s3c2410_spi0.c

ARM s3c2410 linux2.6下的spi驱动.

#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/ioport.h>
#include <linux/miscdevice.h> 
#include <linux/sched.h> 
#include <linux/delay.h> 
#include <linux/poll.h> 
#include <linux/spinlock.h> 
#include <linux/delay.h> 
#include <linux/wait.h>

#include <linux/device.h> 
#include <linux/devfs_fs_kernel.h> 
#include <linux/types.h> 
#include <linux/cdev.h> 
#include <linux/errno.h> 
#include <asm/uaccess.h> 
#include <asm/hardware.h>
#include <asm/io.h>
#include <asm/arch/regs-mem.h>
#include <asm/arch/regs-gpio.h>
#include <asm/arch/regs-spi.h>


#define DEVICE_NAME		"S3C2410_SPI0"

	static int spi_major = 0;
	static unsigned long *spi_clkcon;
	static unsigned long *spi_gpgcon;
	static unsigned long *spi_gpecon;	//GPG Part define
	static unsigned long *spi_gpedat;
	static unsigned long *spi_gpeup;
	static unsigned long *spi_gpgdat;
	static unsigned long *spi_gpgup;
	static unsigned long *spi_spcon0;	//SPI Part define
	static unsigned long *spi_spsta0;
	static unsigned long *spi_sppin0;
	static unsigned long *spi_sppre0;
	static unsigned long *spi_sptdat0;
	static unsigned long *spi_sprdat0;
	
	
void spi_Initial(void)
{	
	*spi_clkcon |= (1<<18);
	*spi_sppre0=0x0f;//SPI Baud Rate Prescaler Register,Baud Rate=PCLK/2/(Prescaler value+1)
	*spi_spcon0=(0<<6)|(0<<5)|(1<<4)|(1<<3)|(0<<2)|(0<<1)|(0<<0);
	//polling,en-sck,slave,low,format A,nomal
	*spi_sppin0=(0<<2)|(1<<1)|(0<<0);
	//Multi Master error detect disable,reserved,release
	*spi_gpecon=(*spi_gpecon&(~((3<<22)|(3<<24)|(3<<26)))) | (2<<22) | (2<<24) | (2<<26);
	*spi_gpgcon=(3<<4);
	
}	

static int spi_open(struct inode *inode,struct file *filp)
{
	spi_Initial();
	return 0;
}

static ssize_t spi_write(struct file *filp,const char *buf,size_t count,loff_t *f_ops)
{	
	int i;  
	char *tmp;
	tmp = kmalloc(count,GFP_KERNEL);
	copy_from_user(tmp,buf,count);
	for(i = 0; i< count; i++)
	{
		while((*spi_spsta0&0x01)==0);
		*spi_sptdat0 = tmp[i];
	}
	kfree(tmp);
	return 1;
}

static int spi_reay_wait(unsigned int delay)
{
	unsigned long jiffies_new;
	jiffies_new = jiffies + delay;	
	while((*spi_spsta0&0x01)==0)
	{
		if(jiffies > jiffies_new)
			return 0;
	}
	return 1;
}

static ssize_t spi_read(struct file *filp, char *buf,size_t count,loff_t *f_ops)
{	
	int i;
	char *tmp;
	
	tmp = kmalloc(count,GFP_KERNEL);
	
	
	for(i=0; i<count; i++)
	{
		if(spi_reay_wait(HZ/10))
		{
			tmp[i] = *spi_sprdat0;	
		}
		else
		{
			i++;
			break;
		}
	}

	copy_to_user(buf,tmp,i);
	return (i);
}

static int spi_ioctl(struct inode *inode, struct file *file, unsigned int cmd, unsigned long arg)
{
	*spi_sppre0 = (unsigned long)cmd;
	return 0;
}

static struct file_operations spi_fops = {
	.owner		= THIS_MODULE,
	.open			= spi_open,
	.write		= spi_write,
	.read			= spi_read,
	.ioctl		= spi_ioctl,
};
static int __init spi_init(void)
{
	int ret;
	spi_gpedat = ioremap (0x56000044,4);
	spi_gpeup =  ioremap (0x56000048,4);	
	spi_clkcon = ioremap (0x4C00000C,4);
	spi_gpecon = ioremap (0x56000040,4);	
	spi_gpgcon = ioremap (0x56000060,4);
	spi_gpgdat = ioremap (0x56000064,4);
	spi_gpgup =  ioremap (0x56000068,4);
	spi_spcon0 = ioremap(0x59000000,4);
	spi_spsta0 = ioremap(0x59000004,4);
	spi_sppin0=  ioremap(0x59000008,4);
	spi_sppre0 = ioremap(0x5900000c,4);
	spi_sptdat0 =ioremap(0x59000010,4);
	spi_sprdat0 =ioremap(0x59000014,4);
	
	ret = register_chrdev(0,DEVICE_NAME,&spi_fops);
    if(ret < 0) 
	{
		printk("cpld_io: can't get major number\n");
       	return ret;
	}
	spi_major = ret;
	
#ifdef CONFIG_DEVFS_FS   
    ret = devfs_mk_cdev(MKDEV(spi_major,0),  S_IFCHR | S_IRUGO | S_IWUSR,DEVICE_NAME);
	if(ret)
	{
		unregister_chrdev(spi_major,DEVICE_NAME); 
		printk("s3c2410-spi0: can't make char device fo devfs\n");
		return ret;
	}
#endif
	
	                                                                                                            
	printk("s3c2410-spi0 driver initial\n"); 
	return 0;
}


static void __exit spi_exit(void)
{
#ifdef CONFIG_DEVFS_FS
	devfs_remove(DEVICE_NAME);
#endif  
	unregister_chrdev(spi_major,DEVICE_NAME); 
    printk("s3c2410-spi driver removed\n"); 
}
MODULE_ALIAS("S3C2410_SPI0"); 
MODULE_DESCRIPTION("SPI0_driver for S3C2410");
MODULE_AUTHOR("FENG");
MODULE_LICENSE("GPL");
module_init(spi_init);
module_exit(spi_exit);