/*-
 * SPDX-License-Identifier: BSD-2-Clause
 *
 * Copyright (c) 2010 Hans Petter Selasky. 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.
 */

/*
 * HID spec: http://www.usb.org/developers/devclass_docs/HID1_11.pdf
 */

#include <sys/param.h>
#include <sys/stdint.h>
#include <sys/stddef.h>
#include <sys/queue.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/bus.h>
#include <sys/linker_set.h>
#include <sys/module.h>
#include <sys/lock.h>
#include <sys/mutex.h>
#include <sys/condvar.h>
#include <sys/sysctl.h>
#include <sys/sx.h>
#include <sys/unistd.h>
#include <sys/callout.h>
#include <sys/malloc.h>
#include <sys/priv.h>

#include <dev/usb/usb.h>
#include <dev/usb/usbdi.h>
#include <dev/usb/usbdi_util.h>
#include <dev/usb/usbhid.h>
#include "usb_if.h"

#define USB_DEBUG_VAR g_keyboard_debug
#include <dev/usb/usb_debug.h>

#include <dev/usb/gadget/g_keyboard.h>

static SYSCTL_NODE(_hw_usb, OID_AUTO, g_keyboard,
    CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
    "USB keyboard gadget");

#ifdef USB_DEBUG
static int g_keyboard_debug = 0;

SYSCTL_INT(_hw_usb_g_keyboard, OID_AUTO, debug, CTLFLAG_RWTUN,
    &g_keyboard_debug, 0, "Debug level");
#endif

static int g_keyboard_mode = 0;

SYSCTL_INT(_hw_usb_g_keyboard, OID_AUTO, mode, CTLFLAG_RWTUN,
    &g_keyboard_mode, 0, "Mode selection");

static int g_keyboard_key_press_interval = 1000;

SYSCTL_INT(_hw_usb_g_keyboard, OID_AUTO, key_press_interval, CTLFLAG_RWTUN,
    &g_keyboard_key_press_interval, 0, "Key Press Interval in milliseconds");

static char g_keyboard_key_press_pattern[G_KEYBOARD_MAX_STRLEN];

SYSCTL_STRING(_hw_usb_g_keyboard, OID_AUTO, key_press_pattern, CTLFLAG_RW,
    g_keyboard_key_press_pattern, sizeof(g_keyboard_key_press_pattern),
    "Key Press Patterns");

#define UPROTO_BOOT_KEYBOARD 1

#define G_KEYBOARD_NMOD                     8   /* units */
#define G_KEYBOARD_NKEYCODE                 6   /* units */

struct g_keyboard_data {
        uint8_t modifiers;
#define MOD_CONTROL_L   0x01
#define MOD_CONTROL_R   0x10
#define MOD_SHIFT_L     0x02
#define MOD_SHIFT_R     0x20
#define MOD_ALT_L       0x04
#define MOD_ALT_R       0x40
#define MOD_WIN_L       0x08
#define MOD_WIN_R       0x80
        uint8_t reserved;
        uint8_t keycode[G_KEYBOARD_NKEYCODE];
};

enum {
        G_KEYBOARD_INTR_DT,
        G_KEYBOARD_N_TRANSFER,
};

struct g_keyboard_softc {
        struct mtx sc_mtx;
        struct usb_callout sc_callout;
        struct g_keyboard_data sc_data[2];
        struct usb_xfer *sc_xfer[G_KEYBOARD_N_TRANSFER];

        int     sc_mode;
        int     sc_state;
        int     sc_pattern_len;

        char    sc_pattern[G_KEYBOARD_MAX_STRLEN];

        uint8_t sc_led_state[4];
};

static device_probe_t g_keyboard_probe;
static device_attach_t g_keyboard_attach;
static device_detach_t g_keyboard_detach;
static usb_handle_request_t g_keyboard_handle_request;
static usb_callback_t g_keyboard_intr_callback;

static device_method_t g_keyboard_methods[] = {
        /* USB interface */
        DEVMETHOD(usb_handle_request, g_keyboard_handle_request),

        /* Device interface */
        DEVMETHOD(device_probe, g_keyboard_probe),
        DEVMETHOD(device_attach, g_keyboard_attach),
        DEVMETHOD(device_detach, g_keyboard_detach),

        DEVMETHOD_END
};

static driver_t g_keyboard_driver = {
        .name = "g_keyboard",
        .methods = g_keyboard_methods,
        .size = sizeof(struct g_keyboard_softc),
};

DRIVER_MODULE(g_keyboard, uhub, g_keyboard_driver, 0, 0);
MODULE_DEPEND(g_keyboard, usb, 1, 1, 1);

static const struct usb_config g_keyboard_config[G_KEYBOARD_N_TRANSFER] = {
        [G_KEYBOARD_INTR_DT] = {
                .type = UE_INTERRUPT,
                .endpoint = UE_ADDR_ANY,
                .direction = UE_DIR_IN,
                .flags = {.ext_buffer = 1,.pipe_bof = 1,},
                .bufsize = sizeof(struct g_keyboard_data),
                .callback = &g_keyboard_intr_callback,
                .frames = 2,
                .usb_mode = USB_MODE_DEVICE,
        },
};

static void g_keyboard_timeout(void *arg);

static void
g_keyboard_timeout_reset(struct g_keyboard_softc *sc)
{
        int i = g_keyboard_key_press_interval;

        if (i <= 0)
                i = 1;
        else if (i > 1023)
                i = 1023;

        i = USB_MS_TO_TICKS(i);

        usb_callout_reset(&sc->sc_callout, i, &g_keyboard_timeout, sc);
}

static void
g_keyboard_timeout(void *arg)
{
        struct g_keyboard_softc *sc = arg;

        sc->sc_mode = g_keyboard_mode;

        memcpy(sc->sc_pattern, g_keyboard_key_press_pattern, sizeof(sc->sc_pattern));

        sc->sc_pattern[G_KEYBOARD_MAX_STRLEN - 1] = 0;

        sc->sc_pattern_len = strlen(sc->sc_pattern);

        DPRINTFN(11, "Timeout %p\n", sc->sc_xfer[G_KEYBOARD_INTR_DT]);

        usbd_transfer_start(sc->sc_xfer[G_KEYBOARD_INTR_DT]);

        g_keyboard_timeout_reset(sc);
}

static int
g_keyboard_probe(device_t dev)
{
        struct usb_attach_arg *uaa = device_get_ivars(dev);

        DPRINTFN(11, "\n");

        if (uaa->usb_mode != USB_MODE_DEVICE)
                return (ENXIO);

        if ((uaa->info.bInterfaceClass == UICLASS_HID) &&
            (uaa->info.bInterfaceSubClass == UISUBCLASS_BOOT) &&
            (uaa->info.bInterfaceProtocol == UPROTO_BOOT_KEYBOARD))
                return (0);

        return (ENXIO);
}

static int
g_keyboard_attach(device_t dev)
{
        struct g_keyboard_softc *sc = device_get_softc(dev);
        struct usb_attach_arg *uaa = device_get_ivars(dev);
        int error;

        DPRINTFN(11, "\n");

        device_set_usb_desc(dev);

        mtx_init(&sc->sc_mtx, "g_keyboard", NULL, MTX_DEF);

        usb_callout_init_mtx(&sc->sc_callout, &sc->sc_mtx, 0);

        sc->sc_mode = G_KEYBOARD_MODE_SILENT;

        error = usbd_transfer_setup(uaa->device,
            &uaa->info.bIfaceIndex, sc->sc_xfer, g_keyboard_config,
            G_KEYBOARD_N_TRANSFER, sc, &sc->sc_mtx);

        if (error) {
                DPRINTF("error=%s\n", usbd_errstr(error));
                goto detach;
        }
        mtx_lock(&sc->sc_mtx);
        g_keyboard_timeout_reset(sc);
        mtx_unlock(&sc->sc_mtx);

        return (0);                     /* success */

detach:
        g_keyboard_detach(dev);

        return (ENXIO);                 /* error */
}

static int
g_keyboard_detach(device_t dev)
{
        struct g_keyboard_softc *sc = device_get_softc(dev);

        DPRINTF("\n");

        mtx_lock(&sc->sc_mtx);
        usb_callout_stop(&sc->sc_callout);
        mtx_unlock(&sc->sc_mtx);

        usbd_transfer_unsetup(sc->sc_xfer, G_KEYBOARD_N_TRANSFER);

        usb_callout_drain(&sc->sc_callout);

        mtx_destroy(&sc->sc_mtx);

        return (0);
}

static uint8_t
g_keyboard_get_keycode(struct g_keyboard_softc *sc, int index)
{
        int key;
        int mod = sc->sc_pattern_len;

        if (mod == 0)
                index = 0;
        else
                index %= mod;

        if ((index >= 0) && (index < sc->sc_pattern_len))
                key = sc->sc_pattern[index];
        else
                key = 'a';

        if (key >= 'a' && key <= 'z')
                return (key - 'a' + 0x04);
        else
                return (0x04);
}

static void
g_keyboard_intr_callback(struct usb_xfer *xfer, usb_error_t error)
{
        struct g_keyboard_softc *sc = usbd_xfer_softc(xfer);
        int actlen;
        int aframes;

        usbd_xfer_status(xfer, &actlen, NULL, &aframes, NULL);

        DPRINTF("st=%d aframes=%d actlen=%d bytes\n",
            USB_GET_STATE(xfer), aframes, actlen);

        switch (USB_GET_STATE(xfer)) {
        case USB_ST_TRANSFERRED:
                break;

        case USB_ST_SETUP:
tr_setup:
                if (sc->sc_mode == G_KEYBOARD_MODE_SILENT) {
                        memset(&sc->sc_data, 0, sizeof(sc->sc_data));
                        usbd_xfer_set_frame_data(xfer, 0, &sc->sc_data[0], sizeof(sc->sc_data[0]));
                        usbd_xfer_set_frame_data(xfer, 1, &sc->sc_data[1], sizeof(sc->sc_data[1]));
                        usbd_xfer_set_frames(xfer, 2);
                        usbd_transfer_submit(xfer);

                } else if (sc->sc_mode == G_KEYBOARD_MODE_PATTERN) {
                        memset(&sc->sc_data, 0, sizeof(sc->sc_data));

                        if ((sc->sc_state < 0) || (sc->sc_state >= G_KEYBOARD_MAX_STRLEN))
                                sc->sc_state = 0;

                        switch (sc->sc_state % 6) {
                        case 0:
                                sc->sc_data[0].keycode[0] =
                                    g_keyboard_get_keycode(sc, sc->sc_state + 0);
                        case 1:
                                sc->sc_data[0].keycode[1] =
                                    g_keyboard_get_keycode(sc, sc->sc_state + 1);
                        case 2:
                                sc->sc_data[0].keycode[2] =
                                    g_keyboard_get_keycode(sc, sc->sc_state + 2);
                        case 3:
                                sc->sc_data[0].keycode[3] =
                                    g_keyboard_get_keycode(sc, sc->sc_state + 3);
                        case 4:
                                sc->sc_data[0].keycode[4] =
                                    g_keyboard_get_keycode(sc, sc->sc_state + 4);
                        default:
                                sc->sc_data[0].keycode[5] =
                                    g_keyboard_get_keycode(sc, sc->sc_state + 5);
                        }

                        sc->sc_state++;

                        usbd_xfer_set_frame_data(xfer, 0, &sc->sc_data[0], sizeof(sc->sc_data[0]));
                        usbd_xfer_set_frame_data(xfer, 1, &sc->sc_data[1], sizeof(sc->sc_data[1]));
                        usbd_xfer_set_frames(xfer, 2);
                        usbd_transfer_submit(xfer);
                }
                break;

        default:                        /* Error */
                DPRINTF("error=%s\n", usbd_errstr(error));

                if (error != USB_ERR_CANCELLED) {
                        /* try to clear stall first */
                        usbd_xfer_set_stall(xfer);
                        goto tr_setup;
                }
                break;
        }
}

static int
g_keyboard_handle_request(device_t dev,
    const void *preq, void **pptr, uint16_t *plen,
    uint16_t offset, uint8_t *pstate)
{
        struct g_keyboard_softc *sc = device_get_softc(dev);
        const struct usb_device_request *req = preq;
        uint8_t is_complete = *pstate;

        if (!is_complete) {
                if ((req->bmRequestType == UT_WRITE_CLASS_INTERFACE) &&
                    (req->bRequest == UR_SET_REPORT) &&
                    (req->wValue[0] == 0x00) &&
                    (req->wValue[1] == 0x02)) {
                        if (offset == 0) {
                                *plen = sizeof(sc->sc_led_state);
                                *pptr = &sc->sc_led_state;
                        } else {
                                *plen = 0;
                        }
                        return (0);
                } else if ((req->bmRequestType == UT_WRITE_CLASS_INTERFACE) &&
                            (req->bRequest == UR_SET_PROTOCOL) &&
                            (req->wValue[0] == 0x00) &&
                    (req->wValue[1] == 0x00)) {
                        *plen = 0;
                        return (0);
                } else if ((req->bmRequestType == UT_WRITE_CLASS_INTERFACE) &&
                    (req->bRequest == UR_SET_IDLE)) {
                        *plen = 0;
                        return (0);
                }
        }
        return (ENXIO);                 /* use builtin handler */
}