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_GlobalInt Global Interrupt Macros
  53  *  \brief Convenience macros for the management of interrupts globally within the device.
  54  *
  55  *  Macros and functions to create and control global interrupts within the device.
  56  */
  57
  58 #ifndef __LUFA_COMMON_H__
  59 #define __LUFA_COMMON_H__
  60
  61         /* Macros: */
  62                 #define __INCLUDE_FROM_COMMON_H
  63
  64         /* Includes: */
  65                 #include <stdint.h>
  66                 #include <stdbool.h>
  67                 #include <string.h>
  68                 #include <stddef.h>
  69
  70                 #include "Architectures.h"
  71                 #include "Attributes.h"
  72                 #include "BoardTypes.h"
  73
  74         /* Architecture specific utility includes: */
  75                 #if defined(__DOXYGEN__)
  76                         /** Type define for an unsigned integer the same width as the selected architecture's machine register. */
  77                         typedef MACHINE_REG_t uint_reg_t;
  78                 #elif (ARCH == ARCH_AVR8)
  79                         #include <avr/io.h>
  80                         #include <avr/interrupt.h>
  81                         #include <avr/pgmspace.h>
  82                         #include <avr/eeprom.h>
  83                         #include <avr/boot.h>
  84                         #include <util/delay.h>
  85
  86                         typedef uint8_t uint_reg_t;
  87
  88                         #define ARCH_HAS_EEPROM_ADDRESS_SPACE
  89                         #define ARCH_HAS_FLASH_ADDRESS_SPACE
  90                         #define ARCH_HAS_MULTI_ADDRESS_SPACE
  91                         #define ARCH_LITTLE_ENDIAN
  92
  93                         #include "Endianness.h"
  94                 #elif (ARCH == ARCH_UC3)
  95                         #include <avr32/io.h>
  96
  97                         // === TODO: Find abstracted way to handle these ===
  98                         #define PROGMEM                  const
  99                         #define pgm_read_byte(x)         *x
 100                         #define memcmp_P(...)            memcmp(__VA_ARGS__)
 101                         #define memcpy_P(...)            memcpy(__VA_ARGS__)
 102                         // ==================================================
 103
 104                         typedef uint32_t uint_reg_t;
 105
 106                         #define ARCH_BIG_ENDIAN
 107
 108                         #include "Endianness.h"
 109                 #else
 110                         #error Unknown device architecture specified.
 111                 #endif
 112
 113         /* Public Interface - May be used in end-application: */
 114                 /* Macros: */
 115                         /** Macro for encasing other multi-statement macros. This should be used along with an opening brace
 116                          *  before the start of any multi-statement macro, so that the macros contents as a whole are treated
 117                          *  as a discrete block and not as a list of separate statements which may cause problems when used as
 118                          *  a block (such as inline \c if statements).
 119                          */
 120                         #define MACROS                  do
 121
 122                         /** Macro for encasing other multi-statement macros. This should be used along with a preceding closing
 123                          *  brace at the end of any multi-statement macro, so that the macros contents as a whole are treated
 124                          *  as a discrete block and not as a list of separate statements which may cause problems when used as
 125                          *  a block (such as inline \c if statements).
 126                          */
 127                         #define MACROE                  while (0)
 128
 129                         /** Convenience macro to determine the larger of two values.
 130                          *
 131                          *  \note This macro should only be used with operands that do not have side effects from being evaluated
 132                          *        multiple times.
 133                          *
 134                          *  \param[in] x  First value to compare
 135                          *  \param[in] y  First value to compare
 136                          *
 137                          *  \return The larger of the two input parameters
 138                          */
 139                         #if !defined(MAX) || defined(__DOXYGEN__)
 140                                 #define MAX(x, y)               ((x > y) ? x : y)
 141                         #endif
 142
 143                         /** Convenience macro to determine the smaller of two values.
 144                          *
 145                          *  \note This macro should only be used with operands that do not have side effects from being evaluated
 146                          *        multiple times.
 147                          *
 148                          *  \param[in] x  First value to compare
 149                          *  \param[in] y  First value to compare
 150                          *
 151                          *  \return The smaller of the two input parameters
 152                          */
 153                         #if !defined(MIN) || defined(__DOXYGEN__)
 154                                 #define MIN(x, y)               ((x < y) ? x : y)
 155                         #endif
 156
 157                         #if (ARCH == ARCH_AVR8) || defined(__DOXYGEN__)
 158                                 /** Defines a volatile \c NOP statement which cannot be optimized out by the compiler, and thus can always
 159                                  *  be set as a breakpoint in the resulting code. Useful for debugging purposes, where the optimiser
 160                                  *  removes/reorders code to the point where break points cannot reliably be set.
 161                                  *
 162                                  *  \ingroup Group_Debugging
 163                                  */
 164                                 #define JTAG_DEBUG_POINT()      __asm__ __volatile__ ("NOP" ::)
 165
 166                                 /** Defines an explicit JTAG break point in the resulting binary via the assembly \c BREAK statement. When
 167                                  *  a JTAG is used, this causes the program execution to halt when reached until manually resumed.
 168                                  *
 169                                  *  \ingroup Group_Debugging
 170                                  */
 171                                 #define JTAG_DEBUG_BREAK()      __asm__ __volatile__ ("BREAK" ::)
 172
 173                                 #if !defined(pgm_read_ptr) || defined(__DOXYGEN__)
 174                                         /** Reads a pointer out of PROGMEM space on the AVR8 architecture. This is currently a wrapper for the
 175                                          *  avr-libc \c pgm_read_ptr() macro with a \c void* cast, so that its value can be assigned directly
 176                                          *  to a pointer variable or used in pointer arithmetic without further casting in C. In a future
 177                                          *  avr-libc distribution this will be part of the standard API and will be implemented in a more formal
 178                                          *  manner.
 179                                          *
 180                                          *  \param[in] Addr  Address of the pointer to read.
 181                                          *
 182                                          *  \return Pointer retrieved from PROGMEM space.
 183                                          */
 184                                         #define pgm_read_ptr(Addr)    (void*)pgm_read_word(Addr)
 185                                 #endif
 186
 187                                 /** Macro for testing condition "x" and breaking via \ref JTAG_DEBUG_BREAK() if the condition is false.
 188                                  *
 189                                  *  \param[in] Condition  Condition that will be evaluated,
 190                                  *
 191                                  *  \ingroup Group_Debugging
 192                                 */
 193                                 #define JTAG_DEBUG_ASSERT(Condition)    MACROS{ if (!(Condition)) { JTAG_DEBUG_BREAK(); } }MACROE
 194
 195                                 /** Macro for testing condition "x" and writing debug data to the stdout stream if \c false. The stdout stream
 196                                  *  must be pre-initialized before this macro is run and linked to an output device, such as the microcontroller's
 197                                  *  USART peripheral.
 198                                  *
 199                                  *  The output takes the form "{FILENAME}: Function {FUNCTION NAME}, Line {LINE NUMBER}: Assertion {Condition} failed."
 200                                  *
 201                                  *  \param[in] Condition  Condition that will be evaluated,
 202                                  *
 203                                  *  \ingroup Group_Debugging
 204                                  */
 205                                 #define STDOUT_ASSERT(Condition)        MACROS{ if (!(x)) { printf_P(PSTR("%s: Function \"%s\", Line %d: "   \
 206                                                                                 "Assertion \"%s\" failed.\r\n"),     \
 207                                                                                 __FILE__, __func__, __LINE__, #Condition); } }MACROE
 208                         #endif
 209
 210                         /** Forces GCC to use pointer indirection (via the device's pointer register pairs) when accessing the given
 211                          *  struct pointer. In some cases GCC will emit non-optimal assembly code when accessing a structure through
 212                          *  a pointer, resulting in a larger binary. When this macro is used on a (non \c const) structure pointer before
 213                          *  use, it will force GCC to use pointer indirection on the elements rather than direct store and load
 214                          *  instructions.
 215                          *
 216                          *  \param[in, out] StructPtr  Pointer to a structure which is to be forced into indirect access mode.
 217                          */
 218                         #define GCC_FORCE_POINTER_ACCESS(StructPtr) __asm__ __volatile__("" : "=b" (StructPtr) : "0" (StructPtr))
 219
 220                         /** Forces GCC to create a memory barrier, ensuring that memory accesses are not reordered past the barrier point.
 221                          *  This can be used before ordering-critical operations, to ensure that the compiler does not re-order the resulting
 222                          *  assembly output in an unexpected manner on sections of code that are ordering-specific.
 223                          */
 224                         #define GCC_MEMORY_BARRIER()                __asm__ __volatile__("" ::: "memory");
 225
 226                         #if !defined(ISR) || defined(__DOXYGEN__)
 227                                 /** Macro for the definition of interrupt service routines, so that the compiler can insert the required
 228                                  *  prologue and epilogue code to properly manage the interrupt routine without affecting the main thread's
 229                                  *  state with unintentional side-effects.
 230                                  *
 231                                  *  Interrupt handlers written using this macro may still need to be registered with the microcontroller's
 232                                  *  Interrupt Controller (if present) before they will properly handle incoming interrupt events.
 233                                  *
 234                                  *  \note This is supplied on some architectures where the standard library does not include a valid
 235                                  *        definition. If an existing definition exists, the definition here will be ignored.
 236                                  *
 237                                  *  \ingroup Group_GlobalInt
 238                                  *
 239                                  *  \param Name  Unique name of the interrupt service routine.
 240                                  */
 241                                 #define ISR(Name, ...)                  void Name (void) __attribute__((__interrupt__)); void Name (void)
 242                         #endif
 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                          *  \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 perform a blocking delay for a specified number of milliseconds. The actual delay will be
 261                          *  at a minimum the specified number of milliseconds, however due to loop overhead and internal calculations
 262                          *  may be slightly higher.
 263                          *
 264                          *  \param[in] Milliseconds  Number of milliseconds to delay
 265                          */
 266                         static inline void Delay_MS(uint8_t Milliseconds)
 267                         {
 268                                 #if (ARCH == ARCH_AVR8)
 269                                 if (__builtin_constant_p(Milliseconds))
 270                                 {
 271                                         _delay_ms(Milliseconds);
 272                                 }
 273                                 else
 274                                 {
 275                                         while (Milliseconds--)
 276                                           _delay_ms(1);
 277                                 }
 278                                 #elif (ARCH == ARCH_UC3)
 279                                 while (Milliseconds--)
 280                                 {
 281                                         __builtin_mtsr(AVR32_COUNT, 0);
 282                                         while (__builtin_mfsr(AVR32_COUNT) < (F_CPU / 1000));
 283                                 }
 284                                 #endif
 285                         }
 286
 287                         /** Retrieves a mask which contains the current state of the global interrupts for the device. This
 288                          *  value can be stored before altering the global interrupt enable state, before restoring the
 289                          *  flag(s) back to their previous values after a critical section using \ref SetGlobalInterruptMask().
 290                          *
 291                          *  \ingroup Group_GlobalInt
 292                          *
 293                          *  \return  Mask containing the current Global Interrupt Enable Mask bit(s).
 294                          */
 295                         static inline uint_reg_t GetGlobalInterruptMask(void) ATTR_ALWAYS_INLINE ATTR_WARN_UNUSED_RESULT;
 296                         static inline uint_reg_t GetGlobalInterruptMask(void)
 297                         {
 298                                 GCC_MEMORY_BARRIER();
 299
 300                                 #if (ARCH == ARCH_AVR8)
 301                                 return SREG;
 302                                 #elif (ARCH == ARCH_UC3)
 303                                 return __builtin_mfsr(AVR32_SR);
 304                                 #endif
 305
 306                                 GCC_MEMORY_BARRIER();
 307                         }
 308
 309                         /** Sets the global interrupt enable state of the microcontroller to the mask passed into the function.
 310                          *  This can be combined with \ref GetGlobalInterruptMask() to save and restore the Global Interrupt Enable
 311                          *  Mask bit(s) of the device after a critical section has completed.
 312                          *
 313                          *  \ingroup Group_GlobalInt
 314                          *
 315                          *  \param[in] GlobalIntState  Global Interrupt Enable Mask value to use
 316                          */
 317                         static inline void SetGlobalInterruptMask(const uint_reg_t GlobalIntState) ATTR_ALWAYS_INLINE;
 318                         static inline void SetGlobalInterruptMask(const uint_reg_t GlobalIntState)
 319                         {
 320                                 GCC_MEMORY_BARRIER();
 321
 322                                 #if (ARCH == ARCH_AVR8)
 323                                 SREG = GlobalIntState;
 324                                 #elif (ARCH == ARCH_UC3)
 325                                 if (GlobalIntState & AVR32_SR_GM)
 326                                   __builtin_ssrf(AVR32_SR_GM_OFFSET);
 327                                 else
 328                                   __builtin_csrf(AVR32_SR_GM_OFFSET);
 329                                 #endif
 330
 331                                 GCC_MEMORY_BARRIER();
 332                         }
 333
 334                         /** Enables global interrupt handling for the device, allowing interrupts to be handled.
 335                          *
 336                          *  \ingroup Group_GlobalInt
 337                          */
 338                         static inline void GlobalInterruptEnable(void) ATTR_ALWAYS_INLINE;
 339                         static inline void GlobalInterruptEnable(void)
 340                         {
 341                                 GCC_MEMORY_BARRIER();
 342
 343                                 #if (ARCH == ARCH_AVR8)
 344                                 sei();
 345                                 #elif (ARCH == ARCH_UC3)
 346                                 __builtin_csrf(AVR32_SR_GM_OFFSET);
 347                                 #endif
 348
 349                                 GCC_MEMORY_BARRIER();
 350                         }
 351
 352                         /** Disabled global interrupt handling for the device, preventing interrupts from being handled.
 353                          *
 354                          *  \ingroup Group_GlobalInt
 355                          */
 356                         static inline void GlobalInterruptDisable(void) ATTR_ALWAYS_INLINE;
 357                         static inline void GlobalInterruptDisable(void)
 358                         {
 359                                 GCC_MEMORY_BARRIER();
 360
 361                                 #if (ARCH == ARCH_AVR8)
 362                                 cli();
 363                                 #elif (ARCH == ARCH_UC3)
 364                                 __builtin_ssrf(AVR32_SR_GM_OFFSET);
 365                                 #endif
 366
 367                                 GCC_MEMORY_BARRIER();
 368                         }
 369
 370 #endif
 371
 372 /** @} */
 373