/*-
 * SPDX-License-Identifier: BSD-2-Clause
 *
 * Copyright (C) 2004 Joerg Wunsch
 * 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 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 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.
 */

/*
 * Send or receive messages over an SMBus.
 */

#include <err.h>
#include <errno.h>
#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sysexits.h>
#include <unistd.h>

#include <sys/types.h>
#include <sys/ioctl.h>

#include <dev/smbus/smb.h>

#include "pathnames.h"

static const char *dev = PATH_DEFAULTSMBDEV;
static const char *bytefmt = "0x%02x";
static const char *wordfmt = "0x%04x";
static const char *fmt;

static int fd;                  /* file descriptor for /dev/smbX */
static int cflag = -1;          /* SMBus cmd */
static int iflag = -1;          /* input data */
static int oflag = -1;          /* output data */
static int pflag;               /* probe bus */
static int slave = -1;          /* slave address */
static int wflag;               /* word IO */

static unsigned char ibuf[SMB_MAXBLOCKSIZE];
static unsigned char obuf[SMB_MAXBLOCKSIZE];
static unsigned short oword;

/*
 * The I2C specs say that all addresses below 16 and above or equal
 * 240 are reserved.  Address 0 is the global address, but we do not
 * care for this detail.
 */
#define MIN_I2C_ADDR    16
#define MAX_I2C_ADDR    240

static int      do_io(void);
static int      getnum(const char *s);
static void     probe_i2c(void);
static void     usage(void);

static void
usage(void)
{
        fprintf(stderr,
                "usage: smbmsg [-f dev] -p\n"
                "       smbmsg [-f dev] -s slave [-F fmt] [-c cmd] [-w] "
                "[-i incnt] [-o outcnt] [outdata ...]\n");
        exit(EX_USAGE);
}

static int
getnum(const char *s)
{
        char *endp;
        unsigned long l;

        l = strtoul(s, &endp, 0);
        if (*s != '\0' && *endp == '\0')
                return (int)l;
        return (-1);
}

static void
probe_i2c(void)
{
        unsigned char addr;
        int flags;
#define IS_READABLE     1
#define IS_WRITEABLE    2
        struct smbcmd c;

        printf("Probing for devices on %s:\n", dev);

        for (addr = MIN_I2C_ADDR; addr < MAX_I2C_ADDR; addr += 2) {
                c.slave = addr;
                flags = 0;
                if (ioctl(fd, SMB_RECVB, &c) != -1)
                        flags = IS_READABLE;
                if (ioctl(fd, SMB_QUICK_WRITE, &c) != -1)
                        flags |= IS_WRITEABLE;
                if (flags != 0) {
                        printf("Device @0x%02x: ", addr);
                        if (flags & IS_READABLE)
                                putchar('r');
                        if (flags & IS_WRITEABLE)
                                putchar('w');
                        putchar('\n');
                }
        }
}

static int
do_io(void)
{
        struct smbcmd c;
        int i;

        c.slave = slave;
        c.cmd = cflag;
        c.rcount = 0;
        c.wcount = 0;

        if (fmt == NULL && iflag > 0)
                fmt = wflag? wordfmt: bytefmt;

        if (cflag == -1) {
                /* operations that do not require a command byte */
                if (iflag == -1 && oflag == 0)
                        /* 0 bytes output: quick write operation */
                        return (ioctl(fd, SMB_QUICK_WRITE, &c));
                else if (iflag == 0 && oflag == -1)
                        /* 0 bytes input: quick read operation */
                        return (ioctl(fd, SMB_QUICK_READ, &c));
                else if (iflag == 1 && oflag == -1) {
                        /* no command, 1 byte input: receive byte op. */
                        if (ioctl(fd, SMB_RECVB, &c) == -1)
                                return (-1);
                        printf(fmt, (unsigned char)c.cmd);
                        putchar('\n');
                        return (0);
                } else if (iflag == -1 && oflag == 1) {
                        /* no command, 1 byte output: send byte op. */
                        c.cmd = obuf[0];
                        return (ioctl(fd, SMB_SENDB, &c));
                } else
                        return (-2);
        }
        if (iflag == 1 && oflag == -1) {
                /* command + 1 byte input: read byte op. */
                if (ioctl(fd, SMB_READB, &c) == -1)
                        return (-1);
                printf(fmt, (unsigned char)c.rdata.byte);
                putchar('\n');
                return (0);
        } else if (iflag == -1 && oflag == 1) {
                /* command + 1 byte output: write byte op. */
                c.wdata.byte = obuf[0];
                return (ioctl(fd, SMB_WRITEB, &c));
        } else if (wflag && iflag == 2 && oflag == -1) {
                /* command + 2 bytes input: read word op. */
                if (ioctl(fd, SMB_READW, &c) == -1)
                        return (-1);
                printf(fmt, (unsigned short)c.rdata.word);
                putchar('\n');
                return (0);
        } else if (wflag && iflag == -1 && oflag == 2) {
                /* command + 2 bytes output: write word op. */
                c.wdata.word = oword;
                return (ioctl(fd, SMB_WRITEW, &c));
        } else if (wflag && iflag == 2 && oflag == 2) {
                /*
                 * command + 2 bytes output + 2 bytes input:
                 * "process call" op.
                 */
                c.wdata.word = oword;
                if (ioctl(fd, SMB_PCALL, &c) == -1)
                        return (-1);
                printf(fmt, (unsigned short)c.rdata.word);
                putchar('\n');
                return (0);
        } else if (iflag > 1 && oflag == -1) {
                /* command + > 1 bytes of input: block read */
                c.rbuf = ibuf;
                c.rcount = iflag;
                if (ioctl(fd, SMB_BREAD, &c) == -1)
                        return (-1);
                for (i = 0; i < c.rcount; i++) {
                        if (i != 0)
                                putchar(' ');
                        printf(fmt, ibuf[i]);
                }
                putchar('\n');
                return (0);
        } else if (iflag == -1 && oflag > 1) {
                /* command + > 1 bytes of output: block write */
                c.wbuf = obuf;
                c.wcount = oflag;
                return (ioctl(fd, SMB_BWRITE, &c));
        }

        return (-2);
}


int
main(int argc, char **argv)
{
        int i, n, errs = 0;
        int savederrno;

        while ((i = getopt(argc, argv, "F:c:f:i:o:ps:w")) != -1)
                switch (i) {
                case 'F':
                        fmt = optarg;
                        break;

                case 'c':
                        if ((cflag = getnum(optarg)) == -1)
                                errx(EX_USAGE, "Invalid number: %s", optarg);
                        if (cflag < 0 || cflag >= 256)
                                errx(EX_USAGE,
                                     "CMD out of range: %d",
                                     cflag);
                        break;

                case 'f':
                        dev = optarg;
                        break;

                case 'i':
                        if ((iflag = getnum(optarg)) == -1)
                                errx(EX_USAGE, "Invalid number: %s", optarg);
                        if (iflag < 0 || iflag > SMB_MAXBLOCKSIZE)
                                errx(EX_USAGE,
                                     "# input bytes out of range: %d",
                                     iflag);
                        break;

                case 'o':
                        if ((oflag = getnum(optarg)) == -1)
                                errx(EX_USAGE, "Invalid number: %s", optarg);
                        if (oflag < 0 || oflag > SMB_MAXBLOCKSIZE)
                                errx(EX_USAGE,
                                     "# output bytes out of range: %d",
                                     oflag);
                        break;

                case 'p':
                        pflag = 1;
                        break;

                case 's':
                        if ((slave = getnum(optarg)) == -1)
                                errx(EX_USAGE, "Invalid number: %s", optarg);

                        if (slave < MIN_I2C_ADDR || slave >= MAX_I2C_ADDR)
                                errx(EX_USAGE,
                                     "Slave address out of range: %d",
                                     slave);
                        break;

                case 'w':
                        wflag = 1;
                        break;

                default:
                        errs++;
                }
        argc -= optind;
        argv += optind;
        if (errs || (slave != -1 && pflag) || (slave == -1 && !pflag))
                usage();
        if (wflag &&
            !((iflag == 2 && oflag == -1) ||
              (iflag == -1 && oflag == 2) ||
              (iflag == 2 && oflag == 2)))
                errx(EX_USAGE, "Illegal # IO bytes for word IO");
        if (!pflag && iflag == -1 && oflag == -1)
                errx(EX_USAGE, "Nothing to do");
        if (pflag && (cflag != -1 || iflag != -1 || oflag != -1 || wflag != 0))
                usage();
        if (oflag > 0) {
                if (oflag == 2 && wflag) {
                        if (argc == 0)
                                errx(EX_USAGE, "Too few arguments for -o count");
                        if ((n = getnum(*argv)) == -1)
                                errx(EX_USAGE, "Invalid number: %s", *argv);
                        if (n < 0 || n >= 65535)
                                errx(EX_USAGE, "Value out of range: %d", n);
                        oword = n;
                        argc--;
                        argv++;
                } else for (i = 0; i < oflag; i++, argv++, argc--) {
                        if (argc == 0)
                                errx(EX_USAGE, "Too few arguments for -o count");
                        if ((n = getnum(*argv)) == -1)
                                errx(EX_USAGE, "Invalid number: %s", *argv);
                        if (n < 0 || n >= 256)
                                errx(EX_USAGE, "Value out of range: %d", n);
                        obuf[i] = n;
                }
        }
        if (argc != 0)
                usage();

        if ((fd = open(dev, O_RDWR)) == -1)
                err(EX_UNAVAILABLE, "Cannot open %s", dev);

        i = 0;
        if (pflag)
                probe_i2c();
        else
                i = do_io();

        savederrno = errno;
        close(fd);
        errno = savederrno;

        if (i == -1)
                err(EX_UNAVAILABLE, "Error performing SMBus IO");
        else if (i == -2)
                errx(EX_USAGE, "Invalid option combination");

        return (0);
}