freebsd-skq/sys/arm/at91/at91_rst.c

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/*-
* 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 <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/bus.h>
#include <sys/kernel.h>
#include <sys/module.h>
#include <sys/rman.h>
#include <sys/systm.h>
#include <machine/bus.h>
#include <arm/at91/at91var.h>
#include <arm/at91/at91_rstreg.h>
#include <arm/at91/at91board.h>
#define RST_TIMEOUT (5) /* Seconds to hold NRST for hard reset */
#define RST_TICK (20) /* sample NRST at hz/RST_TICK intervals */
static int rst_intr(void *arg);
static struct rst_softc {
struct resource *mem_res; /* Memory resource */
struct resource *irq_res; /* IRQ resource */
void *intrhand; /* Interrupt handle */
struct callout tick_ch; /* Tick callout */
device_t sc_dev;
u_int shutdown; /* Shutdown in progress */
} *rst_sc;
static inline uint32_t
RD4(struct rst_softc *sc, bus_size_t off)
{
return (bus_read_4(sc->mem_res, off));
}
static inline void
WR4(struct rst_softc *sc, bus_size_t off, uint32_t val)
{
bus_write_4(sc->mem_res, off, val);
}
static int
at91_rst_probe(device_t dev)
{
if (at91_is_sam9()) {
device_set_desc(dev, "AT91SAM9 Reset Controller");
return (0);
}
return (ENXIO);
}
static int
at91_rst_attach(device_t dev)
{
struct rst_softc *sc;
const char *cause;
int rid, err;
rst_sc = sc = device_get_softc(dev);
sc->sc_dev = dev;
callout_init(&sc->tick_ch, 0);
rid = 0;
sc->mem_res = bus_alloc_resource_any(dev, SYS_RES_MEMORY, &rid,
RF_ACTIVE);
if (sc->mem_res == NULL) {
device_printf(dev, "could not allocate memory resources.\n");
err = ENOMEM;
goto out;
}
rid = 0;
sc->irq_res = bus_alloc_resource_any(dev, SYS_RES_IRQ, &rid,
RF_ACTIVE | RF_SHAREABLE);
if (sc->irq_res == NULL) {
device_printf(dev, "could not allocate interrupt resources.\n");
err = ENOMEM;
goto out;
}
/* Activate the interrupt. */
err = bus_setup_intr(dev, sc->irq_res, INTR_TYPE_MISC | INTR_MPSAFE,
rst_intr, NULL, sc, &sc->intrhand);
if (err)
device_printf(dev, "could not establish interrupt handler.\n");
WR4(rst_sc, RST_MR, RST_MR_ERSTL(0xd) | RST_MR_URSIEN | RST_MR_KEY);
switch (RD4(sc, RST_SR) & RST_SR_RST_MASK) {
case RST_SR_RST_POW:
cause = "Power On";
break;
case RST_SR_RST_WAKE:
cause = "Wake Up";
break;
case RST_SR_RST_WDT:
cause = "Watchdog";
break;
case RST_SR_RST_SOFT:
cause = "Software Request";
break;
case RST_SR_RST_USR:
cause = "External (User)";
break;
default:
cause = "Unknown";
break;
}
device_printf(dev, "Reset cause: %s.\n", cause);
/* cpu_reset_addr = cpu_reset; */
out:
return (err);
}
static void
rst_tick(void *argp)
{
struct rst_softc *sc = argp;
if (sc->shutdown++ >= RST_TIMEOUT * RST_TICK) {
/* User released the button in morre than RST_TIMEOUT */
cpu_reset();
} else if ((RD4(sc, RST_SR) & RST_SR_NRSTL)) {
/* User released the button in less than RST_TIMEOUT */
sc->shutdown = 0;
device_printf(sc->sc_dev, "shutting down...\n");
shutdown_nice(0);
} else {
callout_reset(&sc->tick_ch, hz/RST_TICK, rst_tick, sc);
}
}
static int
rst_intr(void *argp)
{
struct rst_softc *sc = argp;
if (RD4(sc, RST_SR) & RST_SR_URSTS) {
if (sc->shutdown == 0)
callout_reset(&sc->tick_ch, hz/RST_TICK, rst_tick, sc);
return (FILTER_HANDLED);
}
return (FILTER_STRAY);
}
static device_method_t at91_rst_methods[] = {
DEVMETHOD(device_probe, at91_rst_probe),
DEVMETHOD(device_attach, at91_rst_attach),
{0,0},
};
static driver_t at91_rst_driver = {
"at91_rst",
at91_rst_methods,
sizeof(struct rst_softc),
};
static devclass_t at91_rst_devclass;
DRIVER_MODULE(at91_rst, atmelarm, at91_rst_driver, at91_rst_devclass, 0, 0);
void cpu_reset_sam9g20(void) __attribute__((weak));
void cpu_reset_sam9g20(void) {}
void
cpu_reset(void)
{
if (rst_sc) {
cpu_reset_sam9g20(); /* May be null */
WR4(rst_sc, RST_MR,
RST_MR_ERSTL(0xd) | RST_MR_URSTEN | RST_MR_KEY);
WR4(rst_sc, RST_CR,
RST_CR_PROCRST |
RST_CR_PERRST |
RST_CR_EXTRST |
RST_CR_KEY);
}
for(;;) ;
}