linux下的i2c與時鐘芯片pcf8563通信(三)

2012/7/19

linux下的i2c與時鐘芯片pcf8563通信

by: 韓大衛 @吉林師範大學

1，本程序增加了對星期寄存器（wday）的寫操作。
2, 本程序將i2c-test 改爲rtdate 命令,並將rtdate作爲最終命令發佈。
3，在linux下，成功地在用戶層操作了時鐘芯片pcf8563的寄存器。
4，本程序考慮到了不同的系統中的rtc時鐘芯片掛在不同的i2c bus的位置。、
      比如：如果掛在 /dev/i2c-0 下，那麼就只能打開/dev/i2c-0 進行操作，否則的話read/write 均會失敗，那麼這樣就需要我們手動的傳入參數，這需在程序中加入相應的判斷條件。同時爲了最大程度上做到便捷，如果不使用路徑參數的話，那麼程序中給出了默認路徑/dev/i2c-1, 我們這樣就可以直接

#rtdate -s 2012.7.19-19.36.00 修改硬件時間。
#rtdate -s 19.36.00 修改硬件時間
#rtdate -r 顯示硬件時間
#rtdate -l 顯示系統時間

需要手動加路徑的話：
#rtdate -d /dev/i2c-10 -s 18:20:30
這樣可以做到在不同的嵌入式系統中，不修改代碼的情況下操作時鐘芯片讀寫硬件時間，強化了軟件的健壯性。

我們嵌入式系統中的cpu是Cavium Networks OCTEON CN5220，基於64bit的mips處理器。

********************************************* *******************************
                                             轉載請務必表明出處。韓大衛@吉林師範大學。

********************************************** *******************************
main.c
**************** ******************************************
#include "i2c.h"

#define TIMEOUT   3
#define RETRY   3

static int fd;

static inline int is_leap_year(unsigned int year){

        return (!(year % 4) && (year % 100)) || !(year % 400);
}

int rtc_month_days(unsigned int month, unsigned int year){

        return rtc_days_in_month[month - 1] + (is_leap_year(year) && month == 1);
}

/*
*   test year.mon.mday.wday.hour.min.sec
*/
int rtc_valid_tm(struct rtc_time *tm)
{
        if(   tm->tm_year < 1970
       || tm->tm_year >2069
                || ((unsigned)tm->tm_mon) > 12
                || tm->tm_mday < 0
                || tm->tm_mday > rtc_month_days(tm->tm_mon, tm->tm_year)
                || ((unsigned)tm->tm_hour) >= 24
                || ((unsigned)tm->tm_min) >= 60
                || ((unsigned)tm->tm_sec) >= 60)
                return -EINVAL;

        return 0;
}

/*
*   test hour:min:sec
*/
int rtc_valid_half_tm(struct rtc_time *tm)
{
       if((unsigned)tm->tm_hour >= 24 ||
             (unsigned)tm->tm_min >= 60 ||
             (unsigned)tm->tm_sec >= 60)
                return -EINVAL;

        return 0;
}

int i_open(unsigned char* dev, unsigned int timeout, unsigned int retry){

        return i2c_open(dev,timeout,retry);
}

int read_data(u16 addr, u8 offset, u8 *val){
   int ret;

   ret = i2c_read_data(addr,offset,val);
   if(ret < 0){
       printf("%s error!\n",__FUNCTION__);
       exit(-1);
   }
   return 0;
}

int write_data(u16 addr, u8 offset, u8 val){
   int ret;

   ret = i2c_write_data(addr,offset,val);
   if(ret < 0){
       printf("%s error!\n",__FUNCTION__);
       exit(-1);
   }
   return 0;
}

int get_week_data(int y,int m,int d){
   unsigned int w, c;

   if (m <= 2){
       m |= 4;
       y--;
   }
   c =   y/100;
   c &=   0x03;
   y %=   100;
   w =   ((c | (c << 2)) + (y + (y >> 2)) + (13 * m + 8)/ 5 + d) % 7;

   return w;
}

/*
*   -s YYYY.MM.DD-hh.mm.ss
*/
int time_year_begin(char* ptr,struct rtc_time* tm){

   if( !(*(ptr+4) == '.' || *(ptr+4) == ':' )){
       printf("TIME Format error !\n");
       exit(-1);
   }

   u8 offset;
   u16 addr        =    0x51;
   int i           =    0;
   int set_hour_flags   =   0;
   unsigned char buf[8]   =   {0};
   int data[10]       =   {0};

   /* get year */
        data[i++] = atoi(ptr);

        while( *ptr ){
                if( *ptr == '.' || *ptr == ':'){
                        ptr++;
           /* get mon and mday */
                        data[i++] = atoi(ptr);
       }
                ptr++;
                if( *ptr == '-'){
           set_hour_flags = 1;
                        ptr++;
           /* get hour */
                        data[i++] = atoi(ptr);
                        while( *ptr ){
                                if( *ptr == '.' || *ptr == ':' ){
                                        ptr++;
                   /* get min and sec */
                                        data[i++] = atoi(ptr);
                                }
                                else ptr++;
                        }
                        break;
                }
        }
        tm->tm_year     =       data[0];
        tm->tm_mon      =       data[1];
        tm->tm_mday     =       data[2];
        tm->tm_hour     =       data[3];
        tm->tm_min      =       data[4];
        tm->tm_sec      =       data[5];
   tm->tm_wday   =   get_week_data(tm->tm_year,tm->tm_mon,tm->tm_mday);

   if(rtc_valid_tm(tm) < 0){
       printf("date/time is not valid.set time error!\n");
       exit(-1);
   }

   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);
        buf[PCF8563_REG_DW]   =   tm->tm_wday & 0x07;
   buf[PCF8563_REG_MO]   =   bin2bcd(tm->tm_mon);
        buf[PCF8563_REG_YR]   =   bin2bcd(tm->tm_year % 100);

   if ( tm->tm_year/2000 )
       buf[PCF8563_REG_MO] |= 0x00;
   else
       buf[PCF8563_REG_MO] |= PCF8563_MO_C;

   /* write year-wday or year-sec   */
   for(offset = set_hour_flags? PCF8563_REG_SC : PCF8563_REG_DM; offset <= PCF8563_REG_YR ; offset++ ){
       write_data(addr,offset,buf[offset]);
   }
   rtc_time_list();
        return 0;
}

/*
*   -s hh.mm.ss
*/
int time_hour_begin(char *ptr,struct rtc_time* tm){

   if( !(*(ptr+2) == '.' || *(ptr+1) == '.' || *(ptr+2) == ':' || *(ptr+1) == ':') ){
                printf("TIME Format error !\n");
                exit(-1);
        }

   u8 offset;
   u16 addr        =   0x51;
        int i            =   0;
   unsigned char buf[4]   =   {0};
   int data[10]       =   {0};

   /* get hour */
        data[i++] = atoi(ptr);
        while( *ptr ){
                if( *ptr == '.' || *ptr == ':'){
                        ptr++;
           /* get min and sec */
                        data[i++] = atoi(ptr);
                }
                else
                        ptr++;
        }

        tm->tm_hour     =       data[0];
        tm->tm_min      =       data[1];
        tm->tm_sec      =       data[2];

   if(rtc_valid_half_tm(tm) < 0){
       printf("date/time is not valid.set time error!\n");
       exit(-1);
   }

   buf[PCF8563_REG_SC]   =   bin2bcd(tm->tm_sec);
        buf[PCF8563_REG_MN]   =   bin2bcd(tm->tm_min);
        buf[PCF8563_REG_HR]    =   bin2bcd(tm->tm_hour);

   for(offset = PCF8563_REG_SC; offset <= PCF8563_REG_HR ; offset++ ){
       write_data(addr,offset,buf[offset]);
   }

   rtc_time_list();
        return 0;
}

int rtc_time_list(void){

   u16 addr   =   0x51;
   u8 offset   =   0x00;
   u8 buf[13]   =   {0};
   int data[10]   =   {0};
   struct rtc_time *tm = (struct rtc_time*)malloc(sizeof(struct rtc_time));

   read_data(addr, offset, buf);

   tm->tm_sec   =   buf[PCF8563_REG_SC] & 0x7F;
        tm->tm_min   =   buf[PCF8563_REG_MN] & 0x7F;
        tm->tm_hour   =   buf[PCF8563_REG_HR] & 0x3F;   // rtc hr 0-23
        tm->tm_mday   =   buf[PCF8563_REG_DM] & 0x3F;
        tm->tm_wday   =   buf[PCF8563_REG_DW] & 0x07;
        tm->tm_mon   =   buf[PCF8563_REG_MO] & 0x1F;   // rtc mn 1-12 -1 :tm_mon: [0-11]
        tm->tm_year   =   buf[PCF8563_REG_YR];

   if(buf[PCF8563_REG_MO] & PCF8563_MO_C)
       tm->tm_year   +=   0x1900;           //MO:8bit = 1   :1900
   else
       tm->tm_year   +=   0x2000;           //MO:8bit = 0   :2000

   printf("%4x:%02x:%02x ",
                 tm->tm_year, tm->tm_mon, tm->tm_mday);

   switch(tm->tm_wday){
       case 1 :
           printf("Mon ");break;
       case 2 :
           printf("Tus ");break;
       case 3 :
           printf("Wed ");break;
       case 4 :
           printf("Thu ");break;
       case 5 :
           printf("Fir ");break;
       case 6 :
           printf("Sat ");break;
       case 7 :
           printf("Sun ");break;
   }
   printf("%02x:%02x:%02x\n",
                 tm->tm_hour, tm->tm_min, tm->tm_sec);
   return 0;
}

int sys_time_list(){

   struct tm* ptr;
   time_t lt;

   lt = time(NULL);
   ptr = localtime(&lt);

   printf("%4d:",ptr->tm_year + 1900);
   printf("%02d:",ptr->tm_mon + 1);
   printf("%02d ",ptr->tm_mday);

   switch(ptr->tm_wday){
       case 1 :
           printf("Mon ");break;
       case 2 :
           printf("Tus ");break;
       case 3 :
           printf("Wed ");break;
       case 4 :
           printf("Thu ");break;
       case 5 :
           printf("Fir ");break;
       case 6 :
           printf("Sat ");break;
       case 7 :
           printf("Sun ");break;
   }
   printf("%02d:",ptr->tm_hour);
   printf("%02d:",ptr->tm_min);
   printf("%02d\n",ptr->tm_sec);

   return 0;
}

int i2c_rtc_data(char* ptr){

   struct rtc_time* tm   =   (struct rtc_time*)malloc(sizeof(struct rtc_time));
   int c            =   atoi(ptr);

        if( c /1000 )
                time_year_begin(ptr,tm);
        else
                time_hour_begin(ptr,tm);

   return 0;
}

int help_info(void){
   printf("\nUsage: rtdate [-d PATH] [OPTIONS]\n");
   printf("\nOr:    rtdate [-d PATH] -s TIME \n");
        printf("\nDisplay rtc-time or sys-time, or set time.\n");
        printf("\nOptions:\n");
        printf("\n\t-r\t\tshow rtc-time\n");
        printf("\n\t-l\t\tshow sys-time\n");
        printf("\n\t-s TIME\ttset rtc-time\n");
        printf("\n\t-h or --help\tshow help information\n");
        printf("\nRecognized formats for TIME:\n");
        printf("\n\tYYYY.MM.DD-hh.mm[.ss]\n");
        printf("\n\tYYYY.MM.DD\n");
        printf("\n\thh.mm[.ss]\n");
        printf("\n\thh:mm[:ss]\n");
        printf("\n\t'.' can be replaced by ':'\n");
   printf("\nFor example\n\trtdate -s YYYY.MM.DD \n");
   printf("\n\trtdate -s hh.mm:ss \n");
   printf("\n\trtdate -d /dev/i2c-1 -s YYYY:MM:DD-hh.mm:ss \n\n");

   return 0;
}

void path(char* argv){

   fd = i_open(argv,TIMEOUT,RETRY);
   if( fd < 0 ){
       printf("i2c_open error!\n");
       exit(-1);
   }

}

int main(int argc,char* argv[]){

   int sw = argc;

   if( argc >= 3){
       if(!strcmp(argv[1],   "-d")){
           path(argv[2]);
           sw -= 2;
       }else{
           path("/dev/i2c-1");
       }
   }else{
       path("/dev/i2c-1");
   }

   switch(sw){
   case 1: {
       if( rtc_time_list() ){
           printf("rtctime_show error!\n");
           exit(-1);
       }
       break;
   }
   case 2: {
       if(!strcmp(argv[argc-1],"-l")){
           if( sys_time_list() ){
               printf("systime_show error!\n");
               exit(-1);
           }
       }else if(!strcmp(argv[argc-1],"-r")){
           if( rtc_time_list() ){
               printf("rtctime_show error!\n");
               exit(-1);
           }
       }else if(!strcmp(argv[argc-1],"-h") || !strcmp(argv[argc-1],"--help" ) ) {
               help_info();
       }else{
           printf("useless operation %s ...\n Please try -h or --help for more information\n",argv[argc-1]);
           exit(-1);
       }
       break;
   }
   case 3: {
       if(!strcmp(argv[argc-2], "-s")){
           i2c_rtc_data(argv[argc-1]);
       }
       break;
   }
   default:
       printf("command error!\nPlease input -h or--help for more information"),exit(-1);
   }

   close(fd);

   return 0;
}

************************** *********************************************

i2c.c :

******************* *****************************************
#include "i2c.h"

static int fd;

int
i2c_read_data(u16 addr, u8 offset, u8 *val)
{
   int i,ret = 0;

   struct i2c_rdwr_ioctl_data *data;

   if ((data = (struct i2c_rdwr_ioctl_data *)malloc(sizeof(struct i2c_rdwr_ioctl_data))) == NULL)
   return -1;

   data->nmsgs = 2;
   if ((data->msgs = (struct i2c_msg *)malloc(data->nmsgs * sizeof(struct i2c_msg))) == NULL) {
       ret = -1;
       goto errexit3;
   }
   if ((data->msgs[0].buf = (unsigned char *)malloc(sizeof(unsigned char))) == NULL) {
       ret = -1;
       goto errexit2;
   }
   if ((data->msgs[1].buf = (unsigned char *)malloc(sizeof(unsigned char))) == NULL) {
       ret = -1;
       goto errexit1;
   }

   data->msgs[0].addr = addr;
   data->msgs[0].flags = 0;
   data->msgs[0].len = 1;
   data->msgs[0].buf[0] = offset;

   data->msgs[1].addr = addr;
   data->msgs[1].flags = I2C_M_RD;
   data->msgs[1].len = 13;           //original data is 1
   data->msgs[1].buf[0] = 0;

   if ((ret = __i2c_send(fd, data)) < 0)
       goto errexit0;

   for(i = 0 ;i < data->msgs[1].len; i++)
       val[i] = data->msgs[1].buf[i];

errexit0:
   free(data->msgs[1].buf);
errexit1:
   free(data->msgs[0].buf);
errexit2:
   free(data->msgs);
errexit3:
   free(data);

   return ret;
}

int
i2c_write_data(u16 addr, u8 offset, u8 val)
{
   int ret = 0;

   struct i2c_rdwr_ioctl_data *data;

   if ((data = (struct i2c_rdwr_ioctl_data *)malloc(sizeof(struct i2c_rdwr_ioctl_data))) == NULL)
       return -1;

   data->nmsgs = 1;
   if ((data->msgs = (struct i2c_msg *)malloc(data->nmsgs * sizeof(struct i2c_msg))) == NULL) {
       ret = -1;
       goto errexit2;
   }
   if ((data->msgs[0].buf = (unsigned char *)malloc(2 * sizeof(unsigned char))) == NULL) {
       ret = -1;
       goto errexit1;
   }

   data->msgs[0].addr = addr;
   data->msgs[0].flags = 0;
   data->msgs[0].len = 2;
   data->msgs[0].buf[0] = offset;
   data->msgs[0].buf[1] = val;

   if ((ret = __i2c_send(fd, data)) < 0)
       goto errexit0;

errexit0:
   free(data->msgs[0].buf);
errexit1:
   free(data->msgs);
errexit2:
   free(data);

   return ret;
}

int
i2c_open(unsigned char* dev, unsigned int timeout, unsigned int retry)
{
   if ((fd = open(dev, O_RDWR)) < 0)
       return fd;

   __i2c_set(fd, timeout, retry);

   return fd;
}

static int
__i2c_send(int fd, struct i2c_rdwr_ioctl_data *data)
{
   if (fd < 0)
       return -1;

   if (data == NULL)
       return -1;

   if (data->msgs == NULL || data->nmsgs == 0)
       return -1;

   return ioctl(fd, I2C_RDWR, (unsigned long)data) ;
}

static int
__i2c_set(int fd, unsigned int timeout, unsigned int retry)
{
   if (fd == 0 )
       return -1;

   ioctl(fd, I2C_TIMEOUT, timeout ? timeout : I2C_DEFAULT_TIMEOUT);

   ioctl(fd, I2C_RETRIES, retry ? retry : I2C_DEFAULT_RETRY);

   return 0;
}

void
i2c_close(int fd)
{
   if (fd < 0)
       return;

   close(fd);
}

unsigned bcd2bin(unsigned char val)
{
        return (val & 0x0f) + (val >> 4) * 10;
}

unsigned char bin2bcd(unsigned val)
{
        return ((val / 10) << 4) + val % 10;
}

********* *******************************************************

i2c.h :

******************* *******************************************

#ifndef I2C_H
#define I2C_H

#include <linux/types.h>
#include <linux/i2c.h>
#include <linux/i2c-dev.h>
#include <linux/rtc.h>
#include <stdio.h>
#include <time.h>
#include <stdlib.h>
#include <fcntl.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/ioctl.h>
#include <errno.h>
#include <string.h>

#define I2C_DEFAULT_TIMEOUT       1
#define I2C_DEFAULT_RETRY       3

#define PCF8563_REG_SC          0x02
#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_MO_C            0x80

typedef unsigned char           u8;
typedef unsigned short          u16;
typedef unsigned int            u32;
typedef unsigned long long      u64;
typedef signed char             s8;
typedef short                   s16;
typedef int                     s32;
typedef long long               s64;

static const unsigned char rtc_days_in_month[] = {
        31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31
};

unsigned bcd2bin(unsigned char val);

unsigned bcd2bin(unsigned char val);

static int
__i2c_send(int fd, struct i2c_rdwr_ioctl_data *data);

static int
__i2c_set(int fd, unsigned int timeout, unsigned int retry);

int
i2c_read_data(u16 addr, u8 offset, u8 *val);

int
i2c_write_data(u16 addr, u8 offset, u8 val);

int
i2c_open(unsigned char* dev, unsigned int timeout, unsigned int retry);

#endif

*************** *********************************************************

韓大衛

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