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@2:fe2fcaa72434, 2013-12-22 (annotated)

Committer:: Sissors
Date:: Sun Dec 22 21:42:49 2013 +0000
Revision:: 2:fe2fcaa72434
Parent:: 1:0b73b00bcee8
Child:: 3:34f5bf8adfa0

v1.0 KL25Z

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	0:d77ea45fa625	10
Sissors	0:d77ea45fa625	11
Sissors	0:d77ea45fa625	12	/**
Sissors	0:d77ea45fa625	13	* SimpleDMA, DMA made simple! (Okay that was bad)
Sissors	0:d77ea45fa625	14	*
Sissors	0:d77ea45fa625	15	* A class to easily make basic DMA operations happen. Not all features
Sissors	0:d77ea45fa625	16	* of the DMA peripherals are used, but the main ones are: From and to memory
Sissors	0:d77ea45fa625	17	* and peripherals, either continiously or triggered
Sissors	0:d77ea45fa625	18	*/
Sissors	0:d77ea45fa625	19	class SimpleDMA {
Sissors	0:d77ea45fa625	20	public:
Sissors	0:d77ea45fa625	21	SimpleDMA(int channel = 0);
Sissors	0:d77ea45fa625	22
Sissors	0:d77ea45fa625	23	/**
Sissors	0:d77ea45fa625	24	* Set the source of the DMA transfer
Sissors	0:d77ea45fa625	25	*
Sissors	0:d77ea45fa625	26	* Autoincrement increments the pointer after each transfer. If the source
Sissors	0:d77ea45fa625	27	* is an array this should be true, if it is a peripheral or a single memory
Sissors	0:d77ea45fa625	28	* location it should be false.
Sissors	0:d77ea45fa625	29	*
Sissors	0:d77ea45fa625	30	* The source can be any pointer to any memory location. Automatically
Sissors	0:d77ea45fa625	31	* the wordsize is calculated depending on the type, if required you can
Sissors	0:d77ea45fa625	32	* also override this.
Sissors	0:d77ea45fa625	33	*
Sissors	0:d77ea45fa625	34	* @param pointer - pointer to the memory location
Sissors	0:d77ea45fa625	35	* @param autoinc - should the pointer be incremented by the DMA module
Sissors	0:d77ea45fa625	36	* @param size - size of the transfer (optional, generally can be omitted)
Sissors	0:d77ea45fa625	37	* @return - 0 on success
Sissors	0:d77ea45fa625	38	*/
Sissors	0:d77ea45fa625	39	template<typename Type>
Sissors	0:d77ea45fa625	40	int source(Type* pointer, bool autoinc, int size = sizeof(Type*)) {
Sissors	2:fe2fcaa72434	41	return setAddress((uint32_t)pointer, size, true, autoinc);
Sissors	0:d77ea45fa625	42	}
Sissors	0:d77ea45fa625	43
Sissors	0:d77ea45fa625	44	/**
Sissors	0:d77ea45fa625	45	* Set the destination of the DMA transfer
Sissors	0:d77ea45fa625	46	*
Sissors	0:d77ea45fa625	47	* Autoincrement increments the pointer after each transfer. If the source
Sissors	0:d77ea45fa625	48	* is an array this should be true, if it is a peripheral or a single memory
Sissors	0:d77ea45fa625	49	* location it should be false.
Sissors	0:d77ea45fa625	50	*
Sissors	0:d77ea45fa625	51	* The destination can be any pointer to any memory location. Automatically
Sissors	0:d77ea45fa625	52	* the wordsize is calculated depending on the type, if required you can
Sissors	0:d77ea45fa625	53	* also override this.
Sissors	0:d77ea45fa625	54	*
Sissors	0:d77ea45fa625	55	* @param pointer - pointer to the memory location
Sissors	0:d77ea45fa625	56	* @param autoinc - should the pointer be incremented by the DMA module
Sissors	0:d77ea45fa625	57	* @param size - size of the transfer (optional, generally can be omitted)
Sissors	0:d77ea45fa625	58	* @return - 0 on success
Sissors	0:d77ea45fa625	59	*/
Sissors	0:d77ea45fa625	60	template<typename Type>
Sissors	0:d77ea45fa625	61	int destination(Type* pointer, bool autoinc, int size = sizeof(Type*)) {
Sissors	2:fe2fcaa72434	62	return setAddress((uint32_t)pointer, size, false, autoinc);
Sissors	0:d77ea45fa625	63	}
Sissors	0:d77ea45fa625	64
Sissors	0:d77ea45fa625	65	/**
Sissors	0:d77ea45fa625	66	* Set the trigger for the DMA operation
Sissors	0:d77ea45fa625	67	*
Sissors	0:d77ea45fa625	68	* In SimpleDMA_[yourdevice].h you can find the names of the different triggers.
Sissors	0:d77ea45fa625	69	* Trigger_ALWAYS is defined for all devices, it will simply move the data
Sissors	0:d77ea45fa625	70	* as fast as possible. Used for memory-memory transfers. If nothing else is set
Sissors	0:d77ea45fa625	71	* that will be used by default.
Sissors	0:d77ea45fa625	72	*
Sissors	0:d77ea45fa625	73	* @param trig - trigger to use
Sissors	0:d77ea45fa625	74	* @param return - 0 on success
Sissors	0:d77ea45fa625	75	*/
Sissors	0:d77ea45fa625	76	int trigger(SimpleDMA_Trigger trig);
Sissors	0:d77ea45fa625	77
Sissors	0:d77ea45fa625	78	/**
Sissors	0:d77ea45fa625	79	* Start the transfer
Sissors	0:d77ea45fa625	80	*
Sissors	0:d77ea45fa625	81	* @param length - number of BYTES to be moved by the DMA
Sissors	0:d77ea45fa625	82	*/
Sissors	0:d77ea45fa625	83	int start(int length);
Sissors	0:d77ea45fa625	84
Sissors	0:d77ea45fa625	85	/**
Sissors	0:d77ea45fa625	86	* Is the DMA channel busy
Sissors	0:d77ea45fa625	87	*
Sissors	0:d77ea45fa625	88	* @return - true if it is busy
Sissors	0:d77ea45fa625	89	*/
Sissors	0:d77ea45fa625	90	bool isBusy( void );
Sissors	0:d77ea45fa625	91
Sissors	1:0b73b00bcee8	92	/**
Sissors	1:0b73b00bcee8	93	* Attach an interrupt upon completion of DMA transfer or error
Sissors	1:0b73b00bcee8	94	*
Sissors	1:0b73b00bcee8	95	* @param function - function to call upon completion (may be a member function)
Sissors	1:0b73b00bcee8	96	*/
Sissors	1:0b73b00bcee8	97	void attach(void (*function)(void)) {
Sissors	1:0b73b00bcee8	98	irq_en = function;
Sissors	1:0b73b00bcee8	99	_callback.attach(function);
Sissors	1:0b73b00bcee8	100	}
Sissors	1:0b73b00bcee8	101
Sissors	1:0b73b00bcee8	102	template<typename T>
Sissors	1:0b73b00bcee8	103	void attach(T object, void (T::member)(void)) {
Sissors	1:0b73b00bcee8	104	irq_en = object;
Sissors	1:0b73b00bcee8	105	_callback.attach(object, member);
Sissors	1:0b73b00bcee8	106	}
Sissors	0:d77ea45fa625	107
Sissors	2:fe2fcaa72434	108	#ifdef RTOS_H
Sissors	2:fe2fcaa72434	109	void wait(int length) {
Sissors	1:0b73b00bcee8	110	id = Thread::gettid();
Sissors	1:0b73b00bcee8	111	this->attach(this, &SimpleDMA::waitCallback);
Sissors	2:fe2fcaa72434	112	this->start(length);
Sissors	1:0b73b00bcee8	113	Thread::signal_wait(0x1);
Sissors	1:0b73b00bcee8	114	}
Sissors	2:fe2fcaa72434	115	#endif
Sissors	0:d77ea45fa625	116
Sissors	0:d77ea45fa625	117	protected:
Sissors	1:0b73b00bcee8	118	/**
Sissors	1:0b73b00bcee8	119	* Set the DMA channel
Sissors	1:0b73b00bcee8	120	*
Sissors	1:0b73b00bcee8	121	* @param chan - DMA channel to use
Sissors	1:0b73b00bcee8	122	*/
Sissors	1:0b73b00bcee8	123	void channel(int chan);
Sissors	2:fe2fcaa72434	124	int setAddress(uint32_t address, int wordsize, bool source, bool autoinc);
Sissors	1:0b73b00bcee8	125
Sissors	0:d77ea45fa625	126	int _channel;
Sissors	2:fe2fcaa72434	127	uint32_t SAR, DAR, DSR, DCR;
Sissors	2:fe2fcaa72434	128	uint8_t CHCFG;
Sissors	2:fe2fcaa72434	129
Sissors	2:fe2fcaa72434	130	//IRQ handlers
Sissors	1:0b73b00bcee8	131	FunctionPointer _callback;
Sissors	1:0b73b00bcee8	132	bool irq_en;
Sissors	1:0b73b00bcee8	133	void irq_handler(void);
Sissors	0:d77ea45fa625	134
Sissors	1:0b73b00bcee8	135	static SimpleDMA *irq_owner[4];
Sissors	1:0b73b00bcee8	136
Sissors	1:0b73b00bcee8	137	static void irq_handler0( void ) {
Sissors	1:0b73b00bcee8	138	if (irq_owner[0]!=NULL)
Sissors	1:0b73b00bcee8	139	irq_owner[0]->irq_handler();
Sissors	1:0b73b00bcee8	140	}
Sissors	1:0b73b00bcee8	141	static void irq_handler1( void ) {
Sissors	1:0b73b00bcee8	142	if (irq_owner[1]!=NULL)
Sissors	1:0b73b00bcee8	143	irq_owner[1]->irq_handler();
Sissors	1:0b73b00bcee8	144	}
Sissors	1:0b73b00bcee8	145	static void irq_handler2( void ) {
Sissors	1:0b73b00bcee8	146	if (irq_owner[2]!=NULL)
Sissors	1:0b73b00bcee8	147	irq_owner[2]->irq_handler();
Sissors	1:0b73b00bcee8	148	}
Sissors	1:0b73b00bcee8	149	static void irq_handler3( void ) {
Sissors	1:0b73b00bcee8	150	if (irq_owner[3]!=NULL)
Sissors	1:0b73b00bcee8	151	irq_owner[3]->irq_handler();
Sissors	1:0b73b00bcee8	152	}
Sissors	2:fe2fcaa72434	153
Sissors	2:fe2fcaa72434	154
Sissors	2:fe2fcaa72434	155	#ifdef RTOS_H
Sissors	1:0b73b00bcee8	156	osThreadId id;
Sissors	1:0b73b00bcee8	157	void waitCallback(void) {
Sissors	2:fe2fcaa72434	158	osSignalSet(id, 0x1);
Sissors	1:0b73b00bcee8	159	}
Sissors	2:fe2fcaa72434	160	#endif
Sissors	0:d77ea45fa625	161
Sissors	0:d77ea45fa625	162	};
Sissors	0:d77ea45fa625	163	#endif