static ssize_t motion_det_ctl_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
return sprintf(buf, "%d\n", func_status);
}
static ssize_t motion_det_ctl_store(struct device *dev,struct device_attribute *attr,
const char *buf, size_t size)
{
char *after;
func_status = simple_strtoul(buf, &after, 10);
return size;
}
static DEVICE_ATTR(motion, 0777,
motion_det_ctl_show, motion_det_ctl_store);
static struct attribute *motion_det_attributes[] = {
&dev_attr_motion.attr,
NULL
};
static struct attribute_group motion_det_attribute_group = {
.name = "motion_det",
.attrs = motion_det_attributes
};
static struct miscdevice motion_det_dev = {
.minor = MISC_DYNAMIC_MINOR,
.name = "motion_det_class",
};
1 应用程序执行read的时候会调用motion_det_ctl_show 然后关掉文件描述符 ，这个是读取时正常的 2 应用打开文件 循环read 读到的一直是0 怎么解释？
