1 #include <linux/module.h> 2 #include <linux/kernel.h> 3 #include <linux/fs.h> 4 #include <linux/init.h> 5 #include <linux/delay.h> 6 #include <asm/io.h> 7 #include <linux/cdev.h> 8 #include <linux/device.h> 9 #include <linux/bitmap.h> 10 #include <asm/gpio.h> 11 #include <linux/platform_device.h> 12 #include <linux/slab.h> 13 #include <linux/sched.h> 14 #include <linux/of.h> 15 16 static volatile unsigned long *ledcon; 17 static volatile unsigned long *leddat; 18 static struct class *led_class; 19 static unsigned int pin_th; 20 dev_t led_dev; 21 struct cdev *cdev; 22 23 24 /* 打开led灯 */ 25 static int led_open(struct inode *inode, struct file *file) 26 { 27 *ledcon &= ~(0x3 << (pin_th * 2)); 28 *ledcon |= (0x1 << (pin_th * 2)); 29 *leddat &= ~(1 << pin_th); 30 return 0; 31 } 32 33 static struct file_operations led_fops = { 34 .owner = THIS_MODULE, 35 .open = led_open, 36 }; 37 38 static int led_probe(struct platform_device *pdev) 39 { 40 int pin_info; 41 int phy_addr; 42 int io_base; 43 of_property_read_s32(pdev->dev.of_node, "pin", &pin_info); 44 printk("pin_info = 0x%x ", pin_info); 45 of_property_read_s32(pdev->dev.of_node, "iobase", &io_base); 46 printk("io_base = 0x%x ", io_base); 47 pin_th = pin_info & (0xffff); 48 phy_addr = (io_base | ((pin_info>>16)<<4)); 49 ledcon = ioremap(phy_addr, 2); 50 leddat = ledcon + 1; 51 52 if (alloc_chrdev_region(&led_dev, MINOR(led_dev), 1, "led")) 53 return -1; 54 cdev = cdev_alloc(); 55 if (!cdev) 56 return -1; 57 cdev_init(cdev, &led_fops); 58 cdev_add(cdev, led_dev, 1); 59 60 led_class = class_create(THIS_MODULE, "led"); 61 device_create(led_class,NULL,led_dev,NULL,"led0"); // is /dev/led0 62 63 return 0; 64 65 } 66 67 int led_remove(struct platform_device *pdev) 68 { 69 device_destroy(led_class, led_dev); 70 class_destroy(led_class); 71 cdev_del(cdev); 72 unregister_chrdev_region(led_dev, 1); 73 iounmap(ledcon); 74 return 0; 75 } 76 77 static struct of_device_id led_id[] = { 78 {.compatible = "jz2440_led"}, 79 {}, 80 }; 81 82 static struct platform_driver led_drv = { 83 .probe = led_probe, 84 .remove = led_remove, 85 .driver = { 86 .name = "jz2440_led", 87 .of_match_table = led_id, 88 }, 89 }; 90 91 static int led_init(void) 92 { 93 platform_driver_register(&led_drv); 94 return 0; 95 } 96 97 static void led_exit(void) 98 { 99 platform_driver_unregister(&led_drv); 100 } 101 102 module_init(led_init); 103 module_exit(led_exit); 104 105 MODULE_LICENSE("GPL");
以上是驱动程序，下面是设备树dts文件：
1 #define S3C2440_GPA(_nr) ((0<<16) + (_nr)) 2 #define S3C2440_GPB(_nr) ((1<<16) + (_nr)) 3 #define S3C2440_GPC(_nr) ((2<<16) + (_nr)) 4 #define S3C2440_GPD(_nr) ((3<<16) + (_nr)) 5 #define S3C2440_GPE(_nr) ((4<<16) + (_nr)) 6 #define S3C2440_GPF(_nr) ((5<<16) + (_nr)) 7 #define S3C2440_GPG(_nr) ((6<<16) + (_nr)) 8 #define S3C2440_GPH(_nr) ((7<<16) + (_nr)) 9 #define S3C2440_GPJ(_nr) ((8<<16) + (_nr)) 10 #define S3C2440_GPK(_nr) ((9<<16) + (_nr)) 11 #define S3C2440_GPL(_nr) ((10<<16) + (_nr)) 12 #define S3C2440_GPM(_nr) ((11<<16) + (_nr)) 13 14 /dts-v1/; 15 16 / { 17 model = "SMDK2440"; 18 compatible = "samsung,smdk2440"; 19 20 #address-cells = <1>; 21 #size-cells = <1>; 22 23 memory@30000000 { 24 device_type = "memory"; 25 reg = <0x30000000 0x4000000>; 26 };
34 chosen { 35 bootargs = "noinitrd root=/dev/mtdblock4 rw init=/linuxrc console=ttySAC0,115200"; 36 }; 37 38 39 led { 40 compatible = "jz2440_led"; 41 pin = <S3C2440_GPF(5)>; 42 iobase = <0x56000000>; 43 }; 44 };