freebsd-skq/sys/arm/amlogic/aml8726/aml8726_wdt.c
2020-09-01 21:17:24 +00:00

306 lines
8.4 KiB
C

/*-
* Copyright 2013-2015 John Wehle <john@feith.com>
* 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.
*
*/
/*
* Amlogic aml8726 watchdog driver.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/bus.h>
#include <sys/eventhandler.h>
#include <sys/kernel.h>
#include <sys/module.h>
#include <sys/malloc.h>
#include <sys/rman.h>
#include <sys/watchdog.h>
#include <machine/bus.h>
#include <dev/ofw/ofw_bus.h>
#include <dev/ofw/ofw_bus_subr.h>
#include <arm/amlogic/aml8726/aml8726_soc.h>
struct aml8726_wdt_softc {
device_t dev;
struct resource * res[2];
struct mtx mtx;
void * ih_cookie;
};
static struct resource_spec aml8726_wdt_spec[] = {
{ SYS_RES_MEMORY, 0, RF_ACTIVE },
{ SYS_RES_IRQ, 0, RF_ACTIVE },
{ -1, 0 }
};
static struct {
uint32_t ctrl_cpu_mask;
uint32_t ctrl_en;
uint32_t term_cnt_mask;
uint32_t reset_cnt_mask;
} aml8726_wdt_soc_params;
/*
* devclass_get_device / device_get_softc could be used
* to dynamically locate this, however the wdt is a
* required device which can't be unloaded so there's
* no need for the overhead.
*/
static struct aml8726_wdt_softc *aml8726_wdt_sc = NULL;
#define AML_WDT_LOCK(sc) mtx_lock_spin(&(sc)->mtx)
#define AML_WDT_UNLOCK(sc) mtx_unlock_spin(&(sc)->mtx)
#define AML_WDT_LOCK_INIT(sc) \
mtx_init(&(sc)->mtx, device_get_nameunit((sc)->dev), \
"wdt", MTX_SPIN)
#define AML_WDT_LOCK_DESTROY(sc) mtx_destroy(&(sc)->mtx);
#define AML_WDT_CTRL_REG 0
#define AML_WDT_CTRL_CPU_WDRESET_MASK aml8726_wdt_soc_params.ctrl_cpu_mask
#define AML_WDT_CTRL_CPU_WDRESET_SHIFT 24
#define AML_WDT_CTRL_IRQ_EN (1 << 23)
#define AML_WDT_CTRL_EN aml8726_wdt_soc_params.ctrl_en
#define AML_WDT_CTRL_TERMINAL_CNT_MASK aml8726_wdt_soc_params.term_cnt_mask
#define AML_WDT_CTRL_TERMINAL_CNT_SHIFT 0
#define AML_WDT_RESET_REG 4
#define AML_WDT_RESET_CNT_MASK aml8726_wdt_soc_params.reset_cnt_mask
#define AML_WDT_RESET_CNT_SHIFT 0
#define CSR_WRITE_4(sc, reg, val) bus_write_4((sc)->res[0], reg, (val))
#define CSR_READ_4(sc, reg) bus_read_4((sc)->res[0], reg)
#define CSR_BARRIER(sc, reg) bus_barrier((sc)->res[0], reg, 4, \
(BUS_SPACE_BARRIER_READ | BUS_SPACE_BARRIER_WRITE))
static void
aml8726_wdt_watchdog(void *private, u_int cmd, int *error)
{
struct aml8726_wdt_softc *sc = (struct aml8726_wdt_softc *)private;
uint32_t wcr;
uint64_t tens_of_usec;
AML_WDT_LOCK(sc);
tens_of_usec = (((uint64_t)1 << (cmd & WD_INTERVAL)) + 9999) / 10000;
if (cmd != 0 && tens_of_usec <= (AML_WDT_CTRL_TERMINAL_CNT_MASK >>
AML_WDT_CTRL_TERMINAL_CNT_SHIFT)) {
wcr = AML_WDT_CTRL_CPU_WDRESET_MASK |
AML_WDT_CTRL_EN | ((uint32_t)tens_of_usec <<
AML_WDT_CTRL_TERMINAL_CNT_SHIFT);
CSR_WRITE_4(sc, AML_WDT_RESET_REG, 0);
CSR_WRITE_4(sc, AML_WDT_CTRL_REG, wcr);
*error = 0;
} else
CSR_WRITE_4(sc, AML_WDT_CTRL_REG,
(CSR_READ_4(sc, AML_WDT_CTRL_REG) &
~(AML_WDT_CTRL_IRQ_EN | AML_WDT_CTRL_EN)));
AML_WDT_UNLOCK(sc);
}
static int
aml8726_wdt_intr(void *arg)
{
struct aml8726_wdt_softc *sc = (struct aml8726_wdt_softc *)arg;
/*
* Normally a timeout causes a hardware reset, however
* the watchdog timer can be configured to cause an
* interrupt instead by setting AML_WDT_CTRL_IRQ_EN
* and clearing AML_WDT_CTRL_CPU_WDRESET_MASK.
*/
AML_WDT_LOCK(sc);
CSR_WRITE_4(sc, AML_WDT_CTRL_REG,
(CSR_READ_4(sc, AML_WDT_CTRL_REG) & ~(AML_WDT_CTRL_IRQ_EN |
AML_WDT_CTRL_EN)));
CSR_BARRIER(sc, AML_WDT_CTRL_REG);
AML_WDT_UNLOCK(sc);
device_printf(sc->dev, "timeout expired\n");
return (FILTER_HANDLED);
}
static int
aml8726_wdt_probe(device_t dev)
{
if (!ofw_bus_status_okay(dev))
return (ENXIO);
if (!ofw_bus_is_compatible(dev, "amlogic,meson6-wdt"))
return (ENXIO);
device_set_desc(dev, "Amlogic aml8726 WDT");
return (BUS_PROBE_DEFAULT);
}
static int
aml8726_wdt_attach(device_t dev)
{
struct aml8726_wdt_softc *sc = device_get_softc(dev);
/* There should be exactly one instance. */
if (aml8726_wdt_sc != NULL)
return (ENXIO);
sc->dev = dev;
if (bus_alloc_resources(dev, aml8726_wdt_spec, sc->res)) {
device_printf(dev, "can not allocate resources for device\n");
return (ENXIO);
}
/*
* Certain bitfields are dependent on the hardware revision.
*/
switch (aml8726_soc_hw_rev) {
case AML_SOC_HW_REV_M8:
aml8726_wdt_soc_params.ctrl_cpu_mask = 0xf <<
AML_WDT_CTRL_CPU_WDRESET_SHIFT;
switch (aml8726_soc_metal_rev) {
case AML_SOC_M8_METAL_REV_M2_A:
aml8726_wdt_soc_params.ctrl_en = 1 << 19;
aml8726_wdt_soc_params.term_cnt_mask = 0x07ffff <<
AML_WDT_CTRL_TERMINAL_CNT_SHIFT;
aml8726_wdt_soc_params.reset_cnt_mask = 0x07ffff <<
AML_WDT_RESET_CNT_SHIFT;
break;
default:
aml8726_wdt_soc_params.ctrl_en = 1 << 22;
aml8726_wdt_soc_params.term_cnt_mask = 0x3fffff <<
AML_WDT_CTRL_TERMINAL_CNT_SHIFT;
aml8726_wdt_soc_params.reset_cnt_mask = 0x3fffff <<
AML_WDT_RESET_CNT_SHIFT;
break;
}
break;
case AML_SOC_HW_REV_M8B:
aml8726_wdt_soc_params.ctrl_cpu_mask = 0xf <<
AML_WDT_CTRL_CPU_WDRESET_SHIFT;
aml8726_wdt_soc_params.ctrl_en = 1 << 19;
aml8726_wdt_soc_params.term_cnt_mask = 0x07ffff <<
AML_WDT_CTRL_TERMINAL_CNT_SHIFT;
aml8726_wdt_soc_params.reset_cnt_mask = 0x07ffff <<
AML_WDT_RESET_CNT_SHIFT;
break;
default:
aml8726_wdt_soc_params.ctrl_cpu_mask = 3 <<
AML_WDT_CTRL_CPU_WDRESET_SHIFT;
aml8726_wdt_soc_params.ctrl_en = 1 << 22;
aml8726_wdt_soc_params.term_cnt_mask = 0x3fffff <<
AML_WDT_CTRL_TERMINAL_CNT_SHIFT;
aml8726_wdt_soc_params.reset_cnt_mask = 0x3fffff <<
AML_WDT_RESET_CNT_SHIFT;
break;
}
/*
* Disable the watchdog.
*/
CSR_WRITE_4(sc, AML_WDT_CTRL_REG,
(CSR_READ_4(sc, AML_WDT_CTRL_REG) & ~(AML_WDT_CTRL_IRQ_EN |
AML_WDT_CTRL_EN)));
/*
* Initialize the mutex prior to installing the interrupt handler
* in case of a spurious interrupt.
*/
AML_WDT_LOCK_INIT(sc);
if (bus_setup_intr(dev, sc->res[1], INTR_TYPE_MISC | INTR_MPSAFE,
aml8726_wdt_intr, NULL, sc, &sc->ih_cookie)) {
device_printf(dev, "could not setup interrupt handler\n");
bus_release_resources(dev, aml8726_wdt_spec, sc->res);
AML_WDT_LOCK_DESTROY(sc);
return (ENXIO);
}
aml8726_wdt_sc = sc;
EVENTHANDLER_REGISTER(watchdog_list, aml8726_wdt_watchdog, sc, 0);
return (0);
}
static int
aml8726_wdt_detach(device_t dev)
{
return (EBUSY);
}
static device_method_t aml8726_wdt_methods[] = {
/* Device interface */
DEVMETHOD(device_probe, aml8726_wdt_probe),
DEVMETHOD(device_attach, aml8726_wdt_attach),
DEVMETHOD(device_detach, aml8726_wdt_detach),
DEVMETHOD_END
};
static driver_t aml8726_wdt_driver = {
"wdt",
aml8726_wdt_methods,
sizeof(struct aml8726_wdt_softc),
};
static devclass_t aml8726_wdt_devclass;
EARLY_DRIVER_MODULE(wdt, simplebus, aml8726_wdt_driver, aml8726_wdt_devclass,
0, 0, BUS_PASS_INTERRUPT + BUS_PASS_ORDER_LATE);
void
cpu_reset(void)
{
/* Watchdog has not yet been initialized */
if (aml8726_wdt_sc == NULL)
printf("Reset hardware has not yet been initialized.\n");
else {
CSR_WRITE_4(aml8726_wdt_sc, AML_WDT_RESET_REG, 0);
CSR_WRITE_4(aml8726_wdt_sc, AML_WDT_CTRL_REG,
(AML_WDT_CTRL_CPU_WDRESET_MASK | AML_WDT_CTRL_EN |
(10 << AML_WDT_CTRL_TERMINAL_CNT_SHIFT)));
}
while (1);
}