字元裝置之Buttons-中斷共用（1）

buttons.c

#include <linux/fs.h> #include <linux/module.h> #include <linux/errno.h> #include <linux/kernel.h> #include <linux/init.h> #include <linux/cdev.h> #include <linux/ioport.h> #include <linux/pci.h> #include <asm/uaccess.h> #include <asm/io.h> #include <asm/irq.h> #include <linux/interrupt.h> #include <asm/mach/irq.h> static int major = 0; static struct class *cls; /* gpecon 0x56000040 */ /* gpfcon 0x56000050 */ /* gpgcon 0x56000060 */ static volatile unsigned long *gpecon; static volatile unsigned long *gpedat; static volatile unsigned long *gpfcon; static volatile unsigned long *gpfdat; static volatile unsigned long *gpgcon; static volatile unsigned long *gpgdat; static irqreturn_t buttons_irq(int irq, void *dev_id) {  //char *str = (char *)dev_id;  printk("irq = %d, dev_id = %d\n", irq, (int)dev_id);    return IRQ_HANDLED;  } static irqreturn_t buttons_irq2(int irq, void *dev_id) {  //char *str = (char *)dev_id;  printk("buttons_irq2 **************\n");    return IRQ_HANDLED;  }   int buttons_open(struct inode *inode, struct file *file) {    return 0; } ssize_t buttons_read(struct file *inode, char __user *buf, size_t size, loff_t *offset) {  return 0; } static const struct file_operations buttons_fops = {  .owner = THIS_MODULE,  .read = buttons_read,  .open = buttons_open  /* 設定引腳,申請資源 */ }; char *id = "K1"; int buttons_init(void) {  major = register_chrdev(0, "buttons", &buttons_fops);  /* sysfs */  cls = class_create(THIS_MODULE, "buttons_class");  class_device_create(cls, NULL, MKDEV(major, 0), NULL, "buttons");  gpecon = ioremap(0x56000040, 4096);  gpedat = gpecon + 1;  gpfcon = gpecon + 4;  gpfdat = gpfcon + 1;  gpgcon = gpecon + 8;  gpgdat = gpgcon + 1;  /* 註冊中斷 共用中斷號*/   request_irq(IRQ_EINT0, buttons_irq,              IRQF_SHARED | IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING,              "K10_irq", 'a');  request_irq(IRQ_EINT0, buttons_irq2,              IRQF_SHARED | IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING,              "K10_irq_other", 'b');  /* 設定GPIO為中斷引腳   * 設定觸發方式   * 使能中斷   */  /* 設定KSCAN0(GPE11)為輸出引腳,輸出0 */  *gpecon &= ~(0x3 << 22);  *gpecon |= (1 << 22);  *gpedat &= ~(1<<11);    return 0; } void buttons_exit(void) {  unregister_chrdev(major, "buttons");  class_device_destroy(cls, MKDEV(major, 0));  class_destroy(cls);  iounmap(gpecon);  free_irq(IRQ_EINT0, 'a');  free_irq(IRQ_EINT0, 'b');   } module_init(buttons_init); module_exit(buttons_exit); MODULE_LICENSE("GPL");

測試：

#insmod buttons.ko

（按下K10後，兩個服務程式都被掉用。如果是不同的外部裝置共用中斷號，那麼由硬體自動檢測是哪個硬體所發的中斷）

irq = 16, dev_id = 97
buttons_irq2 **************
irq = 16, dev_id = 97
buttons_irq2 **************