Common.h 11.8 KB
Newer Older
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
17
18
  permission notice and warranty disclaimer appear in supporting
  documentation, and that the name of the author not be used in
  advertising or publicity pertaining to distribution of the
19
20
21
22
23
24
25
26
27
28
29
30
31
  software without specific, written prior permission.

  The author disclaim all warranties with regard to this
  software, including all implied warranties of merchantability
  and fitness.  In no event shall the author be liable for any
  special, indirect or consequential damages or any damages
  whatsoever resulting from loss of use, data or profits, whether
  in an action of contract, negligence or other tortious action,
  arising out of or in connection with the use or performance of
  this software.
*/

/** \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
41
42
43
44
45
 *
 *  Common utility headers containing macros, functions, enums and types which are common to all
 *  aspects of the library.
 *
 *  @{
 */

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
59
#ifndef __LUFA_COMMON_H__
#define __LUFA_COMMON_H__
60

61
62
63
64
65
	/* Macros: */
		#if !defined(__DOXYGEN__)
			#define __INCLUDE_FROM_COMMON_H
		#endif
		
66
	/* Includes: */
67
68
		#include <stdint.h>
		#include <stdbool.h>
69
		#include <string.h>
70
		#include <stddef.h>
71
		
72
		#include "Architectures.h"
73
74
		#include "Attributes.h"
		#include "BoardTypes.h"
75
76
77
78
79
80
81
		
	/* Architecture specific utility includes: */
		#if (ARCH == ARCH_AVR8)
			#include <avr/io.h>
			#include <avr/interrupt.h>
			#include <avr/pgmspace.h>
			#include <avr/eeprom.h>
82
			#include <avr/boot.h>
83
84
			#include <util/atomic.h>
			#include <util/delay.h>
85
86
87
88
89
90
91
92
93
94
			
			typedef uint8_t uintN_t;
			typedef int8_t  intN_t;
		#elif (ARCH == ARCH_UC3B)
			#include <avr32/io.h>

			typedef uint32_t uintN_t;
			typedef int32_t  intN_t;
			
			#warning The UC3B architecture support is currently experimental and incomplete!
95
		#endif
96
97

	/* Public Interface - May be used in end-application: */
98
		/* Macros: */
99
100
101
			/** Macro for encasing other multi-statement macros. This should be used along with an opening brace
			 *  before the start of any multi-statement macro, so that the macros contents as a whole are treated
			 *  as a discrete block and not as a list of separate statements which may cause problems when used as
102
			 *  a block (such as inline \c if statements).
103
104
105
106
107
108
			 */
			#define MACROS                  do

			/** Macro for encasing other multi-statement macros. This should be used along with a preceding closing
			 *  brace at the end of any multi-statement macro, so that the macros contents as a whole are treated
			 *  as a discrete block and not as a list of separate statements which may cause problems when used as
109
			 *  a block (such as inline \c if statements).
110
111
			 */
			#define MACROE                  while (0)
112

113
114
115
116
117
118
119
120
121
122
			/** Convenience macro to determine the larger of two values.
			 *
			 *  \note This macro should only be used with operands that do not have side effects from being evaluated
			 *        multiple times.
			 *
			 *  \param[in] x  First value to compare
			 *  \param[in] y  First value to compare
			 *
			 *  \return The larger of the two input parameters
			 */
123
124
125
			#if !defined(MAX) || defined(__DOXYGEN__)
				#define MAX(x, y)               ((x > y) ? x : y)
			#endif
126
127
128
129
130
131
132
133
134
135
136

			/** Convenience macro to determine the smaller of two values.
			 *
			 *  \note This macro should only be used with operands that do not have side effects from being evaluated
			 *        multiple times.
			 *
			 *  \param[in] x  First value to compare
			 *  \param[in] y  First value to compare
			 *
			 *  \return The smaller of the two input parameters
			 */
137
138
139
			#if !defined(MIN) || defined(__DOXYGEN__)
				#define MIN(x, y)               ((x < y) ? x : y)
			#endif
140

141
			#if (ARCH == ARCH_AVR8) || defined(__DOXYGEN__)
142
143
144
145
146
147
148
				/** Defines a volatile \c NOP statement which cannot be optimized out by the compiler, and thus can always
				 *  be set as a breakpoint in the resulting code. Useful for debugging purposes, where the optimiser
				 *  removes/reorders code to the point where break points cannot reliably be set.
				 *
				 *  \ingroup Group_Debugging
				 */
				#define JTAG_DEBUG_POINT()      __asm__ __volatile__ ("NOP" ::)
149

150
151
152
153
154
155
156
157
				/** Defines an explicit JTAG break point in the resulting binary via the assembly \c BREAK statement. When
				 *  a JTAG is used, this causes the program execution to halt when reached until manually resumed.
				 *
				 *  \ingroup Group_Debugging
				 */
				#define JTAG_DEBUG_BREAK()      __asm__ __volatile__ ("BREAK" ::)

				#if !defined(pgm_read_ptr) || defined(__DOXYGEN__)
158
159
160
161
162
					/** Reads a pointer out of PROGMEM space on the AVR8 architecture. This is currently a wrapper for the
					 *  avr-libc \c pgm_read_ptr() macro with a \c void* cast, so that its value can be assigned directly
					 *  to a pointer variable or used in pointer arithmetic without further casting in C. In a future
					 *  avr-libc distribution this will be part of the standard API and will be implemented in a more formal
					 *  manner.
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
					 *
					 *  \param[in] Addr  Address of the pointer to read.
					 *
					 *  \return Pointer retrieved from PROGMEM space.
					 */
					#define pgm_read_ptr(Addr)    (void*)pgm_read_word(Addr)
				#endif

				/** Macro for testing condition "x" and breaking via \ref JTAG_DEBUG_BREAK() if the condition is false.
				 *
				 *  \param[in] Condition  Condition that will be evaluated,
				 *
				 *  \ingroup Group_Debugging
				*/
				#define JTAG_DEBUG_ASSERT(Condition)    MACROS{ if (!(Condition)) { JTAG_DEBUG_BREAK(); } }MACROE
178

179
				/** Macro for testing condition "x" and writing debug data to the stdout stream if \c false. The stdout stream
180
181
				 *  must be pre-initialized before this macro is run and linked to an output device, such as the microcontroller's
				 *  USART peripheral.
182
183
184
185
186
187
188
189
190
191
192
				 *
				 *  The output takes the form "{FILENAME}: Function {FUNCTION NAME}, Line {LINE NUMBER}: Assertion {Condition} failed."
				 *
				 *  \param[in] Condition  Condition that will be evaluated,
				 *
				 *  \ingroup Group_Debugging
				 */
				#define STDOUT_ASSERT(Condition)        MACROS{ if (!(x)) { printf_P(PSTR("%s: Function \"%s\", Line %d: "   \
				                                                "Assertion \"%s\" failed.\r\n"),     \
				                                                __FILE__, __func__, __LINE__, #Condition); } }MACROE
			#endif
193
			
194
			/** Forces GCC to use pointer indirection (via the device's pointer register pairs) when accessing the given
195
			 *  struct pointer. In some cases GCC will emit non-optimal assembly code when accessing a structure through
196
			 *  a pointer, resulting in a larger binary. When this macro is used on a (non \c const) structure pointer before
197
198
199
200
201
202
			 *  use, it will force GCC to use pointer indirection on the elements rather than direct store and load
			 *  instructions.
			 *
			 *  \param[in, out] StructPtr  Pointer to a structure which is to be forced into indirect access mode.
			 */
			#define GCC_FORCE_POINTER_ACCESS(StructPtr) __asm__ __volatile__("" : "=b" (StructPtr) : "0" (StructPtr))
203
204
205

			/** Swaps the byte ordering of a 16-bit value at compile time. Do not use this macro for swapping byte orderings
			 *  of dynamic values computed at runtime, use \ref SwapEndian_16() instead. The result of this macro can be used
206
			 *  inside struct or other variable initializers outside of a function, something that is not possible with the
207
208
209
210
211
212
213
214
215
216
			 *  inline function variant.
			 *
			 *  \param[in]  x  16-bit value whose byte ordering is to be swapped.
			 *
			 *  \return Input value with the byte ordering reversed.
			 */
			#define SWAPENDIAN_16(x)          ((((x) & 0xFF00) >> 8) | (((x) & 0x00FF) << 8))

			/** Swaps the byte ordering of a 32-bit value at compile time. Do not use this macro for swapping byte orderings
			 *  of dynamic values computed at runtime- use \ref SwapEndian_32() instead. The result of this macro can be used
217
			 *  inside struct or other variable initializers outside of a function, something that is not possible with the
218
219
220
221
222
223
224
225
			 *  inline function variant.
			 *
			 *  \param[in]  x  32-bit value whose byte ordering is to be swapped.
			 *
			 *  \return Input value with the byte ordering reversed.
			 */
			#define SWAPENDIAN_32(x)          ((((x) & 0xFF000000UL) >> 24UL) | (((x) & 0x00FF0000UL) >> 8UL) | \
			                                   (((x) & 0x0000FF00UL) << 8UL)  | (((x) & 0x000000FFUL) << 24UL))
226

227
228
229
230
231
232
		/* Inline Functions: */
			/** Function to reverse the individual bits in a byte - i.e. bit 7 is moved to bit 0, bit 6 to bit 1,
			 *  etc.
			 *
			 *  \ingroup Group_BitManip
			 *
233
			 *  \param[in] Byte  Byte of data whose bits are to be reversed.
234
235
236
237
238
239
240
241
242
243
			 */
			static inline uint8_t BitReverse(uint8_t Byte) ATTR_WARN_UNUSED_RESULT ATTR_CONST;
			static inline uint8_t BitReverse(uint8_t Byte)
			{
				Byte = (((Byte & 0xF0) >> 4) | ((Byte & 0x0F) << 4));
				Byte = (((Byte & 0xCC) >> 2) | ((Byte & 0x33) << 2));
				Byte = (((Byte & 0xAA) >> 1) | ((Byte & 0x55) << 1));

				return Byte;
			}
244

245
246
247
248
			/** Function to reverse the byte ordering of the individual bytes in a 16 bit number.
			 *
			 *  \ingroup Group_BitManip
			 *
249
			 *  \param[in] Word  Word of data whose bytes are to be swapped.
250
			 */
251
252
			static inline uint16_t SwapEndian_16(const uint16_t Word) ATTR_WARN_UNUSED_RESULT ATTR_CONST;
			static inline uint16_t SwapEndian_16(const uint16_t Word)
253
			{
254
255
256
257
258
259
260
				uint8_t Temp;

				union
				{
					uint16_t Word;
					uint8_t  Bytes[2];
				} Data;
261

262
				Data.Word = Word;
263

264
265
266
				Temp = Data.Bytes[0];
				Data.Bytes[0] = Data.Bytes[1];
				Data.Bytes[1] = Temp;
267

268
				return Data.Word;
269
270
271
272
273
274
			}

			/** Function to reverse the byte ordering of the individual bytes in a 32 bit number.
			 *
			 *  \ingroup Group_BitManip
			 *
275
			 *  \param[in] DWord  Double word of data whose bytes are to be swapped.
276
			 */
277
278
			static inline uint32_t SwapEndian_32(const uint32_t DWord) ATTR_WARN_UNUSED_RESULT ATTR_CONST;
			static inline uint32_t SwapEndian_32(const uint32_t DWord)
279
			{
280
281
282
283
284
285
286
				uint8_t Temp;

				union
				{
					uint32_t DWord;
					uint8_t  Bytes[4];
				} Data;
287

288
				Data.DWord = DWord;
289

290
291
292
				Temp = Data.Bytes[0];
				Data.Bytes[0] = Data.Bytes[3];
				Data.Bytes[3] = Temp;
293

294
295
296
				Temp = Data.Bytes[1];
				Data.Bytes[1] = Data.Bytes[2];
				Data.Bytes[2] = Temp;
297

298
				return Data.DWord;
299
300
301
302
303
304
			}

			/** Function to reverse the byte ordering of the individual bytes in a n byte number.
			 *
			 *  \ingroup Group_BitManip
			 *
305
306
			 *  \param[in,out] Data   Pointer to a number containing an even number of bytes to be reversed.
			 *  \param[in]     Bytes  Length of the data in bytes.
307
			 */
308
309
310
311
			static inline void SwapEndian_n(void* Data,
			                                uint8_t Bytes) ATTR_NON_NULL_PTR_ARG(1);
			static inline void SwapEndian_n(void* Data,
			                                uint8_t Bytes)
312
			{
313
				uint8_t* CurrDataPos = (uint8_t*)Data;
314

315
				while (Bytes > 1)
316
317
318
319
320
321
322
323
324
325
326
327
328
				{
					uint8_t Temp = *CurrDataPos;
					*CurrDataPos = *(CurrDataPos + Bytes - 1);
					*(CurrDataPos + Bytes - 1) = Temp;

					CurrDataPos++;
					Bytes -= 2;
				}
			}

#endif

/** @} */
329