+++ /dev/null
-// SPDX-License-Identifier: GPL-2.0
-/*!***************************************************************************
-*!
-*! 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/delay.h>
-#include <linux/bcd.h>
-#include <linux/mutex.h>
-#include <linux/uaccess.h>
-#include <linux/io.h>
-
-#include <asm/rtc.h>
-#if defined(CONFIG_M32R)
-#include <asm/m32r.h>
-#endif
-
-#define RTC_MAJOR_NR 121 /* local major, change later */
-
-static DEFINE_MUTEX(rtc_mutex);
-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);
-
- rtc_tm->tm_sec = bcd2bin(rtc_tm->tm_sec);
- rtc_tm->tm_min = bcd2bin(rtc_tm->tm_min);
- rtc_tm->tm_hour = bcd2bin(rtc_tm->tm_hour);
- rtc_tm->tm_mday = bcd2bin(rtc_tm->tm_mday);
- rtc_tm->tm_mon = bcd2bin(rtc_tm->tm_mon);
- rtc_tm->tm_year = bcd2bin(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));
- mutex_lock(&rtc_mutex);
- get_rtc_time(&rtc_tm);
- mutex_unlock(&rtc_mutex);
- 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) */
-
- sec = bin2bcd(sec);
- min = bin2bcd(min);
- hrs = bin2bcd(hrs);
- day = bin2bcd(day);
- mon = bin2bcd(mon);
- yrs = bin2bcd(yrs);
-
- mutex_lock(&rtc_mutex);
- 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);
- mutex_unlock(&rtc_mutex);
-
- /* 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;
-
- mutex_lock(&rtc_mutex);
- tcs_val = RTC_TCR_PATTERN | (tcs_val & 0x0F);
- ds1302_writereg(RTC_TRICKLECHARGER, tcs_val);
- mutex_unlock(&rtc_mutex);
- 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,
- .llseek = noop_llseek,
-};
-
-/* 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);
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