adc.c

s3c44b0片上ADC的uclinux驱动

/****************************************Copyright (c)**************************************************
**                               Guangzou ZLG-MCU Development Co.,LTD.
**                                     graduate school
**                                 http://www.zlgmcu.com
**
**--------------File Info-------------------------------------------------------------------------------
** File name:           adc.c
** Last modified Date:  2005-04-21
** Last Version:        1.0
** Descriptions:        This is a Kernel module for uClinux 2.4.x .
**                      This module let uClinux 2.4.x can use adc. 
**------------------------------------------------------------------------------------------------------
** Created by:          Chenmingji
** Created date:        2005-04-21
** Version:             1.0
** Descriptions:        The original version
**
**------------------------------------------------------------------------------------------------------
** Modified by:
** Modified date:
** Version:
** Descriptions:
**

********************************************************************************************************/
#define IN_adc
#include "config.h"

/********************************************************************************************************
              function announce
********************************************************************************************************/

#if 0
static loff_t adc_llseek(struct file *filp, loff_t off, int whence);
static ssize_t adc_write(struct file *filp, const char *buf, size_t count, loff_t *f_pos);
#endif
static ssize_t adc_read(struct file *filp, char *buf, size_t count, loff_t *f_pos);

static int adc_open(struct inode *inode, struct file *filp);
static int adc_release(struct inode *inode, struct file *filp); 
static int adc_ioctl(struct inode *inode, struct file *filp, unsigned int cmd,
                     unsigned long param);
int  adc_init(void);
void adc_cleanup(void);

/********************************************************************************************************
              function announce
********************************************************************************************************/
#define MAJOR_NR major

module_init(adc_init);
module_exit(adc_cleanup);

MODULE_PARM(major, "i");

MODULE_LICENSE("Proprietary");
MODULE_DESCRIPTION("Guangzou ZLG-MCU Development Co.,LTD.\ngraduate school\nhttp://www.zlgmcu.com");
MODULE_SUPPORTED_DEVICE("uClinux2.4.x LPC2200 adc");
MODULE_AUTHOR("chenmingji");

/*********************************************************************************************************
**                  "全局和静态变量在这里定义"         
**        global variables and static variables define here
********************************************************************************************************/
static int major = ADC_MAJOR_NR;
static unsigned int adc_usage[MAX_ADC];     /* device using count */
/********************************************************************************************************/

static struct file_operations adc_fops =        /* driver info  */
{
    owner:      THIS_MODULE,
#if 0
    llseek:     adc_llseek,
    write:      adc_write,
#endif
    read:       adc_read,
    ioctl:      adc_ioctl,
    open:       adc_open,
    release:    adc_release,
};


#if 0
/*********************************************************************************************************
** Function name: adc_llseek
** Descriptions:  move read and write point
** Input: filp:   pointer of file
**        off:    ofset
**        whence: move mode
**                0: seek set
**                1: seek file' current point
**                2: seek file' end
** Output :      new point
** Created by:   Chenmingji
** Created Date: 2005-4-21
**-------------------------------------------------------------------------------------------------------
** Modified by:
** Modified Date: 
**------------------------------------------------------------------------------------------------------
********************************************************************************************************/
        static loff_t adc_llseek(struct file *filp, loff_t off, int whence)
{
    return 0;
}
#endif

/*********************************************************************************************************
** Function name: adc_read
** Descriptions:  read device
** Input: filp:   pointer of file
**        buf:    buf for save data
**        count:  size for read
**        f_pos:  *f_pos = read point
** Output : read size    
** Created by:   Chenmingji
** Created Date: 2005-4-21
**-------------------------------------------------------------------------------------------------------
** Modified by:
** Modified Date: 
**------------------------------------------------------------------------------------------------------
********************************************************************************************************/
        static ssize_t adc_read(struct file *filp, char *buf, size_t count,
                           loff_t *f_pos)
{
    unsigned long flag;
    u32 temp;
    u16 temp1;
    if (count > 2)
    {
        return -EFBIG;
    }

    if (!access_ok(VERIFY_WRITE, (void *)buf, count))
    {
        return -EFAULT;
    }

    temp = (int)filp->private_data;

    local_irq_save(flag);
    outl(inl(S3C44B0X_ADCCON)|0x01 , S3C44B0X_ADCCON);
    while(inl(S3C44B0X_ADCCON)&0x01);
    while (!(inl(S3C44B0X_ADCCON)&0x40));
    temp = inl(S3C44B0X_ADCDAT);
    local_irq_restore(flag);
    temp1 = temp & 0xffff;
    put_user(temp1, (u16 *)buf);
    return count;
}

#if 0
/*********************************************************************************************************
** Function name: adc_write
** Descriptions:  write device
** Input: filp:   pointer of file
**        buf:    buf to write data
**        count:  size for write
**        f_pos:  *f_pos = write point
** Output : write size    
** Created by:   Chenmingji
** Created Date: 2005-4-21
**-------------------------------------------------------------------------------------------------------
** Modified by:
** Modified Date: 
**------------------------------------------------------------------------------------------------------
********************************************************************************************************/
        static ssize_t adc_write(struct file *filp, const char *buf, size_t count,
                            loff_t *f_pos)
{
    return 0;
}

#endif
                
/*********************************************************************************************************
** Function name: adc_open
** Descriptions:  open device
** Input:inode:   information of device
**       filp:    pointer of file
** Output 0:      OK
**        other:  not OK
** Created by:    Chenmingji
** Created Date:  2005-4-21
**-------------------------------------------------------------------------------------------------------
** Modified by:
** Modified Date: 
**------------------------------------------------------------------------------------------------------
********************************************************************************************************/
        static int adc_open(struct inode *inode, struct file *filp)
{
    int num;
    num = MINOR(inode->i_rdev);
    if (num >= MAX_ADC)
    {
        return -ENODEV;
    }
    
    if (adc_usage[num] == 0)
    {
      filp->private_data = (void *)(num);
    }
    adc_usage[num]++;
    MOD_INC_USE_COUNT;
    printk(KERN_INFO DEVICE_NAME ": open  OK\n");
    return 0;          /* success */
} 

/*********************************************************************************************************
** Function name: adc_release
** Descriptions:  release device
** Input:inode:   information of device
**       filp:    pointer of file
** Output 0:      OK
**        other:  not OK
** Created by:    Chenmingji
** Created Date:  2005-4-21
**-------------------------------------------------------------------------------------------------------
** Modified by:
** Modified Date: 
**------------------------------------------------------------------------------------------------------
********************************************************************************************************/
        static int adc_release(struct inode *inode, struct file *filp) 
{
    int num;
    num = MINOR(inode->i_rdev);
    if (num >= MAX_ADC)
    {
        return -ENODEV;
    }
    MOD_DEC_USE_COUNT;
    adc_usage[num]--;
    return(0); 
} 

/*********************************************************************************************************
** Function name: adc_ioctl
** Descriptions:  IO control function
** Input:inode:   information of device
**       filp:    pointer of file
**       cmd:     command
**       arg:     additive parameter
** Output 0:      OK
**        other:  not OK
** Created by:    Chenmingji
** Created Date:  2005-4-21
**-------------------------------------------------------------------------------------------------------
** Modified by:
** Modified Date: 
**------------------------------------------------------------------------------------------------------
********************************************************************************************************/

        static int adc_ioctl(struct inode *inode, struct file *filp, 
                       unsigned int cmd, unsigned long arg)
{
    if (_IOC_TYPE(cmd) != ADC_IOC_MAGIC)
    {
        return -ENOTTY;
    }
    if (_IOC_NR(cmd) >= ADC_MAXNR)
    {
        return -ENOTTY;
    }

    switch(cmd)
    {
        case ADC_SET_CLKDIV:
            if(arg>255)
              {
               arg = 255;
              }
            outl(arg,S3C44B0X_ADCPSR);
            printk(KERN_INFO DEVICE_NAME ": ADC_SET_CLKDIV  OK\n");
               /* success */
            break;
        case ADC_SET_BITS:
            outl(arg&0x1C,S3C44B0X_ADCCON);
            break;
        default:
            return -ENOTTY;
            break;
    }
    return 0;
}

/*********************************************************************************************************
** Function name: adc_init
** Descriptions:  init driver
** Input:none
** Output 0:      OK
**        other:  not OK
** Created by:    Chenmingji
** Created Date:  2005-4-21
**-------------------------------------------------------------------------------------------------------
** Modified by:
** Modified Date: 
**------------------------------------------------------------------------------------------------------
********************************************************************************************************/
        int adc_init(void)
{
    int  result;
    
    result = register_chrdev(MAJOR_NR,  DEVICE_NAME,  &adc_fops); 
    if (result < 0)
    {
        printk(KERN_ERR DEVICE_NAME ": Unable to get major %d\n", MAJOR_NR );
        return(result); 
    } 

    if (MAJOR_NR == 0)
    {
        MAJOR_NR = result; /* dynamic */
    }

    outl(0, S3C44B0X_ADCCON);
    printk(KERN_INFO DEVICE_NAME ": init OK\n");
    return(0); 
}

/*********************************************************************************************************
** Function name: adc_cleanup
** Descriptions:  exit driver
** Input:none
** Output none
** Created by:    Chenmingji
** Created Date:  2005-4-21
**-------------------------------------------------------------------------------------------------------
** Modified by:
** Modified Date: 
**------------------------------------------------------------------------------------------------------
********************************************************************************************************/
        void adc_cleanup(void)
{
    outl(0, S3C44B0X_ADCCON);
    unregister_chrdev(MAJOR_NR, DEVICE_NAME);
}

/*********************************************************************************************************
**                            End Of File
********************************************************************************************************/