s3c2410_adc.c

s3c2410ADC驱动程序

# include <linux/config.h>
# include <linux/module.h> 
# include <linux/kernel.h> 
# include <linux/init.h> 
# include <linux/device.h>
# include <linux/delay.h> 
# include <linux/devfs_fs_kernel.h>

# include <asm/io.h>
# include <asm/hardware.h> 
# include <asm/arch/regs-gpio.h> 
# include <asm/uaccess.h> 
# include <asm/delay.h>     
# include <asm-arm/arch-s3c2410/regs-adc.h>
# include <asm/hardware/clock.h>

#define DEVICE_NAME "adc" 
#define ADC_MAJOR 223 
int i;
//#define base_addr 0x58000000
#define START_ADC {S3C2410_ADCCON_PRSCEN | S3C2410_ADCCON_PRSCVL(49) | S3C2410_ADCCON_SELMUX(i) | S3C2410_ADCCON_READ_START; }
     
MODULE_AUTHOR("Luofuchong"); 
MODULE_LICENSE("Dual BSD/GPL"); 
MODULE_ALIAS("led"); 
     
static void __iomem *base_addr;
/*static unsigned long led_table [] = { 
S3C2410_GPG12, 
S3C2410_GPG13, 
S3C2410_GPB9, 
S3C2410_GPB10, 
            S3C2410_GPG12_OUTP, 
            S3C2410_GPG13_OUTP, 
            S3C2410_GPB9_OUTP, 
            S3C2410_GPB10_OUTP, 
    };
*/ 
     
     
static int s3c2410_adc_ioctl(struct inode *inode, struct file *file, unsigned int channel, unsigned long arg) {
	long int tmp=100;
	int dianya;
	i=channel;
	writel(START_ADC, base_addr+S3C2410_ADCCON); 
	tmp = (readl( base_addr + S3C2410_ADCDAT0) & 0x3ff);
	dianya = tmp * 3300 /1024;
//	dianya = base_addr;
/*    switch(cmd) { 
    case 0: 
    case 1: 
    if (arg > 3) { 
    return -EINVAL; 
    } 
    s3c2410_gpio_setpin(led_table[arg],!cmd); 
    break; 
            default: 
    return -EINVAL; 
    }
*/ 
	return dianya; 
} 
     
static struct file_operations s3c2410_adc_fops = { 
	.owner = THIS_MODULE, 
	.ioctl = s3c2410_adc_ioctl, 
}; 
     
static struct class *led_class; 

static struct clk   *adc_clock;
     
static int __init s3c2410_adc_init(void) { 
	int err = 0; 

	if(register_chrdev(ADC_MAJOR,"adc",&s3c2410_adc_fops)){ 
		printk("led driver:Unable to register driver\n"); 
		return -ENODEV; 
	} 
	adc_clock = clk_get(NULL, "adc");
	if (!adc_clock) {
		printk(KERN_ERR "failed to get adc clock source\n");
		return -ENOENT;
	}
	clk_use(adc_clock);
	clk_enable(adc_clock);

	base_addr=ioremap(S3C2410_PA_ADC,0x20);
	if (base_addr == NULL) {
		printk(KERN_ERR "Failed to remap register block\n");
		return -ENOMEM;
	}
	led_class = class_create(THIS_MODULE, "adc"); 
	if(IS_ERR(led_class)){ 
		err = PTR_ERR(led_class); 
		goto out_chrdev; 
	} 
	class_device_create(led_class,MKDEV(ADC_MAJOR, 0),NULL,"adc"); 
         
	err = devfs_mk_cdev(MKDEV(ADC_MAJOR,0), 
                            S_IFCHR | S_IRUGO | S_IWUSR,"adc"); 
	if(err) 
	goto out_class; 
     
/*              for(i=0;i<4;i++){ 
                      s3c2410_gpio_cfgpin(led_table[i],led_table[i+4]); 
                      s3c2410_gpio_setpin(led_table[i],1); 
              } 
*/
	printk("adc driver initialized\n"); 
	goto out; 
     
	out_class: 
		class_device_destroy(led_class,MKDEV(ADC_MAJOR, 0)); 
		class_destroy(led_class); 
	out_chrdev: 
		unregister_chrdev(ADC_MAJOR, "adc"); 
	out: 
        	return err; 
} 
     
static void __exit s3c2410_adc_exit(void) { 
	class_device_destroy(led_class,MKDEV(ADC_MAJOR,0)); 
	class_destroy(led_class); 
	unregister_chrdev(ADC_MAJOR,"adc"); 
	devfs_remove("adc"); 
	printk("adc driver removed\n"); 
} 
     
module_init(s3c2410_adc_init);
module_exit(s3c2410_adc_exit);