/*      $NetBSD: hid.c,v 1.8 2024/12/19 00:50:47 jmcneill Exp $ */
/*      $FreeBSD: src/sys/dev/usb/hid.c,v 1.11 1999/11/17 22:33:39 n_hibma Exp $ */

/*
 * Copyright (c) 1998 The NetBSD Foundation, Inc.
 * All rights reserved.
 *
 * This code is derived from software contributed to The NetBSD Foundation
 * by Lennart Augustsson (lennart@augustsson.net) at
 * Carlstedt Research & Technology.
 *
 * 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 NETBSD FOUNDATION, INC. 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 FOUNDATION 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>
__KERNEL_RCSID(0, "$NetBSD: hid.c,v 1.8 2024/12/19 00:50:47 jmcneill Exp $");

#ifdef _KERNEL_OPT
#include "opt_usb.h"
#endif

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

#include <dev/usb/usb.h>
#include <dev/usb/usbhid.h>

#include <dev/hid/hid.h>

#ifdef UHIDEV_DEBUG
#define DPRINTF(x)      if (uhidevdebug) printf x
#define DPRINTFN(n,x)   if (uhidevdebug>(n)) printf x
extern int uhidevdebug;
#else
#define DPRINTF(x)
#define DPRINTFN(n,x)
#endif

Static void hid_clear_local(struct hid_item *);

#define MAXUSAGE 256
struct hid_data {
        const u_char *start;
        const u_char *end;
        const u_char *p;
        struct hid_item cur;
        int32_t usages[MAXUSAGE];
        int nu;
        int minset;
        int multi;
        int multimax;
        enum hid_kind kind;
};

Static void
hid_clear_local(struct hid_item *c)
{

        DPRINTFN(5,("hid_clear_local\n"));
        c->usage = 0;
        c->usage_minimum = 0;
        c->usage_maximum = 0;
        c->designator_index = 0;
        c->designator_minimum = 0;
        c->designator_maximum = 0;
        c->string_index = 0;
        c->string_minimum = 0;
        c->string_maximum = 0;
        c->set_delimiter = 0;
}

struct hid_data *
hid_start_parse(const void *d, int len, enum hid_kind kind)
{
        struct hid_data *s;

        s = kmem_zalloc(sizeof(*s), KM_SLEEP);
        s->start = s->p = d;
        s->end = (const char *)d + len;
        s->kind = kind;
        return s;
}

void
hid_end_parse(struct hid_data *s)
{

        while (s->cur.next != NULL) {
                struct hid_item *hi = s->cur.next->next;
                kmem_free(s->cur.next, sizeof(*s->cur.next));
                s->cur.next = hi;
        }
        kmem_free(s, sizeof(*s));
}

int
hid_get_item(struct hid_data *s, struct hid_item *h)
{
        struct hid_item *c = &s->cur;
        unsigned int bTag, bType, bSize;
        uint32_t oldpos;
        const u_char *data;
        int32_t dval;
        uint32_t uval;
        const u_char *p;
        struct hid_item *hi;
        int i;
        enum hid_kind retkind;

 top:
        DPRINTFN(5,("hid_get_item: multi=%d multimax=%d\n",
                    s->multi, s->multimax));
        if (s->multimax != 0) {
                if (s->multi < s->multimax) {
                        c->usage = s->usages[uimin(s->multi, s->nu-1)];
                        s->multi++;
                        *h = *c;
                        c->loc.pos += c->loc.size;
                        h->next = NULL;
                        DPRINTFN(5,("return multi\n"));
                        return 1;
                } else {
                        c->loc.count = s->multimax;
                        s->multimax = 0;
                        s->nu = 0;
                        hid_clear_local(c);
                }
        }
        for (;;) {
                p = s->p;

                if (s->end - p < 1)
                        return 0;
                bSize = *p++;

                if (bSize == 0xfe) {
                        /* long item */
                        if (p + 3 > s->end)
                                return 0;
                        bSize = *p++;
                        bSize |= *p++ << 8;
                        bTag = *p++;
                        bType = 0xff; /* XXX what should it be */
                } else {
                        /* short item */
                        bTag = bSize >> 4;
                        bType = (bSize >> 2) & 3;
                        bSize &= 3;
                        if (bSize == 3)
                                bSize = 4;
                }

                data = p;
                if (bSize > s->end - p)
                        return 0;
                p += bSize;

                s->p = p;
                switch(bSize) {
                case 0:
                        dval = 0;
                        uval = dval;
                        break;
                case 1:
                        dval = *data++;
                        uval = dval;
                        dval = (int8_t)dval;
                        break;
                case 2:
                        dval = *data++;
                        dval |= *data++ << 8;
                        uval = dval;
                        dval = (int16_t)dval;
                        break;
                case 4:
                        dval = *data++;
                        dval |= *data++ << 8;
                        dval |= *data++ << 16;
                        dval |= *data++ << 24;
                        uval = dval;
                        dval = (int32_t)dval;
                        break;
                default:
                        aprint_normal("BAD LENGTH %d\n", bSize);
                        continue;
                }

                DPRINTFN(5,("hid_get_item: bType=%d bTag=%d dval=%d uval=%u\n",
                         bType, bTag, dval, uval));
                switch (bType) {
                case 0:                 /* Main */
                        switch (bTag) {
                        case 8:         /* Input */
                                retkind = hid_input;
                        ret:
                                if (s->kind != retkind) {
                                        s->minset = 0;
                                        s->nu = 0;
                                        hid_clear_local(c);
                                        continue;
                                }
                                c->kind = retkind;
                                c->flags = uval;
                                if (c->flags & HIO_VARIABLE) {
                                        s->multimax = c->loc.count;
                                        s->multi = 0;
                                        c->loc.count = 1;
                                        if (s->minset) {
                                                for (i = c->usage_minimum;
                                                     i <= c->usage_maximum;
                                                     i++) {
                                                        s->usages[s->nu] = i;
                                                        if (s->nu < MAXUSAGE-1)
                                                                s->nu++;
                                                }
                                                s->minset = 0;
                                        }
                                        goto top;
                                } else {
                                        if (s->minset)
                                                c->usage = c->usage_minimum;
                                        *h = *c;
                                        h->next = NULL;
                                        c->loc.pos +=
                                            c->loc.size * c->loc.count;
                                        s->minset = 0;
                                        s->nu = 0;
                                        hid_clear_local(c);
                                        return 1;
                                }
                        case 9:         /* Output */
                                retkind = hid_output;
                                goto ret;
                        case 10:        /* Collection */
                                c->kind = hid_collection;
                                c->collection = uval;
                                c->collevel++;
                                *h = *c;
                                hid_clear_local(c);
                                s->nu = 0;
                                return 1;
                        case 11:        /* Feature */
                                retkind = hid_feature;
                                goto ret;
                        case 12:        /* End collection */
                                c->kind = hid_endcollection;
                                c->collevel--;
                                *h = *c;
                                s->nu = 0;
                                return 1;
                        default:
                                aprint_normal("Main bTag=%d\n", bTag);
                                break;
                        }
                        break;
                case 1:         /* Global */
                        switch (bTag) {
                        case 0:
                                c->_usage_page = uval << 16;
                                break;
                        case 1:
                                c->logical_minimum = dval;
                                break;
                        case 2:
                                c->logical_maximum = dval;
                                break;
                        case 3:
                                c->physical_minimum = dval;
                                break;
                        case 4:
                                c->physical_maximum = dval;
                                break;
                        case 5:
                                c->unit_exponent = uval;
                                break;
                        case 6:
                                c->unit = uval;
                                break;
                        case 7:
                                c->loc.size = uval;
                                break;
                        case 8:
                                c->report_ID = uval;
                                c->loc.pos = 0;
                                break;
                        case 9:
                                c->loc.count = uval;
                                break;
                        case 10: /* Push */
                                hi = kmem_alloc(sizeof(*hi), KM_SLEEP);
                                *hi = *c;
                                c->next = hi;
                                break;
                        case 11: /* Pop */
                                hi = c->next;
                                if (hi == NULL)
                                        break;
                                oldpos = c->loc.pos;
                                *c = *hi;
                                c->loc.pos = oldpos;
                                kmem_free(hi, sizeof(*hi));
                                break;
                        default:
                                aprint_normal("Global bTag=%d\n", bTag);
                                break;
                        }
                        break;
                case 2:         /* Local */
                        switch (bTag) {
                        case 0:
                                if (bSize < 4)
                                        uval = c->_usage_page | uval;
                                c->usage = uval;
                                if (s->nu < MAXUSAGE)
                                        s->usages[s->nu++] = uval;
                                /* else XXX */
                                break;
                        case 1:
                                s->minset = 1;
                                if (bSize < 4)
                                        uval = c->_usage_page | uval;
                                c->usage_minimum = uval;
                                break;
                        case 2:
                                if (bSize < 4)
                                        uval = c->_usage_page | uval;
                                c->usage_maximum = uval;
                                break;
                        case 3:
                                c->designator_index = uval;
                                break;
                        case 4:
                                c->designator_minimum = uval;
                                break;
                        case 5:
                                c->designator_maximum = uval;
                                break;
                        case 7:
                                c->string_index = uval;
                                break;
                        case 8:
                                c->string_minimum = uval;
                                break;
                        case 9:
                                c->string_maximum = uval;
                                break;
                        case 10:
                                c->set_delimiter = uval;
                                break;
                        default:
                                aprint_normal("Local bTag=%d\n", bTag);
                                break;
                        }
                        break;
                default:
                        aprint_normal("default bType=%d\n", bType);
                        break;
                }
        }
}

int
hid_report_size(const void *buf, int len, enum hid_kind k, uint8_t id)
{
        struct hid_data *d;
        struct hid_item h;
        int lo, hi;

        h.report_ID = 0;
        lo = hi = -1;
        DPRINTFN(2,("hid_report_size: kind=%d id=%d\n", k, id));
        for (d = hid_start_parse(buf, len, k); hid_get_item(d, &h); ) {
                DPRINTFN(2,("hid_report_size: item kind=%d id=%d pos=%d "
                            "size=%d count=%d\n",
                            h.kind, h.report_ID, h.loc.pos, h.loc.size,
                            h.loc.count));
                if (h.report_ID == id && h.kind == k) {
                        if (lo < 0) {
                                lo = h.loc.pos;
#ifdef DIAGNOSTIC
                                if (lo != 0) {
                                        aprint_normal("hid_report_size:"
                                           " lo != 0\n");
                                }
#endif
                        }
                        hi = h.loc.pos + h.loc.size * h.loc.count;
                        DPRINTFN(2,("hid_report_size: lo=%d hi=%d\n", lo, hi));
                }
        }
        hid_end_parse(d);
        return (hi - lo + 7) / 8;
}

int
hid_locate(const void *desc, int size, uint32_t u, uint8_t id, enum hid_kind k,
           struct hid_location *loc, uint32_t *flags)
{
        struct hid_data *d;
        struct hid_item h;

        h.report_ID = 0;
        DPRINTFN(5,("hid_locate: enter usage=0x%x kind=%d id=%d\n", u, k, id));
        for (d = hid_start_parse(desc, size, k); hid_get_item(d, &h); ) {
                DPRINTFN(5,("hid_locate: usage=0x%x kind=%d id=%d flags=0x%x\n",
                            h.usage, h.kind, h.report_ID, h.flags));
                if (h.kind == k && !(h.flags & HIO_CONST) &&
                    h.usage == u && h.report_ID == id) {
                        if (loc != NULL)
                                *loc = h.loc;
                        if (flags != NULL)
                                *flags = h.flags;
                        hid_end_parse(d);
                        return 1;
                }
        }
        hid_end_parse(d);
        if (loc != NULL)
                loc->size = 0;
        return 0;
}

long
hid_get_data(const u_char *buf, const struct hid_location *loc)
{
        u_int hsize = loc->size;
        u_long data;

        if (hsize == 0)
                return 0;

        data = hid_get_udata(buf, loc);
        if (data < (1UL << (hsize - 1)) || hsize == sizeof(data) * NBBY)
                return data;
        return data - (1UL << hsize);
}

u_long
hid_get_udata(const u_char *buf, const struct hid_location *loc)
{
        u_int hpos = loc->pos;
        u_int hsize = loc->size;
        u_int i, num, off;
        u_long data;

        if (hsize == 0)
                return 0;

        data = 0;
        off = hpos / 8;
        num = (hpos + hsize + 7) / 8 - off;

        for (i = 0; i < num; i++)
                data |= (unsigned long)buf[off + i] << (i * 8);

        data >>= hpos % 8;
        if (hsize < sizeof(data) * NBBY)
                data &= (1UL << hsize) - 1;

        DPRINTFN(10,("hid_get_udata: loc %d/%d = %lu\n", hpos, hsize, data));
        return data;
}

/*
 * hid_is_collection(desc, size, id, usage)
 *
 * This function is broken in the following way.
 *
 * It is used to discover if the given 'id' is part of 'usage' collection
 * in the descriptor in order to match report id against device type.
 *
 * The semantics of hid_start_parse() means though, that only a single
 * kind of report is considered. The current HID code that uses this for
 * matching is actually only looking for input reports, so this works
 * for now.
 *
 * This function could try all report kinds (input, output and feature)
 * consecutively if necessary, but it may be better to integrate the
 * libusbhid code which can consider multiple report kinds simultaneously
 *
 * Needs some thought.
 */
int
hid_is_collection(const void *desc, int size, uint8_t id, uint32_t usage)
{
        struct hid_data *hd;
        struct hid_item hi;
        uint32_t coll_usage = ~0;

        hd = hid_start_parse(desc, size, hid_input);
        if (hd == NULL)
                return 0;

        DPRINTFN(2,("hid_is_collection: id=%d usage=0x%x\n", id, usage));
        while (hid_get_item(hd, &hi)) {
                DPRINTFN(2,("hid_is_collection: kind=%d id=%d usage=0x%x"
                            "(0x%x)\n",
                            hi.kind, hi.report_ID, hi.usage, coll_usage));

                if (hi.kind == hid_collection &&
                    (hi.collection == HCOLL_APPLICATION ||
                    hi.collection == HCOLL_PHYSICAL ||
                    hi.collection == HCOLL_LOGICAL))
                        coll_usage = hi.usage;

                if ((hi.kind == hid_collection ||
                     hi.kind == hid_endcollection) &&
                    coll_usage == usage &&
                    hi.report_ID == id) {
                        DPRINTFN(2,("hid_is_collection: found\n"));
                        hid_end_parse(hd);
                        return 1;
                }

                if (hi.kind == hid_endcollection)
                        coll_usage = ~0;
        }
        DPRINTFN(2,("hid_is_collection: not found\n"));
        hid_end_parse(hd);
        return 0;
}