FreeBSD/Linux Kernel Cross Reference
sys/powerpc/mpc85xx/ds1553_core.c

     /*-
      * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
      *
      * Copyright (C) 2006-2008 Semihalf, Grzegorz Bernacki
      * All rights reserved.
      *
      * Redistribution and use in source and binary forms, with or without
      * modification, are permitted provided that the following conditions
      * are met:
     * 1. Redistributions of source code must retain the above copyright
     *    notice, this list of conditions and the following disclaimer.
     * 2. Redistributions in binary form must reproduce the above copyright
     *    notice, this list of conditions and the following disclaimer in the
     *    documentation and/or other materials provided with the distribution.
     *
     * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
     * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     * ARE DISCLAIMED.  IN NO EVENT SHALL AUTHOR OR CONTRIBUTORS BE LIABLE
     * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     * SUCH DAMAGE.
     *
     */
    
    #include <sys/cdefs.h>
    __FBSDID("$FreeBSD$");
    
    #include <sys/param.h>
    #include <sys/systm.h>
    #include <sys/bus.h>
    #include <sys/clock.h>
    #include <sys/lock.h>
    #include <sys/mutex.h>
    
    #include <machine/bus.h>
    
    #include <powerpc/mpc85xx/ds1553_reg.h>
    
    static uint8_t ds1553_direct_read(device_t, bus_size_t);
    static void ds1553_direct_write(device_t, bus_size_t, uint8_t);
    
    int
    ds1553_attach(device_t dev)
    {
            struct ds1553_softc *sc;
            uint8_t sec, flags;
    
            sc = device_get_softc(dev);
    
            if (mtx_initialized(&sc->sc_mtx) == 0) {
                    device_printf(dev, "%s: mutex not initialized\n", __func__);
                    return (ENXIO);
            }
    
            if (sc->sc_read == NULL)
                    sc->sc_read = ds1553_direct_read;
            if (sc->sc_write == NULL)
                    sc->sc_write = ds1553_direct_write;
    
            sc->year_offset = POSIX_BASE_YEAR;
    
            mtx_lock_spin(&sc->sc_mtx);
    
            /* Turn RTC on if it was not on */
            sec = (*sc->sc_read)(dev, DS1553_OFF_SECONDS);
            if (sec & DS1553_BIT_OSC) {
                    sec &= ~(DS1553_BIT_OSC);
                    (*sc->sc_write)(dev, DS1553_OFF_SECONDS, sec);
            }
    
            /* Low-battery check */
            flags = (*sc->sc_read)(dev, DS1553_OFF_FLAGS);
            if (flags & DS1553_BIT_BLF)
                    device_printf(dev, "voltage-low detected.\n");
    
            mtx_unlock_spin(&sc->sc_mtx);
    
            return (0);
    }
    
    /*
     * Get time of day and convert it to a struct timespec.
     * Return 0 on success, an error number otherwise.
     */
    int
    ds1553_gettime(device_t dev, struct timespec *ts)
    {
            struct clocktime ct;
            struct ds1553_softc *sc;
            uint8_t control;
    
            sc = device_get_softc(dev);
    
            mtx_lock_spin(&sc->sc_mtx);
   
           control = (*sc->sc_read)(dev, DS1553_OFF_CONTROL) | DS1553_BIT_READ;
           (*sc->sc_write)(dev, DS1553_OFF_CONTROL, control);
   
           ct.nsec = 0;
           ct.sec = FROMBCD((*sc->sc_read)(dev, DS1553_OFF_SECONDS) &
               DS1553_MASK_SECONDS);
           ct.min = FROMBCD((*sc->sc_read)(dev, DS1553_OFF_MINUTES) &
               DS1553_MASK_MINUTES);
           ct.hour = FROMBCD((*sc->sc_read)(dev, DS1553_OFF_HOURS) &
               DS1553_MASK_HOUR);
           ct.dow = FROMBCD((*sc->sc_read)(dev, DS1553_OFF_DAYOFWEEK) &
               DS1553_MASK_DAYOFWEEK) - 1;
           ct.day = FROMBCD((*sc->sc_read)(dev, DS1553_OFF_DATE) &
               DS1553_MASK_DATE);
           ct.mon = FROMBCD((*sc->sc_read)(dev, DS1553_OFF_MONTH) &
               DS1553_MASK_MONTH);
           ct.year = FROMBCD((*sc->sc_read)(dev, DS1553_OFF_YEAR));
   
           control &= ~DS1553_BIT_READ;
           (*sc->sc_write)(dev, DS1553_OFF_CONTROL, control);
   
           ct.year += sc->year_offset;
   
           mtx_unlock_spin(&sc->sc_mtx);
   
           return (clock_ct_to_ts(&ct, ts));
   }
   
   /*
    * Set the time of day clock based on the value of the struct timespec arg.
    * Return 0 on success, an error number otherwise.
    */
   int
   ds1553_settime(device_t dev, struct timespec *ts)
   {
           struct clocktime ct;
           struct ds1553_softc *sc;
           uint8_t control;
   
           sc = device_get_softc(dev);
           bzero(&ct, sizeof(struct clocktime));
   
           /* Accuracy is only one second. */
           if (ts->tv_nsec >= 500000000)
                   ts->tv_sec++;
           ts->tv_nsec = 0;
           clock_ts_to_ct(ts, &ct);
   
           ct.year -= sc->year_offset;
   
           mtx_lock_spin(&sc->sc_mtx);
   
           /* Halt updates to external registers */
           control = (*sc->sc_read)(dev, DS1553_OFF_CONTROL) | DS1553_BIT_WRITE;
           (*sc->sc_write)(dev, DS1553_OFF_CONTROL, control);
   
           (*sc->sc_write)(dev, DS1553_OFF_SECONDS, TOBCD(ct.sec) &
               DS1553_MASK_SECONDS);
           (*sc->sc_write)(dev, DS1553_OFF_MINUTES, TOBCD(ct.min) &
               DS1553_MASK_MINUTES);
           (*sc->sc_write)(dev, DS1553_OFF_HOURS, TOBCD(ct.hour) &
               DS1553_MASK_HOUR);
           (*sc->sc_write)(dev, DS1553_OFF_DAYOFWEEK, TOBCD(ct.dow + 1) &
               DS1553_MASK_DAYOFWEEK);
           (*sc->sc_write)(dev, DS1553_OFF_DATE, TOBCD(ct.day) &
               DS1553_MASK_DATE);
           (*sc->sc_write)(dev, DS1553_OFF_MONTH, TOBCD(ct.mon) &
               DS1553_MASK_MONTH);
           (*sc->sc_write)(dev, DS1553_OFF_YEAR, TOBCD(ct.year));
   
           /* Resume updates to external registers */
           control &= ~DS1553_BIT_WRITE;
           (*sc->sc_write)(dev, DS1553_OFF_CONTROL, control);
   
           mtx_unlock_spin(&sc->sc_mtx);
   
           return (0);
   }
   
   static uint8_t
   ds1553_direct_read(device_t dev, bus_size_t off)
   {
           struct ds1553_softc *sc;
   
           sc = device_get_softc(dev);
           return (bus_space_read_1(sc->sc_bst, sc->sc_bsh, off));
   }
   
   static void
   ds1553_direct_write(device_t dev, bus_size_t off, uint8_t val)
   {
           struct ds1553_softc *sc;
   
           sc = device_get_softc(dev);
           bus_space_write_1(sc->sc_bst, sc->sc_bsh, off, val);
   }

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