三种方式下编写的按键驱动

#include <linux/module.h> #include <linux/kernel.h> #include <linux/fs.h> #include <linux/init.h> #include <linux/delay.h> #include <linux/poll.h> #include <linux/irq.h> #include <asm/irq.h> #include <asm/io.h> #include <linux/interrupt.h> #include <asm/uaccess.h> #include <mach/regs-gpio.h> #include <mach/hardware.h> #include <linux/platform_device.h> #include <linux/cdev.h> #include <linux/miscdevice.h> #include <linux/errno.h> #define DEVICE_NAME "mybuttons" #define KEYNUM_MAX 6 struct button_irq_desc { int irq; int pin; int pin_setting; int number; char *name; }; static struct button_irq_desc button_irqs [] = { {IRQ_EINT8 , S3C2410_GPG0 , S3C2410_GPG0_EINT8 , 0, "KEY0"}, {IRQ_EINT11, S3C2410_GPG3 , S3C2410_GPG3_EINT11 , 1, "KEY1"}, {IRQ_EINT13, S3C2410_GPG5 , S3C2410_GPG5_EINT13 , 2, "KEY2"}, {IRQ_EINT14, S3C2410_GPG6 , S3C2410_GPG6_EINT14 , 3, "KEY3"}, {IRQ_EINT15, S3C2410_GPG7 , S3C2410_GPG7_EINT15 , 4, "KEY4"}, {IRQ_EINT19, S3C2410_GPG11, S3C2410_GPG11_EINT19, 5, "KEY5"}, }; static volatile char key_values [] = {'0', '0', '0', '0', '0', '0'}; static DECLARE_WAIT_QUEUE_HEAD(button_waitq); static volatile int ev_press = 0; static void __iomem *s3c2410_key_base; static struct resource *s3c2410_key_mem; static irqreturn_t buttons_interrupt(int irq, void *dev_id) { struct button_irq_desc *button_irqs = (struct button_irq_desc *)dev_id; int down; int pin = button_irqs->pin-S3C2410_GPIO_BANKG; // udelay(0); // down = !s3c2410_gpio_getpin(button_irqs->pin); printk(KERN_ALERT "S3C2410_GPGDAT is 0x%x, pin is %d\n",S3C2410_GPGDAT,pin); down = readw(s3c2410_key_base + 4); printk(KERN_ALERT "key state is read,%X\n",down); down =!(down & (1<<(pin & 0x0f))); printk(KERN_ALERT "key state is read-----,%02X\n",down); if (down != (key_values[button_irqs->number] & 1)) { // Changed key_values[button_irqs->number] = '0' + down; ev_press = 1; wake_up_interruptible(&button_waitq); } return IRQ_RETVAL(IRQ_HANDLED); } static int s3c24xx_buttons_open(struct inode *inode, struct file *file) { int i; int err = 0; for (i = 0; i < sizeof(button_irqs)/sizeof(button_irqs[0]); i++) { if (button_irqs[i].irq < 0) { continue; } err = request_irq(button_irqs[i].irq, buttons_interrupt, IRQ_TYPE_EDGE_BOTH, button_irqs[i].name, (void *)&button_irqs[i]); if (err) { printk(KERN_ALERT "request_irq error,i=%d,irq=%d,err=%d\n",i,button_irqs[i].irq,err); break; } } if (err) { i--; for (; i >= 0; i--) { if (button_irqs[i].irq < 0) { continue; } disable_irq(button_irqs[i].irq); free_irq(button_irqs[i].irq, (void *)&button_irqs[i]); } return -EBUSY; } ev_press = 1; return 0; } static int s3c24xx_buttons_close(struct inode *inode, struct file *file) { int i; for (i = 0; i < sizeof(button_irqs)/sizeof(button_irqs[0]); i++) { if (button_irqs[i].irq < 0) { continue; } free_irq(button_irqs[i].irq, (void *)&button_irqs[i]); } return 0; } static int s3c24xx_buttons_read(struct file *filp, char __user *buff, size_t count, loff_t *offp) { unsigned long err; if (!ev_press) { if (filp->f_flags & O_NONBLOCK) return -EAGAIN; else wait_event_interruptible(button_waitq, ev_press); } ev_press = 0; err = copy_to_user(buff, (const void *)key_values, min(sizeof(key_values), count)); return err ? -EFAULT : min(sizeof(key_values), count); } static unsigned int s3c24xx_buttons_poll( struct file *file, struct poll_table_struct *wait) { unsigned int mask = 0; poll_wait(file, &button_waitq, wait); if (ev_press) mask |= POLLIN | POLLRDNORM; return mask; } static struct file_operations dev_fops = { .owner = THIS_MODULE, .open = s3c24xx_buttons_open, .release = s3c24xx_buttons_close, .read = s3c24xx_buttons_read, .poll = s3c24xx_buttons_poll, }; static struct miscdevice misc = { .minor = MISC_DYNAMIC_MINOR, .name = DEVICE_NAME, .fops = &dev_fops, }; static int __devinit s3c2410_key_probe(struct platform_device *pdev) { int ret,i; struct resource *res; for(i=0;i<KEYNUM_MAX;i++) { button_irqs[i].irq = platform_get_irq(pdev,i); if(button_irqs[i].irq < 0) { printk(KERN_ALERT "platform_get_irq: i = %d,irq=%d\n",i,button_irqs[i].irq); return -ENOENT; } printk(KERN_ALERT "button_irqs[i].irq is %d \n",button_irqs[i].irq); } res =platform_get_resource(pdev,IORESOURCE_MEM,0); if(res ==NULL) { dev_err(&pdev->dev,"failed to get memory region resource\n"); ret= -ENONET; } s3c2410_key_mem = request_mem_region(res->start, res->end-res->start+1,pdev->name); if(s3c2410_key_mem == NULL) { dev_err(&pdev->dev,"failed to reserve memory region\n"); ret = -ENONET; goto err_nores; } s3c2410_key_base=ioremap(res->start, res->end-res->start+1); if(s3c2410_key_base == NULL) { dev_err(&pdev->dev,"failed ioremap()\n"); ret =-ENOENT; goto err_nomap; } misc_register(&misc); printk(KERN_ALERT "probe ok and device is created\n"); return 0; err_nomap: release_resource(s3c2410_key_mem); err_nores: return ret; } static int __devexit s3c2410_key_remove(struct platform_device *dev) { platform_set_drvdata(dev,NULL); misc_deregister(&misc); iounmap(s3c2410_key_base); release_resource(s3c2410_key_mem); kfree(s3c2410_key_mem); return 0; } static struct platform_driver s3c2410_key_driver={ .probe = s3c2410_key_probe, .remove= s3c2410_key_remove, .resume=NULL, .suspend=NULL, .driver={ .name ="s3c2410-key", .owner=THIS_MODULE, }, }; static int __init dev_init(void) { //ret = misc_register(&misc); printk (DEVICE_NAME"\tinitialized\n"); return platform_driver_register(&s3c2410_key_driver); } static void __exit dev_exit(void) { platform_driver_unregister(&s3c2410_key_driver); } module_init(dev_init); module_exit(dev_exit); MODULE_LICENSE("GPL"); MODULE_AUTHOR("FriendlyARM Inc.");