case DMA_BUF_SYNC_READ: dir = DMA_FROM_DEVICE; break; case DMA_BUF_SYNC_WRITE: dir = DMA_TO_DEVICE; break; case DMA_BUF_SYNC_RW: dir = DMA_BIDIRECTIONAL; break; default: return (EINVAL); } if (sync->flags & DMA_BUF_SYNC_END) ...
dmabuf=ioremap(0XFF00000/**255M/, 0X100000/*1M/*);解决方法之二是使用GPF_NOFAIL分配标志为缓冲...
if (read_card_status(cp) == RX_BUF_TRANSFERRED) { struct my_card_header *hp; HW已经完成了传输,在cpu访问buffer之前,cpu需要先sync一下,以便看到最新的数据。 dma_sync_single_for_cpu(&cp->dev, cp->rx_dma, cp->rx_len, DMA_FROM_DEVICE); sync之后就可以安全的读dma buffer了 hp = (struc...
int ddi_dma_buf_bind_handle(ddi_dma_handle_t handle, struct buf *bp, uint_t flags, int (*callback)(caddr_t), caddr_t arg, ddi_dma_cookie_t *cookiep, uint_t *ccountp);INTERFACE LEVELSolaris DDI specific (Solaris DDI).PARAMETERS...
...if(read_card_status(cp) == RX_BUF_TRANSFERRED) {structmy_card_header*hp; HW已经完成了传输,在cpu访问buffer之前,cpu需要先sync一下,以便看到最新的数据。dma_sync_single_for_cpu(&cp->dev, cp->rx_dma, cp->rx_len, DMA_FROM_DEVICE); ...
sync_file.h> #include <linux/poll.h> #include <linux/dma-resv.h> #include <linux/mm.h> #include <linux/mount.h> #include <linux/pseudo_fs.h> #include #include #include "dma-buf-sysfs-stats.h" static inline int is_dma_buf_file(struct file *); #if IS_ENABLED(CONFIG_DEBUG_...
45 size_t ret = 0; 46 47 dmabuf = dentry->d_fsdata; 48 spin_lock(&dmabuf->name_lock); 49 if (dmabuf->name) 50 ret = strlcpy(name, dmabuf->name, DMA_BUF_NAME_LEN); 51 spin_unlock(&dmabuf->name_lock); 52 53 return dynamic_dname(dentry, buffer, buflen, "/%s:%s", 54...
* DMA_BUF_SYNC_READ: * Indicates that the mapped DMA buffer will be read by the * client via the CPU map. * * DMA_BUF_SYNC_WRITE: * Indicates that the mapped DMA buffer will be written by the * client via the CPU map.
接口驱动属于字符设备驱动.重点在初始化和read函数部分。 初始化函数中完成DMA引脚定义、BANK4总线设置、申请DMA通道以及注册字符设备等。read函数是接口驱动的核心。应用程序正是通过调用read函数来读取数据。其核心代码如下: fpga_buf_t *b=&fpga_buf; dma_addr_t *buf; b->size=count; buf=kmalloc(b->size...
在调用一次DMA_start(dmaHandle)之后,产生了一次中断,完成I2S_DMA_BUF_LEN*2字节的数据dmaSrcBuf到dmaDstBuf的传输。 由于设置了dmaConfig.autoMode = CSL_DMA_AUTORELOAD_ENABLE,DMA会继续自动完成传输。 所以,当更新dmaSrcBuf中的数据时,dmaDstBuf也会被更新。