freebsd-skq/sys/arm/at91/at91_st.c
imp 515d0c1d29 Make the SoC stuff a little more modular, and start to move away from
having the CPU device that's a child of atmelarm that does stuff.

o Create a linker_set for the support fucntions for the SoCs.
o Rename soc_data to soc_info.
o Move the delay and reset function pointers to new soc_data struct
o Create elements for all known SoCs
o Add lookup of the SoC we found, and print a warning if it isn't one
  we know about.
2012-07-11 20:17:14 +00:00

314 lines
7.5 KiB
C

/*-
* Copyright (c) 2005 Olivier Houchard. 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 <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/module.h>
#include <sys/time.h>
#include <sys/bus.h>
#include <sys/resource.h>
#include <sys/rman.h>
#include <sys/timetc.h>
#include <sys/watchdog.h>
#include <machine/bus.h>
#include <machine/cpu.h>
#include <machine/cpufunc.h>
#include <machine/resource.h>
#include <machine/frame.h>
#include <machine/intr.h>
#include <arm/at91/at91var.h>
#include <arm/at91/at91_streg.h>
#include <arm/at91/at91rm92reg.h>
static struct at91_st_softc {
struct resource * sc_irq_res;
struct resource * sc_mem_res;
void * sc_intrhand;
eventhandler_tag sc_wet; /* watchdog event handler tag */
} *timer_softc;
static inline uint32_t
RD4(bus_size_t off)
{
if (timer_softc == NULL) {
uint32_t *p = (uint32_t *)(AT91_BASE + AT91RM92_ST_BASE + off);
return *p;
}
return (bus_read_4(timer_softc->sc_mem_res, off));
}
static inline void
WR4(bus_size_t off, uint32_t val)
{
if (timer_softc == NULL) {
uint32_t *p = (uint32_t *)(AT91_BASE + AT91RM92_ST_BASE + off);
*p = val;
}
else
bus_write_4(timer_softc->sc_mem_res, off, val);
}
static void at91_st_watchdog(void *, u_int, int *);
static void at91_st_initclocks(device_t , struct at91_st_softc *);
static inline int
st_crtr(void)
{
int cur1, cur2;
do {
cur1 = RD4(ST_CRTR);
cur2 = RD4(ST_CRTR);
} while (cur1 != cur2);
return (cur1);
}
static unsigned at91_st_get_timecount(struct timecounter *tc);
static struct timecounter at91_st_timecounter = {
at91_st_get_timecount, /* get_timecount */
NULL, /* no poll_pps */
0xfffffu, /* counter_mask */
32768, /* frequency */
"AT91RM9200 timer", /* name */
1000 /* quality */
};
static int
clock_intr(void *arg)
{
struct trapframe *fp = arg;
/* The interrupt is shared, so we have to make sure it's for us. */
if (RD4(ST_SR) & ST_SR_PITS) {
hardclock(TRAPF_USERMODE(fp), TRAPF_PC(fp));
return (FILTER_HANDLED);
}
return (FILTER_STRAY);
}
void
at91_st_delay(int n)
{
uint32_t start, end, cur;
start = st_crtr();
n = (n * 1000) / 32768;
if (n <= 0)
n = 1;
end = (start + n) & ST_CRTR_MASK;
cur = start;
if (start > end) {
while (cur >= start || cur < end)
cur = st_crtr();
} else {
while (cur < end)
cur = st_crtr();
}
}
void
at91_st_cpu_reset(void)
{
/*
* Reset the CPU by programmig the watchdog timer to reset the
* CPU after 128 'slow' clocks, or about ~4ms. Loop until
* the reset happens for safety.
*/
WR4(ST_WDMR, ST_WDMR_RSTEN | 2);
WR4(ST_CR, ST_CR_WDRST);
while (1)
continue;
}
static int
at91_st_probe(device_t dev)
{
device_set_desc(dev, "ST");
return (0);
}
static void
at91_st_deactivate(device_t dev)
{
struct at91_st_softc *sc = timer_softc;
if (sc->sc_intrhand)
bus_teardown_intr(dev, sc->sc_irq_res, sc->sc_intrhand);
sc->sc_intrhand = NULL;
if (sc->sc_irq_res)
bus_release_resource(dev, SYS_RES_IRQ,
rman_get_rid(sc->sc_irq_res), sc->sc_irq_res);
sc->sc_irq_res = NULL;
if (sc->sc_mem_res)
bus_release_resource(dev, SYS_RES_MEMORY,
rman_get_rid(sc->sc_mem_res), sc->sc_mem_res);
sc->sc_mem_res = NULL;
}
static int
at91_st_activate(device_t dev)
{
int rid;
int err;
struct at91_st_softc *sc = timer_softc;
rid = 0;
sc->sc_mem_res = bus_alloc_resource_any(dev, SYS_RES_MEMORY, &rid,
RF_ACTIVE);
err = ENOMEM;
if (sc->sc_mem_res == NULL)
goto out;
/* Disable all interrupts */
WR4(ST_IDR, 0xffffffff);
/* The system timer shares the system irq (1) */
rid = 0;
sc->sc_irq_res = bus_alloc_resource_any(dev, SYS_RES_IRQ, &rid,
RF_ACTIVE | RF_SHAREABLE);
if (sc->sc_irq_res == NULL) {
printf("Unable to allocate irq for the system timer");
goto out;
}
err = bus_setup_intr(dev, sc->sc_irq_res, INTR_TYPE_CLK, clock_intr,
NULL, NULL, &sc->sc_intrhand);
out:
if (err != 0)
at91_st_deactivate(dev);
return (err);
}
static int
at91_st_attach(device_t dev)
{
int err;
timer_softc = device_get_softc(dev);
err = at91_st_activate(dev);
if (err)
return err;
timer_softc->sc_wet = EVENTHANDLER_REGISTER(watchdog_list,
at91_st_watchdog, dev, 0);
device_printf(dev,
"watchdog registered, timeout intervall max. 64 sec\n");
at91_st_initclocks(dev, timer_softc);
return (0);
}
static device_method_t at91_st_methods[] = {
DEVMETHOD(device_probe, at91_st_probe),
DEVMETHOD(device_attach, at91_st_attach),
{0, 0},
};
static driver_t at91_st_driver = {
"at91_st",
at91_st_methods,
sizeof(struct at91_st_softc),
};
static devclass_t at91_st_devclass;
DRIVER_MODULE(at91_st, atmelarm, at91_st_driver, at91_st_devclass, 0, 0);
static unsigned
at91_st_get_timecount(struct timecounter *tc)
{
return (st_crtr());
}
/*
* t below is in a weird unit. The watchdog is set to 2^t
* nanoseconds. Since our watchdog timer can't really do that too
* well, we approximate it by assuming that the timeout interval for
* the lsb is 2^22 ns, which is 4.194ms. This is an overestimation of
* the actual time (3.906ms), but close enough for watchdogging.
* These approximations, though a violation of the spec, improve the
* performance of the application which typically specifies things as
* WD_TO_32SEC. In that last case, we'd wait 32s before the wdog
* reset. The spec says we should wait closer to 34s, but given how
* it is likely to be used, and the extremely coarse nature time
* interval, I think this is the best solution.
*/
static void
at91_st_watchdog(void *argp, u_int cmd, int *error)
{
uint32_t wdog;
int t;
t = cmd & WD_INTERVAL;
if (t >= 22 && t <= 37) {
wdog = (1 << (t - 22)) | ST_WDMR_RSTEN;
*error = 0;
} else {
wdog = 0;
}
WR4(ST_WDMR, wdog);
WR4(ST_CR, ST_CR_WDRST);
}
static void
at91_st_initclocks(device_t dev, struct at91_st_softc *sc)
{
int rel_value;
/*
* Real time counter increments every clock cycle, need to set before
* initializing clocks so that DELAY works.
*/
WR4(ST_RTMR, 1);
/* disable watchdog timer */
WR4(ST_WDMR, 0);
rel_value = 32768 / hz;
if (rel_value < 1)
rel_value = 1;
if (32768 % hz) {
device_printf(dev, "Cannot get %d Hz clock; using %dHz\n", hz,
32768 / rel_value);
hz = 32768 / rel_value;
tick = 1000000 / hz;
}
WR4(ST_PIMR, rel_value);
/* Enable PITS interrupts. */
WR4(ST_IER, ST_SR_PITS);
tc_init(&at91_st_timecounter);
}