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                 #if defined(USE_LUFA_CONFIG_HEADER)
  71                         #include "LUFAConfig.h"
  72                 #endif
  73
  74                 #include "Architectures.h"
  75                 #include "Attributes.h"
  76                 #include "BoardTypes.h"
  77
  78         /* Architecture specific utility includes: */
  79                 #if defined(__DOXYGEN__)
  80                         /** Type define for an unsigned integer the same width as the selected architecture's machine register.
  81                          *  This is distinct from the non-specific standard int data type, whose width is machine dependant but
  82                          *  which may not reflect the actual machine register width on some targets (e.g. AVR8).
  83                          */
  84                         typedef MACHINE_REG_t uint_reg_t;
  85                 #elif (ARCH == ARCH_AVR8)
  86                         #include <avr/io.h>
  87                         #include <avr/interrupt.h>
  88                         #include <avr/pgmspace.h>
  89                         #include <avr/eeprom.h>
  90                         #include <avr/boot.h>
  91                         #include <util/delay.h>
  92
  93                         typedef uint8_t uint_reg_t;
  94
  95                         #define ARCH_HAS_EEPROM_ADDRESS_SPACE
  96                         #define ARCH_HAS_FLASH_ADDRESS_SPACE
  97                         #define ARCH_HAS_MULTI_ADDRESS_SPACE
  98                         #define ARCH_LITTLE_ENDIAN
  99
 100                         #include "Endianness.h"
 101                 #elif (ARCH == ARCH_UC3)
 102                         #include <avr32/io.h>
 103
 104                         // === TODO: Find abstracted way to handle these ===
 105                         #define PROGMEM                  const
 106                         #define pgm_read_byte(x)         *x
 107                         #define memcmp_P(...)            memcmp(__VA_ARGS__)
 108                         #define memcpy_P(...)            memcpy(__VA_ARGS__)
 109                         // =================================================
 110
 111                         typedef uint32_t uint_reg_t;
 112
 113                         #define ARCH_BIG_ENDIAN
 114
 115                         #include "Endianness.h"
 116                 #else
 117                         #error Unknown device architecture specified.
 118                 #endif
 119
 120         /* Public Interface - May be used in end-application: */
 121                 /* Macros: */
 122                         /** Macro for encasing other multi-statement macros. This should be used along with an opening brace
 123                          *  before the start 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 MACROS                  do
 128
 129                         /** Macro for encasing other multi-statement macros. This should be used along with a preceding closing
 130                          *  brace at the end of any multi-statement macro, so that the macros contents as a whole are treated
 131                          *  as a discrete block and not as a list of separate statements which may cause problems when used as
 132                          *  a block (such as inline \c if statements).
 133                          */
 134                         #define MACROE                  while (0)
 135
 136                         /** Convenience macro to determine the larger of two values.
 137                          *
 138                          *  \note This macro should only be used with operands that do not have side effects from being evaluated
 139                          *        multiple times.
 140                          *
 141                          *  \param[in] x  First value to compare
 142                          *  \param[in] y  First value to compare
 143                          *
 144                          *  \return The larger of the two input parameters
 145                          */
 146                         #if !defined(MAX) || defined(__DOXYGEN__)
 147                                 #define MAX(x, y)               ((x > y) ? x : y)
 148                         #endif
 149
 150                         /** Convenience macro to determine the smaller of two values.
 151                          *
 152                          *  \note This macro should only be used with operands that do not have side effects from being evaluated
 153                          *        multiple times.
 154                          *
 155                          *  \param[in] x  First value to compare
 156                          *  \param[in] y  First value to compare
 157                          *
 158                          *  \return The smaller of the two input parameters
 159                          */
 160                         #if !defined(MIN) || defined(__DOXYGEN__)
 161                                 #define MIN(x, y)               ((x < y) ? x : y)
 162                         #endif
 163
 164                         #if (ARCH == ARCH_AVR8) || defined(__DOXYGEN__)
 165                                 /** Defines a volatile \c NOP statement which cannot be optimized out by the compiler, and thus can always
 166                                  *  be set as a breakpoint in the resulting code. Useful for debugging purposes, where the optimiser
 167                                  *  removes/reorders code to the point where break points cannot reliably be set.
 168                                  *
 169                                  *  \note This macro is not available for all architectures.
 170                                  *
 171                                  *  \ingroup Group_Debugging
 172                                  */
 173                                 #define JTAG_DEBUG_POINT()      __asm__ __volatile__ ("NOP" ::)
 174
 175                                 /** Defines an explicit JTAG break point in the resulting binary via the assembly \c BREAK statement. When
 176                                  *  a JTAG is used, this causes the program execution to halt when reached until manually resumed.
 177                                  *
 178                                  *  \note This macro is not available for all architectures.
 179                                  *
 180                                  *  \ingroup Group_Debugging
 181                                  */
 182                                 #define JTAG_DEBUG_BREAK()      __asm__ __volatile__ ("BREAK" ::)
 183
 184                                 /** Macro for testing condition "x" and breaking via \ref JTAG_DEBUG_BREAK() if the condition is false.
 185                                  *
 186                                  *  \note This macro is not available for all architectures.
 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                                  *  \note This macro is not available for all architectures.
 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
 210                                 #if !defined(pgm_read_ptr) || defined(__DOXYGEN__)
 211                                         /** Reads a pointer out of PROGMEM space on the AVR8 architecture. This is currently a wrapper for the
 212                                          *  avr-libc \c pgm_read_ptr() macro with a \c void* cast, so that its value can be assigned directly
 213                                          *  to a pointer variable or used in pointer arithmetic without further casting in C. In a future
 214                                          *  avr-libc distribution this will be part of the standard API and will be implemented in a more formal
 215                                          *  manner.
 216                                          *
 217                                          *  \note This macro is not available for all architectures.
 218                                          *
 219                                          *  \param[in] Address  Address of the pointer to read.
 220                                          *
 221                                          *  \return Pointer retrieved from PROGMEM space.
 222                                          */
 223                                         #define pgm_read_ptr(Address)        (void*)pgm_read_word(Address)
 224                                 #endif
 225                         #endif
 226
 227                         /** Forces GCC to use pointer indirection (via the device's pointer register pairs) when accessing the given
 228                          *  struct pointer. In some cases GCC will emit non-optimal assembly code when accessing a structure through
 229                          *  a pointer, resulting in a larger binary. When this macro is used on a (non \c const) structure pointer before
 230                          *  use, it will force GCC to use pointer indirection on the elements rather than direct store and load
 231                          *  instructions.
 232                          *
 233                          *  \param[in, out] StructPtr  Pointer to a structure which is to be forced into indirect access mode.
 234                          */
 235                         #define GCC_FORCE_POINTER_ACCESS(StructPtr) __asm__ __volatile__("" : "=b" (StructPtr) : "0" (StructPtr))
 236
 237                         /** Forces GCC to create a memory barrier, ensuring that memory accesses are not reordered past the barrier point.
 238                          *  This can be used before ordering-critical operations, to ensure that the compiler does not re-order the resulting
 239                          *  assembly output in an unexpected manner on sections of code that are ordering-specific.
 240                          */
 241                         #define GCC_MEMORY_BARRIER()                __asm__ __volatile__("" ::: "memory");
 242
 243                         /** Evaluates to boolean true if the specified value can be determined at compile time to be a constant value
 244                          *  when compiling under GCC.
 245                          *
 246                          *  \param[in] x  Value to check compile time constantness of.
 247                          *
 248                          *  \return Boolean true if the given value is known to be a compile time constant.
 249                          */
 250                         #define GCC_IS_COMPILE_CONST(x)             __builtin_constant_p(x)
 251
 252                         #if !defined(ISR) || defined(__DOXYGEN__)
 253                                 /** Macro for the definition of interrupt service routines, so that the compiler can insert the required
 254                                  *  prologue and epilogue code to properly manage the interrupt routine without affecting the main thread's
 255                                  *  state with unintentional side-effects.
 256                                  *
 257                                  *  Interrupt handlers written using this macro may still need to be registered with the microcontroller's
 258                                  *  Interrupt Controller (if present) before they will properly handle incoming interrupt events.
 259                                  *
 260                                  *  \note This macro is only supplied on some architectures, where the standard library does not include a valid
 261                                  *        definition. If an existing definition exists, the alternative definition here will be ignored.
 262                                  *
 263                                  *  \ingroup Group_GlobalInt
 264                                  *
 265                                  *  \param Name  Unique name of the interrupt service routine.
 266                                  */
 267                                 #define ISR(Name, ...)                  void Name (void) __attribute__((__interrupt__)) __VA_ARGS__; void Name (void)
 268                         #endif
 269
 270                 /* Inline Functions: */
 271                         /** Function to reverse the individual bits in a byte - i.e. bit 7 is moved to bit 0, bit 6 to bit 1,
 272                          *  etc.
 273                          *
 274                          *  \param[in] Byte  Byte of data whose bits are to be reversed.
 275                          */
 276                         static inline uint8_t BitReverse(uint8_t Byte) ATTR_WARN_UNUSED_RESULT ATTR_CONST;
 277                         static inline uint8_t BitReverse(uint8_t Byte)
 278                         {
 279                                 Byte = (((Byte & 0xF0) >> 4) | ((Byte & 0x0F) << 4));
 280                                 Byte = (((Byte & 0xCC) >> 2) | ((Byte & 0x33) << 2));
 281                                 Byte = (((Byte & 0xAA) >> 1) | ((Byte & 0x55) << 1));
 282
 283                                 return Byte;
 284                         }
 285
 286                         /** Function to perform a blocking delay for a specified number of milliseconds. The actual delay will be
 287                          *  at a minimum the specified number of milliseconds, however due to loop overhead and internal calculations
 288                          *  may be slightly higher.
 289                          *
 290                          *  \param[in] Milliseconds  Number of milliseconds to delay
 291                          */
 292                         static inline void Delay_MS(uint8_t Milliseconds) ATTR_ALWAYS_INLINE;
 293                         static inline void Delay_MS(uint8_t Milliseconds)
 294                         {
 295                                 #if (ARCH == ARCH_AVR8)
 296                                 if (GCC_IS_COMPILE_CONST(Milliseconds))
 297                                 {
 298                                         _delay_ms(Milliseconds);
 299                                 }
 300                                 else
 301                                 {
 302                                         while (Milliseconds--)
 303                                           _delay_ms(1);
 304                                 }
 305                                 #elif (ARCH == ARCH_UC3)
 306                                 while (Milliseconds--)
 307                                 {
 308                                         __builtin_mtsr(AVR32_COUNT, 0);
 309                                         while (__builtin_mfsr(AVR32_COUNT) < (F_CPU / 1000));
 310                                 }
 311                                 #endif
 312                         }
 313
 314                         /** Retrieves a mask which contains the current state of the global interrupts for the device. This
 315                          *  value can be stored before altering the global interrupt enable state, before restoring the
 316                          *  flag(s) back to their previous values after a critical section using \ref SetGlobalInterruptMask().
 317                          *
 318                          *  \ingroup Group_GlobalInt
 319                          *
 320                          *  \return  Mask containing the current Global Interrupt Enable Mask bit(s).
 321                          */
 322                         static inline uint_reg_t GetGlobalInterruptMask(void) ATTR_ALWAYS_INLINE ATTR_WARN_UNUSED_RESULT;
 323                         static inline uint_reg_t GetGlobalInterruptMask(void)
 324                         {
 325                                 GCC_MEMORY_BARRIER();
 326
 327                                 #if (ARCH == ARCH_AVR8)
 328                                 return SREG;
 329                                 #elif (ARCH == ARCH_UC3)
 330                                 return __builtin_mfsr(AVR32_SR);
 331                                 #endif
 332
 333                                 GCC_MEMORY_BARRIER();
 334                         }
 335
 336                         /** Sets the global interrupt enable state of the microcontroller to the mask passed into the function.
 337                          *  This can be combined with \ref GetGlobalInterruptMask() to save and restore the Global Interrupt Enable
 338                          *  Mask bit(s) of the device after a critical section has completed.
 339                          *
 340                          *  \ingroup Group_GlobalInt
 341                          *
 342                          *  \param[in] GlobalIntState  Global Interrupt Enable Mask value to use
 343                          */
 344                         static inline void SetGlobalInterruptMask(const uint_reg_t GlobalIntState) ATTR_ALWAYS_INLINE;
 345                         static inline void SetGlobalInterruptMask(const uint_reg_t GlobalIntState)
 346                         {
 347                                 GCC_MEMORY_BARRIER();
 348
 349                                 #if (ARCH == ARCH_AVR8)
 350                                 SREG = GlobalIntState;
 351                                 #elif (ARCH == ARCH_UC3)
 352                                 if (GlobalIntState & AVR32_SR_GM)
 353                                   __builtin_ssrf(AVR32_SR_GM_OFFSET);
 354                                 else
 355                                   __builtin_csrf(AVR32_SR_GM_OFFSET);
 356                                 #endif
 357
 358                                 GCC_MEMORY_BARRIER();
 359                         }
 360
 361                         /** Enables global interrupt handling for the device, allowing interrupts to be handled.
 362                          *
 363                          *  \ingroup Group_GlobalInt
 364                          */
 365                         static inline void GlobalInterruptEnable(void) ATTR_ALWAYS_INLINE;
 366                         static inline void GlobalInterruptEnable(void)
 367                         {
 368                                 GCC_MEMORY_BARRIER();
 369
 370                                 #if (ARCH == ARCH_AVR8)
 371                                 sei();
 372                                 #elif (ARCH == ARCH_UC3)
 373                                 __builtin_csrf(AVR32_SR_GM_OFFSET);
 374                                 #endif
 375
 376                                 GCC_MEMORY_BARRIER();
 377                         }
 378
 379                         /** Disabled global interrupt handling for the device, preventing interrupts from being handled.
 380                          *
 381                          *  \ingroup Group_GlobalInt
 382                          */
 383                         static inline void GlobalInterruptDisable(void) ATTR_ALWAYS_INLINE;
 384                         static inline void GlobalInterruptDisable(void)
 385                         {
 386                                 GCC_MEMORY_BARRIER();
 387
 388                                 #if (ARCH == ARCH_AVR8)
 389                                 cli();
 390                                 #elif (ARCH == ARCH_UC3)
 391                                 __builtin_ssrf(AVR32_SR_GM_OFFSET);
 392                                 #endif
 393
 394                                 GCC_MEMORY_BARRIER();
 395                         }
 396
 397 #endif
 398
 399 /** @} */
 400