4、JZ2440按键驱动（poll）
驱动程序
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 <linux/irq.h> 7 #include <asm/uaccess.h> 8 #include <asm/irq.h> 9 #include <asm/io.h> 10 #include <asm/arch/regs-gpio.h> 11 #include <asm/hardware.h> 12 #include <linux/poll.h> 13 14 #define DEVICE_NAME "key_dev3" /* 加载模式后，执行”cat /proc/devices”命令看到的设备名称 */ 15 16 static struct class *key_class; 17 static struct class_device *key_class_dev; 18 19 volatile unsigned long *gpfcon; 20 volatile unsigned long *gpfdat; 21 22 volatile unsigned long *gpgcon; 23 volatile unsigned long *gpgdat; 24 25 /* 创建以个等待队列头 */ 26 static DECLARE_WAIT_QUEUE_HEAD(key_waitq); 27 28 /* 中断事件标志, 中断服务程序将它置1，third_drv_read将它清0 */ 29 static volatile int ev_press = 0; 30 31 struct pin_desc{ 32 unsigned int pin; 33 unsigned int key_val; 34 }; 35 /* 键值: 按下时, 0x01, 0x02, 0x03, 0x04 */ 36 /* 键值: 松开时, 0x81, 0x82, 0x83, 0x84 */ 37 static unsigned char key_val; 38 39 struct pin_desc pins_desc[4] = { 40 {S3C2410_GPF0, 0x01}, 41 {S3C2410_GPF2, 0x02}, 42 {S3C2410_GPG3, 0x03}, 43 {S3C2410_GPG11, 0x04}, 44 }; 45 46 /* 47 * 确定按键值 48 */ 49 static irqreturn_t keys_irq(int irq, void *dev_id) 50 { 51 struct pin_desc * pindesc = (struct pin_desc *)dev_id; 52 unsigned int pinval; 53 54 pinval = s3c2410_gpio_getpin(pindesc->pin); 55 56 if (pinval) 57 { 58 /* 松开 */ 59 key_val = 0x80 | pindesc->key_val; 60 } 61 else 62 { 63 /* 按下 */ 64 key_val = pindesc->key_val; 65 } 66 67 ev_press = 1; /* 表示中断发生了 */ 68 wake_up_interruptible(&key_waitq); /* 唤醒休眠的进程 */ 69 return IRQ_RETVAL(IRQ_HANDLED); 70 } 71 72 static int key_dev3_open(struct inode *inode, struct file *file) 73 { 74 /* 配置GPF0,2为输入引脚 */ 75 /* 配置GPG3,11为输入引脚 */ 76 request_irq(IRQ_EINT0, keys_irq, IRQT_BOTHEDGE, "S2", &pins_desc[0]); 77 request_irq(IRQ_EINT2, keys_irq, IRQT_BOTHEDGE, "S3", &pins_desc[1]); 78 request_irq(IRQ_EINT11, keys_irq, IRQT_BOTHEDGE, "S4", &pins_desc[2]); 79 request_irq(IRQ_EINT19, keys_irq, IRQT_BOTHEDGE, "S5", &pins_desc[3]); 80 81 return 0; 82 } 83 84 ssize_t key_dev3_read(struct file *file, char __user *buf, size_t size, loff_t *ppos) 85 { 86 if (size != 1) 87 return -EINVAL; 88 89 /* 如果没有按键动作, 休眠 */ 90 wait_event_interruptible(key_waitq, ev_press); 91 92 /* 如果有按键动作, 返回键值 */ 93 copy_to_user(buf, &key_val, 1); 94 ev_press = 0; 95 return 1; 96 } 97 98 int key_dev3_close(struct inode *inode, struct file *file) 99 { 100 free_irq(IRQ_EINT0, &pins_desc[0]); 101 free_irq(IRQ_EINT2, &pins_desc[1]); 102 free_irq(IRQ_EINT11, &pins_desc[2]); 103 free_irq(IRQ_EINT19, &pins_desc[3]); 104 return 0; 105 } 106 107 static unsigned key_dev3_poll(struct file *file, poll_table *wait) 108 { 109 unsigned int mask = 0; 110 poll_wait(file,&key_waitq,wait); 111 if (ev_press) 112 mask |= POLLIN | POLLRDNORM; 113 114 return mask; 115 } 116 117 static struct file_operations sencod_drv_fops = { 118 .owner = THIS_MODULE, /* 这是一个宏，推向编译模块时自动创建的__this_module变量 */ 119 .open = key_dev3_open, 120 .read = key_dev3_read, 121 .release = key_dev3_close, 122 .poll = key_dev3_poll, 123 124 }; 125 126 int major; 127 static int key_drv_init(void) 128 { 129 major = register_chrdev(0, DEVICE_NAME, &sencod_drv_fops); 130 131 key_class = class_create(THIS_MODULE, DEVICE_NAME); 132 133 key_class_dev = class_device_create(key_class, NULL, MKDEV(major, 0), NULL, DEVICE_NAME); /* /dev/keys */ 134 135 gpfcon = (volatile unsigned long *)ioremap(0x56000050, 16); 136 gpfdat = gpfcon + 1; 137 138 gpgcon = (volatile unsigned long *)ioremap(0x56000060, 16); 139 gpgdat = gpgcon + 1; 140 141 return 0; 142 } 143 144 static void key_drv_exit(void) 145 { 146 unregister_chrdev(major, DEVICE_NAME); 147 class_device_unregister(key_class_dev); 148 class_destroy(key_class); 149 iounmap(gpfcon); 150 iounmap(gpgcon); 151 return 0; 152 } 153 154 module_init(key_drv_init); 155 156 module_exit(key_drv_exit); 157 158 MODULE_LICENSE("GPL");
测试程序
1 #include <sys/types.h> 2 #include <sys/stat.h> 3 #include <fcntl.h> 4 #include <stdio.h> 5 #include <poll.h> 6 7 /* thirddrvtest 8 */ 9 int main(int argc, char **argv) 10 { 11 int fd; 12 unsigned char key_val; 13 int ret; 14 15 struct pollfd fds[1]; 16 17 fd = open("/dev/key_dev3", O_RDWR); 18 if (fd < 0) 19 { 20 printf("can't open!\n"); 21 } 22 23 fds[0].fd = fd; 24 fds[0].events = POLLIN; 25 while (1) 26 { 27 ret = poll(fds, 1, 5000); 28 if (ret == 0) 29 { 30 printf("time out\n"); 31 } 32 else 33 { 34 read(fd, &key_val, 1); 35 printf("key_val = 0x%x\n", key_val); 36 } 37 } 38 39 return 0; 40 }
Makefile
1 KERN_DIR = /work/system/linux-2.6.22.6 2 3 all: 4 make -C $(KERN_DIR) M=`pwd` modules 5 6 clean: 7 make -C $(KERN_DIR) M=`pwd` modules clean 8 rm -rf modules.order 9 obj-m += key_dev3.o
