为什么我这样点灯点不起来？（）

[林鼎鼎]

芯片手册RK3328
原理图

#include <linux/init.h>
#include <linux/module.h>
#include <asm/io.h>
#include <linux/ioport.h>

#define GPIO2_BASE	0xFF230000
#define GPIO2_MEM_SIZE	0x00010000
#define GPIO2_DIR	(volatile unsigned long *)ioremap(GPIO2_BASE + 4, 4)
#define GPIO2_OUT	(volatile unsigned long *)ioremap(GPIO2_BASE + 0, 4)
MODULE_LICENSE("Dual BSD/GPL");
static int hello_init(void)
{
	unsigned int res;
	unsigned int set;

	printk(KERN_INFO "Hello, world\n");
	//request_mem_region(GPIO2_BASE, GPIO2_MEM_SIZE, "GPIO2_LED");

	res = __raw_readl(GPIO2_DIR);
	printk(KERN_INFO "Before set GPIO2_DIR value :%d\n", res);
	res = __raw_readl(GPIO2_OUT);
	printk(KERN_INFO "Before set GPIO2_OUT value :%d\n", res);

	//GPIO2_B7 output
	set = __raw_readl(GPIO2_DIR);
	set |= ~(1 << 23);
	set = 0;	//全out
	__raw_writel(set, GPIO2_DIR);

	//GPIO2_B7 = 1
	set = __raw_readl(GPIO2_OUT);
	set |= (1 << 23);
	set = 0xffffffff;	//全高电平
	__raw_writel(set, GPIO2_OUT);

	res = __raw_readl(GPIO2_DIR);
	printk(KERN_INFO "After set GPIO2_DIR value :%d\n", res);
	res = __raw_readl(GPIO2_OUT);
	printk(KERN_INFO "After set GPIO2_OUT value :%d\n", res);

//ERR:
	return 0;
}
static void hello_exit(void)
{
	printk(KERN_INFO "Goodbye, cruel world\n");
	//release_mem_region(GPIO2_BASE, GPIO2_MEM_SIZE);
}
module_init(hello_init);
module_exit(hello_exit);

这样写有问题吗？（实际上灯没被点亮）