/*-
* Copyright (c) 2011 Jakub Wojciech Klama <jceel@FreeBSD.org>
* 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 <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/timetc.h>
#include <sys/timeet.h>
#include <machine/bus.h>
#include <machine/cpu.h>
#include <machine/intr.h>
#include <dev/ofw/ofw_bus.h>
#include <dev/ofw/ofw_bus_subr.h>
#include <arm/lpc/lpcreg.h>
#include <arm/lpc/lpcvar.h>
struct lpc_timer_softc {
device_t lt_dev;
struct eventtimer lt_et;
struct resource * lt_res[5];
bus_space_tag_t lt_bst0;
bus_space_handle_t lt_bsh0;
bus_space_tag_t lt_bst1;
bus_space_handle_t lt_bsh1;
int lt_oneshot;
uint32_t lt_period;
};
static struct resource_spec lpc_timer_spec[] = {
{ SYS_RES_MEMORY, 0, RF_ACTIVE },
{ SYS_RES_MEMORY, 1, RF_ACTIVE },
{ SYS_RES_IRQ, 0, RF_ACTIVE },
{ SYS_RES_IRQ, 1, RF_ACTIVE },
{ -1, 0 }
};
static struct lpc_timer_softc *timer_softc = NULL;
static int lpc_timer_initialized = 0;
static int lpc_timer_probe(device_t);
static int lpc_timer_attach(device_t);
static int lpc_timer_start(struct eventtimer *,
sbintime_t first, sbintime_t period);
static int lpc_timer_stop(struct eventtimer *et);
static unsigned lpc_get_timecount(struct timecounter *);
static int lpc_hardclock(void *);
#define timer0_read_4(sc, reg) \
bus_space_read_4(sc->lt_bst0, sc->lt_bsh0, reg)
#define timer0_write_4(sc, reg, val) \
bus_space_write_4(sc->lt_bst0, sc->lt_bsh0, reg, val)
#define timer0_clear(sc) \
do { \
timer0_write_4(sc, LPC_TIMER_TC, 0); \
timer0_write_4(sc, LPC_TIMER_PR, 0); \
timer0_write_4(sc, LPC_TIMER_PC, 0); \
} while(0)
#define timer1_read_4(sc, reg) \
bus_space_read_4(sc->lt_bst1, sc->lt_bsh1, reg)
#define timer1_write_4(sc, reg, val) \
bus_space_write_4(sc->lt_bst1, sc->lt_bsh1, reg, val)
#define timer1_clear(sc) \
do { \
timer1_write_4(sc, LPC_TIMER_TC, 0); \
timer1_write_4(sc, LPC_TIMER_PR, 0); \
timer1_write_4(sc, LPC_TIMER_PC, 0); \
} while(0)
static struct timecounter lpc_timecounter = {
.tc_get_timecount = lpc_get_timecount,
.tc_name = "LPC32x0 Timer1",
.tc_frequency = 0, /* will be filled later */
.tc_counter_mask = ~0u,
.tc_quality = 1000,
};
static int
lpc_timer_probe(device_t dev)
{
if (!ofw_bus_status_okay(dev))
return (ENXIO);
if (!ofw_bus_is_compatible(dev, "lpc,timer"))
return (ENXIO);
device_set_desc(dev, "LPC32x0 timer");
return (BUS_PROBE_DEFAULT);
}
static int
lpc_timer_attach(device_t dev)
{
void *intrcookie;
struct lpc_timer_softc *sc = device_get_softc(dev);
phandle_t node;
uint32_t freq;
if (timer_softc)
return (ENXIO);
timer_softc = sc;
if (bus_alloc_resources(dev, lpc_timer_spec, sc->lt_res)) {
device_printf(dev, "could not allocate resources\n");
return (ENXIO);
}
sc->lt_bst0 = rman_get_bustag(sc->lt_res[0]);
sc->lt_bsh0 = rman_get_bushandle(sc->lt_res[0]);
sc->lt_bst1 = rman_get_bustag(sc->lt_res[1]);
sc->lt_bsh1 = rman_get_bushandle(sc->lt_res[1]);
if (bus_setup_intr(dev, sc->lt_res[2], INTR_TYPE_CLK,
lpc_hardclock, NULL, sc, &intrcookie)) {
device_printf(dev, "could not setup interrupt handler\n");
bus_release_resources(dev, lpc_timer_spec, sc->lt_res);
return (ENXIO);
}
/* Enable timer clock */
lpc_pwr_write(dev, LPC_CLKPWR_TIMCLK_CTRL1,
LPC_CLKPWR_TIMCLK_CTRL1_TIMER0 |
LPC_CLKPWR_TIMCLK_CTRL1_TIMER1);
/* Get PERIPH_CLK encoded in parent bus 'bus-frequency' property */
node = ofw_bus_get_node(dev);
if (OF_getencprop(OF_parent(node), "bus-frequency", &freq,
sizeof(pcell_t)) <= 0) {
bus_release_resources(dev, lpc_timer_spec, sc->lt_res);
bus_teardown_intr(dev, sc->lt_res[2], intrcookie);
device_printf(dev, "could not obtain base clock frequency\n");
return (ENXIO);
}
/* Set desired frequency in event timer and timecounter */
sc->lt_et.et_frequency = (uint64_t)freq;
lpc_timecounter.tc_frequency = (uint64_t)freq;
sc->lt_et.et_name = "LPC32x0 Timer0";
sc->lt_et.et_flags = ET_FLAGS_PERIODIC | ET_FLAGS_ONESHOT;
sc->lt_et.et_quality = 1000;
sc->lt_et.et_min_period = (0x00000002LLU << 32) / sc->lt_et.et_frequency;
sc->lt_et.et_max_period = (0xfffffffeLLU << 32) / sc->lt_et.et_frequency;
sc->lt_et.et_start = lpc_timer_start;
sc->lt_et.et_stop = lpc_timer_stop;
sc->lt_et.et_priv = sc;
et_register(&sc->lt_et);
tc_init(&lpc_timecounter);
/* Reset and enable timecounter */
timer1_write_4(sc, LPC_TIMER_TCR, LPC_TIMER_TCR_RESET);
timer1_write_4(sc, LPC_TIMER_TCR, 0);
timer1_clear(sc);
timer1_write_4(sc, LPC_TIMER_TCR, LPC_TIMER_TCR_ENABLE);
/* DELAY() now can work properly */
lpc_timer_initialized = 1;
return (0);
}
static int
lpc_timer_start(struct eventtimer *et, sbintime_t first, sbintime_t period)
{
struct lpc_timer_softc *sc = (struct lpc_timer_softc *)et->et_priv;
uint32_t ticks;
if (period == 0) {
sc->lt_oneshot = 1;
sc->lt_period = 0;
} else {
sc->lt_oneshot = 0;
sc->lt_period = ((uint32_t)et->et_frequency * period) >> 32;
}
if (first == 0)
ticks = sc->lt_period;
else
ticks = ((uint32_t)et->et_frequency * first) >> 32;
/* Reset timer */
timer0_write_4(sc, LPC_TIMER_TCR, LPC_TIMER_TCR_RESET);
timer0_write_4(sc, LPC_TIMER_TCR, 0);
/* Start timer */
timer0_clear(sc);
timer0_write_4(sc, LPC_TIMER_MR0, ticks);
timer0_write_4(sc, LPC_TIMER_MCR, LPC_TIMER_MCR_MR0I | LPC_TIMER_MCR_MR0S);
timer0_write_4(sc, LPC_TIMER_TCR, LPC_TIMER_TCR_ENABLE);
return (0);
}
static int
lpc_timer_stop(struct eventtimer *et)
{
struct lpc_timer_softc *sc = (struct lpc_timer_softc *)et->et_priv;
timer0_write_4(sc, LPC_TIMER_TCR, 0);
return (0);
}
static device_method_t lpc_timer_methods[] = {
DEVMETHOD(device_probe, lpc_timer_probe),
DEVMETHOD(device_attach, lpc_timer_attach),
{ 0, 0 }
};
static driver_t lpc_timer_driver = {
"timer",
lpc_timer_methods,
sizeof(struct lpc_timer_softc),
};
static devclass_t lpc_timer_devclass;
DRIVER_MODULE(timer, simplebus, lpc_timer_driver, lpc_timer_devclass, 0, 0);
static int
lpc_hardclock(void *arg)
{
struct lpc_timer_softc *sc = (struct lpc_timer_softc *)arg;
/* Reset pending interrupt */
timer0_write_4(sc, LPC_TIMER_IR, 0xffffffff);
/* Start timer again */
if (!sc->lt_oneshot) {
timer0_clear(sc);
timer0_write_4(sc, LPC_TIMER_MR0, sc->lt_period);
timer0_write_4(sc, LPC_TIMER_TCR, LPC_TIMER_TCR_ENABLE);
}
if (sc->lt_et.et_active)
sc->lt_et.et_event_cb(&sc->lt_et, sc->lt_et.et_arg);
return (FILTER_HANDLED);
}
static unsigned
lpc_get_timecount(struct timecounter *tc)
{
return timer1_read_4(timer_softc, LPC_TIMER_TC);
}
void
DELAY(int usec)
{
uint32_t counter;
uint32_t first, last;
int val = (lpc_timecounter.tc_frequency / 1000000 + 1) * usec;
/* Timer is not initialized yet */
if (!lpc_timer_initialized) {
for (; usec > 0; usec--)
for (counter = 100; counter > 0; counter--)
;
return;
}
first = lpc_get_timecount(&lpc_timecounter);
while (val > 0) {
last = lpc_get_timecount(&lpc_timecounter);
if (last < first) {
/* Timer rolled over */
last = first;
}
val -= (last - first);
first = last;
}
}
