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/* $NetBSD: gpiopwm.c,v 1.7 2017/10/28 04:53:56 riastradh Exp $ */
/*
* Copyright (c) 2011 Marc Balmer <marc@msys.ch>
* 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 ``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 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.
*/
/*
* Driver for pulsing GPIO pins in software
*/
#include <sys/param.h>
#include <sys/device.h>
#include <sys/gpio.h>
#include <sys/sysctl.h>
#include <dev/gpio/gpiovar.h>
#include "ioconf.h"
#define GPIOPWM_NPINS 1
struct gpiopwm_softc {
device_t sc_dev;
void *sc_gpio;
struct gpio_pinmap sc_map;
int _map[GPIOPWM_NPINS];
callout_t sc_pulse;
int sc_ticks_on;
int sc_ticks_off;
struct sysctllog *sc_log;
int sc_dying;
};
int gpiopwm_match(device_t, cfdata_t, void *);
void gpiopwm_attach(device_t, device_t, void *);
int gpiopwm_detach(device_t, int);
int gpiopwm_activate(device_t, enum devact);
static int gpiopwm_set_on(SYSCTLFN_ARGS);
static int gpiopwm_set_off(SYSCTLFN_ARGS);
static void gpiopwm_pulse(void *);
CFATTACH_DECL_NEW(gpiopwm, sizeof(struct gpiopwm_softc),
gpiopwm_match, gpiopwm_attach, gpiopwm_detach, gpiopwm_activate);
int
gpiopwm_match(device_t parent, cfdata_t cf,
void *aux)
{
struct gpio_attach_args *ga = aux;
if (strcmp(ga->ga_dvname, cf->cf_name))
return 0;
if (ga->ga_offset == -1)
return 0;
/* Check number of pins, must be 1 */
if (gpio_npins(ga->ga_mask) != GPIOPWM_NPINS) {
aprint_debug("%s: invalid pin mask 0x%02x\n", cf->cf_name,
ga->ga_mask);
return 0;
}
return 1;
}
void
gpiopwm_attach(device_t parent, device_t self, void *aux)
{
struct gpiopwm_softc *sc = device_private(self);
struct gpio_attach_args *ga = aux;
const struct sysctlnode *node;
sc->sc_dev = self;
/* Map pin */
sc->sc_gpio = ga->ga_gpio;
sc->sc_map.pm_map = sc->_map;
if (gpio_pin_map(sc->sc_gpio, ga->ga_offset, ga->ga_mask,
&sc->sc_map)) {
aprint_error(": can't map pin\n");
return;
}
aprint_normal(" [%d]", sc->sc_map.pm_map[0]);
if (!pmf_device_register(self, NULL, NULL))
aprint_error_dev(self, "couldn't establish power handler\n");
callout_init(&sc->sc_pulse, CALLOUT_MPSAFE);
callout_setfunc(&sc->sc_pulse, gpiopwm_pulse, sc);
sysctl_createv(&sc->sc_log, 0, NULL, &node,
0,
CTLTYPE_NODE, device_xname(sc->sc_dev),
SYSCTL_DESCR("GPIO software PWM"),
NULL, 0, NULL, 0,
CTL_HW, CTL_CREATE, CTL_EOL);
if (node == NULL) {
aprint_error(": can't create sysctl node\n");
return;
}
sysctl_createv(&sc->sc_log, 0, &node, NULL,
CTLFLAG_READWRITE,
CTLTYPE_INT, "on",
SYSCTL_DESCR("PWM 'on' period in ticks"),
gpiopwm_set_on, 0, (void *)sc, 0,
CTL_CREATE, CTL_EOL);
sysctl_createv(&sc->sc_log, 0, &node, NULL,
CTLFLAG_READWRITE,
CTLTYPE_INT, "off",
SYSCTL_DESCR("PWM 'off' period in ticks"),
gpiopwm_set_off, 0, (void *)sc, 0,
CTL_CREATE, CTL_EOL);
aprint_normal("\n");
return;
}
int
gpiopwm_detach(device_t self, int flags)
{
struct gpiopwm_softc *sc = device_private(self);
callout_halt(&sc->sc_pulse, NULL);
callout_destroy(&sc->sc_pulse);
gpio_pin_write(sc->sc_gpio, &sc->sc_map, 0, GPIO_PIN_LOW);
pmf_device_deregister(self);
gpio_pin_unmap(sc->sc_gpio, &sc->sc_map);
if (sc->sc_log != NULL) {
sysctl_teardown(&sc->sc_log);
sc->sc_log = NULL;
}
return 0;
}
static int
gpiopwm_set_on(SYSCTLFN_ARGS)
{
struct sysctlnode node;
struct gpiopwm_softc *sc;
int val, error;
node = *rnode;
sc = node.sysctl_data;
callout_halt(&sc->sc_pulse, NULL);
gpio_pin_write(sc->sc_gpio, &sc->sc_map, 0, GPIO_PIN_LOW);
node.sysctl_data = &val;
val = sc->sc_ticks_on;
error = sysctl_lookup(SYSCTLFN_CALL(&node));
if (error || newp == NULL)
return error;
sc->sc_ticks_on = val;
if (sc->sc_ticks_on > 0 && sc->sc_ticks_off > 0) {
gpio_pin_write(sc->sc_gpio, &sc->sc_map, 0, GPIO_PIN_HIGH);
callout_schedule(&sc->sc_pulse, sc->sc_ticks_on);
}
return 0;
}
static int
gpiopwm_set_off(SYSCTLFN_ARGS)
{
struct sysctlnode node;
struct gpiopwm_softc *sc;
int val, error;
node = *rnode;
sc = node.sysctl_data;
callout_halt(&sc->sc_pulse, NULL);
gpio_pin_write(sc->sc_gpio, &sc->sc_map, 0, GPIO_PIN_LOW);
node.sysctl_data = &val;
val = sc->sc_ticks_off;
error = sysctl_lookup(SYSCTLFN_CALL(&node));
if (error || newp == NULL)
return error;
sc->sc_ticks_off = val;
if (sc->sc_ticks_on > 0 && sc->sc_ticks_off > 0) {
gpio_pin_write(sc->sc_gpio, &sc->sc_map, 0, GPIO_PIN_HIGH);
callout_schedule(&sc->sc_pulse, sc->sc_ticks_on);
}
return 0;
}
static void
gpiopwm_pulse(void *arg)
{
struct gpiopwm_softc *sc;
sc = arg;
if (gpio_pin_read(sc->sc_gpio, &sc->sc_map, 0) == GPIO_PIN_HIGH) {
gpio_pin_write(sc->sc_gpio, &sc->sc_map, 0, GPIO_PIN_LOW);
callout_schedule(&sc->sc_pulse, sc->sc_ticks_off);
} else {
gpio_pin_write(sc->sc_gpio, &sc->sc_map, 0, GPIO_PIN_HIGH);
callout_schedule(&sc->sc_pulse, sc->sc_ticks_on);
}
}
int
gpiopwm_activate(device_t self, enum devact act)
{
struct gpiopwm_softc *sc = device_private(self);
switch (act) {
case DVACT_DEACTIVATE:
sc->sc_dying = 1;
return 0;
default:
return EOPNOTSUPP;
}
}
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