Hi everybody.
I want to transfer data between FPGA and DM3730 using GPMC.
My linux platform driver works fine when I read from and write to FPGA using __reg_read and __reg_write functions.
However, when I want to use DMA over GPMC, I get two different problems:
1- if I use "omap_set_dma_transfer_params(pdata->dma_ch, OMAP_DMA_DATA_TYPE_S16, 0x10, 1, OMAP_DMA_SYNC_FRAME, 0, OMAP_DMA_SRC_SYNC);"
after starting DMA, I will see that data transfer between FPGA and DM3730 takes place,
but I get this error: info: trying to register non-static key and kernel crashes.
2- if I use "omap_set_dma_transfer_params(pdata->dma_ch, OMAP_DMA_DATA_TYPE_S16, 0x10, 1, OMAP_DMA_SYNC_FRAME, OMAP24XX_DMA_GPMC, OMAP_DMA_SRC_SYNC);"
after starting DMA, nothing will happen between FPGA and DM3730 and DMA_callback function will not be called.
I appreciate any help or hint.
Here are important parts of my code:
*************************************************************
if (gpmc_cs_request(gpmc_cfg->cs, SZ_16M, &cs_mem_base) < 0) {
pr_err("Failed to request GPMC mem region\n");
return;
}
gpmc_fpga_resources[0].start = cs_mem_base + 0x0;
gpmc_fpga_resources[0].end = cs_mem_base + 0x10000;
***************************************************************
static int fpga_probe(struct platform_device *p)
{
struct fpga_device_data *pdata = p->dev.platform_data;
res = platform_get_resource_byname(p, IORESOURCE_MEM, "fpga-memory");
request_mem_region(res->start, res_size, FPGA_CHIPNAME);
pdata->phys_base = res->start;
pdata->ioaddr = ioremap(res->start, res_size);
err = omap_request_dma(OMAP24XX_DMA_GPMC, pdata->name, fpga_dma_callback, pdata, &pdata->dma_ch);
return err;
}
****************************************************
static void fpga_dma_callback(int channel_num, u16 ch_status, void *data)
{
struct fpga_device_data *pdata;
pdata = (struct fpga_device_data *)data;
complete(&pdata->dma_complete);
}
*******************************************************
static int fpga_read(struct file *filp, char *buffer, size_t length, loff_t *offset)
{
struct miscdevice *misc;
struct fpga_device_data *pdata;
int size = 2048;
char *DMA_buf = kmalloc(size, GFP_KERNEL | GFP_DMA);
misc = filp->private_data;
pdata = misc->this_device->platform_data;
pdata->dma_phys_addr = dma_map_single(&pdata->dev, DMA_buf, size, DMA_FROM_DEVICE);
if (dma_mapping_error(&pdata->dev, pdata->dma_phys_addr)) {
pr_info("dma_map_single() failed\n");
kfree(DMA_buf);
return -1;
} else {
pr_info("dma_map_single() succeeded: %d", pdata->dma_phys_addr);
}
omap_set_dma_src_params(pdata->dma_ch, 0, OMAP_DMA_AMODE_CONSTANT, pdata->phys_base, 0, 0);
omap_set_dma_dest_params(pdata->dma_ch, 0, OMAP_DMA_AMODE_POST_INC, pdata->dma_phys_addr, 0, 0);
omap_set_dma_transfer_params(pdata->dma_ch, OMAP_DMA_DATA_TYPE_S16, 0x10, 1, OMAP_DMA_SYNC_FRAME, 0, OMAP_DMA_SRC_SYNC);
//omap_set_dma_transfer_params(pdata->dma_ch, OMAP_DMA_DATA_TYPE_S16, 0x10, 1, OMAP_DMA_SYNC_FRAME, OMAP24XX_DMA_GPMC, OMAP_DMA_SRC_SYNC);
//wait for interrupt line from FPGA
wait_event_interruptible(fpga_queue, fpga_flag != 0);
init_completion(&pdata->dma_complete);
omap_start_dma(pdata->dma_ch);
wait_for_completion(&pdata->dma_complete);
dma_unmap_single(&pdata->dev, pdata->dma_phys_addr, size, DMA_FROM_DEVICE);
kfree(DMA_buf);
fpga_flag =0;
return 0;
}
