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
虛擬機：ubuntu 16.04
vivado：2017.04
PetaLinux：2017.04
開發板：黑金AX7010
根文件系統：debian8
-------------------------------------------------- --------------------傳說中的分割線------------------------- -------------------------------------------------- ------
首先回到的的PetaLinux的工程目錄下：
find -name "system-top.dts"
cd ./components/plnx_workspace/device-tree/device-tree-generation/
進入該目錄
ls
首先打開系統top.dts看一下
發現包涵了一個系統user.dtsi
回到工程根目錄，然后查找一下系統user.dtsi
cd -
find -name "system-user.dtsi"
直接打開./project-spec/meta-user/recipes-bsp/device-tree/files/system-user.dtsi編輯
/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編譯一下工程
petalinux-build
編譯完成后回到開發板
掛接NFS文件系統
把生成的system.dts文件拷貝到SD的fat分區里
過程略....
重啟開發板
接下來編寫驅動：
#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
// 定義設備文件名
#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;
}
// 描述與設備文件觸發的事件對應的回調函數指針
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;
}
//獲取資源
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數據
//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
執行一下
make
換到開發板，加載驅動：
編寫測試程序：
#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;
}
編譯測試程序：
arm-linux-gnueabihf-gcc -o leds leds.c
最后回到開發板
執行./leds
又一次看到4個led做加法了
總結
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