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/*

 * Project: S.Ha.R.K.

 *

 * Coordinators:

 *   Giorgio Buttazzo    <giorgio@sssup.it>

 *   Paolo Gai           <pj@gandalf.sssup.it>

 *

 * Authors     :

 *   Paolo Gai           <pj@gandalf.sssup.it>

 *   Massimiliano Giorgi <massy@gandalf.sssup.it>

 *   Luca Abeni          <luca@gandalf.sssup.it>

 *   (see the web pages for full authors list)

 *

 * ReTiS Lab (Scuola Superiore S.Anna - Pisa - Italy)

 *

 * http://www.sssup.it

 * http://retis.sssup.it

 * http://shark.sssup.it

 */

/**

 ------------

 CVS :        $Id: rtc.c,v 1.2 2002-11-11 08:41:31 pj Exp $

 File:        $File$

 Revision:    $Revision: 1.2 $

 Last update: $Date: 2002-11-11 08:41:31 $

 ------------

 Author:      Massimiliano Giorgi

 A source from Linux 2.2.9 modified to work with S.Ha.R.K.

**/

/*

 * Copyright (C) 2000 Paolo Gai

 *

 * This program is free software; you can redistribute it and/or modify

 * it under the terms of the GNU General Public License as published by

 * the Free Software Foundation; either version 2 of the License, or

 * (at your option) any later version.

 *

 * This program is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

 * GNU General Public License for more details.

 *

 * You should have received a copy of the GNU General Public License

 * along with this program; if not, write to the Free Software

 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

 *

 */

/*

 *      Real Time Clock interface for Linux    

 *

 *      Copyright (C) 1996 Paul Gortmaker

 *

 *      This driver allows use of the real time clock (built into

 *      nearly all computers) from user space. It exports the /dev/rtc

 *      interface supporting various ioctl() and also the /proc/rtc

 *      pseudo-file for status information.

 *

 *      The ioctls can be used to set the interrupt behaviour and

 *      generation rate from the RTC via IRQ 8. Then the /dev/rtc

 *      interface can be used to make use of these timer interrupts,

 *      be they interval or alarm based.

 *

 *      The /dev/rtc interface will block on reads until an interrupt

 *      has been received. If a RTC interrupt has already happened,

 *      it will output an unsigned long and then block. The output value

 *      contains the interrupt status in the low byte and the number of

 *      interrupts since the last read in the remaining high bytes. The

 *      /dev/rtc interface can also be used with the select(2) call.

 *

 *      This program is free software; you can redistribute it and/or

 *      modify it under the terms of the GNU General Public License

 *      as published by the Free Software Foundation; either version

 *      2 of the License, or (at your option) any later version.

 *

 *      Based on other minimal char device drivers, like Alan's

 *      watchdog, Ted's random, etc. etc.

 *

 *      1.07    Paul Gortmaker.

 *      1.08    Miquel van Smoorenburg: disallow certain things on the

 *              DEC Alpha as the CMOS clock is also used for other things.

 *      1.09    Nikita Schmidt: epoch support and some Alpha cleanup.

 *

 */

#define RTC_VERSION             "1.09"

#define RTC_IRQ         8       /* Can't see this changing soon.        */

#define RTC_IO_EXTENT   0x10    /* Only really two ports, but...        */

/*

 *      Note that *all* calls to CMOS_READ and CMOS_WRITE are done with

 *      interrupts disabled. Due to the index-port/data-port (0x70/0x71)

 *      design of the RTC, we don't want two different things trying to

 *      get to it at once. (e.g. the periodic 11 min sync from time.c vs.

 *      this driver.)

 */

#include <kernel/kern.h>

#include <drivers/rtc.h>

#include "_rtc.h"

/*

#define CMOS_READ(addr) ({ \

outb_p((addr),RTC_PORT(0)); \

inb_p(RTC_PORT(1)); \

})

#define CMOS_WRITE(val, addr) ({ \

outb_p((addr),RTC_PORT(0)); \

outb_p((val),RTC_PORT(1)); \

})

*/

#define CMOS_READ(addr) (     \

  ll_out(RTC_PORT(0),addr),   \

  ll_in(RTC_PORT(1))          \

)

#define CMOS_WRITE(val, addr) (\

  ll_out(RTC_PORT(0),addr),    \

  ll_out(RTC_PORT(1),val)      \

)

/*

 *      We sponge a minor off of the misc major. No need slurping

 *      up another valuable major dev number for this. If you add

 *      an ioctl, make sure you don't conflict with SPARC's RTC

 *      ioctls.

 */

int get_rtc_time (struct rtc_time *rtc_tm);

int set_rtc_time (struct rtc_time *rtc_tm);

int get_rtc_alm_time (struct rtc_time *alm_tm);

void set_rtc_irq_bit(unsigned char bit);

void mask_rtc_irq_bit(unsigned char bit);

static inline unsigned char rtc_is_updating(void);

/*

 *      Bits in rtc_status. (6 bits of room for future expansion)

 */

#define RTC_IS_OPEN             0x01    /* means /dev/rtc is in use     */

#define RTC_TIMER_ON            0x02    /* missed irq timer active      */

unsigned char rtc_status = 0;           /* bitmapped status byte.       */

unsigned long rtc_freq = 0;             /* Current periodic IRQ rate    */

unsigned long rtc_irq_data = 0;         /* our output to the world      */

/*

 *      If this driver ever becomes modularised, it will be really nice

 *      to make the epoch retain its value across module reload...

 */

static unsigned long epoch = 1900;      /* year corresponding to 0x00   */

unsigned char days_in_mo[] =

{0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};

/*

 * Returns true if a clock update is in progress

 */

static inline unsigned char rtc_is_updating(void)

{

  SYS_FLAGS flags;

  unsigned char uip;

  flags=kern_fsave();

  uip = (CMOS_READ(RTC_FREQ_SELECT) & RTC_UIP);

  kern_frestore(flags);

  return uip;

}

int get_rtc_time(struct rtc_time *rtc_tm)

{

  SYS_FLAGS flags;

  unsigned char ctrl;

  unsigned retries=0;

  struct timespec delay;

  /*

   * read RTC once any update in progress is done. The update

   * can take just over 2ms. We wait 10 to 20ms. There is no need to

   * to poll-wait (up to 1s - eeccch) for the falling edge of RTC_UIP.

   * If you need to know *exactly* when a second has started, enable

   * periodic update complete interrupts, (via ioctl) and then

   * immediately read /dev/rtc which will block until you get the IRQ.

   * Once the read clears, read the RTC time (again via ioctl). Easy.

   */

  /*

  if (rtc_is_updating() != 0)

    while (jiffies - uip_watchdog < 2*HZ/100)

      barrier();

  */

  delay.tv_nsec = 1000000;

  delay.tv_sec = 0;

  while (rtc_is_updating()&&++retries<=5) nanosleep(&delay, NULL);

  if (retries>5) return -1;

  /*

   * Only the values that we read from the RTC are set. We leave

   * tm_wday, tm_yday and tm_isdst untouched. Even though the

   * RTC has RTC_DAY_OF_WEEK, we ignore it, as it is only updated

   * by the RTC when initially set to a non-zero value.

   */

  flags=kern_fsave();

  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);

  ctrl = CMOS_READ(RTC_CONTROL);

  kern_frestore(flags);

  if (!(ctrl & RTC_DM_BINARY) || RTC_ALWAYS_BCD)

    {

      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 += (epoch - 1900)) <= 69)

    rtc_tm->tm_year += 100;

  rtc_tm->tm_mon--;

  return 0;

}

int set_rtc_time(struct rtc_time *rtc_tm)

{

  unsigned char mon, day, hrs, min, sec, leap_yr;

  unsigned char save_control, save_freq_select;

  unsigned int yrs;

  SYS_FLAGS flags;

  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)

    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 -= epoch) > 255)    /* They are unsigned */

    return -EINVAL;

  flags=kern_fsave();

  if (!(CMOS_READ(RTC_CONTROL) & RTC_DM_BINARY)

      || RTC_ALWAYS_BCD) {

    if (yrs > 169) {

      kern_frestore(flags);

      return -EINVAL;

    }

    if (yrs >= 100)

      yrs -= 100;

    BIN_TO_BCD(sec);

    BIN_TO_BCD(min);

    BIN_TO_BCD(hrs);

    BIN_TO_BCD(day);

    BIN_TO_BCD(mon);

    BIN_TO_BCD(yrs);

  }

  save_control = CMOS_READ(RTC_CONTROL);

  CMOS_WRITE((save_control|RTC_SET), RTC_CONTROL);

  save_freq_select = CMOS_READ(RTC_FREQ_SELECT);

  CMOS_WRITE((save_freq_select|RTC_DIV_RESET2), RTC_FREQ_SELECT);

  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);

  CMOS_WRITE(save_control, RTC_CONTROL);

  CMOS_WRITE(save_freq_select, RTC_FREQ_SELECT);

  kern_frestore(flags);

  return 0;

}

int get_rtc_alm_time(struct rtc_time *alm_tm)

{

  SYS_FLAGS flags;

  unsigned char ctrl;

  /*

   * Only the values that we read from the RTC are set. That

   * means only tm_hour, tm_min, and tm_sec.

   */

  flags=kern_fsave();

  alm_tm->tm_sec = CMOS_READ(RTC_SECONDS_ALARM);

  alm_tm->tm_min = CMOS_READ(RTC_MINUTES_ALARM);

  alm_tm->tm_hour = CMOS_READ(RTC_HOURS_ALARM);

  ctrl = CMOS_READ(RTC_CONTROL);

  kern_frestore(flags);

  if (!(ctrl & RTC_DM_BINARY) || RTC_ALWAYS_BCD)

    {

      BCD_TO_BIN(alm_tm->tm_sec);

      BCD_TO_BIN(alm_tm->tm_min);

      BCD_TO_BIN(alm_tm->tm_hour);

    }

  return 0;

}

/*

 * Used to disable/enable interrupts for any one of UIE, AIE, PIE.

 * Rumour has it that if you frob the interrupt enable/disable

 * bits in RTC_CONTROL, you should read RTC_INTR_FLAGS, to

 * ensure you actually start getting interrupts. Probably for

 * compatibility with older/broken chipset RTC implementations.

 * We also clear out any old irq data after an ioctl() that

 * meddles with the interrupt enable/disable bits.

 */

void mask_rtc_irq_bit(unsigned char bit)

{

  unsigned char val;

  SYS_FLAGS flags;

  flags=kern_fsave();

  //cli();

  val = CMOS_READ(RTC_CONTROL);

  val &=  ~bit;

  CMOS_WRITE(val, RTC_CONTROL);

  CMOS_READ(RTC_INTR_FLAGS);

  kern_frestore(flags);

  //rtc_irq_data = 0;

}

void set_rtc_irq_bit(unsigned char bit)

{

  unsigned char val;

  SYS_FLAGS flags;

  flags=kern_fsave();

  //cli();

  val = CMOS_READ(RTC_CONTROL);

  val |= bit;

  CMOS_WRITE(val, RTC_CONTROL);

  CMOS_READ(RTC_INTR_FLAGS);

  //rtc_irq_data = 0;

  kern_frestore(flags);

}

/* added by Massy */

/* to find the date in seconds from the Epoch (1 Gen 1970 00:00 GMT) */

/* (modifing a source from Linux) */

static int day_n[]={

  0,31,59,90,120,151,181,212,243,273,304,334,0,0,0,0

};

time_t sys_getdate(void)

{

  struct rtc_time rtc;

  time_t secs;

  get_rtc_time (&rtc);

  secs = rtc.tm_sec+60l*rtc.tm_min+rtc.tm_hour*3600l+86400l*

    (rtc.tm_mday-1+day_n[rtc.tm_mon]+(rtc.tm_year/4l)

    +rtc.tm_year*365l-

    ((rtc.tm_year & 3) == 0 && rtc.tm_mon < 2 ? 1 : 0)+3653l);

  /* days since 1.1.70 plus 80's leap day */

  /*secs += sys_tz.tz_minuteswest*60;*/

  /*if (sys_tz.tz_dsttime) secs -= 3600;*/

  return secs;

}