/*	$OpenBSD: gpiokeys.c,v 1.1 2021/11/09 16:16:11 kn Exp $	*/
/*
 * Copyright (c) 2021 Klemens Nanni <kn@openbsd.org>
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/device.h>
#include <sys/gpio.h>
#include <sys/malloc.h>
#include <sys/queue.h>

#include <machine/bus.h>
#include <machine/fdt.h>

#include <dev/gpio/gpiovar.h>
#include <dev/ofw/ofw_gpio.h>
#include <dev/ofw/ofw_pinctrl.h>
#include <dev/ofw/openfirm.h>
#include <dev/ofw/fdt.h>

#include <sys/sensors.h>

#define	DEVNAME(_s)	((_s)->sc_dev.dv_xname)

/*
 * Defines from Linux, see:
 *	Documentation/input/event-codes.rst
 *	include/dt-bindings/input/linux-event-codes.h
 */
enum gpiokeys_event_type {
	GPIOKEYS_EV_KEY = 1,
	GPIOKEYS_EV_SW = 5,
};

enum gpiokeys_switch_event {
	GPIOKEYS_SW_LID = 0,	/* set = lid closed */
};

struct gpiokeys_key {
	uint32_t			*key_pin;
	uint32_t			 key_input_type;
	uint32_t			 key_code;
	struct ksensor			 key_sensor;
	SLIST_ENTRY(gpiokeys_key)	 entries;
};

struct gpiokeys_softc {
	struct device			 sc_dev;
	int				 sc_node;
	struct ksensordev		 sc_sensordev;
	SLIST_HEAD(, gpiokeys_key)	 sc_keys;
};

int	 gpiokeys_match(struct device *, void *, void *);
void	 gpiokeys_attach(struct device *, struct device *, void *);

const struct cfattach gpiokeys_ca = {
	sizeof (struct gpiokeys_softc), gpiokeys_match, gpiokeys_attach
};

struct cfdriver gpiokeys_cd = {
	NULL, "gpiokeys", DV_DULL
};

void	 gpiokeys_update_key(void *);

int
gpiokeys_match(struct device *parent, void *match, void *aux)
{
	const struct fdt_attach_args	*faa = aux;

	return OF_is_compatible(faa->fa_node, "gpio-keys") ||
	    OF_is_compatible(faa->fa_node, "gpio-keys-polled");
}

void
gpiokeys_attach(struct device *parent, struct device *self, void *aux)
{
	struct gpiokeys_softc	*sc = (struct gpiokeys_softc *)self;
	struct fdt_attach_args	*faa = aux;
	struct gpiokeys_key	*key;
	char			*label;
	uint32_t		 code;
	int			 node, len, gpios_len, have_sensors = 0;

	SLIST_INIT(&sc->sc_keys);

	pinctrl_byname(faa->fa_node, "default");

	for (node = OF_child(faa->fa_node); node; node = OF_peer(node)) {
		if (OF_getprop(node, "linux,code", &code, sizeof(code)) == -1)
			continue;
		gpios_len = OF_getproplen(node, "gpios");
		if (gpios_len <= 0)
			continue;
		len = OF_getproplen(node, "label");
		if (len <= 0)
			continue;
		label = malloc(len, M_TEMP, M_WAITOK);
		if (OF_getprop(node, "label", label, len) != len) {
			free(label, M_TEMP, len);
			continue;
		}
		key = malloc(sizeof(*key), M_DEVBUF, M_WAITOK | M_ZERO);
		key->key_input_type = OF_getpropint(node, "linux,input-type",
		    GPIOKEYS_EV_KEY);
		key->key_code = code;
		key->key_pin = malloc(gpios_len, M_DEVBUF, M_WAITOK);
		OF_getpropintarray(node, "gpios", key->key_pin, gpios_len);
		gpio_controller_config_pin(key->key_pin, GPIO_CONFIG_INPUT);

		switch (key->key_input_type) {
		case GPIOKEYS_EV_SW:
			switch (key->key_code) {
			case GPIOKEYS_SW_LID:
				strlcpy(key->key_sensor.desc, "lid open",
				    sizeof(key->key_sensor.desc));
				key->key_sensor.type = SENSOR_INDICATOR;
				sensor_attach(&sc->sc_sensordev, &key->key_sensor);
				sensor_task_register(key, gpiokeys_update_key, 1);
				have_sensors = 1;
				break;
			}
			break;
		}

		printf("%s \"%s\"", SLIST_EMPTY(&sc->sc_keys) ? ":" : ",",
		    label);
		free(label, M_TEMP, len);

		SLIST_INSERT_HEAD(&sc->sc_keys, key, entries);
	}

	if (have_sensors) {
		strlcpy(sc->sc_sensordev.xname, DEVNAME(sc),
		    sizeof(sc->sc_sensordev.xname));
		sensordev_install(&sc->sc_sensordev);
	}

	if (SLIST_EMPTY(&sc->sc_keys))
		printf(": no keys");
	printf("\n");
}

void
gpiokeys_update_key(void *arg)
{
	struct gpiokeys_key	*key = arg;
	int			 val;

	val = gpio_controller_get_pin(key->key_pin);

	switch (key->key_input_type) {
	case GPIOKEYS_EV_SW:
		switch (key->key_code) {
		case GPIOKEYS_SW_LID:
			/*
			 * Match acpibtn(4), i.e. closed ThinkPad lid yields
			 * hw.sensors.acpibtn1.indicator0=Off (lid open)
			 */
			key->key_sensor.value = !val;
			break;
		}
		break;
	}
}