IMX6Q DMA读写EIM

z358915781

eim_base_addr = ioremap_nocache(0x08000000, SDMA_BUF_SIZE);
*(eim_base_addr )=0xAA55。直接写EIM总线能正常正常些EIM总线，但DAM去操作却毫无反应
//关键实现代码如下：
dma_m2m_config.direction = DMA_MEM_TO_MEM;
dma_m2m_config.dst_addr_width = DMA_SLAVE_BUSWIDTH_2_BYTES;
dmaengine_slave_config(dma_m2m_chan, &dma_m2m_config);

sg_init_table(sg, 1);  
sg_set_buf(&sg[0], eim_base_addr, SDMA_BUF_SIZE);  
ret = dma_map_sg(NULL, sg, DEF_SG_QTY, dma_m2m_config.direction);
dma_m2m_desc = dma_m2m_chan->device->device_prep_slave_sg(dma_m2m_chan, sg, DEF_SG_QTY, dma_m2m_config.direction, 1);
sg_init_table(sg2, 1)；
sg_set_buf(&sg2[0], rbuf, SDMA_BUF_SIZE);
ret = dma_map_sg(NULL, sg2, DEF_SG_QTY, dma_m2m_config.direction);
dma_m2m_desc = dma_m2m_chan->device->device_prep_slave_sg(dma_m2m_chan,sg2, DEF_SG_QTY, dma_m2m_config.direction, 0);

dma_m2m_desc->callback = dma_m2m_callback;
dmaengine_submit(dma_m2m_desc); dma_async_issue_pending(dma_m2m_chan);
执行DMA后却毫无反应？？？？？求正解？？？

我知道答案 目前已有1人回答

阅读全文

z358915781

DEF_SG_QTY定义的是1  SDMA_BUF_SIZE 1024*32