diff options
Diffstat (limited to 'LUFA')
| -rw-r--r-- | LUFA/Common/Common.h | 14 | ||||
| -rw-r--r-- | LUFA/Drivers/Misc/RingBuffer.h | 254 | ||||
| -rw-r--r-- | LUFA/ManPages/ChangeLog.txt | 3 | ||||
| -rw-r--r-- | LUFA/ManPages/FutureChanges.txt | 1 |
4 files changed, 269 insertions, 3 deletions
diff --git a/LUFA/Common/Common.h b/LUFA/Common/Common.h index 3860eff67..f2e5e313d 100644 --- a/LUFA/Common/Common.h +++ b/LUFA/Common/Common.h @@ -85,14 +85,14 @@ * * \ingroup Group_Debugging */ - #define JTAG_DEBUG_POINT() __asm__ volatile ("NOP" ::) + #define JTAG_DEBUG_POINT() __asm__ __volatile__ ("NOP" ::) /** Defines an explicit JTAG break point in the resulting binary via the ASM 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" ::) + #define JTAG_DEBUG_BREAK() __asm__ __volatile__ ("BREAK" ::) /** Macro for testing condition "x" and breaking via JTAG_DEBUG_BREAK() if the condition is false. * @@ -111,6 +111,16 @@ #define STDOUT_ASSERT(x) MACROS{ if (!(x)) { printf_P(PSTR("%s: Function \"%s\", Line %d: " \ "Assertion \"%s\" failed.\r\n"), \ __FILE__, __func__, __LINE__, #x); } }MACROE + + /** Forces GCC to use pointer indirection (via the AVR's pointer register pairs) when accessing the given + * struct pointer. In some cases GCC will emit non-optimal assembly code when accessing a structure through + * a pointer, resulting in a larger binary. When this macro is used on a (non-const) structure pointer before + * 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)) #if !defined(pgm_read_ptr) || defined(__DOXYGEN__) /** Reads a pointer out of PROGMEM space. This is currently a wrapper for the avr-libc pgm_read_ptr() diff --git a/LUFA/Drivers/Misc/RingBuffer.h b/LUFA/Drivers/Misc/RingBuffer.h new file mode 100644 index 000000000..30493e33a --- /dev/null +++ b/LUFA/Drivers/Misc/RingBuffer.h @@ -0,0 +1,254 @@ +/*
+ LUFA Library
+ Copyright (C) Dean Camera, 2010.
+
+ dean [at] fourwalledcubicle [dot] com
+ www.lufa-lib.org
+*/
+
+/*
+ Copyright 2010 Dean Camera (dean [at] fourwalledcubicle [dot] com)
+
+ Permission to use, copy, modify, distribute, and sell this
+ software and its documentation for any purpose is hereby granted
+ without fee, provided that the above copyright notice appear in
+ all copies and that both that the copyright notice and this
+ 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
+ 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
+ * \brief Lightweight ring buffer, for fast insertion/deletion.
+ *
+ * Lightweight ring buffer, for fast insertion/deletion. Multiple buffers can be created of
+ * different sizes to suit different needs.
+ *
+ * Note that for each buffer, insertion and removal operations may occur at the same time (via
+ * a multithreaded ISR based system) however the same kind of operation (two or more insertions
+ * or deletions) must not overlap. If there is possibility of two or more of the same kind of
+ * operating occuring at the same point in time, atomic (mutex) locking should be used.
+ */
+
+/** \ingroup Group_MiscDrivers
+ * @defgroup Group_RingBuff Generic Byte Ring Buffer - LUFA/Drivers/Misc/RingBuffer.h
+ *
+ * \section Sec_Dependencies Module Source Dependencies
+ * The following files must be built with any user project that uses this module:
+ * - None
+ *
+ * \section Module Description
+ * Lightweight ring buffer, for fast insertion/deletion. Multiple buffers can be created of
+ * different sizes to suit different needs.
+ *
+ * Note that for each buffer, insertion and removal operations may occur at the same time (via
+ * a multithreaded ISR based system) however the same kind of operation (two or more insertions
+ * or deletions) must not overlap. If there is possibility of two or more of the same kind of
+ * operating occuring at the same point in time, atomic (mutex) locking should be used.
+ *
+ * Example Usage:
+ * \code
+ * // Create the buffer structure and its underlying storage array
+ * RingBuff_t Buffer;
+ * uint8_t BufferData[128];
+ *
+ * // Initialise the buffer with the created storage array
+ * RingBuffer_InitBuffer(&Buffer, BufferData, sizeof(BufferData));
+ *
+ * // Insert some data into the buffer
+ * RingBuffer_Insert(Buffer, 'H');
+ * RingBuffer_Insert(Buffer, 'E');
+ * RingBuffer_Insert(Buffer, 'L');
+ * RingBuffer_Insert(Buffer, 'L');
+ * RingBuffer_Insert(Buffer, 'O');
+ *
+ * // Cache the number of stored bytes in the buffer
+ * uint16_t BufferCount = RingBuffer_GetCount(&Buffer);
+ *
+ * // Printer stored data length
+ * printf("Buffer Length: %d, Buffer Data:\r\n", BufferCount);
+ *
+ * // Print contents of the buffer one character at a time
+ * while (BufferCount--)
+ * putc(RingBuffer_Remove(&Buffer));
+ * \endcode
+ *
+ * @{
+ */
+
+#ifndef __RING_BUFF_H__
+#define __RING_BUFF_H__
+
+ /* Includes: */
+ #include <util/atomic.h>
+ #include <stdint.h>
+ #include <stdbool.h>
+
+ #include <LUFA/Common/Common.h>
+
+ /* Type Defines: */
+ /** Type define for a new ring buffer object. Buffers should be initialized via a call to
+ * \ref RingBuffer_InitBuffer() before use.
+ */
+ typedef struct
+ {
+ uint8_t* In; /**< Current storage location in the circular buffer */
+ uint8_t* Out; /**< Current retrieval location in the circular buffer */
+ uint8_t* Start; /** Pointer to the start of the buffer's underlying storage array */
+ uint8_t* End; /** Pointer to the end of the buffer's underlying storage array */
+ uint8_t Size; /** Size of the buffer's underlying storage array */
+ uint16_t Count; /** Number of bytes currently stored in the buffer */
+ } RingBuff_t;
+
+ /* Inline Functions: */
+ /** Initializes a ring buffer ready for use. Buffers must be initialized via this function
+ * before any operations are called upon them. Already initialized buffers may be reset
+ * by re-initializing them using this function.
+ *
+ * \param[out] Buffer Pointer to a ring buffer structure to initialize
+ * \param[out] DataPtr Pointer to a global array that will hold the data stored into the ring buffer
+ * \param[out] Size Maximum number of bytes that can be stored in the underlying data array
+ */
+ static inline void RingBuffer_InitBuffer(RingBuff_t* Buffer, uint8_t* const DataPtr, const uint16_t Size)
+ {
+ ATOMIC_BLOCK(ATOMIC_RESTORESTATE)
+ {
+ GCC_FORCE_POINTER_ACCESS(Buffer);
+
+ Buffer->In = DataPtr;
+ Buffer->Out = DataPtr;
+ Buffer->Start = &DataPtr[0];
+ Buffer->End = &DataPtr[Size];
+ Buffer->Size = Size;
+ Buffer->Count = 0;
+ }
+ }
+
+ /** Retrieves the minimum number of bytes stored in a particular buffer. This value is computed
+ * by entering an atomic lock on the buffer while the IN and OUT locations are fetched, so that
+ * the buffer cannot be modified while the computation takes place. This value should be cached
+ * when reading out the contents of the buffer, so that as small a time as possible is spent
+ * in an atomic lock.
+ *
+ * \note The value returned by this function is guaranteed to only be the minimum number of bytes
+ * stored in the given buffer; this value may change as other threads write new data and so
+ * the returned number should be used only to determine how many successive reads may safely
+ * be performed on the buffer.
+ *
+ * \param[in] Buffer Pointer to a ring buffer structure whose count is to be computed
+ */
+ static inline uint16_t RingBuffer_GetCount(RingBuff_t* const Buffer)
+ {
+ uint16_t Count;
+
+ ATOMIC_BLOCK(ATOMIC_RESTORESTATE)
+ {
+ Count = Buffer->Count;
+ }
+
+ return Count;
+ }
+
+ /** Atomically determines if the specified ring buffer contains any free space. This should
+ * be tested before storing data to the buffer, to ensure that no data is lost due to a
+ * buffer overrun.
+ *
+ * \param[in,out] Buffer Pointer to a ring buffer structure to insert into
+ *
+ * \return Boolean true if the buffer contains no free space, false otherwise
+ */
+ static inline bool RingBuffer_IsFull(RingBuff_t* const Buffer)
+ {
+ return (RingBuffer_GetCount(Buffer) == Buffer->Size);
+ }
+
+ /** Atomically determines if the specified ring buffer contains any data. This should
+ * be tested before removing data from the buffer, to ensure that the buffer does not
+ * underflow.
+ *
+ * If the data is to be removed in a loop, store the total number of bytes stored in the
+ * buffer (via a call to the \ref RingBuffer_GetCount() function) in a temporary variable
+ * to reduce the time spent in atomicity locks.
+ *
+ * \param[in,out] Buffer Pointer to a ring buffer structure to insert into
+ *
+ * \return Boolean true if the buffer contains no free space, false otherwise
+ */
+ static inline bool RingBuffer_IsEmpty(RingBuff_t* const Buffer)
+ {
+ return (RingBuffer_GetCount(Buffer) == 0);
+ }
+
+ /** Inserts an element into the ring buffer.
+ *
+ * \note Only one execution thread (main program thread or an ISR) may insert into a single buffer
+ * otherwise data corruption may occur. Insertion and removal may occur from different execution
+ * threads.
+ *
+ * \param[in,out] Buffer Pointer to a ring buffer structure to insert into
+ * \param[in] Data Data element to insert into the buffer
+ */
+ static inline void RingBuffer_Insert(RingBuff_t* const Buffer,
+ const uint8_t Data)
+ {
+ *Buffer->In = Data;
+
+ if (++Buffer->In == Buffer->End)
+ Buffer->In = Buffer->Start;
+
+ ATOMIC_BLOCK(ATOMIC_RESTORESTATE)
+ {
+ Buffer->Count++;
+ }
+ }
+
+ /** Removes an element from the ring buffer.
+ *
+ * \note Only one execution thread (main program thread or an ISR) may remove from a single buffer
+ * otherwise data corruption may occur. Insertion and removal may occur from different execution
+ * threads.
+ *
+ * \param[in,out] Buffer Pointer to a ring buffer structure to retrieve from
+ *
+ * \return Next data element stored in the buffer
+ */
+ static inline uint8_t RingBuffer_Remove(RingBuff_t* const Buffer)
+ {
+ uint8_t Data = *Buffer->Out;
+
+ if (++Buffer->Out == Buffer->End)
+ Buffer->Out = Buffer->Start;
+
+ ATOMIC_BLOCK(ATOMIC_RESTORESTATE)
+ {
+ Buffer->Count--;
+ }
+
+ return Data;
+ }
+
+ /** Returns the next element stored in the ring buffer, without removing it.
+ *
+ * \param[in,out] Buffer Pointer to a ring buffer structure to retrieve from
+ *
+ * \return Next data element stored in the buffer
+ */
+ static inline uint8_t RingBuffer_Peek(RingBuff_t* const Buffer)
+ {
+ return *Buffer->Out;
+ }
+
+#endif
+
+/** @} */
+
diff --git a/LUFA/ManPages/ChangeLog.txt b/LUFA/ManPages/ChangeLog.txt index 496bd8d43..382e0ed4d 100644 --- a/LUFA/ManPages/ChangeLog.txt +++ b/LUFA/ManPages/ChangeLog.txt @@ -12,6 +12,8 @@ * - Added new MIDIToneGenerator project * - Added new ORDERED_EP_CONFIG compile time option to restrict endpoint/pipe configuration to ascending order * in exchange for a smaller compiled program binary size + * - Added a new general RingBuff.h miscellaneous ring buffer library driver header + * - Added new GCC_FORCE_POINTER_ACCESS() macro to correct GCC's mishandling of struct pointer accesses * - Library Applications: * - Added new incomplete MIDIToneGenerator project * - Added ability to write protect Mass Storage disk write operations from the host OS @@ -27,6 +29,7 @@ * via the Input Capture register, to reduce user confusion * - Combined page and word ISP programming mode code in the AVRISP-MKII clone project to reduce compiled size and * increase maintainability of the code + * - Changed over library projects to use the new general ring buffer library driver module * * <b>Fixed:</b> * - Core: diff --git a/LUFA/ManPages/FutureChanges.txt b/LUFA/ManPages/FutureChanges.txt index 2197cb5d3..319c4c991 100644 --- a/LUFA/ManPages/FutureChanges.txt +++ b/LUFA/ManPages/FutureChanges.txt @@ -21,7 +21,6 @@ * -# Add HID report macros to make HID report editing easier * -# Investigate dynamically created device descriptors * - Known Bugs - * -# Errors with AVRISP-MKII program with full EEPROM programming on the ATMEGA8 (and others?) * -# No wakeup when plugged into hub, and hub plugged into host * -# Incomplete TMC class demo errors * - Documentation/Support |