linux led驱动程序 s5pc100

#include <linux/module.h> #include <linux/kernel.h> #include <linux/init.h> #include <linux/fs.h> #include <linux/cdev.h> #include <linux/sched.h> #include <linux/interrupt.h> #include <linux/irq.h> #include <linux/slab.h> #include <asm/uaccess.h> #include <asm/io.h> //#include <mach/irqs.h> MODULE_LICENSE("Dual BSD/GPL"); MODULE_AUTHOR("farsight"); #define GPH0CON 0xe0300c00 static int key_major = 250; static int key_minor = 0; struct key_device { int keyval; struct cdev cdev; struct semaphore sem; wait_queue_head_t rwait; } key_device; void *gph0con; static int s5pc100_key_open(struct inode *inode, struct file *filp) { struct key_device *dev = container_of(inode->i_cdev, struct key_device, cdev); filp->private_data = dev; printk("s5pc100_key is opened\n"); return 0; } static int s5pc100_key_release(struct inode *inode, struct file *filp) { printk("s5pc100_key is closed\n"); return 0; } static int s5pc100_key_read(struct file *filp, char __user *buf, size_t size, loff_t *off) { struct key_device *dev = filp->private_data; if (down_interruptible(&dev->sem)) return -ERESTARTSYS; while (dev->keyval == 0) { up(&dev->sem); if (filp->f_flags & O_NONBLOCK) return -EAGAIN; if (wait_event_interruptible(dev->rwait, dev->keyval != 0)) return -ERESTARTSYS; if (down_interruptible(&dev->sem)) return -ERESTARTSYS; } if (copy_to_user(buf, &dev->keyval, sizeof(int))) { up(&dev->sem); return -EFAULT; } dev->keyval = 0; up(&dev->sem); return sizeof(int); } static struct file_operations s5pc100_key_ops = { .owner = THIS_MODULE, .open = s5pc100_key_open, .release = s5pc100_key_release, .read = s5pc100_key_read, }; static irqreturn_t handler(int irqno, void *dev_id) { static long old_jiffies = 0; if (jiffies - old_jiffies < 20) return IRQ_HANDLED; old_jiffies = jiffies; printk("irq: interrupt %d\n", irqno); switch (irqno) { case IRQ_EINT(1) : key_device.keyval = 1; break; case IRQ_EINT(2) : key_device.keyval = 2; break; case IRQ_EINT(3) : key_device.keyval = 3; break; case IRQ_EINT(4) : key_device.keyval = 4; break; case IRQ_EINT(6) : key_device.keyval = 5; break; case IRQ_EINT(7) : key_device.keyval = 6; break; } wake_up(&key_device.rwait); return IRQ_HANDLED; } static int key_request_irq(void) { int result; result = request_irq(IRQ_EINT(1), handler, IRQF_DISABLED|IRQF_TRIGGER_FALLING, "key_1", NULL); if (result) { printk("key: request irq %d failed!\n", IRQ_EINT(1)); return result; } result = request_irq(IRQ_EINT(2), handler, IRQF_DISABLED|IRQF_TRIGGER_FALLING, "key_2", NULL); if (result) { printk("key: request irq %d failed!\n", IRQ_EINT(2)); goto _error_irq1; } result = request_irq(IRQ_EINT(3), handler, IRQF_DISABLED|IRQF_TRIGGER_FALLING, "key_3", NULL); if (result) { printk("key: request irq %d failed!\n", IRQ_EINT(3)); goto _error_irq2; } result = request_irq(IRQ_EINT(4), handler, IRQF_DISABLED|IRQF_TRIGGER_FALLING, "key_4", NULL); if (result) { printk("key: request irq %d failed!\n", IRQ_EINT(4)); goto _error_irq3; } result = request_irq(IRQ_EINT(6), handler, IRQF_DISABLED|IRQF_TRIGGER_FALLING, "key_6", NULL); if (result) { printk("key: request irq %d failed!\n", IRQ_EINT(6)); goto _error_irq4; } result = request_irq(IRQ_EINT(7), handler, IRQF_DISABLED|IRQF_TRIGGER_FALLING, "key_7", NULL); if (result) { printk("key: request irq %d failed!\n", IRQ_EINT(7)); goto _error_irq6; } return 0; _error_irq6 : free_irq(IRQ_EINT(6), NULL); _error_irq4 : free_irq(IRQ_EINT(4), NULL); _error_irq3 : free_irq(IRQ_EINT(3), NULL); _error_irq2 : free_irq(IRQ_EINT(2), NULL); _error_irq1 : free_irq(IRQ_EINT(1), NULL); return result; } static void init_key(void) { gph0con = ioremap(GPH0CON, 4); writel((readl(gph0con) & ~0xff0ffff0) | (0x22022220), gph0con); } static void key_free_irq(void) { free_irq(IRQ_EINT(1), NULL); free_irq(IRQ_EINT(2), NULL); free_irq(IRQ_EINT(3), NULL); free_irq(IRQ_EINT(4), NULL); free_irq(IRQ_EINT(6), NULL); free_irq(IRQ_EINT(7), NULL); } static int key_setup_cdev(struct cdev *cdev, struct file_operations *ops) { int result; dev_t devno = MKDEV(key_major, key_minor); cdev_init(cdev, ops); cdev->owner = THIS_MODULE; result = cdev_add(cdev, devno, 1); if (result) { printk("key: fail to add cdev\n"); return result; } return 0; } static int __init s5pc100_key_init(void) { int result; dev_t devno = MKDEV(key_major, key_minor); result = register_chrdev_region(devno, 1, "s5pc100_key"); if (result) { printk("key: unable to get major %d\n", key_major); return result; } result = key_setup_cdev(&key_device.cdev, &s5pc100_key_ops); if (result) goto _error1; result = key_request_irq(); if (result) goto _error2; init_key(); key_device.keyval = 0; init_MUTEX(&key_device.sem); // can used in kernel which version is no more than 2.6.35 init_waitqueue_head(&key_device.rwait); printk("key : init_module\n"); return 0; _error2: cdev_del(&key_device.cdev); _error1: unregister_chrdev_region(devno, 1); return result; } static void __exit s5pc100_key_exit(void) { dev_t devno = MKDEV(key_major, key_minor); key_free_irq(); cdev_del(&key_device.cdev); unregister_chrdev_region(devno, 1); printk("key: cleanup_module!\n"); } module_init(s5pc100_key_init); module_exit(s5pc100_key_exit);