msgdma st to MM nios code implementation

[Altera_Forum]

Problems solved- needed some code clean up... 

 // Modular Scatter-Gather DMA ST-to-MM with callback function  # include <stdio.h>  // DMA transfer# include <altera_msgdma_descriptor_regs.h># include <altera_msgdma_csr_regs.h># include <altera_msgdma.h>  // Parallel I/O# include <altera_avalon_pio_regs.h># include <sys/alt_irq.h> # define DMA_LEN_BYTES 1600000 // Size of each DMA transfer in bytes# define BUFFER_A 0x40000000 // SDRAM Buffer A address  // Modular Scatter-Gather DMA Globals alt_msgdma_dev *DATA_DMA_A; alt_msgdma_standard_descriptor DATA_DMA_A_desc;  // DMA variables alt_u32 *DMA_write_addr_ptr_A; // Pointer for DMA A transfer write address alt_u32 DMA_write_addr_A; // DMA A transfer write address  // Declare callback function void DATA_DMA_A_callback_function(void* context);  void DATA_DMA_A_callback_function(void* context) {  alt_msgdma_standard_descriptor_async_transfer(DATA_DMA_A, &DATA_DMA_A_desc);    // Toggle PIO   IOWR_ALTERA_AVALON_PIO_DATA(NIOS_DATA1_READY_BASE, 1);  IOWR_ALTERA_AVALON_PIO_DATA(NIOS_DATA1_READY_BASE, 0); }  int main() {  // Open the streaming modular scatter-gather DMA controllers  DATA_DMA_A = alt_msgdma_open("/dev/data1_msgdma_csr");  if(DATA_DMA_A == NULL)  printf("Could not open the mSG-DMA1\n");   // Configure DMA callback functions  alt_msgdma_register_callback(DATA_DMA_A, DATA_DMA_A_callback_function, 0, NULL);   // Configure the DMA write address  DMA_write_addr_A = (alt_u32) BUFFER_A ;  DMA_write_addr_ptr_A = (alt_u32*)(DMA_write_addr_A);   dma_len_bytes = (alt_u32) DMA_LEN_BYTES;     // Construct the DMA descriptors  alt_msgdma_construct_standard_st_to_mm_descriptor ( DATA_DMA_A,  &DATA_DMA_A_desc, DMA_write_addr_ptr_A, dma_len_bytes,  ALTERA_MSGDMA_DESCRIPTOR_CONTROL_TRANSFER_COMPLETE_IRQ_MASK );   // Start DMA transfers  alt_msgdma_standard_descriptor_async_transfer(DATA_DMA_A, &DATA_DMA_A_desc);   return 0; }