/* $NetBSD: gpiokeys.c,v 1.11 2021/08/07 16:19:10 thorpej Exp $ */

/*-
 * Copyright (c) 2015 Jared D. McNeill <jmcneill@invisible.ca>
 * 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 <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: gpiokeys.c,v 1.11 2021/08/07 16:19:10 thorpej Exp $");

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

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

#include <dev/wscons/wsconsio.h>
#include <dev/wscons/wskbdvar.h>
#include <dev/wscons/wsksymdef.h>
#include <dev/wscons/wsksymvar.h>
#include <dev/wscons/linux_keymap.h>

#include <dev/fdt/fdtvar.h>

#define GPIOKEYS_POLL_INTERVAL  mstohz(200)

/* Event types */
#define EV_KEY          1
#define EV_SW           5

/* Key and button events */
#define KEY_POWER       116
#define KEY_SLEEP       142

/* Switch events */
#define SW_LID          0

static int      gpiokeys_match(device_t, cfdata_t, void *);
static void     gpiokeys_attach(device_t, device_t, void *);

static void     gpiokeys_tick(void *);
static void     gpiokeys_task(void *);

extern const struct wscons_keydesc hidkbd_keydesctab[];
static const struct wskbd_mapdata gpiokeys_keymapdata = {
        hidkbd_keydesctab,
        KB_US,
};

struct gpiokeys_softc;

struct gpiokeys_key {
        struct gpiokeys_softc   *key_sc;
        int                     key_phandle;
        char                    *key_label;
        struct fdtbus_gpio_pin  *key_pin;
        u_int                   key_debounce;
        u_int                   key_code;
        struct sysmon_pswitch   key_pswitch;
        uint8_t                 key_usbcode;
        int                     key_state;

        struct gpiokeys_key     *key_next;
};

struct gpiokeys_softc {
        device_t        sc_dev;
        int             sc_phandle;

        struct fdtbus_gpio_pin *sc_pin;
        bool            sc_always_on;
        bool            sc_enable_val;

        struct gpiokeys_key *sc_keys;
        callout_t       sc_tick;

        device_t        sc_wskbddev;
        int             sc_enabled;
};

CFATTACH_DECL_NEW(gpiokeys, sizeof(struct gpiokeys_softc),
    gpiokeys_match, gpiokeys_attach, NULL, NULL);

static int
gpiokeys_enable(void *v, int on)
{
        struct gpiokeys_softc * const sc = v;

        sc->sc_enabled = on;

        return 0;
}

static void
gpiokeys_set_leds(void *v, int leds)
{
}

static int
gpiokeys_ioctl(void *v, u_long cmd, void *data, int flag, lwp_t *l)
{
        switch (cmd) {
        case WSKBDIO_GTYPE:
                *(int *)data = WSKBD_TYPE_USB;
                return 0;
        }

        return EPASSTHROUGH;
}

static const struct wskbd_accessops gpiokeys_accessops = {
        .enable = gpiokeys_enable,
        .set_leds = gpiokeys_set_leds,
        .ioctl = gpiokeys_ioctl
};

static const struct device_compatible_entry compat_data[] = {
        { .compat = "gpio-keys" },
        DEVICE_COMPAT_EOL
};

static int
gpiokeys_match(device_t parent, cfdata_t cf, void *aux)
{
        const struct fdt_attach_args *faa = aux;

        return of_compatible_match(faa->faa_phandle, compat_data);
}

static void
gpiokeys_attach(device_t parent, device_t self, void *aux)
{
        struct gpiokeys_softc * const sc = device_private(self);
        const struct fdt_attach_args *faa = aux;
        const int phandle = faa->faa_phandle;
        struct gpiokeys_key *key;
        u_int debounce, input_type, code;
        int use_wskbddev = 0;
        int child, len;

        sc->sc_dev = self;
        sc->sc_phandle = phandle;

        aprint_naive("\n");
        aprint_normal(":");

        for (child = OF_child(phandle); child; child = OF_peer(child)) {
                if (of_getprop_uint32(child, "linux,input-type", &input_type))
                        input_type = EV_KEY;    /* default */
                if (of_getprop_uint32(child, "linux,code", &code))
                        continue;
                if (of_getprop_uint32(child, "debounce-interval", &debounce))
                        debounce = 5;   /* default */
                len = OF_getproplen(child, "label");
                if (len <= 0) {
                        continue;
                }
                key = kmem_zalloc(sizeof(*key), KM_SLEEP);
                key->key_sc = sc;
                key->key_phandle = child;
                key->key_code = code;
                key->key_label = kmem_zalloc(len, KM_SLEEP);
                if (OF_getprop(child, "label", key->key_label, len) != len) {
                        kmem_free(key->key_label, len);
                        kmem_free(key, sizeof(*key));
                        continue;
                }
                key->key_debounce = debounce;
                key->key_pin = fdtbus_gpio_acquire(child, "gpios",
                    GPIO_PIN_INPUT);
                if (key->key_pin)
                        key->key_state = fdtbus_gpio_read(key->key_pin);

                switch (input_type) {
                case EV_KEY:
                        switch (code) {
                        case KEY_POWER:
                                key->key_pswitch.smpsw_name = key->key_label;
                                key->key_pswitch.smpsw_type = PSWITCH_TYPE_POWER;
                                break;
                        case KEY_SLEEP:
                                key->key_pswitch.smpsw_name = key->key_label;
                                key->key_pswitch.smpsw_type = PSWITCH_TYPE_SLEEP;
                                break;
                        default:
                                key->key_usbcode = linux_key_to_usb(code);
                                if (key->key_usbcode != 0) {
                                        use_wskbddev++;
                                } else {
                                        key->key_pswitch.smpsw_name = key->key_label;
                                        key->key_pswitch.smpsw_type = PSWITCH_TYPE_HOTKEY;
                                }
                                break;
                        }
                        break;
                case EV_SW:
                        key->key_pswitch.smpsw_name = key->key_label;
                        switch (code) {
                        case SW_LID:
                                key->key_state = -1;    /* Send notification on attach */
                                key->key_pswitch.smpsw_type = PSWITCH_TYPE_LID;
                                break;
                        default:
                                key->key_pswitch.smpsw_type = PSWITCH_TYPE_HOTKEY;
                                break;
                        }
                        break;
                }

                if (key->key_pswitch.smpsw_name != NULL &&
                    sysmon_pswitch_register(&key->key_pswitch) != 0) {
                        aprint_error(" %s:ERROR", key->key_label);
                        kmem_free(key->key_label, len);
                        kmem_free(key, sizeof(*key));
                        continue;
                }

                if (sc->sc_keys) {
                        aprint_normal(", %s", key->key_label);
                } else {
                        aprint_normal(" %s", key->key_label);
                }

                key->key_next = sc->sc_keys;
                sc->sc_keys = key;
        }

        if (sc->sc_keys == NULL) {
                aprint_normal(" no keys configured\n");
                return;
        }

        aprint_normal("\n");

        if (use_wskbddev > 0) {
                struct wskbddev_attach_args a;
                memset(&a, 0, sizeof(a));
                a.console = false;
                a.keymap = &gpiokeys_keymapdata;
                a.accessops = &gpiokeys_accessops;
                a.accesscookie = sc;
                sc->sc_wskbddev =
                    config_found(self, &a, wskbddevprint, CFARGS_NONE);
        }

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

        gpiokeys_tick(sc);
}

static void
gpiokeys_tick(void *priv)
{
        struct gpiokeys_softc * const sc = priv;
        struct gpiokeys_key *key;

        for (key = sc->sc_keys; key; key = key->key_next) {
                if (key->key_pin == NULL) {
                        continue;
                }
                const int new_state = fdtbus_gpio_read(key->key_pin);
                if (new_state != key->key_state) {
                        key->key_state = new_state;
                        sysmon_task_queue_sched(0, gpiokeys_task, key);
                }
        }
        callout_schedule(&sc->sc_tick, GPIOKEYS_POLL_INTERVAL);
}

static void
gpiokeys_task(void *priv)
{
        struct gpiokeys_key *key = priv;
        struct gpiokeys_softc *sc = key->key_sc;

        if (key->key_pswitch.smpsw_name) {
                sysmon_pswitch_event(&key->key_pswitch,
                    key->key_state ? PSWITCH_EVENT_PRESSED : PSWITCH_EVENT_RELEASED);
        } else if (sc->sc_enabled && sc->sc_wskbddev != NULL && key->key_usbcode != 0) {
                wskbd_input(sc->sc_wskbddev,
                    key->key_state ? WSCONS_EVENT_KEY_DOWN : WSCONS_EVENT_KEY_UP,
                    key->key_usbcode);
        }
}