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Altera_Forum's avatar
Altera_Forum
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10 years ago

mSGDMA, Qsys, and Linux Integration

So I've been trying to get the Modular SG-DMA working in a Qsys project tied with Linux. I can get it to show up in the device tree, be recognized by Linux in /sys, and it looks like the memory mappi...
Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
10 years ago

I do control mSGDMA with lightweight AXI

In QSys:

CSR, Descriptor, Response connected to lw_axi_master

mm_write connected to f2h_axi_slave

In Linux:

open /dev/mem

mmap to 0xFF200000 with offset of registers addresses 


# pragma pack(push,1)
/**
 * @brief mSGDMA control and status register
 */
typedef struct {
	uint32_t	status;
	uint32_t	control;
	uint16_t	rd_fill_level;
	uint16_t	wr_fill_level;
	uint16_t	resp_fill_level;
	uint16_t	reserved_0;
	uint16_t	rd_sequence_number;
	uint16_t	wr_sequence_number;
	uint32_t	reserved_1;
	uint32_t	reserved_2;
	uint32_t	reserved_3;
} t_mSGDMA_CSR;
# pragma pack(pop)
t_mSGDMA_CSR * regs_CSR;
fd_FPGA_ctrl_regs = open("/dev/mem", O_RDWR|O_SYNC);
mem_FPGA_ctrl_regs = (unsigned int*)mmap(NULL, MAP_PIO_SIZE, PROT_READ|PROT_WRITE, MAP_SHARED, fd_FPGA_ctrl_regs, 0xFF200000);
regs_CSR= (t_mSGDMA_CSR*)(p_mmap_mSGDMA_control + mSGDMA_CSR_offset		/ sizeof(uint32_t));
/* descriptor, response is the same */
/* and registers are ready to use */