Introduction

SimpleDMA is a standard library for different DMA peripherals. Currently the LPC1768, KL46Z and KL25Z are supported. It provided one set of functions for different peripherals. It does not allow for usage of all the advanced functions, partially because the goal was to provide a simple interface, and partially because they are different for different microcontrollers.

Examples

Helloworld: http://mbed.org/users/Sissors/code/SimpleDMA_HelloWorld/

Example in a library (SPI): http://mbed.org/users/Sissors/code/RTOS_SPI/

SimpleDMA.h@5:d9f46ef80e20, 2014-01-04 (annotated)

Committer:: Sissors
Date:: Sat Jan 04 14:42:33 2014 +0000
Revision:: 5:d9f46ef80e20
Parent:: 4:c3a84c6c432c
Child:: 7:d3be727fa9d2

Refactored code, added LPC1768 support

Who changed what in which revision?

User	Revision	Line number	New contents of line
Sissors	0:d77ea45fa625	1	#ifndef SIMPLEDMA_H
Sissors	0:d77ea45fa625	2	#define SIMPLEDMA_H
Sissors	0:d77ea45fa625	3
Sissors	2:fe2fcaa72434	4	#ifdef RTOS_H
Sissors	2:fe2fcaa72434	5	#include "rtos.h"
Sissors	2:fe2fcaa72434	6	#endif
Sissors	2:fe2fcaa72434	7
Sissors	0:d77ea45fa625	8	#include "mbed.h"
Sissors	0:d77ea45fa625	9	#include "SimpleDMA_KL25.h"
Sissors	5:d9f46ef80e20	10	#include "SimpleDMA_LPC1768.h"
Sissors	0:d77ea45fa625	11
Sissors	0:d77ea45fa625	12
Sissors	0:d77ea45fa625	13	/**
Sissors	0:d77ea45fa625	14	* SimpleDMA, DMA made simple! (Okay that was bad)
Sissors	0:d77ea45fa625	15	*
Sissors	0:d77ea45fa625	16	* A class to easily make basic DMA operations happen. Not all features
Sissors	0:d77ea45fa625	17	* of the DMA peripherals are used, but the main ones are: From and to memory
Sissors	0:d77ea45fa625	18	* and peripherals, either continiously or triggered
Sissors	0:d77ea45fa625	19	*/
Sissors	0:d77ea45fa625	20	class SimpleDMA {
Sissors	0:d77ea45fa625	21	public:
Sissors	3:34f5bf8adfa0	22	/**
Sissors	3:34f5bf8adfa0	23	* Constructor
Sissors	3:34f5bf8adfa0	24	*
Sissors	3:34f5bf8adfa0	25	* @param channel - optional parameter which channel should be used, default is automatic channel selection
Sissors	3:34f5bf8adfa0	26	*/
Sissors	3:34f5bf8adfa0	27	SimpleDMA(int channel = -1);
Sissors	0:d77ea45fa625	28
Sissors	0:d77ea45fa625	29	/**
Sissors	0:d77ea45fa625	30	* Set the source of the DMA transfer
Sissors	0:d77ea45fa625	31	*
Sissors	0:d77ea45fa625	32	* Autoincrement increments the pointer after each transfer. If the source
Sissors	0:d77ea45fa625	33	* is an array this should be true, if it is a peripheral or a single memory
Sissors	0:d77ea45fa625	34	* location it should be false.
Sissors	0:d77ea45fa625	35	*
Sissors	0:d77ea45fa625	36	* The source can be any pointer to any memory location. Automatically
Sissors	0:d77ea45fa625	37	* the wordsize is calculated depending on the type, if required you can
Sissors	0:d77ea45fa625	38	* also override this.
Sissors	0:d77ea45fa625	39	*
Sissors	0:d77ea45fa625	40	* @param pointer - pointer to the memory location
Sissors	0:d77ea45fa625	41	* @param autoinc - should the pointer be incremented by the DMA module
Sissors	3:34f5bf8adfa0	42	* @param size - wordsize in bits (optional, generally can be omitted)
Sissors	0:d77ea45fa625	43	* @return - 0 on success
Sissors	0:d77ea45fa625	44	*/
Sissors	0:d77ea45fa625	45	template<typename Type>
Sissors	5:d9f46ef80e20	46	void source(Type* pointer, bool autoinc, int size = sizeof(Type) * 8) {
Sissors	5:d9f46ef80e20	47	_source = (uint32_t)pointer;
Sissors	5:d9f46ef80e20	48	source_inc = autoinc;
Sissors	5:d9f46ef80e20	49	source_size = size;
Sissors	0:d77ea45fa625	50	}
Sissors	0:d77ea45fa625	51
Sissors	0:d77ea45fa625	52	/**
Sissors	0:d77ea45fa625	53	* Set the destination of the DMA transfer
Sissors	0:d77ea45fa625	54	*
Sissors	0:d77ea45fa625	55	* Autoincrement increments the pointer after each transfer. If the source
Sissors	0:d77ea45fa625	56	* is an array this should be true, if it is a peripheral or a single memory
Sissors	0:d77ea45fa625	57	* location it should be false.
Sissors	0:d77ea45fa625	58	*
Sissors	0:d77ea45fa625	59	* The destination can be any pointer to any memory location. Automatically
Sissors	0:d77ea45fa625	60	* the wordsize is calculated depending on the type, if required you can
Sissors	0:d77ea45fa625	61	* also override this.
Sissors	0:d77ea45fa625	62	*
Sissors	0:d77ea45fa625	63	* @param pointer - pointer to the memory location
Sissors	0:d77ea45fa625	64	* @param autoinc - should the pointer be incremented by the DMA module
Sissors	3:34f5bf8adfa0	65	* @param size - wordsize in bits (optional, generally can be omitted)
Sissors	0:d77ea45fa625	66	* @return - 0 on success
Sissors	0:d77ea45fa625	67	*/
Sissors	0:d77ea45fa625	68	template<typename Type>
Sissors	5:d9f46ef80e20	69	void destination(Type* pointer, bool autoinc, int size = sizeof(Type) * 8) {
Sissors	5:d9f46ef80e20	70	_destination = (uint32_t)pointer;
Sissors	5:d9f46ef80e20	71	destination_inc = autoinc;
Sissors	5:d9f46ef80e20	72	destination_size = size;
Sissors	0:d77ea45fa625	73	}
Sissors	0:d77ea45fa625	74
Sissors	0:d77ea45fa625	75	/**
Sissors	0:d77ea45fa625	76	* Set the trigger for the DMA operation
Sissors	0:d77ea45fa625	77	*
Sissors	0:d77ea45fa625	78	* In SimpleDMA_[yourdevice].h you can find the names of the different triggers.
Sissors	0:d77ea45fa625	79	* Trigger_ALWAYS is defined for all devices, it will simply move the data
Sissors	0:d77ea45fa625	80	* as fast as possible. Used for memory-memory transfers. If nothing else is set
Sissors	0:d77ea45fa625	81	* that will be used by default.
Sissors	0:d77ea45fa625	82	*
Sissors	0:d77ea45fa625	83	* @param trig - trigger to use
Sissors	0:d77ea45fa625	84	* @param return - 0 on success
Sissors	0:d77ea45fa625	85	*/
Sissors	5:d9f46ef80e20	86	void trigger(SimpleDMA_Trigger trig) {
Sissors	5:d9f46ef80e20	87	_trigger = trig;
Sissors	5:d9f46ef80e20	88	}
Sissors	0:d77ea45fa625	89
Sissors	0:d77ea45fa625	90	/**
Sissors	3:34f5bf8adfa0	91	* Set the DMA channel
Sissors	3:34f5bf8adfa0	92	*
Sissors	3:34f5bf8adfa0	93	* Generally you will not need to call this function, the constructor does so for you
Sissors	3:34f5bf8adfa0	94	*
Sissors	3:34f5bf8adfa0	95	* @param chan - DMA channel to use, -1 = variable channel (highest priority channel which is available)
Sissors	3:34f5bf8adfa0	96	*/
Sissors	3:34f5bf8adfa0	97	void channel(int chan);
Sissors	3:34f5bf8adfa0	98
Sissors	3:34f5bf8adfa0	99	/**
Sissors	0:d77ea45fa625	100	* Start the transfer
Sissors	0:d77ea45fa625	101	*
Sissors	0:d77ea45fa625	102	* @param length - number of BYTES to be moved by the DMA
Sissors	0:d77ea45fa625	103	*/
Sissors	0:d77ea45fa625	104	int start(int length);
Sissors	0:d77ea45fa625	105
Sissors	0:d77ea45fa625	106	/**
Sissors	0:d77ea45fa625	107	* Is the DMA channel busy
Sissors	0:d77ea45fa625	108	*
Sissors	3:34f5bf8adfa0	109	* @param channel - channel to check, -1 = current channel
Sissors	0:d77ea45fa625	110	* @return - true if it is busy
Sissors	0:d77ea45fa625	111	*/
Sissors	3:34f5bf8adfa0	112	bool isBusy( int channel = -1 );
Sissors	0:d77ea45fa625	113
Sissors	1:0b73b00bcee8	114	/**
Sissors	1:0b73b00bcee8	115	* Attach an interrupt upon completion of DMA transfer or error
Sissors	1:0b73b00bcee8	116	*
Sissors	1:0b73b00bcee8	117	* @param function - function to call upon completion (may be a member function)
Sissors	1:0b73b00bcee8	118	*/
Sissors	1:0b73b00bcee8	119	void attach(void (*function)(void)) {
Sissors	1:0b73b00bcee8	120	_callback.attach(function);
Sissors	1:0b73b00bcee8	121	}
Sissors	1:0b73b00bcee8	122
Sissors	1:0b73b00bcee8	123	template<typename T>
Sissors	1:0b73b00bcee8	124	void attach(T object, void (T::member)(void)) {
Sissors	1:0b73b00bcee8	125	_callback.attach(object, member);
Sissors	1:0b73b00bcee8	126	}
Sissors	0:d77ea45fa625	127
Sissors	2:fe2fcaa72434	128	#ifdef RTOS_H
Sissors	3:34f5bf8adfa0	129	/**
Sissors	3:34f5bf8adfa0	130	* Start a DMA transfer similar to start, however block current Thread
Sissors	3:34f5bf8adfa0	131	* until the transfer is finished
Sissors	3:34f5bf8adfa0	132	*
Sissors	3:34f5bf8adfa0	133	* When using this function only the current Thread is halted.
Sissors	3:34f5bf8adfa0	134	* The Thread is moved to Waiting state: other Threads will continue
Sissors	3:34f5bf8adfa0	135	* to run normally.
Sissors	3:34f5bf8adfa0	136	*
Sissors	3:34f5bf8adfa0	137	* This function is only available if you included rtos.h before
Sissors	3:34f5bf8adfa0	138	* including SimpleDMA.h.
Sissors	3:34f5bf8adfa0	139	*
Sissors	3:34f5bf8adfa0	140	* @param length - number of BYTES to be moved by the DMA
Sissors	3:34f5bf8adfa0	141	*/
Sissors	2:fe2fcaa72434	142	void wait(int length) {
Sissors	1:0b73b00bcee8	143	id = Thread::gettid();
Sissors	1:0b73b00bcee8	144	this->attach(this, &SimpleDMA::waitCallback);
Sissors	2:fe2fcaa72434	145	this->start(length);
Sissors	1:0b73b00bcee8	146	Thread::signal_wait(0x1);
Sissors	1:0b73b00bcee8	147	}
Sissors	2:fe2fcaa72434	148	#endif
Sissors	0:d77ea45fa625	149
Sissors	0:d77ea45fa625	150	protected:
Sissors	5:d9f46ef80e20	151	int _channel;
Sissors	5:d9f46ef80e20	152	SimpleDMA_Trigger _trigger;
Sissors	5:d9f46ef80e20	153	uint32_t _source;
Sissors	5:d9f46ef80e20	154	uint32_t _destination;
Sissors	5:d9f46ef80e20	155	bool source_inc;
Sissors	5:d9f46ef80e20	156	bool destination_inc;
Sissors	5:d9f46ef80e20	157	uint8_t source_size;
Sissors	5:d9f46ef80e20	158	uint8_t destination_size;
Sissors	1:0b73b00bcee8	159
Sissors	3:34f5bf8adfa0	160	bool auto_channel;
Sissors	2:fe2fcaa72434	161
Sissors	2:fe2fcaa72434	162	//IRQ handlers
Sissors	1:0b73b00bcee8	163	FunctionPointer _callback;
Sissors	1:0b73b00bcee8	164	void irq_handler(void);
Sissors	0:d77ea45fa625	165
Sissors	5:d9f46ef80e20	166	static SimpleDMA *irq_owner[DMA_CHANNELS];
Sissors	5:d9f46ef80e20	167
Sissors	5:d9f46ef80e20	168	static void irq_handler0( void );
Sissors	1:0b73b00bcee8	169
Sissors	5:d9f46ef80e20	170	#if DMA_IRQS > 1
Sissors	5:d9f46ef80e20	171	static void irq_handler1( void );
Sissors	5:d9f46ef80e20	172	static void irq_handler2( void );
Sissors	5:d9f46ef80e20	173	static void irq_handler3( void );
Sissors	5:d9f46ef80e20	174	#endif
Sissors	2:fe2fcaa72434	175
Sissors	5:d9f46ef80e20	176	//Keep searching until we find a non-busy channel, start with lowest channel number
Sissors	5:d9f46ef80e20	177	int getFreeChannel(void);
Sissors	2:fe2fcaa72434	178
Sissors	2:fe2fcaa72434	179	#ifdef RTOS_H
Sissors	1:0b73b00bcee8	180	osThreadId id;
Sissors	1:0b73b00bcee8	181	void waitCallback(void) {
Sissors	2:fe2fcaa72434	182	osSignalSet(id, 0x1);
Sissors	1:0b73b00bcee8	183	}
Sissors	2:fe2fcaa72434	184	#endif
Sissors	0:d77ea45fa625	185	};
Sissors	0:d77ea45fa625	186	#endif