freebsd-nq/sys/arm/samsung/exynos/exynos5_mct.c

140 lines
3.7 KiB
C

/*-
* Copyright (c) 2013 Ruslan Bukin <br@bsdpad.com>
* 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.
*/
/*
* This module just enables Exynos MCT, so ARMv7 Generic Timer will works
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/bus.h>
#include <sys/kernel.h>
#include <sys/module.h>
#include <sys/malloc.h>
#include <sys/rman.h>
#include <sys/timeet.h>
#include <sys/timetc.h>
#include <sys/watchdog.h>
#include <machine/bus.h>
#include <machine/cpu.h>
#include <machine/intr.h>
#include <dev/fdt/fdt_common.h>
#include <dev/ofw/openfirm.h>
#include <dev/ofw/ofw_bus.h>
#include <dev/ofw/ofw_bus_subr.h>
#include <machine/bus.h>
#include <machine/fdt.h>
#define MCT_CTRL_START (1 << 8)
#define MCT_CTRL (0x240)
#define MCT_WRITE_STAT (0x24C)
struct arm_tmr_softc {
struct resource *tmr_res[1];
bus_space_tag_t bst;
bus_space_handle_t bsh;
};
static struct resource_spec arm_tmr_spec[] = {
{ SYS_RES_MEMORY, 0, RF_ACTIVE }, /* Timer registers */
{ -1, 0 }
};
static int
arm_tmr_probe(device_t dev)
{
if (!ofw_bus_status_okay(dev))
return (ENXIO);
if (!ofw_bus_is_compatible(dev, "exynos,mct"))
return (ENXIO);
device_set_desc(dev, "Exynos MPCore Timer");
return (BUS_PROBE_DEFAULT);
}
static int
arm_tmr_attach(device_t dev)
{
struct arm_tmr_softc *sc;
int reg, i;
int mask;
sc = device_get_softc(dev);
if (bus_alloc_resources(dev, arm_tmr_spec, sc->tmr_res)) {
device_printf(dev, "could not allocate resources\n");
return (ENXIO);
}
/* Timer interface */
sc->bst = rman_get_bustag(sc->tmr_res[0]);
sc->bsh = rman_get_bushandle(sc->tmr_res[0]);
reg = bus_space_read_4(sc->bst, sc->bsh, MCT_CTRL);
reg |= MCT_CTRL_START;
bus_space_write_4(sc->bst, sc->bsh, MCT_CTRL, reg);
mask = (1 << 16);
/* Wait 10 times until written value is applied */
for (i = 0; i < 10; i++) {
reg = bus_space_read_4(sc->bst, sc->bsh, MCT_WRITE_STAT);
if (reg & mask) {
bus_space_write_4(sc->bst, sc->bsh,
MCT_WRITE_STAT, mask);
return (0);
}
cpufunc_nullop();
}
/* NOTREACHED */
panic("Can't enable timer\n");
}
static device_method_t arm_tmr_methods[] = {
DEVMETHOD(device_probe, arm_tmr_probe),
DEVMETHOD(device_attach, arm_tmr_attach),
{ 0, 0 }
};
static driver_t arm_tmr_driver = {
"mct",
arm_tmr_methods,
sizeof(struct arm_tmr_softc),
};
static devclass_t arm_tmr_devclass;
DRIVER_MODULE(mct, simplebus, arm_tmr_driver, arm_tmr_devclass, 0, 0);