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) __attribute__((__interrupt__)); 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                         #define cpu_irq_enable()         do { asm volatile("" ::: "memory"); __builtin_csrf(AVR32_SR_GM_OFFSET); } while (0)
 109                         #define cpu_irq_disable()        do { __builtin_ssrf(AVR32_SR_GM_OFFSET); asm volatile("" ::: "memory"); } while (0)
 110
 111                         #warning The UC3B architecture support is currently experimental and incomplete!
 112                 #endif
 113
 114         /* Public Interface - May be used in end-application: */
 115                 /* Macros: */
 116                         /** Macro for encasing other multi-statement macros. This should be used along with an opening brace
 117                          *  before the start of any multi-statement macro, so that the macros contents as a whole are treated
 118                          *  as a discrete block and not as a list of separate statements which may cause problems when used as
 119                          *  a block (such as inline \c if statements).
 120                          */
 121                         #define MACROS                  do
 122
 123                         /** Macro for encasing other multi-statement macros. This should be used along with a preceding closing
 124                          *  brace at the end of any multi-statement macro, so that the macros contents as a whole are treated
 125                          *  as a discrete block and not as a list of separate statements which may cause problems when used as
 126                          *  a block (such as inline \c if statements).
 127                          */
 128                         #define MACROE                  while (0)
 129
 130                         /** Convenience macro to determine the larger of two values.
 131                          *
 132                          *  \note This macro should only be used with operands that do not have side effects from being evaluated
 133                          *        multiple times.
 134                          *
 135                          *  \param[in] x  First value to compare
 136                          *  \param[in] y  First value to compare
 137                          *
 138                          *  \return The larger of the two input parameters
 139                          */
 140                         #if !defined(MAX) || defined(__DOXYGEN__)
 141                                 #define MAX(x, y)               ((x > y) ? x : y)
 142                         #endif
 143
 144                         /** Convenience macro to determine the smaller of two values.
 145                          *
 146                          *  \note This macro should only be used with operands that do not have side effects from being evaluated
 147                          *        multiple times.
 148                          *
 149                          *  \param[in] x  First value to compare
 150                          *  \param[in] y  First value to compare
 151                          *
 152                          *  \return The smaller of the two input parameters
 153                          */
 154                         #if !defined(MIN) || defined(__DOXYGEN__)
 155                                 #define MIN(x, y)               ((x < y) ? x : y)
 156                         #endif
 157
 158                         #if (ARCH == ARCH_AVR8) || defined(__DOXYGEN__)
 159                                 /** Defines a volatile \c NOP statement which cannot be optimized out by the compiler, and thus can always
 160                                  *  be set as a breakpoint in the resulting code. Useful for debugging purposes, where the optimiser
 161                                  *  removes/reorders code to the point where break points cannot reliably be set.
 162                                  *
 163                                  *  \ingroup Group_Debugging
 164                                  */
 165                                 #define JTAG_DEBUG_POINT()      __asm__ __volatile__ ("NOP" ::)
 166
 167                                 /** Defines an explicit JTAG break point in the resulting binary via the assembly \c BREAK statement. When
 168                                  *  a JTAG is used, this causes the program execution to halt when reached until manually resumed.
 169                                  *
 170                                  *  \ingroup Group_Debugging
 171                                  */
 172                                 #define JTAG_DEBUG_BREAK()      __asm__ __volatile__ ("BREAK" ::)
 173
 174                                 #if !defined(pgm_read_ptr) || defined(__DOXYGEN__)
 175                                         /** Reads a pointer out of PROGMEM space on the AVR8 architecture. This is currently a wrapper for the
 176                                          *  avr-libc \c pgm_read_ptr() macro with a \c void* cast, so that its value can be assigned directly
 177                                          *  to a pointer variable or used in pointer arithmetic without further casting in C. In a future
 178                                          *  avr-libc distribution this will be part of the standard API and will be implemented in a more formal
 179                                          *  manner.
 180                                          *
 181                                          *  \param[in] Addr  Address of the pointer to read.
 182                                          *
 183                                          *  \return Pointer retrieved from PROGMEM space.
 184                                          */
 185                                         #define pgm_read_ptr(Addr)    (void*)pgm_read_word(Addr)
 186                                 #endif
 187
 188                                 /** Macro for testing condition "x" and breaking via \ref JTAG_DEBUG_BREAK() if the condition is false.
 189                                  *
 190                                  *  \param[in] Condition  Condition that will be evaluated,
 191                                  *
 192                                  *  \ingroup Group_Debugging
 193                                 */
 194                                 #define JTAG_DEBUG_ASSERT(Condition)    MACROS{ if (!(Condition)) { JTAG_DEBUG_BREAK(); } }MACROE
 195
 196                                 /** Macro for testing condition "x" and writing debug data to the stdout stream if \c false. The stdout stream
 197                                  *  must be pre-initialized before this macro is run and linked to an output device, such as the microcontroller's
 198                                  *  USART peripheral.
 199                                  *
 200                                  *  The output takes the form "{FILENAME}: Function {FUNCTION NAME}, Line {LINE NUMBER}: Assertion {Condition} failed."
 201                                  *
 202                                  *  \param[in] Condition  Condition that will be evaluated,
 203                                  *
 204                                  *  \ingroup Group_Debugging
 205                                  */
 206                                 #define STDOUT_ASSERT(Condition)        MACROS{ if (!(x)) { printf_P(PSTR("%s: Function \"%s\", Line %d: "   \
 207                                                                                 "Assertion \"%s\" failed.\r\n"),     \
 208                                                                                 __FILE__, __func__, __LINE__, #Condition); } }MACROE
 209                         #endif
 210
 211                         /** Forces GCC to use pointer indirection (via the device's pointer register pairs) when accessing the given
 212                          *  struct pointer. In some cases GCC will emit non-optimal assembly code when accessing a structure through
 213                          *  a pointer, resulting in a larger binary. When this macro is used on a (non \c const) structure pointer before
 214                          *  use, it will force GCC to use pointer indirection on the elements rather than direct store and load
 215                          *  instructions.
 216                          *
 217                          *  \param[in, out] StructPtr  Pointer to a structure which is to be forced into indirect access mode.
 218                          */
 219                         #define GCC_FORCE_POINTER_ACCESS(StructPtr) __asm__ __volatile__("" : "=b" (StructPtr) : "0" (StructPtr))
 220
 221                         /** Swaps the byte ordering of a 16-bit value at compile time. Do not use this macro for swapping byte orderings
 222                          *  of dynamic values computed at runtime, use \ref SwapEndian_16() instead. The result of this macro can be used
 223                          *  inside struct or other variable initializers outside of a function, something that is not possible with the
 224                          *  inline function variant.
 225                          *
 226                          *  \param[in]  x  16-bit value whose byte ordering is to be swapped.
 227                          *
 228                          *  \return Input value with the byte ordering reversed.
 229                          */
 230                         #define SWAPENDIAN_16(x)          ((((x) & 0xFF00) >> 8) | (((x) & 0x00FF) << 8))
 231
 232                         /** Swaps the byte ordering of a 32-bit value at compile time. Do not use this macro for swapping byte orderings
 233                          *  of dynamic values computed at runtime- use \ref SwapEndian_32() instead. The result of this macro can be used
 234                          *  inside struct or other variable initializers outside of a function, something that is not possible with the
 235                          *  inline function variant.
 236                          *
 237                          *  \param[in]  x  32-bit value whose byte ordering is to be swapped.
 238                          *
 239                          *  \return Input value with the byte ordering reversed.
 240                          */
 241                         #define SWAPENDIAN_32(x)          ((((x) & 0xFF000000UL) >> 24UL) | (((x) & 0x00FF0000UL) >> 8UL) | \
 242                                                            (((x) & 0x0000FF00UL) << 8UL)  | (((x) & 0x000000FFUL) << 24UL))
 243
 244                 /* Inline Functions: */
 245                         /** Function to reverse the individual bits in a byte - i.e. bit 7 is moved to bit 0, bit 6 to bit 1,
 246                          *  etc.
 247                          *
 248                          *  \ingroup Group_BitManip
 249                          *
 250                          *  \param[in] Byte  Byte of data whose bits are to be reversed.
 251                          */
 252                         static inline uint8_t BitReverse(uint8_t Byte) ATTR_WARN_UNUSED_RESULT ATTR_CONST;
 253                         static inline uint8_t BitReverse(uint8_t Byte)
 254                         {
 255                                 Byte = (((Byte & 0xF0) >> 4) | ((Byte & 0x0F) << 4));
 256                                 Byte = (((Byte & 0xCC) >> 2) | ((Byte & 0x33) << 2));
 257                                 Byte = (((Byte & 0xAA) >> 1) | ((Byte & 0x55) << 1));
 258
 259                                 return Byte;
 260                         }
 261
 262                         /** Function to reverse the byte ordering of the individual bytes in a 16 bit number.
 263                          *
 264                          *  \ingroup Group_BitManip
 265                          *
 266                          *  \param[in] Word  Word of data whose bytes are to be swapped.
 267                          */
 268                         static inline uint16_t SwapEndian_16(const uint16_t Word) ATTR_WARN_UNUSED_RESULT ATTR_CONST;
 269                         static inline uint16_t SwapEndian_16(const uint16_t Word)
 270                         {
 271                                 uint8_t Temp;
 272
 273                                 union
 274                                 {
 275                                         uint16_t Word;
 276                                         uint8_t  Bytes[2];
 277                                 } Data;
 278
 279                                 Data.Word = Word;
 280
 281                                 Temp = Data.Bytes[0];
 282                                 Data.Bytes[0] = Data.Bytes[1];
 283                                 Data.Bytes[1] = Temp;
 284
 285                                 return Data.Word;
 286                         }
 287
 288                         /** Function to reverse the byte ordering of the individual bytes in a 32 bit number.
 289                          *
 290                          *  \ingroup Group_BitManip
 291                          *
 292                          *  \param[in] DWord  Double word of data whose bytes are to be swapped.
 293                          */
 294                         static inline uint32_t SwapEndian_32(const uint32_t DWord) ATTR_WARN_UNUSED_RESULT ATTR_CONST;
 295                         static inline uint32_t SwapEndian_32(const uint32_t DWord)
 296                         {
 297                                 uint8_t Temp;
 298
 299                                 union
 300                                 {
 301                                         uint32_t DWord;
 302                                         uint8_t  Bytes[4];
 303                                 } Data;
 304
 305                                 Data.DWord = DWord;
 306
 307                                 Temp = Data.Bytes[0];
 308                                 Data.Bytes[0] = Data.Bytes[3];
 309                                 Data.Bytes[3] = Temp;
 310
 311                                 Temp = Data.Bytes[1];
 312                                 Data.Bytes[1] = Data.Bytes[2];
 313                                 Data.Bytes[2] = Temp;
 314
 315                                 return Data.DWord;
 316                         }
 317
 318                         /** Function to reverse the byte ordering of the individual bytes in a n byte number.
 319                          *
 320                          *  \ingroup Group_BitManip
 321                          *
 322                          *  \param[in,out] Data   Pointer to a number containing an even number of bytes to be reversed.
 323                          *  \param[in]     Bytes  Length of the data in bytes.
 324                          */
 325                         static inline void SwapEndian_n(void* Data,
 326                                                         uint8_t Bytes) ATTR_NON_NULL_PTR_ARG(1);
 327                         static inline void SwapEndian_n(void* Data,
 328                                                         uint8_t Bytes)
 329                         {
 330                                 uint8_t* CurrDataPos = (uint8_t*)Data;
 331
 332                                 while (Bytes > 1)
 333                                 {
 334                                         uint8_t Temp = *CurrDataPos;
 335                                         *CurrDataPos = *(CurrDataPos + Bytes - 1);
 336                                         *(CurrDataPos + Bytes - 1) = Temp;
 337
 338                                         CurrDataPos++;
 339                                         Bytes -= 2;
 340                                 }
 341                         }
 342
 343 #endif
 344
 345 /** @} */
 346