simple_attr_write
.write = simple_attr_write,
ret = simple_attr_write(file, buf, len, ppos);
EXPORT_SYMBOL_GPL(simple_attr_write);
.write = (__is_signed) ? simple_attr_write_signed : simple_attr_write, \
ssize_t simple_attr_write(struct file *file, const char __user *buf,
.write = simple_attr_write,