
 127
 128                         /** Convenience macro to determine the larger of two values.
 129                          *
 130                          *  \note This macro should only be used with operands that do not have side effects from being evaluated
 131                          *        multiple times.
 132                          *
 133                          *  \param[in] x  First value to compare
 134                          *  \param[in] y  First value to compare
 135                          *
 136                          *  \return The larger of the two input parameters
 137                          */
 138                         #if !defined(MAX) || defined(__DOXYGEN__)
 139                                 #define MAX(x, y)               ((x > y) ? x : y)
 140                         #endif
 141
 142                         /** Convenience macro to determine the smaller of two values.
 143                          *
 144                          *  \note This macro should only be used with operands that do not have side effects from being evaluated
 145                          *        multiple times.
 146                          *
 147                          *  \param[in] x  First value to compare
 148                          *  \param[in] y  First value to compare
 149                          *
 150                          *  \return The smaller of the two input parameters
 151                          */
 152                         #if !defined(MIN) || defined(__DOXYGEN__)
 153                                 #define MIN(x, y)               ((x < y) ? x : y)
 154                         #endif
 155
 156                         #if (ARCH == ARCH_AVR8) || defined(__DOXYGEN__)
 157                                 /** Defines a volatile \c NOP statement which cannot be optimized out by the compiler, and thus can always
 158                                  *  be set as a breakpoint in the resulting code. Useful for debugging purposes, where the optimiser
 159                                  *  removes/reorders code to the point where break points cannot reliably be set.
 160                                  *
 161                                  *  \ingroup Group_Debugging
 162                                  */
 163                                 #define JTAG_DEBUG_POINT()      __asm__ __volatile__ ("NOP" ::)
 164
 165                                 /** Defines an explicit JTAG break point in the resulting binary via the assembly \c BREAK statement. When
 166                                  *  a JTAG is used, this causes the program execution to halt when reached until manually resumed.
 167                                  *
 168                                  *  \ingroup Group_Debugging
 169                                  */
 170                                 #define JTAG_DEBUG_BREAK()      __asm__ __volatile__ ("BREAK" ::)
 171
 172                                 #if !defined(pgm_read_ptr) || defined(__DOXYGEN__)
 173                                         /** Reads a pointer out of PROGMEM space on the AVR8 architecture. This is currently a wrapper for the
 174                                          *  avr-libc \c pgm_read_ptr() macro with a \c void* cast, so that its value can be assigned directly
 175                                          *  to a pointer variable or used in pointer arithmetic without further casting in C. In a future
 176                                          *  avr-libc distribution this will be part of the standard API and will be implemented in a more formal
 177                                          *  manner.
 178                                          *
 179                                          *  \param[in] Addr  Address of the pointer to read.
 180                                          *
 181                                          *  \return Pointer retrieved from PROGMEM space.
 182                                          */
 183                                         #define pgm_read_ptr(Addr)    (void*)pgm_read_word(Addr)
 184                                 #endif
 185
 186                                 /** Macro for testing condition "x" and breaking via \ref JTAG_DEBUG_BREAK() if the condition is false.
 187                                  *
 188                                  *  \param[in] Condition  Condition that will be evaluated,
 189                                  *
 190                                  *  \ingroup Group_Debugging
 191                                 */
 192                                 #define JTAG_DEBUG_ASSERT(Condition)    MACROS{ if (!(Condition)) { JTAG_DEBUG_BREAK(); } }MACROE
 193
 194                                 /** Macro for testing condition "x" and writing debug data to the stdout stream if \c false. The stdout stream
 195                                  *  must be pre-initialized before this macro is run and linked to an output device, such as the microcontroller's
 196                                  *  USART peripheral.
 197                                  *
 198                                  *  The output takes the form "{FILENAME}: Function {FUNCTION NAME}, Line {LINE NUMBER}: Assertion {Condition} failed."
 199                                  *
 200                                  *  \param[in] Condition  Condition that will be evaluated,
 201                                  *
 202                                  *  \ingroup Group_Debugging
 203                                  */
 204                                 #define STDOUT_ASSERT(Condition)        MACROS{ if (!(x)) { printf_P(PSTR("%s: Function \"%s\", Line %d: "   \
 205                                                                                 "Assertion \"%s\" failed.\r\n"),     \
 206                                                                                 __FILE__, __func__, __LINE__, #Condition); } }MACROE
 207                         #endif
 208
 209                         /** Forces GCC to use pointer indirection (via the device's pointer register pairs) when accessing the given
 210                          *  struct pointer. In some cases GCC will emit non-optimal assembly code when accessing a structure through
 211                          *  a pointer, resulting in a larger binary. When this macro is used on a (non \c const) structure pointer before
 212                          *  use, it will force GCC to use pointer indirection on the elements rather than direct store and load
 213                          *  instructions.
 214                          *
 215                          *  \param[in, out] StructPtr  Pointer to a structure which is to be forced into indirect access mode.
 216                          */
 217                         #define GCC_FORCE_POINTER_ACCESS(StructPtr) __asm__ __volatile__("" : "=b" (StructPtr) : "0" (StructPtr))
 218
 219                         /** Swaps the byte ordering of a 16-bit value at compile time. Do not use this macro for swapping byte orderings
 220                          *  of dynamic values computed at runtime, use \ref SwapEndian_16() instead. The result of this macro can be used
 221                          *  inside struct or other variable initializers outside of a function, something that is not possible with the
 222                          *  inline function variant.
 223                          *
 224                          *  \param[in]  x  16-bit value whose byte ordering is to be swapped.
 225                          *
 226                          *  \return Input value with the byte ordering reversed.
 227                          */
 228                         #define SWAPENDIAN_16(x)          ((((x) & 0xFF00) >> 8) | (((x) & 0x00FF) << 8))
 229
 230                         /** Swaps the byte ordering of a 32-bit value at compile time. Do not use this macro for swapping byte orderings
 231                          *  of dynamic values computed at runtime- use \ref SwapEndian_32() instead. The result of this macro can be used
 232                          *  inside struct or other variable initializers outside of a function, something that is not possible with the
 233                          *  inline function variant.
 234                          *
 235                          *  \param[in]  x  32-bit value whose byte ordering is to be swapped.
 236                          *
 237                          *  \return Input value with the byte ordering reversed.
 238                          */
 239                         #define SWAPENDIAN_32(x)          ((((x) & 0xFF000000UL) >> 24UL) | (((x) & 0x00FF0000UL) >> 8UL) | \
 240                                                            (((x) & 0x0000FF00UL) << 8UL)  | (((x) & 0x000000FFUL) << 24UL))
 241
 242                 /* Inline Functions: */
 243                         /** Function to reverse the individual bits in a byte - i.e. bit 7 is moved to bit 0, bit 6 to bit 1,
 244                          *  etc.
 245                          *
 246                          *  \ingroup Group_BitManip
 247                          *
 248                          *  \param[in] Byte  Byte of data whose bits are to be reversed.
 249                          */
 250                         static inline uint8_t BitReverse(uint8_t Byte) ATTR_WARN_UNUSED_RESULT ATTR_CONST;
 251                         static inline uint8_t BitReverse(uint8_t Byte)
 252                         {
 253                                 Byte = (((Byte & 0xF0) >> 4) | ((Byte & 0x0F) << 4));
 254                                 Byte = (((Byte & 0xCC) >> 2) | ((Byte & 0x33) << 2));
 255                                 Byte = (((Byte & 0xAA) >> 1) | ((Byte & 0x55) << 1));
 256
 257                                 return Byte;
 258                         }
 259
 260                         /** Function to reverse the byte ordering of the individual bytes in a 16 bit number.
 261                          *
 262                          *  \ingroup Group_BitManip
 263                          *
 264                          *  \param[in] Word  Word of data whose bytes are to be swapped.
 265                          */
 266                         static inline uint16_t SwapEndian_16(const uint16_t Word) ATTR_WARN_UNUSED_RESULT ATTR_CONST;
 267                         static inline uint16_t SwapEndian_16(const uint16_t Word)
 268                         {
 269                                 uint8_t Temp;
 270
 271                                 union
 272                                 {
 273                                         uint16_t Word;
 274                                         uint8_t  Bytes[2];
 275                                 } Data;
 276
 277                                 Data.Word = Word;
 278
 279                                 Temp = Data.Bytes[0];
 280                                 Data.Bytes[0] = Data.Bytes[1];
 281                                 Data.Bytes[1] = Temp;
 282
 283                                 return Data.Word;
 284                         }
 285
 286                         /** Function to reverse the byte ordering of the individual bytes in a 32 bit number.
 287                          *
 288                          *  \ingroup Group_BitManip
 289                          *
 290                          *  \param[in] DWord  Double word of data whose bytes are to be swapped.
 291                          */
 292                         static inline uint32_t SwapEndian_32(const uint32_t DWord) ATTR_WARN_UNUSED_RESULT ATTR_CONST;
 293                         static inline uint32_t SwapEndian_32(const uint32_t DWord)
 294                         {
 295                                 uint8_t Temp;
 296
 297                                 union
 298                                 {
 299                                         uint32_t DWord;
 300                                         uint8_t  Bytes[4];
 301                                 } Data;
 302
 303                                 Data.DWord = DWord;
 304
 305                                 Temp = Data.Bytes[0];
 306                                 Data.Bytes[0] = Data.Bytes[3];
 307                                 Data.Bytes[3] = Temp;
 308
 309                                 Temp = Data.Bytes[1];
 310                                 Data.Bytes[1] = Data.Bytes[2];
 311                                 Data.Bytes[2] = Temp;
 312
 313                                 return Data.DWord;
 314                         }
 315
 316                         /** Function to reverse the byte ordering of the individual bytes in a n byte number.
 317                          *
 318                          *  \ingroup Group_BitManip
 319                          *
 320                          *  \param[in,out] Data   Pointer to a number containing an even number of bytes to be reversed.
 321                          *  \param[in]     Bytes  Length of the data in bytes.
 322                          */
 323                         static inline void SwapEndian_n(void* Data,
 324                                                         uint8_t Bytes) ATTR_NON_NULL_PTR_ARG(1);
 325                         static inline void SwapEndian_n(void* Data,
 326                                                         uint8_t Bytes)
 327                         {
 328                                 uint8_t* CurrDataPos = (uint8_t*)Data;
 329
 330                                 while (Bytes > 1)
 331                                 {
 332                                         uint8_t Temp = *CurrDataPos;
 333                                         *CurrDataPos = *(CurrDataPos + Bytes - 1);
 334                                         *(CurrDataPos + Bytes - 1) = Temp;
 335
 336                                         CurrDataPos++;
 337                                         Bytes -= 2;
 338                                 }
 339                         }
 340
 341 #endif
 342
 343 /** @} */
 344