freebsd-dev/sys/arm/ti/am335x/am335x_ecap.c

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/*-
* Copyright (c) 2013 Oleksandr Tymoshenko <gonzo@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/limits.h>
#include <sys/lock.h>
#include <sys/module.h>
#include <sys/mutex.h>
#include <sys/resource.h>
#include <sys/rman.h>
#include <sys/sysctl.h>
#include <machine/bus.h>
#include <dev/ofw/openfirm.h>
#include <dev/ofw/ofw_bus.h>
#include <dev/ofw/ofw_bus_subr.h>
#include "am335x_pwm.h"
#define ECAP_TSCTR 0x00
#define ECAP_CAP1 0x08
#define ECAP_CAP2 0x0C
#define ECAP_CAP3 0x10
#define ECAP_CAP4 0x14
#define ECAP_ECCTL2 0x2A
#define ECCTL2_MODE_APWM (1 << 9)
#define ECCTL2_SYNCO_SEL (3 << 6)
#define ECCTL2_TSCTRSTOP_FREERUN (1 << 4)
#define ECAP_READ2(_sc, reg) bus_read_2((_sc)->sc_mem_res, reg);
#define ECAP_WRITE2(_sc, reg, value) \
bus_write_2((_sc)->sc_mem_res, reg, value);
#define ECAP_READ4(_sc, reg) bus_read_4((_sc)->sc_mem_res, reg);
#define ECAP_WRITE4(_sc, reg, value) \
bus_write_4((_sc)->sc_mem_res, reg, value);
#define PWM_LOCK(_sc) mtx_lock(&(_sc)->sc_mtx)
#define PWM_UNLOCK(_sc) mtx_unlock(&(_sc)->sc_mtx)
#define PWM_LOCK_INIT(_sc) mtx_init(&(_sc)->sc_mtx, \
device_get_nameunit(_sc->sc_dev), "am335x_ecap softc", MTX_DEF)
#define PWM_LOCK_DESTROY(_sc) mtx_destroy(&(_sc)->sc_mtx)
static device_probe_t am335x_ecap_probe;
static device_attach_t am335x_ecap_attach;
static device_detach_t am335x_ecap_detach;
struct am335x_ecap_softc {
device_t sc_dev;
struct mtx sc_mtx;
struct resource *sc_mem_res;
int sc_mem_rid;
};
static device_method_t am335x_ecap_methods[] = {
DEVMETHOD(device_probe, am335x_ecap_probe),
DEVMETHOD(device_attach, am335x_ecap_attach),
DEVMETHOD(device_detach, am335x_ecap_detach),
DEVMETHOD_END
};
static driver_t am335x_ecap_driver = {
"am335x_ecap",
am335x_ecap_methods,
sizeof(struct am335x_ecap_softc),
};
static devclass_t am335x_ecap_devclass;
/*
* API function to set period/duty cycles for ECAPx
*/
int
am335x_pwm_config_ecap(int unit, int period, int duty)
{
device_t dev;
struct am335x_ecap_softc *sc;
uint16_t reg;
dev = devclass_get_device(am335x_ecap_devclass, unit);
if (dev == NULL)
return (ENXIO);
if (duty > period)
return (EINVAL);
if (period == 0)
return (EINVAL);
sc = device_get_softc(dev);
PWM_LOCK(sc);
reg = ECAP_READ2(sc, ECAP_ECCTL2);
reg |= ECCTL2_MODE_APWM | ECCTL2_TSCTRSTOP_FREERUN | ECCTL2_SYNCO_SEL;
ECAP_WRITE2(sc, ECAP_ECCTL2, reg);
/* CAP3 in APWM mode is APRD shadow register */
ECAP_WRITE4(sc, ECAP_CAP3, period - 1);
/* CAP4 in APWM mode is ACMP shadow register */
ECAP_WRITE4(sc, ECAP_CAP4, duty);
/* Restart counter */
ECAP_WRITE4(sc, ECAP_TSCTR, 0);
PWM_UNLOCK(sc);
return (0);
}
static int
am335x_ecap_probe(device_t dev)
{
if (!ofw_bus_status_okay(dev))
return (ENXIO);
if (!ofw_bus_is_compatible(dev, "ti,am33xx-ecap"))
return (ENXIO);
device_set_desc(dev, "AM335x eCAP");
return (BUS_PROBE_DEFAULT);
}
static int
am335x_ecap_attach(device_t dev)
{
struct am335x_ecap_softc *sc;
sc = device_get_softc(dev);
sc->sc_dev = dev;
PWM_LOCK_INIT(sc);
sc->sc_mem_res = bus_alloc_resource_any(dev, SYS_RES_MEMORY,
&sc->sc_mem_rid, RF_ACTIVE);
if (sc->sc_mem_res == NULL) {
device_printf(dev, "cannot allocate memory resources\n");
goto fail;
}
return (0);
fail:
PWM_LOCK_DESTROY(sc);
return (ENXIO);
}
static int
am335x_ecap_detach(device_t dev)
{
struct am335x_ecap_softc *sc;
sc = device_get_softc(dev);
PWM_LOCK(sc);
if (sc->sc_mem_res)
bus_release_resource(dev, SYS_RES_MEMORY,
sc->sc_mem_rid, sc->sc_mem_res);
PWM_UNLOCK(sc);
PWM_LOCK_DESTROY(sc);
return (0);
}
DRIVER_MODULE(am335x_ecap, am335x_pwmss, am335x_ecap_driver, am335x_ecap_devclass, 0, 0);
MODULE_VERSION(am335x_ecap, 1);
MODULE_DEPEND(am335x_ecap, am335x_pwmss, 1, 1, 1);