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/*-
* Copyright (c) 2009 Gallon Sylvestre. All rights reserved.
* Copyright (c) 2010 Greg Ansley. 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 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 "opt_platform.h"
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/bus.h>
#include <sys/kernel.h>
#include <sys/module.h>
#include <sys/resource.h>
#include <sys/systm.h>
#include <sys/rman.h>
#include <sys/time.h>
#include <sys/timetc.h>
#include <sys/watchdog.h>
#include <machine/bus.h>
#include <machine/cpu.h>
#include <machine/cpufunc.h>
#include <machine/frame.h>
#include <machine/intr.h>
#include <machine/resource.h>
#include <arm/at91/at91var.h>
#include <arm/at91/at91_pitreg.h>
#ifdef FDT
#include <dev/fdt/fdt_common.h>
#include <dev/ofw/ofw_bus.h>
#include <dev/ofw/ofw_bus_subr.h>
#endif
#ifndef PIT_PRESCALE
#define PIT_PRESCALE (16)
#endif
static struct pit_softc {
struct resource *mem_res; /* Memory resource */
void *intrhand; /* Interrupt handle */
device_t sc_dev;
} *sc;
static uint32_t timecount = 0;
static unsigned at91_pit_get_timecount(struct timecounter *tc);
static int pit_intr(void *arg);
static inline uint32_t
RD4(struct pit_softc *sc, bus_size_t off)
{
return (bus_read_4(sc->mem_res, off));
}
static inline void
WR4(struct pit_softc *sc, bus_size_t off, uint32_t val)
{
bus_write_4(sc->mem_res, off, val);
}
void
at91_pit_delay(int us)
{
int32_t cnt, last, piv;
uint64_t pit_freq;
const uint64_t mhz = 1E6;
if (sc == NULL)
return;
last = PIT_PIV(RD4(sc, PIT_PIIR));
/* Max delay ~= 260s. @ 133Mhz */
pit_freq = at91_master_clock / PIT_PRESCALE;
cnt = ((pit_freq * us) + (mhz -1)) / mhz;
cnt = (cnt <= 0) ? 1 : cnt;
while (cnt > 0) {
piv = PIT_PIV(RD4(sc, PIT_PIIR));
cnt -= piv - last ;
if (piv < last)
cnt -= PIT_PIV(~0u) - last;
last = piv;
}
}
static struct timecounter at91_pit_timecounter = {
at91_pit_get_timecount, /* get_timecount */
NULL, /* no poll_pps */
0xffffffff, /* counter mask */
0 / PIT_PRESCALE, /* frequency */
"AT91SAM9 timer", /* name */
1000 /* quality */
};
static int
at91_pit_probe(device_t dev)
{
#ifdef FDT
if (!ofw_bus_is_compatible(dev, "atmel,at91sam9260-pit"))
return (ENXIO);
#endif
device_set_desc(dev, "AT91SAM9 PIT");
return (0);
}
static int
at91_pit_attach(device_t dev)
{
void *ih;
int rid, err = 0;
struct resource *irq;
sc = device_get_softc(dev);
sc->sc_dev = dev;
rid = 0;
sc->mem_res = bus_alloc_resource_any(dev, SYS_RES_MEMORY, &rid,
RF_ACTIVE);
if (sc->mem_res == NULL)
panic("couldn't allocate register resources");
rid = 0;
irq = bus_alloc_resource(dev, SYS_RES_IRQ, &rid, 1, 1, 1,
RF_ACTIVE | RF_SHAREABLE);
if (!irq) {
device_printf(dev, "could not allocate interrupt resources.\n");
err = ENOMEM;
goto out;
}
/* Activate the interrupt. */
err = bus_setup_intr(dev, irq, INTR_TYPE_CLK, pit_intr, NULL, NULL,
&ih);
at91_pit_timecounter.tc_frequency = at91_master_clock / PIT_PRESCALE;
tc_init(&at91_pit_timecounter);
/* Enable the PIT here. */
WR4(sc, PIT_MR, PIT_PIV(at91_master_clock / PIT_PRESCALE / hz) |
PIT_EN | PIT_IEN);
out:
return (err);
}
static int
pit_intr(void *arg)
{
struct trapframe *fp = arg;
uint32_t icnt;
if (RD4(sc, PIT_SR) & PIT_PITS_DONE) {
icnt = RD4(sc, PIT_PIVR) >> 20;
/* Just add in the overflows we just read */
timecount += PIT_PIV(RD4(sc, PIT_MR)) * icnt;
hardclock(TRAPF_USERMODE(fp), TRAPF_PC(fp));
return (FILTER_HANDLED);
}
return (FILTER_STRAY);
}
static unsigned
at91_pit_get_timecount(struct timecounter *tc)
{
uint32_t piir, icnt;
piir = RD4(sc, PIT_PIIR); /* Current count | over flows */
icnt = piir >> 20; /* Overflows */
return (timecount + PIT_PIV(piir) + PIT_PIV(RD4(sc, PIT_MR)) * icnt);
}
static device_method_t at91_pit_methods[] = {
DEVMETHOD(device_probe, at91_pit_probe),
DEVMETHOD(device_attach, at91_pit_attach),
DEVMETHOD_END
};
static driver_t at91_pit_driver = {
"at91_pit",
at91_pit_methods,
sizeof(struct pit_softc),
};
static devclass_t at91_pit_devclass;
#ifdef FDT
EARLY_DRIVER_MODULE(at91_pit, simplebus, at91_pit_driver, at91_pit_devclass,
NULL, NULL, BUS_PASS_TIMER);
#else
EARLY_DRIVER_MODULE(at91_pit, atmelarm, at91_pit_driver, at91_pit_devclass,
NULL, NULL, BUS_PASS_TIMER);
#endif
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