linux2.6.27下做DS1302驱动的问题

Question

小弟用的内核版本是2.6.27，处理器AT91RM9200。在内核目录linux-2.6.27/drivers/char，找到ds1302.c文件。大致看了源码，但是不知道如何去修改，请大侠指导。
PA6   <------->   RST
PA22  <------->   CLK
PA23  <------->   I/O

Answer 1

附上ds1302.c的代码。

/*!*************************************************************************** *! *! FILE NAME  : ds1302.c *! *! DESCRIPTION: Implements an interface for the DS1302 RTC *! *! Functions exported: ds1302_readreg, ds1302_writereg, ds1302_init, get_rtc_status *! *! --------------------------------------------------------------------------- *! *! (C) Copyright 1999, 2000, 2001  Axis Communications AB, LUND, SWEDEN *! *!***************************************************************************/ #include <linux/fs.h> #include <linux/init.h> #include <linux/mm.h> #include <linux/module.h> #include <linux/miscdevice.h> #include <linux/delay.h> #include <linux/bcd.h> #include <linux/smp_lock.h> #include <linux/uaccess.h> #include <linux/io.h> #include <asm/system.h> #include <asm/rtc.h> #if defined(CONFIG_M32R) #include <asm/m32r.h> #endif #define RTC_MAJOR_NR 121 /* local major, change later */ static const char ds1302_name[] = "ds1302"; /* Send 8 bits. */ static void out_byte_rtc(unsigned int reg_addr, unsigned char x) {     //RST H     outw(0x0001,(unsigned long)PLD_RTCRSTODT);     //write data     outw(((x<<8)|(reg_addr&0xff)),(unsigned long)PLD_RTCWRDATA);     //WE     outw(0x0002,(unsigned long)PLD_RTCCR);     //wait     while(inw((unsigned long)PLD_RTCCR));     //RST L     outw(0x0000,(unsigned long)PLD_RTCRSTODT); } static unsigned char in_byte_rtc(unsigned int reg_addr) {     unsigned char retval;     //RST H     outw(0x0001,(unsigned long)PLD_RTCRSTODT);     //write data     outw((reg_addr&0xff),(unsigned long)PLD_RTCRDDATA);     //RE     outw(0x0001,(unsigned long)PLD_RTCCR);     //wait     while(inw((unsigned long)PLD_RTCCR));     //read data     retval=(inw((unsigned long)PLD_RTCRDDATA) & 0xff00)>>8;     //RST L     outw(0x0000,(unsigned long)PLD_RTCRSTODT);     return retval; } /* Enable writing. */ static void ds1302_wenable(void) {     out_byte_rtc(0x8e,0x00); } /* Disable writing. */ static void ds1302_wdisable(void) {     out_byte_rtc(0x8e,0x80); } /* Read a byte from the selected register in the DS1302. */ unsigned char ds1302_readreg(int reg) {     unsigned char x;     x=in_byte_rtc((0x81 | (reg << 1))); /* read register */     return x; } /* Write a byte to the selected register. */ void ds1302_writereg(int reg, unsigned char val) {     ds1302_wenable();     out_byte_rtc((0x80 | (reg << 1)),val);     ds1302_wdisable(); } void get_rtc_time(struct rtc_time *rtc_tm) {     unsigned long flags;     local_irq_save(flags);     rtc_tm->tm_sec = CMOS_READ(RTC_SECONDS);     rtc_tm->tm_min = CMOS_READ(RTC_MINUTES);     rtc_tm->tm_hour = CMOS_READ(RTC_HOURS);     rtc_tm->tm_mday = CMOS_READ(RTC_DAY_OF_MONTH);     rtc_tm->tm_mon = CMOS_READ(RTC_MONTH);     rtc_tm->tm_year = CMOS_READ(RTC_YEAR);     local_irq_restore(flags);     BCD_TO_BIN(rtc_tm->tm_sec);     BCD_TO_BIN(rtc_tm->tm_min);     BCD_TO_BIN(rtc_tm->tm_hour);     BCD_TO_BIN(rtc_tm->tm_mday);     BCD_TO_BIN(rtc_tm->tm_mon);     BCD_TO_BIN(rtc_tm->tm_year);     /*      * Account for differences between how the RTC uses the values      * and how they are defined in a struct rtc_time;      */     if (rtc_tm->tm_year <= 69)         rtc_tm->tm_year += 100;     rtc_tm->tm_mon--; } static unsigned char days_in_mo[] =     {0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31}; /* ioctl that supports RTC_RD_TIME and RTC_SET_TIME (read and set time/date). */ static long rtc_ioctl(struct file *file, unsigned int cmd, unsigned long arg) {     unsigned long flags;     switch(cmd) {         case RTC_RD_TIME:    /* read the time/date from RTC    */         {             struct rtc_time rtc_tm;             memset(&rtc_tm, 0, sizeof (struct rtc_time));             lock_kernel();             get_rtc_time(&rtc_tm);             unlock_kernel();             if (copy_to_user((struct rtc_time*)arg, &rtc_tm, sizeof(struct rtc_time)))                 return -EFAULT;             return 0;         }         case RTC_SET_TIME:    /* set the RTC */         {             struct rtc_time rtc_tm;             unsigned char mon, day, hrs, min, sec, leap_yr;             unsigned int yrs;             if (!capable(CAP_SYS_TIME))                 return -EPERM;             if (copy_from_user(&rtc_tm, (struct rtc_time*)arg, sizeof(struct rtc_time)))                 return -EFAULT;             yrs = rtc_tm.tm_year + 1900;             mon = rtc_tm.tm_mon + 1;   /* tm_mon starts at zero */             day = rtc_tm.tm_mday;             hrs = rtc_tm.tm_hour;             min = rtc_tm.tm_min;             sec = rtc_tm.tm_sec;             if ((yrs < 1970) || (yrs > 2069))                 return -EINVAL;             leap_yr = ((!(yrs % 4) && (yrs % 100)) || !(yrs % 400));             if ((mon > 12) || (day == 0))                 return -EINVAL;             if (day > (days_in_mo[mon] + ((mon == 2) && leap_yr)))                 return -EINVAL;             if ((hrs >= 24) || (min >= 60) || (sec >= 60))                 return -EINVAL;             if (yrs >= 2000)                 yrs -= 2000;    /* RTC (0, 1, ... 69) */             else                 yrs -= 1900;    /* RTC (70, 71, ... 99) */             BIN_TO_BCD(sec);             BIN_TO_BCD(min);             BIN_TO_BCD(hrs);             BIN_TO_BCD(day);             BIN_TO_BCD(mon);             BIN_TO_BCD(yrs);             lock_kernel();             local_irq_save(flags);             CMOS_WRITE(yrs, RTC_YEAR);             CMOS_WRITE(mon, RTC_MONTH);             CMOS_WRITE(day, RTC_DAY_OF_MONTH);             CMOS_WRITE(hrs, RTC_HOURS);             CMOS_WRITE(min, RTC_MINUTES);             CMOS_WRITE(sec, RTC_SECONDS);             local_irq_restore(flags);             unlock_kernel();             /* Notice that at this point, the RTC is updated but              * the kernel is still running with the old time.              * You need to set that separately with settimeofday              * or adjtimex.              */             return 0;         }         case RTC_SET_CHARGE: /* set the RTC TRICKLE CHARGE register */         {             int tcs_val;             if (!capable(CAP_SYS_TIME))                 return -EPERM;             if(copy_from_user(&tcs_val, (int*)arg, sizeof(int)))                 return -EFAULT;             lock_kernel();             tcs_val = RTC_TCR_PATTERN | (tcs_val & 0x0F);             ds1302_writereg(RTC_TRICKLECHARGER, tcs_val);             unlock_kernel();             return 0;         }         default:             return -EINVAL;     } } int get_rtc_status(char *buf) {     char *p;     struct rtc_time tm;     p = buf;     get_rtc_time(&tm);     /*      * There is no way to tell if the luser has the RTC set for local      * time or for Universal Standard Time (GMT). Probably local though.      */     p += sprintf(p,         "rtc_time\t: %02d:%02d:%02d\n"         "rtc_date\t: %04d-%02d-%02d\n",         tm.tm_hour, tm.tm_min, tm.tm_sec,         tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday);     return  p - buf; } /* The various file operations we support. */ static const struct file_operations rtc_fops = {     .owner        = THIS_MODULE,     .unlocked_ioctl    = rtc_ioctl, }; /* Probe for the chip by writing something to its RAM and try reading it back. */ #define MAGIC_PATTERN 0x42 static int __init ds1302_probe(void) {     int retval, res, baur;     baur=(boot_cpu_data.bus_clock/(2*1000*1000));     printk("%s: Set PLD_RTCBAUR = %d\n", ds1302_name,baur);     outw(0x0000,(unsigned long)PLD_RTCCR);     outw(0x0000,(unsigned long)PLD_RTCRSTODT);     outw(baur,(unsigned long)PLD_RTCBAUR);     /* Try to talk to timekeeper. */     ds1302_wenable();     /* write RAM byte 0 */     /* write something magic */     out_byte_rtc(0xc0,MAGIC_PATTERN);     /* read RAM byte 0 */     if((res = in_byte_rtc(0xc1)) == MAGIC_PATTERN) {         char buf[100];         ds1302_wdisable();         printk("%s: RTC found.\n", ds1302_name);         get_rtc_status(buf);         printk(buf);         retval = 1;     } else {         printk("%s: RTC not found.\n", ds1302_name);         retval = 0;     }     return retval; } /* Just probe for the RTC and register the device to handle the ioctl needed. */ int __init ds1302_init(void) {     if (!ds1302_probe()) {         return -1;       }     return 0; } static int __init ds1302_register(void) {     ds1302_init();     if (register_chrdev(RTC_MAJOR_NR, ds1302_name, &rtc_fops)) {         printk(KERN_INFO "%s: unable to get major %d for rtc\n",                ds1302_name, RTC_MAJOR_NR);         return -1;     }     return 0; } module_init(ds1302_register);

Answer 2

你先把你要做什么，以及这段代码是如何工作的搞清楚再说吧

Answer 3

谢谢楼主

Answer 4

原帖由 zhj1011 于 2009-4-7 17:00 发表
谢谢楼主

You are楼主

Answer 5

原帖由 dreamice 于 2009/4/7 19:27 发表

You are楼主

BZ先生, 不要这么惊讶

Answer 6

LZ, 内核里有了驱动, 你还要做什么呢? 你没有详述你的需要和问题.

Answer 7

是这样的 2.6内核下面 有两个ds1302的驱动 一个位于drivers/char/ds1302.c 一个是drivers/rtc/rtc-ds1302.c
看了char下的Kconfig和rtc/Kconfig
drivers/char/ds1302.c 依赖于 M32R && (PLAT_M32700UT || PLAT_OPSPUT)
drivers/rtc/rtc-ds1302.c依赖于 depends on SH_SECUREEDGE5410
这两个驱动都不是针对ARM体系结构的。
我现在是要做一个AT91RM9200上的DS1302驱动 通过三个GPIO管脚实现通信
我现在修改char/ds1302.c代码 编译通过后 加载到内核后 出错
移植这个非ARM体系结构的去到ARM体系结构下 需要修改哪些东西呢？ 只是一些管脚的具体定义就OK了吗？ 谢谢

Answer 8

好像不止三个口啊，并口？ arch/cris/arch-v10/drivers 下面有个 ds1302 的好像才是模拟的

[ 本帖最后由 star316 于 2009-4-8 11:37 编辑 ]

Answer 9

手头没有2.6.27.   看了一下2.6.28的ds1302.c,  我认为你要先确认RTC的地址正确, 几个函数都是针对地址/寄存器的操作.