freebsd-skq/sys/dev/acpica/acpi_hpet.c

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/*-
* 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>
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 HPET_MEM_WIDTH 0x400 /* Expected memory region size */
#define HPET_OFFSET_INFO 0 /* Location of info in region */
#define HPET_OFFSET_PERIOD 4 /* Location of period (1/hz) */
#define HPET_OFFSET_ENABLE 0x10 /* Location of enable word */
#define HPET_OFFSET_VALUE 0xf0 /* Location of actual timer value */
#define DEV_HPET(x) (acpi_get_magic(x) == (int)&acpi_hpet_devclass)
struct timecounter hpet_timecounter = {
.tc_get_timecount = hpet_get_timecount,
.tc_counter_mask = ~0u,
.tc_name = "HPET",
.tc_quality = 2000,
};
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_OFFSET_VALUE));
}
/* Discover the HPET via the ACPI table of the same name. */
void
acpi_hpet_table_probe(device_t parent)
{
ACPI_TABLE_HPET *hpet;
ACPI_TABLE_HEADER *hdr;
ACPI_STATUS status;
device_t child;
/* 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, 0, "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, (int)&acpi_hpet_devclass);
bus_set_resource(child, SYS_RES_MEMORY, 0, hpet->Address.Address,
HPET_MEM_WIDTH);
if (device_probe_and_attach(child) != 0)
device_delete_child(parent, child);
}
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;
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);
}
/* Read basic statistics about the timer. */
val = bus_read_4(sc->mem_res, HPET_OFFSET_PERIOD);
freq = (1000000000000000LL + val / 2) / val;
if (bootverbose) {
val = bus_read_4(sc->mem_res, HPET_OFFSET_INFO);
device_printf(dev,
"vend: 0x%x rev: 0x%x num: %d hz: %jd opts:%s%s\n",
val >> 16, val & 0xff, (val >> 18) & 0xf, freq,
((val >> 15) & 1) ? " leg_route" : "",
((val >> 13) & 1) ? " count_size" : "");
}
/* Be sure it is enabled. */
bus_write_4(sc->mem_res, HPET_OFFSET_ENABLE, 1);
if (testenv("debug.acpi.hpet_test"))
acpi_hpet_test(sc);
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_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);
bus_write_4(sc->mem_res, HPET_OFFSET_ENABLE, 1);
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_OFFSET_VALUE);
for (i = 1; i < 1000; i++)
u2 = bus_read_4(sc->mem_res, HPET_OFFSET_VALUE);
binuptime(&b2);
u2 = bus_read_4(sc->mem_res, HPET_OFFSET_VALUE);
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_probe, acpi_hpet_probe),
DEVMETHOD(device_attach, acpi_hpet_attach),
DEVMETHOD(device_detach, acpi_hpet_detach),
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);