驱动程序如下,希望加载后SPICLK0口能产生时钟信号.
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/fs.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/gpio.h>
#include <asm/irq.h>
#include <asm/io.h>
#include <asm/uaccess.h>
#include <mach/regs-gpio.h>
#include <mach/regs-clock.h>
#include <mach/hardware.h>
#include <mach/regs-irq.h>
#include <linux/clk.h>
#include <linux/cdev.h>
#include <linux/device.h>
#include <linux/miscdevice.h>
#define DEVICE_NAME "test"
static void __iomem *base_addr;
#define myCLKCON (*(volatile unsigned long *)(base_addr+0x0c))
static int test_open(struct inode *inode,struct file *filp)
{
printk("in open function\n");
return 0;
}
static ssize_t test_write(struct file *filp,const char __user *buf,size_t count,loff_t *f_ops)
{
printk("in write function\n");
return 0;
}
static int test_close(struct inode *inode,struct file *filp)
{
printk("in close function\n");
return 0;
}
static struct file_operations test_fops = {
.owner = THIS_MODULE,
.open =test_open,
.write =test_write,
.release=test_close,
};
static struct miscdevice misc = {
.minor = MISC_DYNAMIC_MINOR,
.name = DEVICE_NAME,
.fops = &test_fops,
};
static int __init dev_init(void)
{
int ret;
s3c2410_gpio_cfgpin(S3C2410_GPE(13),S3C2410_GPE13_SPICLK0);
base_addr=ioremap(0x4c000000,64);
if(base_addr==NULL)
{
printk("Failed to remap register block\n");
return -ENOMEM;
}
else
printk("ioremap succeded\n");
//__raw_writel(__raw_readl(S3C2410_CLKCON)|S3C2410_CLKCON_SPI,S3C2410_CLKCON);
myCLKCON |= (1<<18);
ret = misc_register(&misc);
printk(DEVICE_NAME"\tinitialized\n");
return ret;
}
static void __exit dev_exit(void)
{
iounmap(base_addr);
misc_deregister(&misc);
}
module_init(dev_init);
module_exit(dev_exit);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("FriendlyARM Inc.");
