zynq驱动-4ioremap的字符设备驱动

#include <linux/types.h> #include <linux/kernel.h> #include <linux/delay.h> #include <linux/ide.h> #include <linux/init.h> #include <linux/module.h> #include <linux/errno.h> #include <linux/gpio.h> #include <asm/mach/map.h> #include <asm/uaccess.h> #include <asm/io.h> #include <linux/cdev.h> #define USING_REGISTER_CHRDRV // #define AXI_GPIO_ADDR 0x41210000 #define AXI_GPIO_ADDR4 0x41210004 void __iomem *led_addr; void __iomem *led_addr4; void led_ioremap(void) { int a,b; led_addr=ioremap(AXI_GPIO_ADDR,4); led_addr4=ioremap(AXI_GPIO_ADDR4,4); a=(int)led_addr; b=(int)led_addr4; printk("a=%x,b=%x\r\n",a,b); writel(0xff,led_addr); } char buf_read[100]={"data from kernel"}; char buf_write[100]={"data to kernel"}; #define CHRDEV_NAME "chrdev" #define CHRDEV_COUNT 1 typedef struct{ dev_t devid; int major; int minor; struct cdev cdev; struct class *class; struct device *device; } chrdev_struct; chrdev_struct led; static int led_open(struct inode *inode, struct file *filp) { filp->private_data = &led; /* 设置私有数据 */ return 0; } static ssize_t led_read(struct file *filp, char __user *buf, size_t cnt, loff_t *offt) { copy_to_user(buf,buf_read,cnt); return 0; } static ssize_t led_write(struct file *filp, const char __user *buf, size_t cnt, loff_t *offt) { int data; copy_from_user(&data,buf,4); writel(data,led_addr); printk("led_write,data=%d\r\n",data); return 0; } static int led_close(struct inode *inode, struct file *filp) { return 0; } struct file_operations led_fops={ .owner=THIS_MODULE, .open=led_open, .write=led_write, .read=led_read, .release=led_close, }; static int __init chardrv_init(void) { int ret; led_ioremap(); #ifdef USING_REGISTER_CHRDRV //1.device id led.major=register_chrdev(0,CHRDEV_NAME,&led_fops); printk("major=%d,minor=%d\r\n",led.major,0); led.devid=MKDEV(led.major,0); #else //1.alloc device id ret=alloc_chrdev_region(&led.devid,0,CHRDEV_COUNT,CHRDEV_NAME); if(ret) goto error1; led.major=MAJOR(led.devid); led.minor=MINOR(led.devid); printk("major=%d,minor=%d\r\n",led.major,led.minor); //2.init cdev led.cdev.owner=THIS_MODULE; cdev_init(&led.cdev,&led_fops); ret=cdev_add(&led.cdev,led.devid,CHRDEV_COUNT); if(ret) goto error2; printk("chardev_init\n"); #endif //3.create class led.class=class_create(THIS_MODULE,"led_class_name"); if(IS_ERR(led.class)) { goto error3; } //4.create device led.device=device_create( led.class, NULL, led.devid, NULL, "led_device" ); if(IS_ERR(led.device)) { goto error4; } return 0; error4: class_destroy(led.class); error3: #ifdef USING_REGISTER_CHRDRV #else cdev_del(&led.cdev); #endif error2: #ifdef USING_REGISTER_CHRDRV unregister_chrdev(led.major,CHRDEV_NAME); #else unregister_chrdev_region(led.devid,CHRDEV_COUNT); #endif error1: iounmap(led_addr); iounmap(led_addr4); return -1; } static void __exit chardrv_exit(void) { writeb(0x0,led_addr); device_destroy(led.class,led.devid); class_destroy(led.class); #ifdef USING_REGISTER_CHRDRV cdev_del(&led.cdev); unregister_chrdev(led.major,CHRDEV_NAME); #else unregister_chrdev_region(led.devid,CHRDEV_COUNT); #endif iounmap(led_addr); iounmap(led_addr4); printk("chardev_exit\n"); //return 0; } module_init(chardrv_init); module_exit(chardrv_exit); MODULE_LICENSE("GPL");