zynq的linux驱动7-利用信号量实现竞争保护

#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> struct str_mioled{ int major; dev_t devid; struct class *class; struct device *device; struct cdev cdev; struct device_node *nd; int led_gpio; struct semaphore lock; int led_used; } mioled; //mio /* #define ZYNQ_GPIO_REG_BASE 0xE000A000 #define DATA_OFFSET (0+0x40) #define DIRM_OFFSET (0+0x204) #define OUTEN_OFFSET (0+0x208) #define INTDIS_OFFSET (0+0x214) #define APER_CLK_CTRL (0xF800012C) */ /* 映射后的寄存器虚拟地址指针 */ /*static void __iomem *data_addr; static void __iomem *dirm_addr; static void __iomem *outen_addr; static void __iomem *intdis_addr; static void __iomem *aper_clk_ctrl_addr; */ static inline void led_ioremap(void) { /*data_addr = of_iomap(mioled.nd, 0); dirm_addr = of_iomap(mioled.nd, 1); outen_addr = of_iomap(mioled.nd, 2); intdis_addr = of_iomap(mioled.nd, 3); aper_clk_ctrl_addr = of_iomap(mioled.nd, 4); */ } int mio_from_dts(void) { int ret; const char *str; /* 1.获取led设备节点 */ mioled.nd = of_find_node_by_path("/led_gpio"); if(NULL == mioled.nd) { printk(KERN_ERR "led_gpio node can not found!\r\n"); return -1; } /* 2.读取status属性 */ ret = of_property_read_string(mioled.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(mioled.nd, "compatible", &str); if(0 > ret) return -1; if (strcmp(str, "xhl,led_gpio")) return -1; printk(KERN_ERR "led device matching successful!\r\n"); //led_ioremap(); //mioled.led_gpio=of_get_named_gpio(mioled.nd,"gpios",0); mioled.led_gpio=of_get_gpio(mioled.nd,0); if(mioled.led_gpio<0) return -1; ret=gpio_request(mioled.led_gpio,"led_gpio"); if(ret) return -1; return ret; } int mio_from_dts_using_gpio(void) { int ret; const char *str; /* 1.获取led设备节点 */ mioled.nd = of_find_node_by_path("/led_gpio"); if(NULL == mioled.nd) { printk(KERN_ERR "led_gpio node can not found!\r\n"); return -1; } /* 2.读取status属性 */ ret = of_property_read_string(mioled.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(mioled.nd, "compatible", &str); if(0 > ret) return -1; if (strcmp(str, "xhl,led_gpio")) return -1; printk(KERN_ERR "led device matching successful!\r\n"); //led_ioremap(); //mioled.led_gpio=of_get_named_gpio(mioled.nd,"gpios",0); mioled.led_gpio=of_get_gpio(mioled.nd,0); if(mioled.led_gpio<0) return -1; ret=gpio_request(mioled.led_gpio,"led_gpio"); if(ret) return -1; gpio_direction_output(mioled.led_gpio, 0); return ret; } static int mio_set(int value) { //u32 val; //int ret; if(value==0) { gpio_set_value(mioled.led_gpio,0); } else { gpio_set_value(mioled.led_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 MIOLED_NUM 1 #define MIOLED_NAME "mioled" int mioled_open(struct inode *inode,struct file *file) { int ret=0; /*unsigned long flags; spin_lock_irqsave(&mioled.lock,flags); if(mioled.led_used) { spin_unlock_irqrestore(&mioled.lock,flags); return -1; } mioled.led_used=1; spin_unlock_irqrestore(&mioled.lock,flags); */ if(down_interruptible(&mioled.lock)) return -1; printk("kernel:mioled_open\r\n"); return ret; } int mioled_close(struct inode *inode,struct file *file) { int ret=0; /*unsigned long flags; spin_lock_irqsave(&mioled.lock,flags); if(mioled.led_used) { mioled.led_used=0; //spin_unlock_irqrestore(&mioled.lock,flags); //return -1; } spin_unlock_irqrestore(&mioled.lock,flags); */ up(&mioled.lock); //atomic_inc(&mioled.lock); printk("kernel:mioled_close\r\n"); return ret; } ssize_t mioled_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:mioled_write,buf=%s\r\n",write_buf); kfree(write_buf); return ret; } ssize_t mioled_read(struct file *file, char __user *buf, size_t len, loff_t *ppos) { int ret=0; int read_buf=(int)(&mioled); ret=copy_to_user(buf,&read_buf,sizeof(int)); if(ret<0) return -1; printk("kernel:mioled_read,addr=%d,ret=%d\r\n",read_buf,ret); return ret; } /* ssize_t led_read(struct file *filp, char __user *buf, size_t cnt, loff_t *offt) { return 0; } */ struct file_operations ops={ .owner =THIS_MODULE, .open =mioled_open, .write =mioled_write, .read =mioled_read, .release=mioled_close, }; static int __init mioled_init(void) { int ret=0; //1.设备号 mioled.major=0; if(mioled.major) { mioled.devid=MKDEV(mioled.major,0); ret=register_chrdev_region(mioled.devid,MIOLED_NUM,MIOLED_NAME); } else { ret=alloc_chrdev_region(&mioled.devid,0,MIOLED_NUM,MIOLED_NAME); mioled.major=MAJOR(mioled.devid); } printk("major=%d\r\n",mioled.major); //2. mioled.class=class_create(THIS_MODULE,MIOLED_NAME); if(IS_ERR(mioled.class)) { printk("error:class_create\r\n"); ret=PTR_ERR(mioled.class); goto error_class_create; } //3. mioled.device=device_create(mioled.class,NULL,mioled.devid,NULL,MIOLED_NAME); if(IS_ERR(mioled.device)) { printk("error:device_create\r\n"); ret=PTR_ERR(mioled.device); goto error_device_create; } printk("device_create ok\r\n"); //4.添加设备 cdev_init(&mioled.cdev,&ops); ret=cdev_add(&mioled.cdev,mioled.devid,MIOLED_NUM); if(ret<0) { printk("error:cdev_add\r\n"); goto error_cdev_add; } printk("cdev_add ok\r\n"); //mio_init(); mio_from_dts_using_gpio(); //atomic_set(&mioled.lock,1); //spin_lock_init(&mioled.lock); sema_init(&mioled.lock,1); mioled.led_used=0; printk("mioled_init2\r\n"); return ret; error_cdev_add: device_destroy(mioled.class, mioled.devid); error_device_create: class_destroy(mioled.class); error_class_create: unregister_chrdev_region(mioled.devid,MIOLED_NUM); return ret; } static void __exit mioled_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); */ cdev_del(&mioled.cdev); device_destroy(mioled.class, mioled.devid); class_destroy(mioled.class); unregister_chrdev_region(mioled.devid,MIOLED_NUM); printk("mioled_exit22\r\n"); //return 0; } module_init(mioled_init); module_exit(mioled_exit); MODULE_LICENSE("GPL");