下面以一个按键的实验作为驱动分离时间简单学习：
1 #include <linux/module.h> 2 #include <linux/version.h> 3 4 #include <linux/init.h> 5 6 #include <linux/kernel.h> 7 #include <linux/types.h> 8 #include <linux/interrupt.h> 9 #include <linux/list.h> 10 #include <linux/timer.h> 11 #include <linux/init.h> 12 #include <linux/serial_core.h> 13 #include <linux/platform_device.h> 14 15 16 /* 分配/设置/注册一个platform_device */ 17 18 static struct resource led_resource[] = { 19 [0] = { 20 .start = 0x56000050, 21 .end = 0x56000050 + 8 - 1, 22 .flags = IORESOURCE_MEM, 23 }, 24 [1] = { 25 .start = 5, 26 .end = 5, 27 .flags = IORESOURCE_IRQ, 28 } 29 30 }; 31 32 static void led_release(struct device * dev) 33 { 34 } 35 36 37 static struct platform_device led_dev = { 38 .name = "myled", 39 .id = -1, 40 .num_resources = ARRAY_SIZE(led_resource), 41 .resource = led_resource, 42 .dev = { 43 .release = led_release, 44 }, 45 }; 46 47 static int led_dev_init(void) 48 { 49 platform_device_register(&led_dev); 50 return 0; 51 } 52 53 static void led_dev_exit(void) 54 { 55 platform_device_unregister(&led_dev); 56 } 57 58 module_init(led_dev_init); 59 module_exit(led_dev_exit); 60 61 MODULE_LICENSE("GPL");
1 /* 分配/设置/注册一个platform_driver */ 2 3 #include <linux/module.h> 4 #include <linux/version.h> 5 6 #include <linux/init.h> 7 #include <linux/fs.h> 8 #include <linux/interrupt.h> 9 #include <linux/irq.h> 10 #include <linux/sched.h> 11 #include <linux/pm.h> 12 #include <linux/sysctl.h> 13 #include <linux/proc_fs.h> 14 #include <linux/delay.h> 15 #include <linux/platform_device.h> 16 #include <linux/input.h> 17 #include <linux/irq.h> 18 #include <asm/uaccess.h> 19 #include <asm/io.h> 20 21 static int major; 22 23 24 static struct class *cls; 25 static volatile unsigned long *gpio_con; 26 static volatile unsigned long *gpio_dat; 27 static int pin; 28 29 static int led_open(struct inode *inode, struct file *file) 30 { 31 //printk("first_drv_open\n"); 32 /* 配置为输出 */ 33 *gpio_con &= ~(0x3<<(pin*2)); 34 *gpio_con |= (0x1<<(pin*2)); 35 return 0; 36 } 37 38 static ssize_t led_write(struct file *file, const char __user *buf, size_t count, loff_t * ppos) 39 { 40 int val; 41 42 //printk("first_drv_write\n"); 43 44 copy_from_user(&val, buf, count); // copy_to_user(); 45 46 if (val == 1) 47 { 48 // 点灯 49 *gpio_dat &= ~(1<<pin); 50 } 51 else 52 { 53 // 灭灯 54 *gpio_dat |= (1<<pin); 55 } 56 57 return 0; 58 } 59 60 61 static struct file_operations led_fops = { 62 .owner = THIS_MODULE, /* 这是一个宏，推向编译模块时自动创建的__this_module变量 */ 63 .open = led_open, 64 .write = led_write, 65 }; 66 67 static int led_probe(struct platform_device *pdev) 68 { 69 struct resource *res; 70 71 /* 根据platform_device的资源进行ioremap */ 72 res = platform_get_resource(pdev, IORESOURCE_MEM, 0); 73 gpio_con = ioremap(res->start, res->end - res->start + 1); 74 gpio_dat = gpio_con + 1; 75 76 res = platform_get_resource(pdev, IORESOURCE_IRQ, 0)