目前正在学习设备树知识，在中断一节中，下载内核，dtb到jz2440开发板，按键S2,S3只有在松开的时候有返回值，按下的时候没有返回值，S4,S5正常。下载韦老师云盘上的代码试验了也一样，是内核中那个地方没该对吗？谢谢！
把 app 和 驱动贴出来看看；
驱动
#include <linux/module.h>
#include <linux/sched.h>
#include <linux/kernel.h>
#include <linux/fs.h>
#include <linux/init.h>
#include <linux/delay.h>
#include <linux/irq.h>
#include <asm/uaccess.h>
#include <asm/irq.h>
#include <asm/io.h>
#include <linux/device.h>
#include <linux/interrupt.h>
#include <linux/poll.h>
#include <mach/regs-gpio.h>
#include <mach/gpio-samsung.h>
#include <plat/gpio-cfg.h>
#include <linux/of_gpio.h>
#include <linux/gpio.h>
#include <linux/of.h>
#include <linux/of_device.h>
#include <linux/of_platform.h>
#include <linux/platform_device.h>
static struct class *sixthdrv_class;
static struct device *sixthdrv_class_dev;
volatile unsigned long *gpfcon;
volatile unsigned long *gpfdat;
volatile unsigned long *gpgcon;
volatile unsigned long *gpgdat;
static struct timer_list buttons_timer;
static DECLARE_WAIT_QUEUE_HEAD(button_waitq);
/* 中断事件标志, 中断服务程序将它置1，sixth_drv_read将它清0 */
static volatile int ev_press = 0;
struct pin_desc{
unsigned int pin;
unsigned int key_val;
int irq;
};
struct pin_desc pins_desc[4] = {{0, 0x01},{0, 0x02},{0, 0x03},{0, 0x04},};
/* 键值: 按下时, 0x01, 0x02, 0x03, 0x04 /
/ 键值: 松开时, 0x81, 0x82, 0x83, 0x84 */
static unsigned char key_val;
static struct pin_desc *irq_pd;
/* 确定按键值 */
static irqreturn_t buttons_irq(int irq, void dev_id)
{
/ 10ms后启动定时器 */
irq_pd = (struct pin_desc *)dev_id;
mod_timer(&buttons_timer, jiffies+HZ/100);
return IRQ_RETVAL(IRQ_HANDLED);
}
static int sixth_drv_open(struct inode *inode, struct file *file)
{
return 0;
}
ssize_t sixth_drv_read(struct file *file, char __user *buf, size_t size, loff_t ppos)
{
/ 如果没有按键动作, 休眠 */
wait_event_interruptible(button_waitq, ev_press);
/* 如果有按键动作, 返回键值 */
copy_to_user(buf, &key_val, 1);
ev_press = 0;
return 1;
}
int sixth_drv_close(struct inode *inode, struct file *file)
{
int i;
for (i = 0; i < sizeof(pins_desc)/sizeof(pins_desc[0]); i++) {
free_irq(pins_desc[i].irq, &pins_desc[i]);
}
return 0;
}
static struct file_operations sixth_drv_fops = {
.owner = THIS_MODULE, /* 这是一个宏，推向编译模块时自动创建的__this_module变量 */
.open = sixth_drv_open,
.read = sixth_drv_read,
.release = sixth_drv_close,
};
int major;
static void buttons_timer_function(struct timer_list *t)
{
struct pin_desc * pindesc = irq_pd;
unsigned int pinval;
if (!pindesc)
return;
pinval = gpio_get_value(pindesc->pin);
if (pinval)
{ /* 松开 */
key_val = 0x80 | pindesc->key_val;
}
else
{ /* 按下 */
key_val = pindesc->key_val;
}
ev_press = 1; /* 表示中断发生了 */
wake_up_interruptible(&button_waitq); /* 唤醒休眠的进程 */
}
static int sixth_drv_init(void)
{
timer_setup(&buttons_timer, buttons_timer_function, 0);
add_timer(&buttons_timer);
major = register_chrdev(0, "sixth_drv",&sixth_drv_fops);
sixthdrv_class = class_create(THIS_MODULE, "sixth_drv");
/* 为了让mdev根据这些信息来创建设备节点 */
sixthdrv_class_dev = device_create(sixthdrv_class, NULL, MKDEV(major, 0), NULL, "buttons"); /* /dev/buttons */
gpfcon = (volatile unsigned long *)ioremap(0x56000050, 16);
gpfdat = gpfcon + 1;
gpgcon = (volatile unsigned long *)ioremap(0x56000060, 16);
gpgdat = gpgcon + 1;
return 0;
}
static void sixth_drv_exit(void)
{
del_timer(&buttons_timer);
unregister_chrdev(major, “sixth_drv”);
device_destroy(sixthdrv_class, MKDEV(major, 0));
class_destroy(sixthdrv_class);
iounmap(gpfcon);
iounmap(gpgcon);
}
static int buttons_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
struct device_node *dp_node = dev->of_node;
struct resource *res;
int i;
int ret;
for (i = 0; i < sizeof(pins_desc)/sizeof(pins_desc[0]); i++)
{
/* 根据platform_device的资源进行获得中断号,触发类型 */
res = platform_get_resource(pdev, IORESOURCE_IRQ, i);
if (res) {
pins_desc[i].irq = res->start;
printk("get irq %d\n", pins_desc[i].irq);
}
else {
printk("can not get irq res for eint0\n");
return -1;
}
pins_desc[i].pin = of_get_named_gpio(dp_node, "eint-pins", i);
printk("pins_desc[%d].pin = %d\n", i, pins_desc[i].pin);
}
/* 配置GPF0,2为输入引脚 配置GPG3,11为输入引脚 */
ret = request_irq(pins_desc[0].irq, buttons_irq, 0, "S2", &pins_desc[0]);
if (ret)
{
printk("reqeust_irq %d for EINT0 err : %d!\n", pins_desc[0].irq, ret);
}
ret = request_irq(pins_desc[1].irq, buttons_irq, 0, "S3", &pins_desc[1]);
if (ret)
{
printk("reqeust_irq for EINT2 err : %d!\n", ret);
}
ret = request_irq(pins_desc[2].irq, buttons_irq, 0, "S4", &pins_desc[2]);
if (ret)
{
printk("reqeust_irq for EINT11 err : %d!\n", ret);
}
ret = request_irq(pins_desc[3].irq, buttons_irq, 0, "S5", &pins_desc[3]);
if (ret)
{
printk("reqeust_irq for EINT19 err : %d!\n", ret);
}
return sixth_drv_init();
}
static int buttons_remove(struct platform_device *pdev)
{
sixth_drv_exit();
return 0;
}
static const struct of_device_id of_match_buttons[] = {
{ .compatible = “jz2440_button”, .data = NULL },
{ /* sentinel */ }
};
struct platform_driver buttons_drv = {
.probe = buttons_probe,
.remove = buttons_remove,
.driver = {
.name = “jz2440_button”,
.of_match_table = of_match_buttons, /* 能支持哪些来自于dts的platform_device */
}
};
static int buttons_init(void)
{
platform_driver_register(&buttons_drv);
return 0;
}
static void buttons_exit(void)
{
platform_driver_unregister(&buttons_drv);
}
module_init(buttons_init);
module_exit(buttons_exit);
MODULE_LICENSE(“GPL”);
app
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <stdio.h>
#include <poll.h>
#include <signal.h>
#include <sys/types.h>
#include <unistd.h>
#include <fcntl.h>
/* sixthdrvtest
*/
int fd;
int main(int argc, char **argv)
{
unsigned char key_val;
int ret;
fd = open("/dev/buttons", O_RDWR);
if (fd < 0)
{
printf("can't open!\n");
return -1;
}
while (1)
{
ret = read(fd, &key_val, 1);
printf("key_val: 0x%x, ret = %d\n", key_val, ret);
}
return 0;
}
谢谢。
尝试把第三个参数改为:
IRQ_TYPE_EDGE_BOTH = (IRQ_TYPE_EDGE_FALLING | IRQ_TYPE_EDGE_RISING),
结果还是一样。
那直接用韦老师的代码来尝试，包括 dts、驱动、测试代码；
如果还是不行，@ 韦老师求助好了；
如果可以，用 Beyond Compare 4 软件来比较代码，查找差异部分；