zynq的linux驱动12-阻塞IO

#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> #include <linux/of.h> #include <linux/of_address.h> #include <linux/of_gpio.h> #include <linux/of_irq.h> #include <linux/irq.h> struct str_key{ int major; dev_t devid; struct class *class; struct device *device; struct cdev cdev; struct device_node *nd; int key_gpio; struct mutex lock; int key_irq_num; //int led_used; wait_queue_head_t r_wait; } key; enum key_status { KEY_PRESS = 0, // 按键按下 KEY_RELEASE, // 按键松开 KEY_KEEP, // 按键状态保持 }; static atomic_t status; /* 按键状态 */ irqreturn_t key_irq_func(int irq,void *dev_id) { printk("kernel:key press\r\n"); //status=KEY_PRESS; atomic_set(&status,KEY_PRESS); wake_up_interruptible(&key.r_wait); return IRQ_HANDLED; } int key_init_from_dts_using_gpio(void) { int ret; const char *str; int irq_flags; /* 1.获取led设备节点 */ key.nd = of_find_node_by_path("/key"); if(NULL == key.nd) { printk(KERN_ERR "key_gpio node can not found!\r\n"); return -1; } /* 2.读取status属性 */ ret = of_property_read_string(key.nd, "status", &str); if(!ret) { if (strcmp(str, "okay")) return -1; } /* 2、获取compatible属性值并进行匹配 */ ret = of_property_read_string(key.nd, "compatible", &str); if(0 > ret) return -1; if (strcmp(str, "xhl,key_gpio")) return -1; printk(KERN_ERR "key device matching successful!\r\n"); //led_ioremap(); //key.key_gpio=of_get_named_gpio(key.nd,"gpios",0); key.key_gpio=of_get_gpio(key.nd,0); if(key.key_gpio<0) return -1; ret=gpio_request(key.key_gpio,"key_gpio"); if(ret) return -1; printk("key_gpio=%d\r\n",key.key_gpio); gpio_direction_input(key.key_gpio); //中断处理 //1.申请中断号 key.key_irq_num=irq_of_parse_and_map(key.nd,0); printk("key_irq_num=%d\r\n",key.key_irq_num); //2.获取中断类型 irq_flags=irq_get_trigger_type(key.key_irq_num); //3.申请中断 ret=request_irq(key.key_irq_num,key_irq_func,irq_flags,"key irq",NULL); if(ret<0) { gpio_free(key.key_gpio); return ret; } return ret; } static int mio_set(int value) { //u32 val; //int ret; if(value==0) { gpio_set_value(key.key_gpio,0); } else { gpio_set_value(key.key_gpio,1); } /* 6.默认关闭LED */ /*val = readl(data_addr); if(value==0) { val &= ~(0x1U << 7); } else { val |= (0x1U << 7); } writel(val, data_addr);*/ return 0; } #define KEY_NUM 1 #define KEY_NAME "key" int key_open(struct inode *inode,struct file *file) { int ret=0; /*unsigned long flags; spin_lock_irqsave(&key.lock,flags); if(key.led_used) { spin_unlock_irqrestore(&key.lock,flags); return -1; } key.led_used=1; spin_unlock_irqrestore(&key.lock,flags); */ if(mutex_lock_interruptible(&key.lock)) return -1; printk("kernel:key_open\r\n"); return ret; } int key_close(struct inode *inode,struct file *file) { int ret=0; /*unsigned long flags; spin_lock_irqsave(&key.lock,flags); if(key.led_used) { key.led_used=0; //spin_unlock_irqrestore(&key.lock,flags); //return -1; } spin_unlock_irqrestore(&key.lock,flags); */ mutex_unlock(&key.lock); //atomic_inc(&key.lock); printk("kernel:key_close\r\n"); return ret; } ssize_t key_write(struct file *file, const char __user *buf, size_t len, loff_t *ppos) { int ret=0; char *write_buf; write_buf=(char *)kmalloc(len,GFP_KERNEL); if(write_buf==NULL) return -1; ret=copy_from_user(write_buf,buf,1); if(ret<0) return -1; if(write_buf[0]==0) mio_set(0); else { mio_set(1); } //printk("kernel:key_write,buf=%s\r\n",write_buf); kfree(write_buf); return ret; } ssize_t key_read(struct file *file, char __user *buf, size_t len, loff_t *ppos) { int ret=0; //int read_buf=gpio_get_value(key.key_gpio); ret=wait_event_interruptible(key.r_wait,KEY_PRESS==atomic_read(&status)); if(ret) return ret; ret=copy_to_user(buf,&status,sizeof(int)); if(ret<0) return -1; atomic_set(&status,KEY_KEEP); //printk("kernel:key_value=%d,ret=%d\r\n",read_buf,ret); return ret; } struct file_operations ops={ .owner =THIS_MODULE, .open =key_open, .write =key_write, .read =key_read, .release=key_close, }; static int __init mykey_init(void) { int ret=0; //1.设备号 key.major=0; if(key.major) { key.devid=MKDEV(key.major,0); ret=register_chrdev_region(key.devid,KEY_NUM,KEY_NAME); } else { ret=alloc_chrdev_region(&key.devid,0,KEY_NUM,KEY_NAME); key.major=MAJOR(key.devid); } printk("major=%d\r\n",key.major); //2. key.class=class_create(THIS_MODULE,KEY_NAME); if(IS_ERR(key.class)) { printk("error:class_create\r\n"); ret=PTR_ERR(key.class); goto error_class_create; } //3. key.device=device_create(key.class,NULL,key.devid,NULL,KEY_NAME); if(IS_ERR(key.device)) { printk("error:device_create\r\n"); ret=PTR_ERR(key.device); goto error_device_create; } printk("device_create ok\r\n"); //4.添加设备 cdev_init(&key.cdev,&ops); ret=cdev_add(&key.cdev,key.devid,KEY_NUM); if(ret<0) { printk("error:cdev_add\r\n"); goto error_cdev_add; } printk("cdev_add ok\r\n"); //mio_init(); key_init_from_dts_using_gpio(); //atomic_set(&key.lock,1); //spin_lock_init(&key.lock); mutex_init(&key.lock); init_waitqueue_head(&key.r_wait); atomic_set(&status,KEY_KEEP); //key.led_used=0; printk("key_init2\r\n"); return ret; error_cdev_add: device_destroy(key.class, key.devid); error_device_create: class_destroy(key.class); error_class_create: unregister_chrdev_region(key.devid,KEY_NUM); return ret; } static void __exit mykey_exit(void) { /* 2.取消内存映射 */ /*iounmap(data_addr); iounmap(dirm_addr); iounmap(outen_addr); iounmap(intdis_addr); iounmap(aper_clk_ctrl_addr); */ free_irq(key.key_irq_num,NULL); cdev_del(&key.cdev); device_destroy(key.class, key.devid); class_destroy(key.class); unregister_chrdev_region(key.devid,KEY_NUM); printk("key_exit22\r\n"); //return 0; } module_init(mykey_init); module_exit(mykey_exit); MODULE_LICENSE("GPL");