/*-
 * SPDX-License-Identifier: BSD-2-Clause
 *
 * Copyright (c) 2009, Oleksandr Tymoshenko <gonzo@FreeBSD.org>
 * Copyright (c) 2014, Rui Paulo <rpaulo@FreeBSD.org>
 * Copyright (c) 2015, Emmanuel Vadot <manu@bidouilliste.com>
 * 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 unmodified, 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.
 */

#include <sys/cdefs.h>
#include <fcntl.h>
#include <getopt.h>
#include <paths.h>
#include <stdio.h>
#include <stdarg.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

#include <libgpio.h>

#define PIN_TYPE_NUMBER         1
#define PIN_TYPE_NAME           2

struct flag_desc {
        const char *name;
        uint32_t flag;
};

static struct flag_desc gpio_flags[] = {
        { "IN", GPIO_PIN_INPUT },
        { "OUT", GPIO_PIN_OUTPUT },
        { "OD", GPIO_PIN_OPENDRAIN },
        { "PP", GPIO_PIN_PUSHPULL },
        { "TS", GPIO_PIN_TRISTATE },
        { "PU", GPIO_PIN_PULLUP },
        { "PD", GPIO_PIN_PULLDOWN },
        { "II", GPIO_PIN_INVIN },
        { "IO", GPIO_PIN_INVOUT },
        { "PULSE", GPIO_PIN_PULSATE },
        { "INTRLL", GPIO_INTR_LEVEL_LOW},
        { "INTRLH", GPIO_INTR_LEVEL_HIGH},
        { "INTRER", GPIO_INTR_EDGE_RISING},
        { "INTREF", GPIO_INTR_EDGE_FALLING},
        { "INTREB", GPIO_INTR_EDGE_BOTH},
        { NULL, 0 },
};

int str2cap(const char *str);

static void
usage(void)
{
        fprintf(stderr, "Usage:\n");
        fprintf(stderr, "\tgpioctl [-f ctldev] -l [-v]\n");
        fprintf(stderr, "\tgpioctl [-f ctldev] [-pN] -t pin\n");
        fprintf(stderr, "\tgpioctl [-f ctldev] [-pN] -c pin flag ...\n");
        fprintf(stderr, "\tgpioctl [-f ctldev] [-pN] -n pin pin-name\n");
        fprintf(stderr, "\tgpioctl [-f ctldev] [-pN] pin [0|1]\n");
        exit(1);
}

static const char *
cap2str(uint32_t cap)
{
        struct flag_desc * pdesc = gpio_flags;
        while (pdesc->name) {
                if (pdesc->flag == cap)
                        return pdesc->name;
                pdesc++;
        }

        return "UNKNOWN";
}

int
str2cap(const char *str)
{
        struct flag_desc * pdesc = gpio_flags;
        while (pdesc->name) {
                if (strcasecmp(str, pdesc->name) == 0)
                        return pdesc->flag;
                pdesc++;
        }

        return (-1);
}

/*
 * Our handmade function for converting string to number
 */
static int
str2int(const char *s, int *ok)
{
        char *endptr;
        int res = strtod(s, &endptr);
        if (endptr != s + strlen(s) )
                *ok = 0;
        else
                *ok = 1;

        return res;
}

static void
print_caps(int caps)
{
        int i, need_coma;

        need_coma = 0;
        printf("<");
        for (i = 0; i < 32; i++) {
                if (caps & (1 << i)) {
                        if (need_coma)
                                printf(",");
                        printf("%s", cap2str(1 << i));
                        need_coma = 1;
                }
        }
        printf(">");
}

static void
dump_pins(gpio_handle_t handle, int verbose)
{
        int i, maxpin, pinv;
        gpio_config_t *cfgs;
        gpio_config_t *pin;

        maxpin = gpio_pin_list(handle, &cfgs);
        if (maxpin < 0) {
                perror("gpio_pin_list");
                exit(1);
        }

        for (i = 0; i <= maxpin; i++) {
                pin = cfgs + i;
                pinv = gpio_pin_get(handle, pin->g_pin);
                printf("pin %02d:\t%d\t%s", pin->g_pin, pinv,
                    pin->g_name);

                print_caps(pin->g_flags);

                if (verbose) {
                        printf(", caps:");
                        print_caps(pin->g_caps);
                }
                printf("\n");
        }
        free(cfgs);
}

static int
get_pinnum_by_name(gpio_handle_t handle, const char *name) {
        int i, maxpin, pinn;
        gpio_config_t *cfgs;
        gpio_config_t *pin;

        pinn = -1;
        maxpin = gpio_pin_list(handle, &cfgs);
        if (maxpin < 0) {
                perror("gpio_pin_list");
                exit(1);
        }

        for (i = 0; i <= maxpin; i++) {
                pin = cfgs + i;
                gpio_pin_get(handle, pin->g_pin);
                if (!strcmp(name, pin->g_name)) {
                        pinn = i;
                        break;
                }
        }
        free(cfgs);

        return pinn;
}

static void
fail(const char *fmt, ...)
{
        va_list ap;

        va_start(ap, fmt);
        vfprintf(stderr, fmt, ap);
        va_end(ap);
        exit(1);
}

int
main(int argc, char **argv)
{
        int i;
        gpio_config_t pin;
        gpio_handle_t handle;
        char *ctlfile = NULL;
        int pinn, pinv, pin_type, ch;
        int flags, flag, ok;
        int config, list, name, toggle, verbose;

        config = toggle = verbose = list = name = pin_type = 0;

        while ((ch = getopt(argc, argv, "cf:lntvNp")) != -1) {
                switch (ch) {
                case 'c':
                        config = 1;
                        break;
                case 'f':
                        ctlfile = optarg;
                        break;
                case 'l':
                        list = 1;
                        break;
                case 'n':
                        name = 1;
                        break;
                case 'N':
                        pin_type = PIN_TYPE_NAME;
                        break;
                case'p':
                        pin_type = PIN_TYPE_NUMBER;
                        break;
                case 't':
                        toggle = 1;
                        break;
                case 'v':
                        verbose = 1;
                        break;
                default:
                        usage();
                        break;
                }
        }
        argv += optind;
        argc -= optind;
        if (ctlfile == NULL)
                handle = gpio_open(0);
        else
                handle = gpio_open_device(ctlfile);
        if (handle == GPIO_INVALID_HANDLE) {
                perror("gpio_open");
                exit(1);
        }

        if (list) {
                dump_pins(handle, verbose);
                gpio_close(handle);
                exit(0);
        }

        if (argc == 0)
                usage();

        /* Find the pin number by the name */
        switch (pin_type) {
        default:
                /* First test if it is a pin number */
                pinn = str2int(argv[0], &ok);
                if (ok) {
                        /* Test if we have any pin named by this number and tell the user */
                        if (get_pinnum_by_name(handle, argv[0]) != -1)
                                fail("%s is also a pin name, use -p or -N\n", argv[0]);
                } else {
                        /* Test if it is a name */
                        if ((pinn = get_pinnum_by_name(handle, argv[0])) == -1)
                                fail("Can't find pin named \"%s\"\n", argv[0]);
                }
                break;
        case PIN_TYPE_NUMBER:
                pinn = str2int(argv[0], &ok);
                if (!ok)
                        fail("Invalid pin number: %s\n", argv[0]);
                break;
        case PIN_TYPE_NAME:
                if ((pinn = get_pinnum_by_name(handle, argv[0])) == -1)
                        fail("Can't find pin named \"%s\"\n", argv[0]);
                break;
        }

        /* Set the pin name. */
        if (name) {
                if (argc != 2)
                        usage();
                if (gpio_pin_set_name(handle, pinn, argv[1]) < 0) {
                        perror("gpio_pin_set_name");
                        exit(1);
                }
                exit(0);
        }

        if (toggle) {
                /*
                * -t pin assumes no additional arguments
                */
                if (argc > 1)
                        usage();
                if (gpio_pin_toggle(handle, pinn) < 0) {
                        perror("gpio_pin_toggle");
                        exit(1);
                }
                gpio_close(handle);
                exit(0);
        }

        if (config) {
                flags = 0;
                for (i = 1; i < argc; i++) {
                        flag =  str2cap(argv[i]);
                        if (flag < 0)
                                fail("Invalid flag: %s\n", argv[i]);
                        else if ((flag & GPIO_INTR_MASK) != 0)
                                fail("Interrupt capability %s cannot be set as configuration flag\n", argv[i]);
                        flags |= flag;
                }
                pin.g_pin = pinn;
                pin.g_flags = flags;
                if (gpio_pin_set_flags(handle, &pin) < 0) {
                        perror("gpio_pin_set_flags");
                        exit(1);
                }
                exit(0);
        }

        /*
         * Last two cases - set value or print value
         */
        if ((argc == 0) || (argc > 2))
                usage();

        /*
         * Read pin value
         */
        if (argc == 1) {
                pinv = gpio_pin_get(handle, pinn);
                if (pinv < 0) {
                        perror("gpio_pin_get");
                        exit(1);
                }
                printf("%d\n", pinv);
                exit(0);
        }

        /* Is it valid number (0 or 1) ? */
        pinv = str2int(argv[1], &ok);
        if (ok == 0 || ((pinv != 0) && (pinv != 1)))
                fail("Invalid pin value: %s\n", argv[1]);

        /*
         * Set pin value
         */
        if (gpio_pin_set(handle, pinn, pinv) < 0) {
                perror("gpio_pin_set");
                exit(1);
        }

        gpio_close(handle);
        exit(0);
}