时实时钟RTC驱动移植（PCF5863）

由于产品板中没有PCF8563驱动，需要写驱动程序。

PCF8563驱动其实并不多，主要就是两个函数。

pcf8563_get_datetime 和 pcf8563_set_datetime。 写完这两个也是基本完成了。

参考rtc_pcf8563.c rtc_pcf8563.rar   代码改写。

改写后部分内容如下：

pcf8563.h内容：

#ifndef _PCF8563_H
#define _PCF8563_H



#define RTC_RD_TIME 0
#define RTC_SET_TIME 1


typedef struct
{
    int tm_sec;
    int tm_min;
    int tm_hour;
    int tm_mday;
    int tm_wday;
    int tm_mon;
    int tm_year;
}rtc_time_t;

#endif

pcf8563.c内容：

主要也就是pcf8563_get_datetime 和 pcf8563_set_datetime两个函数和一个控制调用函数（pcf8563_rtc_ioctl），现就列这几个吧，其他就不贴出来了。

一些宏定义:

#define PCF8563_REG_ST1 0x00 /* status */
#define PCF8563_REG_ST2 0x01

#define PCF8563_REG_SC 0x02 /* datetime */
#define PCF8563_REG_MN 0x03
#define PCF8563_REG_HR 0x04
#define PCF8563_REG_DM 0x05
#define PCF8563_REG_DW 0x06
#define PCF8563_REG_MO 0x07
#define PCF8563_REG_YR 0x08

#define PCF8563_REG_AMN 0x09 /* alarm */
#define PCF8563_REG_AHR 0x0A
#define PCF8563_REG_ADM 0x0B
#define PCF8563_REG_ADW 0x0C

#define PCF8563_REG_CLKO 0x0D /* clock out */
#define PCF8563_REG_TMRC 0x0E /* timer control */
#define PCF8563_REG_TMR 0x0F /* timer */

#define PCF8563_SC_LV 0x80 /* low voltage */
#define PCF8563_MO_C 0x80 /* century */

#define I2C_PCF8563 0xA2

static inline

int bin2bcd (int x)

{

return (x%10) | ((x/10) << 4);

}

static inline

int bcd2bin (int x)

{

return (x >> 4) * 10 + (x & 0x0f);

}

读RTC pcf8563数据：

static int pcf8563_get_datetime(int i2c_devaddress , rtc_time_t *tm)
{
        unsigned char buf[PCF8563_REG_YR+1] = { PCF8563_REG_ST1 };
        /* status */
        //buf[PCF8563_REG_ST1] = hi_i2c_read(i2c_devaddress, PCF8563_REG_ST1);
        //buf[PCF8563_REG_ST2] = hi_i2c_read(i2c_devaddress, PCF8563_REG_ST2);

        /* datetime */
        buf[PCF8563_REG_SC] = hi_i2c_read(i2c_devaddress, PCF8563_REG_SC);
        buf[PCF8563_REG_MN] = hi_i2c_read(i2c_devaddress, PCF8563_REG_MN);
        buf[PCF8563_REG_HR] = hi_i2c_read(i2c_devaddress, PCF8563_REG_HR);
        buf[PCF8563_REG_DM] = hi_i2c_read(i2c_devaddress, PCF8563_REG_DM);
        buf[PCF8563_REG_DW] = hi_i2c_read(i2c_devaddress, PCF8563_REG_DW);
        buf[PCF8563_REG_MO] = hi_i2c_read(i2c_devaddress, PCF8563_REG_MO);
        buf[PCF8563_REG_YR] = hi_i2c_read(i2c_devaddress, PCF8563_REG_YR);
        buf[PCF8563_REG_ST1] = hi_i2c_read(i2c_devaddress, PCF8563_REG_ST1);

        tm->tm_sec = bcd2bin(buf[PCF8563_REG_SC] & 0x7F);
        tm->tm_min = bcd2bin(buf[PCF8563_REG_MN] & 0x7F);
        tm->tm_hour = bcd2bin(buf[PCF8563_REG_HR] & 0x3F); /* rtc hr 0-23 */
        tm->tm_mday = bcd2bin(buf[PCF8563_REG_DM] & 0x3F);
        tm->tm_wday = buf[PCF8563_REG_DW] & 0x07;
        tm->tm_mon = bcd2bin(buf[PCF8563_REG_MO] & 0x1F) - 1; /* rtc mn 1-12 */
        tm->tm_year = bcd2bin(buf[PCF8563_REG_YR]);

      #if 0
        printk("%s: secs=%d, mins=%d, hours=%d, "
                "mday=%d, mon=%d, year=%d, wday=%d\n",
                __func__,
                tm->tm_sec, tm->tm_min, tm->tm_hour,
                tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
      #endif

        // Century bit. C = 0; indicates the century is 20xx.
     // C = 1; indicates the century is 19xx.
        if(buf[PCF8563_REG_MO] & PCF8563_MO_C)
            tm->tm_year += 1900;
        else
            tm->tm_year += 2000;
        return 0;
}

写RTC pcf8563数据：

static int pcf8563_set_datetime(int i2c_devaddress , rtc_time_t tm)
{
        unsigned char buf[9];
        int Centurybit;
#if 0
        printk("%s: secs=%d, mins=%d, hours=%d, "
                "mday=%d, mon=%d, year=%d, wday=%d\n",
                __func__,
                tm.tm_sec, tm.tm_min, tm.tm_hour,
                tm.tm_mday, tm.tm_mon, tm.tm_year, tm.tm_wday);
#endif

        /* hours, minutes and seconds */
        buf[PCF8563_REG_SC] = bin2bcd(tm.tm_sec);
        buf[PCF8563_REG_MN] = bin2bcd(tm.tm_min);
        buf[PCF8563_REG_HR] = bin2bcd(tm.tm_hour);

        buf[PCF8563_REG_DM] = bin2bcd(tm.tm_mday);

        /* month, 1 - 12 */
        buf[PCF8563_REG_MO] = bin2bcd(tm.tm_mon + 1);

        /* year and century */
        buf[PCF8563_REG_YR] = bin2bcd(tm.tm_year % 100);

        if (tm.tm_year >= 1900 && tm.tm_year < 2000)
            Centurybit = PCF8563_MO_C;
        else if (tm.tm_year >= 2000 && tm.tm_year < 3000)
            Centurybit = 0;
        else
            return -1;

        // Century bit. C = 0; indicates the century is 20xx.
     // C = 1; indicates the century is 19xx.
        buf[PCF8563_REG_MO] |= Centurybit; //add Century bit

        buf[PCF8563_REG_DW] = tm.tm_wday & 0x07;

        /* write register's data */
        hi_i2c_write(i2c_devaddress, PCF8563_REG_SC, buf[PCF8563_REG_SC]);
        hi_i2c_write(i2c_devaddress, PCF8563_REG_MN, buf[PCF8563_REG_MN]);
        hi_i2c_write(i2c_devaddress, PCF8563_REG_HR, buf[PCF8563_REG_HR]);
        hi_i2c_write(i2c_devaddress, PCF8563_REG_DM, buf[PCF8563_REG_DM]);
        hi_i2c_write(i2c_devaddress, PCF8563_REG_MO, buf[PCF8563_REG_MO]);
        hi_i2c_write(i2c_devaddress, PCF8563_REG_YR, buf[PCF8563_REG_YR]);
        hi_i2c_write(i2c_devaddress, PCF8563_REG_DW, buf[PCF8563_REG_DW]);

        return 0;
}

相关控制调用函数：

static int pcf8563_rtc_ioctl(struct inode *inode, struct file *file, unsigned int cmd, unsigned long arg)
{
rtc_time_t tm;
switch (cmd)
{
case RTC_RD_TIME:
pcf8563_get_datetime(i2c_pcf8563, &tm);
return copy_to_user((void *)arg, &tm, sizeof(tm)) ? -EFAULT : 0;

case RTC_SET_TIME:
if (copy_from_user(&tm, (struct rtc_time_t *) arg, sizeof(tm)))
return -EFAULT;
return pcf8563_set_datetime(i2c_pcf8563, tm);
}
return 0;
}

static struct file_operations pcf8563_fops = {
.owner = THIS_MODULE,
.ioctl = pcf8563_rtc_ioctl,
.open = pcf8563_open,
.release = pcf8563_close
};

static struct miscdevice pcf8563_dev = {
MISC_DYNAMIC_MINOR,
"pcf8563",
&pcf8563_fops,
};