N32905 adc字符设备驱动

#include <linux/errno.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/input.h>
#include <linux/init.h>
#include <linux/serio.h>
#include <linux/delay.h>
#include <linux/clk.h>
#include <linux/wait.h>
#include <linux/sched.h>
#include <asm/io.h>
#include <asm/irq.h>
#include <asm/uaccess.h>
#include <linux/cdev.h>
#include <linux/miscdevice.h>
#include <mach/hardware.h>
#include <mach/irqs.h>
#include <mach/w55fa93_reg.h>
#include <linux/input.h>
#include <linux/clk.h>

#define DEVICE_NAME "adc"
#define outp32(addr, value)     writel(value, addr)
#define inp32(addr)             readl(addr)


static void __iomem *base_addr;

#define ADC_INPUT(x)        ((x) << 9)


#define SET_NORMAL_AIN2_WI  do{\
                                outl( (ADC_CON_ADC_EN | ADC_CONV | ADC_INT | (2<<9)), \
                                REG_ADC_CON);\
                            }while(0)

#define SET_NORMAL_AIN2_WI_WR \
                            while(  (inl(REG_ADC_CON) & ADC_INT) != ADC_INT )


#define SET_NORMAL_AIN0_WI  do{\
                                outl( (ADC_CON_ADC_EN | ADC_CONV | ADC_INT | (0<<9)), \
                                REG_ADC_CON);\
                            }while(0)

#define SET_NORMAL_AIN0_WI_WR \
                            while(  (inl(REG_ADC_CON) & ADC_INT) != ADC_INT )


static ssize_t w55fa93_adc_read(struct file *filp, char *buffer, size_t count, loff_t *ppos)
{
    unsigned int adc_data = -1;

    SET_NORMAL_AIN2_WI;
    SET_NORMAL_AIN2_WI_WR;

    adc_data = inl(REG_ADC_XDATA);

//    printk("adc_data=%d\n", adc_data);
    if (adc_data != -1)
    {
        copy_to_user(buffer, &adc_data, sizeof(adc_data));
    }
    return 0;
}

static int w55fa93_adc_open(struct inode *inode, struct file *filp)
{
    printk( "adc opened\n");
    outp32(REG_APBIPRST, inp32(REG_APBIPRST) | ADCRST);
    outp32(REG_APBIPRST,  inp32(REG_APBIPRST) & ~ADCRST);
    return 0;
}

static int w55fa93_adc_release(struct inode *inode, struct file *filp)
{
    printk( "adc closed\n");
    return 0;
}
static struct file_operations dev_fops = {
    owner:  THIS_MODULE,
    open:   w55fa93_adc_open,
    read:   w55fa93_adc_read,
    release:    w55fa93_adc_release,
};

static struct miscdevice misc = {
    .minor = MISC_DYNAMIC_MINOR,
    .name = DEVICE_NAME,
    .fops = &dev_fops,
};

static int __init dev_init(void)
{
    int ret;
    struct clk *clk;

    base_addr=ioremap(W55FA93_PA_ADC, 0x20);
    if (base_addr == NULL) {
        printk(KERN_ERR "Failed to remap register block\n");
        return -ENOMEM;
    }
    printk("base_addr:0x%lx\n", (unsigned long)base_addr);

    clk = clk_get(NULL, "ADC");
    clk_enable(clk);

    ret = misc_register(&misc);

    printk (DEVICE_NAME"\tinitialized\n");
    return ret;
}

static void __exit dev_exit(void)
{
    struct clk *clk;
    clk = clk_get(NULL, "ADC");
    clk_disable(clk);

    iounmap(base_addr);

    printk (DEVICE_NAME"\texit!\n");
    misc_deregister(&misc);
}

module_init(dev_init);
module_exit(dev_exit);

MODULE_AUTHOR("zpzyf");
MODULE_DESCRIPTION("w55fa93 adc char driver");
MODULE_LICENSE("GPL");