linux设备树 驱动 (9条消息)zynq linux驱动之使用设备树开发

PC：Windows 10

虚拟机：ubuntu 16.04

vivado：.04

PetaLinux：.04

开发板：黑金AX7010

根文件系统：debian8

-------------------------------------------------- --------------------传说中的分割线------------------------- -------------------------------------------------- ------

首先回到的的PetaLinux的工程目录下：

find -name "system-top.dts"

cd ./components/plnx_workspace/device-tree/device-tree-generation/

进入该目录

ls

首先打开系统top.dts看一下

发现包涵了一个系统user.dtsi

回到工程根目录，然后查找一下系统user.dtsi

cd -

find -name "system-user.dtsi"

直接打开./project-spec/meta-user/recipes-bsp/device-tree/files/system-user.dtsi编辑

/include/ "system-conf.dtsi"

/ {

amba_pl: amba_pl{

#address-cells = <1>;

#size-cells = <1>;

compatible = "simple-bus";

ranges;

leds: leds@41200000{

compatible = "hello,leds";

reg = <0x41200000 0x1>;

};

};

};

使用的的PetaLinux编译一下工程

petalinux-build

编译完成后回到开发板

挂接NFS文件系统

把生成的system.dts文件拷贝到SD的fat分区里

过程略....

重启开发板

接下来编写驱动：

#include

#include

#include

#include

#include

#include

#include

#include

#include

#include

#include

#include

#include

#include

#include

#include

#include

#include

#include

#include

#include

#include

#include

#include

#include /* error codes */

#include

#include

#include

#include

#include

#include

#include

#include

#include

// 定义设备文件名

#define DEVICE_NAME "leds_drv"

//

static char devname[16];

static int major;

static int mijor;

static struct class*cls;

static void __iomem*base_address;

static resource_size_t remap_size;

static int irq;

static struct device*dev;

//

typedef struct{

volatile unsigned int ODR;

}LEDS_T;

LEDS_T* leds;

static int leds_drv_open(struct inode *Inode, struct file *File)

{

leds->ODR = 0xf;

return 0;

}

static ssize_t leds_drv_read(struct file *file, char __user *buf, size_t count, loff_t *ppos)

{

return 0;

}

static ssize_t leds_drv_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos)

{

unsigned int ret = 0;

unsigned int tmp_val;

ret = copy_from_user(&tmp_val, buf, count);

leds->ODR = (~tmp_val) & 0xf;

return ret;

}

// 描述与设备文件触发的事件对应的回调函数指针

static struct file_operations dev_fops =

{

.owner = THIS_MODULE,

.open = leds_drv_open,

.read = leds_drv_read,

.write = leds_drv_write,

};

static int leds_drv_probe(struct platform_device *pdev)

{

struct resource *res;

struct device *tmp_dev;

memset(devname,0,16);

strcpy(devname, DEVICE_NAME);

major = register_chrdev(0, devname, &dev_fops);

cls = class_create(THIS_MODULE, devname);

mijor = 0;

tmp_dev = device_create(cls, &pdev->dev, MKDEV(major, mijor), NULL, devname);

if (IS_ERR(tmp_dev)) {

class_destroy(cls);

unregister_chrdev(major, devname);

return 0;

}

//获取资源

res = platform_get_resource(pdev, IORESOURCE_MEM, 0);

if(res == NULL)

{

printk(KERN_ALERT "leds_drv_probe res error!\n");

return -ENOENT;

}

base_address = devm_ioremap_resource(&pdev->dev, res);

if (IS_ERR(base_address))

return PTR_ERR(base_address);

printk("base_address = 0x%08x\n", (unsigned int)base_address);

remap_size = resource_size(res);

printk("remap_size = 0x%08x\n", remap_size);

dev = &pdev->dev;

//保存dev数据

//platform_set_drvdata(pdev, &xxx);

leds = (LEDS_T*)base_address;

return 0;

}

static int leds_drv_remove(struct platform_device *pdev)

{

device_destroy(cls, MKDEV(major, mijor));

class_destroy(cls);

unregister_chrdev(major, devname);

devm_iounmap(&pdev->dev, base_address);

return 0;

}

static int leds_drv_suspend(struct device *dev)

{

return 0;

}

static int leds_drv_resume(struct device *dev)

{

return 0;

}

static const struct dev_pm_ops leds_drv_pm_ops = {

.suspend = leds_drv_suspend,

.resume = leds_drv_resume,

};

static const struct of_device_id leds_drv_of_match[] = {

{.compatible = "hello,leds" },

{ }

};

MODULE_DEVICE_TABLE(of, leds_drv_of_match);

static struct platform_driver leds_drv_driver = {

.probe = leds_drv_probe,

.remove= leds_drv_remove,

.driver = {

.owner = THIS_MODULE,

.name = "leds@41200000",

.pm = &leds_drv_pm_ops,

.of_match_table= leds_drv_of_match,

},

};

module_platform_driver(leds_drv_driver);

MODULE_LICENSE("GPL v2");

Makefile文件：

export ARCH=arm

KERN_DIR = /home/zynq/work/kernel/linux-4.9

all:

make -C $(KERN_DIR) M=`pwd` modules

clean:

make -C $(KERN_DIR) M=`pwd` modules clean

rm -rf modules.order

obj-m += leds_drv.o

执行一下

make

换到开发板，加载驱动：

编写测试程序：

#include

#include

#include

#include

#include

int main(int argc, char** argv)

{

int fd;

fd = open("/dev/leds_drv", O_RDWR);

if(fd < 0)

{

printf("fd = %d open fialed!\n", fd);

}

unsigned int leds = 0;

while(1)

{

write(fd, &leds, 4);

leds++;

leds %= 0xf;

sleep(1);

}

close(fd);

return 0;

}

编译测试程序：

arm-linux-gnueabihf-gcc -o leds leds.c

最后回到开发板

执行./leds

又一次看到4个led做加法了