写在前面的话:
本篇是AXI DMA在linux下使用的例子。
包括PL端设计,基于vivado 2015.4,petalinux 2016.1,基于linux 4.4内核。
我在git hub 上托管了代码,https://github.com/shichaog/zynq-dma,如果想加入github上这个项目,给我邮箱发信息shichaog@126.com,方便为你配权限。
1.PL端设计:
PL端设计包括四个AXI DMA IP,它们分别和zynq处理IP的HP口相连接。
这个设计是基于Avnet-Digilent-ZedBoard-v2016.1-final.bsp,由于其它的ip都是xilinx开发环境开发环境就有,所以这里就不详细每一步设计过程了。
这些IP包括AXI interconnect, system reset,axi dma,concat。
注意concat是用来将AXI DMA的中断传递给zynq之用的,这是必须有的,否则在hdf导入时,会出现如下错误:
2 接下来是创建module和app了
这两个命令执行后,会分配在components/apps和components/modules目录下生成dmaBench和ds_axidma两个文件夹,该文件下的两个文件内容使用如下的文件替换。
《dmaBench.c》
#include <stdio.h>
#include <fcntl.h>
#include <string.h>
#include <stdlib.h>
#include <sys/time.h>
unsigned long tStart, tEnd;
unsigned long data;
unsigned long getTime(){
struct timeval temp;
gettimeofday(&temp, NULL);
return temp.tv_sec * 1000 * 1000 + temp.tv_usec;
}
void report(char *msg, unsigned long data, unsigned long time, unsigned long dmaUsed){
printf("%s\t%ld\t%ld\t%f\t%d\n", msg, data, time, data * 1.0 / time, dmaUsed);
FILE *f = fopen("report.dat", "a");
fprintf(f, "%s\t%ld\t%ld\t%f\t%d\n", msg, data, time, data * 1.0 / time, dmaUsed);
fclose(f);
}
#define REPORT(f, timeStart, timeEnd, dataPtr, msg, dmaUsed) *timeStart = getTime(); *dataPtr = f; *timeEnd = getTime(); report(msg, *dataPtr, *timeEnd - *timeStart, dmaUsed);
void checkData(char *bufferIn, char *bufferOut, unsigned int elems){
int i;
if(!memcmp(bufferIn, bufferOut, elems*sizeof(char))){
printf("DMA Ok!\n");
}
else{
for(i=0;i<elems;i++)
printf("%d\t%d\t%d\t%d\n", i, bufferIn[i], bufferOut[i], (i==0 ? 0 : bufferOut[i] - bufferOut[i-1]));
}
}
unsigned long memCpy_ARM(char *bufferIn, char *bufferOut, unsigned long elems, size_t size){
int i;
for(i=0; i<elems; i++)
bufferOut[i] = bufferIn[i];
return elems * size;
}
unsigned long memCpy_DMA(char *bufferIn, char *bufferOut, unsigned long elems, size_t size, int dmaToUse){
#define FIFO_LEN 4000
#define DMA_NUM 4
int fd[DMA_NUM];
fd[0] = open("/dev/axi_dma_0", O_RDWR);
fd[1] = open("/dev/axi_dma_1", O_RDWR);
fd[2] = open("/dev/axi_dma_2", O_RDWR);
fd[3] = open("/dev/axi_dma_3", O_RDWR);
unsigned long byteMoved = 0;
unsigned long byteToMove = 0;
int i;
while(byteMoved!=size * elems){
byteToMove = size * elems - byteMoved > FIFO_LEN ? FIFO_LEN : size * elems - byteMoved;
for(i=0; i<dmaToUse; i++){
write(fd[i], &bufferIn[byteMoved], byteToMove);
}
for(i=0; i<dmaToUse; i++)
read(fd[i], &bufferOut[byteMoved], byteToMove);
byteMoved += byteToMove;
}
close(fd[0]);
close(fd[1]);
close(fd[2]);
close(fd[3]);
return elems * size * dmaToUse;
}
int main(int argc, char **argv)
{
char *bufferIn, *bufferOut_ARM, *bufferOut_DMA;
if(argc!=3){
printf("Usage: ./dmaBench DATA DMA_TO_USE\n");
exit(0);
}
unsigned long DATA = atoi(argv[1]);
unsigned int DMA_TO_USE = atoi(argv[2]);
bufferIn = (char *) malloc(sizeof(char) * DATA);
bufferOut_ARM = (char *) malloc(sizeof(char) * DATA);
bufferOut_DMA = (char *) malloc(sizeof(char) * DATA);
int i;
for(i=0; i<DATA; i++){
bufferIn[i] = i;
}
memset(bufferOut_ARM, 0, sizeof(char) * DATA);
memset(bufferOut_DMA, 0, sizeof(char) * DATA);
REPORT(memCpy_ARM(bufferIn, bufferOut_ARM, DATA, sizeof(char)), &tStart, &tEnd, &data, "ARM", 0);
for(i=0; i<DMA_TO_USE; i++){
REPORT(memCpy_DMA(bufferIn, bufferOut_DMA, DATA/(i+1), sizeof(char), (i+1)), &tStart, &tEnd, &data, "DMA", (i+1));
}
checkData(bufferIn, bufferOut_ARM, DATA);
checkData(bufferIn, bufferOut_DMA, DATA);
return 0;
}
和<ds_axidma>
/*
* Xilinx AXI DMA Driver
*
* Authors:
* Fabrizio Spada - fabrizio.spada@mail.polimi.it
* Gianluca Durelli - durelli@elet.polimi.it
* Politecnico di Milano
*
* This is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*/
#include <linux/module.h>
#include <linux/version.h>
#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/kdev_t.h>
#include <linux/fs.h>
#include <linux/list.h>
#include <linux/device.h>
#include <linux/cdev.h>
#include <linux/dma-mapping.h>
#include <linux/pm_runtime.h>
#include <linux/slab.h>
#include <linux/of.h>
#include <linux/of_platform.h>
#include <linux/of_address.h>
#include <linux/mm.h>
#include <asm/io.h>
#define MM2S_DMACR 0x00
#define MM2S_DMASR 0x04
#define MM2S_SA 0x18
#define MM2S_LENGTH 0x28
#define S2MM_DMACR 0x30
#define S2MM_DMASR 0x34
#define S2MM_DA 0x48
#define S2MM_LENGTH 0x58
#define DRIVER_NAME "ds_axidma_pdrv"
#define MODULE_NAME "ds_axidma"
#define DMA_LENGTH (32*1024)
static struct class *cl; // Global variable for the device class
struct ds_axidma_device
{
phys_addr_t bus_addr;
unsigned long bus_size;
char *virt_bus_addr;
dev_t dev_num;
const char *dev_name;
struct cdev c_dev;
char *ds_axidma_addr;
dma_addr_t ds_axidma_handle;
struct list_head dev_list;
};
LIST_HEAD( full_dev_list );
static struct ds_axidma_device *get_elem_from_list_by_inode(struct inode *i)
{
struct list_head *pos;
struct ds_axidma_device *obj_dev = NULL;
list_for_each( pos, &full_dev_list ) {
struct ds_axidma_device *tmp;
tmp = list_entry( pos, struct ds_axidma_device, dev_list );
if (tmp->dev_num == i->i_rdev)
{
obj_dev = tmp;
break;
}
}
return obj_dev;
}
// static void dmaHalt(void){
// unsigned long mm2s_halt = ioread32(virt_bus_addr + MM2S_DMASR) & 0x1;
// unsigned long s2mm_halt = ioread32(virt_bus_addr + S2MM_DMASR) & 0x1;
// int count = 0;
// printk(KERN_INFO "Halting...\n");
// iowrite32(0, virt_bus_addr + S2MM_DMACR);
// iowrite32(0, virt_bus_addr + MM2S_DMACR);
// while( !mm2s_halt || !s2mm_halt){
// // mm2s_halt = ioread32(virt_bus_addr + MM2S_DMASR) & 0x1;
// mm2s_halt = virt_bus_addr[MM2S_DMASR] & 0x1;
// //s2mm_halt = ioread32(virt_bus_addr + S2MM_DMASR) & 0x1;
// s2mm_halt = virt_bus_addr[S2MM_DMASR] & 0x1;
// count++;
// if (count>100 )
// {
// break;
// }
// }
// printk(KERN_INFO "DMA Halted!\n");
// }
static int my_strcmp(const char *str1, const char *str2)
{
int i;
i = 0;
while (str1[i] || str2[i])
{
if (str1[i] != str2[i])
return (str1[i] - str2[i]);
i++;
}
return (0);
}
static int dmaSynchMM2S(struct ds_axidma_device *obj_dev){
// sleep(6);
// return;
unsigned int mm2s_status = ioread32(obj_dev->virt_bus_addr + MM2S_DMASR);
while(!(mm2s_status & 1<<12) || !(mm2s_status & 1<<1) ){
mm2s_status = ioread32(obj_dev->virt_bus_addr + MM2S_DMASR);
}
return 0;
}
static int dmaSynchS2MM(struct ds_axidma_device *obj_dev){
unsigned int s2mm_status = ioread32(obj_dev->virt_bus_addr + S2MM_DMASR);
while(!(s2mm_status & 1<<12) || !(s2mm_status & 1<<1)){
s2mm_status = ioread32(obj_dev->virt_bus_addr + S2MM_DMASR);
}
return 0;
}
static int ds_axidma_open(struct inode *i, struct file *f)
{
/* printk(KERN_INFO "<%s> file: open()\n", MODULE_NAME); */
struct ds_axidma_device *obj_dev = get_elem_from_list_by_inode(i);
if (!request_mem_region(obj_dev->bus_addr, obj_dev->bus_size, MODULE_NAME))
{
return -1;
}
obj_dev->virt_bus_addr = (char *) ioremap_nocache(obj_dev->bus_addr, obj_dev->bus_size);
return 0;
}
static int ds_axidma_close(struct inode *i, struct file *f)
{
/* printk(KERN_INFO "<%s> file: close()\n", MODULE_NAME); */
struct ds_axidma_device *obj_dev = get_elem_from_list_by_inode(i);
iounmap(obj_dev->virt_bus_addr);
release_mem_region(obj_dev->bus_addr, obj_dev->bus_size);
return 0;
}
static ssize_t ds_axidma_read(struct file *f, char __user * buf, size_t
len, loff_t * off)
{
/* printk(KERN_INFO "<%s> file: read()\n", MODULE_NAME); */
struct ds_axidma_device *obj_dev;
if (len >= DMA_LENGTH)
{
return 0;
}
obj_dev = get_elem_from_list_by_inode(f->f_inode);
iowrite32(1, obj_dev->virt_bus_addr + S2MM_DMACR);
iowrite32(obj_dev->ds_axidma_handle, obj_dev->virt_bus_addr + S2MM_DA);
iowrite32(len, obj_dev->virt_bus_addr + S2MM_LENGTH);
dmaSynchS2MM(obj_dev);
memcpy(buf, obj_dev->ds_axidma_addr, len);
return len;
}
static ssize_t ds_axidma_write(struct file *f, const char __user * buf,
size_t len, loff_t * off)
{
/* printk(KERN_INFO "<%s> file: write()\n", MODULE_NAME); */
struct ds_axidma_device *obj_dev;
if (len >= DMA_LENGTH)
{
return 0;
}
obj_dev = get_elem_from_list_by_inode(f->f_inode);
memcpy(obj_dev->ds_axidma_addr, buf, len);
// printk(KERN_INFO "%X\n", ioread32(virt_bus_addr + MM2S_DMASR));
// printk(KERN_INFO "%X\n", ioread32(virt_bus_addr + MM2S_DMACR));
// printk(KERN_INFO "%X\n", ioread32(virt_bus_addr + S2MM_DMASR));
// printk(KERN_INFO "%X\n", ioread32(virt_bus_addr + S2MM_DMACR));
iowrite32(1, obj_dev->virt_bus_addr + MM2S_DMACR);
iowrite32(obj_dev->ds_axidma_handle, obj_dev->virt_bus_addr + MM2S_SA);
iowrite32(len, obj_dev->virt_bus_addr + MM2S_LENGTH);
// dmaSynchMM2S(obj_dev);
// printk(KERN_INFO "%X\n", ioread32(virt_bus_addr + MM2S_DMASR));
// printk(KERN_INFO "%X\n", ioread32(virt_bus_addr + MM2S_DMACR));
// printk(KERN_INFO "%X\n", ioread32(virt_bus_addr + S2MM_DMASR));
// printk(KERN_INFO "%X\n", ioread32(virt_bus_addr + S2MM_DMACR));
// printk(KERN_INFO "%X\n", bus_addr);
// printk(KERN_INFO "%lu\n", bus_size);
return len;
}
static struct file_operations fops = {
.owner = THIS_MODULE,
.open = ds_axidma_open,
.release = ds_axidma_close,
.read = ds_axidma_read,
.write = ds_axidma_write,
/* .mmap = ds_axidma_mmap, */
/* .unlocked_ioctl = ds_axidma_ioctl, */
};
static int ds_axidma_pdrv_probe(struct platform_device *pdev)
{
/* device constructor */
struct ds_axidma_device *obj_dev = (struct ds_axidma_device *)
kmalloc( sizeof(struct ds_axidma_device), GFP_KERNEL );
obj_dev->bus_addr = pdev->resource[0].start;
obj_dev->bus_size = pdev->resource[0].end - pdev->resource[0].start + 1;
obj_dev->dev_name = pdev->name + 9;
printk(KERN_INFO "<%s> init: registered\n", obj_dev->dev_name);
if (alloc_chrdev_region(&(obj_dev->dev_num), 0, 1, obj_dev->dev_name) < 0) {
return -1;
}
if (cl == NULL && (cl = class_create(THIS_MODULE, "chardrv")) == NULL) {
unregister_chrdev_region(obj_dev->dev_num, 1);
return -1;
}
if (device_create(cl, NULL, obj_dev->dev_num, NULL, obj_dev->dev_name) == NULL) {
class_destroy(cl);
unregister_chrdev_region(obj_dev->dev_num, 1);
return -1;
}
cdev_init(&(obj_dev->c_dev), &fops);
if (cdev_add(&(obj_dev->c_dev), obj_dev->dev_num, 1) == -1) {
device_destroy(cl, obj_dev->dev_num);
class_destroy(cl);
unregister_chrdev_region(obj_dev->dev_num, 1);
return -1;
}
printk(KERN_INFO "DMA_LENGTH = %u \n", DMA_LENGTH);
/* allocate mmap area */
obj_dev->ds_axidma_addr =
dma_zalloc_coherent(NULL, DMA_LENGTH, &(obj_dev->ds_axidma_handle), GFP_KERNEL);
list_add( &obj_dev->dev_list, &full_dev_list );
return 0;
}
static int ds_axidma_pdrv_remove(struct platform_device *pdev)
{
/* device destructor */
struct list_head *pos, *q;
list_for_each_safe( pos, q, &full_dev_list ) {
struct ds_axidma_device *obj_dev;
obj_dev = list_entry( pos, struct ds_axidma_device, dev_list );
if (!my_strcmp(obj_dev->dev_name, pdev->name + 9))
{
list_del( pos );
cdev_del(&(obj_dev->c_dev));
device_destroy(cl, obj_dev->dev_num);
unregister_chrdev_region(obj_dev->dev_num, 1);
/* free mmap area */
if (obj_dev->ds_axidma_addr) {
dma_free_coherent(NULL, DMA_LENGTH, obj_dev->ds_axidma_addr, obj_dev->ds_axidma_handle);
}
kfree(obj_dev);
break;
}
}
if (list_empty(&full_dev_list))
{
class_destroy(cl);
}
printk(KERN_INFO "<%s> exit: unregistered\n", MODULE_NAME);
return 0;
}
static int ds_axidma_pdrv_runtime_nop(struct device *dev)
{
/* Runtime PM callback shared between ->runtime_suspend()
* and ->runtime_resume(). Simply returns success.
*
* In this driver pm_runtime_get_sync() and pm_runtime_put_sync()
* are used at open() and release() time. This allows the
* Runtime PM code to turn off power to the device while the
* device is unused, ie before open() and after release().
*
* This Runtime PM callback does not need to save or restore
* any registers since user space is responsbile for hardware
* register reinitialization after open().
*/
return 0;
}
static const struct dev_pm_ops ds_axidma_pdrv_dev_pm_ops = {
.runtime_suspend = ds_axidma_pdrv_runtime_nop,
.runtime_resume = ds_axidma_pdrv_runtime_nop,
};
static struct of_device_id ds_axidma_of_match[] = {
{ .compatible = "ds_axidma", },
{ /* This is filled with module_parm */ },
{ /* Sentinel */ },
};
MODULE_DEVICE_TABLE(of, ds_axidma_of_match);
module_param_string(of_id, ds_axidma_of_match[1].compatible, 128, 0);
MODULE_PARM_DESC(of_id, "Openfirmware id of the device to be handled by uio");
static struct platform_driver ds_axidma_pdrv = {
.probe = ds_axidma_pdrv_probe,
.remove = ds_axidma_pdrv_remove,
.driver = {
.name = DRIVER_NAME,
.owner = THIS_MODULE,
.pm = &ds_axidma_pdrv_dev_pm_ops,
.of_match_table = of_match_ptr(ds_axidma_of_match),
},
};
module_platform_driver(ds_axidma_pdrv);
MODULE_AUTHOR("Fabrizio Spada, Gianluca Durelli");
MODULE_DESCRIPTION("AXI DMA driver");
MODULE_LICENSE("GPL v2");
3.编译,生成BOOT.BIN文件
images/linux/目录下将生成的BOOT.BIN和image.ub文件拷贝到SD卡,插上SD卡。启动串口敲入用户名和密码(均root):
这里可以看到ds_axidma.ko这个内核module。同时可以看到apps
测试方法如下:
至此,DMA的简单实例就完成了,PS侧的DMA可以参考Audio侧,另外,如果有一些文件挂载分区,则如下: