FreeBSD/Linux Kernel Cross Reference
sys/dev/acpica/acpi_hpet.c

     /*-
      * Copyright (c) 2005 Poul-Henning Kamp
      * 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 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.
     */
    
    #include <sys/cdefs.h>
    __FBSDID("$FreeBSD$");
    
    #include "opt_acpi.h"
    #include <sys/param.h>
    #include <sys/bus.h>
    #include <sys/kernel.h>
    #include <sys/module.h>
    #include <sys/rman.h>
    #include <sys/time.h>
    #include <sys/timetc.h>
    
    #include <contrib/dev/acpica/acpi.h>
    #include <dev/acpica/acpivar.h>
    #include <dev/acpica/acpi_hpet.h>
    
    ACPI_SERIAL_DECL(hpet, "ACPI HPET support");
    
    static devclass_t acpi_hpet_devclass;
    
    /* ACPI CA debugging */
    #define _COMPONENT      ACPI_TIMER
    ACPI_MODULE_NAME("HPET")
    
    struct acpi_hpet_softc {
            device_t                dev;
            struct resource         *mem_res;
            ACPI_HANDLE             handle;
    };
    
    static u_int hpet_get_timecount(struct timecounter *tc);
    static void acpi_hpet_test(struct acpi_hpet_softc *sc);
    
    static char *hpet_ids[] = { "PNP0103", NULL };
    
    #define DEV_HPET(x)     (acpi_get_magic(x) == (uintptr_t)&acpi_hpet_devclass)
    
    struct timecounter hpet_timecounter = {
            .tc_get_timecount =     hpet_get_timecount,
            .tc_counter_mask =      ~0u,
            .tc_name =              "HPET",
            .tc_quality =           900,
    };
    
    static u_int
    hpet_get_timecount(struct timecounter *tc)
    {
            struct acpi_hpet_softc *sc;
    
            sc = tc->tc_priv;
            return (bus_read_4(sc->mem_res, HPET_MAIN_COUNTER));
    }
    
    static void
    hpet_enable(struct acpi_hpet_softc *sc)
    {
            uint32_t val;
    
            val = bus_read_4(sc->mem_res, HPET_CONFIG);
            val &= ~HPET_CNF_LEG_RT;
            val |= HPET_CNF_ENABLE;
            bus_write_4(sc->mem_res, HPET_CONFIG, val);
    }
    
    static void
    hpet_disable(struct acpi_hpet_softc *sc)
    {
            uint32_t val;
    
            val = bus_read_4(sc->mem_res, HPET_CONFIG);
            val &= ~HPET_CNF_ENABLE;
            bus_write_4(sc->mem_res, HPET_CONFIG, val);
    }
   
   /* Discover the HPET via the ACPI table of the same name. */
   static void 
   acpi_hpet_identify(driver_t *driver, device_t parent)
   {
           ACPI_TABLE_HPET *hpet;
           ACPI_TABLE_HEADER *hdr;
           ACPI_STATUS     status;
           device_t        child;
   
           /* Only one HPET device can be added. */
           if (devclass_get_device(acpi_hpet_devclass, 0))
                   return;
   
           /* Currently, ID and minimum clock tick info is unused. */
   
           status = AcpiGetTable(ACPI_SIG_HPET, 1, (ACPI_TABLE_HEADER **)&hdr);
           if (ACPI_FAILURE(status))
                   return;
   
           /*
            * The unit number could be derived from hdr->Sequence but we only
            * support one HPET device.
            */
           hpet = (ACPI_TABLE_HPET *)hdr;
           if (hpet->Sequence != 0)
                   printf("ACPI HPET table warning: Sequence is non-zero (%d)\n",
                       hpet->Sequence);
           child = BUS_ADD_CHILD(parent, ACPI_DEV_BASE_ORDER, "acpi_hpet", 0);
           if (child == NULL) {
                   printf("%s: can't add child\n", __func__);
                   return;
           }
   
           /* Record a magic value so we can detect this device later. */
           acpi_set_magic(child, (uintptr_t)&acpi_hpet_devclass);
           bus_set_resource(child, SYS_RES_MEMORY, 0, hpet->Address.Address,
               HPET_MEM_WIDTH);
   }
   
   static int
   acpi_hpet_probe(device_t dev)
   {
           ACPI_FUNCTION_TRACE((char *)(uintptr_t) __func__);
   
           if (acpi_disabled("hpet"))
                   return (ENXIO);
           if (!DEV_HPET(dev) &&
               (ACPI_ID_PROBE(device_get_parent(dev), dev, hpet_ids) == NULL ||
               device_get_unit(dev) != 0))
                   return (ENXIO);
   
           device_set_desc(dev, "High Precision Event Timer");
           return (0);
   }
   
   static int
   acpi_hpet_attach(device_t dev)
   {
           struct acpi_hpet_softc *sc;
           int rid;
           uint32_t val, val2;
           uintmax_t freq;
   
           ACPI_FUNCTION_TRACE((char *)(uintptr_t) __func__);
   
           sc = device_get_softc(dev);
           sc->dev = dev;
           sc->handle = acpi_get_handle(dev);
   
           rid = 0;
           sc->mem_res = bus_alloc_resource_any(dev, SYS_RES_MEMORY, &rid,
               RF_ACTIVE);
           if (sc->mem_res == NULL)
                   return (ENOMEM);
   
           /* Validate that we can access the whole region. */
           if (rman_get_size(sc->mem_res) < HPET_MEM_WIDTH) {
                   device_printf(dev, "memory region width %ld too small\n",
                       rman_get_size(sc->mem_res));
                   bus_free_resource(dev, SYS_RES_MEMORY, sc->mem_res);
                   return (ENXIO);
           }
   
           /* Be sure timer is enabled. */
           hpet_enable(sc);
   
           /* Read basic statistics about the timer. */
           val = bus_read_4(sc->mem_res, HPET_PERIOD);
           if (val == 0) {
                   device_printf(dev, "invalid period\n");
                   hpet_disable(sc);
                   bus_free_resource(dev, SYS_RES_MEMORY, sc->mem_res);
                   return (ENXIO);
           }
   
           freq = (1000000000000000LL + val / 2) / val;
           if (bootverbose) {
                   val = bus_read_4(sc->mem_res, HPET_CAPABILITIES);
                   device_printf(dev,
                       "vend: 0x%x rev: 0x%x num: %d hz: %jd opts:%s%s\n",
                       val >> 16, val & HPET_CAP_REV_ID,
                       (val & HPET_CAP_NUM_TIM) >> 8, freq,
                       (val & HPET_CAP_LEG_RT) ? " legacy_route" : "",
                       (val & HPET_CAP_COUNT_SIZE) ? " 64-bit" : "");
           }
   
           if (testenv("debug.acpi.hpet_test"))
                   acpi_hpet_test(sc);
   
           /*
            * Don't attach if the timer never increments.  Since the spec
            * requires it to be at least 10 MHz, it has to change in 1 us.
            */
           val = bus_read_4(sc->mem_res, HPET_MAIN_COUNTER);
           DELAY(1);
           val2 = bus_read_4(sc->mem_res, HPET_MAIN_COUNTER);
           if (val == val2) {
                   device_printf(dev, "HPET never increments, disabling\n");
                   hpet_disable(sc);
                   bus_free_resource(dev, SYS_RES_MEMORY, sc->mem_res);
                   return (ENXIO);
           }
   
           hpet_timecounter.tc_frequency = freq;
           hpet_timecounter.tc_priv = sc;
           tc_init(&hpet_timecounter);
   
           return (0);
   }
   
   static int
   acpi_hpet_detach(device_t dev)
   {
           ACPI_FUNCTION_TRACE((char *)(uintptr_t) __func__);
   
           /* XXX Without a tc_remove() function, we can't detach. */
           return (EBUSY);
   }
   
   static int
   acpi_hpet_suspend(device_t dev)
   {
           struct acpi_hpet_softc *sc;
   
           /*
            * Disable the timer during suspend.  The timer will not lose
            * its state in S1 or S2, but we are required to disable
            * it.
            */
           sc = device_get_softc(dev);
           hpet_disable(sc);
   
           return (0);
   }
   
   static int
   acpi_hpet_resume(device_t dev)
   {
           struct acpi_hpet_softc *sc;
   
           /* Re-enable the timer after a resume to keep the clock advancing. */
           sc = device_get_softc(dev);
           hpet_enable(sc);
   
           return (0);
   }
   
   /* Print some basic latency/rate information to assist in debugging. */
   static void
   acpi_hpet_test(struct acpi_hpet_softc *sc)
   {
           int i;
           uint32_t u1, u2;
           struct bintime b0, b1, b2;
           struct timespec ts;
   
           binuptime(&b0);
           binuptime(&b0);
           binuptime(&b1);
           u1 = bus_read_4(sc->mem_res, HPET_MAIN_COUNTER);
           for (i = 1; i < 1000; i++)
                   u2 = bus_read_4(sc->mem_res, HPET_MAIN_COUNTER);
           binuptime(&b2);
           u2 = bus_read_4(sc->mem_res, HPET_MAIN_COUNTER);
   
           bintime_sub(&b2, &b1);
           bintime_sub(&b1, &b0);
           bintime_sub(&b2, &b1);
           bintime2timespec(&b2, &ts);
   
           device_printf(sc->dev, "%ld.%09ld: %u ... %u = %u\n",
               (long)ts.tv_sec, ts.tv_nsec, u1, u2, u2 - u1);
   
           device_printf(sc->dev, "time per call: %ld ns\n", ts.tv_nsec / 1000);
   }
   
   static device_method_t acpi_hpet_methods[] = {
           /* Device interface */
           DEVMETHOD(device_identify, acpi_hpet_identify),
           DEVMETHOD(device_probe, acpi_hpet_probe),
           DEVMETHOD(device_attach, acpi_hpet_attach),
           DEVMETHOD(device_detach, acpi_hpet_detach),
           DEVMETHOD(device_suspend, acpi_hpet_suspend),
           DEVMETHOD(device_resume, acpi_hpet_resume),
   
           {0, 0}
   };
   
   static driver_t acpi_hpet_driver = {
           "acpi_hpet",
           acpi_hpet_methods,
           sizeof(struct acpi_hpet_softc),
   };
   
   
   DRIVER_MODULE(acpi_hpet, acpi, acpi_hpet_driver, acpi_hpet_devclass, 0, 0);
   MODULE_DEPEND(acpi_hpet, acpi, 1, 1, 1);

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