FreeBSD/Linux Kernel Cross Reference
sys/sparc64/sparc64/counter.c

     /*-
      * Copyright (c) 2002 by Thomas Moestl <tmm@FreeBSD.org>.
      * 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 ``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 THE 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.
     *
     * $FreeBSD$
     */
    
    #include <sys/param.h>
    #include <sys/bus.h>
    #include <sys/malloc.h>
    #include <sys/systm.h>
    #include <sys/time.h>
    #include <sys/timetc.h>
    
    #include <machine/bus.h>
    #include <machine/bus_common.h>
    
    #define COUNTER_MASK    ((1 << 29) - 1)
    #define COUNTER_FREQ    1000000
    #define COUNTER_QUALITY 100
    
    /* Bits in the limit register. */
    #define CTLR_INTEN      (1U << 31)      /* Enable timer interrupts */
    #define CTLR_RELOAD     (1U << 30)      /* Zero counter on write to limit reg */
    #define CTLR_PERIODIC   (1U << 29)      /* Wrap to 0 if limit is reached */
    
    /* Offsets of the registers for the two counters. */
    #define CTR_CT0         0x00
    #define CTR_CT1         0x10
    
    /* Register offsets from the base address. */
    #define CTR_COUNT       0x00
    #define CTR_LIMIT       0x08
    
    
    static unsigned int counter_get_timecount(struct timecounter *tc);
    
    struct ct_softc {
            bus_space_tag_t         sc_tag;
            bus_space_handle_t      sc_handle;
            bus_addr_t              sc_offset;
    };
    
    
    /*
     * This is called from the psycho and sbus drivers. It does not directly attach
     * to the nexus because it shares register space with the bridge in question.
     */
    void
    sparc64_counter_init(bus_space_tag_t tag, bus_space_handle_t handle,
        bus_addr_t offset)
    {
            struct timecounter *tc;
            struct ct_softc *sc;
    
            printf("initializing counter-timer\n");
            /*
             * Turn off interrupts from both counters. Set the limit to the maximum
             * value (although that should not change anything with CTLR_INTEN and
             * CTLR_PERIODIC off).
             */
            bus_space_write_8(tag, handle, offset + CTR_CT0 + CTR_LIMIT,
                COUNTER_MASK);
            bus_space_write_8(tag, handle, offset + CTR_CT1 + CTR_LIMIT,
                COUNTER_MASK);
            /* Register as a time counter. */
            tc = malloc(sizeof(*tc), M_DEVBUF, M_WAITOK);
            sc = malloc(sizeof(*sc), M_DEVBUF, M_WAITOK);
            sc->sc_tag = tag;
            sc->sc_handle = handle;
            sc->sc_offset = offset + CTR_CT0;
            tc->tc_get_timecount = counter_get_timecount;
            tc->tc_poll_pps = NULL;
            tc->tc_counter_mask = COUNTER_MASK;
            tc->tc_frequency = COUNTER_FREQ;
            tc->tc_name = "counter-timer";
            tc->tc_priv = sc;
            tc->tc_quality = COUNTER_QUALITY;
            tc_init(tc);
   }
   
   static unsigned int
   counter_get_timecount(struct timecounter *tc)
   {
           struct ct_softc *sc;
   
           sc = tc->tc_priv;
           return (bus_space_read_8(sc->sc_tag, sc->sc_handle, sc->sc_offset) &
               COUNTER_MASK);
   }

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