/* $NetBSD: gpiobutton.c,v 1.3 2015/10/04 18:35:44 jmcneill Exp $ */

/* $NetBSD: gpiobutton.c,v 1.3 2015/10/04 18:35:44 jmcneill Exp $ */

/*-
* Copyright (c) 2015 Jared D. McNeill <[email protected]>
* 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.
*/

#include "locators.h"

#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: gpiobutton.c,v 1.3 2015/10/04 18:35:44 jmcneill Exp $");

#include <sys/param.h>
#include <sys/bus.h>
#include <sys/device.h>
#include <sys/intr.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/gpio.h>

#include <dev/sysmon/sysmonvar.h>
#include <dev/sysmon/sysmon_taskq.h>

#include <dev/gpio/gpiovar.h>

#define GPIOBUTTON_POLL_INTERVAL mstohz(200)

#define GPIOBUTTON_POLARITY_MASK 0x80
#define GPIOBUTTON_POLARITY_ACTIVE_LOW 0
#define GPIOBUTTON_POLARITY_ACTIVE_HIGH 1
#define GPIOBUTTON_TYPE_MASK 0x0f
#define GPIOBUTTON_TYPE_POWER 1
#define GPIOBUTTON_TYPE_SLEEP 2

static int gpiobutton_match(device_t, cfdata_t, void *);
static void gpiobutton_attach(device_t, device_t, void *);

struct gpiobutton_softc {
device_t sc_dev;
void *sc_gpio;
struct gpio_pinmap sc_map;
int sc_pinmap[1];
bool sc_active_high;

struct sysmon_pswitch sc_smpsw;

callout_t sc_tick;
bool sc_state;
};

static bool gpiobutton_is_pressed(struct gpiobutton_softc *);
static void gpiobutton_tick(void *);
static void gpiobutton_task(void *);

CFATTACH_DECL_NEW(gpiobutton, sizeof(struct gpiobutton_softc),
gpiobutton_match, gpiobutton_attach, NULL, NULL);

static int
gpiobutton_match(device_t parent, cfdata_t cf, void *aux)
{
struct gpio_attach_args * const ga = aux;

if (strcmp(ga->ga_dvname, cf->cf_name) != 0)
return 0;

if (ga->ga_offset == -1 || gpio_npins(ga->ga_mask) != 1)
return 0;

const u_int type = __SHIFTOUT(ga->ga_flags, GPIOBUTTON_TYPE_MASK);

switch (type) {
case GPIOBUTTON_TYPE_POWER:
case GPIOBUTTON_TYPE_SLEEP:
return 1;
default:
return 0;
}
}

static void
gpiobutton_attach(device_t parent, device_t self, void *aux)
{
struct gpiobutton_softc * const sc = device_private(self);
struct gpio_attach_args * const ga = aux;
const char *desc;
int caps;

const u_int type = __SHIFTOUT(ga->ga_flags, GPIOBUTTON_TYPE_MASK);
const u_int pol = __SHIFTOUT(ga->ga_flags, GPIOBUTTON_POLARITY_MASK);

sc->sc_dev = self;
sc->sc_gpio = ga->ga_gpio;
sc->sc_map.pm_map = sc->sc_pinmap;
if (gpio_pin_map(sc->sc_gpio, ga->ga_offset, ga->ga_mask,
&sc->sc_map)) {
aprint_error(": couldn't map pins\n");
return;
}
sc->sc_active_high = pol == GPIOBUTTON_POLARITY_ACTIVE_HIGH;

caps = gpio_pin_caps(sc->sc_gpio, &sc->sc_map, 0);
if ((caps & GPIO_PIN_INPUT) == 0) {
aprint_error(": pin is not an input pin\n");
return;
}

gpio_pin_ctl(sc->sc_gpio, &sc->sc_map, 0, GPIO_PIN_INPUT);

sc->sc_smpsw.smpsw_name = device_xname(self);
switch (type) {
case GPIOBUTTON_TYPE_POWER:
sc->sc_smpsw.smpsw_type = PSWITCH_TYPE_POWER;
desc = "Power";
break;
case GPIOBUTTON_TYPE_SLEEP:
sc->sc_smpsw.smpsw_type = PSWITCH_TYPE_SLEEP;
desc = "Sleep";
break;
default:
panic("%s: impossible", __func__);
}

aprint_naive("\n");
aprint_normal(": %s button\n", desc);

sysmon_pswitch_register(&sc->sc_smpsw);

callout_init(&sc->sc_tick, CALLOUT_MPSAFE);
callout_setfunc(&sc->sc_tick, gpiobutton_tick, sc);

gpiobutton_tick(sc);
}

static bool
gpiobutton_is_pressed(struct gpiobutton_softc *sc)
{
int val;

val = gpio_pin_read(sc->sc_gpio, &sc->sc_map, 0);
if (!sc->sc_active_high)
val = !val;

return val;
}

static void
gpiobutton_tick(void *priv)
{
struct gpiobutton_softc * const sc = priv;

const bool new_state = gpiobutton_is_pressed(sc);
if (new_state != sc->sc_state) {
sc->sc_state = new_state;
sysmon_task_queue_sched(0, gpiobutton_task, sc);
}
callout_schedule(&sc->sc_tick, GPIOBUTTON_POLL_INTERVAL);
}

static void
gpiobutton_task(void *priv)
{
struct gpiobutton_softc * const sc = priv;

sysmon_pswitch_event(&sc->sc_smpsw,
sc->sc_state ? PSWITCH_EVENT_PRESSED : PSWITCH_EVENT_RELEASED);
}