freebsd-skq/sys/arm/at91/at91_pit.c
Pedro F. Giffuni af3dc4a7ca sys/arm: further adoption of SPDX licensing ID tags.
Mainly focus on files that use BSD 2-Clause license, however the tool I
was using misidentified many licenses so this was mostly a manual - error
prone - task.

The Software Package Data Exchange (SPDX) group provides a specification
to make it easier for automated tools to detect and summarize well known
opensource licenses. We are gradually adopting the specification, noting
that the tags are considered only advisory and do not, in any way,
superceed or replace the license texts.
2017-11-27 15:04:10 +00:00

223 lines
5.4 KiB
C

/*-
* SPDX-License-Identifier: BSD-2-Clause-FreeBSD
*
* 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/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/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 = howmany(pit_freq * us, 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